Abstract: A system and method for determining smooth muscle motor activity in body organs. The system comprises electrodes for recording an analog signal in the subject's body, an analog to digital converter that converts the analog signal to a digital signal and a processor. Processing the digital signal includes obtaining power spectra of the digital signal, and identifying one or more frequency peaks in the power spectra. A peak in the power spectrum is identified within a frequency range in which an organ generates slow waves. The energy of the identified frequency peak is measured and an energy above a characteristic threshold is indicative of smooth muscle motor muscle motor activity in the respective organ.

Abstract: Tissue sensors house one or more sensor elements. Each element has a housing mounted substrate and a superstrate with a planar antenna between. A transitional periphery (TP) of a superstrate outer surface interconnects a base to a plateau. At least some of the TP has a generally smooth transition. Plural elements are spaced by the housing. Alternately, the superstrate TP is flat, the housing extends to the outer superstrate surface and a shield surrounds the element. The housing is flush with or recessed below the superstrate and defines a TP between the housing and superstrate. A method converts a reference signal to complex form; plots it in a complex plane as a reference point (RP); converts a measurement signal to complex form; plots it in the complex plane as a measurement point (MP); determine a complex distance between the MP and the RP; and compares complex distance to a threshold.

Abstract: A system and method for the efficient implementation of a complex exercise test is disclosed. A rule interpreter synthesizes interpretation statements based upon the processing of collected physiological data and user entered data with a series of exercise test interpretation rules. These statements aid a clinician in interpreting exercise test results by identifying detected abnormal or borderline conditions.

Abstract: An apparatus and technique for sensing biopotential signals wherein a conductive element is formed from a non-adhesive hydrogel material and configured to provide a conductive path between an electrode and a subject's skin for transmitting EEG signals from the subject to the electrode.

Abstract: A medical electrode for conducting signals, in particular for conducting signals from the human skin, is built up in at least two layers. A preferably metallic signal conductor can be connected to the signal-emitting subject, preferably in the form of a signal-conducting layer, and is arranged between an upper top layer and an adhesive layer which can be brought into contact with the signal-emitting subject. The electrode has a tapping pad, and an electrically insulating covering element arranged between the tapping pad and the signal-emitting subject, and at least one side of the preferably planar covering element is electrically conductive in construction.

Abstract: Biosensor, communicator, and/or controller apparatus, systems, and methods are provided for monitoring movement of a person's eye. The apparatus includes a device configured to be worn on a user's head, a light source for directing light towards one or both eyes of the user, one or more image guides on the device for viewing one or both eyes of the user, and one or more cameras carried on the device and coupled to the image guides for acquiring images of the eyes and/or the user's surroundings. The apparatus may include a cable and/or a transmitter for transmitting image data from the camera to a remote location, e.g., to processor and/or display for analyzing and/or displaying the image data. A system including the apparatus may be used to monitor one or more oculometric parameters, e.g., pupillary response, and/or to control a computer using the user's eyes instead of a mouse.

Abstract: Methods and systems for modifying or enhancing vision are described. In exemplary embodiments, neural or neuromuscular activity is analyzed to determine a focus or other quality of a visual input, and the focus or quality information used as a basis for controlling an adjustable lens system or optical system.

Abstract: The present invention provides a garment for measuring biological information, a biological information measurement system, a biological information measurement device and a method of controlling thereof capable of measuring biological information with accuracy regardless of variations of the constitution of each examinee. When an examinee wears a biological information measurement shirt 301, four limb electrodes 351 and 352 are arranged at positions so that the electrodes cover the body surface other than around the clavicle of the examinee. At that time, four limb electrodes 362 and 363 are assigned to positions so that they cover about the pelvis of the examinee.

Abstract: A system and apparatus for obtaining physiological data from a patient. The system and apparatus comprising at least one electrode disposed to collect physiological data from the patient and an electrode connection device having a conductive array formed by a plurality of conductive regions and a plurality of nonconductive regions. The conductive regions are suitable to be connected to the at least one electrode. The electrode may be connected to a first conductive region of the electrode communication device and wherein upon movement by the patient or the conductive array, the electrode is connected to a second conductive region of the conductive array.

