A configurable photoplethysmogram system

Abstract

Methods, systems, and devices for measuring optical signals are described. [Solution] A wearable electronic device may activate a first combination of optical sensors, the first combination of optical sensors including a set of transmitter sensors and a set of receiver sensors. In some cases, one or more optical sensors of the first combination of optical sensors may be located under a protrusion on the inner surface of the wearable electronic device. The device may measure one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time, determine a signal quality metric associated with one or more signals, and select a second combination of optical sensors for use at a second time based on the signal quality metric.

Description

Technical Field

[0001] This application claims the benefit of U.S. Non-Provisional Application No. 17 / 963,561, filed Oct. 11, 2022, by Vallius et al. entitled “CONFIGURABLE PHOTOPLETHYSMOGRAM SYSTEM,” which claims the benefit of U.S. Provisional Application No. 63 / 255,140, filed Oct. 13, 2021, by Vallius et al. entitled “CONFIGURABLE PHOTOPLETHYSMOGRAM SYSTEM,” and is assigned to the assignee of this application and is hereby expressly incorporated herein by reference.

[0002] The following relates to wearable devices and data processing including a configurable photoplethysmogram (PPG) system.

Background Art

[0003] Some wearable devices can be configured to collect data from a wearer using a PPG signal. The PPG signal can be used to derive several other physiological parameters such as heart rate, heart rate variability, etc. However, existing techniques for collecting PPG data using sensors of wearable devices can be improved.

Brief Description of the Drawings

[0004] Embodiments of the present invention will be described below based on the drawings.

[0005] [Figure 1] An example of a system supporting a configurable PPG system according to an aspect of the present disclosure is shown. [Figure 2] An example of a system supporting a configurable PPG system according to an aspect of the present disclosure is shown. [Figure 3] An example of a wearable electronic device supporting a configurable PPG system according to an aspect of the present disclosure is shown. [Figure 4]Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 5] Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 6] Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 7] Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 8] Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 9] Examples of wearable electronic devices supporting a configurable PPG system according to aspects of this disclosure are shown. [Figure 10] An example of a process flow supporting a configurable PPG system according to the aspects of this disclosure is shown. [Figure 11] A block diagram of an apparatus supporting a configurable PPG system according to aspects of this disclosure is shown. [Figure 12] A block diagram of a wearable device manager supporting a configurable PPG system according to the embodiments of this disclosure is shown. [Figure 13] A diagram of a system including devices supporting a configurable PPG system according to an aspect of this disclosure is shown. [Figure 14] A flowchart illustrating a method for supporting a configurable PPG system according to the aspects of this disclosure is provided. [Figure 15] A flowchart illustrating a method for supporting a configurable PPG system according to the aspects of this disclosure is provided. [Figure 16] A flowchart illustrating a method for supporting a configurable PPG system according to the aspects of this disclosure is provided. [Modes for carrying out the invention]

[0006] Wearable electronic devices, such as wearable electronic rings (e.g., rings), may include a PPG system that measures the user's pulse waveform. A PPG system may include one or more optical transmitters and one or more optical receivers. In some examples, an optical transmitter (e.g., a light-emitting diode (LED)) may transmit one or more wavelengths of light, such as infrared (IR), red, yellow, blue, and / or green wavelengths. Some devices may include two or more optical transmitters configured to transmit light based on a trigger (e.g., configured periodicity, lack of motion, etc.). However, several factors may exist that affect the quality of the measured signal from the activated optical transmitters (e.g., motion, position of the wearable relative to the skin, ambient light, etc.). Therefore, techniques for selecting optical transmitters and optical receivers to activate based on the measured signal quality or other quality metrics may be desirable to improve the accuracy of the measured signal.

[0007] According to aspects of this disclosure, a PPG system may select a transmitter and receiver used to measure the user's pulse waveform. For example, the PPG system may select a transmitter-receiver combination based on various factors such as signal strength, signal quality, user movement, time of day, temperature (e.g., ambient temperature, skin temperature), motion (e.g., acceleration), and power consumption. As another example, the PPG system may select different transmitter wavelengths based on other considerations such as ambient light.

[0008] The PPG system may transition between different transmitter-receiver combinations and wavelengths over time based on changing circumstances. Since finger characteristics such as skin tone, thickness, and blood circulation can vary across different parts of the finger, different configurable PPG transmitter / receiver arrangements can help ensure the ring can acquire high-quality PPG signals for different rotational orientations on the finger. In addition, the availability of different transmitter wavelengths can provide options for acquiring PPG signals in different scenarios (e.g., while the user is moving or sleeping).

[0009] For example, a wearable device may activate a first combination of optical sensors. The first combination of optical sensors may include a set of transmitter sensors from a plurality of transmitter sensors of the wearable electronic device and a set of receiver sensors from a plurality of receiver sensors. In some cases, the plurality of transmitter sensors may include at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength. In some implementations, at least one optical sensor of the first combination of optical sensors may be located under a protrusion on the inner surface of the wearable electronic device. The wearable device may measure one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time and determine a signal quality metric associated with one or more signals. Based on the signal quality metric, the wearable device may select a second combination of optical sensors for use at a second time.

[0010] The aspects of this disclosure are first described in the context of a system that supports the collection of physiological data from a user via a wearable device. The aspects are then described with reference to examples of wearable electronic devices and process flows. The aspects of this disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flowcharts relating to a configurable PPG system.

[0011] Figure 1 shows an example of a system 100 supporting a configurable PPG system according to an aspect of the present disclosure. The system 100 includes a plurality of electronic devices (e.g., wearable devices 104, user devices 106) that can be worn and / or operated by one or more users 102. The system 100 further includes a network 108 and one or more servers 110.

[0012] The electronic devices may include any electronic devices known in the art, including wearable devices 104 (e.g., ring wearable devices, watches or wrist-worn wearable devices, etc.) and user devices 106 (e.g., smartphones, laptops, tablets). Each electronic device associated with a user 102 may include one or more of the following functions: 1) measuring physiological data, 2) storing the measured data, 3) processing the data, 4) providing output to the user 102 based on the processed data (e.g., via a GUI), and 5) communicating data with each other and / or other computing devices. Different electronic devices may perform one or more of these functions.

[0013] An exemplary wearable device 104 may include wearable computing devices such as a ring computing device (hereinafter, "ring") configured to be worn on the finger of user 102, a wrist computing device (e.g., a smartwatch, fitness band, or bracelet) configured to be worn on the wrist of user 102, and / or a head-mounted computing device (e.g., glasses / goggles). The wearable device 104 may also include bands, straps (e.g., flexible or non-flexible bands or straps), stick-on sensors, etc., which may be positioned around the head (e.g., a forehead headband), arms (e.g., a forearm band and / or a biceps band), and / or legs (e.g., a thigh or calf band), behind the ear, under the armpit, and other locations. The wearable device 104 may be attached to or incorporated into clothing. For example, the wearable device 104 may be incorporated into a pocket and / or pouch of clothing. As another example, the wearable device 104 may be clipped and / or pinned to clothing, or otherwise maintained within the vicinity of the user 102. Exemplary clothing may include, but is not limited to, hats, shirts, gloves, trousers, socks, outerwear (e.g., jackets), and underwear. In some implementations, the wearable device 104 may be included with other types of devices, such as training / sports devices used during physical activity. For example, the wearable device 104 may be attached to or included with bicycles, skis, tennis rackets, golf clubs, and / or training weights.

[0014] Much of this disclosure can be described in the context of the ring wearable device 104. Therefore, the terms “ring 104,” “wearable device 104,” and similar terms may be used interchangeably unless otherwise specified herein. However, since embodiments of this disclosure are intended to be performed using other wearable devices (e.g., watch wearable devices, necklace wearable devices, bracelet wearable devices, earring wearable devices, anklet wearable devices, etc.), the use of the term “ring 104” should not be considered limiting.

[0015] In some embodiments, user device 106 may include handheld mobile computing devices such as smartphones and tablet computing devices. User device 106 may also include personal computers such as laptops and desktop computing devices. Other exemplary user device 106 may include server computing devices that can communicate with other electronic devices (e.g., via the Internet). In some implementations, computing devices may include medical devices such as external wearable computing devices (e.g., Holter monitors). Medical devices may also include implantable medical devices such as pacemakers and electrodefibrillators. Other exemplary user device 106 may include home computing devices such as Internet of Things (IoT) devices (e.g., IoT devices), smart TVs, smart speakers, smart displays (e.g., video call displays), hubs (e.g., wireless communication hubs), security systems, smart appliances (e.g., thermostats and refrigerators), and fitness equipment.

[0016] Some electronic devices (e.g., wearable device 104, user device 106) may measure physiological parameters of each user 102, such as photoplethysmography waveforms, continuous skin temperature, pulse waveforms, respiratory rate, heart rate, heart rate variability (HRV), actigraphy, electrodermal response, pulse oximetry, and / or other physiological parameters. Some electronic devices that measure physiological parameters may also perform some / all of the calculations described herein. Some electronic devices may not measure physiological parameters but may perform some / all of the calculations described herein. For example, a ring (e.g., wearable device 104), a mobile device application, or a server computing device may process received physiological data measured by other devices.

[0017] In some implementations, user 102 may operate or be associated with multiple electronic devices that measure physiological parameters and process the measured physiological parameters. In some implementations, user 102 may have a ring (e.g., wearable device 104) that measures physiological parameters. User 102 may also have or be associated with a user device 106 (e.g., a mobile device, a smartphone), and wearable device 104 and user device 106 are communicatively coupled to each other. In some cases, user device 106 may receive data from wearable device 104 and perform some / all of the calculations described herein. In some implementations, user device 106 may also measure physiological parameters described herein, such as movement / activity parameters.

[0018] For example, as shown in FIG. 1, a first user 102-a (User 1) may operate or be associated with a wearable device 104-a (e.g., a ring 104-a) and a user device 106-a that can operate as described herein. In this example, the user device 106-a associated with the user 102-a can process / store physiological parameters measured by the ring 104-a. In comparison, a second user 102-b (User 2) may be associated with a ring 104-b, a watch wearable device 104-c (e.g., a watch 104-c), and a user device 106-b, and the user device 106-b associated with the user 102-b can process / store physiological parameters measured by the ring 104-b and / or the watch 104-c. Further, an nth user 102-n (User N) may be associated with an arrangement of electronic devices described herein (e.g., a ring 104-n, a user device 106-n). In some aspects, the wearable devices 104 (e.g., a ring 104, a wristwatch 104) and other electronic devices may be communicatively coupled to the user devices 106 of their respective users 102 via Bluetooth®, Wi-Fi, and other wireless protocols.

[0019] In some implementations, the ring 104 of system 100 (e.g., wearable device 104) may be configured to collect physiological data from each user 102 based on arterial blood flow in the user's finger. In particular, the ring 104 may utilize one or more LEDs (e.g., red LED, green LED) that emit light on the palm side of the user's finger to collect physiological data based on arterial blood flow in the user's finger. In some embodiments, the ring 104 may use a combination of both green and red LEDs to acquire physiological data. The physiological data may include, but is not limited to, temperature data, accelerometer data (e.g., motion / exercise data), heart rate data, HRV data, blood oxygen level data, respiratory data, or any combination thereof, any physiological data known in the art.

[0020] Since red and green LEDs have been found to have distinct advantages when acquiring physiological data through different parts of the body under different conditions (e.g., light / dark, active / inactive), the use of both green and red LEDs may offer several advantages over other solutions. For example, green LEDs have been shown to perform better during exercise. Furthermore, the use of multiple LEDs (e.g., green and red LEDs) dispersed around ring 104 has been shown to perform better compared to wearable devices that utilize LEDs placed in close proximity to each other, such as within a watch wearable device. In addition, the blood vessels in the fingers (e.g., arteries, capillaries) are more accessible via LEDs than the blood vessels in the wrist. In particular, the arteries in the wrist are located in the lower part of the wrist (e.g., the palmar side of the wrist), which means that only capillaries are accessible in the upper part of the wrist (e.g., the back of the wrist), where wearable watch devices and similar devices are typically worn. Therefore, utilizing LEDs and other sensors within the ring 104 has been shown to offer superior performance compared to wearable devices worn on the wrist, as the ring 104 may have greater access to arteries (compared to capillaries), thereby yielding stronger signals and more valuable physiological data.

