System for wireless transmission of medical data

• US 5,458,122 A
• Filed: 09/03/1993
• Issued: 10/17/1995
• Est. Priority Date: 09/04/1992
• Status: Expired due to Fees

• Current Assignee: Thomson - Csf
• Original Assignee: Thomson-CSF (Thales SA)
• Inventors: Hethuin, Serge
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Getzow, Scott M.
• Application Number:
  US08/115,600
• Time in Patent Office: 774 Days
• Field of Search: 128/696, 128/903, 128/902, 128/901, 128/904
• US Class Current: 600/509
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: Y10S 128/901 Suppression of noise in electric signal
• CPC Class Codes: Y10S 128/903 Radio telemetry

Abstract

The system for wireless transmission of medical data comprises a piece of transmission equipment carried by the patient which comprises a unit for differential amplification and band filtering, a unit for rejection of interference noises, particularly the sector and its harmonics, existing in the band of the useful signal, an amplification circuit with automatic gain control and a modulator receiving a carrier frequency, for example microwave at 2.45 GHz and the useful signal, in analog or after a digital conversion and optional processings. The system also comprises a suitable receiving station. The carrier frequency can be either generated in the transmission equipment, or in the receiving station which then transmits the nonmodulated carrier for the transmitters that are associated with it.

Claims

1. A system for transmitting medical data, comprising:

at least two electrodes to be placed on a body of a patient for generating an electrical signal;

a first unit for receiving the electrical signal from the at least two electrodes and for differential amplification and band-pass filtering of the electrical signal to reject a common mode;

a second unit for receiving the electrical signal differentially amplified and band-pass filtered from the first unit and for selectively rejecting a frequency of a sector and harmonics of the sector of the electrical signal, to generate an electrical transmission signal; and

a modulator for receiving the electrical transmission signal from the second unit and for modulating the electrical transmission signal by a transmission frequency carrier; and

an antenna for transmitting the modulated electrical transmission signal.

2. The system according to claim 1, wherein the modulator is a phase or frequency analog modulator, and the system further comprises an amplification circuit with automatic gain control located between the second unit and the modulator, and the modulator modulates the electrical transmission signal by the transmission frequency carrier in baseband.

3. The system according to claim 2, further comprising:

a channel coding circuit connected between the second unit and the modulator; and

a code generator connected to the channel coding circuit and which generates a code associated with a communication channel, to code the electrical transmission signal before transmission to the modulator.

4. The system according to claim 1, wherein the modulator is a digital modulator, and the system further comprises a chain for conversion and for digital processing of the electrical transmission signal in baseband to generate a digital electrical transmission signal, the modulator modulating the digital electrical transmission signal by the transmission frequency carrier.

5. The system according to claim 4, wherein the chain for conversion and for digital processing comprises, in series, a flow compression circuit, an error correcting coding circuit, and a circuit for formatting data to be transmitted.

6. The system according to claim 5, further comprising:

a channel coding circuit connected between the second unit and the modulator; and

a code generator connected to the channel coding circuit for generating a code associated with a communication, to code the electrical transmission signal before transmission to the modulator.

7. The system according to claim 6, wherein the code generator uses orthogonal pseudorandom codes of the GOLD or KASAMI type to define a number N of channels that can be separated using the same transmission frequency carrier.

8. The system according to claim 5, wherein the transmission frequency carrier is generated by a carrier frequency generator.

9. The system according to claim 1, further comprising a receiving station comprising a demodulator and a chain for processing the demodulated signal for the restoration of the electrical transmission signal.

10. The system according to claim 9, further comprising a channel coder connected between the second unit and the modulator and including an automatic gain control;

and wherein the chain for processing of the demodulated signal comprises an operator connected to an output of the demodulator and to an output of a channel code generator.

11. A system for transmitting medical data, comprising:

at least two electrodes to be placed on a body of a patient for generating an electrical signal;

a first unit for receiving the electrical signal from the at least two electrodes and for differential amplification and band-pass filtering of the electrical signal to reject a common mode;

a second unit for receiving the electrical signal differentially amplified and band-pass filtered from the first unit and for selectively rejecting a frequency of a sector and harmonics of the sector of the electrical signal, to generate an electrical transmission signal;

a chain for conversion and for digital processing of the electrical transmission signal in baseband to generate a digital electrical transmission signal, wherein the chain for conversion and for digital processing comprises, in series, a flow compression circuit, an error correcting coding circuit, and a circuit for formatting data to be transmitted;

a digital modulator for receiving the electrical transmission signal from the chain for conversion and for digital processing and for modulating the electrical transmission signal by a transmission frequency carrier; and

an antenna for transmitting the modulated electrical transmission signal.

12. The system according to claim 11, further comprising:

a channel coding circuit connected between the second unit and the modulator; and

a code generator connected to the channel coding circuit for generating a code associated with a communication, to code the electrical transmission signal before transmission to the modulator.

13. The system according to claim 12, wherein the code generator uses orthogonal pseudorandom codes of the GOLD or KASAMI type to define a number N of channels that can be separated using the same transmission frequency carrier.

14. The system according to claim 11, further comprising a receiving station comprising a demodulator and a chain for processing the demodulated signal for the restoration of the electrical transmission signal.

15. The system according to claim 14, further comprising a channel coder connected between the second unit and the modulator and including an automatic gain control;

and wherein the chain for processing of the demodulated signal comprises an operator connected to an output of the demodulator and to an output of a channel code generator.

16. The system according to claim 11, wherein the transmission frequency carrier is generated by a carrier frequency generator.