Abstract: A medical diagnostic and communications apparatus with audio output comprises an electronic processor for processing stethoscope signals and secondary audio signals. An electronic stethoscope sensor is contained within a housing for transducing body sounds to electronic signals, and is operatively connected to the electronic processor. One or more secondary audio signal sources operatively connects to the electronic processor. A common audio output is connected to electronic processor to convert electronic stethoscope signals or secondary audio signals to acoustic output. These sounds may be produced separately or mixed.

Abstract: Methods and systems for simulating a phonocardiogram (PCG) signal that includes an anomalous condition are provided. The method generates pressure and flow signals from a lumped-parameter heart model responsive to anomaly parameters. The anomaly parameters represent the anomalous condition. A timing profile or the timing profile and an amplitude profile are extracted from at least one of the generated pressure and flow signals. An anomalous signal is generated using the anomaly parameters and the extracted timing profile or timing profile and amplitude profile. The anomalous signal is time-aligned and combined with a predetermined non-anomalous signal to represent the PCG signal.

Abstract: An auscultation system includes a transducer for generating an acoustic signal at a transducing location of the subject, and a sensor for receiving an attenuated acoustic signal at a sensing location of the subject. The attenuated signal received at the sensing location is digitized, and may be analyzed in the frequency and/or time domain. The comparison of the digitized attenuated signal against the initial transduced signal allows for the computation of the degree of acoustic attenuation between the transducing and sensing locations. Acoustic attenuation may be utilized to generate an intensity ratio. The ejection fraction of the heart subject may then be computed by correlation to the intensity ratio. Pulse echo methods are also disclosed. The echo transducer is oriented on the subject and generates a series of signal pulses. The return echo on the pulse is then received and a brightness encoded image is produced.

Abstract: A tool for neurological and diagnostic testing comprises the combination of a stethoscope with a reflex hammer including a light. When mounted on the stethoscope head the reflex hammer extends beyond the head, without interfering with the normal use of the stethoscope. A handle, which may or may not be joined to the reflex hammer, is positioned on the flexible stethoscope tubing and provides a gripping surface for using the tool for neurological testing. One embodiment includes a light within the reflex hammer, so that a light is available for testing responses to light at the same time as checking other responses. The reflex hammer and light combination is adaptable for use with binaural and electronic stethoscopes, thus providing a convenient set of instruments within a single device. A detent on the handle provides an ergonomic grip, or a place for inclusion of indicia.

Abstract: A catheter terminates at a tip that includes an array of pressure sensors. The sensors are responsive to detect and alert the user to variations of pressure that indicate the tip is either encountering an obstruction or constriction of smaller diameter than the catheter, as well as to guide the catheter through the conduit into which it is being inserted.

Abstract: Techniques are described for analyzing auscultatory sounds to aid a medical professional in diagnosing physiological conditions of a patient. A data analysis system, for example, applies singular value decomposition to auscultatory sounds associated known physiological conditions to define a set of one or more disease regions within a multidimensional space. A diagnostic device, such as an electronic stethoscope or personal digital assistant, applies configuration data from the data analysis system to generate a set of one or more vectors within the multidimensional space representative of auscultatory sounds associated with a patient. The diagnostic device outputs a diagnostic message associated with a physiological condition of the patient based on the orientation of the vectors relative to the disease regions within the multidimensional space.

Abstract: Apparatus and associated methodology for monitoring correlatable anatomical electrical and sound signals, such as electrical and audio signals produced by human heart activity, including (a) attaching to a selected, common anatomical site ECG (or other) electrode structure, and a multi-axial sound sensor, and (b) simultaneously collecting from adjacent that site both ECG(or other)-electrical and sound signals, where such sound signals arrive adjacent the site along multiple, angularly intersecting axes.

