Described embodiments include a catheter, which includes a plurality of splines at a distal end of the catheter, and a plurality of helical conducting elements disposed on the splines. Other embodiments are also described.

Described embodiments include an apparatus that includes an expandable structure, configured for insertion into a body of a subject, and a plurality of conducting elements coupled to the expandable structure. Each of the conducting elements comprises a respective coil and has an insulated portion that is electrically insulated from tissue of the subject, and an uninsulated portion configured to exchange signals with the tissue, while in contact with the tissue. Other embodiments are also described.

An apparatus for monitoring for accumulation of lung fluid comprises a feeding tube having first electrode(s) positioned thereon for electrical contact with tissue of an esophagus of a target patient including a lower esophageal sphincter (LES) and/or tissue in proximity to the LES, second electrode(s) sized and shaped for contacting skin of the target patient, and a non-transitory memory having stored thereon code instructions for applying alternating current(s) to pair(s) of first and second electrodes, measuring a voltage over the pair(s), and computing an estimate of a change of lung fluid relative to a baseline in lung(s) of the target patient according to the applied alternating current and measured voltage, wherein the applying, the measuring, and the computing the estimate of the change in lung fluid are iteratively executed for monitoring the target patient for accumulation of lung fluid while the feeding tube is in use.

A system for assessing occlusion of a region to blood flow includes a catheter with an inflatable member, a first electrode configured for placement upstream of the inflatable member and the second electrodes configured for placement downstream of the inflatable member, the inflatable member configured for inflation to occlude the blood flow through the region. The system further includes a current/voltage source, a resistor and a voltmeter, wherein these components along with the first and second electrodes are configured to form an impedance measuring circuit configured to detect a change in impedance for indicating occlusion of the region to the blood flow.

One aspect of the present disclosure relates to a system for monitoring a diaphragmatic twitch response. The diaphragmatic twitch response can be used to determine a depth of neuromuscular blockade. The system includes a neural stimulation device to stimulate a phrenic nerve of a subject, which has the effect of stimulating the subject's diaphragm. The system also includes a monitor to detect the diaphragm's response to the stimulation. For example, the monitor can include a nasogastric tube with two distally positioned inflatable balloons. Each of the inflatable balloons is coupled to a sensor to measure a corresponding pressure (e.g., an esophageal pressure and a gastric pressure). The pressure differential between the esophagus above the diaphragm and the stomach below the diaphragm (also referred to as the transdiaphragmatic pressure) can be used as a measure of the diaphragmatic twitch response.

A device for in vivo detecting and quantifying a concentration of an analyte in a peritoneal fluid of a subject. The device includes (a) a catheter having an open proximal end configured to be disposed external to the subject, an open distal end configured to be disposed within the peritoneal cavity comprising the peritoneal fluid, an anchor portion, an outer wall, and an inner wall, (b) a sensor disposed adjacent to the open distal end and configured to detect and quantify the concentration of the analyte in the peritoneal fluid, and (c) a main control unit disposed external to the subject, connected to the sensor via a wire, and configured to control the sensor, receive and store detection and quantification data from the sensor, and transmit the data to a second device. A portion of the wire is disposed between the inner wall and the outer wall of the catheter.

A ureteral catheter includes a drainage lumen having a proximal portion configured to be positioned in at least a portion of a patient's urethra and/or bladder and a distal portion configured to be positioned in a patient's kidney, renal pelvis, and/or in the ureter adjacent to the renal pelvis. The distal portion includes a retention portion for maintaining positioning of the distal portion of the drainage lumen. The retention portion includes a plurality of sections, each section having one or more openings on a sidewall of the retention portion for permitting fluid flow into the drainage lumen. A total area of openings of a first section of the plurality of sections is less than a total area of openings of an adjacent second section of the plurality of sections. The second section is closer to a distal end of the drainage lumen than the first section.

A method for introducing an elongate medical instrument with a shaped portion into the body of a subject includes at least partially straightening the shaped portion from an exterior of the elongate medical instrument. A retention element may then be introduced into an interior of the shaped portion to maintain the shaped portion in an at least partially straightened configuration as the external force is removed from the shaped portion. With the retention element in place, the shaped portion may be introduced to a desired location within a hollow interior of an internal organ. The retention element may then be removed to enable the shaped portion to return to its desired shape. A straightening apparatus includes the retention element, as well as an external element that at least partially straightens the shaped portion of the elongate medical instrument from the outside. A system includes the elongate medical instrument and the straightening apparatus.

A catheter insertable into a patient for monitoring pressure having an expandable outer balloon. An expandable inner balloon is positioned within the lumen of the catheter and has having a second outer wall and forms a gas chamber to monitor pressure within the patient. In response to pressure exerted on the outer wall of the outer balloon, fluid within the outer balloon enters an opening in the wall of the catheter lumen to exert a pressure on the outer wall of the expanded inner balloon to deform the inner balloon and compress the gas within the inner balloon. A pressure sensor communicates with the gas containing chamber for measuring pressure based on compression of gas caused by deformation of the expanded inner balloon resulting from deformation of the expanded outer balloon.

A system includes an expandable distal-end assembly, a proximal position sensor, a distal position sensor, and a processor. The expandable distal-end assembly is coupled to a distal end of a shaft for insertion into a cavity of an organ of a patient. The proximal and distal position sensors are located at a proximal end and a distal end of the distal-end assembly, respectively. The processor is configured to estimate a position and a longitudinal direction of the proximal sensor, and a position of the distal sensor, all in a coordinate system used by the processor. The processor is further configured to project the estimated position of the distal sensor on an axis defined by the estimated longitudinal direction, and calculate an elongation of the distal-end assembly by calculating a distance between the estimated position of the proximal sensor and the projected position of the distal sensor.