Apparatus for monitoring electrical signals, either artificial and/or natural in a living body, via a communication link

• US 3,872,252 A
• Filed: 03/07/1973
• Issued: 03/18/1975
• Est. Priority Date: 03/07/1973
• Status: Expired due to Term

• Current Assignee: Franklin Leonard Malchman, Robert William Johnson, William J. Raddi
• Original Assignee: Franklin Leonard Malchman, Robert William Johnson, William J. Raddi
• Inventors: Johnson, Robert William, Raddi, William J., Malchman, Franklin Leonard
• Primary Examiner(s): Stewart, David L.
• Application Number:
  US05/337,261
• Time in Patent Office: 741 Days
• Field of Search: 128/2.1A,2.6B,2.6R,2.6F,419P 179/2A,2DP,15BM
• US Class Current: 607/27
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/7217 of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker
• CPC Class Codes: A61N 1/3702 Physiological parameters A61N1/365 takes precedence; evoked response A61N1/371
• CPC Class Codes: Y10S 128/904 Telephone telemetry

Abstract

A monitor apparatus for simultaneously monitoring via a telephone communication link electrocardiographic signals of a patient produced as a result of the heart function of the patient, and electrical artifact signals produced as a result of the electrical output of a heart pacer artificially stimulating the heart of the patient. The monitor apparatus includes a transducer adapted to sense both the electrocardiographic signals and the electrical artifact signals of a patient and to process the sensed signals to transmittable signals for transmission over the telephone communication link. The monitor apparatus also includes a receiver adapted to receive the signals transmitted over the telephone communication link and to process the received signals for providing a visual display to an observer of information indicative of the repetition rate of the electrical artifact signals and a recorded read-out indicative of the electrocardiographic signals along with the artifact signals and the time occurrence relationship of the artifact signals with respect to the electrocardiographic signals.

Claims

1. A transducer for monitoring electrical artifact signals of a living body resulting from artificial stimulation of a body part comprising:

a. sensing means connectable to the body for sensing electrical artifact signals in the body;

b. generating means for generating an electrical carrier signal;

c. output means operatively connected to the generating means and including means for producing an output signal in correspondence to the electrical carrier signal when the electrical carrier signal is coupled to the output means;

d. control means operatively connected between the generating means and the output means for normally permitting coupling to the output means of the electrical carrier signal and for modulating the the amplitude of the electrical carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means; and

e. channel means operatively connected to the sensing means and to the control means and including control signal producing means responsive to each sensed electrical artifact signal for providing a control signal for effecting operation of the control means to modulate the amplitude of the electrical carrier signal 100 percent.

2. A transducer for monitoring electrical signals of a living body resulting from both natural and artificial stimulation of a body part comprising:

a. sensing means connectable to the body for sensing electrical stimulation signals in the body;

b. first channel means operatively connected to the sensing means and including generating means for generating an electrical carrier signal, and modulation means for frequency modulating the electrical carrier signal in response to sensed natural stimulation signals to provide a frequency modulated carrier signal;

c. output means operatively connected to the first channel means for producing an output signal in correspondence to the frequency modulated carrier signal when the frequency modulated carrier signal is coupled to the output means;

d. control means operatively connected between the first channel means and the output means for normally permitting coupling to the output means of the frequency modulated carrier signal and for modulating the amplitude of the frequency modulated carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means; and

e. second channel means operatively connected to the sensing means and the control means and including control signal producing means responsive to each sensed artificial stimulation signal for providing a control signal for effecting operation of the control means to modulate the amplitude of the frequency modulated carrier signal 100 percent.

3. A transducer for monitoring electrical signals of a patient resulting from both naturally occurring electrocardiographic signals and artificial electrical stimulation signals stimulating the heart of the patient comprising:

a. sensing means connectable to the body for sensing naturally occurring electrocardiographic signals and for sensing artificial electrical stimulation signals in the body;

b. first channel means operatively connected to the sensing means, the first channel means comprising;

i. first means for providing an electrical carrier signal; and

ii. second means operatively connected to the first means and to the sensing means for frequency modulating the electrical carrier signal in response to the sensed naturally occurring electrocardiographic signals to thereby provide a frequency modulated carrier sigNal;

c. output means operatively connected to the first means for producing an output signal in correspondence to the frequency modulated carrier signal when the frequency modulated carrier signal is coupled to the output means;

d. control means operatively connected between the first means and the output means for normally permitting coupling to the output means of the frequency modulated carrier signal and for modulating the amplitude of the modulated carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means;

e. second channel means operatively connected to the sensing means and the control means, the second channel means comprising;

i. detector means operatively connected to the sensing means for detecting the occurrence of each artificial stimulation signal and for providing an output signal in response to the detection of an artificial stimulation signal; and

ii. control signal producing means operatively connected to the detector means and to the control means for providing a control signal to the control means in response to an output signal from the detector means which control signal effects operation of the control means to modulate the amplitude of the frequency modulated carrier signal 100 percent.