Abstract: The present invention provides an non-adhering electrocardiographic and temperature signal detector comprising: (a) an electrocardiographic detecting working electrode, an electrocardiographic reference electrode and a temperature sensor connected together by a conduction chain; (b) a signal processing unit, for processing those signals obtained from said electrode or sensor, (c) a wireless transceiver for sending and receiving processed signal of electrocardiographic to the receiver at a far end unit or receiving data from the tar end unit; and (d) a power supply supplying power to the operation of the detector. The detector improves the uncomfortable of conventional adhering detector and increase the willing of a use due to the aesthetic, outlook of the detector and convenient to detect. Accordingly, the electrocardiographic and body temperature gas and opportunity to apply home care device.

Abstract: Accordingly, the present invention relates to a three-dimensional adhesive device to be attached to the body surface of a mammal comprising a microelectronic sensing system characterized by (a) a three-dimensional adhesive body made of a pressure sensitive adhesive having an upper surface and a bottom surface; (b) a microelectronic system embedded in the body of the pressure sensitive adhesive; (c) one or more cover layer(s) attached to the upper surface; and (d) optionally a release liner releasable attached to the bottom surface of the adhesive device. Suitably the microelectronic system is a microelectronic sensing system capable of sensing physical input such as pressure, vibration, sound, electrical activity (e.g. from muscle activity), tension, blood-flow, moisture, temperature, enzyme activity, bacteria, pH, blood sugar, conductivity, resistance, capacitance, inductance or other chemical, biochemical, biological, mechanical or electrical properties.

Abstract: The invention is a precordial pad for positioning EKG electrodes on a patient for anatomically correct and repeatable placement. Data can be transmitted from the EKG pad of the invention by wire or wireless means. The pad includes a sizing aid, and a positioning device. The invention is also a system for obtaining and sending EKG data.

Abstract: Methods and apparatus for non-invasively assessing physiological hard of soft tissue of human and other species are described. In a preferred embodiment, tissue is vibrationally stimulated in vivo through a frequency spectrum. The tissue reacts against the stimulus and the reaction is preferably measured and recorded. Based on analytical algorithms or comparisons with previously taken measurements, changes within the tissue can be detected and used for diagnostic purposes. Further embodiments describe the usage of the device and methods for in vivo intra-operative and post-operative implant evaluations and as a therapeutic tool.

Abstract: The invention relates to an apparatus for transcutaneous application of a stimulus or for transcutaneous measurement of a parameter on or from the skin surface of a vertebrate, in particular a human. The invention provides, in order to make the nerve stimulation in particular efficient, ergonomically favourable and easily manipulable for the patient, that the apparatus is designed so that it can be accommodated completely in the pinna (external ear) of the vertebrate.

Abstract: An ambulatory physiological monitor (10) is provided. The monitor includes at least one sensor for detecting at least one physiological parameter of a patient and a housing (42) adapted to be secured to the patient. A circuit (50) is located in the housing for receiving and processing a signal representative of the physiological parameter from the sensor to generate recordable physiological data and for determining if the data exceeds a preestablished alarm limit. An event indicator (12) is coupled to the housing for notifying the patient when the alarm limit has been exceeded. A wireless transmitter (28), operationally coupled to the circuit, is located in the housing for transmitting an emergency notification when the alarm limit has been exceeded. A patient-operable actuator (22) is coupled to the housing for preventing transmission of the emergency notification by the wireless transmitter upon activation by the patient within a predetermined time after the alarm limit has been exceeded.

Abstract: A small integrated diagnostic and identification system is disclosed that solves several problems associated with current sensory systems. The diagnostic and identification system comprises a bracelet with an identification mechanism that is difficult to remove and has a lock. Further, the diagnostic and identification bracelet comprises a microprocessor which communicates with various physiologic sensors wherein said physiological sensors are substantially within said bracelet. Alternatively some of the sensors may be mounted outside the bracelet and means are provided for communicating data from the outside mounted sensors to the bracelet. The physiologic sensors either routinely, automatically monitor an individual's physiology or monitor the physiology based on a user request. The resulting physiology data from each sensor is combined via a single output and displayed on a display device. The present invention may be integrated with a record management system to share and store an individual's records.

Abstract: A textile structure for detecting body surface electrical signals of human is provided. The textile structure includes a non-conductive textile, a conductive textile, and a plurality of test terminals. The non-conductive textile covers the human body. The conductive textile has a first region, a second region, and a third region. The first region is interdigitated into but not electrically coupled to the third region. The first to third test terminals are respectively coupled to the first to third regions of the conductive textile. The first and second test terminals are used for detecting ECG signals. The first and third test terminals are used for detecting respiratory signals.

