Abstract: The present invention relates to a computer program and to a method for controlling the computer program, wherein a control signal is sent to the computer program when an optical marker, in particular a two-dimensional barcode (2a, 2b, 2c), is detected by an intraoral scanner (1), which signal switches the computer program to a predefined state. A device for controlling the computer program comprises a support (3) on which at least one optical marker is arranged. The optical marker has an inscription (21a, 21b, 21c) which indicates a state of the computer program to which the computer program can be switched by detection of the optical marker by the intraoral scanner (1).

Abstract: The specification describes a manifold for use in a tip section of a multi-viewing elements endoscope. The manifold has: a first section attached to an elongated second section, where the proximal section has a proximal socket and the distal section has a distal socket; a groove having a first portion along a first axis parallel to a longitudinal axis of the manifold, and a second portion along a second axis tilted at an angle to the first axis; and a working channel tube wherein a distal segment of the tube extends along the first axis to lie within the first portion of the groove, and where a proximal segment of the tube extends along the second axis to lie within the second portion of the groove.

Abstract: The invention relates to an endoscope (1), comprising an endoscope tube (3) fastened to a main body (2). According to the invention a connection piece (4), to which a cannula end (6) of a cannula (7) that can be placed onto the endoscope tube (3) can be fastened, is arranged on the endoscope tube (3) in such a way that the connection piece is axially movable between a first position and a second position, wherein a shaped element (8) of the main body (2) and a counter-shaped element (9) of the connection piece (4) form a rotation-prevention mechanism in the first position and enable a rotational motion of the connection piece (4) about a longitudinal axis of the endoscope tube (3) in the second position.

Abstract: A distal end cover of an endoscope includes a peripheral edge portion configured to form an opening that externally exposes a space in which a raising base is housed, in a distal end member; a planned-to-be-torn-apart section including a tear starting point disposed on the peripheral edge portion, and a thin portion that is connected to a to-be-torn-apart section of the peripheral edge portion torn from the tear starting point, on an inside surface of a surface facing the opening or an inside surface of at least one side surface that connects the peripheral edge portion and the surface facing the opening; and an engagement portion configured to be engaged with an outside surface of the distal end member by engaging in a direction intersecting the outside surface.

Abstract: An endoscopic vacuum controller may include a housing having a vacuum inlet, a vacuum outlet configured to be coupled to a vacuum source, and a vacuum passage fluidly coupling the vacuum inlet to the vacuum outlet. The vacuum controller may also include an actuator supported by the housing and configured to control the flow of fluid through the vacuum passage. An indicator may be supported by the housing to provide an indication that a predetermined vacuum level is being drawn at the vacuum inlet. The vacuum controller may include a connector to detachably couple the housing to an endoscope shaft. The connector may be configured to slidably couple the housing to the endoscope shaft to allow adjustment of the controller along the length of the shaft while the housing remains coupled to the shaft.

Abstract: A fluid plug unit includes a cylinder connected to a first conduit and a second conduit, and a piston configured execute switching between a first position where leakage of a fluid in the first conduit to an outside is suppressed, and a second position where the fluid is sucked. The fluid plug unit includes a first passage configured to communicate with the first conduit and the second conduit when the piston is disposed in the first position, and to shut off communication with the first conduit when the piston is disposed in the second position, and a second passage configured to shut off communication with the first conduit when the piston is disposed in the first position, and to communicate with the first conduit and the second conduit when the piston is disposed in the second position.

Abstract: An image pickup unit includes: a focus switching type observation optical system including fixed lenses and a moving lens; fixed frames that hold the fixed lenses; a moving frame that is arranged to be movable back and forth in a direction along a photographing optical axis of the observation optical system and holds the moving lens; and a correction frame fixed in the fixed frames, configured to house the moving frame such that the moving frame can advance and retract, including a stopper that abuts the moving frame to restrict movement in one direction of the photographing optical axis, and being slightly adjustable to realize one of focal lengths of the observation optical system.

Abstract: Devices and methods for locating sinus ostia and positioning a guide wire within the sinus ostia. The subject devices comprise a shaft having a distal end, a proximal end, a curved region located between the distal and proximal ends, and an interior channel, an extensible and retractable guide wire movably mounted within the interior channel and a probe tip joined to the guide wire. Certain devices further include expandable portions for engaging and treating body anatomy.

