781results about "Strain gauge" patented technology

A wearable platform embodied in a belt or flattened patch-like central body shaped to conform to the abdomen provides physiological monitoring of soldiers during field operations or trauma victims at accident sites and makes health state assessments. The platform includes sensors for heart rate, body motion, respiration rate and intensity, and temperature and further contains a microprocessor and short range transmitter. The respiration sensor uses conductive ink in a novel manner. A small square of the ink is coated on an arched structure so that flexing of the arch either to increase or decrease its radius of curvature modifies the resistance of the structure. This is utilized to set the unstressed resistance of the arch structure and to allow a greater range of resistance values capable of measuring distortions in different deformations of the arch. The respiration sensor supplements the motion information provided by an accelerometer sensor.

Apparatus is provided for diagnosing or treating an organ or vessel, wherein a deformable body 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 deformable body either directly or automatically using a robotic system.

A system for monitoring medical conditions including pressure ulcers, pressure-induced ischemia and related medical conditions comprises at least one sensor adapted to detect one or more patient characteristic including at least position, orientation, temperature, acceleration, moisture, resistance, stress, heart rate, respiration rate, and blood oxygenation, a host for processing the data received from the sensors together with historical patient data to develop an assessment of patient condition and suggested course of treatment. In some embodiments, the system can further include a support surface having one or more sensors incorporated therein either in addition to sensors affixed to the patient or as an alternative thereof. The support surface is, in some embodiments, capable of responding to commands from the host for assisting in implementing a course of action for patient treatment. The sensor can include bi-axial or tri-axial accelerometers, as well as resistive, inductive, capactive, magnetic and other sensing devices, depending on whether the sensor is located on the patient or the support surface, and for what purpose.

Aspects of the present disclosure are presented for a surgical instrument having one or more sensors at or a near an end effector and configured to aide in the detection of tissues and other materials and structures at a surgical site. The detections may then be used to aide in the placement of the end effector and to confirm which objects to operate on, or alternatively, to avoid. Examples of sensors include laser sensors used to employ Doppler shift principles to detect movement of objects at the surgical site, such as blood cells; resistance sensors to detect the presence of metal; monochromatic light sources that allow for different levels of absorption from different types of substances present at the surgical site, and near infrared spectrometers with small form factors.

The presence or absence of objects tagged with transponders may be determined in an environment in which medical procedures are performed via an interrogation and detection system which includes a controller and a plurality of antennas positioned along a patient support structure. The antennas may be positioned along an operating table, bed, mattress or pad, sheet, or may be positioned on a drape, or shade. Respective antennas may successively be activated to transmit interrogation signals. Multiple antennas may be monitored for responses from transponders to the interrogation signals. For example, all antennas other than the antenna that transmitted the most recent interrogation signal may be monitored. Antennas may be responsive to force, a signal indicative of such force being produced. A wireless physiological condition monitor may detect patient physiological conditions and wirelessly transmit signals indicative of such.

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.

A tension mechanism for a robotically-controlled medical device measures the tension applied to an actuation tendon to provide feedback to a robotic controller. In one embodiment, the device comprises an elongated instrument, an elongated member, and a base. The elongated member is coupled to the distal end of the elongated instrument, configured to actuate the distal end of the elongated instrument in response to tension in the elongated member. The base is located at the proximal end of the elongated instrument, and comprises a first redirect surface that redirects the elongated member. The first redirect surface is coupled to a lever element that is configured to exert a reactive force on a sensor in response to tension in the elongated member.

Systems and methods are disclosed that use wireless coupling of energy for operation of both external and internal devices, including external sensor arrays and implantable devices. The signals conveyed may be electronic, optical, acoustic, biomechanical, and others to provide in situ sensing and monitoring of internal anatomies and implants using a wireless, biocompatible electromagnetic powered sensor systems.

This application relates to an apparatus and system for sensing strain on a portion of an implant positioned in a living being. In one aspect, the apparatus has at least one sensor assembly that can be mountable thereon a portion of the implant and that has a passive electrical resonant circuit that can be configured to be selectively electromagnetically coupled to an ex-vivo source of RF energy. Each sensor assembly, in response to the electromagnetic coupling, can be configured to generate an output signal characterized by a frequency that is dependent upon urged movement of a portion of the passive electrical resonant circuit and is indicative of strain applied thereon a portion of the respective sensor assembly.

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.

A sensing system is provided for measuring various joints of a human body for applications for performance animation, biomechanical studies and general motion capture. One sensing device of the system is a linkage-based sensing structure comprising rigid links interconnected by revolute joints, where each joint angle is measured by a resistive bend sensor or other convenient goniometer. Such a linkage-based sensing structure is typically used for measuring joints of the body, such as the shoulders, hips, neck, back and forearm, which have more than a single rotary degree of freedom of movement. In one embodiment of the linkage-based sensing structure, a single long resistive bend sensor measures the angle of more that one revolute joint. The terminal ends of the linkage-based sensing structure are secured to the body such that movement of the joint is measured by the device. A second sensing device of the sensing system comprises a flat, flexible resistive bend sensor guided by a channel on an elastic garment. Such a flat sensing device is typically used to measure various other joints of the body which have primarily one degree of freedom of movement, such as the elbows, knees and ankles. Combining the two sensing devices as described, the sensing system has low sensor bulk at body extremities, yet accurately measures the multi-degree-of-freedom joints nearer the torso. Such a system can operate totally untethered, in real time, and without concern for electromagnetic interference or sensor occlusion.

