NIRS SENSOR ASSEMBLY INCLUDING EMI SHIELDING

• US 20140171761A1
• Filed: 12/10/2013
• Published: 06/19/2014
• Est. Priority Date: 12/10/2012
• Status: Active Grant

• Current Assignee: Edwards Lifesciences Corporation
• Original Assignee: Cas Medical Systems Incorporated (Edwards Lifesciences Corporation)
• Inventors: Dalene, Matthew, Duffy, Karen, Gamelin, John, Benni, Paul, Kosturko, William
• Granted Patent: US 9,888,873 B2
• Time in Patent Office: Days
• US Class Current: 600/310
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 2562/222 Electrical cables or leads therefor, e.g. coaxial cables or ribbon cables
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor

Abstract

A NIRS sensor assembly includes a light source, a light detector, a first insulating layer, an EMI shielding layer, and a second insulating layer. The first insulating layer covers an exposed portion of the light detector. An optically transparent portion of the first insulating layer is aligned with an active area of the light detector. The EMI shielding layer covers the first insulating layer. An optically transparent portion of the EMI shielding layer is aligned with the active area of the light detector. The second insulating layer covers the EMI shielding layer and the first insulating layer. An optically transparent portion of the second insulating layer is aligned with the active area of the at least one light detector.

Claims

1. A near-infrared spectroscopy (NIRS) sensor assembly for measurement of a characteristic of a biological tissue, the NIRS sensor assembly comprising:

at least one light source operable to emit light signals;

at least one light detector operable to detect light signals emitted by the light source, the at least one light detector having an active area through which light signals may be detected;

a first insulating layer disposed relative to the at least one light detector in a manner that covers an exposed portion of the at least one light detector, wherein the first insulating layer is electrically non-conductive, and wherein an optically transparent portion of the first insulating layer is aligned with the active area of the at least one light detector;

an electromagnetic interference (EMI) shielding layer disposed in contact with the first insulation layer in a manner that covers the first insulating layer, wherein the EMI shielding layer is electrically conductive, and wherein an optically transparent portion of the EMI shielding layer is aligned with the active area of the at least one light detector; and

a second insulating layer disposed in contact with the EMI shielding layer in a manner that covers the EMI shielding layer and the first insulating layer, wherein the second insulating layer is electrically non-conductive, and wherein an optically transparent portion of the second insulating layer is aligned with the active area of the at least one light detector.

2. The NIRS sensor assembly of claim 1, wherein the first insulating layer includes an electrically non-conductive tape.

3. The NIRS sensor assembly of claim 1, wherein the EMI shielding layer includes a fiber-filled, electrically conductive substrate.

4. The NIRS sensor assembly of claim 1, wherein the second insulating layer includes an electrically non-conductive tape.

5. The NIRS sensor assembly of claim 1, further comprising a flexible circuit in electrical communication with the at least one light source and the at least one light detector.

6. The NIRS sensor assembly of claim 5, wherein the flexible circuit includes a plurality of light source wires configured to communicate electrical signals between the at least one light source and a connector portion of the NIRS sensor assembly.

7. The NIRS sensor assembly of claim 6, wherein the flexible circuit further includes at least one EMI shielding wire disposed relative to the plurality of light source wires so that the at least one EMI shielding wire at least partially defines a Faraday Cage around the plurality of light source wires.

8. The NIRS sensor assembly of claim 5, wherein the flexible circuit includes a plurality of light detector wires configured to communicate electrical signals between the at least one light detector and the connector portion.

9. The NIRS sensor assembly of claim 8, wherein the flexible circuit further includes at least one EMI shielding wire disposed relative to the plurality of light detector wires so that the at least one EMI shielding wire at least partially defines a Faraday Cage around the plurality of light detector wires.

10. The NIRS sensor assembly of claim 5, wherein the flexible circuit comprises a communication layer, a first circuit insulating layer, a second circuit insulating layer, a first circuit shielding layer, and a second circuit shielding layer, wherein the first circuit insulating layer is disposed between the first circuit shielding layer and a first side of the communication layer, and wherein the second circuit insulating layer is disposed between the second circuit shielding layer and an opposing second side of the communication layer.

