Patent application title: DEVICES AND METHOD FOR SPORTS AND/OR AQUATIC ENVIRONMENTS
Dean Sharples (Templestowe, AU)
IPC8 Class: AA63B7106FI
Class name: Horology: time measuring systems or devices time interval mechanical stop time type
Publication date: 2015-03-05
Patent application number: 20150063081
The present invention relates to devices and methods for sports and other
physical training. In some embodiments, the devices and methods are
adapted for use in relation to aquatic environments or pursuits. In some
forms, the invention relates to timing devices and associated methods. In
other forms, invention relates to a communication device and a wearable
item incorporating the communication device.
1. A method of timing a plurality of events that overlap in time using a
common time keeping device, the method including, for each event:
determining a start of the event; determining an elapsed time since the
start of the event, and in the case that the that the elapsed time is
greater than a maximum expected duration of the event, subtracting a
start interval from the elapsed time of the event, said start interval
representing a time interval between the start of the event and a start
of a preceding event.
2. The method according to claim 1, wherein the step of determining a start of the event includes deeming that the event starts at a scheduled time that is offset from the start time of the preceding event by the start interval, wherein the start interval is predefined.
3. The method according to claim 1, wherein the method further includes determining an end of the event and determining the duration of the event as the elapsed time of the event at the end of the event.
4. The method according to claim 1, wherein the method further includes determining the maximum expected duration of the event on the basis of a recorded duration of a first event in the plurality of events.
5. The method according to claim 4, wherein the maximum expected duration of the event is calculated according to: maximum expected duration = duration of first event + start interval 2 ##EQU00002##
6. The method according to claim 1, wherein the step of determining a start of each event includes triggering the start of each event.
7. The method according to claim 6, wherein the method further includes signalling the start of the event to a device that is external to the time keeping device, or to a user.
8. The method according to claim 7, wherein the time of signalling is offset from the time of said triggering.
9. The method according to claim 6, wherein the start of each event is the time of triggering the event.
11. The method according to claim 1, wherein the method is performed in a portable device suitably programmed to act as a timing device.
12. The method according to claim 11, wherein the portable device is a stopwatch.
13. The method according to claim 1, wherein the method includes signalling a duration of the event to a device that is external to the time keeping device, or to a user.
14. The method according to claim 13, wherein the signalled duration is represented as an offset relative to a base time.
15. The method according to claim 14, wherein the base time is one of: a multiple of 10 seconds or a minute, a target time, or a record time.
16. A method of timing events using a common time keeping device, wherein the method includes: a) timing a first plurality of events that overlap in time using a method in accordance with claim 1 b) once a first cycle time has elapsed since commencing said timing of the first plurality of events, timing a second plurality of events that overlap in time using a method in accordance with claim 1.
40. A method in a timing system for timing an aspect of a sporting pursuit, the method including: starting timing upon the occurrence of an event; detecting a plurality of inputs to the timing device, indicating a corresponding plurality of time measurements, each input representing an instant at which a participant in the sporting pursuit meets a predetermined position along a course; and on the basis of the plurality of inputs determining a speed of the participant between pairs of said positions along the course.
43. The method according to claim 40, wherein the method includes displaying the speed of the participant between a plurality of pairs of positions along the course simultaneously on an interface of the timing system.
44. A method of determining a timing of an event using a timing device operated by a human operator, the method including: receiving at the timing device a first input indicating the occurrence of the incident; determining a time of said input; and determining a corrected first input time by correcting the determined time of the first input to account for a delay in reaction of the operator to the occurrence of the incident.
48. The method according to claim 47, wherein the method includes receiving at the timing device a second input indicating the occurrence of the second incident and determining a time of said second input, and wherein in the event that the operator of the timing device estimates the occurrence of the second incident, the method includes determining the elapsed time between the first and second incidents on the basis of the corrected first input time and the determined time of the second input.
49. The method according to claim 44, wherein the step of correcting the determined time of the first input to account for a delay in reaction of the operator to the occurrence of the incident includes determining the corrected first input time to be earlier than the first input time by a correction factor representing the operator's reaction time.
FIELD OF THE INVENTION
 The present invention relates to devices and methods for sports and other physical training. In some embodiments, the devices and methods are adapted for use in relation to aquatic environments or pursuits. It is appreciated however, that various aspects of the invention may be used for other purposes.
 Several aspects of the present invention relate to timing devices and systems, or methods to be used in timing devices and systems. The preferred embodiment of these aspects of the invention will be described in the context of timing sporting pursuits, and in particular swimming. However, some aspects of the present invention will find application in timing devices more generally. The timing methods should be considered to be applicable to a wide variety of activities including, but not limited to, horse (or other animal) racing, motor (or other vehicle) racing, military and other physical training, athletics and other sporting pursuits.
 Other aspects of the present invention relate to communication systems. The systems are preferably for aquatic environments, such as might be used by a swimmer. Such communication systems may alternatively be employed on water-borne vehicles or bodies.
BACKGROUND OF THE INVENTION
 In coaching a group or `Squad` of athletes, a coach may typically use two or more stopwatches, a pace clock, a whistle and a loud voice in order to direct training and gather performance data for the athletes. Typically two stopwatches are required, as often a coach will arrange pairs of athletes to compete "one on one" so as to give an element of competition or pacing. After the athletes perform one cycle or "set", the coach would read their elapsed times or split times (being a time for a segment of the set, or lap, or the like) and announce these times to the athletes, so as to provide feedback as to their performance. Analysis of the coaches' duties indicates a substantial amount of time is devoted to these tasks, thereby reducing the amount of time for other important coaching duties. In addition, it is sometimes difficult for the coach to be as precise as required, due to human reflexes and limits on their attention. By way of example, consider a coach timing for two athletes using a conventional stopwatch. A conventional stopwatch typically has four primary states, controlled by two buttons. The right button is "Start/Stop" whilst the left button is "Split/Reset". In timing an athlete the coach would typically perform these tasks:
 1 Press "Reset" so as to set the timing display to 0.00 seconds.
 2 At the desired instant in time, a start event is signalled to the athlete(s) and the "Start" button is pressed as precisely as possible to this event as possible.
 3. After each successive lap or milestone, the "Split" button is pressed, the watch displaying both a Split time and the last cumulative time on the display. Some watches also display a split count number as well.
 4 At the conclusion of the training set, the "Stop" button is pressed, the stopwatch now statically displays the cumulative and last split time recorded.
 In a "One on One" race, the coach needs to perform these tasks for two athletes using two stopwatches at once.
 Moreover, in advanced training techniques a coach may want even finer grained data such as athlete velocity, stroke or stride rate. To do this, conventional stopwatches must be manually configured to the appropriate measurement mode, and cannot cope with uneven interval sizes, such as those typically marked on lane ropes in a 50M Olympic pool. Manual computation post event is required for such detailed analysis, yet this information is needed quickly by coaches in assessing race performance.
 Similar considerations arise in timing events or activities of other types.
 Accordingly there is a need for improved devices and systems for timekeeping. Improved methods of timing events would also be advantageous.
 Additionally, it can be challenging for the coach to communicate with the athlete(s) to let them know the timing data or other useful information, during training or competition. To assist communication, an athlete may wear a communication device that is capable of wirelessly communicating with a communication device at the other person. However, in some circumstances, the athlete's environment may compromise the transmitting and/or receiving of wireless signals by the athlete's communication device.
 This challenge is particularly problematic for swimmers, because high frequency radio waves do not permeate water easily, making it difficult to effectively communicate with the swimmer.
 One solution is to transmit high power signals to and from the swimmer. However, this results in a low battery life for the communication devices, or requires relatively expensive and large batteries.
 It would be desirable to provide a communication device that addresses this problem, while keeping power consumption of the athlete's device, and/or of the device with which it communicates, at a relatively low level.
 Reference to any prior art in the specification is not, and should not be taken as, an acknowledgment or any form of suggestion that this prior art forms part of the common general knowledge in Australia or any other jurisdiction or that this prior art could reasonably be expected to be ascertained, understood and regarded as relevant by a person skilled in the art.
SUMMARY OF THE INVENTION
 In one aspect the present invention provides a portable timing device, comprising:
 a time keeping mechanism;
 an interface for indicating timing data to a user of the device;
 said timing device being configured to operate in at least two selectable timing modes;
 an actuator operable by a user to input timing controls into the timing device wherein the actuator is operable to receive a control input of a first kind to indicate a first type of input; and a control input of a second kind to indicate a second type of input.
 Preferably the control input of a first kind is a rotational input by the user.
 Preferably the control input of a second kind is a pressing input by the user.
 Preferably the control input of a first kind causes the timing device to select a control mode from the at least two timing modes.
 Preferably control input of the second kind triggers a timing action within a timing mode.
 In the preferred form the actuator is a button capable of rotary and reciprocating motion wherein rotary motion of the button provides the second kind of control input and the reciprocating motion provides the first kind of control input.
 The button is preferably connected to a rotary encoder and a switch to convert motion of the button into control inputs.
 In another form the inputs of the first and second kind can be distinguished on the basis of one or more of the following criteria:
 a duration of one or more interactions;
 a number of interactions;
 a rate of interaction;
 a type of motion contained in the interaction.
 In one form the portable timing device includes a plurality of actuators of the type mentioned above.
 a stopwatch having:
 time keeping mechanism;
 an interface for indicating timing data to a user of the device;
 an actuator operable by a user to input a timing control into the timing device; wherein the stopwatch is configured to distinguish between a plurality of different user interactions with the actuator to distinguish between respective ones of a plurality of timing controls input by the user.
 The stopwatch can be configured to distinguish between different user interactions on one or more of the following criteria:
 a duration of one or more interactions;
 a number of interactions;
 a rate of interaction;
 a type of motion contained in the interaction.
 In one form the actuator can be a button. In this case the interaction can be presses of the button. The stopwatch can be configured to identify one of more of the following user interactions with the button:
 a single button press;
 a double button press;
 a short button press;
 a long button press.
