Medical subject monitoring systems

• US 3,910,257 A
• Filed: 04/25/1973
• Issued: 10/07/1975
• Est. Priority Date: 04/25/1973
• Status: Expired due to Term

• Current Assignee: Donald W. Mangold, Fletcher James C Administrator of The National Aeronautics and Space Administration With Respect To An Invention of, Garry J. Cleveland, George M. Loh, Howard L. Petersen, Marko I. Lipanovich, Norman Belasco, Robert S. Luce, Sam L. Pool
• Original Assignee: Donald W. Mangold, Fletcher James C Administrator of The National Aeronautics and Space Administration With Respect To An Invention of, Garry J. Cleveland, George M. Loh, Howard L. Petersen, Marko I. Lipanovich, Norman Belasco, Robert S. Luce, Sam L. Pool
• Inventors: Mangold, Donald W., Petersen, Howard L., Fletcher, James C. Administrator of the National Aeronautics and Space (N/A), Cleveland, Garry J., Loh, George M., Luce, Robert S., Belasco, Norman, Lipanovich, Marko I., Pool, Sam L.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/354,406
• Time in Patent Office: 895 Days
• Field of Search: 128/2H,2.6B,2.6E,2.6R,2.1A,2.1R
• US Class Current: 600/483
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/301 providing electrical separation, e.g. by using isolating transformers or optocouplers
• CPC Class Codes: A61B 5/308 for electrocardiography [ECG]
• CPC Class Codes: Y10S 128/908 Patient protection from electric shock

Abstract

This invention relates to multi-channel, subject monitoring systems and especially to such medical monitoring systems allowing the monitored subject freedom of movement. Many types of sensors may be employed and differently arranged. The outputs of the sensors are suitably amplified and conditioned to provide the necessary voltage levels for the multiplexers in the analog-todigital (A/D) converters. The measured phenomena are displayed at a remote monitoring and control station. The entire system includes a bio-belt linked by optically coupled transmission and reception links to a data acquisition unit (DAU) having a central station function of controlling and displaying the output from the bio-belt.

Claims

1. A medical monitoring system for monitoring at least one physiological signal from a plurality of transducers mounted on the body of a subject being monitored, said system comprising a bio-unit, to be associated with the subject, and coupled with the transducers, a data acquisition unit, and a bidirectional coaxial cable having a signal bus and a command bus linking the bio-unit with the data acquisition unit;

said bio-unit comprising at least one signal-conditioning channel and means for controlling the output of the signal conditioning channel, a power pack for supplying power to the bio-unit, a signal conditioner for conditioning the analog signal generated by the transducer, calibration means including a standard signal for calibrating the signal conditioner, multiplexing means for sampling at selectively preselected rates for each channel the output of the signal conditioner and of the calibration means, and decoder means for driving the multiplexing means, for controlling the application of the output of the signal conditioning channel to the multiplexing means, and for controlling the application of the output of the calibration means to the multiplexing means;

an analog-to-digital converter for receiving the multiplexed analog data and converting it into digital data, means for applying the digital data to a signal bus line in said cable, means for receiving command data from a command bus line in said cable, optical couplers in said signal bus line and said command data bus to electrically isolate the subject from the data acquisition unit, synchronizing means for applying the command data to said decoder means in said signal conditioning channel, and decoding means for decoding the command data to control the operation of said analog-to-digital converter;

said data acquisition unit comprising;

a digital-to-analog converter receiving the digital data from the signal bus line and for reconverting the digital data into analog data, timing control logic means for controlling the digital-to-analog converter and for selectively generating said command data, and utilization means coupled to said digital-to-analog converter for monitoring the reconverted analog data.

2. A medical monitoring system for monitoring at least one physiological signal from a plurality of transducers mounted on the body of a subject being monitored, said system comprising a bio-unit, to be associated with the subject, a data acquisition unit, and a bidirectional coaxial cable having a signal bus line and command data bus line linking the bio-unit with the data acquisition unit;

said bio-unit comprising a plurality of transducers and a signal-conditioning channel for each transducer and means for selectively controlling the signal conditioning channels;

a power pack for supplying power to the bio-unit, each signal conditioning channel, comprising;

a signal conditioner for conditioning the analog signal generated by the transducer, calibration means for calibrating the signal conditioner with reference to a standard signal, multiplexing means for selectively sampling at preselected rates for each channel the output of individual signal conditioning channels and of the calibration means, decoder means for driving the multiplexing means, for controlling the application of the output of the selected signal conditioning channel to the multiplexing means, and for controlling the application of the output of the calibration means to the multiplexing means;

an analog-to-digital converter for receiving the multiplexed analog data from said channels and for converting it into digital data, means for applying the digital data to a signal bus line in said coaxial cable, means for receiving command data from a command bus line in said coaxial cable, optical couplers in said coaxial cable eLectrically isolating the subject from data acquisition unit, synchronizing means for applying the command data to said decoder means, and decoding means for decoding the command data to control the operation of said analog-to-digital converter;

said data acquisition unit comprising;

a plurality of digital-to-analog converters one for each channel for receiving the digital data signals from the signal bus line and reconverting the digital data into analog data, timing control logic means for controlling the digital-to-analog converters and for selectively generating said command data, and utilization means coupled to said digital-to-analog converters for monitoring the reconverted analog data.

3. A medical monitoring system for monitoring at least one physiological signal from a plurality of transducers mounted on the body of a subject being monitored, said system comprising a bio-unit, to be associated with the subject, a data acquisition unit, and a bidirectional coaxial cable having a signal bus line and command data bus line linking the bio-unit with the data acquisition unit;

said bio-unit comprising a plurality of signal-conditioning channels and means for selectively controlling the signal conditioning channels, each signal conditioning channel comprising;

a signal conditioner for conditioning the analog signal generated by the transducer, and multiplexing means for selectively sampling at preselected rates for each channel the output of the individual signal conditioner upon signal from the data acquisition unit;

an analog-to-digital converter for receiving the multiplexed analog data from said selected channel and for converting it into digital data, means for applying the digital data to a signal bus line in said cable, means for receiving command data from a command bus line in said cable; and

coupling means in said coaxial cable electrically isolating the bus unit from the data acquisition unit, said data acquisition unit comprising;

a plurality of digital-to-analog converters one for each channel for reconverting the digital data into analog data, timing control logic means for controlling the digital-toanalog converters and for selectively generating said command data, which activates the multiplexing means and determines selectivity of sample rate of individual signal conditioning channels, and utilization means coupled to said digital-to-analog converter for monitoring the reconverted analog data.

4. The system of claim 3 wherein each of said first and second couplers is an optical coupler.

5. The system of claim 4 wherein each channel of said signal conditioning channels further comprising:

a calibration means for calibrating the signal conditioner with reference to a standard signal, and decoder means for driving the multiplexing means, for controlling the application of the output of the signal conditioner to the multiplexing means, and for controlling the application of the output of the calibration means to the multiplexing means.

6. The system of claim 5 wherein said system further comprises:

synchronizing means for applying the command data to said decoding means in said signal conditioning channels, and decoding means for decoding the command data to control the operation of said analog-to-digital converters.