Abstract: The present invention provides an intraoral imaging and illumination apparatus comprising a rear portion and a front portion removably connected to the rear portion. The front portion is formed as a light guide. The rear portion comprises an imaging device and an illumination device. The illumination device is adapted to couple light into the front portion and towards a leading end of the front portion opposite the rear portion so as to illuminate a first object. The imaging device is adapted to image the first object.

Abstract: A device which illuminates internal tissue and organs of a patient is described. The illumination member includes an array of light-emitting diodes (“LEDs”). The arrangement of the array depends on the configuration of the device and the procedure for which the device is being used. In all cases, the illumination member is used to illuminate relevant organs or structures in the body in order to increase visibility during surgical procedures. The LED array reduces the potential for inadvertent injury to internal structures for procedures located throughout the body. These procedures include those involving the reproductive organs of males and females, gastric and bariatrics, and other structures in the abdomen.

Abstract: To facilitate observation of object(s), an imaging process can include or an imaging device can perform detecting a position of a focusing point of an eye of a user, determining, according to the position of the focusing point, an object gazed by the user, and changing a size of target imaging of the gazed object on the fundus of the user according to a predetermined zooming rule. The size of the target imaging of the gazed object on the fundus of the user can be automatically changed by optical zooming processing, so that the user can observe the gazed object at a modest distance and with a moderate size of the imaging on the fundus, and therefore it may be convenient for the user to observe the gazed object.

Abstract: A method for providing a reference level for an eye-opening width, the eye-opening width representing an instantaneously detected distance between the eyelids of an eye, the method having an ascertainment step, in which the reference level is ascertained using values of the eye-opening width, where the eye-opening width is greater than a limiting value.

Abstract: The invention relates to a trial frame for determining the subjective refraction of a subject, comprising two lens holder devices for receiving lenses, a bridge, which adjustably connects the lens holder devices, a nose rest device having a pivotable and height-adjustable nose rest and two temples, which are adjustable in length and height, the bridge and the lens holder devices together forming a guide means for guiding the lens holder devices in the longitudinal direction of the bridge, the bridge having a spindle gear comprising a threaded spindle for adjusting the distance of the lens holder devices, wherein at least one guide protrusion is formed on each of the lens holder devices, said guide protrusion engaging into a guide groove formed in the bridge, open threaded sections being formed on each of the lens holder devices, the threaded spindle being engaged with the threaded section.

Abstract: Optical coherence tomography (OCT) imaging systems are provided including a source of broadband optical radiation coupled to a sample arm of the OCT imaging system; a beam shaping optical assembly in the sample arm, the beam shaping optical assembly being configured to receive optical radiation from the source as a beam of optical radiation and to shape the spatial profile of the beam of optical radiation; a scan mirror assembly coupled to the beam shaping optical assembly; and objective lens assembly coupled to the beam shaping optical assembly. The beam shaping optical assembly includes a lens assembly configured to change a NA of the OCT system without changing a focus; to change a focus of the OCT system without changing a NA of the system; or to change both the NA and the focus of the OCT system responsive to a control input.

Abstract: Provided is an imaging apparatus capable of imaging a confocal image and a nonconfocal image, in which an image intended by an examiner is provided easily and rapidly. The imaging apparatus includes: an acquiring unit configured to acquire a confocal image and a nonconfocal image of an eye to be inspected; a display unit configured to display at least one of the acquired confocal image and the acquired nonconfocal image; an analysis unit configured to analyze the acquired confocal image and the acquired nonconfocal image; and a display control unit configured to change a display form displayed on the display unit in accordance with an analysis result obtained by the analysis unit.

Abstract: A system for monitoring cardiac health of a user including a local sensing subsystem, a contactless interrogation subsystem, and a remote monitoring subsystem. The local sensing subsystem may include a sensor patch configured to attach to the user and include a substrate, a passive radio-frequency identification transponder, and a first antenna. The contactless interrogation subsystem may include an interrogator separated from the sensor patch, which may include a second antenna, a demodulator, and a communications link. The remote monitoring subsystem may include a computing system comprising a processor for executing instructions. The local sensing subsystem may be adapted to perform at least one scan. The contactless interrogation subsystem may be adapted to operate the demodulator to receive a cardiac event and to operate the communications link to transmit the cardiac event. The remote monitoring subsystem may be adapted to execute the instructions to detect an arrhythmia from the cardiac reading.

