Photovoltaic module and method of operating the same

Abstract

A photoelectric module is disclosed that is operable to measure proximity independent of the reflectivity of the surface of the object, and in some implementations is operable to measure a property of a stationary or moving object, such as surface reflectivity or absorptivity. For example, in some instances, the photoelectric module is operable to determine, for example, pulse rate / peripheral blood circulation and / or blood oxygen level of a moving object, such as an appendage of a user. For example, the photoelectric module can be used to measure peripheral blood circulation while a user of the photoelectric module is engaged in physical activity, such as walking, running, or cycling.

Description

Background Art

[0001] The distance between an object and a reference point can be determined by a variety of techniques. For example, proximity measurement techniques using small and low-cost optoelectronic modules have become nearly ubiquitous in consumer electronic devices and related technologies (e.g., those integrated into smartphones and tablets). These optoelectronic modules typically use a light-emitting component such as a light-emitting diode to direct light onto an object, and a light-sensitive component such as a photodiode to collect light reflected from the object. In some instances, the intensity of the collected light is related to (e.g., proportional to) the distance between the object and the optoelectronic proximity sensor.

[0002] The same hardware used to determine proximity can also be used for other applications, such as determining a user's pulse rate, peripheral blood circulation, or blood oxygen level. For example, a user of a module including a light emitting diode and a photodiode can place the module near an appendage with peripheral blood circulation (e.g., a finger, palm, or ear). The light emitted by the light emitting diode can exhibit an absorption that is related to the blood volume, so that if multiple intensity values ​​are collected over a period of time, then at any instance, the intensity of the light reflected to the photodiode corresponds to the user's blood volume at any time.

[0003] These and other applications present some significant challenges. For example, objects exhibit a range of surface reflectances. For example, in instances where the object is a finger, palm, or ear, the surface reflectance of the object may be heavily dependent on skin pigmentation. Therefore, there is a need for an optoelectronic module that is operable to collect data, such as proximity data, independent of the object's surface reflectance.

[0004] Further, while optoelectronic modules can be used for applications such as measuring peripheral blood circulation of stationary users, their efficiency is sometimes lower for users engaged in activities that require even moderate levels of movement (e.g., walking, running, hiking, etc.). In this case, the optoelectronic modules can exhibit module displacement (i.e., independent of the movement of the object / user). For example, when collecting intensity values ​​in one instance, the module may be at a first distance from the user's appendage. Then, when collecting intensity values ​​in another instance (i.e., after module displacement), the module may be at another different distance from the user's appendage. The collected intensity values ​​depend on different distances and different blood volumes, and may become useless without additional information or means to correct for different distances. Therefore, there is a need for optoelectronic modules that are operable to collect data such as absorption data independently of module displacement. Summary of the invention

[0005] The present disclosure describes an optoelectronic module operable to measure proximity. In some implementations, the optoelectronic module is operable to measure proximity independently of the reflectivity of the object surface. In some implementations, the optoelectronic module is operable to measure proximity and intensity-related properties of an object (e.g., a user's peripheral blood circulation) independently of module displacement. The present disclosure also describes a method of operating such an optoelectronic module.

[0006] According to a first aspect, for example, an optoelectronic module includes an illumination module and a detection module arranged adjacent to the illumination module. The illumination module includes a light emitting component and an illumination optical assembly. The light emitting component is operable to generate emission light incident on the illumination optical assembly, wherein the emission light is characterized by a dominant wavelength.

[0007] The detection module also includes a detection optical assembly and an array of photosensitive components arranged in a plane. The array includes a plurality of photosensitive components. Each photosensitive component is characterized by a coordinate position, and each photosensitive component is sensitive to a dominant wavelength. The detection optical assembly is characterized by a focal length and an optical axis. The detection optical assembly is aligned with the array of photosensitive components so that the focal length is incident on the plane and the optical axis is substantially perpendicular to the plane.

