Abstract: Plaque type determination devices, systems, and methods. In at least one exemplary embodiment of a device for assessing composition of a plaque of the present disclosure, the device comprises an elongate body having a longitudinal axis and a distal end, a first excitation electrode and a second excitation electrode located along the longitudinal axis of the body near the distal end of the elongate body, and a first detection electrode and a second detection electrode along the longitudinal axis of the body and in between the first and second excitation electrodes, wherein when a current source in communication with at least one of the first excitation electrode and the second excitation electrode applies current thereto to facilitate measurement of two or more conductance values within a vessel containing at least part of the elongate body at or near a plaque site, a plaque type determination can be made based upon a calculation of tissue conductance using at least one of the two or more conductance values.

Abstract: A system comprising a biometric monitoring device including a housing including a platform to receive at least one foot of the user, a body weight sensor to generate body weight data, processing circuitry to calculate user weight data which corresponds to the user's weight, using the body weight data, and communication circuitry to: (a) receive user identification data which identifies the user or a portable activity monitoring device, and (b) transmit the user weight data to data storage associated with the user identification data. The system further includes the portable activity monitoring device including a housing having a physical size and shape that is adapted to couple to the user's body, a sensor to generate sensor data, and communication circuitry to receive physiologic data which is based on the user weight data, and processing circuitry to calculate activity data using the sensor data and physiologic data.

Abstract: A system and method for guiding a catheter or other medical device to a desired target destination within the vasculature of a patient via bioimpedance measurements is disclosed. The target destination in one embodiment includes placement of the catheter such that a distal tip thereof is disposed proximate the heart, e.g., the junction of the right atrium and superior vena cava. In one embodiment the method for guiding the catheter comprises introducing the catheter into a vessel of the patient, the catheter defining a lumen through which fluids can be infused into the vasculature of the patient. The catheter is advanced toward a target destination within the vasculature. A first impedance value based on intravascular detection of at least one electrical property related to a first tissue surface of the vessel is calculated to enable determination of the proximity of a distal end of the catheter to the target destination.

Abstract: 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.

Abstract: Embodiments of devices and methods for evaluating tissue are disclosed. In one embodiment, a method for measuring a characteristic of a tissue may include passing a current through the tissue, measuring a signal corresponding to the voltage resulting from passing the current through the tissue, analyzing current passed through the tissue and resulting voltage to determine the electrical characteristics of the tissue; and analyzing the electrical characteristics of the tissue to determine a status of the tissue.

Abstract: A volume of a patient can be mapped with a system operable to identify a plurality of locations and save a plurality of locations of a mapping instrument. The mapping instrument can include one or more electrodes that can sense a voltage that can be correlated to a three dimensional location of the electrode at the time of the sensing or measurement. Therefore, a map of a volume can be determined based upon the sensing of the plurality of points without the use of other imaging devices. An implantable medical device can then be navigated relative to the mapping data.

Abstract: A biofeedback system and method enables biofeedback training to be accomplished during normal interaction by an individual with the individual's environment, for example while reading, playing video games, watching TV, participating in sports activities, or at work. Physiologic data is processed and used to generate one or more control signals based on the physiologic data. The control signals may be proportional to a result of the data processing, or based on comparison of the processing results with at least one fixed or adaptive threshold. The control signal is supplied to a wearable device through which the individual receives sensory information from the individual's environment, and serves to interrupt or modify the sensory information.

Abstract: Impedance devices for obtaining conductance measurements within luminal organs. In at least one embodiment of an impedance device of the present disclosure, the device, comprises an elongated body and an detector positioned upon the elongated body, the detector comprising at least five electrodes and configured to obtain one or more conductance measurements generated using a first arrangement of four of the at least five electrodes and further configured to obtain one or more fluid velocity measurements using a second arrangement of four of the at least five electrodes when the elongated body is positioned within a fluid environment of a mammalian luminal organ, wherein the first arrangement is different from the second arrangement.

Abstract: A bioelectrical impedance measurement method is provided. A power signal and a frequency regulation signal for driving a measuring unit to perform bioelectrical impedance measurement are provided from a first sound channel output terminal and a second sound channel output terminal according to a measuring mode of a host device, and a signal measured and mixed is received by a microphone input terminal of the host device, and a bioelectrical impedance measurement result is analyzed and displayed by the host device.