Abstract: An ultrasonic communication system and method provide a networking framework for wearable devices based on ultrasonic communications. The ultrasonic communication system and method incorporate a set of physical, data link, network and application layer functionalities that can flexibly adapt to application and system requirements to efficiently distribute information between ultrasonic wearable devices.

Abstract: A patient monitoring system includes a patient data acquisition system (12) to acquire patient data via patient physiological sensors (28). A first patient monitor display (16) and first audio system (18) is disposed inside a patient room. A second patient monitor display (20) and audio system (22) is disposed outside the patient room. A control system (14) outputs acquired patient data via at least one of the first patient monitor display and the second patient monitor display and outputs a patient audio monitor signal (60) generated based at least in part on acquired patient data using at least one of the first and second audio systems (18, 22). The control system (14) provides a first audio configuration (42) for operating the first audio system (18) and a second audio configuration (44) for operating the second audio system (22).

Abstract: An optical biological measuring device includes a light transmission/reception element 30 having a plurality of light transmission probes 12, light reception probes 13 and reference probes 14; a second observation signal acquiring element 25 for acquiring a second observation signal indicating a time-course variation relating to a cerebral activity; a first observation signal acquiring element 24 for acquiring a first observation signal indicating a time-course variation relating to the blood flow in the skin; and an analysis control element 40 for generating a removal target component removal observation signal based on the first and second observation signals.

Abstract: Apparatuses and methods for producing improved photographs suitable for measuring teeth whiteness with a handheld camera using a camera jig are provided. The camera jig includes a base that contacts a surface. The camera jig also includes a light shield made from a tubular structure defining an interior cavity. The camera jig further includes a slot in the tubular structure that supports the handheld camera at a predetermined distance from a target, which may be teeth of a user. The slot aligns a lens of the handheld camera with the target. Further, the light shield blocks substantially all ambient light, other than light of a light source of the handheld camera, from the target as it is photographed.

Abstract: Bubbles (118-122) are utilized in some embodiments as part of a photoacoustic contrast agent (162) and, in some embodiments, to localize one or more locations (126-38) of a source of acoustic energy. The bubbles, such as microbubbles, can be used in proximity of nanoparticles of a first photoacoustic contrast agent, thereby affording a second photoacoustic contrast agent. The bubbles can intercept and re-radiate acoustic energy emitted by light-based activation of the first photoacoustic contrast agent in the immediate vicinity of the bubbles. As a further option, if the nanoparticles permeate further to tissue structures but remain in close enough proximity, their positions can be triangulated by the nearby bubbles, based on direction (144-148) and time delays (150-160) of ultrasound received by a transducer array.

Abstract: A photoacoustic apparatus comprises a light source; an irradiation unit configured to radiate light from the light source to an object that contains a contrast agent; a receiving unit configured to receive acoustic waves generated when the contrast agent absorbs the light radiated by the irradiation unit and output an electrical signal; a correction processing unit configured to correct a signal strength of the electrical signal, based on a temporal change in a concentration of the contrast agent contained in the object; and an acquiring unit configured to acquire characteristics information on the object, based on the electrical signal that has been corrected by the correction processing unit.

Abstract: An imaging system for an object such as human or animal tissue applies acoustic vibrations localized in two or three dimensions and simultaneously illuminates the object with an illuminating electromagnetic wave. A transmitter or receiver is provided that has an antenna with at least one coil that surrounds an axis along which at least a portion of the acoustic vibration is output.

Abstract: A temperature measurement probe (130) for use in a magnetic resonance environment, includes an elongated substrate (202), at least one highly resistive, electrically conductive traces (200, 200a, 200b, 200a?, 200b?) one printed at least one thermistor (204) disposed on the substrate and electrically connected with the trace. The thermistor is configured to be placed in thermal communication with a patient in the magnetic resonance environment. In some embodiments, the printed trace may be carbon-based, silicone based, or may be a doped semiconductor material.

Abstract: A noninvasive arterial condition detecting system includes a processing device and an electronic stethoscope configured for auscultating carotid artery to receive sound signals. The processing device is connected to the electronic stethoscope. The processing device records the sound signals, preprocesses the sound signal to reduce noise, measures a trough-peak distance and a trough-peak time, and generates an estimate result of arterial conditions according to the trough-peak distance and the trough-peak time. The trough-peak distance and the trough-peak time are related to the health of the carotid artery walls.