 The actuator may be operable to receive a control input of a first kind to indicate a first type of input; and a control input of a second kind to indicate a second type of input.
 In the preferred form the actuator is a button capable of rotary and reciprocating motion wherein rotary motion of the button provides a two dimensional control input and the reciprocating motion provides the one dimensional control input.
 A second aspect the present invention provides a method of timing a plurality of events that overlap in time using a common time keeping device, the method including, for each event:
 determining a start of the event;
 determining an elapsed time since the start of the event, and
 in the case that the that the elapsed time is greater than a maximum expected duration of the event, subtracting a start interval from the elapsed time of the event, said start interval representing a time interval between the start of the event and a start of a preceding event.
 The step of determining a start of the event can include deeming that the event starts at a scheduled time that is offset from the start time of a previous event by a predefined starting interval.
 The method can include, determining an end of the event and determining the duration of the event as the elapsed time of the event at the end of the event.
 The method can further include determining a maximum expected duration of the event on the basis of a recorded duration of a first event in the plurality of events.
 The maximum expected duration of the event is preferably calculated according to:
maximum expected duration = duration of first event + start interval 2 ##EQU00001##
 The step of determining a start of each event, can include triggering the start each event. In this case the method can include signalling the start of the event to external device or a user. The time of signalling may be offset from the triggering time.
 The start of an event can be either the time or triggering or time of signalling.
 Preferably the method is performed in a portable timing device. For example the method can be performed using a stopwatch or suitably programmed device.
 The method can include signalling a duration of an event to an external device or user. The signalled duration can be represented as an offset relative to a base time. The base time can be, for example a multiple of 10 seconds or a minute, a target time, a record time or the like.
 In a third aspect the present invention provides a method in a timing system for timing an incident, the method including:
 starting timing upon the occurrence of an event;
 detecting a plurality of inputs to the timing device, indicating a corresponding plurality of time measurements;
 analysing the plurality of inputs to determine the incident being timed.
 The incident being timed can be an aspect of a sporting pursuit.
 The method can include, generating an output based on the time measurements, in a format selected on the basis of the determined incident being timed.
 The method can include, determining a number of timing events in said plurality of timing events; determining a period between at least a pair of adjacent said time measurements.
 In the case that the period between at least a pair of adjacent said time measurements is less than a predetermined threshold, determining that a first incident is being timed.
 In this case the method can include: determining that the incident being timed is a unitary motion or continuous series of motions performed by a participant in a sporting pursuit. For example the repeated motion may be a stroke, stride, movement or the like.
 In this case the output generated can include a rate of performance of the motion.
 In the case that the period between at least a pair of adjacent said time measurements is greater than a predetermined threshold, determining that a second incident is being timed.
 In this case the method can include determining that the incident being timed is a whole event or repeated subset thereof. For example the whole event may be a race, or lap or the like, whereas the repeated subset thereof could be a portion of a lap or other extended interval.
 In this case the output generated can include a time for the completion of the aspect of the event being timed or speed during the subsets thereof.
 In some cases the method can include determining that a certain one of a plurality of aspects of the sporting pursuits is being timed in the event that the period between at pairs of adjacent time measurements falls in a corresponding predefined duration window.
 In this case the method can include determining that the aspect of the sporting event being timed is a portion of an event. For example the one lap of a multi-lap event, periods within a single lap in a single or multi-lap event, or certain predefined sections within a longer event.
 In this case the output generated can include a time for the completion of the aspect of the event being timed or speed during the subsets thereof, or a comparative performance between at least a plurality of the portions of the event.
 In these examples an average time between all or some neighbouring pairs of time measurements can be compared to the thresholds or duration windows. Although timing and outputs can be provided on a period-by-period basis.
 The method can include determining a type of input amongst a plurality of types of input. The plurality of inputs can be of the same type. Alternatively one of the inputs may be of a second type.
 In a fourth aspect the present invention provides a method in a timing system for timing an aspect of a sporting pursuit, the method including:
 starting timing upon the occurrence of an event;
 detecting a plurality of inputs to the timing device, indicating a corresponding plurality of time measurements, each input representing an instant at which a participant in the sporting pursuit meets a predetermined position along a course; and
 on the basis of the plurality of inputs determining a speed of the participant between pairs of said positions along the course.
 The predetermined positions along the course may be spaced equally or un-equally along the course (or on part of the course).
 The method can include displaying the speed of the participant between a plurality of pairs of positions along the course simultaneously on an interface of the timing system. The display can be alphanumeric and/or graphical.
 In a fifth aspect the present invention provides a method of determining a timing of an incident using a timing device operated by a human operator, the method including:
 receiving at the timing device a first input indicating the occurrence of the event; determining a time of said input; and
 determining a corrected first input time by correcting the determined time of the first input to account for a delay in reaction of the operator to the occurrence of the incident.
 Preferably the incident occurs at a time unknown to the operator of the timing device and without visual, or other warning, as to the precise time of the incident.
 The method can include determining an elapsed time between two incident, e.g. the start and end of a race, in this case the method can include receiving at the timing device a second input indicating the occurrence of the second incident and determining a time of said second input.
 In the event the operator of the timing device can estimate the occurrence of the second incident, the method can include determining elapsed time between two incidents on the basis of the corrected first input time and the determined time of the second input.
 The step of correcting the determined time of the first input to account for a delay in reaction of the operator to the occurrence of the incident can include:
 determining the corrected first input time to be earlier than the first input time by a correction factor representing the operator's reaction time.
 In a sixth aspect the present invention also provides a method of determining a delay in reaction of an operator of a timing device. The method may be used for the method of the fifth aspect of the invention. The method includes:
 (a) Indicating to an operator of a timing device an occurrence of an event;
 (b) Receiving an input from the operator, wherein said input signifies the operator's perception of the occurrence of the incident;
 (c) Determining an operator delay on the basis of the difference between the time of receipt of the input from the operator and the time of occurrence of the incident.
 The method can be repeated and an average delay determined for the operator.
 The method can further include:
 receiving an input initiating the determination of the delay;
 waiting a period of time, that is unknown to the operator of the timing device prior to performing step (a).
 If the method is repeated to determine an average delay the method can include waiting a time unknown to the operator of the timing device prior to performing step (a) each time step (a) is to be performed.
 The step of indicating to an operator of a timing device an occurrence of an incident can include, one or more of:
 indicating the occurrence of an incident visually;
 indicating the occurrence of an incident audibly;
 indicating the occurrence of an incident with another device, such that a time of occurrence of the incident, can be correlated with a time kept by the timing device.
 In a seventh aspect of the present invention there is provided a communication device, the communication device including a processing system, the processing system including:
 a plurality of first inputs for receiving a plurality of signals, each signal corresponding to received electromagnetic signal from a respective one of a plurality of electromagnetic transducers, said transducers being spaced from each other in a spatial arrangement;
 a second input for receiving measured information from which at least one spatial characteristic of at least one of said transducers may be determined;
 an output for transmitting an output signal encoding audio data;
 wherein the processing system is configured to derive the output signal from a selected subset of the received signals, wherein the selected subset of received signals is selected on the basis of said at least one spatial characteristic determined from the measured information from the second input.
 In one embodiment, the selected subset of received signals consists of the received signal from specific one of the antennas.
 In one embodiment, the second input is connected to a first orientation measuring device for providing said measured information. The first orientation device is, in one embodiment, a magnetometer. In another embodiment, the first orientation device is an accelerometer that measures a change in orientation.
 Preferably, the measured information represents an orientation of the spatial arrangement of the transducers, as a whole, relative to a frame of reference. In this case, the at least one spatial characteristic that is determined from the measured information indicates which subset of transducers is in a predefined position with respect to the frame of reference.
 In another embodiment, the second input is connected to a plurality of orientation measurement devices. The plurality of orientation measurement devices can include multiple orientation measurement devices of the same type or orientation devices of different types, e.g. magnetometers and/or accelerometers.
 In one embodiment, the orientation of each electromagnetic transducer of the plurality of electromagnetic transducers, or within a sub-group of the plurality of electromagnetic transducers, is determined independently from the other electromagnetic transducers.
 In one embodiment, the communication device includes a switch for coupling only the selected input signal subset towards the output. In one embodiment, the switch is a multiplexor.
 In one embodiment, each of the plurality of signals received at the first inputs include an information signal modulated on a carrier signal, and the output signal is an information signal modulated on a carrier signal which is a subset of the plurality of signals received at the first inputs. In these cases, the system preferably includes a demodulator, the demodulator being configured to demodulate the output signal.
 In an alternative embodiment, each of the plurality of signals received at the first inputs include an information signal demodulated from an electromagnetic signal received at a corresponding electromagnetic transducer and the output signal is an information signal derived from a subset of the plurality of signals received at the first inputs. In this case, the system includes a plurality of demodulators to demodulate the plurality of the received electromagnetic signals.
 In one embodiment, the (or each) demodulated signal is an electrical audio signal. In one embodiment, the system further includes at least one transducer for generating a sound wave from the electrical audio signal, the sound wave being transmitted to the person.
 The communication device may be further configured to transmit at least one electromagnetic signal, the at least one electromagnetic signal being transmitted by a selected subset of the electromagnetic transducers, wherein the processing system is configured to select the subset of the electromagnetic transducers based on said at least one spatial characteristic determined from the measured information from the second input.
 The communication device may further include a transceiver, the transceiver including the demodulator and, additionally, a modulator for modulating data with a carrier frequency for transmission by a selected subset of the electromagnetic transducers.
 In a eighth aspect of the present invention, there is provided communication device which includes a processing system, the processing system including:
 a plurality of electromagnetic transducers, each electromagnetic transducer being configurable to transmit a respective electromagnetic signal, said electromagnetic transducers being spaced from each other in a spatial arrangement;
 an input for receiving measured information from which at least one spatial characteristic of at least one electromagnetic transducer may be determined;
 wherein the processing system is configured to select a subset of electromagnetic transducers from the plurality of electromagnetic transducers, and transmit only on the selected subset of electromagnetic transducers, wherein the selected subset is selected on the basis of said at least one spatial characteristic determined from the measured information from the input.
