Spread spectrum telemetry of physiological signals

• US 5,617,871 A
• Filed: 12/01/1994
• Issued: 04/08/1997
• Est. Priority Date: 11/02/1993
• Status: Expired due to Term

• Current Assignee: Cardiac Science Operating Company (Cardica Incorporated)
• Original Assignee: Quinton Instrument Co. (Cardica Incorporated)
• Inventors: Burrows, Fremont W.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US08/347,750
• Time in Patent Office: 859 Days
• Field of Search: 128/630, 128/696, 128/903, 607/32, 607/60
• US Class Current: 600/300
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: Y10S 128/903 Radio telemetry
• CPC Class Codes: Y10S 128/904 Telephone telemetry

Abstract

A system for the transmission of physiological signals from a patient to a display analysis and/or recording device using a spread spectrum transmission technique to reduce interference with the detection of the transmitted physiological signal wherein multiple channels of the physiological signals are transmitted over a bandwidth of approximately 3 MHz.

Claims

1. A spread spectrum telemetry system for the acquisition of physiological signals from a patient and transmission of said signals to a data receiving device, said system comprising;

a first device for the acquisition of the desired physiological data from the patient and for processing a physiological signal consisting of a data stream corresponding thereto;

means for producing a data stream representative of a predetermined code sequence;

said first device further including a spread spectrum signal transmission device which combines said data stream representative of said physiological signal with said data stream representative of a predetermined code sequence to form a combined data transmission signal which is transmitted continuously as a spread spectrum signal from said first device over a wide frequency bandwidth;

a second device including a spread spectrum signal receiving device which receives said spread spectrum signal from said first device;

a demodulation processor associated with said second device which separates said data stream representative of said physiological signal from said data stream representative of a predetermined code sequence and converts said data streams into a serial data stream and a clock signal;

a physiological data receiving device associated with said second device for the receipt and utilization of said data stream representative of said physiological signal; and

a synchronization detector in said second device for searching said spread spectrum signal for framing words and said synchronization detector using said framing words to synchronize said spread spectrum signal and allow said data stream representative of said physiological signal to be separated therefrom.

2. The system of claim 1 wherein said spread spectrum signal transmitter transmits said spread spectrum signal from said first device to said second device in a radio frequency range of about 2400 to 2483 MHz.

3. The system of claim 1 wherein said spread spectrum signal transmitter transmits said spread spectrum signal from said first device to said second device in a radio frequency range of about 5700 to 5850 MHz.

4. The system of claim 1 wherein said first device transmits said spread spectrum signal to a plurality of said receiving devices and at least one of said plurality of receiving devices selects the proper spread spectrum signal transmission for receipt thereby by recognizing the a predetermined code sequence in said spread spectrum signal transmission.

5. The system of claim 1 wherein a plurality of physiological signals are transmitted via said spread spectrum signal from said first device to a plurality of said receiving devices.

6. The system of claim 1 wherein a plurality of said first devices transmit said spread spectrum signals to a single one of said receiving devices.

7. The system of claim 1 wherein said acquired physiological signals include signals representative of ECG waveforms therein and said receiving device provides a real time representation of the ECG waveforms of the patient.

8. A method for transmitting physiological signals acquired from a patient by a first device including a transmitter therein to a second device including a data receiving device therein, the method comprising;

acquiring physiological signals from a patient;

processing the acquired physiological signals of the patient to form a digital data stream representative of the physiological signals;

producing a predetermined code sequence;

combining the processed physiological signal with the predetermined code sequence to form a spread spectrum signal;

continuously transmitting the spread spectrum signal from the spread spectrum signal transmitter to the second device which includes a spread spectrum signal receiver associated therewith;

receiving the spread spectrum signal with the receiver of the second device;

separating the processed physiological signal from the predetermined code sequence;

receiving the processed physiological signal;

providing and utilizing the physiological signal for use by a physician with a physiological data receiving device; and

transmitting a plurality of physiological signals as part of the spread spectrum signal.