Abstract: An ECG lead set including an ECG electrode assembly and a lead set hub. ECG electrode includes at least one electrode configured to receive biopotential signals from a patient, a plug connector for connecting said ECG electrode assembly, a web, connected between the at least one electrode and the plug connector and configured to form an electrical connection therebetween. The lead set hub includes at least one receptacle configured to receive the plug connector of the ECG electrode assembly.

Abstract: A body-surface mapping system is disclosed that uses a plurality of electrodes to map at least a portion of a human torso without having to adjust the positions of the electrodes. The body-surface mapping system energizes groupings or regions of electrodes, then compares and adjusts the current driven through each grouping or region of electrodes to produce near-uniform fields. The electrodes of the body-surface mapping system may be interconnected by wires capable of sensing interelectrode distances, such that the system can reconstruct a detailed model of a patient's torso surface. The body-surface mapping system may also use a catheter in addition to the body surface electrodes to compute both endocardial and epicardial voltage distributions.

Abstract: A sensor array apparatus for monitoring medical signals includes a flexible substrate adapted for positioning relative to the torso of a patient. The flexible substrate includes a central segment defining a central axis and is adapted to generally conform to an area extending along the sternum of a patient. The flexible substrate further includes an upper segment extending traversal across the central segment and adapted to generally conform to the chest area of a patient and a lower segment extending traversal across the central segment and adapted to generally conform to the abdominal area of the patient. The apparatus further includes a medical electrode disposed on at least one of the segments and a connector in electrical communication with the medical electrode and adapted to connect to an electronic monitoring system.

Abstract: A method and system for acquiring a phalange edge image using an X-ray image of a hand are provided. The method includes: selecting a region of interest from an X-ray image of the hand; acquiring a soft tissue background gray level removed image by removing a soft tissue background gray level from the region of interest; and extracting a phalange edge image from the soft tissue background gray level removed image.

Abstract: A self-adhering sensor for non-invasively attaching to a portion of a skin is provided. The sensor comprises a biocompatible substrate, and an array of solid nanoelectrodes coupled to the biocompatible substrate and configured to self-adhere to the skin. Also provided is a sensor for attaching to a portion of a skin, where the sensor comprises an array of solid electrodes configured to self-adhere to the skin, where each of the solid structures comprises a stem and one or more projections extending out from the stem, where both the stem and the projections are solid. The stem comprises a mechanical stopper to control the extent of penetration of the solid electrodes into the skin. The sensor further comprises an electrolyte coating disposed on one or more of the solid structures.

Abstract: High reliability electrical connections between a helical strand and flat electrodes, such as strip electrodes found in implantable neurostimulator systems, are described. The connection consists of a crimp joint in which an inside diameter mandrel is used to provided the coil with sufficient radial rigidity to ensure structural integrity of the crimp. The mandrel is made of a relatively soft biocompatible material that deforms rather than damages the fine wires of the helical strand during crimping. The crimp is accomplished by radial deformation of an annular or semi-annular crimping member that receives the helical strand/mandrel assembly.

Abstract: A two-component monitoring device and system for monitoring blood pressure from a patient is disclosed herein. The two-component monitoring device includes a disposable component and a main component. The disposable component features: i) a backing structure having a first aperture; and ii) first and second electrodes, each electrode connected to the backing structure and including an electrical lead and a conductive electrode material, and configured to generate an electrical signal that passes through the electrical lead when the conductive electrode material contacts the patient. The main component includes: i) first and second connectors configured to connect to the first and second electrical leads to receive the first and second electrical signals; and ii) an optical component comprising a light source that generates optical radiation and a photodetector that detects the optical radiation. The optical component inserts into the first aperture of the disposable component.

Abstract: A contact lens with a conductive outer shell (one electrode of a two-electrode electrophoresis device) and a preferably soft, preferably disposable contact lens for contacting a patient's eye, assists in delivering dilation drops or other medicaments to a patient's eye. Advantageously, the lens is used with a relatively small hand-held power source. Electrophoresis can be used to help deliver dilation drops more rapidly, regardless of the delivery apparatus used for the electrophoresis.