 Preferably at least one of electromagnetic transducers is an antenna. In one embodiment, all of the electromagnetic transducers are antennas.
 As will be appreciated, the various optional and preferred features of the seventh aspect of the present invention, described in connection with receiving signals above, can be adapted to embodiments of this aspect of the present invention, in relation to transmission of signals, mutatis mutandis.
 For example, in one embodiment of the communication device of the eighth aspect of the invention, the selected subset consists of a specific one electromagnetic transducer. The second input may be connected to a first orientation measuring device for providing said measured information. The measured information may represent an orientation of the spatial arrangement of the transducers, as a whole, relative to a frame of reference, wherein the at least one spatial characteristic that is determined from the measured information indicates which subset of transducers is in a predefined position with respect to the frame of reference. The second input may be connected to a plurality of orientation measurement devices. In one embodiment, the orientation of each electromagnetic transducer of the plurality of electromagnetic transducers, or within a sub-group of the plurality of electromagnetic transducers, is determined independently from the other electromagnetic transducers.
 The communication device of the seventh and/or eighth aspects of the invention may be incorporated into an item that is wearable on a person. The communication device, or at least the electromagnetic transducers may be mounted to, or incorporated into, a body of material. Each of the plurality of electromagnetic transducers may incorporated in respective predetermined locations in the body of material.
 In an advantageous embodiment, the item is wearable on a person's head. Preferably the electromagnetic transducers are, spatially arranged in the material such that there are at least two antennas on opposing sides of the item, wherein when the item is worn, the antennas are on opposites sides of the person's head.
 In one embodiment, the item is formed into a sheet-like member. Preferably the item is sufficiently thin that it can be worn under a swimming cap. In another embodiment, the item is a swimming cap.
 In a ninth aspect of the present invention, there is provided a communication system. The communication system includes a first communication device in accordance with any of the above aspects of the invention, and a second communication device for wirelessly communicating with the first communication device.
 The second communication device may incorporate at least one audio transducer for generating audio signals, at least one electromagnetic transducer (such as an antenna) for transmitting and/or receiving electromagnetic signals for the wireless communication, a microphone for receiving audio data, and a processor for conditioning the audio data for said transmitting.
 In sports training a beep test is used as a form of a fitness stress test. The results of the test can be used to evaluate fitness, as in the case of a VO2Max test.
 In a tenth aspect of the present invention there is provided a method of administering a beep test to a plurality of athletes, wherein for each athlete administering the beep test comprises signalling a cycle time available to an athlete to complete an iteration of an event, wherein the cycle time is repeated with a successively reduced duration for corresponding iterations of the event, the method comprising:
 monitoring a cycle time for a first iteration of the event for each athlete beginning at their respective start time, wherein the start times are staggered by a predetermined time interval;
 signalling the end of the cycle time for the first iteration of the event for each athlete;
 monitoring a cycle time for a further iteration of the event for each athlete; and
 signalling the end of the cycle time for the further iteration of the event, said cycle time being reduced from the cycle time of the preceding iteration of the event.
 In one embodiment, the signalling is the same signal, for example each signal, or beep, has same pitch and volume or visual indicator. However, in one embodiment, the method includes signalling an additional signal for the first signal of each iteration. The additional signal can be a warning sound, visual cue, a word or a phrase that the next iteration is about to start. In this case the additional signal can be signalled just before the commencement of the iteration. In another embodiment, the step of signalling the end of a cycle time for the first and subsequent iterations includes signalling a first type of signal for the first signal of the iteration and at least one further type of signal for the additional signals of the iteration. Because the first signal is a uniquely sounding signal compares with the other signals of the iteration, the athletes are able to identify when the iteration ends, which is also the start of the next iteration. Thus, the athletes can "re-synchronise" to the iteration ends, by counting the number of signals after the first signal to thereby determine when their own iteration ends. Optionally, each signal in an iteration may be uniquely identifiable so that an athlete does not need to count to determine which signal corresponds to their own iteration.
 In a preferred embodiment of the invention, the method includes determining a maximum number of staggered start times within the predetermined interval. The maximum number of staggered start times dictates the maximum number of athletes that can perform at least the first iteration of the event in series, eg as may be the case in a single lane, without colliding with each other, provided that each athlete completes their iteration of the event within a time period that is between a maximum and minimum allowable split time.
 It an eleventh aspect of the invention to provide a timing advice that is adapted to perform any of the methods of the invention. Such a timing device comprising: a time keeping mechanism; an interface for indicating and/or transmitting timing data; and an actuator operable by a user to input timing controls into the timing device, wherein the timing device is configured to perform a method in accordance with any one of the preceding claims. Such a timing device as described in reference to this or any other aspect of the invention is in one embodiment a stopwatch. However, the timing device may be any suitably programmed device, such as a smart phone or tablet. It is therefore appreciated that it is another aspect of the invention to provide software or a computer executable code which when executed by a programmable device, configures the programmable device in accordance with an aspect of the invention.
 As used herein, except where the context requires otherwise, the term "comprise" and variations of the term, such as "comprising", "comprises" and "comprised", are not intended to exclude further additives, components, integers or steps.
 Further aspects of the present invention and further embodiments of the aspects described in the preceding paragraphs will become apparent from the following description, given by way of example and with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
 Embodiments of the various aspects of the present invention will now be described, by way of non limiting example, with reference to the accompanying drawings. In the drawings:
 FIG. 1 illustrates a timing system in which aspects of the present invention may be implemented;
 FIG. 2 illustrates a timing device according to an embodiment of the present invention;
 FIG. 3 is a block diagram illustrating key functional components of the timing device of FIG. 1;
 FIG. 4 illustrates a process used to differentiate between types of user input made with the device of FIG. 1;
 FIG. 5 is a flow chart illustrating a process for timing a plurality of events that overlap in time using a common time keeping device;
 FIGS. 6A and 6B are timelines illustrating a series of overlapping events to be timed;
 FIG. 6C is a timing diagram for a mode of operation of a timing device that is in accordance with an aspect of the present invention;
 FIG. 7 is a flow chart illustrating a method for detecting a type of incident being timed;
 FIG. 8 is a flow chart illustrating a process for computing velocity in a plurality of segments of sporting pursuit;
 FIG. 9 illustrates two ways of segmenting a sporting pursuit, which may be timed using the method of FIG. 8;
 FIG. 10 illustrates an interface displaying several parameters which can be simultaneously collected using an embodiment of the present invention;
 FIG. 11 is a flow chart illustrating a process for determining the user reflex time, which may be used in embodiments of the present invention;
 FIG. 12 is a block diagram illustrating a device in accordance with an embodiment of the seventh and/or eighth aspects of the invention;
 FIG. 13 shows a block diagram of a device, in accordance with an embodiment of the seventh and/or eighth aspects of the invention, representing the primary functional blocks of the device;
 FIG. 14 shows a device in accordance with an embodiment of the seventh and/or eighth aspects of the invention incorporated into an item worn on a person's head;
 FIG. 14A shows a device in accordance with another embodiment of the seventh and/or eighth aspects of the invention incorporated into an item worn on a person's head;
 FIG. 15A shows the person of FIG. 13, wearing the item, and being face down in a body of water;
 FIG. 15B shows the person, as in FIG. 15A, but face up in the body of water; and
 FIG. 16A shows of a second communication device which, used in conjunction with a communication device in accordance with the seventh and/or eighth aspects of the invention, forms a communication system in accordance with the ninth aspect of the invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
 FIG. 1 illustrates a timing system 100, which can be used for timing an incident. Generally speaking, the incident to be timed can be a natural occurrence or an occurrence caused or performed by a person. In the illustrative embodiments the incidents of interest will be aspects of a sporting pursuit or event. The system 100 includes a time keeping device 102 which is used by a time keeper in order to record and track times of events and, optionally to control the operation of the other components of the system 100. The system additionally includes:
 a display in the form of a digital display 104, for displaying the time of one or more current events being timed, or results of previous events that have been timed;
 an audio communication module 106 for providing audio output relating to the event;
 one or more timing input devices such as touch pads 108 which can be used to provide timing inputs to the timekeeping device 102;
 a plurality of athlete units 110A, 110B and 110C, which are worn by respective athletes during the event.
 In the system 100 the time keeping device 102 used by a time keeper to record times for athletes either individually or in groups when completing certain aspects of a sporting pursuit. The time keeping device is used largely in a manner of a conventional stopwatch. However, from the description which follows it will become apparent that the time keeping device 102 has additional capabilities beyond that of a conventional stopwatch. The time keeping device 102 is configured to enable communications between the time keeping device 102 and the external devices 104, 106, 110(A,B,C) and 108. For example, the time keeping device 102 may communicate the current elapsed time of an event being timed, or previous results to a display 104. The display 104 may take the form of a digital read out, scoreboard, televisional or computer monitor, or other like visual display device. The time keeping device 102 can also interface with an audio output device 106 such as a speaker. The speaker may optionally be included on the time keeping device, for example on a rear side (not shown) of the timing device 102. The time keeping device 102 is configured to transmit pre recorded audio signals such as warnings or instructions to athletes, starting signals and other messages used to convey either timing or other information to the athletes or other participants in a sporting event. Additionally, the time keeping device 102 may include a microphone and transmitter such that sounds received at the microphone are reproduced in the manner of a public address system via the speaker 106. The time keeping device 102 is also configured to communicate with a plurality of athlete units 110A to 110C. The athlete units 110A to 110C are worn by an athlete and used to provide instructions and data to the athlete during performance of their sporting event. This information can be in the form of pre recorded information, instructions or the like from the time keeping unit 102 or in the form of audio received by microphone in the time keeping unit 102. Additionally, timing data may be reproduced in audio form and played to the athlete using their athlete unit 110A to 110C. In the present example, the timing system 100 additionally includes touch pads 108. The time keeping device 102 is configured to communicate with the touch pads 108 to receive control inputs. For example, the touch pads 108 may indicate when a sporting event has come to an end or a lap has been completed or other milestones achieved.
