Abstract: The present disclosure belongs to the technical field of artificial cardiac pacemakers, and particularly relates to a leadless left-bundle-branch pacemaker. The leadless left-bundle-branch pacemaker comprises a case and an implant core, wherein the implant core is coaxially arranged inside the case, and a head of the implant core can be rotated out from the inside of the case; the implant core has an implant end that can be rotated out from the inside of the case, and the length of the implant end rotated out from the inside of the case is greater than 10 mm; and an end of the case corresponding to the implant end is provided with a fixing end for fixing the pacemaker.

Abstract: Disclosed is an area array micro-needle structure, including a positioning partition plate and at least one micro-needle assembly. The positioning partition plate includes at least two comb structure members stacked to form a plurality of micro-needle holes for a body electrode of a micro-needle to pass through. The positioning partition plate can provide the positioning guiding and fixing effects when the area array micro-needles are implanted, so that accurate implantation of the micro-needles is achieved; the micro-needles can be pulled out after being completely implanted, without damaging human organs and tissues.

Abstract: Implementations described herein relate to a two-stage emergency data storing operation. In some implementations, a memory device may detect a power loss notification signal that indicates a power loss condition of the memory device. The memory device may read a mode register bit of the memory device that indicates to perform a data storing operation that includes a first data storing stage and a second data storing stage. The first data storing stage may include storing data associated with the memory device prior to the memory device experiencing a power loss, and the second data storing stage may include storing data and metadata associated with the memory device prior to the memory device experiencing the power loss. The memory device may initiate the data storing operation and may selectively acknowledge the power loss condition based on completing the first data storing stage or the second data storing stage.

Abstract: A medical lead includes a lead body, a lead body helix extending from a distal end of the lead body, wherein the lead body helix is configured to anchor to a patient tissue, and, a cable within the lead body, the cable including a cable conductor, a cable electrode proximate a distal end of the cable conductor, and a cable helix with a blunt tip at a distal end of the cable. The cable is slidable within the lead body to extend and retract the cable electrode along a trajectory extending from the distal end of the lead body.

Abstract: Systems and methods for designing patient-specific medical devices are described herein. In some embodiments, a method includes obtaining patient data that includes image data and kinematic data of a patient's spine. A virtual model of the patient's spine is generated and can be manipulated until a target anatomical configuration is achieved. A patient-specific implant can then be designed based at least in part on the target anatomical configuration and the kinematics such that, when the patient-specific implant is implanted in the patient, the patient-specific implant provides the target anatomical correction while maintaining or improving the kinematics of the patient's spine.

Abstract: An electrode device for wrapping a vessel in the body according to an embodiment of the present invention comprise an electrode part that surrounds the vessel and denervates or modulates at least some nerves of the vessel; and a guide part that guides movement of the electrode part, wherein the electrode part includes: a first layer that is bent in order for the electrode part to be wound around the vessel; a second layer that is placed on the first layer and is bent in order for the electrode part to be wound in close contact with the vessel; an electrode that is placed on the second layer and denervates or modulates at least some nerves of the vessel with energy from an energy source generator.

Abstract: Assemblies and methods provide for implantation of multiple medical leads to a defined space within the body, such as the epidural space, through a single entry. A catheter having multiple lumens or alternatively a single oblong lumen may be used. A distal end of the catheter enters the defined space through the single entry such that the distal ends of the multiple lumens or the oblong lumen are present in the defined space. Medical leads are introduced through the multiple lumens or the oblong lumen into the defined space. In some cases, the distal end of the catheter may be deflectable to direct the medical leads within the defined space. In other cases, sheaths may be present within each lumen of the catheter where the sheaths may be extended into the defined space and deflect to direct the medical leads that are being passed through a lumen of the sheaths.

Abstract: Sense amplifier circuits particularly useful in sensing neural responses in an Implantable Pulse Generator (IPG) are disclosed. The IPG includes a plurality of electrodes, with one selected as a sensing electrode and another selected as a reference to differentially sense the neural response in a manner that subtracts a common mode voltage (e.g., stimulation artifact) from the measurement. The circuits include a differential amplifier which receives the selected electrodes at its inputs, and comparator circuitries to assess each differential amplifier input to determine whether it is of a magnitude that is consistent with the differential amplifier's input requirements. Based on these determinations, an enable signal is generated which informs whether the output of the differential amplifier validly provides the neural response at any point in time.

