Determination of biological conditions using impedance measurements

• US 9,017,258 B2
• Filed: 10/10/2003
• Issued: 04/28/2015
• Est. Priority Date: 10/11/2002
• Status: Active Grant

• Current Assignee: Scibase AB (SciBase Holding AB)
• Original Assignee: Scibase AB (SciBase Holding AB)
• Inventors: Ollmar, Stig, Aberg, Peter, Nicander, Ingrid
• Primary Examiner(s): Natnithithadha, Navin
• Application Number:
  US10/682,372
• Publication Number:
  US 20040127780A1
• Time in Patent Office: 4,218 Days
• Field of Search: 600/300, 600/301, 600/306, 600/309, 600345-366, 600372-397, 600/547, 600/546, 600/481, 600/557, 607/149
• US Class Current: 600/306
• CPC Class Codes: A61B 5/0531 Measuring skin impedance
• CPC Class Codes: A61B 5/061 Determining position of a probe within the body employing means separate from the probe, e.g. sensing internal probe position employing impedance electrodes on the surface of the body A61B1/00158 takes precedence
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/411 Detecting or monitoring allergy or intolerance reactions to an allergenic agent or substance
• CPC Class Codes: A61B 5/444 Evaluating skin marks, e.g. mole, nevi, tumour, scar
• CPC Class Codes: A61B 5/6839 Anchoring means, e.g. barbs

Abstract

Apparatus and methods for the diagnostics of biological conditions using impedance measurements.

Claims

1. A method for diagnosing a diseased condition of the skin using an apparatus for the diagnosing of a diseased condition of the skin of a subject comprising an electrical probe for obtaining impedance data from a tissue region and an electronic control unit, the method comprising the steps of:

(i) placing an electrical conducting probe against a skin surface of the subject, wherein the probe comprises at least three electrodes, each electrode furnished with a number of spikes, the spikes being laterally spaced apart from each other and being of sufficient length to penetrate the stratum corneum, wherein a first electrode and a second electrode of the at least three electrodes are spaced a first distance from each other and wherein the first electrode and a third electrode of said at least three electrodes are spaced a second distance from each other;

(ii) using an electronic control unit connected to the probe to

pass an electrical current through the electrodes, wherein said electrical current is separately passed between the first and the second electrode and between the first and the third electrode,

measure a resulting voltage between the first and the second electrode and between the first and the third electrode, and

determine a first value of impedance based on the electrical current between the first and second electrode and the resulting voltage between the first and second electrode and a second value of impedance based on the electrical current between the first and third electrode and the resulting voltage between the first and third electrode; and

(iii) using reference data to determine whether the first and second impedance values indicate the diseased condition by comparing the first and second impedance values with the reference data.

2. The method of claim 1, wherein the diseased condition is cancer.

3. The method of claim 2, wherein said cancer is a skin cancer selected from the group consisting of basal cell sarcoma, malignant melanoma, squamous cell carcinoma, or precursors of such lesions.

4. A method according to claim 1, wherein each spike is at least 10 pm in length.

6. The method of claim 1, wherein the first distance is between about 0.1 mm and about 40 mm;

or between about 0.1 mm and 30 mm;

or between about 0.1 mm and 25 mm;

or between about 0.1 mm and 20 mm;

or between about 0 1 mm and 15 mm;

or between about 0.2 mm and 10 mm;

or between about 0.2 mm and 8 mm;

or between about 0.2 mm and 5 mm;

or between about 0.2 mm and 3 mm;

or between about 0.2 mm and 2 mm;

or between about 0.2 mm and 1.5 mm;

or between about 0.2 mm and 1 mm;

or between about 0.2 mm and 0.5 mm.

7. The method of claim 6, wherein the second distance is between about 1 mm and about 50 mm;

or between about 1 mm and 40 mm;

or between about 1 mm and 30 mm;

or between about 1 mm and 25 mm;

or between about 1 mm and 20 mm;

or between about 1 mm and 15 mm;

or between about 1 mm and 10 mm;

or between about 1 mm and 9 mm;

or between about 1 mm and 8 mm;

or between about 1 mm and 7 mm;

or between about 2 mm and 8 mm;

or between about 3 mm and 7 mm;

or between about 4 mm and 7 mm;

or between about 4 mm and 6 mm;

or about 5 mm.

8. The method of claim 1, wherein for each electrode, there are at least two said spikes, or at least three said spikes, or at least four said spikes, or at least five said spikes, or at least six said spikes, or at least seven said spikes, or at least eight said spikes, or at least nine said spikes, or at least ten said spikes, or at least twelve said spikes, or at least fifteen said spikes, or at eighteen said spikes, or at least twenty said spikes, or at least twenty-five said spikes, or at least thirty said spikes, or at least thirty-five said spikes, or at least fifty said spikes.

9. The method of claim 1, wherein each said spike is up to 250, or up to 240, or up to 230, or up to 220, or up to 210, or up to 200, or up to 190 or up to 180 or up to 170 or up to 160 or up to 150 or up to 140 or up to 130 or up to 120 or up to 110 or up to 100 pm in length.

10. The method of claim 1, wherein each said spike is at least 20, or at least 30 or at least 40 or at least 50, or at least 60 or is at least 70 or is at least 80 or is at least 90 pm in length.

11. The method of claim 1, wherein each said spike is of sufficient length to penetrate below the skin surface to the stratum germinativum or through the stratum corneum into the living epidermis but not into the dermis.