Abstract: An apparatus to enable health care providers to perform a number of diagnostic procedures, including listening to the heart, obtaining electrocardiograms and sonograms. A pocket size instrument displays an EKG tracing on its screen simultaneously upon auscultation of the heart. The abdomen may also be investigated by displaying a sonogram. Wireless broadband technology may provide a closed circuit interface for real-time wireless transmission of acquired data. Examination requires none of a multiplicity of wires to untangle, bulky machines or a technician to be summoned. Regurgitation, heart size, ischemia and heart murmurs can all be evaluated by a visual and auditory methods.

Abstract: A handheld auscultatory scanner continuously obtains a heart sound signal from a patient, using a noninvasive passive acoustic sensor, allowing free-form protocol, analysis and display of the heart sound signal on a handheld processing unit in a graphical manner such that a single heart cycle is displayed in a synchronized manner, along with summary results of the processing of the acoustic signal. The results are presented in terms of standard auscultatory findings. The combination of summary findings, heart sound display and audible signal provides a method for assisting in patient screening for heart conditions and for teaching auscultation techniques.

Abstract: A non-invasive diagnostic tool and method for detecting an obstruction in a coronary artery, the diagnostic tool including a signal processor adapted to receive signals corresponding to a heart beat from a plurality of acoustic sensors attached to the chest of a patient. The signal processor is programmed to identify a diastolic portion of the signals for a plurality of heartbeats and conduct a wavelet transform analysis on the diastolic signals for determining the existence of, as well as the severity and the location of, an obstruction in a coronary artery of the patient.

Abstract: A method and apparatus are disclosed for treating mitral regurgitation with electrical stimulation. By providing pacing stimulation to the left atrium during ventricular systole, a beneficial effect is obtained which can prevent or reduce the extent of mitral regurgitation.

Abstract: A cardiac rhythm management system provides a phonocardiographic image indicative of a heart's mechanical events related to hemodynamic performance. The phonocardiographic image includes a stack of acoustic sensor signal segments representing multiple cardiac cycles. Each acoustic sensor signal segment includes heart sounds indicative of the heart's mechanical events and representations of the heart's electrical events. The stack of acoustic sensor signal segments are aligned by a selected type of the heart's mechanical or electrical events and are grouped by a cardiac timing parameter for presentation.

Abstract: An implantable medical device includes a dual-use sensor such as a single accelerometer that senses an acceleration signal. A sensor processing circuit processes the acceleration signal to produce an activity level signal and a heart sound signal. The implantable medical device provides for rate responsive pacing in which at least one pacing parameter, such as the pacing interval, is dynamically adjusted based on the physical activity level. The implantable medical device also uses the heart sounds for pacing control purposes or transmits a heart sound signal to an external system for pacing control and/or diagnostic purposes.

Abstract: A method and system for providing online health monitoring and accumulating data from patients worldwide, wherein a database for storing a plurality of health statuses of a plurality of users is established, wherein the database is centrally-accessible from the Internet; data corresponding to a health statistic of a user is received from the user, the data being generated by a health monitoring device; the health statistic is analyzed to determine a health status from the health statistic; the health status is stored in the database; and a population statistic is updated based on the health status and the plurality of health statuses. Such monitoring is particularly useful for both diagnosing and prescribing preventive medical treatment, and is particularly suited for the field of cardiovascular health care.

Abstract: A cardiac rhythm management system provides for assessment of cardiac mechanical dyssynchrony based on heart sound morphology and optimization of pacing parameters based on the effect of pacing on the cardiac mechanical dyssynchrony assessment. A degree of cardiac mechanical dyssynchrony is measured by the time delay between tricuspid valve closure and mitral valve closure and/or the time delay between pulmonary valve closure and aortic valve closure. A cardiac resynchronization therapy is optimized by determining therapy parameters to provide an approximately minimum degree of cardiac mechanical dyssynchrony by cardiac pacing.

