Abstract:
57 A pocket-sized, self-contained electrocardiogram monitor with a dot-matrix, liquid-crystal display. The monitor uses dry electrodes and is suitable for direct placement against the patient's chest without the use of paste or gel to insure electrical contact. An A/D converter converts an ECG signal to a digital signal which is then processed by a microprocessor and then displayed on the liquid-crystal display in real time. The microprocessor is programmed to select the maximum and minimum digital values from four consecutive samples from the A/D converter and to supply data representative of the maximum and minimum values to the display at one-fourth the conversion sampling rate.
Abstract:
A combined spiral EKG electrode and pH probe for use in monitoring a fetus during labor is described. The combined probe includes a spiral wound needle which acts as an EKG electrode and also houses a fiber optic pH probe. Optical fibers and wires from the needle as well as from a reference electrode on the probe assembly are passed back through the cervix and vagina of a woman in order to provide simultaneous information as to both EKG and pH of the fetus during labor.
Abstract:
A medical instrument for monitoring foetal heart rate and having an electrode for insertion by rotation in the foetal head, and a torque limiting device for preventing over- penetration of the electrode. The torque limiting device is preferably a helical spring rotatable with the electrode at low torque and arranged to disengage from frictional driving contact at the torque limit.
Abstract:
A continuity detection method and apparatus for use in a system for monitoring a patient's EKG signal and estimating heartbeat rate including continuity detection apparatus for continuously monitoring electrical continuity between to EKG electrodes contacting the patient to inhibit the system from its measuring of heartbeat intervals whenever poor continuity is detected.
Abstract:
A pacer subsystem for detecting the existence of tachyarrhythmia including means for measuring the average time interval between successive heart beats and for comparing a sample beat with both a percentage of this average, and with a preset time interval. If the sample beat period is less than both criteria, it is classified as a tachy beat. If the sample beat is longer than either time interval it is classified as a non-tachy beat. Sequences of tachy beats are used to initiate an appropriate therapeutic stimulation regime. The pacer includes a central processing unit 18 and real time controller 22 connected to the heart by lead system 14 and providing functions such as timing, sensing and generating output pulses.
Abstract:
An improved micro electrode comprises a tapering capillary tube in which the wide end is preferably of outside diameter 2 mm or less, a conductive filament, preferably of outside diameter 50 µm or less, an outer lead wire and an insulating resin filler which is packed into the cavity of the capillary tube. There is a direct connection between the conductive filament and the outer lead wire in the cavity of the capillary tube. The production method may include the step of threading the conductive filament into the tapering capillary tube so that the tip of the filament projects from the thin end of the capillary tube after filling at least part of the cavity of the capillary tube with a volatile solvent to facilitate such threading.
Abstract:
To separate electrolyte (70) within a chamber (66) formed beneath a dome-like housing (34) of a skin electrode from a signal transmission connector (34). and thus prevent corrosion of the terminal portion (38, 40) exposed to the interior of the chamber by the electrolyte, the interior of the chamber (66) is subdivided into two chambers (166a. 266a), by stretching a membrane (102) thereacross, the membrane (102) being ruptured upon depression of the contact terminal (34) of the housing. the electrolyte is retained solely within the chamber (266a) separate from the intenor portion (38. 40) of the terminal so that the corrosive influence of the electrolyte is prevented from attacking the metal of the terminal prior to use of the electrode, and during storage Preferably the chamber (166a) to which also the terminal is exposed may retain other liquids which are inert with respect to the electrode, and which. preferably are also separated from the electrolyte. such as a surfactant (170) to, additional- ly, permit a wider choice of respectively, electrolytes and surfactants without unintended leakage of electrolyte through the microporous membrane (26) closing off the housing instead of the membrane (102) a plastics bag may enclose the electrolyte within the chamber (66).
Abstract:
The invention relates to a device and a method for determining sleep profiles. The aim of the invention is to develop a device and a method which automatically generate a sleep stage classification with a grading of approximately 85 % (measured according to the crosscorrelation function between automatically and manually generated sleep profiles) with negligible discomfort to the sleeper caused by additional technical equipment in his or her ordinary environment. The inventive device is characterized in that an electrode strip with a preamplifier (active electrode) working on the basis of a single frontal EEG channel is placed symmetrical to the nose root and is connected to a measuring and analysis unit controlled by a microprocessor and working autonomously. The method is characterized in that the EEG signal is compressed according to characteristics, stored and transmitted to a computer after this preprocessing, and classification according to sleep stages occurs in the computer by means of a population of neuronal networks.