Abstract: A method for performing an electrophysiological analysis implemented in a system includes: a series of electrodes to be placed on different regions of the human body; a DC voltage source controlled so as to produce DC voltage pulses; a switching circuit for selectively connecting the active electrodes to the voltage source, the active electrodes forming an anode and a cathode, and for connecting at least one other high-impedance passive electrode used to measure the potential reached by the body; and a measuring circuit for reading data representative of the current in the active electrodes, and data representative of the potentials generated on at least certain high-impedance electrodes in response to the application of the pulses, the data allowing a value to be determined for the electrochemical conductance of the skin. The method also regenerates a high-impedance electrode connected to the voltage source as a cathode.

Abstract: A system comprising implantable device, the implantable medical device including an intrinsic cardiac signal sensor, an impedance measurement circuit configured to apply a specified current to a transthoracic region of a subject and to sample a transthoracic voltage resulting from the specified current, and a processor coupled to the intrinsic cardiac signal sensor and the impedance measurement circuit. The processor is configured to initiate sampling of a transthoracic voltage signal in a specified time relation to a fiducial marker in a sensed intrinsic cardiac signal, wherein the sampling attenuates or removes variation with cardiac stroke volume from the transthoracic voltage signal, and determine lung respiration using the sampled transthoracic voltage signal.

Abstract: A method for multichannel multifrequency analysis of an object, applying a set of excitation signals to the object and sampling the response signal from the object, using uniform and non-uniform undersampling. Non-uniform sampling of the response signal is performed, i.e., the sampling is performed for two or more different frequencies in one observation time slot. Also, uniform sampling of the response signal is performed, i.e., the sampling of a signal, corresponding to one frequency, is performed for two or more channels within one observation time slot and then sampling the same signal for another frequency for two or more channels within the next observation time slot.

Abstract: A method, system and device for providing Point of Care Testing (POCT) are disclosed. The POCT comprises of a device that enables the patient to self conduct plurality of diagnostic tests for a chronic disease such as diabetes mellitus. The method is modular and enables the user to select set of tests from comprehensive list of diagnostic tests. The device provides a strip port to enable testing of various biochemical parameters. Also, the device comprises an ophthalmoscope with a built-in camera to capture images of the retina, a set of piezoelectric sensors for measuring pulse wave velocity (PWV), a pair of electrodes for measuring skin impedance. The method enables the device to log on the test data for future use and analysis. The device can be used for frequent monitoring of health parameters of a user suffering from diabetes mellitus.

Abstract: Methods for measuring cross-sectional areas in luminal organs. In at least one embodiment of a method for measuring a size parameter of a targeted treatment site of the present disclosure, the method comprises the steps of introducing an impedance device into a treatment site, the impedance device selected from the group consisting of an impedance catheter and an impedance wire; injecting a first solution of a first compound having a first conductivity into the treatment site; measuring a first conductance value at the treatment site using the impedance device, the first conductance value indicative of a bolus of the first solution, and calculating a size parameter of the treatment site based in part upon the first conductivity of the first solution, the first conductance.

Abstract: A system, method and apparatus for monitoring uterine and/or cervical activity indicative of labor in a patient. The system includes a medical device and a data processor in communication with the medical device. The medical device includes a structural component, a first electrode attached to the structural component, and a second electrode attached to the structural component. The structural component is structured to be in contact with a cervical surface and a vaginal surface of the patient, such that said first electrode is in electrical contact with said cervical surface and said second electrode is in electrical contact with said vaginal surface. The first electrode is adapted to receive an electrical activity of the cervical surface and the second electrode is adapted to receive an electrical activity of the uterus through the vaginal surface. The data processor is adapted to process the electrical activity of the electrodes to detect contractions on a surface of the patient indicative of labor.

Abstract: A system for monitoring a physiological parameter comprises a substrate, a pair of drive electrodes, a pair of detection electrodes, and an RFID apparatus. The substrate is arranged to be removably securable to a biological organism. At least the pair of drive electrodes or the pair of detection electrodes is secured to the substrate. The RFID apparatus is arranged to be in electrical communication with at least the pair of drive electrodes or the pair of detection electrodes. Methods of using the device are also provided.

Abstract: A portable bioelectric impedance monitor for monitoring extracellular fluid levels includes a tetrapolar electrode array lead with four electrodes arranged sequentially and axially along the lead, and circuitry coupled with the at least four electrodes configured to measure bioelectric impedance extracellular fluid in a human subject at a frequency of less than 15 kHz. The electrodes are adhered to a human subject/patient on the patient's torso or one of the patient's limbs. One embodiment includes a Tetrapolar Analog Front End Patient Interface circuit configured to convert two electrode operation of a commercial Impedance Converter, Network Analyzer into a tetrapolar operation for excitation and impedance measurement of the human subject.