4. A transducer for monitoring both electrocardiographic signals of a patient and electrical artifact signals of a patient produced as the result of the electrical output of a heart pacer artificial stimulating the heart of the patient, comprising:

a. sensing means connectable to a patient to provide electrocardiographic signals in response to the patient'"'"''"'"'s heart function and to provide electrical artifact signals in response to the electrical output of a heart pacer artificially stimulating the patient'"'"''"'"'s heart;

b. first channel means operatively connected to the sensing means, the first channel means comprising;

i. first means to provide an electrical carrier signal, and ii. second means operatively connected to the first means and to the sensing means to frequency modulate the electrical carrier signal in response to sensed electrocardiographic signals to provide a frequency modulated electrical carrier signal, c. output means operatively connected to first means for providing an audible output signal in correspondence to the frequency modulated electrical carrier signal when the frequency modulated electrical carrier signal is coupled to the output means;

d. control means operatively connected between the first channel means and the output means and being operative to normally couple the frequency modulated electrical carrier signal to the output means and for modulating the amplitude of the frequency modulated electrical carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means; and

e. second channel means operatively connected to the sensing means and to the control means, the second channel means comprising;

i. first means operatively connected to the sensing means for providing an electrical output signal in response to each electrical artifact signal, and ii. control signal producing means operatively connected to the first means of the second channel means and to the control means to provide a control signal to the control means in response to each electrical output signal of the first means of the second channel means which control signal when applied to the control means effects operation of the control means to modulate the amplitude of the frequency modulated electrical carrier signal 100 percent.

5. A transducer for simultaneously monitoring both electrocardiographic signals of a patient and electrical artifact signals of a patient produced as the result of the electrical output of a heart pacer artificial stimulating the heart of the patient, comprising:

a. sensing means connectable to a patient to proviDe electrocardiographic signals in response to the patient'"'"''"'"'s heart function and to provide electrical artifact signals in response to the electrical output of a heart pacer artificially stimulating the patient'"'"''"'"'s heart;

b. first channel means operatively connected to the sensing means, the first channel means comprising;

i. first means to provide an electrical carrier signal of predetermined frequency; and

ii. second means operatively connected to the first means and to the sensing means to frequency modulate the electrical carrier signal with the voltage amplitude of the electrocardiographic signals to provide a frequency modulated electrical carrier signal;

c. output means operatively connected to the first means for providing an audible output signal in correspondence to the frequency modulated electrical carrier signal when the frequency modulated electrical carrier signal is coupled to the output means;

d. control means operatively connected between the first channel means and the output means and being operative to normally couple the frequency modulated electrical carrier signal to the output means and for modulating the amplitude of the frequency modulated electrical carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means; and

e. second channel means operatively connected to the sensing means and to the control means, the second channel means comprising;

i. detector means operatively connected to the sensing means for providing an electrical output signal in response to the detection of each electrical artifact signal, and ii. control signal producing means operatively connected to the detector means and to the control means, and being coupled to the electrical output signals of the detector means to provide a control signal for a predetermined time interval to the control means in response to each electrical output signal of the detector means which control signal when applied to the control means effects operation of the control means to modulate the amplitude of the frequency modulated electrical carrier 100 percent for the duration of the control signal.

6. A transducer as defined in claim 5 wherein the first channel means further comprises means for attenuating electrical artifact signals thereby effectively preventing electrical artifact signals from passing through the first channel means.

7. A transducer as defined in claim 5 wherein the detector means includes means for attenuating electrocardiographic signals thereby effectively preventing electrocardiographic signals from passing through the second channel means.

