According to some embodiments, systems for facilitating consistent radiometric tissue contact detection independent of orientation comprise a medical instrument having an antenna positioned at a distal end, an energy delivery element positioned at a distal end of the medical instrument, a radiometer, an impedance transformation network positioned between the antenna and the radiometer, and a processor configured to receive an input signal from the radiometer and provide an output indicative of an amount of tissue contact based upon the input signal. The impedance transformation network may be tuned to provide a substantially uniform radiometric response independent of an orientation of the antenna with respect to the tissue as the antenna is brought into contact with the tissue of a subject.

Methods and apparatus for guiding medical care based on sensor data from the gastrointestinal tract are described utilizing an apparatus which can be used with enteral feeding. Generally, the apparatus includes an elongated body having a length configured for insertion into a stomach and at least one pair of electrodes located along the length of the elongated body and positionable for placement within the stomach. A controller in electrical communication with the at least one pair of electrodes is included and the control may also be configured to measure a conductivity or impedance between the pair of electrodes and to determine a gastric residual volume of the stomach based on the measured conductivity or impedance.

An access device for accessing an intervertebral disc having an outer shield comprising an access shield with a larger diameter (˜16-30 mm) that reaches from the skin down to the facet line, with an inner shield having a second smaller diameter (˜5-12 mm) extending past the access shield and reaches down to the disc level. This combines the benefits of the direct visual microsurgical/mini open approaches and the percutaneous, “ultra-MIS” techniques.

A system and method for determining a position of a medical device within a body are provided. The system includes an electronic control unit that receives position signals from position sensors of a first type and a second type disposed on the device and applies a filter to each of the position signals to obtain filtered estimated positions for each sensor. The unit computes a spline connecting the position sensors of the first type responsive to the filtered estimated positions for the sensors and estimates a spline position for the sensor of the second type along the spline. The unit generates maps between the spline position and filtered and unfiltered estimated positions for the sensor of the second type and determines actual positions for the sensors of the first type responsive to the filtered estimated position for the sensors and a composite map of the two maps.

A wearable physiological sensor has a housing and a gas-permeable support structure carried by the housing, which contacts the skin of the subject. An air space is provided between the support structure and the housing. Movement of the support structure relative to the housing is sensed. This provides a sensor which is comfortable for the subject and provides good sensitivity in that motion being detected (e.g. an arterial pulse) only needs to impart kinetic energy to the support structure, with a relatively low inertia.

A method and system for determining a location of a treatment element relative to an anatomical feature and for estimating contact between the treatment element and the anatomical feature in the context of a navigation system. The system may include a medical device including at least one treatment element and at least one navigation electrode and a navigation system in communication with the one or more navigation electrodes, the navigation system including a processing unit. The processing unit may be programmed to determine a plurality of points that define a surface geometry of the at least one treatment element, calculate a distance between each of the points and a closest point on the anatomical feature, and estimate the likelihood of contact between the points.

A temperature probe includes a handle and a shaft extending from the handle. The shaft includes a distal end, a proximal end, and a tip at the distal end. The temperature probe also includes a capacitance sensor disposed on one of the handle and the shaft, the capacitance sensor configured to measure a change in capacitance when positioned proximate a conductor. The temperature probe further includes a temperature sensor disposed on the shaft, the temperature sensor configured to measure a body cavity temperature of a patient.

A method is described for determining biological tissue type based on a complex impedance spectra obtained from a probe with a conducting part adjacent a tissue region of interest, wherein the impedance spectra includes data from a number of frequencies. The method may include: obtaining, from the complex impedance spectra, a first data set representative of impedance modulus values, or equivalent admittance values, at one or more frequencies, obtaining, from the complex impedance spectra, a second data set representative of impedance phase angle values, or equivalent admittance values, at one or more different frequencies, applying a first discrimination criterion to the first data set, applying a second discrimination criterion to the second data set, and thereby determining if the tissue region of interest is a tissue type characterised by the discrimination criteria.

A tracker system for use in image guided surgery is disclosed. The tracker system may couple to wet tissue and may include a navigation tracker and a base pad that couple to each other. The base pad may be fabricated from a plurality of nonwoven nanofibers. The base pad is configured to couple to body tissue of a patient via at least one of adsorption, hydration equilibrium, and macromolecular interpenetration.

A device positionable in a cavity of a bodily organ (e.g., a heart) may discriminate between fluid (e.g., blood) and non-fluid tissue (e.g., wall of heart) to provide information or a mapping indicative of a position and/or orientation of the device in the cavity. Discrimination may be based on flow, or some other characteristic, for example electrical permittivity or force. The device may selectively ablate portions of the non-fluid tissue based on the information or mapping. The device may detect characteristics (e.g., electrical potentials) indicative of whether ablation was successful. The device may include a plurality of transducers, intravascularly guided in an unexpanded configuration and positioned proximate the non-fluid tissue in an expanded configuration. Expansion mechanism may include helical member(s) or inflatable member(s).