Abstract: An apparatus for measuring electrodermal activity can include a first electrode in contact with a first portion and a second electrode in contact with a second portion of a stratum corneum, and in electronic communication with the second electrode through the stratum corneum. A processing module is electrically coupled to the first electrode and the second electrode and is operable to (a) bias the first electrode at a first voltage V+ and the second electrode at a second voltage V? (b) measure a current flowing between the first electrode and the second electrode, the current corresponding to the conductance of the stratum corneum, (c) subtract a compensation current from the measured current (d) measure a resulting current producing an amplified output voltage (e) measure a conductance of the stratum corneum, and (f) adjust at least one of the first voltage, the second voltage and the compensation current to desaturate the output voltage.

Abstract: A set of cardiogenic impedance signals are detected along different sensing vectors passing through the heart of the patient, particularly vectors passing through the ventricular myocardium. A measure of mechanical dyssynchrony is detected based on differences, if any, among the cardiogenic impedance signals detected along the different vectors. In particular, differences in peak magnitude delay times, peak velocity delay times, peak magnitudes, and waveform integrals of the cardiogenic impedance signals are quantified and compared to detect abnormally contracting segments, if any, within the heart of the patient. Warnings are generated upon detection of any significant increase in mechanical dyssynchrony. Diagnostic information is recorded for clinical review. Pacing therapies such as cardiac resynchronization therapy (CRT) can be activated or controlled in response to mechanical dyssynchrony to improve the hemodynamic output of the heart.

Abstract: A method of estimating stroke volume of the heart is described. In this method, the volume of the heart is estimated from electrical impedance data of the chest, at two different phases of the cardiac cycle. The stroke volume is estimated from the difference between the volumes estimated at the two phases.

Abstract: A system and method for determining physiological parameters based on electrical impedance measurements is provided. One method includes obtaining electrical measurement signals acquired from a plurality of transducers coupled to a surface of an object and constructing a system matrix to define one or more relationships between the impedance measurement signals. The method also includes decomposing the system matrix to separate the electrical measurement signals.

Abstract: An apparatus for the diagnosis of a biological sample is disclosed. An embodiments of the apparatus includes a probe, a probe head distally connectable to the probe, the probe head further comprising a plurality of electrode elements thereby forming an electrode array where each electrode element is variably actuatable to apply an electrical signal to the biological sample; an RF signal source for applying the electrical signal to the electrode array; an electrode selector adapted and configured to switch the electrical signal from the RF signal source between the plurality of electrode elements; and a detection circuit for analyzing a dielectric property received from the biological sample. Methods and kits for diagnosing a biological sample are also disclosed.

Abstract: In specific embodiments, one or more cardiogenic impedance signal template is stored, where each template has a corresponding morphology. Additionally, one or more cardiogenic impedance signal is obtained using electrodes implanted within a patient, where each signal has a corresponding morphology. The morphology of one or more obtained cardiogenic impedance signal is compared to the morphology of one or more stored template, to determine one or more metric indicative of similarity between the compared morphologies. The one or more metric indicative of similarity is used to analyze the patient's cardiac condition, to discriminate among arrhythmias and/or to adjust a cardiac pacing parameter.

Abstract: In a method and system for monitoring mechanical properties of a heart in a subject, multiple cardiogenic impedance values reflective of the impedance of the heart in connection with a transition from inhalation to exhalation in the subject are determined. Correspondingly, multiple cardiogenic impedance values reflective of the impedance of the heart in connection with a transition from exhalation to inhalation are determined. The impedance values are collectively processed to form a trend parameter. The value determination and processing is performed over several respiratory cycles spaced apart in time to form a plurality of trend parameters over time. The mechanical properties of the heart are monitored by processing these different trend parameters. The data collection and optionally at least a part of the data processing is performed by an implantable medical device.

Abstract: There is described a method for non-invasively measuring electrical activity in a joint of a subject, the method comprising: removably attaching in a non-invasive manner at least two electrodes to a skin surface around an articulation comprising the joint; generating electroarthrographic potentials within the joint by loading the articulation; capturing the electroarthrographic potentials using the at least two electrodes; discriminating between electroarthrographic potentials originating from joint tissue activity and those from other sources; and generating measurement signals representing the electrical activity of joint tissue.