Abstract: Methods and apparatuses for deploying percutaneous probes. An apparatus in accordance with one embodiment of the invention includes a housing and a percutaneous probe having a sharp end and positioned within the housing. The percutaneous probe is movable relative to the housing between a stowed position and at least one of a first deployed position and a second deployed position. The percutaneous probe can project from the housing by a first distance when in the first deployed position and a second distance greater than the first distance when in the second deployed position. A depth control device can operatively couple to the percutaneous probe and can have a first configuration to allow the percutaneous probe to be moved to the first deployed position and a second configuration to allow the percutaneous probe to be moved to the second deployed position.

Abstract: A monitoring system (800) is operative for receiving sensor signals and analyzing the sensor signals to identify events or conditions of interest, such as colic, with respect to a monitored animal. The sensors may be animal-borne sensors such as motion related sensors. The system (800) includes a processor (802) operative to identify the conditions of interest based on a stored pattern database (806), threshold tables (808) and heuristic engines (812). Upon identification of a condition of interest, a human expert may be consulted and alerts may be generated as required.

Abstract: A heartbeat detection device includes a pair of electrode units, a transmitting unit and a receiving unit. The transmitting unit is electrically connected to the paired electrode units each by respective wires. The paired electrode units each include an electrode body and a hook sandwiching a bottom part of a garment for example on a body for holding the electrode units on respective predetermined parts of the body. The hook is formed on the front side of the electrode unit. The transmitting unit includes a transmitting-unit body and a hook sandwiching an upper part of the garment for holding the transmitting unit on the garment. The hook is formed on the rear side of the transmitting unit. The lightweight heartbeat detection device is thus achieved that can ensure electrical contact between the electrode units and respective predetermined parts of the chest without causing a feeling of tightness.

Abstract: The invention relates to a sensor (42) placed on the skin, which can advantageously be integrated in a garment and has a contact layer in contact with the skin containing conductive fibres for receiving signals and a moisture retentive moisture layer (41) on top of the contact layer.

Abstract: A portable lead alignment device is provided for aligning, organizing and storing in a pre-assembled fashion the leads extending from an EKG apparatus. The device includes an elongate flexible support with at least one linear array of chest lead alignment tunnels disposed thereon. Each tunnel snugly accommodates a chest lead so that the lead can be slid longitudinally relative to the support. However, the tunnels prevent the leads from being separated from the device. The lead alignment device may further include a plurality of ground lead organizers for releasably retaining the ground leads in a neat looped arrangement on the support.

Abstract: A precordial overlay and dual backing assembly is expeditiously affixed together in a manner which allows it to be packaged in an unalterable form. When needed to obtain an ECG reading, the assembly is removed from the packaging and the precordial overlay swiftly separated from the dual backing. The dual backing is discarded. The precordial overlay is quickly and accurately positioned on a patient, The precordial overlay of the assembly comprises an elongated band having a first and a second generally rectangular-shaped sections joined together by an intermediate section. All three sections have at least one cut-out to receive an adhesive-backed electrode assembly. The dual backing of the assembly is similarly shaped and comprises a thin intermediate substrate with release agents on each side and a thin lower substrate with a release agent on a top side. The intermediate substrate further has a set of bent-back flaps, each flap positioned to receive an underside of one of the electrode assemblies.

Abstract: A surgical exploratory testing system (8, 11) to select a laparoscopic trocar's puncture site (5, 6, 7) through the abdominal wall (1) is characterized in that said system is designed as a coil unit (9) which can be placed on the puncture site (5, 6, 7) and which is connected to an eddy current detector (11).

Abstract: The invention is a precordial pad for positioning EKG electrodes on a patient for anatomically correct and repeatable placement. Data can be transmitted from the EKG pad of the invention by wire or wireless means. The pad includes a sizing aid, and a positioning device. The invention is also a system for obtaining and sending EKG data.

Abstract: A patient monitoring system is disclosed. The patient monitoring system includes at least one monitoring cable, a plurality of connecting wires, and a plurality of connectors. The plurality of connecting wires are housed within an outer covering and each extend from a first end to a second end of the at least one monitoring cable. The plurality of connectors are arranged in an in-line sequence from the first end to the second end of the at least one monitoring cable and may include at least one ECG connector and at least one non-ECG connector. The patient monitoring system may also be configured to provide strain relief for the at least one cable.

