US 11,536,653 B2Granted

Multiple light paths architecture and obscuration methods for signal and perfusion index optimization

AssigneeApple Inc.

InventorsChin San Han, Ueyn Block, Brian R. Land, Nevzat Akin Kestelli, Serhan Isikman, Albert Wang, Justin Shi

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Abstract

A photoplethysmographic (PPG) device is disclosed. The PPG device can include one or more light emitters and one or more light sensors to generate the multiple light paths for measuring a PPG signal and perfusion indices of a user. The multiple light paths between each pair of light emitters and light detectors can include different separation distances to generate both an accurate PPG signal and a perfusion index value to accommodate a variety of users and usage conditions. In some examples, the multiple light paths can include the same separation distances for noise cancellation due to artifacts resulting from, for example, tilt and/or pull of the device, a user's hair, a user's skin pigmentation, and/or motion. The PPG device can further include one or more lenses and/or reflectors to increase the signal strength and/or and to obscure the optical components and associated wiring from being visible to a user's eye.

Claims17

Dependent claims

A wearable electronic device comprising:

a first window, a second window, a third window and a fourth window;
an optical isolation separating each of the first, second, third and fourth windows;
a first light sensor positioned behind the first window;
a second light sensor positioned behind the second window;
a first light emitter that emits first light, the first light emitter positioned behind and off-center with respect to the third window, the first light emitter located a first separation distance from the first light sensor and a second separation distance from the second light sensor, wherein the first separation distance is less than the second separation distance;
a second light emitter that emits second light, the second light emitter positioned behind and off-center with respect to the fourth window, the second light emitter located a third separation distance from the second light sensor and a fourth separation distance from the first light sensor, wherein the third separation distance is less than the fourth separation distance;
and
a first lens located between the first light emitter and the third window;
wherein:
the first light sensor detects at least one of the first light and the second light and generates first signals indicative of physiological information of a user;
the second light sensor detects at least one of the first light and the second light and generates second signals indicative of physiological information of the user;
and
the first lens is configured to direct the first light around the optical isolation.

10 more elements

A method of determining physiological information of a user, the method comprising:

at a device having:
a first window and a first light sensor positioned behind the first window,
a second window and a second light sensor positioned behind the second window;
a third window and a first light emitter positioned behind the third window and that emits a first light;
a fourth window and a second light emitter positioned behind the fourth window;
an optical isolation separating each of the first, second, third and fourth windows;
and
a first lens located between the first light emitter and the third window and configured to direct the first light around the optical isolation:
emitting the first light from the first light emitter, the first light emitter positioned off-center within the first window;
receiving a first portion of the emitted first light by the first light sensor, the first light sensor located a first separation distance from the first light emitter;
receiving a second portion of the emitted first light by the second light sensor, the second light sensor located a second separation distance from the first light emitter, wherein the first separation distance is less than the second separation distance;
emitting second light from the second light emitter, the second light emitter positioned off-center within the second window;
receiving a first portion of the emitted second light by the second light sensor, the second light sensor located a third separation distance from the second light emitter;
receiving a second portion of the emitted second light by the first light sensor, the first light sensor located a fourth separation distance from the first light emitter, wherein the third separation distance is less than the fourth separation distance;
and
determining the physiological information using the received first portion of the emitted first light and the received first portion of the emitted second light.

13 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/144,958Filed 27 Sep 2018 · continuation
Priority: 2 Sep 2014
Published: US 2019/0086331 A121 Mar 2019
Granted: 27 Dec 2022
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

G01N 21/4738
Scattering, i.e. diffuse reflection: diffuse reflection , e.g. also for testing fluids, fibrous materials
A61B 5/0059
Measuring for diagnostic purposes ; Identification of persons: using light, e.g. diagnosis by transillumination, diascopy, fluorescence
G01N 21/55
Systems in which incident light is modified in accordance with the properties of the material investigated: specular reflectivity
A61B 5/02416
Measuring pulse rate or heart rate: using photoplethysmograph signals, e.g. generated by infrared radiation

Family

Application62/044,515Us provisional application · filed 2 Sep 2014
Application14/569,235Parent of this continuation · filed 12 Dec 2014
US 2019/0086331 A1Pre-grant publication · published 21 Mar 2019
US 10,215,698 B2Parent of this continuation
US 2016/0058312 A1Published application
US 11,536,653 B2This patent

From the US filing history. Foreign family members aren’t listed.