[0021] The electronic devices of system 100 (e.g., user device 106, wearable device 104) may be communicatively coupled to one or more servers 110 via wired or wireless communication protocols. For example, as shown in Figure 1, the electronic device (e.g., user device 106) may be communicatively coupled to one or more servers 110 via network 108. Network 108 may implement a transport control protocol such as the Internet and Internet Protocol (TCP / IP), or it may implement other network 108 protocols. The network connection between network 108 and each electronic device can facilitate the transfer of data via email, web, text messages, mail, or any other suitable form of interaction within the computer network 108. For example, in some embodiments, a ring 104-a associated with a first user 102-a may be communicatively coupled to user device 106-a, and user device 106-a is communicatively coupled to server 110 via network 108. In additional or alternative cases, the wearable device 104 (e.g., a ring 104, a wristwatch 104) may be coupled to the network 108 in a manner that allows it to communicate directly with the network 108.

[0022] System 100 can provide on-demand database services between a user device 106 and one or more servers 110. In some cases, the server 110 may receive data from the user device 106 via a network 108, and store and analyze the data. Similarly, the server 110 may provide data to the user device 106 via the network 108. In some cases, the server 110 may be located in one or more data centers. The server 110 may be used for data storage, management, and processing. In some implementations, the server 110 may provide a web-based interface to the user device 106 via a web browser.

[0023] In some embodiments, the system 100 can detect periods of time when user 102 is asleep and classify those periods into one or more sleep stages (e.g., sleep stage classification). For example, as shown in Figure 1, user 102-a may be associated with a wearable device 104-a (e.g., a ring 104-a) and a user device 106-a. In this example, the ring 104-a may collect physiological data related to user 102-a, including temperature, heart rate, HRV, respiratory rate, etc. In some embodiments, the data collected by the ring 104-a may be input to a machine learning classifier, which is configured to determine periods of time when user 102-a is asleep (or has been asleep). Furthermore, the machine learning classifier may be configured to classify the periods into different sleep stages, including wakefulness, REM sleep, light sleep (non-REM), and deep sleep (NREM). In some embodiments, the classified sleep stages may be displayed to user 102-a via the GUI of user device 106-a. The sleep stage classification may be used to provide user 102-a with feedback on the user's sleep patterns, such as recommended bedtime and recommended wake-up time. Furthermore, in some implementations, the sleep stage classification techniques described herein can be used to calculate individual user scores, such as a sleep score and a ready score.

[0024] In some embodiments, system 100 may utilize features derived from circadian rhythms to further improve physiological data acquisition, data processing procedures, and other techniques described herein. The term circadian rhythm can refer to the natural internal processes that regulate an individual's sleep-wake cycle, which repeats approximately every 24 hours. In this regard, the techniques described herein may utilize circadian rhythm adjustment models to improve physiological data acquisition, analysis, and data processing. For example, a circadian rhythm adjustment model may be input into a machine learning classifier along with physiological data collected from user 102-a via a wearable device 104-a. In this example, the circadian rhythm adjustment model may be configured to "weight" or adjust the physiological data collected through the user's natural approximately 24-hour circadian rhythm. In some embodiments, the system may initially start with a "baseline" circadian rhythm adjustment model and modify the baseline model using physiological data collected from each user 102 to generate an adjusted, personalized circadian rhythm adjustment model specific to each user 102.

[0025] In some embodiments, system 100 can utilize other biological rhythms to further improve the collection, analysis, and processing of physiological data by phase of these other rhythms. For example, if a weekly rhythm is detected within an individual's baseline data, the model may be configured to adjust the “weights” of the data by day of the week. Biological rhythms that may require adjustment to the model in this manner include: 1) hyperdiurnal rhythms (rhythms faster than one day, including sleep cycles in sleep states and periodic oscillations of less than an hour to several hours in physiological variables measured between wakefulness), 2) circadian rhythms, 3) non-endogenous daily rhythms that have been shown to be imposed in addition to circadian rhythms, such as work schedules, 4) weekly rhythms, or other artificial time periodicities that are exogenously imposed (e.g., in a hypothetical culture of a 12-day “week,” a 12-day rhythm can be used), 5) multi-day ovarian rhythms in women and spermatogenesis rhythms in men, 6) lunar rhythms (associated with individuals living in environments with little or no artificial light), and 7) seasonal rhythms.

[0026] Biological rhythms are not always stationary. For example, many women experience variability in ovarian cycle length throughout their cycles, and hyperquaternary rhythms are not expected to occur at exactly the same time or with the same periodicity across days, even within a single user. Therefore, the detection of these rhythms can be improved by using signal processing techniques sufficient to quantify the frequency components while maintaining the temporal resolution of these rhythms in physiological data, assigning the phase of each rhythm to each measured moment, thereby correcting the adjustment model and time interval comparison. Biological rhythm adjustment models and parameters may be added, in a combination of linear or nonlinear approaches, as needed, to more accurately capture the dynamic physiological baseline of an individual or group of individuals.

[0027] In some embodiments, each device of system 100 may support a technique for selecting an optical sensor from a set of optical sensors on a wearable electronic device. In particular, system 100 shown in Figure 1 may support a technique that allows the wearable device to change the set of sensors used to measure data associated with user 102-a. The wearable device may change the set of sensors based on one or more metrics such as signal quality, signal strength, temperature, motion, and time.

[0028] For example, a wearable device such as ring 104-a may activate a first combination of optical sensors. The first combination of optical sensors may include a set of transmitter sensors from a plurality of transmitter sensors of the wearable electronic device and a set of receiver sensors from a plurality of receiver sensors. In some cases, the plurality of transmitter sensors may include at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength. In some implementations, at least one optical sensor of the first combination of optical sensors may be located under a protrusion on the inner surface of the wearable electronic device. The wearable device may measure one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time and determine a signal quality metric associated with one or more signals. Based on the signal quality metric, the wearable device may select a second combination of optical sensors for use at a second time.

[0029] In some cases, ring 104-a may determine heart rate data based on PPG monitoring. Optical sensor selection and PPG monitoring may be performed by any of the components of system 100, including ring 104-a, user device 106-a associated with user 1, one or more servers 110, or any combination thereof. Once heart rate data is determined, system 100 may selectively display all or a subset of the heart rate data on the GUI of user device 106-a.

[0030] Those skilled in the art will understand that one or more aspects of this disclosure may be implemented in System 100 to solve problems other than those described above, either additionally or as alternatives. Furthermore, aspects of this disclosure may provide technical improvements to “conventional” systems or processes as described herein. However, this specification and the accompanying drawings only include illustrative technical improvements resulting from carrying out aspects of this disclosure and do not represent all of the technical improvements provided in the claims.

[0031] Figure 2 shows an example of a system 200 supporting a configurable PPG system according to aspects of this disclosure. System 200 may implement or be implemented by system 100. In particular, system 200 shows examples of a ring 104 (e.g., a wearable device 104), a user device 106, and a server 110, as described with reference to Figure 1.

[0032] In some embodiments, the ring 104 may be configured to be worn around a user's finger and may determine one or more user physiological parameters when worn around the user's finger. Exemplary measurements and determinations may include, but are not limited to, the user's skin temperature, pulse waveform, respiratory rate, heart rate, HRV, blood oxygen level, etc.

[0033] The system 200 further includes a user device 106 (e.g., a smartphone) that communicates with the ring 104. For example, the ring 104 may communicate with the user device 106 wirelessly and / or via a wired connection. In some implementations, the ring 104 may transmit measured and processed data (e.g., temperature data, PPG data, motion / accelerometer data, ring input data, etc.) to the user device 106. The user device 106 may also transmit data to the ring 104, such as firmware / configuration updates for the ring 104. The user device 106 may process the data. In some implementations, the user device 106 may transmit the data to the server 110 for processing and / or storage.

[0034] The ring 104 may include a housing 205 which may include an inner housing 205-a and an outer housing 205-b. In some embodiments, the housing 205 of the ring 104 may house, or otherwise contain, various components of the ring, including, but not limited to, device electronics, a power supply (e.g., a battery 210, and / or capacitors), one or more substrates (e.g., a printable circuit board) interconnecting the device electronics and / or power supply. The device electronics may include device modules (e.g., hardware / software) such as a processing module 230-a, a memory 215, a communication module 220-a, and a power module 225. The device electronics may also include one or more sensors. Exemplary sensors may include one or more temperature sensors 240, a PPG sensor assembly (e.g., a PPG system 235), and one or more motion sensors 245.

[0035] The sensors may include associated modules (not shown) configured to communicate with each component / module of the ring 104 and generate signals associated with each sensor. In some embodiments, each component / module of the ring 104 may be coupled to communicate with one another via wired or wireless connections. Furthermore, the ring 104 may include additional and / or alternative sensors or other components configured to collect physiological data from the user, including light sensors (e.g., LEDs), oximeters, and the like.

[0036] The ring 104 shown and described with reference to Figure 2 is provided for illustrative purposes only. Therefore, the ring 104 may include additional or alternative components, such as those shown in Figure 2. Other rings 104 providing the functions described herein may be manufactured. For example, a ring 104 with fewer components (e.g., sensors) may be manufactured. In a particular example, a ring 104 may be manufactured having a single temperature sensor 240 (or other sensor), a power supply, and device electronics configured to read the single temperature sensor 240 (or other sensor). In another particular example, the temperature sensor 240 (or other sensor) may be attached to the user's finger (e.g., using a clamp, spring-loaded clamp, etc.). In this case, the sensor may be wired to another computing device, such as a wrist-worn computing device, that reads the temperature sensor 240 (or other sensor). In other examples, a ring 104 including additional sensors and processing functions may be manufactured.

[0037] The housing 205 may include one or more components of the housing 205. The housing 205 may include an outer housing 205-b component (e.g., a shell) and an inner housing 205-a component (e.g., a molded part). The housing 205 may include additional components (e.g., additional layers) not explicitly shown in Figure 2. For example, in some configurations, the ring 104 may include one or more insulating layers that electrically insulate the device electronics and other conductive materials (e.g., electrical traces) from the outer housing 205-b (e.g., a metal outer housing 205-b). The housing 205 may provide structural support for the device electronics, battery 210, substrate(s), and other components. For example, the housing 205 may protect the device electronics, battery 210, and substrate(s) from mechanical forces such as pressure and shock. The housing 205 may also protect the device electronics, battery 210, and substrate(s) from water and / or other chemicals.

[0038] The outer housing 205-b may be manufactured from one or more materials. In some implementations, the outer housing 205-b may include a metal such as titanium, which can provide strength and wear resistance with a relatively light weight. The outer housing 205-b may also be manufactured from other materials such as polymers. In some implementations, the outer housing 205-b may be both protective and decorative.

[0039] The inner housing 205-a may be configured to interface with the user's finger. The inner housing 205-a may be formed from a polymer (e.g., a medical-grade polymer) or other material. In some implementations, the inner housing 205-a may be transparent. For example, the inner housing 205-a may be transparent to light emitted by a PPG light-emitting diode (LED). In some implementations, the inner housing 205-a components may be molded onto the outer housing 205-b. For example, the inner housing 205-a may include a polymer molded (e.g., injection-molded) to fit into the metal shell of the outer housing 205-b.

[0040] The ring 104 may include one or more substrates (not shown). The device electronics and battery 210 may be contained on one or more substrates. For example, the device electronics and battery 210 may be mounted on one or more substrates. Exemplary substrates may include one or more printed circuit boards (PCBs), such as flexible PCBs (e.g., polyimide). In some mounting configurations, the electronics / battery 210 may include surface mount devices (e.g., surface mount technology (SMT) devices) on the flexible PCB. In some mounting configurations, one or more substrates (e.g., one or more flexible PCBs) may include electrical traces that provide electrical communication between the device electronics. The electrical traces may also connect the battery 210 to the device electronics.