Abstract: An integrated passive wireless chip diagnostic sensor system is described that can be interrogated remotely with a wireless device such as a modified cell phone incorporating multi-protocol RFID reader capabilities (such as the emerging Gen-2 standard) or Bluetooth, providing universal easy to use, low cost and immediate quantitative analyzes, geolocation and sensor networking capabilities to users of the technology. The present invention can be integrated into various diagnostic platforms and is applicable for use with low power sensors such as thin films, MEMS, electrochemical, thermal, resistive, nano or microfluidic sensor technologies.

Abstract: This invention is directed to devices and methods for assessing a patient. The devices have at least one impedance measuring element functionally connected to a programmable element, programmed to analyze an impedance measurement, and to provide an assessment of at least one respiratory parameter of the patient. Preferably the device includes electronics which aid in calibration, signal acquisition, conditioning, and filtering.

Abstract: A system for maintaining permissive hypotension in a patient includes monitoring of blood perfusion and pressure, combining blood perfusion and pressure data to determine systolic blood pressure, monitoring for detection of systolic blood pressure below a critical threshold value, and providing an alert to perfusion options to maintain permissive hypotension. The system may be adapted to adjust the critical threshold value for systolic blood pressure as treatment progresses.

Abstract: A method for configuring a monitoring component for a user includes receiving an electrocardiograph (ECG) signal from an ECG component, receiving a weight signal from a scale component, and combining features extracted from the ECG signal and the weight signal to generate a current biometric signal. Responsive to the current biometric signal matching a historical biometric signal, the method includes obtaining a user profile and determining a health status for association with the user profile by classifying the current biometric signal using disease models and fitness models.

Abstract: Automatic method, as well as the related system and the tools allowing the same to be executed, for measuring and processing blood pressure starting from a detected pressure signal, the method operating in the time domain for discriminating whether the detected signal is an adequate measurement or not and, where it is not, time domain analysis automatically selects a low-pass filter to, possibly iteratively, apply to the detected pressure signal for having correct values and wave form of the blood pressure.

Abstract: A system for facilitating measurement of a person's blood pressure. The system has a cuff that is configured to: a) be operatively situated in relationship to a person's arm; and b) strategically exert pressure on the person's arm to controllably restrict blood flow therein. An arm positioning assembly is configured to be operatively engaged by a hand on the person's arm to consistently place the person's arm in relationship to the cuff with the cuff operatively situated in relationship to the person's arm as a blood pressure measurement is taken.

Abstract: In a system and method for identifying a driver of a source associated with a heart rhythm disorder, data are accessed from a plurality of sensors representing biological activity in the heart. A first region and a second region of the heart, which comprise the source of the heart rhythm disorder, are identified. If the first region of the heart has repeating centrifugal activation and controls the second region of the heart for at least a predetermined number of beats, the first region is identified as controlling the source of the heart rhythm disorder.

Abstract: Examples of monolithic integrated emitter-detector array in a flexible substrate for biometric sensing and associated devices and methods are disclosed. One disclosed example device includes a flexible substrate; a first array of emitters embedded in the flexible substrate, the first array of emitters configured to emit first electromagnetic (EM) signals; a first array of detectors embedded in the flexible substrate, the first array of detectors configured to detect reflections of the first EM signals; a first scanning circuit coupled to the first array of emitters, the first scanning circuit configured to selectively activate individual emitters of the first array of emitters; and a first sensing circuit coupled to individual detectors of the first array of detectors, the first sensing circuit configured to receive a detection signal from at least one of the detectors of the first array of detectors.

Abstract: A method of photoplethysmography includes processing a signal based on at least one signal from at least one sensor arranged to capture light from a living subject to extract information on a characteristic of a periodic biological phenomenon. At least one of the signals from at least one sensor is obtained via sensing radiation as to a peak in an absorption spectrum of water.

Abstract: A living-body information measuring device includes plural light-emitting elements, a light-receiving element that is disposed at a position at different distances from the light-emitting elements and that receives reflected light beams that are reflected from a living body when the light-emitting elements emit light beams toward the living body, a control unit that controls the light-emitting elements so that the light-emitting elements successively emit the light beams, and a measurement unit that measures living-body information at plural depths in the living body by using the reflected light beams that are successively received by the light-receiving element.