[0008] Further, the emitted light incident on the illumination optical assembly produces illumination together with the illumination optical assembly. The illumination module is operable to direct the illumination to an object arranged at a distance from the optoelectronic module. The detection module is operable to collect reflections of the illumination reflected from the object, and is further operable to convert the collected reflections into a signal by at least one of the photosensitive components within the array of photosensitive components. The signal is associated with a specific coordinate position of at least one photosensitive component from which the signal is converted. In addition, the signal is characterized by a signal amplitude. The specific coordinate position is associated with the distance at which the object is arranged from the optoelectronic module.

[0009] In some implementations, the optoelectronic module includes an intensity modulator operable to modulate the intensity of emitted light generated by the light emitting component.

[0010] In some implementations, the optoelectronic module includes an intensity modulator operable to modulate electrical power to the light emitting component such that an intensity of emitted light generated by the light emitting component is modulated.

[0011] In some implementations, the optoelectronic module includes a signal characterized by a signal amplitude, and the optoelectronic module further includes circuitry operable to modulate, via the intensity modulator, an intensity of emitted light generated by the light emitting component as a function of the signal amplitude.

[0012] In some implementations, the optoelectronic module includes a light emitting module, which further includes an auxiliary light emitting component. The auxiliary light emitting component is operable to generate auxiliary emission light incident on the illumination optical component. The auxiliary emission light is characterized by an auxiliary wavelength. The auxiliary emission light incident on the illumination optical component produces auxiliary illumination together with the illumination optical component. The illumination module is operable to direct the auxiliary illumination to an object arranged at a distance from the optoelectronic module.

[0013] In some implementations, the optoelectronic module includes an auxiliary array of photosensitive components arranged in a plane. The auxiliary array includes a plurality of auxiliary photosensitive components. Each auxiliary photosensitive component is characterized by a coordinate position, and each auxiliary photosensitive component is sensitive to an auxiliary wavelength.

[0014] In some implementations, the optoelectronic module includes a detection module operable to collect reflections of auxiliary illumination emitted from the object. The detection module is further operable to convert the collected reflections into an auxiliary signal by at least one auxiliary photosensitive component within an auxiliary array of photosensitive components. The auxiliary signal is associated with a specific coordinate position of the at least one auxiliary photosensitive component from which the auxiliary signal is converted. In addition, the auxiliary signal is characterized by an auxiliary signal amplitude. The specific coordinate position is associated with a distance at which the object is arranged from the optoelectronic module.

[0015] In some implementations, the optoelectronic module includes an intensity modulator operable to modulate the intensity of the auxiliary emission light generated by the auxiliary light emitting component.

[0016] In some implementations, the optoelectronic module includes an intensity modulator operable to modulate electrical power to the auxiliary lighting component such that an intensity of the auxiliary emitted light generated by the auxiliary lighting component is modulated.

[0017] In some implementations, the optoelectronic module includes an auxiliary signal characterized by an auxiliary signal amplitude. The optoelectronic module further includes a circuit operable to modulate the intensity of the auxiliary emission light generated by the auxiliary lighting component according to the auxiliary signal amplitude via an intensity modulator.

[0018] In some implementations, when the auxiliary signal amplitude is less than a threshold intensity value, the intensity of the auxiliary emission light generated by the auxiliary lighting component included in the optoelectronic module is increased.

[0019] In some implementations, when the auxiliary signal amplitude is greater than a threshold intensity value, the intensity of the auxiliary emission light generated by an auxiliary lighting component included in the optoelectronic module is reduced.

[0020] In some implementations, the optoelectronic module includes one or more processors communicatively coupled to the illumination module, the detection module, and the intensity modulator. The optoelectronic module further includes a non-transitory computer readable medium including instructions stored thereon, which when executed on the processor, perform the following operations, including:

[0021] When the signal amplitude is less than a threshold intensity value, increasing the intensity of the emitted light generated by the light emitting component; and

[0022] When the signal amplitude is greater than the threshold intensity value, the intensity of the emitted light generated by the light emitting component is reduced.