Abstract: Hip replacement prosthesis are provided, comprising a femoral stem, a femoral head coupled to the femoral stem, and an acetabular assembly coupled to the femoral head, and a plurality of sensors coupled to at least of the femoral stem, femoral head, and acetabular assembly.

Abstract: Neural interfaces with the peripheral nervous system have been developed to provide a direct communication pathway between peripheral nerves and prosthetic limbs. Described herein is a method of making a microchannel integrated neural interface device comprising a plurality of hollow cylindrical electrodes in a PDMS scaffold, which can control the reinnervated muscles and interpret neurological signals. The acquired bioelectrical signals can be used for the interpretation of mind and create a neural map.

Abstract: A strain sensor that includes a first atomic layer deposition layer, a flexible molecular layer deposition layer on top of the first atomic layer deposition layer, and a second atomic layer deposition layer on top of the molecular layer deposition layer.

Abstract: Embodiments relate to an implantable device for detecting leakage of matter from a mammalian lumen, the device comprising a mesh structure that is attachable to a lumen of a mammalian. The mesh structure comprises a material or a material composition that is electrically conductive and which is measurably responsive in terms of its electrical conductivity when being subjected to leakage of matter from the lumen.

Abstract: The present disclosure discusses a method of manufacturing an implantable neural electrode. The method includes cutting a metal layer to form a plurality of electrode sites, contact pads and metal traces connecting the electrode sites to the contact pads. A first silicone layer including a mesh is formed and coupled to the metal layer. A second silicone layer is formed and laminated to the first silicone layer coupled with the metal layer. Holes are formed in the first or second silicone layer exposing the contact pads and electrode sites. Wires are welded to the exposed contact pads and a third layer of silicone is overmolded over the contact pads and wires.

Abstract: A microelectrode comprises an oblong electrically conducting electrode body covered by distal and proximal sections of a layer of insulating material except for an annular contact section disposed between them, a blunt distal bulge at the distal end of a radial extension substantially greater than that of the proximal section of non-conducting material. For implantation into soft tissue the microelectrode is provided with a support of a material dissolvable in body fluid. Also disclosed is a set of microelectrodes sharing such support, a method of manufacture of the microelectrode and the set, and uses of the microelectrode and the set.

Abstract: Systems and methods for calibrating an orientation of an implantable device in a patient is described. An exemplary system includes a calibration circuit that can receive acceleration information sensed from an implantable medical device (IMD) implanted in a patient, and receive reference acceleration information sensed from a reference device associated with the patient. The acceleration information and the reference acceleration information are acquired when the patient assumes a first posture or in a first position. The calibration circuit determines a spatial relationship between an orientation of the IMD and a reference orientation of the reference device using the received acceleration information and the received reference acceleration information, and calibrate subsequent acceleration information sensed from the IMD using the determined spatial relationship to correct for the orientation of the IMD.

Abstract: VfA cardiac therapy uses an implantable medical device or system. The implantable medical device includes a tissue-piercing electrode implanted in the basal and/or septal region of the left ventricular myocardium of the patient's heart from the triangle of Koch region of the right atrium through the right atrial endocardium and central fibrous body. The device may include a right atrial electrode, a right atrial motion detector, or both. The device may be implanted completely within the patient's heart or may use one or more leads to implant electrodes in the patient's heart. The device may be used to provide cardiac therapy, including single or multiple chamber pacing, atrioventricular synchronous pacing, asynchronous pacing, triggered pacing, cardiac resynchronization pacing, or tachycardia-related therapy. A separate medical device may be used to provide some functionality for cardiac therapy, such as sensing, pacing, or shock therapy.

Abstract: An implantable light generation arrangement for an optical or optical/electrical stimulation system includes a light source having an emission surface, wherein the light source is configured to generate light and emit the light from the emission surface; an optical waveguide having a first end and a core; a ball lens disposed between the light source and the optical waveguide and configured to receive the light emitted from the light source and direct the light onto the core at the first end of the optical waveguide; and a fixture holding the light source, optical waveguide, and ball lens in a fixed arrangement.