8. A receiver apparatus for receiving a carrier signal which at times is amplitude modulated to provide information indicative of the occurrence of an artificial stimulation signal in a living body, the receiver apparatus comprising:

channel mens including measuring means for measuring the time interval between successive pairs of amplitude modulations of the carrier signal, the measured time interval between each successive pair of amplitude modulations of the carrier signal being indicative of the time interval between each successive pair of artificial stimulation signals, the channel means further including;

i. first means for providing a continuous pulsating signal at a preselected frequency in response to a carrier signal being received by the receiver and ceasing the pulsations upon the occurrence of an amplitude modulation of the carrier signal being received by the receiver;

ii. second means operatively connected to the first means for providing an output signal a predetermined time interval after the cessation of pulsations from the first means;

the measuring means measuring the time interval between successive pairs of output signals of the second means.

9. A receiver apparatus as defined in claim 8 including conversion means operatively connected to the measuring meanS for converting the time interval measurements of the measuring means to the rate of the occurrence of the artificial stimulation signals.

10. A receiver apparatus for receiving a transmitted carrier signal which at times is 100 percent amplitude modulated to provide information indicative of the occurrence of an artificial stimulation signal in a living body and which carrier signal is also frequency modulated to contain information indicative of naturally occurring stimulation signals in a living body, the receiver apparatus comprising:

a. first channel means including means for measuring the time interval between successive pairs of 100 percent amplitude modulations of the carrier signal; and

b. second channel means including means for demodulating the frequency modulated carrier signal to provide a demodulated signal, and means for recording the demodulated signal.

11. A receiver apparatus for simultaneously receiving a frequency modulated carrier signal which results from a carrier signal being frequency modulated by the electrocardiographic signals of a patient and which frequency modulated carrier signal is at times amplitude modulated to provide information indicative of the occurrence of an artificial stimulation signal produced in the patient as the result of the electrical output of a heart pacer artificially stimulating the heart of the patient;

the receiver apparatus comprising;

a. first channel means for measuring the time interval between successive pairs of amplitude modulations of the frequency modulated carrier signal, the first channel means comprising;

i. first means for providing a continuous pulsating signal at a preselected frequency in response to the frequency modulated carrier signal being received by the receiver and ceasing the pulsations upon the occurrence of an amplitude modulation of the frequency modulated carrier signal being received by the receiver;

ii. second means operatively connected to the first means for providing an output signal a predetermined time interval after the cessation of pulsations from the first means; and

iii. third means for measuring the time interval between successive pairs of output signals of the second means; and

b. second channel means for demodulating the frequency modulated carrier signal to provide a demodulated signal corresponding to the electrocardiographic signal of the patient and for presenting a visual read-out on the demodulated signal, the second channel means comprising;

i. first means for demodulating the modulated carrier signal and for providing a demodulated signal comprising a varying output voltage corresponding to the instantaneous voltage amplitude of the electrocardiographic signal which modulated the carrier signal, and, ii. second means operatively connected to the first means of the second channel means for providing a visual read-out corresponding to the output voltage of the first means of the second channel means.

12. A monitor apparatus for the monitoring via a telephone communication link electrocardiographic signals of a patient produced as a result of the heart function of the patient, and electrical artifact signals produced as the result of the electrical output of a heart pacer artificially stimulating the heart of the patient, the monitor apparatus comprising:

A. a transducer means, the transducer means comprising;

a. pick-up means connectable to a patient to provide electrocardiographic signals in response to the patient'"'"''"'"'s heart function and to provide electrical artifact signals in response to the electrical output of a heart pacer artificially stimulating the patient'"'"''"'"'s heart;

b. first channel means operatively connected to the pick-up means and including means for generating an electrical carrier signal, and means for frequency modulating the electrical carrier signal in response to sensed electrocardiographic signals to provide frequency modulated electrical carrier signal;

C. output means operatively connected to the first channel means to produce an audible output signal for transmission over the telephone communication link in correspondence to the frequency modulated electrical carrier signal when the frequency modulated electrical carrier signal is coupled to the output means;

d. control means operatively connected between the first channel means and to the output means for noramlly permitting coupling to the output means of the frequency modulated electrical carrier signal and for modulating the amplitude of the frequency modulated electrical carrier signal 100 percent in response to a control signal thereby cutting off the electrical carrier signal from the output means; and

e. second channel means operatively connected to the pick-up means and the control means and including control signal producing means responsive to each sensed electrical artifact signal for providing a control signal for effecting operation of the control means to modulate the amplitude of the frequency modulated electrical carrier signal 100 percent such that an audible signal transmitted over the telephone communication link is 100 percent amplitude modulated; and

B. receiver apparatus for receiving audible signals transmitted over the communication link, the receiver apparatus comprising;

a. first channel means including measuring means for measuring the time interval between successive pairs of 100 percent amplitude modulations of the frequency modulated electrical carrier signal; and

b. second channel means including means for demodulating the frequency modulated carrier signal to provide a demodulated signal comprising a varying output voltage corresponding to the electrocardiographic signals of the patient, and means for recording the varying output voltage.