[0023] In some implementations, the optoelectronic module includes one or more processors communicatively coupled to the illumination module, the detection module, and the intensity modulator. The optoelectronic module further includes a non-transitory computer readable medium including instructions stored thereon, which, when executed on the processor, perform the following operations, including:

[0024] When the signal amplitude is less than a threshold intensity value, increasing the intensity of the emitted light generated by the light emitting component; and

[0025] reducing the intensity of the emitted light generated by the light emitting component when the signal amplitude is greater than a threshold intensity value;

[0026] When the auxiliary signal amplitude is less than a threshold intensity value, increasing the intensity of the auxiliary emission light generated by the auxiliary light emitting component; and

[0027] When the auxiliary signal amplitude is greater than the threshold intensity value, the intensity of the auxiliary emission light generated by the auxiliary lighting component is reduced.

[0028] In some implementations, an optoelectronic module includes a non-transitory computer-readable medium including instructions stored thereon that, when executed on a processor, normalize a signal amplitude by distance.

[0029] In some implementations, an optoelectronic module includes a non-transitory computer-readable medium including instructions stored thereon, which, when executed on a processor, perform the following operations, including:

[0030] directing illumination onto an object disposed at a distance from the photovoltaic module;

[0031] collecting reflections of illumination reflected from an object disposed at a distance from the photovoltaic module;

[0032] converting the collected reflections into a signal, which is associated with a specific coordinate location;

[0033] directing illumination onto an object at a subsequent distance from the photovoltaic module;

[0034] collecting reflections of illumination reflected from an object disposed at a subsequent distance from the photovoltaic module;

[0035] converting the collected reflections into a subsequent signal associated with a subsequent coordinate position, the subsequent signal being characterized by a subsequent signal amplitude;

[0036] Associating a specific coordinate location with a distance from the photovoltaic module;

[0037] associating subsequent coordinate positions with subsequent distances from the optoelectronic module;

[0038] normalizing the signal amplitude by the distance and normalizing subsequent signal amplitudes by subsequent distances; and

[0039] Compare the normalized signal amplitude to the normalized subsequent signal amplitude.

[0040] In some implementations, the optoelectronic module includes a non-transitory computer readable medium including instructions stored thereon that, when executed on a processor, compare the normalized signal amplitude and the normalized subsequent signal amplitude. The feature may include determining a difference between the signal amplitudes.

[0041] In some implementations, the optoelectronic module includes a non-transitory computer-readable medium including instructions stored thereon that, when executed on a processor, correlate the signal amplitude and a difference in a subsequent signal amplitude to peripheral blood circulation.

[0042] In some implementations, an optoelectronic module includes a non-transitory computer-readable medium including instructions stored thereon that, when executed on a processor, normalize a signal amplitude by distance and / or normalize an auxiliary signal by distance.

[0043] In some implementations, an optoelectronic module includes a non-transitory computer-readable medium including instructions stored thereon, which, when executed on a processor, perform the following operations, including:

[0044] directing illumination onto an object disposed at a distance from the photovoltaic module and directing auxiliary illumination onto an object disposed at a distance from the photovoltaic module;

[0045] collecting reflections of illumination reflected from an object disposed at a distance from the optoelectronic module and converting the collected reflections into a signal, the signal being associated with a coordinate position;

[0046] collecting reflections of auxiliary illumination reflected from an object disposed at a distance from the optoelectronic module and converting the collected reflections into auxiliary signals, the auxiliary signals being associated with coordinate positions;

[0047] directing illumination onto an object at a subsequent distance from the photovoltaic module and directing auxiliary illumination onto an object at a subsequent distance from the photovoltaic module;

[0048] collecting reflections of illumination reflected from an object disposed at a subsequent distance from the photovoltaic module;

[0049] converting the collected reflections into a subsequent signal associated with a subsequent coordinate position, the subsequent signal being characterized by a subsequent signal amplitude;