11. The NIRS sensor assembly of claim 10, wherein the first circuit insulating layer is electrically non-conductive and provides a barrier between the communication layer and the first circuit shielding layer, and wherein the second circuit insulating layer is electrically non-conductive and provides a barrier between the communication layer and the second circuit insulating layer.

12. The NIRS sensor assembly of claim 10, wherein the first circuit shielding layer includes at least one EMI shielding sheet, and wherein the second circuit shielding layer includes at least one EMI shielding sheet.

13. The NIRS sensor assembly of claim 12, wherein the communication layer of the flexible circuit includes a plurality of light source wires configured to communicate electrical signals between the at least one light source and a connector portion of the NIRS sensor assembly, wherein the communication layer includes at least one EMI shielding wire disposed relative to the plurality of light source wires, and wherein the at least one EMI shielding wire, the at least one EMI shielding sheet of the first circuit shielding layer, and the at least one EMI shielding sheet of the second circuit shielding layer at least partially define a Faraday Cage around the plurality of light source wires.

14. The NIRS sensor assembly of claim 12, wherein the communication layer of the flexible circuit includes a plurality of light detector wires configured to communicate electrical signals between the at least one light detector and a connector portion of the NIRS sensor assembly, wherein the communication layer includes at least one EMI shielding wire disposed relative to the plurality of light detector wires, and wherein the at least one EMI shielding wire, the at least one EMI shielding sheet of the first circuit shielding layer, and the at least one EMI shielding sheet of the second circuit shielding layer at least partially define a Faraday Cage around the plurality of light detector wires.

15. The NIRS sensor assembly of claim 5, wherein the flexible circuit includes a plurality of light source wires configured to communicate electrical signals between the at least one light source and a connector portion of the NIRS sensor assembly, wherein the flexible circuit includes a plurality of light detector wires configured to communicate electrical signals between the at least one light detector and a connector portion of the NIRS sensor assembly, and wherein the flexible circuit includes EMI shielding configured to at least partially prevent cross-talk between the plurality of light source wires and the plurality of light detector wires.

16. The NIRS sensor assembly of claim 5, further comprising a third insulating layer disposed in contact with the flexible circuit on a side of the flexible circuit opposite the at least one light source and the at least one light detector.

17. The NIRS sensor assembly of claim 1, further including a luminance measuring device that is operable to measure the luminance of light detected by the at least one light detector.

18. The NIRS sensor assembly of claim 1, further including a temperature measuring device that is operable to measure the temperature of the at least one light detector.

19. A near-infrared spectroscopy (NIRS) sensor assembly for measurement of a characteristic of a biological tissue, the assembly comprising:

a flexible circuit;

a light source in electrical communication with the flexible circuit, wherein the light source is operable to emit light signals;

a light detector in electrical communication with the flexible circuit, wherein the light detector has an active area for detecting light signals emitted by the light source and passed through the subject'"'"'s body tissue;

a connector in electrical communication with the flexible circuit;

a first insulating layer disposed relative to the light detector, wherein the first insulating layer is electrically non-conductive;

an electromagnetic interference (EMI) shielding layer disposed relative to the first insulating layer, wherein the EMI shielding layer is electrically conductive;

a second insulating layer disposed relative to the first insulating layer and the EMI shielding layer, wherein the second insulating layer is electrically non-conductive; and

a pad having a light source aperture and a light detector aperture, wherein the light source is received at least partially within the light source aperture, wherein the light detector is at least partially received within the light detector aperture, and wherein the pad is positioned within the NIRS sensor assembly to contact a subject during operation of the NIRS sensor assembly.

20. A flexible circuit for use in a near-infrared spectroscopy (NIRS) sensor assembly, the flexible circuit being in electrical communication with at least one light source of the NIRS sensor assembly and at least one light detector of the NIRS sensor assembly, the flexible circuit comprising:

a plurality of light source wires configured to communicate electrical signals between the at least one light source and a connector portion of the NIRS sensor assembly;

a plurality of light detector wires configured to communicate electrical signals between the at least one light detector and the connector portion;

EMI shielding configured to at least partially prevent cross-talk between the plurality of light source wires and the plurality of light detector wires.