Method of and apparatus for detecting vital functions of living bodies

• US 6,122,537 A
• Filed: 01/12/1997
• Issued: 09/19/2000
• Est. Priority Date: 01/20/1994
• Status: Expired due to Fees

• Current Assignee: Selectornic Gesellschaft Fur Sicherheitstechnik und Sonderelektronik mbH
• Original Assignee: Selectornic Gesellschaft Fur Sicherheitstechnik und Sonderelektronik mbH
• Inventors: Schmidt, Gerd Juergen
• Primary Examiner(s): Casler, Brian L.
• Application Number:
  US08/676,321
• Time in Patent Office: 1,346 Days
• Field of Search: 600/407, 600/300, 600/301, 600/481, 600/529, 600/483, 600/508, 600/484, 600/534
• US Class Current: 600/407
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A63B 2208/12 specially adapted for children
• CPC Class Codes: A63B 29/021 Means for indicating the location of accidentally buried, e.g. snow-buried, persons
• CPC Class Codes: C08L 31/00 Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid or of a haloformic acid of hydrolysed polymers C08L29/00; Compositions of derivatives of such polymers
• CPC Class Codes: G01S 13/56 for presence detection presence detection using near field arrangements G01V3/00, e.g. G01V3/08, G01V3/12; burglar, theft or intruder alarms with electrical actuation G08B13/22 - G08B13/26
• CPC Class Codes: G01S 7/415 Identification of targets based on measurements of movement associated with the target
• CPC Class Codes: G02B 1/041 Lenses

Abstract

An apparatus for detecting vital functions of living bodies by means of electromagnetic signals includes a receiving device for electromagnetic signals. The receiving device for electromagnetic signals includes a device for obtaining frequency components that are characteristic of living bodies, out of received electromagnetic signals. The receiving device includes a direct demodulator that has a non-linear current/voltage characteristic that is frequency-selective for demodulation of frequency components that are characteristic of living bodies.

Claims

1. Apparatus for detecting vital functions of living bodies by detecting electromagnetic signals comprising a receiving device for receiving electromagnetic signals from living bodies, wherein the receiving device (3) for receiving electromagnetic signals includes a device for obtaining frequency components that are characteristic of the living bodies, out of the received electromagnetic signals, wherein the receiving device (3) includes a direct demodulator (5) that has a non-linear current/voltage characteristic that is frequency-selective for demodulation of frequency components that are characteristic of the living bodies.

2. Apparatus as set forth in claim 1 characterized in that the direct demodulator demodulates frequency components which are characteristic of vital functions of living bodies directly out of the received electromagnetic signals.

3. Apparatus as set forth in claim 2 characterized in that the direct demodulator (3) includes one of a diode, a bipolar and a field effect transistor as the frequency-selective element.

4. Apparatus as set forth in claim 1 characterized in that the receiving device (3) includes a frequency conversion device (6) connected ahead of the demodulator (5) in a direction in which the electromagnetic signals are received.

5. Apparatus as set forth in claim 1 characterized in that the apparatus includes a transmission device (1) transmitting of an electromagnetic carrier signal at a fixed frequency.

6. Apparatus as set forth in claim 5 characterized in that the carrier signal is in a frequency range of approximately one MHz to approximately one THz.

7. Apparatus as set forth in claim 1 characterized in that the device for obtaining frequency components which are characteristic of the living bodies includes a filter device (7), a sampling device, an A/D converter (9) and a computing device (10) for spectral analysis.

8. Apparatus as set forth in claim 7 characterised in that the filter device (7) includes at least one analog sampling filter.

9. Apparatus as set forth in claim 8 characterised in that the sampling filter limits the band width of the electromagnetic signal towards high frequencies prior to the sampling operation and prior to the A/D conversion operation.

10. Apparatus as set forth in claim 1 characterized in that the apparatus further includes a transmission antenna (2) for transmitting an electromagnetic carrier signal, and the receiving device comprises a receiving antenna (4) wherein the transmission and receiving antenna are held in a common housing (14) for pivoting and nutating movement with a releasably fixable holder (19).

11. Apparatus as set forth in claim 1 characterized in that the apparatus further includes a transmission antenna (2) for transmitting an electromagnetic carrier signal and the receiving device comprises a receiving antenna (4) wherein the transmission and receiving antenna are mounted in a common housing (14) which is fixed to a ceiling (24) by way of a holder (23) which is adjustable in respect of height.

12. Use of an apparatus as set forth in claim 1 further including positioning means for positioning the apparatus to allow for contact-free monitoring of the vital functions of intensive care patients.

13. Use of an apparatus as set forth in claim 1 further including positioning means for positioning the apparatus to allow for monitoring one of small children and apnoea patients for at least one of cardiac and respiratory arrest.

14. Use of an apparatus as set forth in claim 1 further including positioning means for positioning the apparatus to allow for monitoring the state of inmates in places of detention.

15. Use of an apparatus as set forth in claim 1 further including positioning means for positioning the apparatus to allow for at least one of monitoring and safeguarding at least one of rooms, buildings and open land surrounding same.

16. A method for detecting vital functions of living bodies by detecting electromagnetic signals comprising receiving electromagnetic signals from living bodies and obtaining frequency components which are characteristic of the living bodies from the received electromagnetic signals by directly demodulating the received electromagnetic signals by a direct demodulator having a non-linear current/voltage characteristic that is frequency-selective for demodulation of frequency components that are characteristic of the living bodies.

17. The method as set forth in claim 16 further characterized by converting the received electromagnetic signals to an intermediate frequency between high and low frequencies.

18. The method as set forth in claim 16 further characterized by limiting the received electromagnetic signals with an analog device towards high and low frequencies.

19. The method as set forth in claim 18 further characterized by transforming the digital signals from a time region into a frequency region and then evaluating and representing the digital signals as output signals.

20. The method as set forth in claim 19 further characterized by analyzing the transformed signals in a frequency range of from about 0.01 Hz through about 10 Hz for frequency components of at least one of cardiac and respiratory activity, which are characteristic of vital functions of living bodies.

21. The method as set forth in claim 20 further characterized by analyzing the transformed signals in a frequency range between about 0.02 Hz and about 3 Hz.

22. The method as set forth in claim 16 further characterized by filtering, sampling, and converting the received electromagnetic signals into digital signals.

23. The method according to claim 22 further characterized by folding the digital signals with a window function in a time region and with an inverse transfer function of a receiving device.

24. The method as set forth in claim 16 wherein the step of obtaining frequency components which are characteristic of the living bodies further includes contact-free monitoring of the vital functions of intensive care patients.

25. The method as set forth in claim 16 wherein the step of obtaining frequency components which are characteristic of the living bodies further includes monitoring at least one of small children and apnea patients for at least one of cardiac and respiratory arrest.

26. The method as set forth in claim 16 wherein the step of obtaining frequency components which are characteristic of the living bodies further includes monitoring the state of inmates in places of detention.

27. The method as set forth in claim 16 wherein the step of obtaining frequency components which are characteristic of the living bodies further includes at least one of monitoring and safeguarding at least one of rooms, buildings, and open land surrounding same.