Abstract: As placement of a physiological monitoring sensor is typically at a sensor site located at an extremity of the body, the state of microcirculation, such as whether vessels are blocked or open, can have a significant effect on the readings at the sensor site. It is therefore desirable to provide a patient monitor and/or physiological monitoring sensor capable of distinguishing the microcirculation state of blood vessels. In some embodiments, the patient monitor and/or sensor provide a warning and/or compensates a measurement based on the microcirculation state. In some embodiments, a microcirculation determination process implementable by the patient monitor and/or sensor is used to determine the state of microcirculation of the patient.

Abstract: A patient monitor capable of measuring microcirculation at a tissue site includes a light source, a beam splitter, a photodetector and a patient monitor. Light emitted from the light source is split into a reference arm and a sample arm. The light in the sample arm is directed at a tissue site, such as an eyelid. The reflected light from the tissue site is interfered with the light from the reference arm. The photodetector measures the interference of the light from both the sample arm and the reference arm. The patient monitor uses the measurements from the photodetector to calculate the oxygen saturation at the tissue site and monitor the microcirculation at the tissue site.

Abstract: A system is provided for measuring and assessing hemodynamics in an anatomical structure of a subject, along with a method for image processing hemodynamics in at least a part of an anatomical structure in video images acquired from a subject. The system and method relates to measuring and assessing hemodynamics in, around and near the surface, in particular the gastrointestinal wall, of the gastrointestinal tract of a subject. A method for image processing hemodynamics in at least a part of an anatomical structure in video images acquired from a subject may performing image analysis of at least one video sequence acquired after a fluorescent contrast agent has been supplied to the subject, calculating intensity values in one or more regions of interest based on the image analysis, and determining the perfusion slope of the flow of the fluorescent contrast agent through at least one of said regions of interest.

Abstract: A method for monitoring the blood pressure of a patient, comprising the following steps: determining a pulse arrival time signal from the patient 2 based on the pulse wave velocity method; determining an accelerometer signal from the patient 2; and triggering an additional measure or deriving a blood pressure value, taking into account the pulse arrival time signal and a DC component of the accelerometer signal. In this way, a possibility for monitoring the blood pressure of a patient is provided with which false alarms and/or unnecessary additional cuff-based blood pressure measurements can be avoided.

Abstract: A microlead has a distal active portion formed by a microcable including an electrically conductive core coated with an insulation layer, with a plurality of exposed areas forming the stimulation electrodes. The microcable has a three-dimensional preshape inscribed in a cylindrical envelope volume so as to match the target vessel wall. The microcable includes a plurality of exposed areas regularly distributed over the circumference of the cylindrical envelope volume considered in axial projection, the exposed zones extending only over an angular sector of the microcable considered in cross section, said angular sector facing the outside of the envelope volume of the preshape.

Abstract: A device for detecting, monitoring and optionally recording ECG signals is disclosed. The device has at least two electrodes and an on-board memory. The electrodes can be recoatable and/or replaceable. The device can be charged wirelessly through the electrodes or by an internal energy harvesting system. A power saving mode is provided whereby the electrodes are activated by a pre-defined tapping pattern of electrical contact applied by a user and, upon activation, the device starts pairing with and transmitting ECG signals to a receiving station, e.g. a computer, a smart phone, a tablet or the like.

Abstract: The present invention relates to a physiological monitoring device. Some embodiments of the invention allow for long-term monitoring of physiological signals. Further embodiments may also allow for the monitoring of secondary signals such as motion.

Abstract: A method for constructing a stress-pliant physiological electrode assembly is provided. An electrode backing is formed from a stretchable woven textile material compatible to contact the skin on at least one surface. A pair of flexile wires is provided to serve as electrode circuit trace and electrode signal pickup. At least one of the flexile wires is sewn into the textile material which provides a stress-pliant malleability. Each of the flexile wires has an electrically-contacting area functioning for electric signal pickup. The electrically-contacting area may be sewn into the woven textile or affixed to the woven textile via conductive adhesives. The stress-pliant physiological electrode assembly is applicable for a wide array of physiological monitors, including ECG monitors, and especially is suitable for long-term wear. The method disclosed is both environmentally friendly and low-cost.