Abstract: A cordless stethoscope for use in hazardous material environments comprising a fluid tight hand held sound sensing device having a stethoscope head for sensing auscultatory sounds, a transmitter for transmitting sounds sensed by the device, a receiver for receiving transmissions from the transmitter and an ear piece for converting the received transmissions into audible sound. The housing is sized and shaped for being grasped by a gloved hand and is fluid tight for decontamination purposes. The sound sensing device may further comprise a microphone for sensing otherwise inaudible voice communications from a patient. The transmitter and receiver preferably uses magnetic induction transmissions to transmit sounds through barriers such as hazardous material suits that may be worn by clinicians during treatment of patients in possible hazardous material situations.

Abstract: A method and a system for monitoring and characterizing a person's heart condition for various medically related purposes. The method includes the steps of (a) acquiring a selected person's acoustic heart signature, (b) acquiring, substantially simultaneously, that same person's electrical heart signature, (c) choosing elements of determined interest from these two acquired signatures and selectively processing and inter- and/or cross-relating such elements, and (d) employing the results of the relating step to create a heart-condition fingerprint useful in the characterization of that person's heart condition.

Abstract: Methods and systems for determining cardiovascular parameters of a patient. In an exemplary embodiment, the method includes placing a phonocardiogram sensor on a patient's body at a first distal location to the heart, and a blood-pressure waveform sensor at a second distal location to the heart. Then, a first set and a second set of waveforms is obtained from the phonocardiogram sensor and the blood-pressure waveform sensor, respectively. A signal processing or conditioning operation may optionally be performed using the first and second sets of waveforms. Then, a time delay between a dicrotic notch signal and an S2 signal is determined. A blood pressure pulse transit time value is calculated by adding S2D, representing a time delay between a patient's heart valve closure time and an arrival time of the S2 signal at the first distal location, to the time delay between a dicrotic notch signal and an S2 signal.

Abstract: Techniques are provided for performing internal measurement of heart sounds to estimate patient cardiac function in terms of stroke volume, cardiac output, or a maximum rate of change of aortic pressure with time (max dP/dt). Control parameters of the medical device are then automatically adjusted so as to optimize overall cardiac function or to provide for ventricular resynchronization therapy. In one example, heart sound signals are derived from acceleration signals received from an accelerometer. The heart sound signals are analyzed to identify S1 and S2 heart sounds as well as ejection period and isovolumic interval (ISOV). Proxies for max dP/dt, stroke volume and cardiac output are then derived from the S1 and S2 heart sounds, the ejection period and the ISOV. Alternative techniques, not requiring detection of ISOV, are employed for use if the patient has heart value regurgitation.

Abstract: This invention concerns a method and system for automatically determining heart rate. The invention can be applied to determining the heart of any animal including humans. The method involves sensing body sounds and transducing them to electrical signals. Digitizing the electrical signals. Emphasizing the heart sound maxima (S1 and S2 signals) relative to noise by filtering, decompression and squaring. Detecting local maxima in the signals as likely S1 signals and generating a threshold amplitude. Selecting maxima that exceed the threshold as surviving likely candidate S1 signals. Screening the surviving candidate S1 against physiologically derived criteria. And, calculating the heart rate from the screened S1.

Abstract: A cardiac rhythm management system provides for the trending of a third heart sound (S3) index. The S3 index is a ratio, or an estimate of the ratio, of the number of S3 beats to the number of all heart beats, where the S3 beats are each a heart beat during which an occurrence of S3 is detected. An implantable sensor such as an accelerometer or a microphone senses an acoustic signal indicative heart sounds including S3. An S3 detector detects occurrences of S3 from the acoustic signal. A heart sound processing system trends the S3 index on a periodic basis to allow continuous monitoring of the S3 activity level, which is indicative of conditions related to heart failure.

Abstract: A cardiac rhythm management device is configured to detect oscillations in cardiac rhythm by measuring the amplitudes of heart sounds during successive heart beats. Upon detection of acoustic alternans, the device may adjust its operating behavior to compensate for the deleterious effects of the condition.