 The time keeping unit 102 is arranged to communicate via a wireless communications channel with each of the other elements in the timing system 100. However, in certain embodiments, one or more of the communications channels may be via a fixed line communication channel such as fibre optic link, Ethernet or other wired communications medium.
 Turning now to FIG. 2 which illustrates the time keeping device 102 in greater detail. As can be seen, the time keeping device 102 has general form of a conventional stopwatch. The device is sized such that it is able to be hand held in a single hand by most adults. The time keeping unit 102 includes an external housing 200 which holds the various components of the unit 102. Mounted on the housing 200 is a display 202 providing a visual indication of operation of the device to its user. Primary control of the device is performed using a pair of input control buttons 204 and 206. The control buttons 204 and 206 are configured such that a user can provide different types of inputs using each of the buttons 204 and 206. For example, each of the buttons 204 and 206 is connected to an actuator which can receive, and distinguish between, user inputs of different kinds. In this example, the actuator is adapted to receive a pressing input on the top of the buttons 204 and 206 and also receive rotary inputs by the user rotating buttons 204 and 206. The time keeping unit 102 also includes a pair of switches 208 and 210. In one form the switches are push to talk buttons which activate a transmitter circuit for transmitting audio to respective athletes (or groups of athletes) wearing athlete units such as units 110A to 110C. In order to receive audio signals from the user, the unit 102 is also provided with a microphone 212. The device 102 may additionally include a loud speaker for playing sounds to the user of the device and the surrounds of the device. The time keeping device 102 also includes an audio output jack 214 enabling the user to connect headphones or an external audio system to the device. A charging port and/or data input/output is also provided at port 216. In order to indicate correct operation of the charging of the device 102 a charging indicator light 218 is provided. Operational indicators 224 and 226 are also provided adjacent the user controls 204 and 26 to provide the user with feedback on the operation of the device
 The time keeping device 102 is arranged such that it can be used to independently time two events or groups of events, and independently communicate with and/or control timing systems relating to two athletes or groups of athletes. In order to enable this, the time keeping device 102 duplicates certain of its functionality. In this regard, each of the user controls 204 and 206 may be used independently of each other and in the same way to independently control timing of separate events. In their rotational mode of operation one of the buttons 204 or 206 can be assigned to perform the same or different tasks. In one example one of the buttons 204 or 206 is assigned as "Select" dial that is used to select parameters applied to the device whilst operating in a specific mode, whereas the other can be assigned to as a "Mode" selection dial operable to select the timing mode in which the unit is operating. In a preferred form one of the switches 208 and 210 is used to enable the user of the time keeping device 102 to communicate with different athletes or groups of athletes, for example by assigning the switch as a "push to talk" switch. The other of the switches 208 and 210 is assigned to operate as an interlock button to safeguard against erroneous operation of other controls. In order to prevent unintended rotational motion of the control buttons 204 and 206, e.g. accidentally at any time or during a pressing motion, and the consequential unintended control input to the timekeeping device 102, control switch 210 is programmed to operate as an interlock for at least the rotational input mode of the buttons 204 and 206. In order for the rotary encoders of the control buttons 204 or 206 to be active, the operator needs to depress switch 210 whilst the rotational input is made.
 The push to talk switch 208 is able to be dynamically assigned to one or more desired parties to allow communication with them using the rotational input on one of the control buttons 204 or 206. To achieve this, whilst the "talk" button 208 is depressed the button 204 (or 206) is rotated to select the receiving party. The device 102 can be programmed to communicate to up to 32 different subsets of possible receivers (including all receivers) forming part of the system 100. For example by rotating the encoder of button 204 when the talk button is pressed the user can select the correct receiver to enable the user to communicate with speakers or other audio output or storage devices, coaches, individual athletes, one or more defined groups of athletes etc.
 The display interface 202 is also a multi coloured display and the system is arranged such that data relating to different athletes or groups of athletes can be displayed in different colours such that they can be distinguished. As will be appreciated, the ability to independently time multiple events may be of great utility in a coaching environment where multiple athletes share a coach or athletes are grouped into multiple squads to be coached simultaneously. By using a timing device such as that described in FIG. 2, the coach can keep track of times in respect of performance of separate groups of athletes with a single device.
 FIG. 3 illustrates a functional block diagram illustrating the key components that enable operation of the time keeping device 102. All operation of the time keeping device 102 is performed by a suitably controlled micro controller unit 302. A first type of input to the micro control unit 302 comes from the user control interface 304 in the form of push buttons and rotary encoders connected to buttons 204, 206 and the buttons 208 and 210. Communications with external systems are performed using the external input/output port 306 and via a radio communications sub system 308. The radio communications sub system 308 includes a transceiver 310 and an associated antenna 312. Visual outputs from the device are performed by a display 314 and audio outputs via the audio input/output system 316. The audio input/output system 316 includes one or more audio codecs and an amplifier which outputs audio via speaker headphones or microphone or other audio transceiver 320. In addition to the memory used to store programs for controlling the operation of the micro controller unit 302, the system 300 can additional include flash memory 322 for long term storage of timing and other data. The system 300 additionally includes a real time clock 324 for generating and enabling display of time of day information to the user. Power for the system is provided via a battery 326 which provides operational power to all onboard systems. However, the real time clock 324 may additionally have a backup battery 328 which is used to supply power to the clock 324 in the event that the battery supply 326 goes flat. This enables the real time clock 324 to keep correct time and track any ongoing milestones such as alarms and the like.
 Because the system 300 is operated by a program or micro controller unit, or other suitable processing hardware and the actuators associated with the system is able to be programmed to distinguish more than one type of user input from the user controls, particularly buttons 204, 206. The preferred embodiment can distinguish between three different user input actions or sequences using a single input type, which opens a range of control possibilities for the timing device 102. Moreover, the use of a combination of input types in the user controls can provide a user friendly way to provide additional inputs to the system. In one form, the different types input actions or sequences are used to indicate timing events whereas different input types are used to select a mode of operation, or mode of timing, or parameters of the event being timed.
 In one example the timing device 102 is programmed to differentiate control inputs on the basis of a temporal sequence of inputs or temporal property of an input action. In this regard, control input of any switch on the device, but most commonly the main user input controls 204, 206, the system can differentiate between the following user interactions to recognise them as different control inputs:
 A single, short press: this input is a button press typically less than 400 milliseconds in duration. The timing event is defined as having occurred at the start of the button press. However, recognition of this timing event only occurs on release of the button, indicating that the button press was in fact a short, single button press.
 A long press: a long press is typically more than 400 milliseconds in duration. The timing event for the long press is taken to be the initiation of the pressing action. As for the short press, recognition of the long press occurs upon release of the button.
 Double press: this is a pair of short presses within a preset time period. For example, the time period may be 600 milliseconds. This event is recognised by the system on release of the button after the second pressing action is performed.
 Clearly triple presses and combinations of long and short presses could also be defined. However, the subset described herein is sufficient for many purposes. To illustrate this point, a system configured to differentiate between short, long and double press inputs of a single button is able to be used for start/stop/split/undo and reset functions, whereas a conventional stopwatch would require multiple buttons or a complex mode selection system to provide this functionality. For example, in use, a short press on the button causes a reset of a corresponding timer to 0 (or a preset reflex compensation value, as will be described below) and starts the timer. At each milestone the user of the timekeeping device 102 can perform a short press of the button to record split times. At the end of the event, a long press on the button can stop the timer to enable display of the cumulative and split times. In the event that a split time is indicated in an error, the user can "undo" this using a double click input. Receipt of a double-click after a split milestone causes the time keeping device 102 to delete the last recorded milestone while subsequent short, single clicks will indicate the next correct split time.
 As can be seen from this brief description, a distinction between single short, single long and double press on one button, a time keeping device 102 such as that illustrated in FIG. 2 can be used to independently time two events by virtue of these two buttons and appropriate software and/or circuitry configured to operate two timers. Furthermore, as will also be appreciated, it is possible that the use of additional buttons would allow timing of more than two distinct events, or more than two athletes competing against each other in the same event.
 FIG. 4 illustrates a process 400 that is used in an embodiment to distinguish one type of user interaction with a timekeeping device from another interaction with the same control button. The process begins at 402 by the user pressing a button of the timekeeping device. On the occurrence of the button press 402 an initial time stamp is recorded at 404 and the timer is begun at 406. To provide feedback to the user that the button press has been recognised a button sound is generated by an audio output device. Next, the system monitors for release of the button at step 410. If no button release is detected, the system remains in a state waiting for button release. Upon release of the button, the duration of the button press is analysed. Initially, at step 412, the button press duration is compared to a first threshold and in the event that the button press is longer than the first threshold, the button press is deemed to be a long button press in step 414. In the event that the press button duration is shorter than the first threshold, the button press duration is compared to a second button press threshold in step 416. The second button press threshold used in step 416 is shorter than the threshold used in step 412 and if the button press duration is greater than the short press duration, the user interaction is deemed to be a short press at step 418. If the user interaction is shorter than the short press duration, the press is deemed to be invalid or possibly part of a user input which comprises a plurality of discrete user input interactions such as a double press.
 In addition to this temporal distinction between user interactions with a control each of the buttons 204 and 206 are configured such that they can receive an input of a first type, being a rotational input, and an input of a second type, being a reciprocating or pressing input. In the examples given below, the pressing inputs are generally used to control the recording of timekeeping events by the timekeeping device. In contrast to this, the rotational inputs are able to be used to indicate other types of input to the timekeeping device, such as a mode selection input or a scrolling input for a graphical user interface of the device. Several different timing modes into which the timing device can be put, and their operations will now be described. It should be noted that the timing methods to be described hereafter should not be considered as being limited to the form of timekeeping device described above. On the contrary those skilled in the art could determine how to implement one or more of these timekeeping methods be implemented on handheld timekeeping devices with substantially conventional input controls, or on other devices and systems which could be used for recording times of occurrences. Moreover, the methods described herein could be implemented in application software running on a computing device, such as a personal computer, tablet computer or mobile handheld computing device such as a smart phone, PDA, or the like.