13. A monitor apparatus as defined in claim 12 wherein the first channel means of the receiver apparatus includes conversion means operatively connected to the measuring means for converting the time interval measurements of the measuring means to the rate of occurrence of the amplitude modulations of the modulated electrical carrier signal.

14. A monitor apparatus for the simultaneous monitoring via a telephone communication link electrocardiographic signals of a patient produced as a result of the heart function of the patient, and electrical artifact signals produced as the result of the electrical output of a heart pacer artificially stimulating the heart of the patient, the monitor apparatus comprising:

A. a transducer means, the transducer means comprising;

a. pick-up means connectable to a patient to provide electrocardiographic signals in response to the patient'"'"''"'"'s heart function and to provide electrical artifact signals in response to the electrical output of a heart pacer artificially stimulating the patient'"'"''"'"'s heart;

b. first channel means operatively connected to the pick-up means and including means for generating an electrical carrier signal, and means for frequency modulating the electrical carrier signal with the voltage amplitude of the electrocardiographic signals to provide a frequency modulated electrical carrier signal;

c. output means operatively connected to the first channel means to produce an audible output signal for transmission over the telephone communication link in correspondence to the frequency modulated electrical carrier signal when the frequency modulated electrical carrier signal is coupled to the output means;

d. control means operatively connected between the first channel means and the output means and being operative for normally coupling the frequency modulated electrical carrier signal to the output means and thus permitting passage to the output means of the frequency modulated electrical carrier signal and for preventing such passage in response to a control signal;

e. second channel means operatively connected to the pick-up means and the control means and including fIrst means responsive to each sensed electrical artifact signal for providing an electrical output signal in response to each electrical artifact signal, and control signal producing means operatively connected to the first means and to the control means to provide a control signal to the control means in response to each electrical output signal of the first means which control signal effects the operation of the control means and thereby prevents the audible output signal from being transmitted over the telephone communication link thereby providing a 100 percent interruption in the transmission of the audible output signal over the communication link upon the occurrence of each control signal; and

B. receiver apparatus for receiving audible output signals transmitted over the telephone communication link, the receiver apparatus comprising;

a. first channel means including means responsive to 100 percent interruptions of the transmitted audible output signal, and means for measuring the time interval between successive pairs of 100 percent interruptions of the transmitted audible output signal; and

b. second channel means including means for demodulating the transmitted audible output signal to provide a demodulated signal corresponding to the electrocardiographic signal of the patient, and means for recording the demodulated signal.

15. A monitor apparatus as defined in claim 14 wherein the receiver means further includes:

a patient alert signal generating means for providing an audible signal of a predetermined first frequency which when coupled via the communication link to the transducer means alerts the patient to a preselected set of operating instructions; and

wherein the transducer means further includes;

means responsive to the transmitted audible signal of predetermined first frequency for providing an alerting signal to the patient.

16. A monitor apparatus as defined in claim 14 wherein the receiver means further includes:

calibration means for generating an audible signal of a predetermined second frequency which when coupled via the telephone communication link to the transducer means causes the transducer means to generate a reference voltage; and

wherein the transducer means further includes;

means for generating a reference voltage which when coupled to the first channel means of the transducer means effects operation of the first channel means to frequency modulate the electrical carrier with the amplitude of the reference voltage to provide a second modulated carrier signal which second modulated carrier signal is coupled to the output means to produce a second audible output signal which second audible signal is transmitted via the communication link to the receiver means and is coupled to the receiver apparatus, and wherein the second channel means of the receiver apparatus demodulates the transmitted second audible output signal to provide a demodulated signal comprising a voltage corresponding to the reference voltage thereby providing an indication of the absolute voltage amplitude of the elctrocardiographic signal recorded.