[0041] The device electronics, battery 210, and substrate may be arranged within the ring 104 in various ways. In some configurations, one substrate containing the device electronics may be mounted along the bottom (e.g., lower half) of the ring 104 so that sensors (e.g., PPG system 235, temperature sensor 240, motion sensor 245, and other sensors) interface with the underside of the user's fingers. In these configurations, the battery 210 may be included along the top of the ring 104 (e.g., on another substrate).

[0042] The various components / modules of ring 104 represent functions that may be included in ring 104 (e.g., circuits and other components). A module may include any discrete and / or integrated electronic circuit components that implement analog and / or digital circuits that can generate the functions belonging to the module herein. For example, a module may include analog circuits (e.g., amplifiers, filtering circuits, analog-to-digital converters, and / or other signal conditioning circuits). A module may also include digital circuits (e.g., combinational logic circuits or sequential logic circuits, memory circuits, etc.).

[0043] The memory 215 (memory module) of ring 104 may include any volatile, non-volatile, magnetic, or electrical medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other memory device. The memory 215 may store any of the data described herein. For example, the memory 215 may be configured to store data collected by the respective sensors and PPG system 235 (e.g., motion data, temperature data, PPG data). Furthermore, the memory 215 may include instructions that, when executed by one or more processing circuits, cause the module to perform various functions attributed to the module herein. The device electronics of ring 104 described herein are merely illustrative device electronics. Therefore, the types of electronic components used to implement the device electronics may vary based on design considerations.

[0044] The functions resulting from the modules of ring 104 described herein may be embodied as one or more processors, hardware, firmware, software, or any combination thereof. The descriptions of different characteristics as modules are intended to highlight different functional aspects and do not necessarily mean that such modules must be implemented by separate hardware / software components. Rather, the functions associated with one or more modules may be performed by separate hardware / software components or integrated within a common hardware / software component.

[0045] The processing module 230-a of ring 104 may include one or more processors (e.g., processing units), microcontrollers, digital signal processors, system-on-a-chip (SoC), and / or other processing devices. The processing module 230-a communicates with modules included in ring 104. For example, the processing module 230-a may send / receive data to / from other components of ring 104, such as modules and sensors. As described herein, modules may be implemented by various circuit components. Thus, modules may also be called circuits (e.g., communication circuits and power circuits).

[0046] The processing module 230-a may communicate with the memory 215. The memory 215 may contain computer-readable instructions that, when executed by the processing module 230-a, cause the processing module 230-a to perform various functions attributed to the processing module 230-a as described herein. In some implementations, the processing module 230-a (e.g., a microcontroller) may include additional features related to other modules, such as communication functions provided by the communication module 220-a (e.g., an integrated Bluetooth® Low Energy transceiver) and / or additional onboard memory 215.

[0047] The communication module 220-a may include circuitry that provides wireless and / or wired communication with the user device 106 (for example, the communication module 220-b of the user device 106). In some implementations, the communication modules 220-a and 220-b may include wireless communication circuits such as Bluetooth® circuitry and / or Wi-Fi circuitry. In some implementations, the communication modules 220-a and 220-b may include wired communication circuits such as Universal Serial Bus (USB) communication circuitry. Using the communication module 220-a, the ring 104 and the user device 106 may be configured to communicate with each other. The ring's processing module 230-a may be configured to send / receive data to and from the user device 106 via the communication module 220-a. Illustrative data may include, but is not limited to, motion data, temperature data, pulse waveforms, heart rate data, HRV data, PPG data, and status updates (e.g., charge status, battery charge level, and / or ring 104 configuration settings). The ring processing module 230-a may also be configured to receive updates (e.g., software / firmware updates) and data from the user device 106.

[0048] The ring 104 may include a battery 210 (e.g., a rechargeable battery 210). An exemplary battery 210 may include a lithium-ion or lithium-polymer type battery 210, but a variety of battery 210 options are possible. The battery 210 may be wirelessly charged. In some implementations, the ring 104 may include a power source other than the battery 210, such as a capacitor. The power source (e.g., the battery 210 or capacitor) may have a curved geometric shape that matches the curve of the ring 104. In some embodiments, the charger or other power source may include additional sensors that can be used to collect data in addition to, or supplementing, the data collected by the ring 104 itself. Furthermore, the charger or other power source for the ring 104 may function as a user device 106, in which case the charger or other power source for the ring 104 may be configured to receive data from the ring 104, store and / or process the data received from the ring 104, and communicate data between the ring 104 and the server 110.

[0049] In some embodiments, the ring 104 includes a power module 225 that can control the charging of the battery 210. For example, the power module 225 may interface with an external wireless charger that charges the battery 210 when interfaced with the ring 104. The charger may include a datum structure that mates with the datum structure of the ring 104 to produce a specific orientation with the ring 104 during charging. The power module 225 may also regulate the voltage of the device electronics, regulate the power output to the device electronics, and monitor the charge state of the battery 210. In some embodiments, the battery 210 may include a protection circuit module (PCM) that protects the battery 210 from high-current discharge, overvoltage during charging, and undervoltage during discharging. The power module 225 may also include electrostatic discharge (ESD) protection.

[0050] One or more temperature sensors 240 may be electrically coupled to the processing module 230-a. The temperature sensors 240 may be configured to generate a temperature signal (e.g., temperature data) indicating the temperature read or sensed by the temperature sensors 240. The processing module 230-a may determine the user's temperature at the location of the temperature sensors 240. For example, in the ring 104, the temperature data generated by the temperature sensors 240 may indicate the user's temperature (e.g., skin temperature) on the user's finger. In some implementations, the temperature sensors 240 may be in contact with the user's skin. In other implementations, a portion of the housing 205 (e.g., the inner housing 205-a) may form a barrier (e.g., a thin thermally conductive barrier) between the temperature sensors 240 and the user's skin. In some implementations, the portion of the ring 104 configured to contact the user's finger may have a thermally conductive portion and an insulating portion. The thermally conductive portion can conduct heat from the user's finger to the temperature sensors 240. The insulating portion can insulate the ring 104 (for example, the temperature sensor 240) from the ambient temperature.

[0051] In some implementations, the temperature sensor 240 may generate a digital signal (e.g., temperature data) that the processing module 230-a can use to determine the temperature. As another example, if the temperature sensor 240 includes a passive sensor, the processing module 230-a (or the temperature sensor 240 module) may measure the current / voltage generated by the temperature sensor 240 and determine the temperature based on the measured current / voltage. The exemplary temperature sensor 240 may include a thermistor such as a negative temperature coefficient (NTC) thermistor, or other types of sensors including resistors, transistors, diodes, and / or other electrical / electronic components.

[0052] The processing module 230-a may sample the user's temperature over time. For example, the processing module 230-a may sample the user's temperature according to a sampling rate. An exemplary sampling rate may include one sample per second, but the processing module 230-a may be configured to sample the temperature signal at other sampling rates higher or lower than one sample per second. In some implementations, the processing module 230-a may continuously sample the user's temperature throughout the day and night. Sampling at a sufficient rate throughout the day (e.g., one sample per second) can provide sufficient temperature data for the analysis described herein.

[0053] The processing module 230-a can store the sampled temperature data in memory 215. In some implementations, the processing module 230-a can process the sampled temperature data. For example, the processing module 230-a can determine the average temperature value over a certain period of time. In one example, the processing module 230-a can determine the average temperature value per minute by summing all the temperature values ​​collected over one minute and dividing by the number of samples over one minute. In a particular example where the temperature is sampled at one sample per second, the average temperature might be the sum of all sampled temperatures for one minute divided by 60 seconds. Memory 215 can store average temperature values ​​over time. In some implementations, memory 215 may store average temperatures (e.g., one per minute) instead of sampled temperatures to conserve memory.

[0054] The sampling rate may be stored in memory 215 and may be configurable. In some implementations, the sampling rate may be the same throughout the day and night. In other implementations, the sampling rate may vary throughout the day / night. In some implementations, ring 104 may filter / reject temperature readings such as large temperature spikes that do not indicate physiological changes (e.g., temperature spikes from a hot shower). In some implementations, ring 104 may filter / reject temperature readings that may be unreliable due to other factors such as excessive movement during exercise (e.g., as indicated by motion sensor 245).

[0055] Ring 104 (e.g., a communication module) may transmit the sampled and / or averaged temperature data to the user device 106 for storage and / or further processing. The user device 106 may transfer the sampled and / or averaged temperature data to the server 110 for storage and / or further processing.

[0056] Although the ring 104 is shown as containing a single temperature sensor 240, the ring 104 may contain multiple temperature sensors 240 at one or more locations, such as along the inner housing 205-a near the user's finger. In some implementations, the temperature sensor 240 may be a standalone temperature sensor 240. Additionally or alternatively, one or more temperature sensors 240 may be included with other components such as an accelerometer and / or a processor (for example, they may be packaged together with the other components).

[0057] The processing module 230-a may acquire and process data from multiple temperature sensors 240 in a similar manner to that described for a single temperature sensor 240. For example, the processing module 230 may individually sample, average, and store temperature data from each of the multiple temperature sensors 240. In other examples, the processing module 230-a may sample the sensors at different rates and average / store different values ​​for different sensors. In some implementations, the processing module 230-a may be configured to determine a single temperature based on the average of two or more temperatures determined by two or more temperature sensors 240 at different locations on a finger.

[0058] A temperature sensor 240 on the ring 104 may acquire distal temperature at the user's finger (e.g., any finger). For example, one or more temperature sensors 240 on the ring 104 may acquire the user's temperature from the underside of the finger or at different locations on the finger. In some embodiments, the ring 104 can acquire distal temperature continuously (e.g., at a certain sampling rate). While distal temperature measured by the ring 104 at the finger is described herein, other devices may measure temperature at the same / different locations. In some cases, distal temperature measured at the user's finger may differ from temperature measured at the user's wrist or other external body location. Furthermore, distal temperature measured at the user's finger (e.g., "shell" temperature) may differ from the user's core temperature. Thus, the ring 104 can provide a useful temperature signal that may not be acquired at other internal / external locations of the body. In some cases, continuous temperature measurement at the finger may capture temperature fluctuations (e.g., small or large fluctuations) that may not be apparent in core body temperature. For example, continuous temperature measurement on the finger can capture minute- or hourly temperature fluctuations, providing additional insights that may not be provided by other temperature measurements on other parts of the body.

[0059] The ring 104 may include a PPG system 235. The PPG system 235 may include one or more light transmitters that transmit light. The PPG system 235 may also include one or more light receivers that receive light transmitted by one or more light transmitters. The light receivers may generate a signal (hereinafter, "PPG" signal) indicating the amount of light received by the light receivers. The light transmitters can illuminate an area of ​​the user's fingers. The PPG signal generated by the PPG system 235 may indicate blood perfusion in the irradiated area. For example, the PPG signal may indicate a change in blood volume in the irradiated area caused by the user's pulse pressure. The processing module 230-a may sample the PPG signal and determine the user's pulse waveform based on the PPG signal. The processing module 230-a may determine various physiological parameters based on the user's pulse waveform, such as the user's respiratory rate, heart rate, HRV, blood oxygen saturation, and other circulatory parameters.

[0060] In some implementations, the PPG system 235 may be configured as a reflective PPG system 235 in which the optical receiver receives transmitted light reflected through the user's finger area. In some implementations, the PPG system 235 may be configured as a transmissive PPG system 235 in which the optical transmitter and optical receiver are positioned opposite each other so that light is transmitted directly to the optical receiver through a portion of the user's finger.

[0061] The number and ratio of transmitters and receivers included in the PPG system 235 may vary. An exemplary optical transmitter may include a light-emitting diode (LED). The optical transmitter can transmit light in the infrared spectrum and / or other spectra. An exemplary optical receiver may include, but is not limited to, an optical sensor, a phototransistor, and a photodiode. The optical receiver may be configured to generate a PPG signal in response to the wavelength received from the optical transmitter. The positions of the transmitters and receivers may vary. In addition, a single device may include reflective and / or transmissive PPG systems 235.