Abstract: A combined audio and electrical anatomy-signal sensor which is designed to collect, essentially from a selected, common anatomical site, related audio and electrical anatomical signals, such as heart-produced signals. The sensor includes a unique body structure which is designed to function both as a part of the audio-information gathering structure, and as a part of electrical electrode structure for gathering electrical signals. Chamber space is provided within this body for receiving and containing desired electrical circuitry, in the form of circuit-board-supported electrical components, which may be designed to perform any one of a number of different functions relative to signal gathering and transferring at and from an anatomical site.

Abstract: In a method of noninvasive measurement of parameters of diastolic function of left ventricle and automated evaluation of the measured profile at rest and with exercise, a patient performs an isometric exercise. An external pressure sensor and heart sounds microphone are applied in a non-invasive manner on the thoracic wall to obtain a left ventricular pressure mirroring curve (pressocardiogram) and simultaneously the heart sounds (phonocardiogram). An external unit determines and calculates characteristic diastolic parameters derived from the pressocardiographic curve and phonocardiogram at rest, during and after exercise, converts each said pressocardiogram into a digital waveform in the time domain, and automatically categorizes the mentioned characteristic parameters based on exact categorization criteria for defining several differentialforms of diastolic dysfunction of left ventricle in human beings.

Abstract: A method and system for automatically detecting heart sounds. The sound system receives sound data corresponding to beats of the heart. The sound system analyzes the sound data to detect the presence of a heart sound within the beats. The sound system then outputs an indication of the heart sounds that were detected. The sound system may use ECG data to identify various locations (e.g., R peak) within a beat and use those locations to assist in the detection of heart sounds.

Abstract: An implantable cardiac stimulator including and accelerometer utilizes heart sound measurements to optimize the AV delay. One or more of the amplitude of the heart sound, the pre-ejection interval or the ejection interval is derived from the measurements and examined at various values of AV delay. The optimal AV delay is selected that corresponds to the highest cardiac function such as contractility, cardiac output and stroke volume. The stimulation device determines when the patient is at rest and the accelerometer provides a signal that corresponds to the audible component of a vibration produced as a result of ventricular contraction, blood movement toward the atrium, and the opening and closing of valves. The AV delay is adjusted within a range of values and the cardiac parameters are determined multiple times for each AV delay value. The average value of the cardiac parameter is examined to determine the optimal AV delay value.

Abstract: A method and apparatus for gathering high-quality anatomical audio signals. Practice of the invention, which is illustrated herein in the context of heart-produced signals, is based upon gathering, and competitively processing audio signals collected simultaneously from two adjacent anatomical sites. Competitive processing examines these two signals in light of certain selected “quality” parameters, and thereby selects the better signal at a user-selected point in time.

Abstract: A cardiac rhythm management system includes an operational mode in which ventricular pacing pulses are delivered at a rate that tracks a sinoatrial rate up to an appropriate maximum atrial tracking rate (MATR) value determined by the system. In one example, the MATR value is based on a patient activity level and a hemodynamic maximum rate (HMR) determined from a QRS-to-S2 interval, where S2 is an accelerometer-generated fiducial correlative to aortic valve closure (AVC). In a further example, a correlation between the QRS-to-S2 interval and heart rate is established, and the MATR is based on the patient activity level and heart rate. In a further example, a lower rate threshold for providing antitachyarrhythmia therapy is modified based on the MATR. For example, when the MATR exceeds a default value of the antitachyarrhythmia therapy lower rate threshold, the threshold tracks the MATR.

Abstract: An apparatus for outputting heart sounds includes an implantable system and an external system. The implantable system includes a sensor for generating sensed signals representing detected heart sounds, an interface circuit and a control circuit for receiving the sensed signals, generating data representing the heart sounds therefrom, and transmitting the data to the external system via the interface circuit. The external system includes an interface circuit for communicating with the implantable system, and a control circuit for receiving the data representing the heart sounds and for generating control signals that cause an output device to generate outputs representing the sounds. The implantable system may also include a sensor(s) for detecting cardiac electrical signals. In this case, outputs representing the cardiac electrical signals are also output.