Timing Intervals for Multiple Overlapping Events
 In some instances it may be necessary for a sports coach to time the training performance of a squad containing multiple athletes. Typically, this is done by having individual members of the squad perform their training routine, such as a swimming a lap of a pool running a standard course etc, individually. Since the squad of athletes will be selected such that they are likely to record similar times for this routine, more efficient squad training can be achieved by staggering the start time of each individual with a set spacing between them, rather than having the athletes take turns. This allows more training to be performed in a set amount of coaching time. FIG. 5 illustrates the process which can be used by a timing device to assist a coach in recording and providing athlete feedback in this type of squad training environment. FIGS. 6A and 6B illustrate timing diagrams showing starting times 600 and finishing times 602 for a squad of athletes. Turning firstly to FIG. 6A, the squad has eight athletes, each beginning their routine twenty seconds apart. Accordingly, start times range from time 00:00:00 through to time 2:20:00. Each athlete is expected to take approximately thirty seconds to complete their lap, and accordingly end times are between thirty seconds and three minutes. This situation is replicated in FIG. 6B. The difference being that in FIG. 6B the fourth athlete to begin training, ie the athlete leaving at time 1:20:00 does not complete their lap for some reason.
 Returning now to FIG. 5 which shows a mechanism by which the system of FIG. 1 and the timekeeping device therein can be used to time this group of athletes in a manner that is straightforward for the timekeeper. The method 500 of FIG. 5 begins by the user of the timekeeping device giving a start input to the timing device 102. The start input may be in the form of pressing a button 204. In the process 500, the timing device controls not only the recording of the time for the event but also starting the event and notifying each successive athlete in the squad when to begin their lap. Once the start input is entered at 502, the system goes into a short delay in step 504, and then emits a warning signal at 506. The warning signal in step 506 is played to the squad members to alert them that the training event will begin shortly. After this first warning signal at 506 (e.g. a beep), a delay of one second is introduced at 508 followed by a second warning signal at 510. This step is followed by a further one second delay at 512 and a final warning signal at 514 which is then followed, either immediately or after a further one second delay (not shown), by a start signal at 516. As it will be appreciated, the period between the first warning signal at 506 through to the final warning signal at 514 is effectively a countdown to the beginning of the event to warn the first athlete of its impending start. Once the start signal at 516 is sent the timer corresponding to the button which was pressed to indicate the start input 502 is begun at step 518. This system can continue issuing start signals at fixed intervals to indicate to successive athletes when they should begin their lap. Alternatively, the athletes may know the interval time and begin at the correct time of their own volition. Typically training environments will include one or more easily visible timing devices such as a lap clock or digital read out (eg digital read out 104 of FIG. 1) to make this practical.
 In other embodiments the countdown delays and beeps run as a separate program task that is executed from a main program when the countdown is required. For example, in one embodiment (not shown) the start input 102 directly triggers the start signal 516. The start signal 516 then triggers both the start timer and the countdown timer to run in parallel.
 Each time an athlete reaches the end of their lap, the coach presses a button on the timing device to indicate that a split time for the athlete should be recorded. Accordingly, some time after the beginning of the training session, the timekeeper will make an input into the timing device. When this occurs the method of 520 determines the form of that input. In the event that the input is a split input an analysis is made of the split input in sub process 522 to determine the correct split time for the athlete. Alternatively, if the input is a stop input as determined at step 524 the timing event is stopped entirely and the timing device returns to its initial state. In the case where the input is neither a split input nor a stop input the input is rejected, or may be acted upon in a different way. Returning now to the case of measuring split times at subprocess 522 in an initial step a decision is made at 526 whether the split being recorded is the first split of the timekeeping event. If the split being recorded is the first split, a split time is saved as a reference split value in 528. The reference split value will be used as a guide in the remainder of the process to determine whether subsequent split times are valid times or not. On the basis of the reference split time recorded at 528, a minimum acceptable split time is determined at 530 and a maximum acceptable split time is determined at 532. The minimum and maximum acceptable split times can be determined either on the basis of a fraction of the reference split time itself, or most preferably on the basis of a the interval time between athletes. For example, the minimum acceptable split time may be calculated as reference split time minus half of the interval time. Similarly the maximum acceptable split time is calculated either on the basis of the split time itself or some other factor such as the interval time. In this example, the maximum acceptable split time is calculated as the reference split time plus half of the interval between athletes. Allowing the boundaries of acceptable split time to vary from the reference split by half of the interval time should allow sufficient leeway to encompass all athletes in the squad, if the squad is selected to have a reasonably even skill level, and in the event that the reference split time is of an athlete who operates close to the average split time, it is likely that the acceptable split interval (between the maximum and minimum acceptable split times) would allow the slowest and fastest athletes to operate successively without colliding in their timing.
 For all split events input into the system after the first, the recorded split time is compared in step 534 with the maximum acceptable split time and with the minimum acceptable split time at 536. In the event that the recorded split time is greater than the maximum acceptable split time in step 538 the interval time is subtracted from the split time and the comparison of step 534 is performed again. This loop of comparing the split time with the maximum acceptable split time is repeated until the split time is less than the maximum acceptable split time. The split time after passing step 534 goes to the minimum acceptable split time comparison in 536, and in the event that the split time is in an acceptable band between the minimum acceptable split time and the maximum acceptable split time, the split time is saved in step 540. An indication that the split has been recorded is given in step 542 e.g. by beeping. The system then goes into a stage of awaiting the next timekeeper input into the timekeeping device.
 The loop between steps 534 and 538 functions to decrement the elapsed time by increments equal to the interval time until the current split time is a time beneath the maximum acceptable split time and therefore may constitute a valid split time for an athlete having begun on one of the appropriate interval time points. This time is checked against the minimum acceptable split time in step 536 for validity. The validity check in step 536 will typically serve to determine whether a decremented split arriving from step 534 has been correctly decremented or is actually a split time which is slightly greater than the maximum acceptable split and which has consequently been decremented by one too many interval periods. In the embodiment shown in FIG. 5, if the split time is less than the minimum acceptable split time, the split time is ignored, as indicated at 537.
 FIG. 6A also illustrates an output of the process of FIG. 5 for the eight athletes illustrated in FIG. 6A. In FIG. 6A athletes one through eight leave at twenty second intervals at the times marked in column 600. Their arrival times are indicated in column 602. The first athlete leaves at time 00:00:00 and arrives at 00:30:00. The displayed split time is 00:30:00 as this is the first split recorded. Additionally, as this is the first split recorded, thirty seconds is stored as the reference split time. Any split times which subsequently are received which lie between twenty and forty seconds, that is thirty seconds plus or minus ten seconds, where ten seconds is half of the twenty second interval defining the athletes start times. The second athlete leaves at 00:20:00 and completes their event at an elapsed time of 00:52:00. The split time of 00:52:00 was compared to the maximum acceptable split time of 00:40:00 and rejected as being too high. Accordingly, the 00:52:00 interval time is decremented by the 00:20:00 interval, resulting in a new split time of 00:32:00. The 00:32:00 time is compared to the 00:40:00 maximum acceptable split time and 00:20:00 minimum acceptable split time and found to be a valid split time and is displayed as the second athlete's split of 00:32:00. This process is continued for all athletes in the event. As a final illustration, consider the final athlete leaving at 2:20:00. This athlete arrives at the end of the event at an elapsed time of 2:54:00. The recorded split time at 2:54:00 is compared to the maximum acceptable split time and found to be above the maximum acceptable split and decremented by the interval time of 00:20:00. This results in a new split time of 2:34:00. The new split time of 2:34:00 is also compared to the maximum acceptable split time and found to exceed the maximum acceptable split time and, again, the split time is decremented by the interval. This results in a further new split time of 2:14:00. This process of comparing the split time with the maximum acceptable split time is repeated and eventually a split time is returned of 00:34:00. When this is compared to the maximum acceptable split time it is found to be beneath the maximum acceptable split time and above the minimum acceptable split time and therefore recorded as a valid split for the final athlete.
 FIG. 6B illustrates the same event as FIG. 6A however, the athlete leaving at one minute does not complete their turn. In order to understand how this event is handled by the present system consider the athlete leaving at 00:40:00 and arriving at the end of their event at 1:10:00. This 1:10:00 value is compared to the maximum acceptable split time and decremented twice before arriving at an acceptable split time of 00:30:00. The athlete who leaves at 1:00:00 may either stop halfway through the event and not complete the event and therefore not achieve any split time, or reach the end of the event at some distant time at which the coach determines there is no value in the split time being recorded. Accordingly, between the elapsed time of 1:10:00 and 1:51:00, no split time is indicated to the timekeeping device. For the athlete leaving after the missing athlete, ie the athlete leaving at 1:20:00, this athlete arrives at the end of their set at 1:50:00 elapsed time. The 1:50:00 elapsed time is recorded as the initial split time and compared with the maximum acceptable split time of 00:40:00. This split time will then successively get decremented by the interval time as follows:
 1:50:00 is decremented to 1:31:00. 1:31:00 is decremented to 1:11:00. 1:11:00 is decremented to 00:51:00. 00:51:00 is decremented to 00:31:00. Until the split time is recorded at 0:31:00, the current split time is above the maximum acceptable split time value of 00:40:00 and is not recorded as a valid split time. This final valid split time is then presented to the timekeeper as the athlete's time. Accordingly, it can be seen that the absence of the athlete leaving at 1:00:00 does not cause the system to become out of synchronisation with the athletes and erroneously record the split time for the athlete at 1:00:00 of 00:51:00, but to correctly identify the missing athlete and record a split time for the athlete leaving at 1:20:00 of 00:30:00.