[0050] collecting reflections of auxiliary lighting reflected from an object disposed at a subsequent distance from the photovoltaic module;

[0051] converting the collected reflections into a subsequent auxiliary signal associated with a subsequent coordinate position, the subsequent auxiliary signal being characterized by a subsequent auxiliary signal amplitude;

[0052] Associating the coordinate position with the distance from the photovoltaic module;

[0053] associating subsequent coordinate positions with subsequent distances from the optoelectronic module;

[0054] normalizing signal amplitude by distance, and normalizing subsequent signal amplitudes by subsequent distances;

[0055] normalizing the auxiliary signal amplitude by the distance and normalizing subsequent auxiliary signal amplitudes by subsequent distances; and

[0056] Compare the normalized signal amplitude, the normalized subsequent signal amplitude, and the normalized auxiliary signal amplitude,

[0057] and the normalized subsequent auxiliary signal amplitude.

[0058] In some implementations, the optoelectronic module is operable to compare the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude. In some instances, comparing the signal amplitudes includes determining a difference between the signal amplitudes.

[0059] In some implementations, the optoelectronic module includes correlating the difference in signal amplitude to blood oxygen level.

[0060] According to another aspect, the present disclosure describes a method of operating a photovoltaic module, comprising:

[0061] When the signal amplitude is less than a threshold intensity value, increasing the intensity of the emitted light generated by the light emitting component; and

[0062] When the signal amplitude is greater than the threshold intensity value, the intensity of the emitted light generated by the light emitting component is reduced.

[0063] In some implementations, the method includes:

[0064] directing illumination onto an object disposed at a distance from the photovoltaic module;

[0065] collecting reflections of illumination reflected from an object disposed at a distance from the photovoltaic module;

[0066] converting the collected reflections into a signal, which is associated with a specific coordinate location;

[0067] directing illumination onto an object at a subsequent distance from the photovoltaic module;

[0068] collecting reflections of illumination reflected from an object disposed at a subsequent distance from the photovoltaic module;

[0069] converting the collected reflections into a subsequent signal associated with a subsequent coordinate position, the subsequent signal being characterized by a subsequent signal amplitude;

[0070] Associating a specific coordinate location with a distance from the photovoltaic module;

[0071] associating subsequent coordinate positions with subsequent distances from the optoelectronic module;

[0072] normalizing the signal amplitude by the distance and normalizing subsequent signal amplitudes by subsequent distances; and

[0073] Compare the normalized signal amplitude to the normalized subsequent signal amplitude.

[0074] In some implementations, the method includes comparing the normalized signal amplitude and the normalized subsequent signal amplitude. Comparing the normalized signal amplitude and the normalized subsequent signal amplitude can include determining a difference between the signal amplitudes.

[0075] In some implementations, the method includes correlating peripheral blood circulation with a difference between the signal amplitude and a subsequent signal amplitude.

[0076] Other aspects, features, and advantages will become apparent from the following detailed description, drawings, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1A and Figure 1B An example of an optoelectronic module operable to measure proximity data of an object independent of the object's surface reflectivity is depicted.

[0078] Figure 2A and Figure 2B An example of a method of operating a photovoltaic module is depicted.

[0079] Figure 3A and Figure 3B Examples of optoelectronic modules operable to measure proximity and intensity-related properties independent of module displacement are depicted.

[0080] Figure 4 Another example of a method of operating a photovoltaic module is depicted.

[0081] Figure 5A and Figure 5B Another example of an optoelectronic module operable to measure proximity and intensity-related properties independent of module displacement is depicted.

[0082] Figure 6 An example of a method of operating a photovoltaic module is depicted. DETAILED DESCRIPTION

[0083] Figure 1AA photovoltaic module 100 is depicted that is operable to measure the proximity of an object 102 disposed at a distance 103 from the photovoltaic module 100. The object 102 may be any object that can reflect light. For example, the object 102 may be an appendage (e.g., an ear, a palm, a finger) of a user of the photovoltaic module 100. The object 102 may exhibit different object surface reflectance or absorptivity between users. For example, a user's skin pigmentation may significantly affect the object surface reflectance or absorptivity of the object 102.