12. The method of claim 1, wherein the outer diameter of each spike is between about 20 pm and about 50 pm.

13. The method of claim 1, wherein said electrical current has a frequency of between about 10 Hz and about 10 MHz.

14. The method of claim 13, wherein step (ii) is conducted a first time at a first said frequency, and step ii is conducted a second time at a second said frequency.

15. The method of claim 1, wherein both non-invasive surface electrodes (conventional probes) are used in conjunction with said minimally invasive spiked electrodes to catch more aspects of skin properties in order to improve power of discrimination.

16. The method of claim 1, wherein said electrical current is passed between the first electrode and the second electrode and between the first electrode and the second electrode at different time.

5. The method of claimer 1, wherein the first and second distances are different from each other.

17. An apparatus for the diagnosing of a diseased condition of the skin of a subject, said apparatus comprising:

an electrically conducting probe including at least three electrodes for obtaining impedance data from a tissue region, each electrode comprising at least one spike, which spikes are laterally spaced apart from each other and having a length being sufficient to penetrate the stratum corneum, wherein a first electrode and a second electrode of the at least three electrodes are spaced a first distance from each other and wherein the first electrode and a third electrode of said at least three electrodes are spaced a second distance from each other, and

an electronic control unit connected to the probe and configured to, when the probe is placed against a skin surface of the subject such that said spikes penetrate the stratum corneum,

pass an electrical current through the electrodes, wherein said electrical current is separately passed between the first and the second electrode and between the first and the third electrode,

measure a resulting voltage between the first and the second electrode and between the first and the third electrode,

determine a first value of impedance based on the electrical current between the first and second electrode and the resulting voltage between the first and second electrode and a second value of impedance based on the electrical current between the first and third electrode and the resulting voltage between the first and third electrode, and

use reference data to determine whether the impedance values indicate the diseased condition by comparing the first and second impedance values with the reference data.

18. The apparatus according to claim 17, wherein the diseased condition is cancer.

19. The apparatus according to claim 18, wherein said cancer is skin cancer selected from the group consisting of basal cell sarcoma, malignant melanoma, squamous cell carcinoma, or precursors of such lesions.

20. The apparatus according to claim 17, wherein each spike has a length of at least about 10 pm.

21. The apparatus according to claim 17, wherein said first distance and said second distance are different from each other.

22. The apparatus according to claim 17, wherein said first distance is between about 0.1 mm and about 40 mm;

or between about 0.1 mm and 30 mm;

or between 0.1 mm and 25 mm;

or between about 0.1 mm and 20 mm;

or between about 0.1 mm and 15 mm, or between about 0.2 mm and 10 mm;

or between about 0.2 mm and 8 mm;

or between about 0.2 mm and 5 mm;

or between about 0.2 mm and 3 mm;

or between about 0.2 mm and 2 mm;

or between 0.2 mm and 1.5 mm;

or between about 0 2 mm and 1 mm;

or between about 0.2 mm and 0.5 mm.

23. The apparatus according to claim 17, wherein said second distance is between about 1 mm and about 50 mm;

or between about 1 mm and 40 mm;

or between about 1 mm and 30 mm;

or between about 1 mm and 25 mm;

or between about 1 mm and 20 mm;

or between about 1 mm and 15 mm;

or between about 1 mm and 10 mm;

or between about 1 mm and 9 mm;

or between about 1 mm and 8 mm;

or between about 1 mm and 7 mm;

or between about 2 mm and 8 mm;

or between about 3 mm and 7 mm;

or between about 4 mm and 7 mm;

or between 4 mm and 6 mm;

or about 5 mm.

24. The apparatus according to claim 17, wherein each electrode comprises at least two said spikes;

or at least three said spikes;

or at least four said spikes;

or at least five said spikes;

or at least six said spikes;

or at least seven said spikes;

or at least eight said spikes;

or at least nine said spikes;

or at least ten said spikes;

or at least twelve said spikes;

or at least fifteen said spikes;

or at least eighteen said spikes;

or at least twenty said spikes;

or at least twenty-five said spikes;

or at least thirty said spikes;

or at least thirty-five said spikes;

or at least fifty said spikes.

25. The apparatus according to claim 17, wherein each of said spikes has a length up to about 250 pm, or up to 240 pm, or up to 230 pm, or up to 220 pm, or up to 210 pm, or up to 200 pm, or up to 190 pm, or up to 180 pm, or up to 170 pm, or up to 160 pm, or up to 150 pm, or up to 140 pm, or up to 130 pm, or up to 120 pm, or up to 110 pm, or up to 100 pm.

26. The apparatus according to claim 17, wherein each spike is at least 20;

or at least 30;

or at least 40;

or at least 50;

or at least 60;

or at least 70;

or at least 80, or at least 90 pm in length.

27. The apparatus according to claim 17, wherein each of said spikes has a length being sufficient to penetrate below the skin surface to the stratum germinativum or through the stratum corneum into the living epidermis but not into the dermis.

28. The apparatus according to claim 17, wherein an outer diameter of each of said spikes is between about 20 pm and about 50 pm.

29. The apparatus according to claim 17, wherein said electrical current has a frequency between about 10 Hz and about 10 MHz.

30. The apparatus according to claim 17, wherein said apparatus is adapted to use both non-invasive surface electrodes in conjunction with said spiked electrodes to obtain more aspects of skin properties in order to improve power of discrimination.