Abstract: Methods, apparatus, and systems are provided to control contraction of the heart. At least one sensing element receives signals indicating electrical activity of sinus rhythm of the heart. Based on the received signals, the progress of contraction of the heart is determined. Based on the progress of contraction, the chamber of the heart may then be stimulated at a plurality of locations. In another embodiment, a plurality of electrodes are implanted in the left ventricle to stimulate at multiple locations in the left ventricle for the purpose of improving hemodynamic performance and increasing cardiac output in a patient who is suffering from congestive heart failure.

Abstract: A large area monitoring device for diagnosing easily performance of an equipment in a semiconductor process or a display process is disclosed. The monitoring device comprises a protection layer, a board disposed in an internal space of the protection layer, and at least one electrical element disposed on the board. Here, the electrical element includes one or more sensors, the monitoring device monitors an object to be monitored by measuring at least one of a temperature, a slope, a light, a vibration, a voltage, current, a power or a pressure of the object located outside the monitoring device and a distance between the object and another element, an intaglio structure or an embossing structure is formed to the board, material with different characteristics from the board is filled in the intaglio structure or the embossing structure is formed of material with different characteristics from the board.

Abstract: This document describes implantable medical devices and methods of using such devices. The implantable medical devices include a cardiac lead sized for insertion in a cardiac cavity, the cardiac lead having a distal end and a proximal end and a lead body extending therebetween, a heat exchange module disposed at the distal end of the lead body, the heat exchange module comprising an enclosure having a first surface and a second surface, and one or more temperature sensors located within the enclosure.

Abstract: An atrial flutter identification method includes placing a catheter comprising multiple electrodes in a coronary sinus (CS) of a heart of a patient, so that some of the electrodes overlap a left atrium (LA) of the heart and some of the electrodes overlap a right atrium (RA) of the heart. Intra cardiac (IC) electrophysiological (EP) signals are acquired with the electrodes. Respective signal-stability measures are estimated over the signals acquired by the electrodes overlapping the LA and over the signals acquired by the electrodes overlapping the RA. When one of the signal-stability measures is above a first threshold while the other of the signal-stability measures is below a second threshold, an atrium is indicated, that corresponds to a highest among the signal-stability measures as a source of atrial flutter.

Abstract: A micromechanical electrically actuable switch. The switch has a first relay with a first operating contact, and a second relay with a second operating contact. The first operating contact and the second operating contact are arranged in series in a common load path. The switch further includes a detection device for detecting a switching state of the first operating contact, and a control circuit for registering the switching state of the first operating contact and for switching on the electrically actuable switch. The control circuit is configured, upon a switch-on signal, to switch on the first relay and the second relay in a first case, in which the switching state of the first operating contact is “open”, and to not switch on at least the second relay in a second case, in which the switching state of the first operating contact is “closed”.

Abstract: A system that executes a process for mapping cardiac fibrillation and optimizing ablation treatments. The process, in some embodiments, includes: positioning a two dimensional electrode array to several locations in a patient's heart and at each location, obtaining a conduction velocity and a cycle length measurement from at least two local signals in response to electrical activity in the cardiac tissue. In some embodiments, a regional wavelength is calculated by multiplying the local conduction velocity with the local minimum cycle length. The system can then create a wavelength distribution map that identifies the location of the drivers in the heart. In certain embodiments, the system uses variability of conduction velocity and cycle length in an area to determine the driver type. In some embodiments, the system calculates average distance of drivers to non-conductive tissue boundaries. The system then selects ablation placements that maximize treatment efficacy while minimizing tissue damage.

Abstract: Techniques for obtaining impedance data to provide an early warning for heart failure decompensation are described. An example device may be configured to measure subcutaneous impedance values, and increment an impedance score. In some examples, the device may use an adaptive threshold and fluid index in incrementing the impedance score. In some examples, the impedance score is compared to a threshold to determine a heart failure status of a patient. In some examples, may cause resets in fluid index values and/or determine positions or orientations of the device when determining the impedance score.

Abstract: A medical device is configured to determine tachyarrhythmia evidence in a cardiac signal segment received from a cardiac electrical signal sensed during a pacing escape interval started to schedule a pending cardiac pacing pulse. The medical device may delay the pending cardiac pacing pulse in response to determining the tachyarrhythmia evidence during the pacing escape interval.