Abstract: Nanomaterial epidermal sensors can be adhered to the skin and worn comfortably and inconspicuously for days to allow for repeated biometric sensing. The nanomaterial epidermal sensors may be comprised of a monolayer of graphene coating a flexible polymer substrate. Various nanomaterial epidermal sensors may be quickly fabricated using a cost-efficient “cut-and-paste” method on transfer paper and can be adhered directly to skin without tape or adhesive, much like a temporary-tattoo. The nanomaterial epidermal sensors may be optically transparent and may be used to measure an electrocardiogram (ECG), an electroencephalogram (EEG) or an electromyogram (EMG) with a signal-to-noise ratio that is comparable to conventional electrodes. In addition, the nanomaterial epidermal sensors may be used to measure other parameters, such as skin temperature or skin hydration.

Abstract: The present invention discloses a transient sensor using molybdenum disulfide and a method of manufacturing the same. According to one embodiment of the present invention, the transient sensor using molybdenum disulfide includes a water-soluble substrate; a water-soluble insulating layer deposited on the water-soluble substrate; an electrode layer formed of any one of molybdenum (Mo) and magnesium (Mg) and formed on the water-soluble insulating layer; and a channel layer formed of molybdenum disulfide and formed on the water-soluble insulating layer to be connected to the electrode layer. In addition, when the transient sensor is inserted into living matter, the transient sensor can be dissolved within a critical time in the living matter.

Abstract: A stimulation system comprising: an implantable lead having a proximal end and a distal end, and at least one electrode along its distal end; an implantable neuromodulation stimulator disposed along the proximal end of the implantable lead; and an external device comprising a battery, a transmitter, and an antenna. The implantable lead is integral to the implantable neuromodulation stimulator. Methods of providing stimulation are also described.

Abstract: Disclosed herein are embodiments of methods of inspection and manufacture of flexible printed circuit boards and flexible sensor sheets, and apparatuses such as wound dressing components utilizing the same. The methods can comprise applying a coating material to a flexible printed circuit board, wherein the coating material comprises a material that will fluoresce when exposed to UV or visible light and the flexible printed circuit board comprises one or more electronic components. The coated flexible printed circuit board can be positioned under UV or visible light to cause the coating material to fluoresce.

Abstract: An insertion device configured to implant a first medical device and a second medical device in a user. The first medical device may be a fluid delivery cannula configured to deliver a fluid (e.g., insulin) to the user. The second medical device may be an analyte sensor (e.g., a glucose sensor) configured to detect a physiological characteristic of the user (e.g., a glucose level). The insertion device may be configured to be worn by the user. The insertion device includes a first linkage assembly configured to extend and retract a first insertion needle to implant the first medical device and a second linkage assembly configured to extend and retract a second insertion needle to implant the second medical device. The insertion device includes a user input device configured to cause the insertion device to initiate the implantation when activated by the user.

Abstract: A wiring board on which electronic components are mountable includes a stretchable portion having stretchability and having a first surface and a second surface opposite to the first surface, and an interconnection wire electrically connected to the electronic components mounted on the wiring board. The stretchable portion includes first regions lined up in each of a first direction and a second direction, a second region including first portions and second portions, and a third region surrounded by the second region. The first regions overlap the electronic components. The first portion extends from one of two first regions neighboring each other in the first direction to the other thereof. The second portion extends from one of two first regions neighboring each other in the second direction to the other thereof. The second region has a lower modulus of elasticity than the first region. The interconnection wire overlaps the second region.

Abstract: Disclosed herein are devices, systems, and methods for a continuous analyte sensor, such as a continuous glucose sensor. In certain embodiments disclosed herein, various in vivo properties of the sensor's surroundings can be measured. In some embodiments, the measured properties can be used to identify a physiological response or condition in the body. This information can then be used by a patient, doctor, or system to respond appropriately to the identified condition.

Abstract: A pumping structure comprises at least two membranes, at least two actuation chambers, one evaluation chamber comprising an opening to the outside of the pumping structure, and at least three electrodes. Each membrane is arranged between two electrodes in a vertical direction which is perpendicular to the main plane of extension of the pumping structure, each actuation chamber is arranged between one of the membranes and one of the electrodes in vertical direction, and each actuation chamber is connected to the evaluation chamber via a channel. Furthermore, a particle detector and a method for pumping are provided.

