Multifrequency bioimpedence device and related methods

• US 8,473,047 B2
• Filed: 09/09/2010
• Issued: 06/25/2013
• Est. Priority Date: 08/03/2010
• Status: Active Grant

• Current Assignee: Medtronic Monitoring, Inc. (Medtronic Plc)
• Original Assignee: Corventis Inc (Medtronic Plc)
• Inventors: Chakravarthy, Niranjan, Katra, Rodolphe, Libbus, Imad
• Primary Examiner(s): Hindenburg, Max
• Assistant Examiner(s): DANEGA, RENEE A
• Application Number:
  US12/878,886
• Publication Number:
  US 20120035494A1
• Time in Patent Office: 1,020 Days
• Field of Search: 600/547
• US Class Current: 600/547
• 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: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body

Abstract

Embodiments relate to a device and a method of monitoring and analyzing physiological parameters of a patient. The method includes electrically connecting one or more electrodes with a measurement site of a patient, generating a stimulation signal or signals sufficient to provide multiple stimulation frequencies, multiple waveforms or a combination thereof, measuring a one or more bioimpedance values from the generated signals and analyzing at least one of a fluid bioimpedance contribution, fat bioimpedance contribution or ion bioimpedance contribution within the one or more bioimpedance values sufficient to generate a physiological report.

Claims

1. A medical device, comprising:

a measuring interface, located between a device and a measuring site of a patient;

one or more electrodes to generate a frequency sweep stimulation signal, positioned at the measuring interface and in electrical contact with a portion of the patient;

circuitry to measure total bioimpedance values as a result of the stimulation signal at specific frequencies correlating to the frequency sweep; and

a processor system to a quantify a fluid contribution, an ion contribution, and a fat contribution from the measured total bioimpedance values from which a physiological report can be generated, wherein the processor system further identifies whether a measured total bioimpendance is reliable based a non-fluid contribution.

2. The medical device of claim 1, wherein the measuring interface comprises a patch.

3. The medical device of claim 1, wherein the circuitry is positioned within the device.

4. The medical device of claim 1, wherein the circuitry is positioned remotely from the device.

5. The medical device of claim 1, wherein the processor system is positioned within the device.

6. The medical device of claim 1, wherein the processor system is positioned remotely from the device.

7. The medical device of claim 1, wherein the processor system further operates to distinguish muscle tissue from either the fat content or the fluid content or both.

8. The medical device of claim 1, wherein the frequency sweep includes a frequency where fat is known to resist an electrical current.

9. The medical device of claim 8, wherein the frequency sweep includes a frequency where fluid is known to interact with an electrical current.

10. The medical device of claim 1, wherein the frequency sweep stimulation signal is between about 5 kHz and about 1000 kHz, between about 100 kHz and about 800 kHz, or 50 kHz and about 500 kHz.

11. The medical device of claim 1, wherein identifying whether a measured total bioimpendance is reliable based a non-fluid contribution includes identifying an un-reliable measurement based on a high ion value.

12. A method of monitoring and analyzing physiological parameters of a patient, comprising:

electrically connecting one or more electrodes with a measurement site of a patient;

generating a frequency sweep stimulation signal

measuring, at the measurement site, total bioimpedance values at specific frequencies correlating to the frequency sweep signal;

isolating a fluid bioimpedance contribution, fat bioimpedance contribution and ion bioimpedance contribution from the measured total bioimpedance values, sufficient to generate a physiological report; and

identifying whether a measured total bioimpendance is reliable based a non-fluid contribution.

13. The method of claim 12, wherein generating comprises providing an electrical current between two or more of the one or more electrodes.

14. The method of claim 12, wherein the frequency sweep includes at a frequency where fat is known to resist an electrical current.

15. The method of claim 14, wherein the frequency sweep includes frequency where fluid is known to interact with an electrical current.

16. The method of claim 12, wherein the frequency sweep stimulation signal is between about 5 kHz and about 1000 kHz.

17. The method of claim 12, wherein the frequency sweep stimulation signal is between about 100 kHz and about 800 kHz.

18. The method of claim 12, wherein the frequency sweep stimulation signal is between about 50 kHz and about 500 kHz.

19. The method of claim 12, wherein identifying whether a measured total bioimpendance is reliable based a non-fluid contribution includes identifying an un-reliable measurement based on a high ion value.

20. The method of claim 17, wherein identifying whether a measured total bioimpendance is reliable based a non-fluid contribution includes identifying an un-reliable measurement based on a high ion value.