Abstract: A cardiac treatment device, including: stimulation circuitry configured to generate a non-excitatory electrical signal which, when applied to ventricular tissue during a ventricular refractory period thereof improves a condition of heart failure in human patients; atrial arrhythmia detection circuitry; and decision circuitry which controls the stimulation circuitry to delivery said signal, also when said atrial arrhythmia detection circuitry detects an atrial arrhythmia.

Abstract: A method of delivering neurostimulation therapy to a patient from an implantable medical device is provided. The method includes delivering, by the implantable medical device, the neurostimulation therapy to the patient. The method further includes determining, by the implantable medical device, that the patient has received a defibrillation shock from a defibrillation device. The method further includes adjusting, by the implantable medical device, the neurostimulation therapy based on determining that the patient has received the defibrillation shock.

Abstract: Provided is a biological information acquisition system capable of acquiring an electric parameter and biological information that are more accurate. A biological information acquisition system 200 includes a flexible electrode sheet 100 having multiple electrodes 30 arranged in an array, an electrode selector that acquires an electric parameter from the multiple electrodes 30 in a state in which the electrode sheet 100 is arranged along a biological body 300 such that the multiple electrodes 30 do not contact the biological body 300 to select the electrodes 30 to be used for acquisition of biological information based on the acquired electric parameter, and a biological information acquirer that acquires the biological information from the electrodes 30 selected by the electrode selector in a state in which the electrode sheet 100 is arranged along the biological body 300 such that the multiple electrodes 30 do not contact the biological body 300.

Abstract: A system includes an implantable medical device (IMD) and processing circuitry. The IMD includes sensing circuitry configured to sense cardiac electrical signals of a patient, and therapy delivery circuitry configured to deliver demand cardiac pacing to a heart of the patient based on the cardiac electrical signals. The processing circuitry is configured to: determine, for each of a plurality of time units, based on the cardiac electrical signals and the delivery of demand cardiac pacing during the time units, a plurality of metrics indicative of a need for continued delivery of demand cardiac pacing to the heart of the patient. The plurality of metrics includes a metric associated with a duration of one or more pacing episodes during the time unit. The processing circuitry is further configured to generate a graphical representation of the plurality of metrics of the plurality of time units for presentation to a user.

Abstract: A computer-implemented method for generating and displaying a graphical user interface (GUI) is disclosed. The method includes displaying, via the GUI, a real-time video received from a camera disposed within an ablation catheter. The method further includes displaying, via the GUI, a graphical representation of a plurality of electrodes of the ablation catheter.

Abstract: A method, computer program product, and infusion pump assembly for administering a sequential, multi-part, infusion event, wherein the sequential, multi-part, infusion event includes a plurality of discrete infusion events. If a one-time infusion event is available to be administered, the administration of at least a portion of the plurality of discrete infusion events included within the sequential, multi-part, infusion event is delayed. The one-time infusion event is administered.

Abstract: A system for treating disordered breathing of a human being includes an implantable transvenous stimulation lead having at least one stimulation electrode and a sensor configured to detect activity level of the human being. The system includes an energy source, a pulse generator and circuitry, the circuitry operative to receive a signal indicative of the activity level of the human being from the sensor, wherein the circuitry is configured to cause the energy source and the pulse generator to deliver spaced apart stimulation signals to the at least one stimulation electrode while the activity level of the human being is sufficiently low to be indicative of sleep. Spaced apart stimulation pulses from the electrode are configured to extend a duration of a time of at least one breath being defined as the time from an onset of inhalation to the onset of inhalation of a successive breath.

Abstract: Provided is an electrocardiogram lead guide system. The electrocardiogram lead guide system may include: an electrocardiograph attached to a part of a body of a patient and acquiring posture information and electrocardiogram signals using a plurality of sensors; and a user terminal providing guide information for guiding the attachment direction of the electrocardiograph based on the posture information.

Abstract: Class imbalance in a training dataset may negatively impact the accuracy of a machine-learning model in classifying rare events that are underrepresented in the training dataset. Training datasets comprising time-series data present a unique challenge. Accordingly, resampling techniques for up-sampling and/or down-sampling a training dataset of time series are disclosed. The up-sampling may respect the temporal correlation of time samples in the time series, while generating synthetic time series that mimic the feature values of time series belonging to the minority class. Down-sampling may be used to fine-tune the ratio of time series belonging to the minority class to the time series belonging to the majority class.