Abstract: In a method of monitoring pulmonary edema in a human being, an electrical current is injected between a first electrode located in or around a heart and a housing of a medical device implanted in a chest region. A voltage potential is measured between a second electrode in a superior vena cava and a third electrode in the superior vena cava, where the voltage potential is created by the electrical current. Pulmonary edema is assessed based on an impedance value calculated from the electrical current and the voltage potential and a stored edema threshold impedance value.

Abstract: A biopotential measurement device (10) includes a measurement unit (14) and a display unit (16). The measurement unit (14) includes electrodes on a measurement surface. The electrodes detect the electric potential, at detection positions, of a living organism facing the measurement surface. The detection positions are determined within the measurement area. The display unit (16) is positionable on a surface opposite the measurement surface. The display unit (16) displays the electric potential detected at each detection position at positions within a display area. The positions within the display area correspond to the detection positions within the measurement area.

Abstract: A physiology signal sensing device includes an elastic pad and a strain sensor clement. The elastic pad is used for contact with a human body, and corresponds a blood vessel of the human body. The strain sensor element is disposed in the elastic pad and includes a conductive element. The conductive element deforms according to the vibration of the blood vessel, and the resistance value of the conductive element varies according to the strain of the conductive element.

Abstract: A method for detecting the state of hydration of a human or animal body includes carrying out impedance measurements on a body surface of the human or animal body. At least one bipole measurement and at least one quadrupole measurement are carried out and evaluated during the method.

Abstract: A medical apparatus and system for determining contact assessment includes a catheter having an elongate body having a proximal end, a distal end opposite the proximal end, and defining an injection lumen and an exhaust lumen, an expandable membrane defining a cooling chamber disposed at a point along the elongate body, the cooling chamber in fluid communication with the injection lumen and the exhaust lumen, and a contact assessment element which may be a temperature sensor located proximate the coolant return lumen for measuring an internal temperature of the chamber. The system may include the catheter, a console having a fluid supply, an exhaust path and at least one control mechanism operationally coupled to the temperature sensor for processing a temperature signal received from the temperature sensor. The apparatus and system can also have multiple electrodes to measure and process various impedances to determine contact assessment.

Abstract: Techniques for performing a lead integrity test during a suspected tachyarrhythmia are described. An implantable medical device (IMD) may perform the test prior to delivering a therapeutic shock to treat the suspected tachyarrhythmia and, in some cases, may withhold the shock based on the test. In some examples, the IMD measures an impedance of a lead a plurality of times during the suspected tachyarrhythmia. In some examples, the IMD measures the impedance a plurality of times between two sensed events of the suspected tachyarrhythmia. The IMD or another device may determine a variability of, or otherwise compare, the measured impedances to evaluate the integrity of the lead. Instead of or in addition to withholding a shock, the IMD or another device may change a sensing or stimulation vector of the IMD, or provide an alert to a user, if the integrity test indicates a possible lead integrity issue.

Abstract: A system and method are provided for determining characteristics of a device electrode disposed on a medical device within a body. A plurality of measurement electrodes are coupled to an external surface of the body and establish transmission paths for current through the body. An electronic control unit (ECU) is configured to cause transmission of current between a pair of active electrodes selected from the measurement electrodes and thereby generate a voltage on the device electrode. The ECU receives impedance signals from a plurality of passive electrodes among the measurement electrodes other than the active electrodes. The ECU establishes a virtual reference electrode at a reference position within the body responsive to the impedance signals and computes a position of the device responsive to the voltage on the device electrode and the reference position of the reference electrode. The ECU may also compute impedances at the device and measurement electrodes.

Abstract: Various embodiments relate generally to electrical and electronic hardware, computer software, wired and wireless network communications, and wearable computing and audio devices for monitoring health and wellness. More specifically, disclosed are an apparatus and a method for processing signals representing physiological characteristics sensed from tissue at or adjacent an ear of an organism. In one or more embodiments, a wearable device includes a sensor terminal and a physiological sensor coupled to the sensor terminal to sense one or more signals originating at the sensor terminal. The wearable device may also include a radio frequency (“RF”) communications interface. Also, the wearable device can include a processor configured to cause generation of data representing a physiological characteristic of the organism.