 During training sessions, an athlete will often perform a routine comprised of multiple events, and will rest between each event. Each event may be timed as an event in its own right or as a split within a larger event. The rest time can be commenced from the time of completing the first event, but it is often desirable to define a total predetermined time within which the athlete must both complete their event and rest before their commenced their next event. If the athlete completes their event quickly, they will have more time to rest, or conversely, a slower event completion will result in less time to rest. In some cases it is desirable to record split times, for example by using a suitably adapted method as descried herein. However, in other cases the split times are not important. Rather, the important timing consideration is knowing when the athlete should start their next repetition of their event. In the case of multi-athlete training, where each athlete starts their event a fixed interval after a preceding athlete, time keeping device 102 signals their start time as has been described herein, for example by signalling start signals 516 corresponding to respective athletes. Where such training involves multiple a repeated event, time device 102 can be configured to restart sub-process 522 for each repeat of the event, with each restart occurring a predetermined time after the start of the previous sub-process 522. If there is crossover between the completion of one iteration of sub-process 522 and the start of the next sub-process 522, there is potential for event measurements to be attributed to the wrong athlete or split number. Therefore timing device 102 utilises a simplified sub-process in which the maximum number of athletes is predetermined. The user of timing device 102 inputs a Start Interval Time, Cycle Time (ie the time from the start of one event to the start of the next event), and a Set Time (ie the expected time to complete the event).
 With the timing device 102 knowing these parameters, the timing device 102 calculates other parameters according to the following equations:
Maximum no. of Swimmers=1+Integer of [(Cycle Time-Time Margin)/Start Interval Time]
RANGE=Cycle time-((Maximum no. of Swimmers-1)×Start Interval)
Minimum valid split time=Set Time+RANGE/2
Maximum valid split time=Set Time+RANGE/2
For swimming applications, it is typically ideal for the maximum and minimum valid times for a split to be around 5 seconds greater than and less than the Set Time, respectively. In one version of pace training mode, a start signal is sounded for the first swimmer to begin their event.
 The subsequent swimmers can either count the desired interval time before starting their event, or may receive their own start signal, for example via their corresponding athlete unit 110. The timing device 102 then records each split and, after the first split, subtracts the start interval to determine the corresponding split time for subsequent athletes. Once the Cycle Time has elapsed, this process repeats. However, by limiting the number of swimmers in the manner described, it is unnecessary for all swimmers from the first iteration of event to complete their event before starting the second iteration. An example timing diagram 650 for pace made is illustrated in FIG. 6C. The timing diagram 650 illustrates the three successive expected event times (in this case lap times) for each of four swimmers. The top row 652 of timing diagram 650 indicates the number of seconds since the start of the first lap (L1) for Swimmer 1. The Set Tithe for the swimmers is, in this example, 30 seconds. Therefore, Swimmer 1 is expected to finish their first lap 30 seconds from the start of their event. The Start Interval Time is 10 seconds, so at the times of 10, 20 and 30 seconds, Swimmers 2, 3 and 4 respectively start their first lap. Thus, Swimmers 2, 3 and 4 are expected to complete their respective lapsed at 40, 50 and 60 seconds respectively.
 The embodiment in FIG. 6C provides a minimum valid time of 20 seconds and a maximum valid time of 30 seconds, so all valid times for lap 1 need to fall between 20 seconds and 60 seconds. However, more typically, for Set Time of 30 second, the Time Margin is 5 seconds, resulting in minimum and maximum valid lap times for a swimmer being between 25 and 30 seconds. For such a Time Margin, all valid times for lap 1 would be between 25 and 65 seconds (not shown). The embodiment in FIG. 6C also works on a Cycle Time of 40 seconds, resulting in Swimmers 1, 2, 3 and 4 starting their second laps at 40, 50, 60 and 70 seconds respectively.
 A variation on the "pace mode" of operation is a "beep test" mode. When training according to a "beep test", an athlete places little or no concern on their split times per se. Rather, they aim to achieve complete as many event iterations as they can over the course of the beep test. The task required of the athlete is to complete their event iteration within the Cycle Time, ie before the next iteration is scheduled to commence. The commencement of each event iteration is indicated by an audible "beep". The Cycle Time is incrementally reduces for each successive iteration, making completion of the event within the Cycle Time harder for each successive iteration. Beep tests as have been commonly used in the past have required each athlete to commence each iteration at the same time. In other words, the athletes must race in parallel. However, by successively reducing the Cycle Time of time keeping device 102, athletes are able to stagger their starting times, by the predetermined Time Margin, as described in relation to the "pace mode". This enables the athletes to race in series, allowing them to share a single lane of a swimming pool/track etc.
 Because the Cycle Time reduces with each iteration of the event, after enough iterations the athletes will eventual bunch up and collide with each other. Therefore in beep test mode, the maximum number of swimmers is calculated depending on the Time Margin, Start Interval and Minimum Cycle Time, the Minimum Cycle Time being the Cycle time at the end of the beep test (eg the last Cycle Time of the beep test). Typically, the Minimum Cycle Time will be set to a Cycle Time in which none of the athletes can complete an iteration of their event, thereby ensuring that all athletes complete the beep test. In Beep Test mode, the timing device 102 calculates other parameters according to the following equations:
Maximum no. of Swimmers=1+Integer of [(Minimum Cycle Time-Time Margin)/Start Interval Time]
RANGE=Cycle time-((Maximum no. of Swimmers-1)×Start Interval)
Minimum valid split time=Set Time-RANGE/2
Maximum valid split time=Set Time+RANGE/2
Incident Type Detection
 In the case where a timekeeper is timing a plurality of different types of incident which may occur within a single larger incident, the process illustrated in FIG. 7 can be used to determine what type of incident is being timed. In one example, in swimming training a coach may decide that it is necessary to determine an athlete's stroke rate whilst they are swimming a lap of a pool. In a conventional setup, the coach would typically require two stopwatches to do this, one to time the lap and the other to time stroke period. Additionally, the stroke rate may need to be manually computed based on the stroke timing recorded. In order to time stroke rate the usual process involves the timekeeper recording split times corresponding to one period of the swimmer's stroke, possibly repeatedly in order to take an average, and then using this to compute how many strokes per minute are being swum. The same goes for a runner's stride, rower's stroke, horse's stride or other repeated incident.
 The method illustrated in FIG. 7 is a method for determining whether a set of inputs into a timing a device represent a series of events recorded for timing one type of incident as opposed to a series of events used to time some other type of incident. For example, distinguishing between inputs intended to calculated stroke rate from inputs intended to calculate lap splits for a swimmer. The process 700 begins by receiving a user input at the start point 702. The input, for example, can be a short press on one of the buttons of the timing device. When this input is received, the input is compared to a nominal threshold representing the number of timing inputs that have been received. In this case, where stroke rate timing is being detected, the method at step 704 determines whether more than three timing inputs have been received. In the event they have not, the process returns to its starting state and waits for the next input. If more than three split time inputs have been received, the split times are compared to a maximum time threshold, which in this stroke rate example for swimming is 3.5 seconds. In the event that the split times are greater than 3.5 seconds, it is determined that the splits do not fit the expected time window for stroke period measurement and that some incident other than a swimmer's stroke is being timed and the measurement process ends. If the time signals are measured at less than the threshold, it is possible that the user inputs being received represent split times for a swimmer's stroke period. In this case, the method moves onto step 708 where the split times are compared to a lower threshold. In this case, a lower threshold of 0.5 seconds is used. In the event that the split time received is lower than the lower threshold it is determined that the user inputs are representing something which is faster than the expected split times for the incident under consideration, i.e. the inputs are determined not to be stroke rate timing points. If the recorded split times are above the lower threshold, it can be determined that the series of split times are of a duration which is a likely duration for the incident being timed, and those split times can be further processed in order to determine a time, average time or other parameters such as rate of performance of the incident. In the case of measuring stroke rate at step 710 this further processing includes a step of determining a total time for the series of splits. This is performed simply by adding these split times to each other. Next, stroke rate is determined by dividing 180 by the total time determined in step 710. The formula in step 712 is adapted for the case in which three splits representing the periods of three separate strokes are recorded, and the output of step 712 in step 714 is displayed as stroke rate in strokes per minute. Obviously, other rate outputs are possible such as strokes per second or the like. As will be appreciated, steps 706 and 708 can be considered together as a subprocess for comparing a series of user inputs to a plurality of criteria, and on the basis of that comparison determining a type of incident being timed by the plurality of user inputs. Similar criteria can be developed for other types of incidents, and it is possible that a determination of which of several types of incident are being timed can be made. For example, this may be on a basis of a number of inputs being received or certain split time bands in which the inputs are made. In the example given in FIG. 7, it may be pointed out that the comparison to the lower bound in step 708 is able to be used to determine the difference between received button pressed one split time measurements or a rapid series of button presses which are together considered to be a single input such as a double press or triple press of the user input button. Moreover because the system can differentiate between different inputs with the same control, e.g. differentiate between a short and long press or the like, the same timekeeping device can also be used to simultaneously time the duration of some longer event, such as a lap. In this regard the first inputs with the user control (e.g. short presses) are used to define the timing points for the rate measurement, whereas the second inputs (e.g. long press) is used to indicate the end of the event being timed, enabling both to be timed simultaneously.
Velocity Computation of Sub-Incidents
 In some situations, it may be advantageous to measure velocity of an object or athlete over part of a sporting event or other event. FIG. 8 illustrates an exemplary method 800 for computing velocity over 4 incidents or subevents forming part of a larger incident or event. In the present example, the subevents one distance intervals that do not have the same length, however examples where the same length intervals are used can also be implemented. Consider, for example FIG. 9, which shows a diagram of two events 900 and 902, which are swimming events in a fifty-metre Olympic pool 904. The first event 900 is a fifty-metre single lap broken into four distance intervals as subevents. The four subevents are an initial fifteen metre section of the pool, a following ten metre length up to the halfway mark in the pool, followed by a ten metre length and a final fifteen metre length. It is customary for this fifteen, ten, ten, fifteen metre interval arrangement to be indicated on lane ropes in Olympic pools and therefore are often used by coaches of swimmers to determine sub lap swimmer performance. Usually, the feedback given by the coach to the swimmer will be the swimmer's time over each of these partial laps.