Abstract: An exemplary tissue detection and location identification apparatus can include, for example, a first electrically conductive layer at least partially (e.g., circumferentially) surrounding a lumen, an insulating layer at least partially (e.g., circumferentially) surrounding the first electrically conductive layer, and a second electrically conductive layer circumferentially surrounding the insulating layer, where the insulating layer can electrically isolate the first electrically conductive layer from the second electrically conductive layer. A further insulating layer can be included which can at least partially surrounding the second electrically conductive layer.

Abstract: This disclosure relates to an implantable electric circuit (300) for medical stimulation The circuit comprises a plurality of capacitors (301) and a network of resistors (302). Each of the plurality of capacitors (301) is configured to couple radio frequency energy from one of a plurality of electrically conductive filaments (5) of a lead to the network of resistors (302). Further, the network of resistors (302) is configured to connect the plurality of capacitors (301) together to dissipate the radio frequency energy between the plurality of electrically conductive filaments. The network of resistors dissipates the energy between the filaments, which reduces negative impacts for the patient when subjected to MRI imaging. Further, no ground is required and as a result, the circuit can be placed into a header of an implantable pulse generator or into the lead itself.

Abstract: Systems and methods are described herein for detecting efficiency of pacing using external cardiac signals. A representative electrical signal morphology of the cardiac signals may be determined based on the plurality of electrical signals, and an efficacy of left bundle branch (LBB) engagement determined based on the representative electrical signal morphology.

Abstract: An electrical connector for high speed and high performance applications requiring protection against electrostatic discharge (ESD). In embodiments, the electrical connector includes a dielectric housing having a plurality of cavities descending from a top surface of the housing, a copper ground plate mounted atop or proximal to the top surface having a plurality of perforations corresponding in number and position to the plurality of cavities, and a plurality of electrical contacts each positioned at depth in one of the cavities such that the electrical contacts are recessed relative to the copper ground plate such that, in use of the electrical connector, a shortest path of ESD is to the copper ground plate and not any of the electrical contacts.

Abstract: Disclosed in the present invention is a pacing device for preventing occurrence of atrial fibrillation following premature atrial contraction, including: adjusting values of the number M of atrial events and the number N of premature atrial contraction events to control a pacing control process for preventing the occurrence of atrial fibrillation following premature atrial contraction to take place after a single or more than one premature atrial contraction events, and on the basis of a current p-p? interval, an atrial safe pacing interval and an average atrial interval, setting a smooth transition pacing sequence. The smooth transition pacing sequence avoids atrial compensation intervals caused by the premature atrial contraction and avoids occurrence of a “short-long-short” sequence.

Abstract: An implantable medical device comprises a control circuit and a memory. The memory is operably coupled to the control circuit. The memory comprises instructions that, when executed by the control circuit, cause the control circuit to monitor an output of at least one comparator, the output of the at least one comparator being responsive to a cardiac signal of a patient. The instructions further cause the control circuit to automatically adjust a gain level applied to the cardiac signal over time based on the monitored output of the at least one comparator.

Abstract: A medical device is configured to set a post-atrial time interval in response to an atrial event and generate an event time signal in response to a ventricular electrical signal crossing an R-wave sensing threshold during the post-atrial time interval. The device accumulates oversensing evidence in response to the event time signal and adjusts a ventricular sensing control parameter based on the accumulated oversensing evidence in some examples.

Abstract: The present technology generally includes devices, systems, and methods for providing electrical stimulation to the left ventricle of a human heart in a patient suffering from Left Bundle Branch Block (LBBB). In particular, the present technology includes an implantable receiver-stimulator and an implantable controller-transmitter for leadless electrical stimulation of the heart. The receiver-stimulator can include one or more sensors capable of detecting the electrical conduction of the heart and the receiver-stimulator can be configured to pace the stimulation of the left ventricle based off the sensed electrical conduction to achieve synchronization of the left and right ventricles.

Abstract: Devices, systems and methods for non-invasive modulation of the baroreflex system of a patient. In embodiments, the present disclosure may be used to measure and monitor baroreflex function for diagnostic purposes in patients acutely or chronically to inform and guide medical treatment, assess disease severity, or assess morbidity/mortality risk. In embodiments, the present disclosure may be used to provide non-invasive baroreflex activation therapy acutely or chronically to treat a variety of disease conditions through rebalancing of the sympathetic and parasympathetic limbs of the autonomic nervous system and their connections to higher brain centers.