Abstract: Physiological monitoring can be provided through a lightweight wearable monitor that includes two components, a flexible extended wear electrode patch and a reusable monitor recorder that removably snaps into a receptacle on the electrode patch. The wearable monitor sits centrally (in the midline) on the patient's chest along the sternum oriented top-to-bottom. The placement of the wearable monitor in a location at the sternal midline, with its unique narrow “hourglass”-like shape, significantly improves the ability of the wearable monitor to cutaneously sense cardiac electrical potential signals, particularly the P-wave and, to a lesser extent, the QRS interval signals indicating ventricular activity in the ECG waveforms. Additionally, the monitor recorder includes an ECG sensing circuit that measures raw cutaneous electrical signals and performs signal processing prior to outputting the processed signals for sampling and storage.

Abstract: A system for providing information about a patient's heart includes one or more electrodes that receive signals from electrical activity of the heart over one or more heart beat cycles. The system is characterized by an electronic processor coupled to the one or more electrodes to: receive the signals from the one or more electrodes; execute an automated set-up routine that processes the signals to automatically provide at least some set-up results for new mapping configurations; and/or process the signals with beat detection and beat acceptance criteria for new or existing mapping configurations to provide information about how well the signals match one or more of the new or existing mapping configurations.

Abstract: A system for providing information about a patient's heart, the system including one or more catheters that receive intracardiac signals from electrical activity of the heart over one or more heart beat cycles and an electronic processor coupled to the one or more catheters. The electronic processor to: receive the intracardiac signals from the one or more catheters; preprocess the intracardiac signals to provide preprocessed signals, wherein each of the intracardiac signals is preprocessed to provide a corresponding preprocessed signal; and compare the preprocessed signals to a set of signals to determine a degree of similarity between each of the preprocessed signals and the set of signals.

Abstract: A body fat measurement device includes: a measurement unit for measuring a shape of a measurement subject's trunk area; a breathing estimation unit that detects a change over time in the measured trunk area shape and estimates the measurement subject's breathing based on the detected change; a breathing state determination unit that determines whether or not the estimated breathing of the measurement subject is in a state suited to measurement; a state output unit that outputs the estimated breathing state to the exterior in association with a result of the determination; and a fat mass calculation unit that calculates a trunk area fat mass using the body impedance measured by a body impedance measurement unit and a trunk area size based on the trunk area shape measured by the measurement unit.

Abstract: A non-invasive and accurate vagina evaluation device and uterine evaluation devices are provided that measure the receptivity (uterine implantation capacity) of the mother's body to a fertilized egg implanting itself into the uterus. A first vagina evaluation device includes: a main body stretchable and expandable after insertion into a vagina, followed by air injection thereinto; four electrodes brought into contact with the vagina wall as the main body expands and stretches; and fixation means configured to fix the interval of arrangement of the electrodes. Second and third uterine evaluation device include: a flexible and rod-shaped main body for insertion into a uterine cavity; and four or two impedance electrodes arranged with a predetermined interval therebetween in an insertion direction of the main body and brought into contact with an endometrium of the uterine cavity to measure a uterine endometrial impedance generated between the endometrium and each of the electrodes.

Abstract: A catheter is responsive to external and internal magnetic field generators for generating position data of the catheter position and pressure data to determine pressured exerted on a distal end of the catheter when engaged with tissue, with a reduced number of sensing coils and reduced number of sensing coil leads for minimizing lead breakage and failure. The catheter includes a distal section adapted for engagement with patient tissue, where the distal section has a proximal portion, a distal portion and a flexible joint with a resilient member adapted to allow axial displacement and angular deflection between the proximal and distal portions of the distal section. The catheter may have three or less sensing coils with three or less leads, each transmitting signals between a respective sensing coil and the signal processor.

Abstract: Devices and methods obtain and use endovascular electrograms (or electrocardiograms/ECGs) in a number of clinical applications and settings. In one embodiment, a method for locating an indwelling medical device within a vasculature of a patient includes identifying an endovascular ECG waveform complex from an endovascular ECG signal associated with the indwelling medical device, then calculating an absolute value of the energy of the endovascular ECG waveform complex over a predetermined segment thereof. A position of the medical device within the vasculature is then determined by observation of the absolute value of the energy of the predetermined segment of the endovascular ECG waveform complex.