[0062] The PPG system 235 shown in Figure 2 may include a reflective PPG system 235 in some implementations. In these implementations, the PPG system 235 may include a centrally located optical receiver (for example, at the bottom of the ring 104) and two optical transmitters located on each side of the optical receiver. In this implementation, the PPG system 235 (for example, the optical receiver) may generate a PPG signal based on light received from one or both of the optical transmitters. Other implementations may involve other arrangements, combinations, and / or configurations of one or more optical transmitters and / or optical receivers.

[0063] The processing module 230-a can control one or both of the optical transmitters to transmit light while sampling the PPG signal generated by the optical receiver. In some implementations, the processing module 230-a can cause the optical transmitter with a stronger received signal to transmit light while sampling the PPG signal generated by the optical receiver. For example, the selected optical transmitter may transmit light when the PPG signal has a sampling rate (e.g., 250 It can continuously emit light while being sampled at Hz.

[0064] Sampling the PPG signal generated by the PPG system 235 may result in a pulse waveform that may be called a "PPG". The pulse waveform may represent blood pressure versus time for multiple cardiac cycles. The pulse waveform may include peaks that indicate cardiac cycles. Furthermore, the pulse waveform may include respiratory-induced fluctuations that can be used to determine the respiratory rate. In some implementations, the processing module 230-a may store the pulse waveform in memory 215. The processing module 230-a may process the pulse waveform as it was generated and / or from memory 215 to determine the user's physiological parameters as described herein.

[0065] The processing module 230-a may determine the user's heart rate based on the pulse waveform. For example, the processing module 230-a may determine the heart rate (for example, in beats per minute) based on the time between peaks in the pulse waveform. The time between peaks is sometimes called the pulse interval (IBI). The processing module 230-a may store the determined heart rate value and IBI value in the memory 215.

[0066] The processing module 230-a can determine HRV over time. For example, the processing module 230-a can determine HRV based on fluctuations in IBls. The processing module 230-a can store the HRV values ​​over time in memory 215. Furthermore, the processing module 230-a can determine the user's respiratory rate over time. For example, the processing module 230-a can determine the respiratory rate based on frequency modulation, amplitude modulation, or baseline modulation of the user's IBI value over a period of time. The respiratory rate may be calculated as respiratory rate per minute or as another respiratory rate (e.g., respiratory rate per 30 seconds). The processing module 230-a can store the user's respiratory rate values ​​over time in memory 215.

[0067] The ring 104 may include one or more motion sensors 245, such as one or more accelerometers (e.g., 6D accelerometers) and / or one or more gyroscopes (gyro). The motion sensors 245 may generate motion signals indicating the movement of the sensors. For example, the ring 104 may include one or more accelerometers that generate acceleration signals indicating the acceleration of the accelerometers. As another example, the ring 104 may include one or more gyro sensors that generate gyro signals indicating angular motion (e.g., angular velocity) and / or changes in orientation. The motion sensors 245 may be included in one or more sensor packages. An example of an accelerometer / gyro sensor is the Bosch BM 1 160 inertial microelectromechanical system (MEMS) sensor, which can measure angular velocity and acceleration in three orthogonal axes.

[0068] The processing module 230-a may sample motion signals at a sampling rate (e.g., 50 Hz) and determine the motion of the ring 104 based on the sampled motion signals. For example, the processing module 230-a may sample acceleration signals to determine the acceleration of the ring 104. As another example, the processing module 230-a may sample gyro signals to determine angular motion. In some implementations, the processing module 230-a may store motion data in memory 215. The motion data may include sampled motion data, as well as motion data calculated based on the sampled motion signals (e.g., acceleration values ​​and angular values).

[0069] Ring 104 can store various types of data as described herein. For example, ring 104 can store temperature data such as raw sampled temperature data and calculated temperature data (e.g., mean temperature). As another example, ring 104 may store PPG signal data such as pulse waveforms and data calculated based on the pulse waveforms (e.g., heart rate values, IBI values, HRV values, and respiratory values). Ring 104 can also store motion data such as sampled motion data showing linear and angular motion.

[0070] The ring 104 or other computing device may calculate and store additional values ​​based on sampled / calculated physiological data. For example, the processing module 230 may calculate and store various metrics such as sleep metrics (e.g., sleep score), activity metrics, and ready-to-go metrics. The ring 104 or other computing / wearable device may calculate various values / metrics related to movement. Exemplary derived values ​​for movement data may include, but are not limited to, motion count values, regularity values, intensity values, metabolic equivalents (METs) of task values, and orientation values. Motion count, regularity values, intensity values, and METs may indicate the amount of user motion over time (e.g., velocity / acceleration). Orientation values ​​may indicate how the ring 104 is oriented on the user's finger and whether the ring 104 is worn on the left or right hand.

[0071] In some implementations, motion counts and regularity values ​​may be determined by counting the number of acceleration peaks within one or more time periods (e.g., one or more periods of 30 seconds to 1 minute). Intensity values ​​may indicate the number of motions and the associated intensity of the motions (e.g., acceleration values). Intensity values ​​may be classified as low, medium, and high depending on the associated threshold acceleration value. MET may be determined based on the intensity of motions during a period (e.g., 30 seconds), the regularity / irregularity of the motions, and the number of motions associated with different intensities.

[0072] In some implementations, the processing module 230-a may compress the data stored in memory 215. For example, the processing module 230-a may delete sampled data after performing calculations based on it. As another example, the processing module 230-a may average the data over a longer time period to reduce the number of stored values. In a particular example, if the user's average temperature over one minute is stored in memory 215, the processing module 230-a may calculate the average temperature over a five-minute period for storage, and then erase the average temperature data for the one minute. The processing module 230-a may compress the data based on various factors such as the total amount of memory 215 used / available and / or the elapsed time since ring 104 last sent data to the user device 106.

[0073] The user's physiological parameters may be measured by sensors included on the ring 104, but other devices may also measure the user's physiological parameters. For example, the user's body temperature may be measured by a temperature sensor 240 included on the ring 104, but other devices may also measure the user's body temperature. In some examples, other wearable devices (e.g., wrist devices) may include sensors for measuring the user's physiological parameters. In addition, medical devices such as external medical devices (e.g., wearable medical devices) and / or implantable medical devices can measure the user's physiological parameters. One or more sensors on any type of computing device may be used to implement the techniques described herein.

[0074] Physiological measurements may be performed continuously throughout the day and / or night. In some implementations, physiological measurements may be performed between the daytime 104 portion and / or the nighttime portion. In some implementations, physiological measurements may be performed in response to determining that the user is in a particular state, such as an active state, a resting state, and / or a sleeping state. For example, the ring 104 may perform physiological measurements in the resting / sleeping state to obtain a cleaner physiological signal. In one example, the ring 104 or other device / system may detect when the user is resting and / or sleeping and obtain physiological parameters (e.g., temperature) for the detected state. The device / system may use the resting / sleeping physiological data and / or other data when the user is in other states in order to implement the technology of this disclosure.

[0075] In some implementations, as previously described herein, the ring 104 may be configured to collect, store, and / or process data, and may transfer any of the data described herein to the user device 106 for storage and / or processing. In some embodiments, the user device 106 includes a wearable application 250, an operating system (OS) 285, a web browser application (e.g., a web browser 280), one or more additional applications, and a GUI 275. The user device 106 may further include other modules and components, including sensors, audio devices, haptic feedback devices, etc. The wearable application 250 may include examples of applications (e.g., “Apps”) that can be installed on the user device 106. The wearable application 250 may be configured to take data from the ring 104, store the acquired data, and process the acquired data as described herein. For example, a wearable application 250 may include a user interface (UI) module 255, an acquisition module 260, a processing module 230-b, a communication module 220-b, and a storage module (e.g., a database 265) configured to store application data.

[0076] The various data processing operations described herein may be performed by the ring 104, the user device 106, the server 110, or any combination thereof. For example, in some cases, data collected by the ring 104 may be preprocessed and sent to the user device 106. In this example, the user device 106 may perform some data processing operations on the received data, send the data to the server 110 for data processing, or both. For example, in some cases, the user device 106 may perform processing operations that require relatively low processing power and / or operations that require relatively low latency, while the user device 106 may send data to the server 110 for processing operations that require relatively high processing power and / or operations that allow for relatively high latency.

[0077] In some embodiments, the ring 104, user device 106, and server 110 of system 200 may be configured to evaluate the user's sleep patterns. In particular, each component of system 200 may be used to collect data from the user via the ring 104 and to generate one or more scores for the user (e.g., sleep score, readiness score) based on the collected data. For example, as previously stated herein, the ring 104 of system 200 may be worn by the user to collect data from the user, including temperature, heart rate, HRV, etc. The data collected by the ring 104 may be used to evaluate the user's sleep for a given "sleep day" and to determine when the user is sleeping. In some embodiments, the user's score may be calculated for each sleep day such that a first sleep day is associated with a first set of scores, and a second sleep day is associated with a second set of scores. The scores may be calculated for each sleep day based on the data collected by the ring 104 during each sleep day. The scores may include, but are not limited to, a sleep score, readiness score, etc.

[0078] In some cases, a “sleep day” may be aligned with the conventional calendar day, such that a given sleep day lasts from midnight to midnight on each calendar day. In other cases, a sleep day may be offset relative to the calendar day. For example, a sleep day could last from 6:00 p.m. (18:00) on one calendar day to 6:00 p.m. (18:00) on the next calendar day. In this example, 6:00 p.m. may act as a “cutoff time,” where data collected from the user before 6:00 p.m. is counted for the current sleep day, and data collected from the user after 6:00 p.m. is counted for the subsequent sleep day. Due to the fact that most individuals sleep most at night, offsetting sleep days relative to the calendar day may allow system 200 to evaluate the user’s sleep pattern in a way that matches the user’s sleep schedule. In some cases, the user may be able to selectively adjust the timing of sleep days relative to the calendar day (e.g., via a GUI) so that the sleep days are aligned with the duration of sleep each user typically sleeps.

[0079] For example, a user's overall sleep score may be calculated based on a set of contributing factors including total sleep, efficiency, rest, REM sleep, deep sleep, latency, timing, or any combination thereof. The sleep score may include any contributing factors. The “Total Sleep” contributing factor may refer to the sum of all sleep periods in a sleep day. The “Efficiency” contributing factor may reflect the proportion of time spent sleeping compared to time spent awake while in bed, and may be calculated using the efficiency average of the longer sleep periods in a sleep day (e.g., primary sleep period), weighted by the duration of each sleep period. The “Rest” contributing factor can indicate how restful the user's sleep is, and may be calculated using the average of all sleep periods in a sleep day, weighted by the duration of each period. Rest contributing factors may be based on “Awakening Counts” (e.g., the sum of all awakenings detected (when the user was awake) in different sleep periods), excessive movement, and “Get-Up Counts” (e.g., the sum of all get-ups detected (when the user got out of bed) in different sleep periods).

[0080] The "REM sleep" contributor may refer to the sum of REM sleep durations across all sleep periods in a sleep day that include REM sleep. Similarly, the "deep sleep" contributor may refer to the sum of deep sleep durations across all sleep periods in a sleep day that include deep sleep. The "latency" contributor may indicate how long it takes a user to fall asleep (e.g., mean, median, longest), and may be calculated using the average of the longest sleep periods across the entire sleep day, weighted by the duration of each period and the number of such periods (e.g., the aggregation of a given sleep stage(s) may be a contributor by itself or weight other contributors). Finally, the "timing" contributor may refer to the relative timing of sleep periods within a sleep day and / or calendar day, and may be calculated using the average of all sleep periods in a sleep day, weighted by the duration of each period.

[0081] As another example, a user's overall readiness score may be calculated based on a set of contributors, including sleep, sleep balance, heart rate, HRV balance, recovery index, body temperature, activity, activity balance, or any combination thereof. The readiness score may include any number of contributors. The “sleep” contributor may refer to the combined sleep score of all sleep periods within a sleep day. The “sleep balance” contributor may refer to the cumulative duration of all sleep periods within a sleep day. In particular, sleep balance may indicate to the user whether the sleep they have had over a certain period (e.g., the past two weeks) is balanced with their needs. Typically, adults need 7-9 hours of sleep at night to be healthy, alert, and in the best mental and physical condition for activity. However, it is normal to have poor sleep on some nights, and therefore, the sleep balance contributor takes long-term sleep patterns into account to determine whether each user's sleep needs are being met. The “resting heart rate” contributing factor may represent the lowest heart rate from the longest sleep period of a sleep day (e.g., the primary sleep period), and / or the lowest heart rate from a nap that occurs after the primary sleep period.

