Abstract: A protective device for an EKG monitor for use in surgical electrocautery which employs an electrocautery surgical knife supplied with radio frequency power and an EKG monitoring apparatus having an input and including a scope providing an EKG display. Electrodes are provided for attachment to a surgical patient and are connected to the apparatus by the protective device, which includes a radio frequency detector and disabling apparatus which removes signal from the EKG monitor input in the presence of radio frequency energy.
Abstract: A method for generating audio information to indicate the presence and nature of a cardiac rhythm disturbance is disclosed. More specifically, this method produces sounds which accompany atrial and ventricular ectopic rhythms, allowing the physician to appreciate the presence of such rhythms without having to visually inspect the morphology of the electrocardiogram signal. Furthermore, the sounds differ according to the type of ectopic rhythm present. This method provides such information in real time, allowing the physician to correlate the information with the current condition of the patient. The electrocardiogram signal is analyzed by a microprocessor or microcomputer which in turn controls a tone generator to produce the audio output.
Abstract: A rapid, noninvasive technique for quantifying the dynamic response of the autonomic nervous system (ANS) to perturbations it senses over a broad range of physiologically relevant frequencies. The technique involves two steps. First, a physiologic parameter sensed by the ANS is subjected to a broad-band perturbation as an input signal while a physiologic parameter modulated by the ANS is monitored as an output signal. Then, the transfer relation between input signal and output signal is determined. The computed transfer relation is then readily interpretable in terms of responsiveness of the various limbs of the ANS.
August 18, 1986
Date of Patent:
October 18, 1988
Massachusetts Institute of Technology
Ronald D. Berger, Jerome P. Saul, Ming H. Chen, Richard J. Cohen
Abstract: A toy having an element which forms a message such that a person under its influence feels an urge to fall asleep, and a sending element which senses a signal from the person when he or she does not sleep and then activates the message forming element, so that the latter not only tells stories or fairy tales but also puts a user to sleep. One of the messages can be a lullaby. The toy can also be actuated by the pulse beat of the user, and the pulse beat data can be displayed so that the toy simultanesouly serves as a medical instrument.
Abstract: A cardiac pacer, which generates pacing pulses at a predetermined basic pacing rate, includes a device for sensing physical activity and for generating a control signal dependent thereon, a device for varying the predetermined basic pacing rate independent on the control signal and a device for forcing the pacing rate back to a lower rate if the pacing rate runs at or above a predetermined high rate for a predetermined time period.
Abstract: A cardiac pacer is described which includes a pulse generator for providing pacing pulses and an electrical lead for bilateral (or bidirectional) (i.e., sense and pace) connection to a chamber of the heart. A fixed gain, tuned sensing amplifier senses selected activity of the heart chamber. The output of the sensing amplifier is connected to a pair of voltage comparators. One of the voltage comparators has a slightly lower threshold and thus a slightly higher sensitivity level than the other voltage comparator. Under closed loop control, the thresholds of the respective voltage comparators are automatically adjusted so that one of the voltage comparators will sense the selected activity of the heart chamber and the other voltage comparator will not sense the selected activity.
Abstract: A cardiac pacer is provided which includes a pulse generator for providing pacing pulses and an electrical lead for connection to a chamber of the heart. A pair of separate sensing amplifiers sense selected activity of the heart chamber. One of the sensing amplifiers has a slightly lower threshold and thus a slightly higher sensitivity level than the other sensing amplifier. The thresholds of the respective sensing amplifiers are automatically adjusted so that the first sensing amplifier will sense the selected activity of the heart chamber and the other sensing amplifier will not sense the selected activity.
Abstract: A heart pacemaker for supplying pacing signals to a heart includes circuitry for controlling operation of the pacemaker in dependence upon the occurrence of heart sounds. The pacemaker includes a detector for such sounds and circuitry for generating a control signal therefrom which is supplied to the basic pacing circuitry.
Abstract: The medical current limiting circuit is for use with medical electrodes and associated diagnostic and therapeutic apparatus. The device protects the apparatus and patient from current flow. The device has circuitry comprising a pair of external connectors, a pair of n-type field effect transistors connected in cascade, a resistor, a p-type field effect transistor, a capacitor to latch the p-FET in a non-conductive state upon its initial activation and a diode to prevent capacitor discharge to the current source.
Abstract: An atrium-controlled heart pacemaker has a monitoring circuit for interrupting tachycardia which may be generated by the pacemaker. The monitoring circuit includes a P-wave counter and a window generator connected thereto. The window generator prescribes a window for the P-wave counter within which a predetermined maximum number n of P-waves is allowed to appear. When the n.sup.th P-wave appears in the window, forwarding of the n+1.sup.th P-wave to the stimulation circuit is blocked.
Abstract: A monitoring system for providing continuous monitoring of a patient, including periods of transport, includes a data acquisition and processing module receiving physiological data from the patient. The module may be inserted in a bedside display unit to display the physiological condition data being monitored. The module may also be inserted in a portable display unit that can accompany the patient during transport. Connectors permit the module to simultaneously drive both the display units so that no data is lost when the module is removed from the bedside unit and placed in the portable unit and vice versa.
September 26, 1986
Date of Patent:
December 29, 1987
Marquette Electronics, Inc.
Michael J. Cudahy, Carlos De La Huerga, Harold N. Arneson, R. Thomas Divers, Barry J. Altman
Abstract: A cardiac pacer which generates pacing pulses at a predetermined pacing rate includes a device for processing the pacing pulses according to an impedance measurement such that a respiratory signal is obtained. The predetermined pacing rate is then varied dependent on the respiratory signal.
Abstract: A heart pacemaker has circuitry for forming an electrical signal corresponding to the electrode impedance of the pacemaker. The signal is formed by monitoring the stimulation current and the stimulation voltage and dividing those values by each other in a divider. This impedance signal is a measure of the respiration rate of the pacemaker user, and is employed for controlling the pulse rate of the pulse generator of the heart pacemaker in accordance therewith.