Abstract: Described herein is an implantable medical device that includes a body having one or more ultrasonic transducers configured to receive ultrasonic waves and convert energy from the ultrasonic waves into an electrical energy, two or more electrodes in electrical communication with the ultrasonic transducer, and a clip attached to the body that is configured to at least partially surround a nerve and/or a filamentous tissue and position the two or more electrodes in electrical communication with the nerve. In certain examples, the implantable medical device includes two ultrasonic transducers with orthogonal polarization axes. Also described herein are methods for treating incontinence in a subject by converting energy from ultrasonic waves into an electrical energy that powers a full implanted medical device, and electrically stimulating a tibial nerve, a pudendal nerve, or a sacral nerve, or a branch thereof, using the fully implanted medical device.

Abstract: The invention is a medical implant which is a wrap-around cuff comprising a flexible, biocompatible, film carrier substrate, that has a carrier substrate region which is wrapped around a wrap axis to form a tube. The invention has a protective structure directly or indirectly attached to the carrier substrate, which can be transformed from a first, open state into a second closed state that encloses the carrier substrate region that is wrapped to form a tube at least axially around a wrapping axis extending in the peripheral direction of the tube.

Abstract: ElectroCorticoGraphy (ECoG) sensors and uses are disclosed. These ECoG arrays, systems, and processes may be operable or configured to: i) simultaneously record neural signals while providing stimulation on specific portions of the cortex using a user-guided stimulator; ii) acquire neural signals over a large cortex area; iii) provide individual or group stimulation while concurrently receiving neural feedback; and/or iv) acquire neural signals at a setting remote from the neural source using wireless or other communication techniques.

Abstract: A system for optical spectroscopy through a probe implanted in a tissue is provided. The system includes a light collecting probe comprising a waveguide formed by a single optical fiber and having a proximal end and a distal end, the proximal end being formed with a taper along which at least one optical window is positioned, wherein light entering at an axial section of the taper generates a specific subset of guided modes defined by the diameter of the single optical fiber at the axial section, the guided modes propagating toward the distal end of the waveguide and generating an output at the distal end of the waveguide; a demultiplexer configured to receive outputs provided by the light collecting probe and discriminate the outputs based on their modal content of origin; and a detector configured to detect the discriminated outputs.

Abstract: An implantable medical device includes an electrically conductive first housing, a conductive feedthrough extending through the first housing, electronic circuitry positioned within the first housing, a device electrode, and a second housing. The electronic circuitry is electrically coupled to the first housing and the feedthrough, and senses electrical signals of a patient and/or delivers electrical stimulation therapy to the patient via the first housing and the feedthrough. The device electrode is configured to electrically connect with tissue and/or a fluid at a target site in the patient. A lead connector is configured to connect to a proximal end of an implantable medical lead. The lead connector includes a first connector contact electrically coupled to the feedthrough and a second connector contact electrically coupled to the first housing.

Abstract: Disclosed here are devices, systems, and methods for continuous monitoring of biomarkers using a wearable, non-intrusive microneedle sensor patch platform. In some aspects, a wearable, non-intrusive microneedle sensor device includes a microneedle sensor unit couplable to an electronics unit, where the microneedle sensor unit comprises a substrate, an array of spiked microneedle structures configured as electrochemical sensor electrodes, an array of base structures that encase a lower portion of spiked microneedle structures, and electrical interconnections that electrically couple the electrodes to the electronics unit for processing of detectable signals associated with one or multiple biomarkers in a biofluid.

Abstract: A microelectromechanical device and method for neuroprosthetics comprises microactuators and microelectrodes. The microelectrodes are to be positioned in a nerve bundle and bonded with the microactuators through an interconnect. The position of each of the microactuators can be individually tuned through control signals so that the microelectrodes are implanted at desired positions in the nerve bundle. The control signals are transmitted to the microactuators and generated with a open-loop or closed-loop control scheme that uses signals acquired by the microelectrodes from the nerve bundle as feedback.

Abstract: A nerve stimulating apparatus includes a plurality of stimulating units configured to respectively apply stimuli to a plurality of nerve regions branching from a particular nerve region of a living body, and a stimulation timing controller configured to set generating timings of respectively generating the stimuli at the plurality of stimulating units. The stimulation timing controller sets the generating timings of generating the stimuli at the plurality of stimulating units based on response results of the particular nerve region, the response results being obtained in response to the stimuli that are respectively generated at the plurality of stimulating units and that are respectively applied to the plurality of nerve regions, and the response results being measured by a biometric information measuring apparatus that measures biometric information.