Abstract: The invention provides a stethoscope device comprising a chest piece, an amplifier and a mixer compatible with a conventional voice quality telephone system. Electrical signals are generated that are representative of physiological sounds such as breath sounds, heart sounds and bowel sounds. The electrical signals can be combined with voice communications at the remote site and transmitted over the telephone system. The invention also provides a system and method for diagnosis by a trained health care professional with the patient being located at a remote site. In another embodiment, the invention also provides a system and method for training students to interpret stethoscope sounds. In addition, the system allows for simultaneous listening by the health care professional and another individual at the remote location of the stethoscope.

Abstract: The method of presenting concurrent information about the electrical and mechanical activity of the heart using non-invasively obtained electrical and mechanical cardiac activity data from the chest or thorax of a patient comprises the steps of: placing at least three active Laplacian ECG sensors at locations on the chest or thorax of the patient; where each sensor has at least one outer ring element and an inner solid circle element, placing at least one ultrasonic sensor on the thorax where there is no underlying bone structure, only tissue, and utilizing available ultrasound technology to produce two or three-dimensional displays of the moving surface of the heart and making direct measurements of the exact sites of the sensors on the chest surface to determine the position and distance from the center of each sensor to the heart along a line orthogonal to the plane of the sensor and create a virtual heart surface; updating the measurements at a rate to show the movement of the heart's surface; monitoring

Abstract: The use of two separate ensemble averagers for processing a detected waveform for use in calculating oxygen saturation and a pulse rate. The ensemble averager used for calculating oxygen saturation operates on a signal which has been normalized, while the ensemble averager for the pulse rate calculation operates on a signal which has not been normalized. The metrics chosen for the two paths through the two ensemble averagers can be varied to optimize the ensemble averaging for oxygen saturation or pulse rate calculations.

Abstract: A light transmitting device for attachment to a stethoscope headpiece which provides for reversible engagement of the device to the headpiece so that the same can be removed such as for repairs or replacement of batteries. The transmitting device provides a source of light without interfering with the operation of the stethoscope and can be provided without retooling the stethoscope to accommodate a source of light.

Abstract: An apparatus for detecting a heart sound of a living subject, including a pressure-pulse-wave sensor which is adapted to be worn on a body portion of the subject that is distant from a chest of the subject, detects a pressure pulse wave produced by an artery of the body portion, and generates a pressure-pulse-wave signal representing the detected pressure pulse wave; and a heart-sound extracting device for extracting, from the pressure-pulse-wave signal generated by the pressure-pulse-wave sensor, a heart-sound component representing the heart sound of the subject.

Abstract: A sensor designed to collect and convey single-site-related, body-produced electrical and acoustic signals, such as those related to heart activity, where electrical electrode and audio transducer structures lie along a common axis. A portion of the electrical electrode structure forms an acoustic isolating shroud around the audio transducer.

Abstract: A method of diagnosing pathologic heart conditions in which a time series of heart sounds is filtered and parsed into a sequence of individual heart cycles. A systolic interval as well as systolic sub-intervals are identified for each heart cycle. The systolic intervals and ECG peaks are then digitally filtered to optimize for click detection. For each heartcycle, systole time limits are determined, a time series of the transform at specific wavelet scales are input to a Neyman-Pearson “constant false alarm rate” (CFAR) detector to identify anomalously high wavelet coefficients, and a vector of detections vs. time is created. The series of anomalously high detections (one series for each heart cycle) are then assembled into a matrix and convolved with an averaging vector yielding detection statistics across heart cycles and time intervals consistent with an observed spread of click occurrence times.