Abstract: A method and system for wireless ECG monitoring is provided. An electrode connector, transmitter and receiver operate with existing electrodes and ECG monitors. The electrode connector includes connectors for attaching to disposable or reusable single electrodes. The transmitter transmits the signals from the electrodes to the receiver. The receiver passes the electrode signals to the ECG monitor for processing. ECG monitors used with an electrical conductor, for example wire connections to electrodes, are connected with the receiver, avoiding the purchase of a new monitor. Any legacy ECG monitor, including different ECG monitors, connects with the receiver using the ECG monitor's lead-wires. The ECG monitor operates as if directly connected to the electrodes without the problems discussed above associated with wires running from the ECG monitor to the patient.

Abstract: A system for unobtrusively measuring bioelectric signals developed by an individual includes multiple sensors, one or more of which constitutes a capacitive sensor, embedded into or otherwise integrated into an object, such as a chair, bed or the like, used to support the individual. The object serves as mounting structure that holds the sensors in place. The sensors are preferably arranged in the form of an array, with particular ones of the sensors being selectable from the array for measuring the bioelectric signals which are transmitted, such as through a wireless link, for display and/or analysis purposes.

Abstract: A method and device for automatically assessing loss of hearing sensitivity and compression (recruitment) with user defined frequency resolution by means of extrapolated DPOAE I/O functions and ABRs as well as for automatically fitting hearing aids without any cooperation of the subject tested using a device having a display screen attached to a handheld device generating and collecting otoacoustic emission signals and brain stem response signals into a programmed with a clinical audiogram with fitting parameters for hearing aids calculated on the basis of assessed hearing threshold and compression and identifying the type of hearing required for the individual.

Abstract: A method and apparatus for acquiring and processing electrical signals produced by a patient's heart. The apparatus includes fewer than ten electrodes for attachment to the patient. Each electrode is attached in a respective one of the standard ten-electrode, twelve-lead ECG positions. The device includes a signal processor connected to the electrodes for acquiring electrical signals from the electrodes and generating a twelve-lead ECG from the electrical signals. The signal processor generates less than twelve of the leads mathematically. For the method of the invention, a plurality of less than ten electrodes are attached to the patient. Each electrode is attached in a respective one of the standard ten-electrode, twelve-lead ECG positions. Electrical signals are acquired from the electrodes and a twelve-lead ECG is generated from the acquired electrical signals. Not all twelve leads are generated mathematically.

Abstract: An electrode 4 for detecting a biological signal and a loop antenna 3 are integrally mounted on a support 2 placed on the surface of a living body and a transmitter 5 is placed on the support 2. A biological signal detected on the electrode 4 is input through a connector 11 to electric circuitry 10 of the transmitter 5 and an electric signal processed by the electric circuitry 10 is output through connectors 12 and 13 to both ends of the loop antenna 3 from which the biological signal is emitted to a receiver. At this time, the opening face of the loop antenna 3 is in a direction almost perpendicular to the surface of a living body for improving sensitivity.

Abstract: A vest for providing electrical stimulation is disclosed. The vest includes front and rear sections and a controller. Left front and right front electrodes are provided on interior surfaces of the front section, and left rear and right rear electrodes are provided on interior surfaces of the rear section. The controller is provided on an exterior surface of the front section and provides selectively adjustable electrical pulse signals to the electrodes via wires routed over the exterior surface of the front and rear sections to the electrodes through respective openings provided in the front and rear sections. The electrodes and the front and rear sections include means for positional adjustment of the electrodes on the interior surfaces of the front and rear sections. The vest can be used for electrical stimulation of muscles or nerves of the abdomen and back for users having varying body types and sizes.

Abstract: A portable apparatus which allows a user to perform self-diagnostic evaluation of nerve sensory latency between a pair of epidermal locations proximal to nerve conduction paths. The device provides a simple and low-cost self-diagnostic apparatus which may be used for the detection and ongoing monitoring of sensory latency, such as sensory latency which is the result of carpal tunnel syndrome. The apparatus is powered by a single battery which provides power to all circuitry of the apparatus. Upon power activation, the device generates a series of high voltage stimulus pulses at an electrode in epidermal contact with the user/operator. The nerve response voltage is detected by a second electrode located along nerve pathway and the time delay between stimulus and response is displayed and periodically updated as each new response is detected.

Abstract: A method and arrangement for acquiring an electroencephalogram (EEG) are disclosed. A first set of electrodes is arranged to sense cortical signals generated primarily in a region of interest (ROI). A second set of electrodes are arranged to sense cortical signals generated inside and outside of the ROI. Individual signals sensed by each electrode of the first and second sets of electrodes are directed to a signal analyzer.

