Patent application number | Description | Published |
20090177095 | TRIAXIAL FIBER OPTIC FORCE SENSING CATHETER - A fiber optic force sensing assembly for detecting forces imparted at a distal end of a catheter assembly. The structural member may include segments adjacent each other in a serial arrangement, with gaps located between adjacent segments that are bridged by flexures. Fiber optics are coupled to the structural member. In one embodiment, each fiber optic has a distal end disposed adjacent one of the gaps and oriented for emission of light onto and for collection of light reflected from a segment adjacent the gap. The optical fibers cooperate with the deformable structure to provide a change in the intensity of the reflected light, or alternatively to provide a variable gap interferometer for sensing deformation of the structural member. In another embodiment, the gaps are bridged by fiber Bragg gratings that reflect light back through the fiber optic at central wavelengths that vary with the strain imposed on the grating. | 07-09-2009 |
20090287092 | Temperature compensated strain sensing catheter - A strain sensing assembly implements thermal management and/or temperature measurement techniques to adequately mitigate against and compensate for temperature changes in optical fiber strain sensors of a distal end of a catheter. In one embodiment, the distal end of the catheter includes an end effector such as an ablation head that introduces significant thermal temperature changes proximate the distal end of the catheter. In one embodiment, a plurality of temperature sensors is utilized for accurate determination of each of a plurality of optical fiber strain sensors. In other embodiments, a single temperature sensor may be utilized by implementing thermal management techniques that adequately reduce temperature differences between the single temperature sensor and the plurality of optical fiber strain sensors. | 11-19-2009 |
20120078138 | MEDICAL APPARATUS SYSTEM HAVING OPTICAL FIBER LOAD SENSING CAPABILITY - Apparatus is provided for diagnosing or treating an organ or vessel, wherein a device having at least two optical fiber sensors disposed in a distal extremity thereof is coupled to processing logic programmed to compute a multi-dimensional force vector responsive to detected changes in the optical characteristics of the optical fiber sensors arising from deflection of the distal extremity resulting from contact with the tissue of the wall of the organ or vessel. The force vector may be used to facilitate manipulation of the catheter either directly or automatically using a robotic system. | 03-29-2012 |
20140121537 | TRIAXIAL FIBER OPTIC FORCE SENSING CATHETER - A fiber optic force sensing assembly for detecting forces imparted at a distal end of a catheter assembly. The structural member may include segments adjacent each other in a serial arrangement, with gaps located between adjacent segments that are bridged by flexures. Fiber optics are coupled to the structural member. In one embodiment, each fiber optic has a distal end disposed adjacent one of the gaps and oriented for emission of light onto and for collection of light reflected from a segment adjacent the gap. The optical fibers cooperate with the deformable structure to provide a change in the intensity of the reflected light, or alternatively to provide a variable gap interferometer for sensing deformation of the structural member. In another embodiment, the gaps are bridged by fiber Bragg gratings that reflect light back through the fiber optic at central wavelengths that vary with the strain imposed on the grating. | 05-01-2014 |
Patent application number | Description | Published |
20080294144 | Touch Sensing Catheter - A touch sensing catheter having a strain sensor assembly that may resolve the magnitude and direction of a force exerted on a distal extremity of the catheter, the strain sensor assembly being substantially insensitive to bulk temperature changes. A deformable structure having a plurality of optical fibers associated therewith that are strained by the imposition of a contact force transferred thereto. The optical fibers cooperate with the deformable structure to effect variable gap interferometers, such as Fabry-Perot resonators, that vary in operative length when a force is exerted on the deformable structure. The strain sensor assembly is rendered insensitive to bulk temperature changes by matching the coefficient of thermal expansion of the deformable body with that of the optical fibers. The strain sensor assembly may also be configured to mitigate the effects of thermal gradients using various thermal isolation techniques. | 11-27-2008 |
20100298826 | METHOD AND APPARATUS FOR CONTROLLING LESION SIZE IN CATHETER-BASED ABLATION TREATMENT - A method and apparatus that utilizes a force-time integral for real time estimation of lesion size in catheter-based ablation systems. The apparatus measures the force exerted by a contact ablation probe on a target tissue and integrates the force over an energization time of the ablation probe. The force-time integral can be calculated and utilized to provide an estimated lesion size (depth, volume and/or area) in real time. The force-time integral may also account for variations in the power delivered to the target tissue in real time to provide an improved estimation of the lesion size. In one embodiment, the force metric can be used as feedback to establish a desired power level delivered to the probe to prevent steam popping. | 11-25-2010 |
20110263934 | CATHETER HAVING TRI-AXIAL FORCE SENSOR - A catheter for diagnosis or treatment of a vessel or organ is provided in which a flexible elongated body includes a tri-axial force sensor formed of a housing and a plurality of optical fibers associated with the housing that measure changes in the intensity of light reflected from the lateral surfaces of the housing resulting from deformation caused by forces applied to a distal extremity of the housing. A controller receives an output of the optical fibers and computes a multi-dimensional force vector corresponding to the contact force. | 10-27-2011 |
20120179068 | Medical Apparatus System Having Optical Fiber Load Sensing Capability - An apparatus and method for diagnosis or treatment of a vessel or organ. The apparatus includes a deformable body such as a catheter having a tissue ablation end effector and an irrigation channel in fluid communication therewith. At least two sensors are disposed within a distal extremity of the deformable body, the sensors being responsive to a wave in a specified range of frequency to detect deformations resulting from a contact force applied to the distal extremity. A microprocessor can be operatively coupled with the sensors to receive outputs therefrom, the microprocessor being configured to resolve a multi-dimensional force vector corresponding to the contact force. In one embodiment, the sensors are fiber Bragg grating sensors, and the wave is injected into the fiber Bragg grating strain sensors from a laser diode. | 07-12-2012 |
20120265102 | COMPACT FORCE SENSOR FOR CATHETERS - An ablation catheter system configured with a compact force sensor at a distal end for detection of contact forces exerted on an end effector. The force sensor includes fiber optics operatively coupled with reflecting members on a structural member. In one embodiment, the optical fibers and reflecting members cooperate with the deformable structure to provide a variable gap interferometer for sensing deformation of the structural member due to contact force. In another embodiment, a change in the intensity of the reflected light is detected to measure the deformation. The measured deformations are then used to compute a contact force vector. In some embodiments, the force sensor is configured to passively compensate for temperature changes that otherwise lead to erroneous force indications. In other embodiments, the system actively compensates for errant force indications caused by temperature changes by measuring certain local temperatures of the structural member. | 10-18-2012 |