Spread spectrum measurement device

• US 20020136264A1
• Filed: 03/20/2001
• Published: 09/26/2002
• Est. Priority Date: 03/20/2001
• Status: Abandoned Application

• Current Assignee: Agilent Technologies Europe BV (Agilent Technologies, Inc.)
• Original Assignee: Agilent Technologies Europe BV (Agilent Technologies, Inc.)
• Inventors: Lindauer, James M., Elschenbroich, Rainer, Baumgartner, Richard A., Woehrle, Dieter, Miller, James L., Herleikson, Earl C.
• Application Number:
  US09/812,431
• Publication Number:
  US 20020136264A1
• Time in Patent Office: Days
• US Class Current: 375/130
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 8/02 Measuring pulse or heart rate
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 2201/70715 with application-specific features

Abstract

The present disclosure relates to a spread spectrum measurement device with which a desired condition can be measured. In use, the spread spectrum measurement device is used to direct a spread spectrum signal into medium (e.g., a patient'"'"'s body), detect a parameter that corresponds to the signal directed into the medium, generate a measured parameter signal from the detected parameter, and analyze the measured parameter signal to determine the desired condition. In one arrangement, a spread spectrum current signal is transmitted into the medium and a voltage signal is detected. From this voltage signal, an impedance signal is generated with which electrode contact impedance, patient heart rate, and/or patient respiration rate can be measured.

Claims

1. A method for measuring a desired condition, comprising:

directing a spread spectrum signal into a medium;

detecting a parameter that corresponds to the signal directed into the medium;

generating a measured parameter signal from the detected parameter; and

analyzing the measured parameter signal to determine the desired condition.

2. The method of claim 1, wherein the steps of directing a spread spectrum signal into a medium comprises transmitting a spread spectrum current signal into the medium.

3. The method of claim 2, wherein the steps of detecting a parameter that corresponds to the signal directed into the medium comprises measuring a voltage signal.

4. The method of claim 1, wherein the steps of directing a spread spectrum signal into a medium comprises transmitting a spread spectrum voltage signal into the medium.

5. The method of claim 4, wherein the steps of detecting a parameter that corresponds to the signal directed into the medium comprises measuring a current signal.

6. The method of claim 1, wherein the steps of generating a measured parameter signal from the detected parameter comprises generating an impedance signal.

7. The method of claim 6, wherein the steps of analyzing the measured parameter signal to determine the desired condition comprises analyzing the impedance signal to determine a contact impedance of a device electrode.

8. The method of claim 6, wherein the steps of analyzing the measured parameter signal to determine the desired condition comprises analyzing the impedance signal to determine a heart rate of a patient.

9. The method of claim 6, wherein the steps of analyzing the measured parameter signal to determine the desired condition comprises analyzing the impedance signal to determine a respiration rate of a patient.

10. The method of claim 1, wherein the steps of directing a spread spectrum signal into a medium comprises transmitting a spread spectrum ultrasound signal into the medium.

11. The method of claim 10, wherein the steps of analyzing the measured parameter signal to determine the desired condition comprises analyzing echoes of the ultrasound signal to determine the heart rate of a patient.

12. The method of claim 1, wherein the steps of directing a spread spectrum signal into a medium comprises transmitting a spread spectrum light signal into the medium.

13. The method of claim 12, wherein the steps of analyzing the measured parameter signal to determine the desired condition comprises analyzing detected red and/or infrared light level to determine the oxygenation level of a patient'"'"'s blood.

14. The method of claim 1, further comprising generating a clock signal that is used to spread the signal directed into the medium across a desired frequency.

15. The method of claim 14, further comprising randomizing the clock signal.

16. The method of claim 15, wherein the clock signal is randomized with a random number generator and a divider.

20. The device of claim 19, wherein the signal transmitter transmits a spread spectrum electrical signal.

21. The device of claim 19, wherein the signal transmitter transmits a spread spectrum ultrasound signal.

22. The device of claim 19, wherein the signal transmitter transmits a spread spectrum light signal.

23. The device of claim 19, further comprising a random signal generator in electrical communication with the signal transmitter and the signal detector.

17. A spread spectrum measurement device, comprising:

means for directing a spread spectrum signal into a medium;

means for detecting a parameter that corresponds to the signal directed into the medium;

means for generating a measured parameter signal from the detected parameter; and

means for analyzing the measured parameter signal to determine a desired condition.

18. A spread spectrum measurement device at least partially comprised within a computer readable medium, comprising:

logic configured to direct a spread spectrum signal into a medium;

logic configured to detect a parameter that corresponds to the signal directed into the medium;

logic configured to generate a measured parameter signal from the detected parameter; and

logic configured to analyze the measured parameter signal to determine a desired condition.

19. A spread spectrum measurement device, comprising:

a medium interface;

a signal transmitter configured to produce a spread spectrum input signal, the signal transmitter being in electrical communication with the medium interface;

a signal detector configured to detect a spread spectrum signal at the medium interface, the signal detector being in electrical communication with the medium interface; and

a signal processor configured to analyze the spread spectrum signal detected by the signal detector.