CONTOURED PROTRUSION FOR IMPROVING SPECTROSCOPIC MEASUREMENT OF BLOOD CONSTITUENTS

• US 20130317370A1
• Filed: 05/06/2013
• Published: 11/28/2013
• Est. Priority Date: 07/03/2008
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Cercacor Laboratories
• Inventors: Dalvi, Cristiano, Lamego, Marcelo, Merritt, Sean, Vo, Hung, Bruinsma, Johannes, Poeze, Jeroen, Olsen, Greg, Kiani, Massi Joe E., Lesmana, Ferydan
• Granted Patent: US 9,591,975 B2
• Time in Patent Office: Days
• US Class Current: 600/476
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/04 Arrangements of multiple sensors of the same type
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 2562/146 for optical coupling
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/14532 for measuring glucose, e.g. by tissue impedance measurement
• CPC Class Codes: A61B 5/14546 for measuring analytes not otherwise provided for, e.g. ions, cytochromes
• CPC Class Codes: A61B 5/1455 using optical sensors, e.g. spectral photometrical oximeters
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/6816 Ear lobe
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/6838 Clamps or clips
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/70 Means for positioning the patient in relation to the detecting, measuring or recording means
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor

Abstract

A noninvasive physiological sensor for measuring one or more physiological parameters of a medical patient can include a bump interposed between a light source and a photodetector. The bump can be placed in contact with body tissue of a patient and thereby reduce a thickness of the body tissue. As a result, an optical pathlength between the light source and the photodetector can be reduced. In addition, the sensor can include a heat sink that can direct heat away from the light source. Moreover, the sensor can include shielding in the optical path between the light source and the photodetector. The shielding can reduce noise received by the photodetector.

Claims

1. A noninvasive medical sensor configured to detect light attenuated by body tissue of a medical patient, the sensor comprising:

a sensor housing comprising an upper shell and a lower shell pivotally connected together, the upper and lower shells each shaped to accept body tissue of a medical patient;

one or more emitters disposed in the housing, the one or emitters configured to impinge light on the body tissue of the patient;

one or more detectors disposed in the housing, the one or more detectors configured to receive the light after attenuation by the body tissue of the patient and to output one or more intensity signals responsive to the attenuated light; and

a tissue thickness adjuster disposed in the housing, the tissue thickness adjuster positioned such that placement of the body tissue of the patient on the tissue thickness adjuster reduces a thickness of the body tissue and thereby increases a gain of the one or more intensity signals.

2. The sensor of claim 1, wherein the tissue thickness adjuster comprises a protrusion configured to deform the body tissue.

3. The sensor of claim 2, wherein the protrusion is a partially cylindrical protrusion.

4. The sensor of claim 3, wherein the partially cylindrical protrusion comprises a lens.

5. The sensor of claim 4, wherein the partially cylindrical protrusion focuses the attenuated light onto the one or more detectors.

6. The sensor of claim 5, wherein the one or more detectors comprise a single row of detectors.

7. The sensor of claim 3, wherein the partially cylindrical protrusion comprises one or more chamfered edges.

8. The sensor of claim 3, wherein the partially cylindrical protrusion is configured to focus the light and thereby increase strength of the one or more intensity signals.

9. The sensor of claim 3, wherein the partially cylindrical protrusion comprises an extension configured to increase a height of the partially cylindrical protrusion.

10. The sensor of claim 1, wherein the tissue thickness adjuster is configured to reduce a pathlength of the light traveling in the tissue.

11. The sensor of claim 1, wherein the tissue thickness adjuster is sized to substantially avoid altering blood flow through said tissue.

12. The sensor of claim 1, wherein the tissue thickness adjuster comprises a protrusion including a curved surface that is generally convex to the measurement site.

13. A noninvasive physiological sensor for measuring one or more physiological parameters of a medical patient, the sensor comprising:

a light source;

a photodetector operative to detect light from said light source after attenuation by body tissue of a medical patient and to generate a physiological signal responsive to the detected light, the physiological signal reflecting one or more physiological parameters of the medical patient; and

a bump interposed between the light source and the photodetector, the bump protruding from a tissue contacting surface, the bump configured to reduce a thickness of the body tissue between the light source and the photodetector such that an optical pathlength between the light source and the photodetector is reduced.

14. The sensor of claim 13, wherein the bump comprises a partially cylindrical lens.

15. The sensor of claim 14, wherein the partially cylindrical lens comprises a height of about 1 mm to 3 mm.

16. The sensor of claim 14, wherein the partially cylindrical lens comprises a width of about 3 mm to 5 mm.

17. The sensor of claim 14, wherein the partially cylindrical lens comprises a radius of curvature of about 1.5 mm to 2 mm.

18. The sensor of claim 14, wherein the partially cylindrical lens comprises an index of refraction of about 1.4 to 1.9.

19. The sensor of claim 18, wherein a value of the index of refraction facilitates optimizing the light focusing properties of the partially cylindrical lens.

20. The sensor of claim 14, wherein the partially cylindrical lens comprises a focal length of about 3 mm to 4 mm.