Abstract: Disclosed is an implantable device for controllably delivering a neural stimulus. The device comprises: a plurality of electrodes including one or more stimulus electrodes and one or more sense electrodes; a stimulus source configured to provide a neural stimulus to be delivered via the one or more stimulus electrodes to a neural pathway of a patient in order to evoke a neural response on the neural pathway; measurement circuitry configured to process a signal window sensed at the one or more sense electrodes subsequent to the delivered neural stimulus, the sensed signal window including an evoked neural response; and a control unit.

Abstract: Devices and methods of use for introduction and implantation of an electrode as part of a minimally invasive technique. An implantable baroreflex activation system includes a control system having an implantable housing, an electrical lead, attachable to the control system, and an electrode structure. The electrode structure is near one end of the electrical lead, and includes a monopolar electrode, a backing material having an effective surface area larger than the electrode, and a releasable pivotable interface to mate with an implant tool. The electrode is configured for implantation on an outer surface of a blood vessel and the control system is programmed to deliver a baroreflex therapy via the monopolar electrode to a baroreceptor within a wall of the blood vessel.

Abstract: Devices, systems, and methods configured to treat disease using electrical stimulation and therapeutic agents are disclosed herein. In some embodiments, a device of the present technology comprises a first elongated shaft configured to deliver supplemental nutrition to a patient suffering from dysphagia and a second elongated shaft configured to slidably receive the first elongated shaft. The second elongated shaft can include one or more conductive elements configured to deliver electrical stimulation to nerves at a first treatment site in a pharynx of the patient. In some embodiments, the second elongated shaft includes one or more therapeutic elements carrying a therapeutic agent configured to be positioned at or adjacent a second treatment site with a pooled secretion in the patient's pharynx. The therapeutic agent can be configured to prevent or inhibit colonization of the pooled secretion by one or more pathogens.

Abstract: An implantable medical device for stimulating a heart, includes a stimulation electrode configured to stimulate a first cardiac region of the heart, and a detection unit configured to detect an intracardiac electrogram at a second cardiac region (ventricle) of the heart. In operation, the device: delivers a stimulation pulse to the heart; evaluates a time and at least one morphologic parameter of a responsive signal of an intracardiac electrogram, wherein the at least one morphologic parameter is chosen from: an absolute value of the signal amplitude, a width of the signal, a positive, negative and/or total area under at least a part of the signal, and a number of occurrences and/or time of occurrence of zero crossings of the signal; and identifies a dislocation of the stimulation electrode if the time of the signal is below a first threshold value and the morphologic parameter exceeds a further threshold value.

Abstract: A neuromodulation catheter in accordance with a particular embodiment includes an elongate shaft and a neuromodulation element operably connected to the shaft. The shaft includes a proximal hypotube segment at its proximal end portion and a jacket disposed around at least a portion of an outer surface of the hypotube segment. The jacket may be made at least partially of a polymer blend including polyether block amide and polysiloxane. The neuromodulation element includes a distal hypotube segment and a tubular jacket disposed around at least a portion of an outer surface of the distal hypotube segment. The jacket has reduced-diameter segments spaced apart along its longitudinal axis. The neuromodulation element further includes band electrodes respectively seated in the reduced-diameter segments and respectively forming closed loops extending circumferentially around the jacket.

Abstract: An example device includes a memory configured to store representations of sensed signals. The example device includes processing circuitry coupled to the memory, the processing circuitry being configured to read or write the representations of the sensed signals in the memory. The example device includes sensing circuitry coupled to the processing circuitry, the sensing circuitry being configured to sense signals indicative of a physiological condition of a patient via a plurality of electrodes and to output to the processor circuitry the representations of the sensed signals. The sensing circuitry includes a switched capacitor charge pump configured to amplify the sensed signals to generate amplified signals.

Abstract: A medical device is configured to identify a first group of cardiac events, determine a cardiac event interval based on the first group of cardiac events and determine whether the cardiac event interval is less than a threshold interval or greater than the threshold interval. The medical device is configured to select a first blanking period duration if the cardiac event interval is less than the threshold interval or a second blanking period duration if the cardiac event interval is greater than the threshold interval.