[0082] Continuing to refer to the “contributors” (e.g., factors, contributing factors) of the readiness score, the “HRV balance” contributor may represent the peak HRV mean from the primary sleep period and naps occurring after the primary sleep period. The HRV balance contributor can help users track their recovery status by comparing the user’s HRV trend over a first period (e.g., two weeks) to the average HRV over a second, longer period (e.g., three months). The “recovery index” contributor may be calculated based on the longest sleep period. The recovery index measures how long it takes for the user’s resting heart rate to stabilize at night. A sign of very good recovery is that the user’s resting heart rate stabilizes during the first half of the night, at least six hours before the user wakes up, leaving body time to recover the next day. The “body temperature” contributor may be calculated based on the longest sleep period (e.g., primary sleep period) or based on naps occurring after the longest sleep period if the user’s peak temperature during the nap is at least 0.5°C higher than the peak temperature during the longest sleep period. In some embodiments, the ring can measure the user's body temperature while the user is sleeping, and the system 200 can display the user's average temperature relative to the user's baseline temperature. If the user's body temperature is outside those normal ranges (e.g., obviously above or below 0.0), the body temperature contributing factor may be highlighted (e.g., proceed to a “pay attention” state) or otherwise generate a warning to the user.

[0083] In some embodiments, system 200 may support techniques for selecting an optical sensor from a set of optical sensors in a wearable electronic device. The wearable device may change (e.g., dynamically switch) the set of sensors based on one or more metrics such as signal quality, signal strength, temperature, motion, or time. Additionally or alternatively, system 200 may adjust the activation of optical transmitters, the activation of optical receivers, or other parameters related to both. For example, system 200 may adjust the sampling rate of one or more optical receivers based on signal quality, which can improve battery life when the measured signal quality is relatively good. In some examples, system 200 may adjust the power of an optical transmitter based on signal quality or a similar quality metric (e.g., adjusting LED lit-up time or lit-up power). In such examples, system 200 may dynamically adjust one or more measurement parameters (e.g., combination of sensors to activate, sampling rate, power output, etc.) to optimize measurement accuracy, battery life, or some other parameter. In some embodiments, the ring 104, the user device 106, the server 110 of the system 200, or any combination of these components may be configured to perform such selection and adjustment.

[0084] For example, a wearable device such as a ring 104 may activate a first combination of optical sensors, such as an optical sensor associated with the PPG system 235. The first combination of optical sensors may include a set of transmitter sensors (e.g., LEDs) from a plurality of transmitter sensors of the wearable electronic device and a set of receiver sensors (e.g., photodetectors) from a plurality of receiver sensors. In some cases, the plurality of transmitter sensors may include at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength. In some implementations, at least one optical sensor of the first combination of optical sensors may be located under a projection (e.g., a dome or raised surface) on the inner surface of the wearable electronic device. The wearable device may, at a first time, measure one or more signals from the set of transmitter sensors in the set of receiver sensors and determine a signal quality metric associated with one or more signals. Based on the signal quality metric, the wearable device may select a second combination of optical sensors for use at a second time. Additionally or alternatively, a wearable device may adjust one or more measurement parameters based on signal quality metrics.

[0085] In some cases, the ring 104 may determine heart rate data based on PPG monitoring. Optical sensor selection and PPG monitoring may be performed by any of the components of the system 200, including the ring 104, the user device 106, one or more servers 110, or any combination thereof.

[0086] Figure 3 shows an example of a wearable electronic device 300 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 300 may implement system 100, system 200, or both, or be implemented by them. In particular, the wearable electronic device 300 shows an example of a ring 104 (e.g., wearable device 104) as described with reference to Figures 1 and 2. The wearable electronic device 300 may include one or more green LEDs 302 at different locations on the wearable electronic device 300. In Figure 3, the wearable electronic device 300 has two green LEDs 302 (e.g., LEDs) located between IR LED 304-a and red LED 304-b It may include 302-a (LED 302-b) and photodiodes 306-a, 306-b (e.g., photodetector, photoreceiver). In some implementations, the first green LED 302-a (green LED 1) can be placed between the first photodiode 306-a (photodiode 1) and the IR / red LEDs 304-a and 304-b. In some implementations, the second green LED 302-b (green LED 2) can be placed between the second photodiode 306-b (photodiode 2) and the IR / red LED 304-b.

[0087] In Figure 3, the two green LEDs 302-a and 302-b are located below the circular portion of the inner housing 308 of the wearable electronic device 300, between the protrusions of the circular portion of the inner housing 308 of the wearable electronic device 300. The wearable electronic device 300 may also include an outer housing 312. The position and layout of the LEDs and photodetectors may be configured to improve specific measurements. For example, green LED 302-b (green LED 2) and photodiode 306-b (photodiode 2) are located below the green LED The light emitted from 302-b (green LED 2) can be positioned and angled so that it can be easily captured by photodiode 306-b (photodiode 2) after being reflected from the finger of the user wearing the wearable electronic device 300. Similarly, the green LED Light emitted from 302-a (green LED 1) can be captured by photodiode 306-a (photodiode 1). As described herein, the wearable electronic device 300 may select from among different combinations of LEDs and photodetectors based on a signal quality metric. For example, the wearable electronic device 300 may select a combination including green LED 302-a (green LED 1) and photodiode 306-a (photodiode 1) for a measurement in a first time, and then switch to a combination including green LED 302-b (green LED 2) and photodiode 306-b (photodiode 2) in a second time, based on a signal quality metric (e.g., measured signal quality).

[0088] In Figures 3 to 7, the photodiode may sample from an adjacent green LED 302 (for example, one or more of the nearest green LEDs). For example, in Figure 3, photodiode 306-a (photodiode 1) samples from a green LED A PPG signal can be generated in response to light received from 302-a (green LED 1). In another example, in Figure 3, photodiode 306-b (photodiode 2) can generate a PPG signal in response to light received from green LED 302-b (green LED 1). 2) A PPG signal can be generated in response to the light received from. In some cases, the green LED 302 may be positioned (e.g., separated) such that the transmission of green light from green LED 302-a (green LED 1) to photodiode 306-b (photodiode 2), or from green LED 302-b (green LED 2) to photodiode 306-a (photodiode 1), is minimized or eliminated. In these arrangements, photodiode 306 may be limited to detecting the adjacent green LED 302. Including multiple pairs of green LEDs and adjacent photodiodes, as shown in Figures 3 to 7, can help ensure that the green LEDs can be used for different ring orientations. For example, if the ring is rotated from its default orientation, the green LEDs and adjacent photodiodes can still receive signals from the underside of the user's finger.

[0089] In some implementations, the wearable electronic device 300 (e.g., ring 104) may be configured to use a single transmitter and a single receiver to generate a PPG signal. The exemplary transmitter-receiver pairs in Figures 3 to 7 may include 1) a green LED 1 and photodiode 1, 2) an IR LED and photodiode 1, 3) an IR LED and photodiode 2, 4) a red LED and photodiode 1, 5) a red LED and photodiode 2, and 6) a green LED 2 and photodiode 2.

[0090] In some implementations, a wearable electronic device (e.g., wearable electronic device 300) may include a set of receiver sensors positioned on the inner surface of the wearable electronic device. The inner surface may be in contact with the user of the wearable electronic device when the user is wearing the wearable electronic device, and at least one of the receiver sensors in the set of receiver sensors may be positioned beneath a protrusion on the inner surface of the wearable electronic device. The protrusion may improve light transmission, light collection, or both. One or more protrusions 310 in Figure 3 are shown for illustrative purposes only, and it should be understood that one or more protrusions 310 may be above an LED, a photodetector, or any combination thereof. The wearable electronic device 300 may include a first set of transmitter sensors positioned adjacent to a first set of optical sensors on the inner surface. The first set of transmitter sensors may include one or more transmitter sensors of a first wavelength. In some cases, the wearable electronic device 300 may include a second set of transmitter sensors positioned adjacent to a second set of optical sensors on the inner surface. The second set of transmitter sensors may include at least one transmitter sensor of a second wavelength and at least one transmitter sensor of a third wavelength.

[0091] The first set of receiver sensors may include at least two photodiodes 306. The first set of transmitter sensors may include at least two green LEDs 302, and the second set of light sensors may include at least one infrared LED 304 and at least one red LED 304 may be included. At least two photodiodes 306 may include a first photodiode 306-a and a second photodiode 306-b spaced apart from the first photodiode. At least two green LEDs may include a first green LED 302-a and a second green LED 302-b spaced between the first photodiode 306-a and the second photodiode 306-b. The first green LED 302-a may be positioned to the right of the first photodiode 306-a, and the second green LED 302-b may be positioned to the left of the second photodiode 306-b.

[0092] At least one infrared LED 304-a may be positioned to the right of the first green LED 302-a, and at least one red LED 304-b may be positioned to the right of the second green LED It may be located to the left of 302-b. At least one infrared LED 304-a and at least one red LED 304-b may be arranged adjacent to each other. The wearable electronic device 300 may include an additional infrared LED 304-c positioned to the left of the first photodiode 306-a. The additional infrared LED 304-a may be positioned such that the light emitted from the additional infrared LED 304-a is directed toward the second photodiode 306-b. This additional infrared LED 304-c may be used to detect whether the ring is fitted (for example, by determining whether the IR signal is blocked and not received by the photodetector 2). A third set of light sensors may be positioned below a protrusion on the inner surface of the wearable electronic device, the protrusion may be directed toward the user of the wearable electronic device.

[0093] In some examples, a wearable electronic device (e.g., a ring 104) may be configured to detect how tightly it fits the wearer based on the amount of ambient light detected by a photodetector, or accelerometer data, or both. For example, the ring may be configured to detect ambient light with one or more of several photodetector sensors and to determine if the detected ambient light exceeds a threshold. The threshold may be configured such that ambient light detected above the threshold indicates that the ring is loosely fitted to the finger. Based on the determination that the detected ambient light exceeds the threshold, the ring may identify a ring fit metric.

[0094] In some cases, the ring may be able to detect whether it fits snugly based on accelerometer data. This accelerometer data can be used independently or in conjunction with other ring fit data, such as ambient light detection. In some cases, the accelerometer data may indicate that the ring bounces, slides, or rotates along the finger by identifying additional artifacts within the accelerometer data. For example, if a user is jogging and the ring fits snugly and moves in sync with the hand, the predictable movement of the moving hand may be reflected in the accelerometer data. However, if the ring does not fit snugly, the accelerometer data may show less consistent or noisier movement than when the ring was fitted snugly.

[0095] Figure 4 shows an example of a wearable electronic device 400 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 400 may implement system 100, system 200, or both, or be implemented by them. In particular, the wearable electronic device 400 shows an example of a ring 104 (e.g., wearable device 104) as described with reference to Figures 1 and 2. The wearable electronic device 400 may be an example of a wearable electronic device 300 as described with reference to Figure 3. The wearable electronic device 400 has one or more green LEDs 402 (e.g., LEDs) at different positions The green LED 402 may include 402-a, 402-b). The green LED 402 may be contained under the projection 410 (e.g., projections 410-a, 410-b, 410-c) and collated with the photodiode 404 (e.g., photodiodes 404-a, 404-b). In Figure 4, the green LED 402 is located under the projection 410 between the photodiode 404 and the IR / red LED 406, but the green LED 402 may be located under the projection 410 such that the photodiode 404 is located between the green LED 402 and the IR / red LED 406.

[0096] In Figures 3 to 7, the photodiode may sample from an adjacent green LED (e.g., the nearest green LED). For example, photodiode 1 may generate a PPG signal in response to light received from green LED 1. In another example, photodiode 2 may generate a PPG signal in response to light received from green LED 2. In some implementations, in the example in Figure 4, photodiode 404 may generate a PPG signal in response to reflected light from green LED 402 located beneath the same protrusion 410.