Abstract: A system and method for video assisted percutaneous needle cricothyrotomy and tracheostomy to assist physicians in quickly intubating patients suffering from respiratory distress when oral or nasal intubation is not possible or contraindicated. The system and method includes a display monitor, a percutaneous needle assembly including a connection hub having a syringe port for removably attaching a syringe, a needle port for attaching a hollow needle, and a stylet port in communication with the needle port for receiving a fiber optic stylet that extends through the hollow needle. The fiber optic stylet includes one or more illuminators, and a camera for capturing and transmitting anatomical images for display on the display monitor to visually assist physicians in locating a patient's trachea lumen. The fiber optic stylet is positioned within the trachea lumen, and used as a guide wire to insert a dilator and cannula for ventilating the patient.

Abstract: An extravascular neural interface is disclosed containing electrodes for neurostimulation of the vessel. The devices are housed in flexible substrates, each substrate having a spinal portion for routing leads/conductors into the device for connection to the electrodes. Extending from opposite sides of the spinal portion is a self-sizing inner flap that supports and positions the electrodes to be inward facing, i.e., extravascular designs, and one more rigid outer flap. The electrodes may be flexible multifilar coil electrodes.

Abstract: A device for pacemaker lead placement is disclosed. The device has a device tip having a tissue bite area, ferrule holders, and needle tips. The device also has a lead end rest at the distal end, with a pacemaker lead end situated on the lead end rest, the pacemaker lead end having first and second anchor suture holes. The device further has an anchor suture with ferrules at respective ends of the anchor suture, wherein the ferrules of the anchor suture are passed through the anchor suture holes and into communication with the ferrule holders. The device further has one or more tube guides configured to organize and manage sutures during a minimally invasive surgical procedure.

Abstract: A method and apparatus are disclosed for simultaneously providing a plurality of probe response signals indicative of electrical activity at a respective plurality of locations in a patient. The apparatus comprises a rigid needle shaft element comprising a piercing tip and a substrate supporting a plurality of electrode tracks, secured to the needle shaft element and extending along the shaft element away from the piercing tip. Each electrode track extends from a sensing end region arranged for providing a respective probe response signal responsive to localised electrical activity, along the region of the substrate, to a respective bond pad connection region. Recording surface regions of the plurality of electrode tracks are spaced apart in a plurality of substantially linear spaced apart configurations along the substrate.

Abstract: The present disclosure relates to a peripheral nerve electrode array that includes a first, second and third pair of electrodes spaced from each other along a longitudinal axis of the electrode array, the second pair of electrodes being located between the first and third pairs of electrodes. The present disclosure further relates to method for treating or preventing a chronic inflammatory condition in a human subject in need thereof, comprising providing to the human subject a therapeutically effective electrical stimulation of the anterior central abdominal vagus nerve or the posterior central abdominal vagus nerve, wherein the electrical stimulation is provided through two or more previously implanted electrodes at a site below the cardiac branches and above the hepatic-celiac branches of the nerve; and whereby the chronic inflammatory condition is prevented or treated in the human subject.

Abstract: Tissue-engineered electronic peripheral nerve interface (TEENI) devices, methods of using TEENI devices, and systems using TEENI devices are provided. In particular, TEENI devices include a support member having a length, at least one thread set comprising a plurality thread set arms having a plurality of electronic leads running through the thread set arms and being fully encapsulated within the support member, and a plurality of electrodes fixed to the plurality of thread set arms.

Abstract: Disclosed are an implantable flexible neural microelectrode comb, and a preparation method and implantation method therefor. The flexible neural microelectrode comb is mainly composed of a flexible substrate layer (1), a flexible insulation layer (2), and a metal connection wire layer (3) arranged between the flexible substrate layer (1) and the flexible insulation layer (2); the flexible neural microelectrode comb comprises a filament structure (4), a mesh structure (5), a plane structure (6) and a bonding pad area (7) connected in sequence; electrode sites (8) are arranged on the filament structure (4); bonding pads are arranged on the bonding pad area (7); the metal connection wire layer (3) is composed of metal connection wires connecting the electrode sites (8) and the bonding pads; and the flexible insulation layer (2) is not arranged on the surfaces of the electrode sites (8) and the bonding pads.