Abstract: A neural probe (10) is provided for in vivo communication with biological tissue, including stimulating neurons and/or recording neural electrical activity. The probe (10) may be constructed so that the immune response by the biological tissue in which the device is implanted is reduced over known implantable probes. The probe (10) can be constructed with a tip (16) that has a branched configuration, with electrodes (24) located along each of the branches (20). A biodegradable coating (18) is disposed over at least the tip (16) of the probe (10) to provide the probe (10) with sufficient integrity for insertion into the biological tissue and to degrade after insertion. The biodegradable coating (18) can have an anti-inflammatory drug or other bioagent distributed therein for localized release of the bioagent to further reduce the immune response.

Abstract: A bioelectrical impedance measurement apparatus is provided. A power signal and a frequency regulation signal for driving a measurement unit of the bioelectrical impedance measurement apparatus to perform bioelectrical impedance measurement are provided through a first sound channel output terminal and a second sound channel output terminal of a host device, and a bioelectrical impedance measurement result is received by a microphone input terminal of the host device.

Abstract: An EIT system 1 adapted to detect internal bleeding in a body portion, the EIT system 1 comprising a plurality of electrodes 3 adapted in use to extend in a substantially linear orientation across one side only of the body portion and to be applied in electrical contact with the skin of the body portion, a current source adapted to cyclically apply an electric current between one pair of the electrodes 3, a voltage measuring means to measure the voltage across each of the other pairs of the electrodes resulting from the current, a data collection system 2 and a data analysis system 4 to analyse data resulting from the voltages that are measured by the voltage measuring means, wherein the analysis system 4 is configured to obtain quantitative information related to amounts and rates of conductive tissue changes occurring in the body, based on an EIT analysis equivalent to that obtained from data derived from electrodes spaced around the full perimeter of the body portion.

Abstract: The invention comprises an apparatus for determining the contextual or physiological status of the individual wearing the apparatus. The apparatus is designed to be consumable or disposable. In most embodiments the invention comprises an adhesive housing. In some embodiments, two different sensors are secured to the housing. The apparatus is in electronic communication with a processing unit that can derive analytical status data by using the data received from the two sensors. In some embodiments, the processing unit is programmed to control other devices, or is programmed to trigger an event. In still other embodiments, the apparatus is in electronic communication with a separate computing device, which may contain the processing unit.

Abstract: A system and method for tracking a position of an interventional medical device configured to be deployed into a subject during a medical procedure. An anatomical dataset of the subject is acquired while at least one electrical sensor is disposed along the interventional medical device. A feedback signal is generated from the electrical sensor and is processed and analyzed to identify positional information of the interventional medical device. A position of the interventional medical device with respect to the anatomical dataset is identified and the position of the interventional medical device with respect to the anatomical dataset is shown on a display.

Abstract: A method and system is presented for an implantable wireless power receiver for use with a medical stimulation or monitoring device. The receiver receives transmitted energy through one or more non-inductive antenna(s), utilizes microelectronics to perform rectification of the received signal for generation of a DC power supply to power an implantable device, and may also utilize microelectronics to provide parameter settings to the device, or stimulating or other waveforms to a tissue.

Abstract: A method and apparatus for measuring an impedance of a tissue region inside a body of a patient. A first guidewire is advanced into a tissue region of a body of a patient, wherein the first guidewire comprises one or more electrodes electrically coupled to the tissue region. A second guidewire is advanced into the body, wherein the second guidewire comprises one or more electrodes electrically coupled to the tissue region of the body of the patient and spaced from the first guidewire. An error correction electrode is electrically coupled to the body. A voltage is applied across the first and the second guidewires. The impedance of the tissue region between the first and the second guidewires is measured while using an electrical pathway created by the error correction electrode.

Abstract: An implantable system includes terminals, a pulse generator, a sensing circuit, separate signal processing channels, and first, second and third multiplexers. The terminals are connected to electrodes via conductors of leads. Different subsets of the electrodes are used to define different electrical pulse delivery vectors, and different subsets of the electrodes are used to define different sensing vectors. The pulse generator produces electrical pulses, and the sensing circuit senses a signal indicative of an impedance associated with a selected sensing vector. The first multiplexer selectively connects outputs of the pulse generator to a selected one of the different electrical pulse delivery vectors at a time. The second multiplexer selectively connect inputs of the sensing circuit to a selected one of the different sensing vectors at a time. The third multiplexer selectively connects an output of the sensing circuit to one of the plurality of separate signal processing channels at a time.