Abstract: A method of processing a signal representing an input sound signal is disclosed. The signal is divided in time into a plurality of signal segments, each having an individual duration of time. The signal segments are processed into an output signal of successive signal segments in such a way that at least one, preferably all, of the signal segments are repeated immediately and successively at least once in the output signal. Each signal segment is established in such a way that the duration of time of a majority, preferably all, of the signal segments is less than 60 ms. Thus, a sound signal can be reduced in speed by doubling the number of short cycles.

Abstract: The invention is directed to an implantable medical device (IMD) that includes an accelerometer. The accelerometer is used to detect heart tones associated with blood flow through one or more cardiac valves. In particular, the IMD measures durations of the heart tones detected by the accelerometer, and uses the measured durations to identify deterioration of the heart. In this manner, the IMD facilitates early detection of cardiac deterioration so that proper therapy can be delivered to the patient to remedy and combat such deterioration.

Abstract: A biophysical sensor including a sound vibration sensing element (12) to produce a sensed output, and two or more separate signal processing paths to process the sensed outputs to produce output signals. The output signals may reflect specific frequency bands within the raw biological signal. In a further aspect the invention concerns an electronic stethoscope in which the sound vibration sensing element (12) is a PVDF membrane, the signal processing involves an operational amplifier (OP amp) (10) connected to the PVDF membrane, and a unity gain buffer amplifier is connected to the output of the OP amp to allow the connection of headphones directly to the sensor output.

Abstract: A tool for neurological and diagnostic testing comprises the combination of a stethoscope with a reflex hammer. When mounted on the stethoscope head the reflex hammer extends beyond the head, without interfering with the normal use of the stethoscope. A handle, which may or may not be joined to the reflex hammer, is positioned on the flexible stethoscope tubing and provides a gripping surface for using the tool for neurological testing. One embodiment has an opening between the reflex hammer body and the handle enabling the user to grasp and rotate the stethoscope head. The reflex hammer, which can be made from one or more members, is adaptable for use with binaural and electronic stethoscopes. A detent on the handle provides an ergonomic grip, or a place for inclusion of indicia.

Abstract: A method for extracting and evaluating features from cardiac acoustic signals includes the steps of obtaining a cardiac acoustic signal, extracting physiologically significant features from the cardiac acoustic signal using a neural network, analyzing the cardiac acoustic signal with a wavelist decomposition to extract time-frequency information, and identifying basic heart sounds using neutral networks applied to the extracted time-frequency information. A method for determining a status of heart murmurs includes the steps of obtaining a cardiac acoustic signal, detecting a murmur, if any, from the cardiac acoustic signal, and determining whether the murmur is one of functional and pathological based upon expert rules.

Abstract: Physiological condition monitors utilizing very low frequency acoustic signals and signals indicative of body orientation are disclosed. The physiological condition monitors comprise a sensor that is capable of detecting low frequency acoustic signals in the frequency range of one tenth Hertz to thirty Hertz. The sensor comprises a chamber having portions that form a cavity and a low frequency microphone placed within the cavity. An alternate embodiment of the invention comprises a chamber having portions that form a resonant cavity, a microphone mounted in the resonant cavity, and a membrane that covers the resonant cavity. Low frequency acoustic signals that are incident on the membrane cause the membrane to move and amplify the acoustic signals within the resonant cavity. The sensor provides information concerning physiological conditions, such as respiration and cardiac activity. The sensor in a physiological condition monitor does not need to be directly coupled to the skin of the person being monitored.

Abstract: A light transmitting device for attachment to a stethoscope headpiece which provides for reversible engagement of the device to the headpiece so that the same can be removed such as for repairs or replacement of batteries. The transmitting device provides a source of light without interfering with the operation of the stethoscope and can be provided without retooling the stethoscope to accommodate a source of light.

Abstract: A stethoscope includes a pair of branches, each having a bent clip tube section with a coupling end portion connected to an ear tube section, and a curved intermediate fulcrum portion, which interconnects the coupling end portion and a resilient operating end portion and which has a concave outer surface that faces away from the other branch, and a convex inner surface that faces toward the other branch. A rubber tube is connected to the operating end portions of the clip tube sections of the branches and is in fluid communication with the branches. The intermediate fulcrum portions abut against each other. The operating end portions form a press space therebetween, and are depressible toward each other when removing the ear tube sections from the ears of the wearer.

