OPTICAL SENSOR PATH SELECTION

• US 20100130840A1
• Filed: 11/13/2009
• Published: 05/27/2010
• Est. Priority Date: 11/14/2008
• Status: Active Grant

• Current Assignee: Nonin Medical Incorporated
• Original Assignee: Nonin Medical Incorporated
• Inventors: Isaacson, Philip O.
• Granted Patent: US 8,725,226 B2
• Time in Patent Office: Days
• US Class Current: 600/323
• CPC Class Codes: A61B 2503/045 Newborns, e.g. premature baby monitoring
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 2562/043 in a linear array
• CPC Class Codes: A61B 2562/228 Sensors with optical connectors
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/14553 specially adapted for cerebral tissue
• CPC Class Codes: A61B 5/6814 Head

Abstract

A device includes a sensor for measuring a parameter for tissue. The sensor includes a plurality of optical elements including a plurality of detectors and at least one emitter. Separation distances between the various optical elements are selected based on a depth corresponding to a region of interest in the tissue and based on a depth corresponding to an exclusion region in the tissue.

Claims

1. A device comprising:

a housing having a surface for coupling to a biological tissue;

a first emitter and a second emitter coupled to the surface;

a first detector and a second detector coupled to the surface, the first detector having a first output and the second detector having a second output, wherein the first emitter and the second detector are separated by a first dimension and the second emitter and the first detector are separated by approximately the first dimension, the first dimension selected to correspond with a region of interest in a first layer of the biological tissue, the first emitter and the first detector are separated by a second dimension and the second emitter and the second detector are separated by approximately the second dimension, the second dimension selected to correspond with an exclusion region in a second layer of the biological tissue, the first layer having a first depth below the surface and the second layer having a second depth below the surface, the first depth greater than the second depth; and

a port coupled to the housing and configured to communicate at least one of the first output or the second output to a module.

2. The device of claim 1 wherein the first dimension is approximately 40 mm.

3. The device of claim 1 wherein the first dimension is approximately 25 mm.

4. The device of claim 1 wherein the housing is configured for adhering to a forehead.

5. The device of claim 1 wherein at least one of the first emitter and the second emitter includes a light emitting diode (LED).

6. A system comprising:

a sensor configured to couple with a biological tissue, the sensor having a first emitter, a first detector, a second emitter, and a second detector, the first detector having a first output and the second detector having a second output, wherein the first emitter and the second detector are separated by a first dimension and the second emitter and the first detector are separated by approximately the first dimension, the first dimension selected to correspond with a region of interest in a first layer of the biological tissue, the first emitter and the first detector are separated by a second dimension and the second emitter and the second detector are separated by approximately the second dimension, the second dimension selected to correspond with an exclusion region in a second layer of the biological tissue, the first layer having a first depth below the surface and the second layer having a second depth below the surface, the first depth greater than the second depth; and

a processor coupled to the sensor and configured to generate a processor output using the first output and the second output, the processor output corresponding to a physiological parameter of the biological tissue.

7. The system of claim 6 wherein the first dimension is approximately 40 mm.

8. The system of claim 6 wherein the first dimension is approximately 25 mm.

9. The system of claim 6 wherein the sensor includes a surface configured to couple with the biological tissue, the first emitter and the second emitter configured to emit light through the surface and the first detector and the second detector configured to receive light through the surface.

10. The system of claim 6 wherein the processor is coupled to the sensor by at least one of a wired or wireless link.

11. The system of claim 6 wherein the processor output corresponds to oximetry of the biological tissue.

12. A method comprising:

identifying a region of interest disposed in a first layer of a biological tissue;

identifying an exclusion region disposed in a second layer of the biological tissue, the first layer exclusive of the second layer and the first layer having a greater depth than the second layer;

selecting a first depth corresponding to the region of interest;

selecting a second depth corresponding to the exclusion region;

using the first depth to determine a first dimension between a first emitter and a second detector and between a second emitter and a first detector, the first detector configured to generate a first output and the second detector configured to generate a second output;

using the second depth to determine a second dimension between the first emitter and the first detector and between the second emitter and the second detector;

using the first dimension to position the first emitter relative to the second detector in a housing of a sensor and to position the second emitter relative to the first detector in the housing; and

using the second dimension to position the first emitter relative to the first detector and to position the second emitter relative to the second detector in the housing, the sensor configured to determine a physiological parameter of the biological tissue.

13. The method of claim 12 wherein selecting the first dimension includes selecting approximately 40 mm.

14. The method of claim 12 wherein selecting the second dimension includes selecting approximately 20 mm.

15. The method of claim 12 wherein selecting the first dimension includes selecting approximately 25 mm.

16. The method of claim 12 wherein selecting the second dimension includes selecting approximately 12.5 mm.

17. A method comprising:

determining a first depth corresponding to a region of interest and a second depth corresponding to an exclusion region;

selecting a first dimension using the first depth and a second dimension using the second depth; and

configuring an arrangement of optical elements for a sensor, the optical elements including a plurality of at least two detectors and at least one emitter, the arrangement corresponding to the first dimension and to the second dimension, wherein the at least two detectors includes a first detector having a first output and including a second detector having a second output, the first output and the second output corresponding to detected light, the detected light from the at least one emitter and traversing the region of interest and traversing the exclusion region.

18. The method of claim 17 wherein configuring the arrangement of optical elements includes separating a first emitter of the at least one emitter and a second detector of the plurality of detectors by the first dimension and separating the first emitter and a first detector of the plurality of detectors by the second dimension.

19. The method of claim 17 wherein configuring the arrangement of optical elements includes separating a first emitter of the at least one emitter and the first detector of the plurality of detectors by the second dimension, separating a second emitter of the at least one emitter and a second detector of the plurality of detectors by approximately the second dimension, separating the first emitter and the second detector by the first dimension, and separating the second emitter and the first detector by approximately the first dimension.

20. The method of claim 17 wherein the first dimension is in the range of approximately 25-40 mm.