9. The method of claim 8 including the step of transmitting the spread spectrum signal to the receiver of the second device via a frequency hopping system from the first device.

10. The method of claim 8 including the step of transmitting the spread spectrum signal to the receiver of the second device via a pulsed FM modulation system from the first device.

11. The method of claim 8 further including the step of searching the received spread spectrum signal for framing words to determine the synchronization requirements of the spread spectrum signal and to allow the data stream representative of the physiological signal to be separated therefrom.

12. The method of claim 8 including the step of using multiple independent frequency channels for transmitting the spread spectrum signal to the second device.

13. The system of claim 12 including the step of interfacing the received spread spectrum signal synchronously and serially with the receiver of the second device.

14. A spread spectrum telemetry system for transmitting physiological signals acquired from a patient by a first device to a second device including a data receiving device, the system comprising;

means for acquiring physiological signals from a patient;

means for processing said acquired physiological signals of the patient to provide a data stream representative of the acquired physiological signal;

means for providing a predetermined code sequence;

means for combining the processed physiological signal with the predetermined code sequence to form a spread spectrum signal;

means for continuously transmitting said spread spectrum signal including a spread spectrum transmitter for transmitting said spread spectrum signal from said spread spectrum signal transmitter of said first device to a spread spectrum signal receiver of said second device;

means for receiving the spread spectrum signal including said spread spectrum signal receiver as part of said second device;

means for separating and processing said physiological signal from said predetermined code sequence; and

means for receiving said processed physiological signal and said means for receiving providing a representation of said physiological signal with a physiological data receiving device.

15. A spread spectrum telemetry system for the acquisition of physiological signals from a patient and transmission of said signals to a data receiving device, said system comprising;

a first device for the acquisition of the desired physiological data from the patient and for processing a physiological signal consisting of a data stream corresponding thereto;

an analog to digital converter to convert said physiological signal representative of said physiological signal into a digital data stream;

a filter to filter said digital data stream;

means for producing a data stream representative of a predetermined code sequence;

said first device further including a spread spectrum signal transmission device which combines said filtered digital data stream with said data stream representative of a predetermined code sequence to form a combined data transmission signal which is transmitted as a spread spectrum signal from said first device;

a second device including a spread spectrum signal receiving device which receives said spread spectrum signal from said first device;

a demodulation processor associated with said second device which separates said filtered digital data stream representative of said physiological signal from said data stream representative of said predetermined code sequence to convert said data streams into a serial data stream representative of said physiological signal; and

a physiological data receiving device associated with said second device for the receipt and utilization of said data stream representative of said physiological signal.

16. The system of claim 15 wherein said second device further includes a reformatting processor associated therewith and which converts a serial data stream having a data stream representative of said physiological signal therein to an analog data signal for analysis by said data receiving device.

17. A method for transmitting physiological signals acquired from a patient by a first device including a transmitter therein to a second device including a data receiving device therein, the method comprising;

acquiring physiological signals from a patient;

converting the acquired physiological signals of the patient from an analog signal to a digital data stream with an analog to digital converter to form a digital data stream representative of the physiological signals;

filtering the digital data stream to form a filtered digital data stream;

producing a predetermined code sequence;

combining the filtered digital data stream with the predetermined code sequence to form a spread spectrum signal;

transmitting the spread spectrum signal from the spread spectrum signal transmitter to the second device which includes a spread spectrum signal receiver associated therewith;

receiving the spread spectrum signal with the receiver of the second device;

separating the filtered digital data stream representative of the processed physiological signals from the predetermined code sequence;

receiving and processing the filtered digital data stream to form a processed physiological signal; and

providing and utilizing the processed physiological signal for use by a physician with a physiological data receiving device.

18. The method of claim 17 including the step of converting the physiological signal to a digital data stream by an A to D converter in the first device and receiving a reformatted serial data stream with a data reformatting processor in the second device and performing analysis of the processed physiological signal in the second device.