A force-sensing catheter for diagnosing or treating the vessels found within a body or body space includes a center strut that is bonded, preferably thermally, along its longitudinal axis with the thermoplastic tubular member within which it is housed. The tubular member preferably has three layers: an inner layer, a braided layer and an outer layer. One or more semiconductor or metallic foil strain gages are affixed to the center strut in order to provide a measure of the bending and torsional forces on the distal tip of the catheter. Temperature compensation is achieved by having a temperature sensor near the strain gages and calibrating the catheter over a range of temperatures.

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.

An article of footwear includes an upper member and a sole structure, with a sensor system connected to the sole structure. The sensor system includes a plurality of sensors that are configured for detecting forces exerted by a user's foot on the sensor. Each sensor includes two electrodes that are in communication with a force sensitive resistive material. The electrodes and the force sensitive resistive material may have multi-lobed shapes. Additionally, the sensor system may be provided on an insert that may form a sole member of the article of footwear. The insert may have slits therethrough, and may have a defined peripheral shape.

Described herein are devices, systems and methods for determining if a nerve is nearby a device or portion of a device. The neural stimulation tools described herein are configured to be flexible and low-profile, so that they can be used within body regions that may be tortuous or difficult to reach, such as within a compressed or partially occluded neural foramen. In most cases, these tools described herein are ribbon-shaped and adapted to be manipulated bimanually, for example, by applying force to the ends of the devices from separate locations outside of the patient's body. Thus, in some of the exemplary neural localization devices described herein, the distal end region of the device are configured to couple to the proximal end of a guidewire. One or more surfaces of the devices may include an electrode or multi-polar network of electrodes configured to stimulate only nerves within a predetermined distance of a particular face of the device.

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.

There is provided herein a sensor for use in patient monitoring, wherein the level of patient activity in a chair or bed is tracked to determine whether or not that patient has exhibited sufficient activity to merit eliminating a scheduled assisted relocation to a new position. The instant device senses the time since a patient last relocated into a different sitting or lying position. If the patient has not moved during some predetermined time period, the nursing staff will be notified that it is time to manually reposition the patient. On the other hand, if the patient has significantly changed position, the device will not signal to the caregiver that a move is necessary, thereby eliminating the need in some cases to rouse the patient from an otherwise sound sleep.

An implantable vessel filter having an integrated sensing capability for monitoring the condition of the vessel filter. In one variation, the vessel filter comprises a plurality of legs that would themselves perform as a sensor device for detecting distention, which would indicate the presence of a clot or thrombus therein. A passive electrical circuit may be implemented on the vessel filter to receive electromagnetic energy and transmit signals indicative of the condition of the implanted vessel filter. In another variation, a miniaturized sensor is adapted for measuring the strain and / or other physical parameters of the filter legs.

A wearable device having feedback characteristics including a compliant article that is arranged to extend over an anatomical portion of a wearer. Sensors provided with the wearable device detect the orientation of a joint and send signals to a processor for analysis. When the processor determines that the joint is in an unsafe or potentially injurious configuration, a feedback or response mechanism is activated to alert the user to such a condition and / or to provide substantially rigid structural support to the joint. The device may also be used to condition users to maintain the joint in proper orientations to avoid injuries, or to condition an amputee to use more effective motions to achieve a more natural gait.

An elastic strain sensor can be incorporated into an artificial skin that can sense flexing by the underlying support structure of the skin to detect and track motion of the support structure. The unidirectional elastic strain sensor can be formed by filling two or more channels in an elastic substrate material with a conductive liquid. At the ends of the channels, a loop port connects the channels to form a serpentine channel. The channels extend along the direction of strain and the loop portions have sufficiently large cross-sectional area in the direction transverse to the direction of strain that the sensor is unidirectional. The resistance is measured at the ends of the serpentine channel and can be used to determine the strain on the sensor. Additional channels can be added to increase the sensitivity of the sensor. The sensors can be stacked on top of each other to increase the sensitivity of the sensor. In other embodiments, two sensors oriented in different directions can be stacked on top of each other and bonded together to form a bidirectional sensor. A third sensor formed by in the shape of a spiral or concentric rings can be stacked on top and used to sense contact or pressure, forming a three dimensional sensor. The three dimensional sensor can be incorporated into an artificial skin to provide advanced sensing.

Methods for evaluating motion of a cardiac tissue location, e.g., heart wall, are provided. In the subject methods, timing of a signal obtain from a strain gauge stably associated with the tissue location of interest is employed to evaluate movement of the cardiac tissue location. Also provided are systems, devices and related compositions for practicing the subject methods. The subject methods and devices find use in a variety of different applications, including cardiac resynchronization therapy.

A surgical instrument includes a force sensor apparatus that is immune to noise from arcing cautery without relying on fiber optic strain gauges, and that is autoclabable. The surgical instrument includes a housing, a shaft, the force sensor apparatus, a joint, and an end component. The force sensor apparatus includes at least one strain gauge that is enclosed in a Faraday cage. The Faraday cage includes a sensor capsule that includes one or more strain gauges, a cable shield tube connected to the sensor capsule, and an electronics enclosure connected to the cable shield tube. The sensor capsule is positioned between the joint and the shaft. The cable shield tube extends through the shaft to the electronics enclosure that is within the housing.