Abstract: An apparatus according to an embodiment of the present invention is provided for sensing acoustic signals. The apparatus includes a housing having an apertured posterior member, a sensing unit extending through the apertured posterior member for interfacing by contact with a patient, a cursor control for positioning a cursor on a display, the display located anteriorially on the housing, a button for fixing a position of the cursor in the display, indicating the position on the housing with respect to the patient, and a circuit for causing the cursor to move about the display in response to the cursor control, and for transmitting the acoustic signal.

Abstract: An esophageal stethoscope includes a tubular flexible body having an acoustic input region. A carrier member, which is separate from the tubular flexible body, is selectively engageable with the tubular flexible body either proximally or distally of the acoustic input region. The carrier member carries one or more devices for providing esophageal recording, monitoring or stimulation functions. For transesophageal cardiac pacing, electrodes are mounted to the carrier member such that engagement of the carrier member with the tubular flexible body functions to convert the esophageal stethoscope to a pacing stethoscope. To carry out a sensing, recording or monitoring function, such as esophageal oximetry, one or more oximetry probes are mounted to the carrier member such that engagement of the carrier member with the esophageal stethoscope converts the stethoscope for use in an oximetry sensing application.

Abstract: A medical unit including a unit main body having an upper face and a circuit therein. The unit main body further including an input means arranged on the upper face and connected to the circuit, and a connected section arranged on the upper face to which the connector section of an external device is connected. Preferably, the medical unit includes: an ultrasonic probe having a probe element at its distal end and an electrical connection section at its proximal end; and an ultrasonic diagnostic unit main body having an upper face and a circuit therein for processing ultrasonic signals transmitted from said ultrasonic probe element, said ultrasonic unit main body further including an input means arranged on said upper face and connected to said circuit, and a connected section arranged on said upper face to which said electrical connection section is connected.

Abstract: A minimally invasive, implantable heart sound and ECG monitor and associated method for deriving blood pressure from heart sound data. The device is equipped with an acoustical sensor for detecting first and second heart sounds which are sampled and stored during sensing windows following R-wave and T-wave detections, respectively. ECG and heart sound data are stored in a continuous, looping memory, and segments of data are stored in long-term memory upon an automatic or manual data storage triggering event. Estimated blood pressure is calculated based on custom spectral analysis and processing of the first and second heart sounds. A calibration method includes measuring a patient's blood pressure using a standard clinical method and performing regression analysis on multiple spectral variables to identify a set of best fit weighted equations for predicting blood pressure. Concurrent ECG and estimated blood pressure may be displayed for review by a physician.

Abstract: An esophageal stethoscope includes a tubular flexible body having an acoustic input region. A carrier member, which is separate from the tubular flexible body, is selectively engageable with the tubular flexible body either proximally or distally of the acoustic input region. The carrier member carries one or more devices for providing esophageal recording, monitoring or stimulation functions. For transesophageal cardiac pacing, electrodes are mounted to the carrier member such that engagement of the carrier member with the tubular flexible body functions to convert the esophageal stethoscope to a pacing stethoscope. To carry out a sensing, recording or monitoring function, such as esophageal oximetry, one or more oximetry probes are mounted to the carrier member such that engagement of the carrier member with the esophageal stethoscope converts the stethoscope for use in an oximetry sensing application.

Abstract: A device and a method of sensing and transmitting physiological pressures and body temperatures are disclosed. The device includes a transducer and a transmitter. The transmitter is adapted to broadcast a signal which is modulated by the output of a transducer. The transmitter is also adapted to limit the power of the output signal. The method includes transducing a physiological parameter and broadcasting a signal which is modulated by the transduced parameter. The power of the output signal is limited so that the signal will attenuate within a predetermined distance.