Preparation for transmission and reception of electrical signals

• US 6,887,239 B2
• Filed: 04/11/2003
• Issued: 05/03/2005
• Est. Priority Date: 04/17/2002
• Status: Active Grant

• Current Assignee: Echo Therapeutics Incorporated
• Original Assignee: Sontra Medical, Inc. (Echo Therapeutics Incorporated)
• Inventors: DiMatteo, Steve, Elstrom, Tuan A., Kellogg, Scott, Mitragotri, Samir S., Kost, Joseph, Warner, Nicolas F.
• Primary Examiner(s): Gibson, Roy D.
• Assistant Examiner(s): ROANE, AARON F
• Application Number:
  US10/411,156
• Publication Number:
  US 20040039418A1
• Time in Patent Office: 753 Days
• Field of Search: 601/2, 601/3, 606/32, 606/41, 606/47, 606/49, 607115-116, 600373-386, 600508-528
• US Class Current: 606/41
• CPC Class Codes: A61B 5/0048 Detecting, measuring or recording by applying mechanical forces or stimuli A61B5/021, A61B5/4884 and A61B9/00 take precedence
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 8/4236 characterised by adhesive patches
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/4455 Features of the external shape of the probe, e.g. ergonomic aspects
• CPC Class Codes: A61N 1/0408 Use-related aspects
• CPC Class Codes: A61N 1/0472 Structure-related aspects
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092

Abstract

The invention provides a convenient and non-invasive means to prepare cells, tissues, and organs for electrical transmission and reception. In an embodiment of the invention, a control method comprises the use of at least one skin electrode, as a reference electrode, and an electrical sensor to measure periodically or continuously the skin'"'"'s electrical conductance at the site of preparation. The dynamic change in the conductance through the skin is measured while the ultrasound is applied. Signal processing is performed on the measurement and the level of skin impedance change is controlled by performing a mathematical analysis and using the results of such analysis to control the application of ultrasonic energy. A desired level of skin impedance can be set at a predetermined value or based on a chosen level of skin integrity, subject'"'"'s sensation of discomfort, or duration of the ultrasound application.

Claims

1. A method for enhancing the transmission and reception of electrical signals through a tissue site comprising the steps of:

applying ultrasound to a tissue site to decrease an impedance of said tissue site, and

affixing an electrode in proximity to said tissue site.

2. The method of claim 1, further comprising the step of

measuring an electrical parameter of said tissue site.

3. The method of claim 2, wherein said electrical parameter corresponds to an impedance value of said tissue site.

4. The method of claim 3, further comprising the step of

matching an impedance of said electrode to said impedance value of said tissue site.

5. The method of claim 3, further comprising the steps of:

analyzing said electrical parameter, and

controlling said ultrasound application based on results of said analysis.

6. The method of claim 5, wherein said step of analyzing comprises the step of

processing said measured electrical parameter to derive said impedance value of said tissue preparation site.

7. The method of claim 6, wherein said step of controlling comprises the step of

discontinuing application of said ultrasound when said derived impedance value is substantially equal to or exceeds a predetermined value.

8. The method of claim 2, wherein said step of measuring an electrical parameter of said tissue site is performed during said step of applying ultrasound.

9. The method of claim 2, wherein said step of measuring an electrical parameter of said tissue site comprises the steps of:

affixing a first electrical lead to said tissue site,

affixing a second electrical lead to a reference tissue site, and

applying an electrical potential difference between said first and second electrical leads.

10. The method of claim 9, wherein said electrical potential difference is an alternating current potential.

11. The method of claim 9, wherein said electrical parameter is a current amount flowing between said tissue site and said reference tissue site.

12. The method of claim 2, wherein said electrical parameter is selected from the group consisting of:

current value, current value change during a specified time period, instantaneous rate of current value change, impedance value at said tissue site, impedance value change at said tissue site during a specified time period, difference of impedance values between said tissue site and said reference tissue site.

13. The method of claim 1, wherein said step of applying said ultrasound to said tissue site comprises the steps of:

affixing an interface receptacle to said application tissue site, and

holding an ultrasound source against said interface receptacle.

14. The method of claim 13, wherein said electrode is affixed to said interface receptacle upon termination of said step of applying said ultrasound to said tissue site.

15. The method of claim 1, further comprising the step of

acquiring a bioelectrical signal at said tissue preparation site via said electrode.

16. A method for measuring bioelectrical signals comprising the steps of:

applying ultrasound to a tissue site to decrease an impedance of said tissue site,

placing a biosensor electrode in proximity to said tissue site, and

measuring a bioelectric signal generated at said biosensor electrode.

17. The method of claim 16, further comprising the step of

measuring an impedance value of said tissue site.

18. The method of claim 17, further comprising the step of

matching an impedance of said biosensor electrode to said impedance value of said tissue site.

19. The method of claim 17, wherein said step of measuring said impedance value of said tissue site comprises the steps of:

affixing a first electrical lead to said tissue site,

affixing a second electrical lead to a reference tissue site, and

applying an electrical potential difference between said first and second electrical leads.

20. The method of claim 16, wherein said step of applying said ultrasound to said tissue site comprises the steps of:

affixing an interface receptacle to said application tissue site, and

holding an ultrasound source against said interface receptacle.

21. The method of claim 20, wherein said biosensor electrode is affixed to said interface receptacle upon termination of said step of applying said ultrasound to said tissue site.

22. The method of claim 16, further comprising the step of

acquiring a bioelectrical signal at said tissue preparation site via said biosensor electrode.