[0097] Figure 5 shows an example of a wearable electronic device 500 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 500 may implement system 100, system 200, or both, or be implemented by them. The wearable electronic device 500 may include an example of a ring 104 (e.g., wearable device 104) as described with reference to Figures 1 and 2. The wearable electronic device 500 may be an example of wearable electronic devices 300 and 400 as described with reference to Figures 3 and 4. The wearable electronic device 500 may include green LEDs 502 (e.g., green LEDs 502-a, 502-b) in different positions. In the example shown in Figure 5, the wearable electronic device 500 shows an exemplary ring in which the photodiode 504 and projection 508 are located, with the green LED 502 positioned outside of projections 508-a, 508-b, and 508-c (e.g., below the circular inner housing 510), so that the photodiode 504 and projection 508 are positioned between the green LED 502 and the IR / red LED 506.

[0098] Figure 6 shows an example of a wearable electronic device 600 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 600 may implement system 100, system 200, or both, or be implemented by both. The wearable electronic device 600 may represent an example of a ring 104 (e.g., wearable device 104), as described with reference to Figures 1 and 2. The wearable electronic device 600 may be an example of wearable electronic devices 300 to 500, as described with reference to Figures 3 to 5.

[0099] The wearable electronic device 600 may include green LEDs 602 (e.g., green LEDs 602-a, 602-b) in different positions. In the example in Figure 6, the wearable electronic device 600 shows an exemplary ring in which green LEDs 602-a, 602-b are included under projections 608-a, 608-c, and photodiodes 604-a, 604-b are located under a circular inner housing 610 between green LED 602 ​​and IR / red LEDs 606-a, 606-b. In an alternative ring not shown, green LEDs 602-a and 602-b may be located below the protrusions 608-a and 608-c, and the photodiodes 604-a and 604-b may be located outside the green LED 602 ​​under the circular inner housing 610 such that the green LED 602 ​​is between the photodiode 604 and the IR / red LED 606.

[0100] Figure 7 shows an example of a wearable electronic device 700 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 700 may implement system 100, system 200, or both, or be implemented by them. The wearable electronic device 700 may represent an example of a ring 104 (e.g., wearable device 104), as described with reference to Figures 1 and 2. The wearable electronic device 700 may be an example of wearable electronic devices 300 to 600, as described with reference to Figures 3 to 6. In the example of Figure 7, the wearable electronic device 700 may include green LEDs 702-a, 702-b in different positions. For example, the green LEDs 702-a, 702-b may be located below protrusions 706-a, 706-b in the wearable electronic device 700, and the photodiodes 704-a, 704-b may be located below the green LEDs It may be located beneath the circular inner housing 708 between 702.

[0101] Figure 8 shows an example of a wearable electronic device 800 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable electronic device 800 may implement system 100, system 200, or both, or be implemented by both. The wearable electronic device 800 may represent an example of a ring 104 (e.g., wearable device 104), as described with reference to Figures 1 and 2. The wearable electronic device 800 may be an example of wearable electronic devices 300 to 700, as described with reference to Figures 3 to 7.

[0102] The wearable electronic device 900 may include a transmitter and receiver from Figure 8. In the example of Figure 8, the wearable electronic device 900 (e.g., ring 104) may include a red LED 902 positioned together with (e.g., next to) the IR LED 904. For example, the red LED 902 and the IR LED 904 may be positioned under a central projection 906 between two photodiodes 908-a, 908-b (e.g., photodiode 1 and photodiode 2). In this example, the red LED 902 can transmit light through a similar path to the IR LED 904. The wearable electronic device 900 (e.g., ring 104) may include a red LED 902 may be used to perform oxygen saturation measurement (e.g., SpO2). Placing the red LED 902 and IR LED 904 under the same projection 906 allows the red LED 902 and IR LED 904 to transmit into the finger (e.g., ring 104) of the user wearing the wearable electronic device 900 in a similar manner (e.g., in similar physical locations on the finger) that can similarly influence the LED signals during transmission. As described herein, reflection can be minimized when transmitted to the interface between the central projection and the skin.

[0103] Figure 10 shows an example of a process flow 1000 supporting a configurable PPG system according to an aspect of this disclosure. The operation of the process flow 1000 may be implemented by a wearable device or its components as described herein. For example, the operation of the process flow 1000 may be performed by a wearable device as described with reference to Figures 1 to 9. In some examples, the wearable device may execute a set of instructions for controlling the functional elements of the wearable device to perform the described functions. Additionally or alternatively, the wearable device may perform aspects of the described functions using dedicated hardware.

[0104] In 1000, the wearable device may select a wavelength for the wearable device's transmitter-receiver pair. In some implementations, the wearable device may activate or control a transmitter-receiver pair having a first wavelength to measure the PPG signal. For example, the wearable device may first activate / control an IR transmitter and photodiode or green transmitter-photodiode pair. In 1005, the wearable device may measure the PPG using the current transmitter-receiver wavelength. For example, the wearable device may acquire the PPG signal over time using a selected transmitter-receiver pair of the first wavelength until a processing module determines that a different wavelength of the transmitter should be evaluated.

[0105] In 1010, the wearable device may evaluate other transmitter-receiver wavelengths. In some implementations, the wearable device may determine whether another wavelength of the transmitter should be evaluated. For example, the wearable device may determine whether another wavelength of the transmitter should be evaluated based on selection criteria such as wavelength selection criteria, transmitter selection criteria, and / or receiver selection criteria as described herein. Wavelength selection criteria may include, but are not limited to, day / night hours, amount of user movement, and temperature, as described herein.

[0106] The selection criteria evaluated by the wearable device to determine whether to evaluate other wavelengths may depend on the currently selected wavelength and / or the next possible selected wavelength. For example, a wearable device may be configured to evaluate other wavelengths when a transition to other wavelengths may be beneficial (e.g., based on the current state). In some examples, a wearable device may be configured to evaluate the green wavelength when motion / exercise is detected, assuming that the green transmitter-receiver pair may be more effective during operation, while the ring is currently using the IR wavelength. In some other examples, a wearable device may be configured to evaluate the green wavelength when the ring is currently using the IR wavelength, assuming that the green transmitter-receiver pair may be less distracting during the day. If the wearable device is currently using the green transmitter-receiver pair, the wearable device may be configured to evaluate the IR wavelength when exercise / exercise is finished and / or at night. In another example, a wearable device may be configured to evaluate an IR wavelength when the wearable device is currently using a green wavelength, assuming that the IR transmitter-receiver pair is more effective at colder temperatures (e.g., user / ambient temperature) when the temperature is relatively low. For any current wavelength, the wearable device may be configured to evaluate other wavelengths if the signal strength is lower than what is sufficient using the transmitter for the current wavelength.

[0107] In some implementations, the criteria for transitioning between PPG wavelengths (e.g., IR or green) may vary depending on the current wavelength and the specific wavelength transition being performed. For example, since a green LED may be preferred during user activity, the transition criterion may tend to favor the selection of a green LED by requiring less movement for the transition from IR to green (e.g., less movement for the transition from green to IR). If the wearable device decides that a new transmitter wavelength should not be evaluated, in 1010, the wearable device may generate a PPG signal using the first wavelength. Note that the wearable device may switch the transmitter and / or receiver within the same wavelength in 1005 to obtain a better signal (e.g., according to Figures 6 and 7). If the wearable device decides in 1010 that a new transmitter wavelength should be evaluated, the wearable device may evaluate another transmitter-receiver wavelength (e.g., a second wavelength) in 1015. For example, a wearable device 1015 can try different transmitter-receiver combinations for a second wavelength to determine whether a better signal can be obtained using the second wavelength for the first wavelength.

[0108] At 1020, the wearable device may decide whether to select another wavelength (e.g., a second wavelength rather than the first wavelength). The wearable device may make the decision based on any selection criteria described herein, such as time, user movement, temperature, and signal quality. If the wearable device does not select the second wavelength, process flow 1000 proceeds to 1005, where a PPG signal is generated using the first wavelength. If the wearable device selects the second wavelength at 1020, the process flow proceeds to 1025, where the wearable device selects a new transmitter-receiver pair wavelength. The process flow then proceeds to 1005, where the wearable device measures the PPG signal according to the new current transmitter-receiver pair wavelength. The wearable device may then continue measuring the PPG signal, evaluating other wavelengths, and changing the transmitter wavelength according to the operations performed in 1005-1025.

[0109] A wearable device may acquire data (e.g., PPG data, temperature data, and exercise data) and make decisions based on the locally acquired data on the wearable device, but in some implementations, the wearable device may transmit the data to another computing device (e.g., a user device) for processing. In these implementations, the computing device (e.g., a user device) may process the acquired data and send commands / data back to the wearable device. The wearable device may then perform actions based on the received data / commands. In some examples, the computing device may decide when to switch wavelengths, transmitters, and / or receivers, as described herein. The computing device may then send data / commands to the wearable device that cause the wearable device to switch wavelengths, transmitters, and / or receivers. Thus, the data acquisition, processing, decisions, and commands described herein may be implemented to different degrees by the wearable device and / or other computing devices.

[0110] Figure 11 shows a block diagram 1100 of a device 1105 supporting a configurable PPG system according to an aspect of the present disclosure. Device 1105 may include an input module 1110, an output module 1115, and a wearable device manager 1120. Device 1105 may also include a processor. Each of these components may communicate with one another (for example, via one or more buses).

[0111] For example, the wearable device manager 1120 may include a sensor activation component 1125, a signal measurement component 1130, a signal quality component 1135, a sensor combination selection component 1140, or any combination thereof. In some examples, the wearable device manager 1120, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using, or otherwise in cooperation with, an input module 1110, an output module 1115, or both. For example, the wearable device manager 1120 may receive information from the input module 1110 and transmit information to the output module 1115, or may be integrated in combination with the input module 1110, the output module 1115, or both, to receive information, transmit information, or perform various other operations as described herein.

[0112] The wearable device manager 1120 may support the measurement of optical signals by a wearable electronic device in accordance with the examples disclosed herein. A sensor activation component 1125 may be configured, or optionally support, for activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located under a projection on the inner surface of the wearable electronic device. A signal measurement component 1130 may be configured, or otherwise support, for measuring one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time. A signal quality component 1135 may be configured, or otherwise support, for determining a signal quality metric associated with one or more signals. The sensor combination selection component 1140 is configured as a means for selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric, or may otherwise support this.

[0113] Figure 12 shows a block diagram 1200 of a wearable device manager 1220 supporting a configurable PPG system according to an aspect of the present disclosure. The wearable device manager 1220 may be an example of an aspect of the wearable device manager or wearable device manager 1120, or both, as described herein. The wearable device manager 1220, or various components thereof, may be an example of means for performing various aspects of the configurable PPG system described herein. For example, the wearable device manager 1220 may include a sensor activation component 1225, a signal measurement component 1230, a signal quality component 1235, a sensor combination selection component 1240, a PPG signal component 1245, a wavelength selection component 1250, a sampling rate component 1255, a power output level component 1260, a sensor activation time component 1265, an ambient light component 1270, a ring fit identification component 1275, or any combination thereof. Each of these components may communicate with one another directly or indirectly (for example, via one or more buses).

[0114] The wearable device manager 1220 may support the measurement of optical signals by a wearable electronic device in accordance with the examples disclosed herein. A sensor activation component 1225 may be configured, or optionally support, for activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located under a projection on the inner surface of the wearable electronic device. A signal measurement component 1230 may be configured, or otherwise support, for measuring one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time. A signal quality component 1235 may be configured, or otherwise support, for determining a signal quality metric associated with one or more signals. The sensor combination selection component 1240 is configured as a means for selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric, or may otherwise support such selection.

[0115] In some examples, to support the selection of a second combination of optical sensors, the sensor combination selection component 1240 may be configured, or otherwise support, means for selecting a second set of transmitter sensors, a second set of receiver sensors, or a combination thereof, at least in part on a signal quality metric.

[0116] In some examples, a second set of transmitter sensors and a second set of receiver sensors are positioned around the wearable electronic device. In some examples, the selection of a second combination of light sensors is at least partially based on the positioning of the second set of transmitter sensors and the second set of receiver sensors.