 The second event indicated at 902 is a two hundred metre swimming event comprised of four laps. It may be useful to determine split time or swimmer's speed over each of the four laps.
 In order to understand why these measurements would be a useful to a swimmer, it may be determined that an athlete is particularly weak or strong in a certain segment of the race and this data can then be used either to inform a training routine to improve on weaknesses or to determine a race-day strategy to exploit the athlete's strong points against their competitors. It can also be used to determine whether the athlete is tiring over time or is not exerting maximum effort throughout a whole training routine.
 In order to compute velocity information over these segments, the timing device is programmed to know the distance in each of the segments of the incident being timed. Next in the method 800 the timekeeper makes an input into the timekeeping device which indicates a start of the event at 802. Next at the completion of the first segment, a further input is provided to the timekeeping device by its user in step 804. This is analysed to determine whether this input indicates the completion of a first split. In the event that it is not, the system returns to a state in which it is waiting for the first split time to be entered. In the event that the input was regarded as the first split input in 804, velocity of the athlete over the first segment can be computed by dividing the pre-entered distance of the first interval by the first split time in step 806. In the meantime, the system awaits an input which is interpreted as the second split time input. When another input is received, it is determined at step 808 whether this input indicates a timing point for the second split. In the event that it is considered to be the second split, the distance between the first split point and second split point is divided by the second split time to arrive at the second interval velocity at 810. In a similar way, the system waits for the third split press and at step 812 if the third split input is received, velocity is calculated at step 814. Similarly in step 816, if a subsequent input is determined to be the fourth split input the velocity can be computed in step 818. In the event that the timekeeping device knows how many subevents constitute the whole event (or a whole lap of the event) in step 820 an event time (or lap time) can be displayed which is the elapsed time between the start press at step 802 and the fourth split press at 816. If the timekeeping device detects a long press either corresponding with the fourth split press 816 or subsequent thereto, timing is ended at 822. Otherwise, the timekeeping device knows that another lap following the same scheme of intervals will be timed and expect split inputs corresponding to each of the segments of the lap to be input again for the next cycle of the event. In this case, the process 800 returns to waiting for the first split input, to begin recording split times and computing velocities at step 804.
 As will be appreciated the example given in FIG. 8 corresponds to an event having four distinct subevents or intervals within it such as four segments along a single lap of a pool, or four segments of a lap within a multi-lap race, or four laps within the multi-lap race. However, there is no limitation on the number of subincidents or subevents for which performance data can be recorded using a method similar to FIG. 8.
 In a timekeeping device such as that illustrated in FIG. 2, which includes a visual display capable of rendering graphics, it can be particularly useful to display a combination of athlete results on a single graphical user interface. FIG. 10 illustrates such an interface. The interface shows an athlete's data over six distinct intervals within an event. These intervals are labelled 1001, 1002, 1003, 1004, 1005, 1006. For each of the six intervals 1001 to 1006 two pieces of data are shown. Firstly, a bar value is illustrated e.g. bar 1008 corresponding to time interval 1001. This bar 1008 may indicate a number of seconds taken to perform the interval. An indicator 1010 is also provided. This indicator 1010 indicates a stroke rate recorded for the athlete over the interval 1001. For each of the intervals shown, 1001 to 1006, a similar bar chart and indicator bar showing elapsed time and stoke rate are illustrated. Combinations of other timed or calculated parameters can also be provided.
 The programmable nature of the device illustrated in FIGS. 2 and 3 also opens possibilities for improving timing accuracy in recording events. One form of inaccuracy which may arise is the operator's reaction time for events which are not able to be anticipated by the operator. An example of such an event would be the start of a race where the timekeeper has no information about the instant at which the race would be started and accordingly the user's activation of the timing device will lag the actual race start by a period equal to their reaction time. A similar lag does not typically exist at the end of a race or when timing split times are recorded because the timekeeper is able to relatively accurately predict the occurrence of the split time or end of a race by watching the approach of the athlete to the milestone or race end point. Accordingly, this error can largely be ignored. Moreover, errors in events that cannot be anticipated will almost always be in the form of a time lag between the actual time of starting and the time at which the user of the timing device indicates starting. The present timekeeping device accordingly can be programmed to address this error by subtracting the user reaction time from the elapsed time to correct this lag.
 In order to determine the reaction time to be subtracted from the elapsed time, the timing device can implement a method of the type indicated in FIG. 11. The method 1100 is a method for testing the reaction time of the timekeeper. In general, it operates by randomly generating a mock start-event and measuring reaction time between the point of occurrence of the mock start-event and the user's timing input indicating the time of that event. Accordingly, the method begins at step 1102 by the user pressing an input to begin the reaction time test. At this point a counter is set at zero in step 1104 and a series of reaction time tests begun. The reaction time testing enters the reaction time measurement loop at 1106 by incrementing the counter by one and then implementing a random delay, say between one and three seconds, at 1108. A starting event is then indicated at 1110. The starting event may be in the form of a beep or flash of an indicator, or some other kind of event which can be sensed by the user being tested. The timing device then waits at step 1112 for a user input into the timing device. When the input is received at step 1114, the delay between the start indication in step 1111 and the time at which the user input is made in 1114 is measured. This process may be iterated several times to gain an average reaction time e.g. in step 115. After a predetermined number or iterations the method is exited at step 1116 and the method ends at 1118. At the end of the method 1100 the user's reaction time over the series of tests performed is stored for later use. In this regard, a correction for the user's average reaction time can be made each time a user makes an input corresponding to an unpredictable event.
 As can be seen, by implementing embodiments of one or more of these aspects of the present invention, entirely new methods of using a timing device can be obtained.
 In one form, this is performed by effectively redefining the way in which a user may provide inputs to the timing device, for example by using rotational and reciprocating motion on the same input actuator and by programming the timing device to differentiate between different types of user physical input and mapping these to different types of control input to the timing device. In the preferred form this allows a single actuator or button to be used by a timekeeper to record events which would conventionally have required multiple separate actuators on a conventional stopwatch. Moreover, by duplicating the multi-purpose actuator in a device, the need for a timekeeper to operate multiple separate timekeeping devices is reduced.
As was described with reference to FIG. 1, system 100 includes athlete units 110(A,B,C), which are worn by respective athletes to allow the time keeping device, or a person operating the time keeping device, to communicate with the athletes. For example, the time keeping device 102 can transmit to a specific athlete by addressing their specific athlete unit, thereby sending the athlete information that that may include, for example, a split time, travel velocity, stroke rate or other recorded measurement; a start and/or warning beeps for that swimmer to commence an event; or a voice signal received by microphone 102.
 An example of such an athlete unit 110(A,B,C) which enables these and other functions is depicted in FIG. 12, and is referred to hereinafter as a communication device 1210. The communication device 1210 includes a central controller 1220 having a processing system 1212. The central controller 1220 is connected, via processing system 1212 and wires 1216a and 1216b, to respective electromagnetic wave transducers which, in the presently described embodiment, are a first antenna 1214a and a second antenna 1214b. The central controller 1220 also includes an orientation measurement device 1218, which is connected to the processing system 1212. The components of the communication device 1210 are powered by a battery 1221. The orientation device 1218 measures data representing a spatial characteristic, and provides this data to the processing system 1212. For example, the output of the measurement device 1218 may indicate the orientation of the device 1218 and/or a direction of gravitational acceleration or other spatial data.
 In use, the communication device 1210 is physically configured such that the antennas 1214a, 1214b are in a specified spatial arrangement with respect to the orientation device 1218. The physical relationship between the measurement device 1218 and the position of the antennas 1214a, 1214b is thus "known" by the processing system, in the sense that the position of each of the antennas can be inferred by knowledge of the location or other special data relating to the orientation device 1218. By extension, the position of the antennas 1214a, 1214b with respect to another frame of reference can be determined by determining the position of the sensor device 1218 with respect to that frame of reference.
 For example, a frame of reference can be defined by a vector, u, 1233. For illustrative purposes, the vector is taken to be pointing vertically upwards, although it is appreciated that the vector may equally be taken to be pointing downwards, or in any other direction depending on the nature of the output of the measurement device 1218.
 In an exemplary embodiment, the front and rear antennas 1214a, 1214b are positioned at locations 1215a, 1215b which define an axis 1237. The orientation measurement device 1218 measures orientation data, at a point 1239 in the orientation measurement device 1218. The orientation data can be used to determine an antenna vector v, 1235, that is parallel to axis 1237 and is directed from the location 1215a of the front antenna 1214a to the location 1215b of the rear antenna 1214b. The orientation device need not directly measure the vector v, 1235, because the vector v, 1235, could be calculated by processing system 1212, or may be merely inferred, from other parametric data measured by the orientation measurement device 1218.
 By measuring (or inferring) vector, v, with respect to frame of reference vector, u, the processor can determine the orientation of the antenna arrangement (1214a, 1214b) with respect to the frame of reference, u.
 In some circumstances it is advantageous for the processing system 1212 to process data to or from only a subset of the antennas. For example, it may desirable to process data to and/or from only one antenna, being the antenna that is a particular position with respect to reference frame, u. For instance, the foremost antenna in one direction may transmit and/or receive data better than the other antennas in the communications device. In some applications involving the two antennas 1214a, 1214b, the antenna which is displaced highest in (a vertical sense) will transmit better than the other, "lowest", antenna. By measuring (or inferring) vector, v, with respect to frame of reference vector, u, the processor can determine which of the front and rear antennas 1214a and 1214b is displaced the highest, and thereby determine which is the up antenna and which is the down antenna.