Abstract: A system for providing electrocardiogram (ECG) information to a healthcare provider (HCP) is provided. The system includes a network interface configured to receive drug prescription information from a computing device associated with the HCP and ECG data from a medical device associated with a patient. The system also includes a memory configured to store the drug prescription information and the ECG data. The system can further a processor configured to select a period of time over which to review the received drug prescription information and the received ECG data, retrieve the received ECG data for the selected period of time, derive one or more ECG metrics including at least one heart rate parameter, and generate a graphical representation indicating a trend in the one or more ECG metrics and a relationship between the one or more ECG metrics and the drug prescription information.

Abstract: This disclosure relates to electrophysiology cardiac ablation devices, methods, and systems. In particular, this disclosure relates to devices, methods, and systems that create a reversible non-ablative blockade of cardiac tissue, test the cardiac tissue, and ablate the cardiac tissue.

Abstract: A delivery device (10) for percutaneously implanting a medical implant (1) in tissue of a patient includes a delivery sheath (12, 13, 53, 61, 62, 65, 66) adapted to at least partially surround the medical implant and carry the medical implant for percutaneous delivery in the patient's tissue. The delivery device also includes a power delivery system (37) adapted to provide electric power to the medical implant within the delivery sheath.

Abstract: Pulse pattern detecting circuitry for use with a fractional voltage multiplier of a neurostimulation system is provided. The pulse pattern detecting circuitry is configured to detect an initial overlap of a repeating pulse pattern, wherein the repeating pulse pattern is generated by a plurality of pulse engines that generate pulses at different frequencies, the initial overlap occurring when pulses generated by each of the plurality of pulse engines occur simultaneously, detect a subsequent overlap of the repeating pulse pattern, the subsequent overlap of the pulse pattern occurring when pulses generated by each of the plurality of pulse engines again occur simultaneously, detect a plurality of events between the initial overlap and the subsequent overlap, each event corresponding to at least one of the plurality of pulse engines generating a pulse, and record a voltage multiplier setting for each of the plurality of detected events.

Abstract: An intravascular data analysis system to assess a blood vessel includes: an interface system configured to receive intravascular pressure data including a plurality of distal pressure (Pd) values measured by an intravascular data collection probe and a plurality of proximal pressure (Pa) values; a display system; one or more memory storage devices includes instructions; and a processor in communication with the interface system, the display system, and the one or more memory storage devices. The processor is configured to execute the instructions to: determine a plurality of Pd/Pa ratios based on the plurality of distal pressure (Pd) values and the plurality of proximal pressure (Pa) values, filter the plurality of Pd/Pa ratios using a filter having a time constant TC in a range of 1% to 50% of a heart cycle length, and control the display system to generate a plot based on the plurality of Pd/Pa ratios.

Abstract: A medical device processor is configured to receive a first cardiac electrical signal sensed from a first sensing electrode vector, receive a second cardiac electrical signal sensed from a second sensing electrode vector different than the first sensing electrode vector, and construct a third cardiac electrical signal from the first cardiac electrical signal and the second cardiac electrical signal. In some examples, the system determines sensed cardiac events according to at least one setting of a cardiac event sensing threshold control parameter from at least the third cardiac electrical signal and may determine at least one acceptable setting of a sensing control parameter based on the determined sensed cardiac events. The processor may generate an output representative of the determined sensed cardiac events.

Abstract: Described here are methods and apparatuses for removing a clot material from a patient. For example, an apparatus as described herein may include a flexible elongate body having a suction lumen, a first pair of sensors (e.g., electrodes), and a controller configured to identify a clot material based on signals from the first pair of sensors.

Abstract: Implantable electrodes with power delivery wearable for treating sleep apnea, and associated systems and methods are disclosed herein. A representative system includes non-implantable signal generator worn by the patient and having an antenna that directs a mid-field RF power signal to an implanted electrode. The implanted electrode in turn directs a lower frequency signal to a neural target, for example, the patient's hypoglossal nerve. Representative signal generators can have the form of a mouthpiece, a collar or other wearable, and/or a skin-mounted patch.