[0117] In some examples, the wearable electronic device comprises a first photodiode and a second photodiode, the first and second photodiodes located beneath a first and second protrusion within the wearable electronic device, respectively.

[0118] In some examples, at least one transmitter sensor of a first wavelength comprises a first green LED and a second green LED, where the first green LED is positioned to the right of the first photodiode and the second green LED is positioned to the left of the second photodiode.

[0119] In some examples, at least one transmitter sensor of a second wavelength is equipped with an infrared LED, and the infrared LED is positioned to the right of the first green LED.

[0120] In some examples, at least one transmitter sensor of a third wavelength includes a red LED, which is positioned to the left of a second green LED, and the red LED and infrared LED are positioned adjacent to each other.

[0121] In some embodiments, the infrared LED and the red LED are positioned beneath a third protrusion within the wearable electronic device.

[0122] In some examples, to support the selection of a second combination of optical sensors, the sensor combination selection component 1240 is configured as a means for selecting a pair of optical sensors, or may otherwise support it, the pair of optical sensors comprising at least one transmitter optical sensor and at least one receiver optical sensor.

[0123] In some examples, to support the measurement of one or more signals, the PPG signal component 1245 may be configured by a set of receiver sensors as a means for measuring PPG signals from a set of transmitter sensors, or otherwise support it.

[0124] In some examples, to support determining a signal quality metric, the PPG signal component 1245 may be configured, or otherwise support, means for determining the amplitude of the PPG signal, the amount of noise in the PPG signal, the form of the PPG signal, the power consumption associated with determining the PPG signal, or a combination thereof.

[0125] In some examples, the wavelength selection component 1250 is configured, or may support, means for selecting a wavelength from a set of wavelengths based at least in part on a set of parameters for use in generating one or more signals, wherein the selection of a second combination of light sensors is based at least in part on the selected wavelength.

[0126] In some examples, to support the selection of a second combination of light sensors, the wavelength selection component 1250 may be configured as a means for selecting between at least one transmitter sensor of a first wavelength or at least one transmitter sensor of a second wavelength, or may support such selection.

[0127] In some examples, to support determining a signal quality metric, the signal quality component 1235 may be configured, or otherwise support, means for determining signal quality, time, user motion of a wearable electronic device, temperature, wavelengths associated with a first set of light sensors, or a combination thereof.

[0128] In some examples, the sampling rate component 1255 may be configured, or otherwise support, a means for updating the sampling rate associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric.

[0129] In some examples, the power output level component 1260 may be configured, or otherwise support, means for updating the power output levels associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric.

[0130] In some examples, the sensor activation time component 1265 may be configured, or otherwise support, means for updating the sensor activation time associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric.

[0131] In some examples, the ambient light component 1270 is configured, or may support, for detecting ambient light using one or more receiver sensors from a plurality of receiver sensors. In some examples, the ambient light component 1270 is configured, or may support, for determining whether the detected ambient light exceeds a threshold. In some examples, the Ring Fit identification component 1275 is configured, or may support, for identifying a Ring Fit metric, at least in part, based on determining whether the detected ambient light exceeds a threshold, the Ring Fit metric representing the gap between the inner surface of the wearable electronic device and the skin of the user wearing the wearable electronic device.

[0132] In some examples, the sensor combination selection component 1240 may be configured as a means for activating an infrared LED dedicated to finger placement detection, or may support such activation. In some examples, the Ring Fit identification component 1275 may be configured as a means for determining, or possibly support such activation, whether the wearable electronic device is being worn by a user, at least in part on whether an activated infrared LED dedicated to finger placement detection is detected by one or more of the receiver sensors.

[0133] Figure 13 shows a diagram of system 1300 including a device 1305 that supports a configurable PPG system according to an aspect of the present disclosure. Device 1305 may be an example of, or include, a component of, device 1105 as described herein. Device 1305 may include an example of a wearable device 104 as previously described herein. Device 1305 may include components for bidirectional communication, including components for transmitting and receiving communications with a user device 106 and a server 110, such as a wearable device manager 1320, a communications module 1310, an antenna 1315, a sensor component 1325, a power module 1330, a memory 1335, a processor 1340, and a wireless device 1350. These components communicate electronically via one or more buses (e.g., bus 1345) or may be coupled (e.g., operably, communicatively, functionally, electronically, electrically).

[0134] The wearable device manager 1320 may support the measurement of optical signals by a wearable electronic device, in accordance with the examples disclosed herein. For example, the wearable device manager 1320 may be configured, or optionally support, means for activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located under a projection on the inner surface of the wearable electronic device. The wearable device manager 1320 may be configured, or optionally support, means for measuring one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time. The wearable device manager 1320 may be configured, or otherwise support, means for determining a signal quality metric associated with one or more signals. The wearable device manager 1320 may be configured, or possibly support, means for selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric.

[0135] Figure 14 shows a flowchart illustrating a method 1400 supporting a configurable PPG system according to an aspect of this disclosure. The operation of method 1400 may be performed by a wearable device or its components as described herein. For example, the operation of method 1400 may be performed by a wearable device as described with reference to Figures 1 to 13. In some examples, the wearable device may execute a set of instructions for controlling the functional elements of the wearable device to perform the described functions. Additionally or alternatively, the wearable device may use dedicated hardware to perform aspects of the functions described.

[0136] In 1405, the method may include activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located below a protrusion on the inner surface of the wearable electronic device. The operation of 1405 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1405 may be performed by a sensor activation component 1225, as described with reference to Figure 12.

[0137] In 1410, the method may include measuring one or more signals from a set of transmitter sensors in a set of receiver sensors at a first time. Operation of 1410 may be performed according to the examples disclosed herein. In some examples, the operation of 1410 may be performed by a signal measurement component 1230, as described with reference to Figure 12.

[0138] In 1415, the method may include determining a signal quality metric associated with one or more signals. The operation of 1415 may be performed according to the examples disclosed herein. In some examples, the operation of 1415 may be performed by the signal quality component 1235, as described with reference to Figure 12.

[0139] In 1420, the method may include selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric. Operation of 1420 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1420 may be performed by a sensor combination selection component 1240, as described with reference to Figure 12.

[0140] Figure 15 shows a flowchart illustrating method 1500 supporting a configurable PPG system according to an aspect of this disclosure. The operation of method 1500 may be performed by a wearable device or its components as described herein. For example, the operation of method 1500 may be performed by a wearable device as described with reference to Figures 1 to 13. In some examples, the wearable device may execute a set of instructions for controlling the functional elements of the wearable device to perform the described functions. Additionally or alternatively, the wearable device may perform aspects of the described functions using dedicated hardware.

[0141] In 1505, the method may include activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located below a projection on the inner surface of the wearable electronic device. The operation of 1505 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1505 may be performed by a sensor activation component 1225, as described with reference to Figure 12.

[0142] In 1510, the method may include measuring one or more signals from a set of transmitter sensors in a set of receiver sensors at a first time. Operation of 1510 may be performed according to the examples disclosed herein. In some examples, the operation of 1510 may be performed by a signal measurement component 1230, as described with reference to Figure 12.

[0143] In 1515, the method may include determining a signal quality metric associated with one or more signals. The operation of 1515 may be performed according to the examples disclosed herein. In some examples, the operation of 1515 may be performed by the signal quality component 1235, as described with reference to Figure 12.

[0144] In 1520, the method may include updating the sampling rate associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric. Operation of 1520 may be performed according to the examples disclosed herein. In some examples, the operation of 1520 may be performed by the sampling rate component 1255, as described with reference to Figure 12.

[0145] In 1525, the method may include selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric. The operation of 1525 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1525 may be performed by a sensor combination selection component 1240, as described with reference to Figure 12.

[0146] Figure 16 shows a flowchart illustrating a method 1600 supporting a configurable PPG system according to an aspect of this disclosure. The operation of method 1600 may be performed by a wearable device or its components as described herein. For example, the operation of method 1600 may be performed by a wearable device as described with reference to Figures 1 to 13. In some examples, the wearable device may execute a set of instructions for controlling the functional elements of the wearable device to perform the described functions. Additionally or alternatively, the wearable device may perform aspects of the described functions using dedicated hardware.

[0147] In 1605, the method may include activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is located below a protrusion on the inner surface of the wearable electronic device. The operation of 1605 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1605 may be performed by a sensor activation component 1225, as described with reference to Figure 12.

[0148] In 1610, the method may include measuring one or more signals from a set of transmitter sensors in a set of receiver sensors at a first time. Operation of 1610 may be performed according to the examples disclosed herein. In some examples, the operation of 1610 may be performed by a signal measurement component 1230, as described with reference to Figure 12.

[0149] In 1615, the method may include detecting ambient light using one or more photodetectors from a plurality of photodetectors. The operation of 1615 may be performed according to the examples disclosed herein. In some examples, the operation of 1615 may be performed by the ambient light component 1270, as described with reference to Figure 12.

[0150] In 1620, the method may include determining that the detected ambient light exceeds a threshold. The operation of 1620 may be performed according to the examples disclosed herein. In some examples, the operation of 1620 may be performed by the ambient light component 1270, as described with reference to Figure 12.

[0151] In 1625, the method may include identifying a Ring Fit metric, at least in part, based on determining that the detected ambient light exceeds a threshold, the Ring Fit metric indicating a gap between the inner surface of the wearable electronic device and the skin of the user wearing the wearable electronic device. The operation of 1625 may be performed according to the examples disclosed herein. In some examples, the operation of 1625 may be performed by a Ring Fit identification component 1275, as described with reference to Figure 12.

[0152] In 1630, the method may include determining a signal quality metric associated with one or more signals. The operation of 1630 may be performed according to the examples disclosed herein. In some examples, the operation of 1630 may be performed by the signal quality component 1235, as described with reference to Figure 12.

[0153] In 1635, the method may include selecting a second combination of optical sensors for use at a second time, at least in part, based on a signal quality metric. The operation of 1635 may be performed according to the examples disclosed herein. In some examples, the mode of operation of 1635 may be performed by a sensor combination selection component 1240, as described with reference to Figure 12.

[0154] The methods described above illustrate possible implementations; the operations and steps may be rearranged or, in some cases, modified, and other implementations are possible. Furthermore, two or more aspects of the methods may be combined.

[0155] A method for measuring optical signals by a wearable electronic device is described. The method is to activate a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors is positioned below a projection on the inner surface of the wearable electronic device, and the method may include activating, measuring one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time, determining a signal quality metric associated with one or more signals, and selecting a second combination of optical sensors for use at a second time, at least in part based on the signal quality metric.

[0156] An apparatus for measuring optical signals by a wearable electronic device is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to activate a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, at least one optical sensor of the first combination of optical sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and may be configured to measure one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time, determine a signal quality metric associated with one or more signals, and select a second combination of optical sensors for use at a second time, at least based on the signal quality metric.

[0157] An apparatus for measuring optical signals by a wearable electronic device is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to activate a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, at least one optical sensor of the first combination of optical sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and may be configured to measure one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time, determine a signal quality metric associated with one or more signals, and select a second combination of optical sensors for use at a second time, at least based on the signal quality metric.

[0158] Another apparatus for measuring optical signals by a wearable electronic device is described. The apparatus may include means for activating a first combination of optical sensors, the first combination of optical sensors comprising a set of transmitter sensors from a plurality of transmitter sensors of a wearable electronic device and a set of receiver sensors from a plurality of receiver sensors, the plurality of transmitter sensors comprising at least one transmitter sensor of a first wavelength, at least one transmitter sensor of a second wavelength, and at least one transmitter sensor of a third wavelength, and at least one optical sensor of the first combination of optical sensors being positioned under a projection on the inner surface of the wearable electronic device; means for measuring one or more signals from the set of transmitter sensors in the set of receiver sensors at a first time; means for determining a signal quality metric associated with one or more signals; and means for selecting a second combination of optical sensors for use at a second time, at least in part on the signal quality metric.