Abstract: Impedance devices and methods to use the same to obtain luminal organ measurements. In at least one embodiment of an impedance device of the present disclosure, the impedance device comprises an elongated body having a distal body end, and a first electrode located along the elongated body at or near the distal body end, the first electrode configured to obtain one or more conductance values within a mammalian luminal organ within an electric field, wherein a measured parameter of the mammalian luminal organ can be calculated based in part upon the one or more conductance values obtained by the first electrode.

Abstract: A method for measuring the impedance of a portion of a subject, by passing a known current provided by a current source unit between a first pair of electrodes contacting the skin surface of the subject. The measuring of a voltage with a voltage measuring instrument, between at least one second pair of electrodes contacting the skin surface of the subject when the current source unit is passing the known current through the first pair of electrodes; calculating the bio-impedance of the portion of the subject based on the known current and the calibrated voltage.

Abstract: Apparatus for use in performing impedance measurements on a subject. The apparatus includes a processing system for causing a first signal to be applied to the subject, determining an indication of a second signal measured across the subject, using the indication of the second signal to determine any imbalance and if an imbalance exists, determining a modified first signal in accordance with the imbalance and causing the modified first signal to be applied to the subject to thereby allow at least one impedance measurement to be performed.

Abstract: An apparatus for determining tissue versus fluid components of an organ include a detector that generates a detector signal based on electrical signals derived from tissue and fluid. The apparatus includes a signal processor in communication with the detector which subtracts in real time a tissue component from the detector signal and produces a fluid volume signal. A method for monitoring a patient's fluid volume of a patient's organ. An apparatus for monitoring a patient's organ. A method for monitoring a patient's organ. A method to piggyback an admittance system onto a AICD/Bi-ventricular Pacemaker for a heart of a patient, in particular a weakened heart having features consistent with congestive heart failure. An apparatus for monitoring an organ, such as a heart, lungs, brain, skeletal muscle, and bladder of a patient which includes a detector which detects the admittance of the organ.

Abstract: The invention relates to carbon nanotube-containing composites as biosensors to detect the presence of target clinical markers, methods of their preparation and uses in the medical field. The invention is particularly suitable for the detection in patient biological specimens of bone markers and tissue markers. The biosensors of the invention include carbon nanotubes deposited on a substrate, gold nanoparticles deposited on the carbon nanotubes and, binder material and biomolecule deposited on the gold-coated carbon nanotubes. The biomolecule is selected to interact with the target clinical markers. The biosensor can be used as an in-situ or an ex-situ device to detect and measure the presence of the target clinical markers.

Abstract: An apparatus and method of testing electrical impedance of a multiplicity of regions of a photovoltaic surface includes providing a multi-tipped impedance sensor with a multiplicity of spaced apart impedance probes separated by an insulating material, wherein each impedance probe includes a first end adapted for contact with a photovoltaic surface and a second end in operable communication with an impedance measuring device. The multi-tipped impedance sensor is used to contact the photovoltaic surface and electrical impedance of the photovoltaic material is measured between individual first ends of the probes to characterize the quality of the photovoltaic surface.

Abstract: A method and apparatus for providing status of a parameter that includes detecting an alert level of a parameter monitored by an implanted medical device, transmitting data corresponding to the detected alert level from the implanted medical device to an external monitor, scheduling a follow-up interrogation session after receiving transmitted data corresponding to the detected alert level, and retrieving updated data from the implanted medical device corresponding to the monitored parameter during the follow-up interrogation session.

Abstract: The invention relates to estimation of a patient's propensity to suffer from symptomatic hypotension during extracorporeal blood treatment. An electromagnetic test signal, which is applied over a thoracic region of the patient via at least one transmitter electrode. A result signal produced in response to the test signal is received via at least one receiver electrode on the patient. A test parameter is derived based on the result signal. The test parameter expresses a fluid status of the thoracic region of the patient, and it is determined whether the test parameter fulfills an alarm criterion. If the test parameter fulfills an alarm criteria, an alarm signal is generated. This signal indicates that the patient is hypotension prone, and that appropriate measures should be taken.

Abstract: An impedance measurement circuit comprises a current source arrangement, a voltage measurement arrangement and a processor. The circuit is operable in a two-point measurement mode and a four-point measurement mode and the processor is adapted to derive the impedance to be measured by combining the measurement voltages from the two-point and the four-point measurement modes. This combines the results of both two-point and four-point measurement techniques to provide improved accuracy. In particular, the two results enable the effect of the electrode resistance to be cancelled.