Abstract: The invention relates to a device for assisting a first aider with a cardiopulmonary resuscitation of a person suffering cardiac arrest, comprising a transport housing (1), in which a sensor apparatus (4) and two adhesive electrodes (2), which are or can be connected to the sensor apparatus (4), can be stowed. The sensor apparatus (4) allows data to be acquired while the first-aid measures for resuscitation are performed. The sensor apparatus (4) comprises an adhesive (5) for attachment to the chest of the patient (3). The chest compressions, i.e. depth of compression and compression frequency, can be detected by means of a motion sensor. An interface for data transfer allows wireless communication with a mobile terminal (6). Furthermore, the sensor apparatus (4) contains a high-voltage store so that, after connection to the adhesive electrodes (2), a single defibrillation shock can be delivered.

Abstract: System and method for determining real-world effectiveness of various prescribed medications. Here a variety of different types of patient pulse wave measurements (e.g., blood pressure, pulse oximeter, ECG) and other physiological measurements are obtained. This actual data is compared to calculated measurements that would be expected based on various patient baseline measurements in the absence of medication, schedule of medications, and impact of medications the various patient baseline measurements. If the actual data meets expectations, then the medication is likely acting as anticipated. Depending on which types of data do not meet expectations, problems with one or more previously described medications may be reported.

Abstract: A method and medical device for detecting a cardiac event that includes sensing cardiac signals from a plurality of electrodes, the plurality of electrodes forming a first sensing vector and a second sensing vector, identifying the cardiac event as one of a shockable event and a non-shockable event in response to first processing of a first interval sensed along the first sensing vector during a predetermined sensing window and a second interval simultaneously sensed along the second sensing vector, performing second processing of the first interval and the second interval, different from the first processing, in response to the cardiac event being identified as a shockable event, and determining whether to delay identifying the cardiac event being shockable in response to the second processing of the first interval and the second interval.

Abstract: An implantable medical device system is configured to generate signals and deliver the signals to a heart of a patient. The implantable medical device system includes electronic circuitry configured to deliver cardiac pacing, couplings for an implantable medical lead receptacle, at least some of the couplings electrically connected with the electronic circuitry, a polymeric enclosure having the electronic circuitry contained therein, the polymeric enclosure formed of polymeric material filled around the electronic circuitry and couplings and forming the implantable medical lead receptacle. The implantable medical device may include a first cavity filled with a first material and a second cavity filled with a second material, and the first material is different than the second material.

Abstract: A medical device is configured to determine a rate smoothing pacing interval based on at a ventricular cycle length ending with a ventricular pacing pulse and determine a post-sense ventricular pacing interval based on a ventricular cycle length ending with a sensed ventricular event signal. The medical device may be configured to start a ventricular pacing interval set to the post-sense ventricular pacing interval in response to the sensed ventricular event signal and generate a ventricular pacing pulse in response to the expiration of the post-sense ventricular pacing interval.

Abstract: A stretch-measurement probe includes an elongate outer sleeve, expansion feature associated with a distal portion of the outer sleeve, and an elongate inner rod disposed at least partially within the outer sleeve. The expansion feature is configured to allow a longitudinal distance between a proximal end of the outer sleeve and the distal end of the outer sleeve to be varied.

Abstract: A medical device is configured to receive a cardiac signal and determine a morphology matching score from the cardiac signal and a capture detection morphology template that corresponds to a first type of cardiac pacing capture that includes capture of at least a first portion of the His-Purkinje system. The device is configured to detect a second type of cardiac pacing capture in response to the morphology matching score being less than the first match threshold. The second type of cardiac pacing capture is different than the first type of cardiac pacing capture and may include capture of the ventricular myocardium and/or a second portion of the His-Purkinje system different than the first portion.

Abstract: An implantable medical device comprises a sensing module configured to obtain electrical signals from one or more electrodes and a control module configured to process the electrical signals from the sensing module in accordance with a tachyarrhythmia detection algorithm to monitor for a tachyarrhythmia. The control module detects initiation of a pacing train delivered by a second implantable medical device, determines a type of the detected pacing train, and modifies the tachyarrhythmia detection algorithm based on the type of the detected pacing train.

Abstract: A pacemaker has a housing and a therapy delivery circuit enclosed by the housing for generating pacing pulses for delivery to a patient's heart. An electrically insulative distal member is coupled directly to the housing and at least one non-tissue piercing cathode electrode is coupled directly to the insulative distal member. A tissue piercing electrode extends away from the housing.