OPTICAL VITAL SIGNS SENSOR

• US 20170202466A1
• Filed: 03/31/2017
• Published: 07/20/2017
• Est. Priority Date: 10/02/2014
• Status: Active Grant

• Current Assignee: Koninklijke Philips N.V.
• Original Assignee: Koninklijke Philips N.V.
• Inventors: Paulussen, Elvira Johanna Maria, Cornelissen, Hugo Johan
• Granted Patent: US 10,799,128 B2
• Time in Patent Office: Days
• CPC Class Codes: A61B 2562/0233 Special features of optical sensors or probes classified in A61B5/00
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2562/0242 for varying or adjusting the optical path length in the tissue
• CPC Class Codes: A61B 5/02427 Details of sensor
• CPC Class Codes: A61B 5/02438 with portable devices, e.g. worn by the patient
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: G01N 2021/4752 Geometry
• CPC Class Codes: G01N 2021/4757 Geometry 0/45° or 45/0°
• CPC Class Codes: G01N 21/4795 spatially resolved investigating of object in scattering medium in vivo A61B
• CPC Class Codes: G01N 21/49 within a body or fluid

Abstract

An optical vital signs sensor configured to measure or determine vital signs of a user comprises a light source configured to generate a light beam having an angular range of angles of incidence. The light beam is directed towards the skin of the user. A photo detector is provided and is configured to detect light which is indicative of a reflection of the light beam from the light source in or from the skin of the user. The light source and the photo detector are arranged adjacent to each other and on the same side of the skin of the user. A light shaping unit is configured to shape the light beam of the light source before the light beam enters the skin by limiting the angular range of angle of incidence to less than 20°.

Claims

1. Optical vital signs sensor configured to measure or determine vital signs of a user, comprising a photoplethysmographic sensor having:

a housing with a contact surface configured to be placed directly onto a skin of a user,

at least one light source configured to generate a light beam having an angular range of angles of incidence, wherein said light beam is emitted via the contact surface and is directed towards a skin of the user,

at least one photo detector unit configured to detect light which is indicative of a reflection of the light beam from the at least one light source in or from the skin of the user,

wherein the at least one light source and the at least one photo detector unit are arranged adjacent to each other inside the housing with a distance between them, and

a light shaping unit arranged between the at least one light source and the contact surface and configured to shape the light beam of the at least one light source by limiting the angular range of the angle of incidence (α

) with respect to the contact surface to less than 20°

.

2. Optical vital signs sensor according to claim 1, wherein the light shaping unit comprises an optical film configured to reflect or redirect light beams having a large angle and to transmit light having a small angle.

3. Optical vital signs sensor according to claim 1, wherein the light shaping unit comprises a diffusion chamber configured to recycle light having a large angle.

4. Optical vital signs sensor according to claim 1, wherein the light shaping unit comprises a separation wall having a mirror side between the at least one light source and the at least one photo detector unit.

5. Optical vital signs sensor according to claim 1, wherein the light shaping unit has an optical refractive unit.

6. Optical vital signs sensor according to claim 1, wherein the light shaping unit comprises an optical collimation plate.

7. Optical vital signs sensor according to claim 1, wherein the at least one light source comprises a side emitting light emitting diode, and wherein the at least one light shaping unit comprises a light transport unit which is coupled with its first end to the at least one light source and wherein its distal end comprises an inclination such that light travelling through the light transport unit is reflected towards the skin of a user.

8. Optical vital signs sensor according to claim 1, wherein the at least one light source comprises a plurality of light emitting diodes and wherein the at least one light shaping unit comprises an angle selective film, a diffuser film or a directional turning film.

9. Optical vital signs sensor according to claim 1, wherein the optical vital signs sensor is a wearable device or a wrist device.

11. A computer program product comprising a computer readable memory storing computer program code means for causing the optical vital signs sensor according to claim 1 to carry out the steps of the method of measuring or determining vital signs of a user, when the computer program is run on a computer controlling the optical vital signs sensor.

10. Method of measuring or determining vital signs of a user, comprising the steps of:

placing a contact surface of a housing of a photoplethysmographic sensor against a skin of a user,

generating a light beam having an angular range of angles of incidence by at least one light source in the photoplethysmographic sensor,

directing the light beam towards a skin of the user via the contact surface,

detecting a light which is indicative of a reflection of the light beam from the at least one light source in or from the skin of the user by at least one photo detector unit in the housing of the photoplethysmographic sensor,

wherein the at least one light source and the at least one photo detector are arranged adjacent to each other inside the housing with a distance between them, and

shaping the light beam of the at least one light source in a light shaping unit arranged between the at least one light source and the contact surface of the housing by limiting the angular range of the angle of incidence to less 20°

by means of a light shaping unit.