NZ796480B2

NZ796480B2 - Measurement of tissue viability

Info

Publication number: NZ796480B2
Application number: NZ796480A
Authority: NZ
Inventors: Sara Barrington; Martin F Burns; Graham O Ross
Original assignee: Bbi Medical Innovations Llc
Filing date: 2018-02-02
Publication date: 2025-12-02

Abstract

apparatus for mapping regions of damage around a wound, said apparatus comprising: a sensing apparatus comprising a plurality of electrodes embedded on a substrate configured to be placed over a portion of an area of tissue that includes said wound, wherein combinations of said plurality of electrodes are capable of forming one or more capacitive sensors that is configured to measure a capacitance of a region of tissue proximate to each said capacitive sensor, an optical system comprising a camera that captures said area of tissue that includes said wound, and a projector capable of projecting one or more visual indicators onto said area of tissue that includes said wound, a fiducial on said sensing apparatus that is visible to said camera while said apparatus is in use, a drive circuit electronically coupled to said plurality of electrodes and said optical system, a processor electronically coupled to said drive circuit, and a non-transitory computer-readable medium electronically coupled to said processor and comprising instructions stored thereon that, when executed on said processor, perform the steps of: receiving information regarding one or more of said measured capacitance from one or more of said formed capacitive sensors, determining a first boundary between a first type of tissue and a second type of tissue, and causing said projector to project said one or more visual indicators to indicate said first boundary.

Claims

WE CLAIM:

1. An tus for mapping regions of damage around a wound, said apparatus comprising: a sensing apparatus comprising a plurality of electrodes embedded on a substrate configured to be placed over a portion of an area of tissue that includes said wound, wherein combinations of said plurality of electrodes are capable of forming one or more capacitive sensors that is configured to measure a tance of a region of tissue proximate to each said capacitive sensor, an optical system sing a camera that captures said area of tissue that includes said wound, and a projector capable of projecting one or more visual indicators onto said area of tissue that includes said wound, a fiducial on said sensing apparatus that is visible to said camera while said apparatus is in use, a drive t electronically coupled to said plurality of electrodes and said optical system, a processor electronically coupled to said drive circuit, and a non-transitory computer-readable medium electronically coupled to said processor and comprising instructions stored thereon that, when executed on said processor, perform the steps of: receiving information ing one or more of said measured capacitance from one or more of said formed capacitive sensors, determining a first boundary between a first type of tissue and a second type of , and causing said projector to t said one or more visual indicators to indicate said first boundary.

2. The tus of claim 1, wherein said first type of tissue is a viable tissue, and said second type of tissue is a non-viable tissue.

3. The apparatus of claim 2, wherein said first boundary is identified by: converting each of said one or more measured capacitance to an associated subepidermal moisture (SEM) value that is associated with each said tive sensor used to measure said capacitance, identifying regions of said viable tissue corresponding to said capacitive s that are associated with SEM values that are greater than a threshold, identifying regions of said non-viable tissue ponding to said capacitive sensors that are associated with SEM values that are lesser than said threshold, and indicating said first boundary between said regions of viable and non-viable tissues.

4. The apparatus of claim 1, wherein said instructions further comprise the step of determining a second boundary between said second type of tissue and a third type of tissue.

5. The apparatus of claim 4, n said first type of tissue is a ic tissue, wherein said second type of tissue is a tissue in a zone of stasis, and wherein said third type of tissue is a tissue in a zone of hyperaemia.

6. The apparatus of claim 5, wherein said first and second boundaries are identified by: converting each of said one or more measured capacitance to an associated subepidermal moisture (SEM) value that is associated with each said capacitive sensor used to measure said capacitance, identifying regions of said necrotic tissue corresponding to said capacitive sensors that are associated with SEM values that are lesser than a first threshold, indicating said first boundary on an outer edge of said ic tissue, fying said zone of stasis comprising tissue immediately surrounding said ic tissue and regions of tissue corresponding to said capacitive sensors that are associated with SEM values that are greater than said first threshold up to and including s associated with a peak SEM value, and tissue immediately surrounding said regions associated with said peak SEM value and regions corresponding to said capacitive sensors that are associated with SEM values that are greater than a second threshold, indicating said second boundary on an outer edge of said zone of stasis, and fying said zone of emia comprising tissue immediately surrounding said zone of stasis and regions of tissue corresponding to said capacitive sensors that are associated with SEM values that are lesser than said second threshold but greater than said first threshold.

7. The apparatus of any one of claims 1-6, n said drive circuit is configured to selectively drive ations of said electrodes and measure said capacitance between each of said combinations of electrodes.

8. The apparatus of any one of claims 1-6, wherein said combinations of said electrodes are capable of forming a plurality of virtual capacitive sensors, each of said virtual capacitive s comprising at least two electrodes of said plurality of electrodes and configured to measure a capacitance of a region of tissue proximate to said respective virtual capacitive sensor.

9. The apparatus of claim 8, wherein each of said plurality of virtual capacitive sensors comprises a virtual center electrode and a virtual ring electrode.

10. The tus of any one of claims 1-6 wherein said circuit is configured to selectively drive subsets of said plurality of electrodes to form a virtual center electrode and a virtual ring electrode and ing said capacitance between said virtual center electrode and said l ring ode.

11. The apparatus of any one of claims 1-10, wherein said substrate comprises a plurality of perforations that allow marking of said region of tissue along said boundary.

12. The apparatus of any one of claims 1-11, wherein said visual indicator to indicate said boundary is selected from the group consisting of dots, lines, areas of color, areas shading from a first color to a second color, and areas g from one intensity of a color to a different intensity of the same color.

13. The apparatus of any one of claims 1-6, wherein said combinations of said electrodes comprise one or more pairs of said electrodes capable of forming one or more capacitive sensors.

14. The apparatus of any one of claims 1-13, wherein said camera can e and record the position of said fiducial in its field of view at the time of each measurement. Bruin Biometrics, LLC By the Attorneys for the Applicant SPRUSON & FERGUSON ES CROSS—SECTiON ALONG OCATiON 3mm WES SUBSTRATE 7‘50 VESUALINDECATORS 730 ARRAY m . ELECTRODES PERFORATEONS “ PERFORATEONS 0\ELECTRODES "2’42