[0159] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, a second set of transmitter sensors and a second set of receiver sensors may be arranged around a wearable electronic device, and the selection of a second combination of optical sensors may be at least in part based on the arrangement of the second set of transmitter sensors and the second set of receiver sensors.

[0160] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, the wearable electronic device comprises a first photodiode and a second photodiode, the first and second photodiodes respectively located beneath a first projection and a second projection within the wearable electronic device.

[0161] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, at least one transmitter sensor of a first wavelength comprises a first green LED and a second green LED, the first green LED being positioned to the right of a first photodiode and the second green LED being positioned to the left of a second photodiode.

[0162] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, at least one transmitter sensor of a second wavelength comprises an infrared LED, the infrared LED being positioned to the right of a first green LED.

[0163] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, at least one transmitter sensor of a third wavelength comprises a red LED, the red LED being positioned to the left of a second green LED, and the red LED and infrared LED being positioned adjacent to each other.

[0164] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, infrared LEDs and red LEDs may be positioned beneath a third protrusion in a wearable electronic device.

[0165] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, selecting a second combination of optical sensors may include an operation, feature, means, or instruction for selecting a pair of optical sensors, the pair of optical sensors comprising at least one transmitter optical sensor and at least one receiver optical sensor.

[0166] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, measuring one or more signals may include an operation, feature, means, or instruction for measuring PPG signals from a set of transmitter sensors using a set of receiver sensors.

[0167] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, determining a signal quality metric may include operations, features, means, or instructions for determining the amplitude of a PPG signal, the amount of noise in the PPG signal, the form of the PPG signal, the power consumption associated with determining the PPG signal, or a combination thereof.

[0168] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, selecting a second combination of optical sensors may include an operation, feature, means, or instruction for selecting between at least one transmitter sensor of a first wavelength or at least one transmitter sensor of a second wavelength.

[0169] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, determining a signal quality metric may include actions, features, means, or instructions for determining signal quality, time, user motion of a wearable electronic device, temperature, wavelengths associated with a first set of optical sensors, or combinations thereof.

[0170] Some examples of methods, apparatus, and non-temporary computer-readable media described herein may further include operations, features, means, or instructions for updating the sampling rate associated with a first combination of optical sensors, a second combination of optical sensors, or both, at least in part on a signal quality metric.

[0171] Some examples of methods, apparatus, and non-temporary computer-readable media described herein may further include operations, features, means, or instructions for updating power output levels associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric.

[0172] Some examples of methods, apparatus, and non-temporary computer-readable media described herein may further include operations, features, means, or instructions for updating sensor activation times associated with a first combination of optical sensors, a second combination of optical sensors, or both, based at least in part on a signal quality metric.

[0173] Some examples of methods, apparatus, and non-temporary computer-readable media described herein may further include operations, features, means, or instructions for detecting ambient light using one or more receiver sensors from a plurality of receiver sensors, determining that the detected ambient light exceeds a threshold, and identifying a Ring Fit metric at least in part on determining that the detected ambient light exceeds a threshold, wherein the Ring Fit metric represents the gap between the inner surface of a wearable electronic device and the skin of the user wearing the wearable electronic device.

[0174] In some examples of the methods, apparatus, and non-temporary computer-readable media described herein, the methods, apparatus, and non-temporary computer-readable media may include further operations, features, means, or instructions for activating an infrared LED which may be dedicated to finger placement detection, and determining whether a wearable electronic device may be worn by a user, at least in part on whether the activated infrared LED which may be dedicated to finger placement detection can be detected by one or more of a plurality of receiver sensors.

[0175] A wearable electronic device for measuring optical signals is described. The wearable electronic device may include a pair of receiving sensors arranged on the inner surface of the wearable electronic device, the inner surface being in contact with the user of the wearable electronic device when the user is wearing the wearable electronic device, and at least one of the pair of receiving sensors being positioned below a protrusion on the inner surface of the wearable electronic device. The wearable electronic device may include a first transmitter sensor set arranged adjacent to a first set of optical sensors on the inner surface, comprising one or more transmitter sensors of a first wavelength, and a second transmitter sensor set arranged adjacent to a second set of optical sensors on the inner surface, comprising at least one transmitter sensor of a second wavelength and at least one transmitter sensor of a third wavelength.

[0176] In some examples of wearable electronic devices, a first set of receiver sensors may further include at least two photodiodes, a first set of transmitter sensors may include at least two green LEDs, and a second set of light sensors may include at least one infrared LED and at least one red LED.

[0177] In some examples of wearable electronic devices, the at least two photodiodes may further include a first photodiode and a second photodiode, with a space between them.

[0178] In some examples of wearable electronic devices, the at least two green LEDs may further include a first green LED and a second green LED positioned in the space between a first photodiode and a second photodiode, with the first green LED positioned to the right of the first photodiode and the second green LED positioned to the left of the second photodiode.

[0179] Some examples of wearable electronic devices may further include an additional infrared LED positioned to the left of the first photodiode, the additional infrared LED being positioned such that the light emitted from the additional infrared LED can be directed toward the second photodiode.

[0180] In some examples of wearable electronic devices, a third set of light sensors may be positioned beneath a protrusion on the inner surface of the wearable electronic device, which is directed toward the user of the wearable electronic device.

[0181] The descriptions provided herein with respect to the accompanying drawings describe exemplary configurations and do not necessarily represent all examples that may be implemented or that fall within the scope of the claims. The term “exemplary” as used herein means “acting as an example, case, or illustration,” and does not mean “preferred” or “advantageous over other examples.” Detailed descriptions include specific details to give an understanding of the techniques described. However, these techniques may be implemented without these specific details. In some cases, well-known structures and devices are shown in the form of block diagrams to avoid obscuring the concepts of the described examples.

[0182] In the attached diagram, similar components or features may have the same reference label. Furthermore, various components of the same type may be distinguished by following the reference label with a dash and a second label that distinguishes similar components. Where only the first reference label is used herein, the description is applicable to any one of the similar components having the same first reference label, regardless of the second reference label.

[0183] The information and signals described herein may be represented using any of the various different techniques and methods. For example, the data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltage, electric current, electromagnetic waves, magnetic fields or magnetic particles, light fields or optical particles, or any combination thereof.

[0184] The various exemplary blocks and modules described in relation to the disclosure herein may be implemented or run using general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, individual gate or transistor logic, individual hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but alternatively, a processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors working with a DSP core, or any other such configuration).

[0185] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. When implemented in software executed by a processor, the functions may be stored or transmitted as one or more instructions or codes on a computer-readable medium. Other examples and implementations are within the scope of this disclosure and the accompanying claims. For example, depending on the nature of the software, the functions described above may be implemented using software executed by a processor, hardware, firmware, hardwiring, or any combination thereof. Features implementing the functions may also be physically located in various locations, including being distributed so that parts of the functions are implemented in different physical locations. Also, as used herein, including in the claims, "or" used in a list of items (e.g., a list of items preceded by a phrase such as "at least one" or "one or more") means an inclusive list such as, for example, a list of at least one of A, B, or C meaning A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Also, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as “based on Condition A” may be based on both Condition A and Condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same way as the phrase “based at least in part on.”

[0186] Computer-readable media include both non-temporary computer storage media and communication media, including any media that facilitates the transfer of computer programs from one location to another. Non-temporary storage media can be any available media that can be accessed by a general-purpose or dedicated computer. Examples, but not limitations, of non-temporary computer-readable media may include RAM, ROM, electrically erasable programmable ROM (EEPROM), compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-temporary media that can be used to carry or store desired program code means in the form of instructions or data structures, and can be accessed by a general-purpose or dedicated computer or general-purpose or dedicated processor. Any connection is also appropriately referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. As used herein, the terms "disk" and "disc" include CDs, laserdiscs, optical discs, digital multipurpose discs (DVDs), floppy disks (registered trademark), and Blu-ray discs, where a disk typically reproduces data magnetically, and a disc reproduces data optically using a laser. Any combination of the above is also included within the scope of computer-readable media.

[0187] The descriptions herein are provided to enable those skilled in the art to create or use this disclosure. Various modifications to this disclosure will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of this disclosure. Accordingly, this disclosure is not limited to the examples and designs described herein and should be given the broadest scope that corresponds to the principles and novel features disclosed herein.

Claims

1. It is a wearable electronic device, A set of receiver sensors disposed on or inside the inner surface of the wearable electronic device, wherein the inner surface comes into contact with the user when the wearable electronic device is wearing the wearable electronic device, and at least one of the receiver sensors in the set of receiver sensors is disposed below a protrusion on the inner surface of the wearable electronic device, A first set of transmitter sensors arranged adjacent to the set of receiver sensors on or inside the inner surface, wherein the first set of transmitter sensors comprises one or more transmitter sensors of a first wavelength, A wearable electronic device comprising a second set of transmitter sensors arranged adjacent to the set of receiver sensors on or inside the inner surface, wherein the second set of transmitter sensors comprises at least one transmitter sensor of a second wavelength and at least one transmitter sensor of a third wavelength.

2. The wearable electronic device according to claim 1, wherein the set of receiver sensors comprises at least two photodiodes, the first set of transmitter sensors comprises at least two green LEDs, and the second set of transmitter sensors comprises at least one infrared LED and at least one red LED.

3. The wearable electronic device according to claim 1, further comprising a housing having the inner and outer surfaces, wherein the housing is ring-shaped and the inner and outer surfaces are curved.

4. The device further includes one or more processors communicably coupled to the set of receiver sensors, the first set of transmitter sensors, and the second set of transmitter sensors, the one or more processors providing the wearable electronic device with Activating a first combination of light sensors, wherein the first combination of light sensors comprises at least one receiver sensor from the set of receiver sensors and at least one transmitter sensor from at least one of the first set and the second set of transmitter sensors. In the first time period, one or more signals from the at least one transmitter sensor are measured via the at least one receiver sensor of the first combination of light sensors, Determining the signal quality metric associated with the one or more signals, The wearable electronic device according to claim 1, configured to select a combination of optical sensors for use at a second time, based at least in part on the signal quality metric, wherein the selected combination of optical sensors comprises the first combination of optical sensors or a second combination different from the first combination of optical sensors.

5. The wearable electronic device according to claim 4, wherein the set of receiver sensors is arranged at least a first radial position on or within the inner surface, the first set of transmitter sensors is arranged at least a second radial position on or within the inner surface, and the second set of transmitter sensors is arranged at least a third radial position on or within the inner surface.

6. The wearable electronic device according to claim 5, wherein the projection extends across the first radial position and the second radial position such that the at least one receiver sensor of the set of receiver sensors and the at least one transmitter sensor of the first set of transmitter sensors are positioned below the projection.

7. At the first radial position, a first projection extending from the inner surface of the wearable electronic device, The wearable electronic device according to claim 5, further comprising a second projection extending from the inner surface of the wearable electronic device at the second radial position or the third radial position.

8. At the second radial position, the first projection extends from the inner surface of the wearable electronic device, The wearable electronic device according to claim 5, further comprising a second projection extending from the inner surface of the wearable electronic device at the third radial position.

9. The first set of transmitter sensors comprises a first transmitter sensor at a second radial position and a second transmitter sensor at a fourth radial position, wherein the first and second transmitter sensors are configured to emit light associated with the first wavelength, and the one or more processors provide the wearable electronic device with Activating the first combination of optical sensors comprising the first transmitter sensor and at least one receiver sensor from the set of receiver sensors, The wearable electronic device according to claim 5, further configured to allow the selection of a second combination of optical sensors for use at a second time, based at least in part on the signal quality metric, wherein the second combination of optical sensors comprises the second transmitter sensor and at least one receiver sensor from the set of receiver sensors, an additional receiver sensor from the set of receiver sensors, or both.

10. The one or more processors mentioned above are provided to the wearable electronic device. Activating the first combination of light sensors comprising at least one transmitter sensor configured to emit light associated with the first wavelength, at least one transmitter sensor configured to emit light associated with the second wavelength, and at least one transmitter sensor configured to emit light associated with the third wavelength, The wearable electronic device according to claim 4, further configured to allow the selection of the second combination of optical sensors for use at the second time, based at least in part on the signal quality metric.

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