19. A spread spectrum telemetry system for the acquisition, of physiological signals from a patient and transmission of said signals to a data receiving device, said system comprising;

a first device for the acquisition of the desired physiological data from the patient and for processing a physiological signal consisting of a data stream corresponding thereto;

an analog to digital converter to convert said physiological signal representative of said physiological signal into a digital data stream;

means for producing a data stream representative of a predetermined code sequence;

said first device further including a spread spectrum signal transmission device which combines said digital data stream with said data stream representative of a predetermined code sequence to form a combined data transmission signal which is transmitted as a spread spectrum signal from said first device;

a second device including a spread spectrum signal receiving device which receives said spread spectrum signal from said first device;

a demodulation processor associated with said second device which receives said combined data transmission signal and processes said combined data transmission signal to create a processed data stream representative of said physiological signal; and

a physiological data receiving device associated with said second device for the receipt and analysis of said processed data stream representative of said physiological signal.

20. The system of claim 19 wherein said first device includes a filter means to filter said digital data stream prior to transmission thereof and said second device further includes a reformatting processor associated therewith and which converts a serial data stream receiving from said demodulation processor having a representation of said physiological signal therein to an analog data signal for analysis by said data receiving device.

21. A method for transmitting physiological signals acquired from a patient by a first device including a transmitter therein to a second device including a data receiving device therein, the method comprising;

acquiring physiological signals from a patient;

converting the acquired physiological signals of the patient from an analog signal to a digital data stream with an analog to digital converter to form a digital data stream representative of the physiological signals;

producing a predetermined code sequence;

combining the digital data stream with the predetermined code sequence to form a spread spectrum signal;

transmitting the spread spectrum signal from the spread spectrum signal transmitter to the second device which includes a spread spectrum signal receiver associated therewith;

receiving the spread spectrum signal with the receiver of the second device;

separating the received spread spectrum signal into a processed physiological signal and a predetermined code sequence;

receiving the processed physiological signal; and

analyzing and providing the processed physiological signal for use by a physician with a physiological data receiving and analysis device.

22. The method of claim 21 including the step of converting the physiological signal to a digital data stream by an A to D converter in the first device and receipt of a reformatted serial data stream from a data reformatting processor in the second device and performing analysis of the reformatted serial data stream received from the data reformatting processor in the second device.

23. A spread spectrum telemetry system for transmitting physiological signals acquired from a patient by a first device to a second device including a data receiving device, the system comprising;

means for acquiring physiological signals from a patient;

means for converting said acquired physiological signals of the patient from an analog signal to a digital data stream to provide a digital data stream representative of the acquired physiological signal;

means for filtering said digital data stream;

means for creating a predetermined code sequence;

means for combining the filtered digital data stream with said predetermined code sequence to form a spread spectrum signal;

means for transmitting said spread spectrum signal including a spread spectrum transmitter for transmitting said spread spectrum signal from said spread spectrum signal transmitter of said first device to a spread spectrum signal receiver of said second device;

means for receiving the spread spectrum signal including said spread spectrum signal receiver as part of said second device;

means for separating and processing said physiological signal from said predetermined code sequence; and

means for receiving said processed physiological signal and said means for receiving providing a representation of said physiological signal with a physiological data receiving device.

24. A spread spectrum telemetry system for transmitting physiological signals acquired from a patient by a first device to a second device including a data receiving device, the system comprising;

means for acquiring physiological signals from a patient;

means for converting said acquired physiological signals of the patient from an analog signal to a digital data stream provide a digital data stream representative of the acquired physiological signal;

means for creating a predetermined code sequence;

means for combining said digital data stream with said predetermined code sequence to form a spread spectrum signal;

means for transmitting said spread spectrum signal including a spread spectrum transmitter for transmitting said spread spectrum signal from said spread spectrum signal transmitter of said first device to a spread spectrum signal receiver of said second device;

means for receiving the spread spectrum signal including said spread spectrum signal receiver as part of said second device;

means for separating and processing said physiological signal from said predetermined code sequence;

means for receiving said processed physiological signal including means for receiving and providing a representation of said physiological signal with a physiological data receiving device;

means for performing an analysis of said representation of said physiological signal for use by a physician.