Flex circuit shielded optical sensor

• US 20060084852A1
• Filed: 12/02/2005
• Published: 04/20/2006
• Est. Priority Date: 05/03/2001
• Status: Active Grant

• Current Assignee: Ammar Al-Ali, Gene Mason, Thomas J. Gerhardt
• Original Assignee: Ammar Al-Ali, Gene Mason, Thomas J. Gerhardt
• Inventors: Gerhardt, Thomas J., Al-Ali, Ammar, Mason, Gene
• Granted Patent: US 7,340,287 B2
• Time in Patent Office: Days
• US Class Current: 600/344
• CPC Class Codes: A61B 2562/12 Manufacturing methods specially adapted for producing sensors for in-vivo measurements
• CPC Class Codes: A61B 2562/182 Electrical shielding, e.g. using a Faraday cage
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6833 Adhesive patches
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: H05K 1/0218 by printed shielding conductors, ground planes or power plane H05K1/0236 takes precedence
• CPC Class Codes: H05K 1/189 characterised by the use of a flexible or folded printed circuit H05K3/326 takes precedence
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A flex circuit optical sensor has an integrated Faraday shield. A conductive trace layer disposed on a substrate is used to form a conductive grid which shields the face of a photodetector. A conductive ink layer is formed on a substrate side opposite the trace layer. The back and sides of the detector are shielded by flex circuit flaps that have the conductive ink layer but substantially exclude the trace layer so as to fold over and closely adhere to the detector body. The shielded substrate flaps advantageously eliminate a separate detector shield, which is typically fabricated with an etched copper part that must be attached to a flex circuit before mounting the detector.

Claims

1. An optical sensor comprising:

a plurality of electrical components including at least one detector capable of detecting light attenuated by body tissue; and

an attachment tape including a foldover end including a plurality of end attachment wraps, the plurality of end attachment wraps extending outwardly from the foldover end, a connector end substantially opposite the foldover end, and a central body extended between the foldover end and the connector end, the central body including a plurality of middle attachment wraps, the plurality of middle attachment wraps extending outwardly from the central body and at least one middle attachment wrap extending from the central body to form an approximate boot shape.

2. The optical sensor of claim 1, further comprising an extension extended between the connector end and the central body.

3. The optical sensor of claim 1, wherein the foldover end comprises a generally rectangular flared extension from the central body and wherein the sides of the generally rectangular flared extension comprise the plurality of end attachment wraps.

4. The optical sensor of claim 1, further comprising:

a substrate including a bottom side and a trace side;

an inner coverlay substantially covering the trace side of the substrate;

a top ink layer substantially covering the inner coverlay;

a top coverlay substantially covering the top ink layer;

a bottom ink layer substantially covering the bottom side of the substrate;

a bottom coverlay substantially covering the bottom ink layer;

an adhesive layer at least partially covering the bottom coverlay; and

a release liner substantially covering the adhesive layer, wherein the top coverlay, top ink layer, inner coverlay, substrate, bottom ink layer, and bottom coverlay comprise the plurality of electrical components and wherein the attachment tape substantially covers at least one of the top coverlay and the bottom coverlay.

5. The optical sensor of claim 4, wherein the top coverlay, top ink layer, inner coverlay, substrate, bottom ink layer, and bottom coverlay comprise a flex circuit.

6. The optical sensor of claim 5, wherein the inner coverlay comprises:

a first thru-hole configured to allow the top ink layer to electrically connect with a first portion of the plurality of electrical components;

a second thru-hole configured to allow the top ink layer to electrically connect with the first portion of the plurality of electrical components; and

a third thru-hole configured to allow the top ink layer to electrically connect with a second portion of the plurality of electrical components.

7. An optical sensor comprising:

a plurality of electrical components including at least one detector capable of detecting light attenuated by body tissue; and

a substrate including a first end including at least one flared attachment wing, a second end, and a central body extended between the first end and the second end, the central body including flared attachment wings wherein at least one flared attachment wing extends outwardly from the central body substantially beyond another flared attachment wing extends outwardly from an opposite side of the central body.

8. The optical sensor of claim 7, further comprising an extension extended between the second end and the central body.

9. The optical sensor of claim 7, wherein the first end comprises a generally rectangular flared extension from the central body and wherein the sides of the generally rectangular flared extension comprise the at least one flared attachment wing.

10. The optical sensor of claim 7, wherein the substrate is shaped similar to a boot.

11. The optical sensor of claim 7, further comprising:

a base layer including a bottom side and a trace side;

an inner coverlay substantially covering the trace side of the base layer;

a top ink layer substantially covering the inner coverlay;

a top coverlay substantially covering the top ink layer;

a bottom ink layer substantially covering the bottom side of the base layer;

a bottom coverlay substantially covering the bottom ink layer;

an adhesive layer at least partially covering the bottom coverlay; and

a release liner substantially covering the adhesive layer, wherein the top coverlay, top ink layer, inner coverlay, base layer, bottom ink layer, and bottom coverlay comprise the plurality of electrical components and wherein the substrate substantially covers at least one of the top coverlay and the bottom coverlay.

12. The optical sensor of claim 11, wherein the top coverlay, top ink layer, inner coverlay, base layer, bottom ink layer, and bottom coverlay comprise a flex circuit.

13. The optical sensor of claim 11, wherein the inner coverlay comprises:

a first thru-hole configured to allow the top ink layer to electrically connect with a first portion of the plurality of electrical components;

a second thru-hole configured to allow the top ink layer to electrically connect with the first portion of the plurality of electrical components; and

a third thru-hole configured to allow the top ink layer to electrically connect with a second portion of the plurality of electrical components.

14. A method of attaching an optical sensor comprising:

providing an optical sensor comprising a detector capable of detecting light attenuated by body tissue and an attachment tape, the attachment tape comprising an approximate gourd shape including an upper lobe, a larger lower lobe, and an inwardly tapered section connecting the upper lobe to the lower lobe, wherein a first side of the lower lobe extends outwardly from the inwardly tapered section substantially further than a second side of the lower lobe; and

adhering the optical sensor to an attachment site including body tissue by adhering the upper lobe to a first portion of the attachment site, adhering the second side of the lower lobe to a second portion of the attachment site, and adhering the first side of the lower lobe to a third portion of the attachment site covering the second side of the lower lobe and substantially enclosing the body tissue.

15. The method of claim 14, wherein the attachment site is a finger.

16. The method of claim 15, wherein the first side of the lower lobe terminates distal to a palm of a hand comprising the finger.