NON-CONTACT APPARATUS FOR MONITORING CARDIOPULMONARY ACTIVITY SIGNALS AND METHOD FOR THE SAME

• US 20080146944A1
• Filed: 12/12/2007
• Published: 06/19/2008
• Est. Priority Date: 12/13/2006
• Status: Active Grant

• Current Assignee: Industrial Technology Research Institute
• Original Assignee: Industrial Technology Research Institute
• Inventors: Peng, Jia Hung, Kuo, Su Chen, Tao, Teh Ho, Hu, Shih Jen
• Granted Patent: US 8,545,413 B2
• Time in Patent Office: Days
• US Class Current: 600/481
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00

Abstract

A non-contact apparatus for monitoring cardiopulmonary activity signals comprises a pulse-series generator configured to generate a series of probing pulses and a series of reference pulses, a transmitting antenna configured to emit the probing pulses to a chest portion and a series of scattered pulses generated from the probing pulses by the scattering of the chest portion, a receiving antenna configured to receive the scattered pulses, a mixer including a first input port configured to receive the reference pulses and a second input port electrically connected to the receiving antenna and a signal-processing module configured to generate cardiopulmonary activity signals after the scattered pulses and the reference pulses are processed by the mixer.

Claims

1. A non-contact apparatus for monitoring cardiopulmonary activity signals, comprising:

a pulse-series generator configured to generate a series of probing pulses and a series of reference pulses;

a transmitting antenna configured to transmit the probing pulses to a chest portion, wherein the chest portion scatters the probing pulses to generate a series of scattered pulses;

a receiving antenna configured to receive the scattered pulses;

a mixer including a first input port configured to receive the reference pulses and a second input port electrically connected to the receiving antenna to receive the scattered pulses;

a signal-processing module configured to generate the cardiopulmonary activity signals after the scattered pulses and the reference pulses are processed by the mixer.

2. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 1, wherein the pulse-series generator includes:

a pulse generator configured to generate a series of high-frequency sinusoidal pulses; and

a splitter coupled to the pulse generator and configured to generate the probing pulses and the reference pulses from the high-frequency sinusoidal pulses.

3. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 2, wherein the pulse generator includes:

a sinusoidal-signal generator configured to generate a continuous sinusoidal signal;

a switching-signal generator configured to generate a switching signal; and

a switching device configured to turn on according to the switching signal such that the continuous sinusoidal signal can pass through the switching device to form the high-frequency sinusoidal pulses.

4. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 3, wherein the switching-signal generator includes:

a clock generator configured to generate a clock signal; and

a waveform shaper configured to adjust a time interval of the clock signal to generate the switching signal.

5. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 2, further comprising:

an amplifier electrically connected to an output port of the pulse generator; and

a high-frequency filter electrically connected to the amplifier and the splitter.

6. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 1, further comprising:

a high-frequency filter electrically connected to an output port of the receiving antenna; and

a low noise amplifier electrically connected to the high-frequency filter and the mixer.

7. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 1, further comprising:

a low-frequency filter electrically connected to an output port of the mixer;

an amplifier electrically connected to an output port of the low-frequency filter; and

a band-pass filter electrically connected to the output port of the amplifier.

8. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 1, wherein the signal-processing module includes a microprocessor having an analog/digital converter configured to convert the cardiopulmonary activity signals into digital signals.

9. The non-contact apparatus for monitoring cardiopulmonary activity signals of claim 8, wherein the signal-processing module further includes an alarm signal generator electrically connected to the microprocessor.

10. The non-contact apparatus for acquiring cardiopulmonary activity signals of claim 1, wherein the mixer is a balance mixer.

11. A method for acquiring cardiopulmonary activity signals, comprising the steps of:

transmitting probing pulses to the chest portion to generate scattered pulses from the probing pulses by the scattering of the cardiopulmonary portion;

generating a phase-difference signal between the scattered pulses and reference pulses by a mixer;

converting the phase-difference signal into a digital signal representing the cardiopulmonary activity; and

checking to determine whether the cardiopulmonary activity is normal and generating an alarm signal if the checking result is negative.

12. The method for acquiring cardiopulmonary activity signals of claim 11, wherein the digital signal is a breathing signal and the step of checking to determine whether the cardiopulmonary activity is normal and generating an alarm signal if the checking result is negative includes:

setting a threshold value;

checking to determine whether the intensity of the digital signal is greater than the threshold value; and

generating the alarm signal if the intensity of the digital signal is not greater than the threshold value for a predetermined interval.

13. The method for acquiring cardiopulmonary activity signals of claim 12, wherein the alarm signal is a suffocation signal.

14. The method for acquiring cardiopulmonary activity signals of claim 11, wherein the digital signal is a heartbeat signal and the step of checking to determine whether the cardiopulmonary activity is normal and generating an alarm signal if the checking result is negative includes:

setting a threshold value;

checking to determine whether the intensity of the digital signal is greater than the threshold value; and

generating the alarm signal if the intensity of the digital signal is not greater than the threshold value for a predetermined interval.

15. The method for acquiring cardiopulmonary activity signals of claim 12, wherein the alarm signal is a cessation signal of the heartbeat.

16. The method for acquiring cardiopulmonary activity signals of claim 11, wherein the threshold value is set according to the intensity of the digital signal.

17. The method for acquiring cardiopulmonary activity signals of claim 11, wherein the probing pulses is a series of high-frequency sinusoidal pulses.

18. A method for acquiring cardiopulmonary activity signals, comprising the steps of:

transmitting probing pulses to the chest portion to generate scattered pulses from the probing pulses by the scattering of the chest portion;

generating a phase-difference signal between the scattered pulses and a reference pulses by a mixer;

converting the phase-difference signal into a digital signal representing the cardiopulmonary activity; and

calculating a frequency of the cardiopulmonary activity based on the digital signal.

19. The method for acquiring cardiopulmonary activity signals of claim 18, wherein the step of calculating a frequency of the cardiopulmonary activity based on the digital signal includes:

setting a threshold value;

checking to determine whether the intensity of the digital signal is greater than the threshold value and determining a signal peak of the cardiopulmonary activity is detected if the checking result is positive;

calculating time intervals of a plurality of signal peaks of the cardiopulmonary activity; and

averaging the time intervals to generate the frequency of the cardiopulmonary activity.

20. The method for acquiring cardiopulmonary activity signals of claim 18, wherein the digital signal is a breathing signal.

21. The method for acquiring cardiopulmonary activity signals of claim 18, further comprising the steps of:

Checking to determine whether the frequency of the cardiopulmonary activity is in a predetermined range; and

generating an alarm signal if the frequency of the cardiopulmonary activity is outside the predetermined range.

22. The method for acquiring cardiopulmonary activity signals of claim 21, wherein the digital signal is a heartbeat signal and the alarm signal is an over-beating signal.

23. The method for acquiring cardiopulmonary activity signals of claim 21, wherein the digital signal is a heartbeat signal and the alarm signal is an under-beating signal.

24. The method for acquiring cardiopulmonary activity signals of claim 18, wherein the threshold value is set according to the intensity of the digital signal.

25. The method for acquiring cardiopulmonary activity signals of claim 18, wherein the probing pulses are a series of high-frequency sinusoidal pulses.