Abstract: A method for determining a threshold for spike detection in a noisy signal in real-time is provided. The method includes estimating a current variability of noise in the noisy signal according to a measured instantaneous value and a window of previous instantaneous values using a sigma-delta control loop, determining the threshold based on the estimated variability of the noise; and repeating the steps to update the estimate of the variability of the noise and adjust the threshold in real-time as the noisy signal changes. A non-transitory computer-readable storage medium for executing the method on a processing unit, and a low-power digital system implementing the method are also provided.

Abstract: A stationary dilator has one or more electrodes in the distal region that are rotatable around the longitudinal axis of the dilator. The one or more electrodes are operable to deliver electrical stimulation signals to tissue through which the dilator is passed. The stimulation signals can be used for determining nerve directionality and optionally nerve proximity during surgical procedures involving the presence of neural structures.

Abstract: A cuff electrode includes at least an array of electrodes to extend circumferentially about a nerve, and methods of making and using a cuff electrode.

Abstract: A flexible catheter has an ablation electrode disposed in its distal segment. The ablation electrode a cavity formed in its external surface, a microelectrode configured to fit into the cavity, a conductive wire lead connecting the microelectrode to receiving circuitry, and an electrical shield surrounding the wire lead. A power generator is connected to the ablation electrode and the electrical shield in a generator circuit. A back patch electrode adapted to contact with the subject is connected in the generator circuit. The microelectrodes can be active while energizing the ablation electrode.

Abstract: A microsensor and method of manufacture for a microsensor, comprising an array of filaments, wherein each filament of the array of filaments comprises a substrate and a conductive layer coupled to the substrate and configured to facilitate analyte detection. Each filament of the array of filaments can further comprise an insulating layer configured to isolate regions defined by the conductive layer for analyte detection, a sensing layer coupled to the conductive layer, configured to enable transduction of an ionic concentration to an electronic voltage, and a selective coating coupled to the sensing layer, configured to facilitate detection of specific target analytes/ions. The microsensor facilitates detection of at least one analyte present in a body fluid of a user interfacing with the microsensor.

Abstract: Aspects include high resolution brain-electronic interfaces and related methods. Aspects include forming a semiconductor circuit on a substrate, depositing a tensile stress layer on the circuit, and separating the semiconductor circuit from a portion of the silicon substrate. Aspects also include removing the tensile stress layer from the semiconductor circuit and transferring the semiconductor circuit to a biocompatible film.

Abstract: The present disclosure discusses a nerve cuff that includes a thin-film elastic mesh with an integrated array of electrodes. The nerve cuff can wrap around a human carotid artery or other tissue to stimulate the autonomic nervous system. The nerve cuff can include a housing that secures the mesh to the carotid artery or other tissue.

Abstract: In various examples, an apparatus is configured for targeted placement of a lead body within a patient. The lead body includes at least one distal electrode. The apparatus includes a needle including a lumen sized to accommodate the lead body within the lumen. A stylet is insertable within the needle, wherein at least one of the needle and the stylet includes at least one imageable marker corresponding in size, shape, and location to the at least one distal electrode of the lead body. The at least one imageable marker is configured to allow a user to determine placement within the patient of the at least one distal electrode of the lead body prior to implantation of the lead body within the patient.

Abstract: A microsensor and method of manufacture for a microsensor, comprising an array of filaments, wherein each filament of the array of filaments comprises a substrate and a conductive layer coupled to the substrate and configured to facilitate analyte detection. Each filament of the array of filaments can further comprise an insulating layer configured to isolate regions defined by the conductive layer for analyte detection, a sensing layer coupled to the conductive layer, configured to enable transduction of an ionic concentration to an electronic voltage, and a selective coating coupled to the sensing layer, configured to facilitate detection of specific target analytes/ions. The microsensor facilitates detection of at least one analyte present in a body fluid of a user interfacing with the microsensor.

Abstract: A device for obtaining an electrical conductance reading from a patient includes a sensor head for contacting a patient's skin. The device includes a primary conductive tip positioned on the sensor head and an ancillary conductive tip positioned on the sensor head to contact a different portion of the patient's skin than the primary conductive tip. The primary conductive tip and the ancillary conductive tip are electrically isolated from each other. The primary conductive tip and the ancillary conductive tip are configured to contact a patient's skin when the sensor head is placed against the patient's skin to obtain independent measurements of electrical conductance.