Abstract: A universal and reversible disposable ECG sensor positioning mask and method for use with electrocardiogram diagnostic equipment for left and right chest ECGs in which the mask has at least nine sensors, six of which can be used at any one time to provide up to four different sizes to accommodate varying sized human torsos.

Abstract: A system for detecting and analyzing electrical activity in the anatomy of an organism underlying an electrode array provides signals corresponding to electrical activity adjacent each electrode. Such signals are correlated to the underlying anatomy of the organism and representative outputs presented through various types of output devices. Such outputs may include variations in coloration or other qualities in correspondence with representations of underlying anatomical structures. The system includes novel electrode structures (200, 224, and 284) and methods for producing and attaching electrode arrays (240 and 280) to the organism. The exemplary form of the invention is used in connection with the diagnosis of muscle activity in the lower lumbar regions of humans. Levels of muscle activity detected are analyzed by correlation with the muscular structures underlying the electrode array. Forms of the invention may be used in other applications.

Abstract: A system for detecting and analyzing electrical activity in the anatomy of an organism underlying an electrode array provides signals corresponding to electrical activity adjacent each electrode. Such signals are correlated to the underlying anatomy of the organism and representative outputs presented through various types of output devices. Such outputs may include variations in coloration or other qualities in correspondence with representations of underlying anatomical structures. The system includes novel electrode structures (200, 224, and 284) and methods for producing and attaching electrode arrays (240 and 280) to the organism. The exemplary form of the invention is used in connection with the diagnosis of muscle activity in the lower lumbar regions of humans. Levels of muscle activity detected are analyzed by correlation with the muscular structures underlying the electrode array. Forms of the invention may be used in other applications.

Abstract: A medical electrode designed to prevent the passage of harmful electric current to a patient, thereby preventing tissue damage and electrocution. In the preferred embodiment, the inventive medical electrode is comprised of a proximal end, a distal end, a conductive lead connecting the proximal and distal ends, and a fuse located upon the medical electrode for preventing the passage of harmful electric current to a patient. For additional protection from induction current, the preferred location of the fuse is aft of the conductive lead element of the electrode. While a fuse is used in the preferred embodiment, the fuse could be replaced with a diode or a circuit breaker.

Abstract: A system for detecting and analyzing electrical activity in the anatomy of an organism underlying an electrode array provides signals corresponding to electrical activity adjacent each electrode. Such signals are correlated to the underlying anatomy of the organism and representative outputs presented through various types of output devices. Such outputs may include variations in coloration or other qualities in correspondence with representations of underlying anatomical structures. The system includes novel electrode structures (200, 224, and 284) and methods for producing and attaching electrode arrays (240 and 280) to the organism. The exemplary form of the invention is used in connection with the diagnosis of muscle activity in the lower lumbar regions of humans. Levels of muscle activity detected are analyzed by correlation with the muscular structures underlying the electrode array. Forms of the invention may be used in other applications.

Abstract: An ECG electrode chest pad particularly adapted for use in emergency room situations having upper fit portions with upper limb electrodes, and elongated central or medial base fit portion with a plurality of precordal unipolar electrodes and lower fit portions with lower limb electrodes, said electrodes being attached to leads which are internal to the base chest pad and terminate into at least one lead branch adapted to plug into an ECG monitor and having a perforation in the base pad material such that one group of electrodes may be separated from a second group of electrodes to facilitate ease of patient monitoring and complimentary medical procedures.

Abstract: A medical extravasation device has an electrode patch that can attach to the skin for sensing electrical information. Tissue impedance is calculated from the electrode patch signals. The patch has elongate pick-up electrodes inboard of elongate energizing electrodes. The measuring zone determined by the elongate space between the pick-up electrodes enhances sensitivity and specificity. The presence of an extravasation is determined by interpreting the tissue impedance measurement. The method for determining the extravasation includes a first step of determining a pre-injection baseline measurement of the tissue impedance. Then, the tissue impedance is monitored during the procedure itself. A predetermined amount of change in tissue impedance is determined to indicate an extravasation.

Abstract: The technique for detecting extravasation during the injection of fluid into a patient involves the establishment of a baseline representing impedance at the zone of the injection prior to the injection starting. Extravasation is signaled when at least two characteristics appear. First is that the impedance varies from the baseline more than a predetermined amount in more than a predetermined number of discreet time slots called epochs herein. Second is that, the rate of change of the impedance, which is called the slope herein, is consistently greater than a predetermined amount.