 FIG. 13 illustrates an exemplary block diagram showing further details of a device 1210. As shown, central controller 1220 has two orientation measurement devices: accelerometer 1244 and either a gyroscope or magnetometer 1246. However, depending on the accuracy and number of axes measurements required, it can be sufficient to have only a single orientation measurement device, such as where a determination of which antenna is "up" (vertically highest) or "down" (vertically lowest), a single accelerometer will suffice. Accelerometer 1244, having a non-zero measurement under gravity, will provide a different measurement when aligned with or against a gravitational vector force towards the earth. Alternatively, a 3-axis magnetometer, as may be provided by a compass integrated circuit (not shown), can be used to provide a directional vector aligned with or away from the earth. Thus, any change in alignment of antenna vector v, 1235, with respect to vertical vector u, 1233, is measured by the accelerometer or 3-axis magnetometer.
 The processing system 1212 is configured to select one antenna of the two antennas 1214a, 1214b to communicate with (and process data to/from). The selection is controlled by a micro controller unit 1242 based on a determination of a spatial characteristic from the orientation measurement device 1218. The micro controller unit 1242 selects, via antenna switch 1248, one of two electronic signals received at respective inputs 1249 of the processing system, the inputs being connected to respective antennas 1214a and 1214b (in this embodiment, low-profile "patch" antennas). Accordingly, each of the electronic signals at the inputs 1249 corresponds to an electromagnetic signal received by the respective antennas. For a high frequency radio communication, the electromagnetic signals are composed of an information signal modulated onto a high frequency carrier wave.
 The switch 1248 is a semiconductor based circuit, such as a multiplexer, to allow for fast switching between any one of two or more inputs. The switch output is connected to RF transceiver 1251, which extracts the information signal from the selected electronic signal corresponding to the received electromagnetic signal. The information signal is sent to the micro controller unit 1242 for further processing and conversion to an output. The output is fed to audio transducer 1234 via output 1236 of the processing system 1212.
 In an alternative embodiment, rather than having an RF transceiver located between the antenna switch and micro controller unit, the output of the antenna switch may be fed directly to the micro controller unit 1242, with the processing system 1212 including a plurality of RF transceivers between the antenna switch 1248 and respective antennas 1214a, 1214b. In this manner, the antenna switch 1248 selects which of the information signals (that have already been extracted from the electronic signals received from each antenna) are passed to the micro controller unit 1242.
 Operation of the processing system 1212 will now be described with reference to the exemplary embodiment in which the selection of antennas is based on a determination of a spatial characteristic of which antenna is "up". When the output of the accelerometer passes a first predefined spatial threshold, a first orientation is determined, and when the value passes a second pre-determined threshold a second orientation, inverted in comparison with the first orientation is determined. The use of thresholds provides an aid in filtering noise in any electronic signals or erratic movement by the user. The use of different and separated thresholds also enables the processing system 1212 to respond only when a given antenna is sufficiently "up" or "down", which may not be the case when the antenna vector v, 1235, is close to horizontal. For example, an "up" classification may be attributed to the rear antenna 1214b, when the antenna vector, v, 1235 is within 30 degrees of the upward pointing vector, u, 1233. Conversely, the up classification may be attributed to the front antenna 1214a when the antenna vector, v, 1235 is within 180±30 degrees of the upward pointing vector, u, 1233.
 The sensor (e.g. Gyro 1246 accelerometer 1244) output can be smoothed or filtered to prevent rapid switching due to small scale movements that are not indicative changes of orientation of the device 1210.
 To fix the specific physical configuration of, the antennas with respect the orientation measurement device, the communication device 1210 can be incorporated into a physical carrier. In one embodiment, the communication device 1210, such as that of FIG. 12, is incorporated into a wearable item 1222, as shown in FIG. 14. The wearable item 1222 includes a body of material 1224. Antennas 1214a, 1214b are mounted respectively on front and rear ends, 1226a and 1226b, of the body of material 1224. In use, the wearable item 1222 is positioned on top of a person's head 1228 such that the front antenna 1214a and the rear antenna 1214b are located on the front and rear sides of the person's head 1228 respectively. It is appreciated, however, that the item 1222 may be worn on other parts of a person's body, or the communication device 1210 may be incorporated into a garment, or otherwise fastened to other parts of the body.
 The wearable item 1222 is retained on the head of the wearer by a swimming cap 1232. The item 1222 also includes two audio transducers in the form of audio bone conduction transducers 1230, which are held down and in proximity to the wearer's skull, by the swimming cap 1232. The audio transducers 1230 permits a first person, such as a coach, to verbally communicate with the swimmer, wearing item 1222. The audio bone conduction transducers 1230 may also be used to allow a person to hear automated timing measurements or pacing prompts generated by processing system 1212. The transmission of audio signals from the processing system 1212 to the swimmer may, additionally or alternatively, be provided by a water resistant in-ear earphone 1234.
 In a particularly advantageous embodiment, illustrated in FIG. 14A, communication device 1210A is adapted configured such that wearable item 1222a is a headband. The headband is comprised of an elastically deformable material, such as a resilient rubber, eg latex, a wet-suit material, or some other stretchy material, so that it can hold itself in the shape of a ring around a persons head, without the need for an overlain swimming cap. Each of the components of device 1210 may be incorporated into the headband 1222a, with the antennas 1214(a,b), bone conduction transducers 1230, and controller 1220 suitably positioned to maintain their functions as described herein. An earphone 1234 is also optionally included, and hangs down from the wearable item 1220A. In the embodiment of FIG. 14, the antennas 1214a and 1214b of FIG. 14A are included on opposite sides of the headband so that the front antenna 1214a and rear antenna 1214b can be positioned at the front and rear sides of a person's head. Bone conduction transducers 1230 are positioned on the headband approximately midway between the antennas 1214(a,b). More precisely, the bone conduction transducers 1230 are positioned in the headband so as to sit above and just behind a corresponding ear of the person. The central controller 1220 is located above and just in front of one of the ears. A battery 1221 for powering the circuitry 1220, 1214(a,b), 1230, 1234, is located above and just in front of the other ear.
 While the communication devices 1210, 1210A are particularly advantageous in aquatic environments, it is appreciated that the device will also function outside of aquatic environments. The communication device 1210A, for example, being wearable without a swim cap, is well suited to other sporting activities, eg tennis, athletics and football, in which changes to the person's orientation may lead to improved radio wave detection at one antenna compared to a different antenna. However, so as to be suited for aquatic environments, the communication devices 1210, 1210A are preferably waterproof using materials and a construction known in the art to be suitable for such devices. An example of a water-proof headband audio device that utilises bone conduction antennas is described in U.S. Pat. No. 7,310,427.
 The invention will now be described by way of an example application, specifically that of communicating with a swimmer wearing the device 1210. In the embodiment described below, the device 1210 is worn on the swimmer by wearing item 1222 within swimming cap 1232. When the swimmer is face down in a body of water, as shown in FIG. 15A, for example when swimming freestyle, the front antenna 1214a' is beneath the surface 1240 of the water and the rear antenna 1214b' is above the surface 1240 of the water. The front antenna 1214a', being underwater, will be less effective than the rear antenna 1214b' in receiving and/or transmitting high-frequency electromagnetic radio waves, typically in the 2.4-2.5 GHz Industrial, Scientific and Medical (ISM) band, as these frequencies are very close to the microwave absorption frequency of water, with signals only propagating a few centimetres through the water. Having determined that the front antenna is the down antenna, and the rear antenna is the up antenna, the processing system determines that the rear "up" antenna 1214b' should be used for communications.
 The micro controller unit 1242, accordingly selects the up antenna via antenna switch 1248, which results in only the up antenna being connected to the RF transceiver 1251. Thus, an electromagnetic signal received by the up antenna is processed to extract the information signal from the carrier wave of the received signal. The down antenna, on the other hand, is disconnected from the RF transceiver 1251, thereby saving the system 1212 from having to process data from the down antenna. In this manner, power consumption by the communication device 1210 is reduced compared to having to analyse and/or process data from both antennas. Additionally, the power consumption of a device that transmits a signal to the communication device 1210 may be low power, as a low power signal will be detectable by antenna 1214b'.
 When the swimmer is face up in the water, as shown in FIG. 15B, for example when swimming backstroke, the orientation of the device 1210 is reversed such that the front antenna 1214a'' is above water (up) and the rear antenna 1214b' is below water (down). The processing system 1212 accordingly switches the source of processed data from the rear antenna to the front antenna.
 It is appreciated that the communication system may include more than two antennas whereby a subset of one or more of the antennas may be selected. For example, additional antennas (not shown) may be placed on opposing lateral sides of the swimmer's head. To provide an "up" antenna when the person's head is on its side. Such an arrangement would allow, for example, having the rear and/or right-side antenna operational, while the front and left-side antenna are deactivated, should such a configuration be desired.
 It is also appreciated that other ways may readily be utilised to determine the relative positioning of the antennas. For example, an orientation device may be placed in a fixed physical relationship to each antenna, so that the absolute orientation of each antenna is known. The processing device 1212 can then determine from the absolute orientations, which antenna(s) to select.
 In the above exemplary embodiments, the communication device acts as a receiver only (the transceiver 1251 in this case need only be a receiver). However, it is appreciated that the communication device 1210 may also transmit information wirelessly via any subset one or more of the antennas. Accordingly, efficient transmission from the communication device 1210 may be achieved by transmitting only on the preferred antenna(s), eg the up antenna. A microphone (not shown) may be attached to the processing system 1212 to allow the swimmer to communicate to the coach. However, the information transmitted from the communication device need not be audio data. In an advantageous embodiment, the transmitted data is (or includes) physiological parameters measured on the swimmer (e.g. heart rate etc). The data transmitted by the communications device 1210 is received by a second communications device, such as timing device 102 via timing communications sub system 308. Thus, communcations device 1210 and timing device 102 form a two-way communications system. It will be understood that the invention disclosed and defined in this specification extends to all alternative combinations of two or more of the individual features mentioned or evident from the text or drawings. All of these different combinations constitute various alternative aspects of the invention.
Patent applications in class Mechanical stop time type
Patent applications in all subclasses Mechanical stop time type