Devices, systems, and techniques are disclosed for determining spatial relationships between electrodes implanted within a patient. In one example, a medical device delivers, via a first electrode, an electrical stimulus and senses, for each other electrode, a respective electrical signal indicative of the electrical stimulus. The medical device determines, for each other electrode, a respective value for each respective electrical signal. The medical device determines, based on the respective values for each respective electrical signal and values of tissue conductivity of tissues of the patient interposed between the first electrode and the other electrodes, spatial relationships between the first electrode and each other electrode of the plurality of electrodes.

A ring for photoplethysmographic sensing performs transmissive PPG and/or reflective PPG. It can enable lower power consumption, higher fidelity, and/or greater versatility to different use cases and users' specificities. The PPG system takes advantage of sensor spatial diversity to enhance the quality and the reliability of the PPG measurements in smart rings, for example. It can also perform user identification.

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, including either suspending or adjusting turn schedule based on various types of patient movement. Compliance with Head-of-Bed protocols can also be performed based on actual patient position instead of being inferred from bed elevation angle. The sensor can include bi-axial or tri-axial accelerometers, as well as resistive, inductive, capacitive, magnetic and other sensing devices, depending on whether the sensor is located on the patient or the support surface, and for what purpose.

Systems and methods are described for implementing a catheter model to estimate shape of a deformable catheter in a three-dimensional space. The catheter model includes two or more model segments that correspond to two or more segments of the deformable catheter. Each model segment includes a length and location of model electrode(s) and/or model magnetic sensor(s) corresponding electrodes and/or magnetic sensors of the deformable catheter. Variable shape parameter define a curvature of the segment. Varying the shape parameters generates a plurality of potential catheter shapes. In conjunction with generating the potential catheter shapes, impedance and/or magnetic responses (e.g., measured responses) are obtained for the physical electrodes and/or physical magnetic sensors of the deformable catheter. Using a selected one (e.g., most likely) of the potential catheter shapes and the measured responses, the shape parameters are updated and a catheter shape is generated and displayed.

A sensor, such as a photoplethysmography sensor, for non-invasively monitoring a characteristic of an organism, such as a vital body sign. The sensor has multiple light sources disposed on a substrate and an array of optical probing channels for conveying light from the light sources to a probed region. Each detector pixel of an array of detector pixels receives light from a respective optical detection channel after interaction with a subregion of the probed region and spatial filtering, and generates a corresponding pixel signal. A processor derives a value of the vital body sign based at least upon the plurality of pixel signals

A device includes source and detector sensors. In a specific implementation, the device has two near detectors, two far detectors, and two sources. The two near detectors are arranged closer to the two sources than the two far detectors. A light-diffusing layer covers the two near detectors. The device may be part of a medical device that is used to monitor or measure oxygen saturation levels in a tissue. In a specific implementation, light is transmitted into the tissue and received by the detectors. An attenuation coefficient is first calculated for a shallow layer of tissue. The attenuation coefficient is then used to calculate an attenuation coefficient for a deep layer of tissue.

A method for identifying and treating tissue includes providing an electrosurgical treatment device including an electrode assembly. One or more electrical property values of target tissue are measured. The measured electrical property values of the target tissue are compared against electrical property values of known tissue types. A tissue type of the target tissue is identified. An energy delivery configuration of the electrosurgical treatment device is adjusted to the type of target tissue. The electrosurgical treatment device is activated to treat the target tissue.

Disclosed is a system and method for in-situ and instantaneous measurement of a pressure gradient by real-time localized pressure measurement with two or more pressure sensors, operating with respect to blood pressure gradient across the aortic valve, or other heart valves, and associated regurgitation of blood flow due to leakage resulting from insufficient valve closure. The system includes a multi-sensor catheter, with sensors arranged along the length of the distal segment of the catheter body, spaced apart to provide simultaneous pressure measurement on either side of the valves of the heart, in addition to one or more lumina in the core of the catheter that will provide a path for introduction of diagnostic fluids which flow out through a multitude of holes in the body of the distal segment of the catheter body.

A system for in-vivo monitoring of intracranial pressure is provided. The system includes a probe and a controller. The probe includes optical emitters and optical detectors. The optical detectors detect light emitted by the optical emitters generate signals representative of the detected light. The controller includes memory and processor. The controller connects to the probe to energize the optical emitters and receiving signals from the optical detectors. The system may include modelling, extraction, and pressure prediction modules. The modelling module can relate intracranial pressure to features of an optical signal representative of a degree to which light input into a subject's skull is absorbed by the subject's brain. The extraction module can extract signal features from a signal derived from the optical signals output by the detectors. The pressure prediction module can input the signal features into the modelling module and output an indication of intracranial pressure.

An imaging system may include: a first light source configured to emit a first source spectrum of collimated light; a second light source configured to emit a second source spectrum of light; a probe head configured to direct the first source spectrum and the second source spectrum toward tissue in an oral cavity and to collect a first feedback spectrum of light and a second feedback spectrum of light; an interferometry sub-system to generate an optical feedback signal using the first source spectrum; at least one optical sensor array for receiving the optical feedback signal and the second feedback spectrum; and at least one programmable processor to generate: a first diagnostic image of the tissue using the optical feedback signal; a second diagnostic image of the tissue using the second feedback spectrum; and a third diagnostic image from a combination of the first diagnostic image and the second diagnostic image.