[0084] The optoelectronic module 100 includes an illumination module 105. The illumination module 105 includes a light emitting component 106 operable to generate emitted light 108 at a dominant wavelength. The dominant wavelength may be a wide range of wavelengths (e.g., 700 nanometers to 1000 nanometers) or may be a narrow range of wavelengths centered around a single wavelength (e.g., 650 nanometers). The dominant wavelength may be visible light (e.g., red light or white light), invisible light (e.g., infrared light or ultraviolet light), or other non-visible light (e.g., visible light pulses suitable for human observers).

[0085] The illumination module 105 may include an illumination optical assembly 110 aligned with the light emitting component 106. The light emitting component 106 is operable to generate an emission light 108 incident on the illumination optical assembly 110. The illumination optical assembly 110 may include a cover glass, a refractive lens, a diffractive lens, a microlens array, a diffuser, a spectral filter, an aperture, or a plurality of refractive lenses, diffractive lenses, microlens arrays, diffusers, spectral filters, or any combination thereof. The light emitting component 106 may include a light emitting diode, a laser diode, a vertical cavity surface emitting laser, or a plurality of light emitting diodes, laser diodes, and / or vertical cavity surface emitting lasers.

[0086] The illumination module 105 is operable to generate illumination 112 via the light emitting component 106 and in some instances, together with the illumination optical assembly 110. The illumination 112 may be homogenous, uniform illumination, structured light illumination, or may be intensity modulated as implemented in time-of-flight applications. The illumination 112 may be directed to an object 102 disposed at a distance 103 from the optoelectronic module 100.

[0087] Reflections 114 of illumination 112 are reflected from object 102. Reflections 114 can be directed to a detection module 116 disposed adjacent to illumination module 105. For example, detection module 116 can be disposed a distance of millimeters to several centimeters from illumination module 105. In some examples, illumination module 105 and detection module 116 are mounted on the same circuit board or other substrate.

[0088] The detection module 116 may include an array optical assembly 118 operable to direct the reflection 114 of the illumination 112 to the photosensitive component 120. The optical assembly 118 may include a protective glass, a refractive lens, a diffractive lens, a microlens array, a diffuser, a spectral filter, an aperture or a plurality of refractive lenses, diffractive lenses, microlens arrays, diffusers and / or spectral filters. The optical assembly 118 is characterized by a focal length 113 and an optical axis 115.

[0089] The array of photosensitive components 120 may include multiple discrete photosensitive components that are sensitive to a dominant wavelength. In addition, each photosensitive component within the array is characterized by a coordinate position. In this example, the coordinate position is defined as the linear distance between the illumination module 105 and the corresponding photosensitive component within the array of photosensitive components 120. The array of photosensitive components 120 may include photodiodes, charge coupled devices, complementary metal oxide semiconductor devices, arrays of the foregoing, or any combination thereof. The array of photosensitive components 120 may be arranged in a plane 121. The detection optical assembly 118 is aligned with the array of photosensitive components 120 so that the focal length 113 is incident on the plane 121 and the optical axis 115 is substantially perpendicular to the plane 121.

[0090] The detection module 116 is operable to collect reflections 114 of the illumination 112 reflected from the object 102. The detection module 116 is further operable to convert the collected reflections 114 into a signal via at least one of the photosensitive components within the array of photosensitive components 120. The signal (e.g., including the intensity of the reflections 114 during any given time period) is associated with a specific coordinate position of the at least one photosensitive component from which the signal was converted. The object 102 is arranged at a distance 103 from the optoelectronic module 100 by triangulating (the specific coordinate position can be associated with the distance 103), where the focal length 113 and the specific coordinate position can be used to calculate the distance 103. However, in some instances, the optoelectronic module can utilize the parallax effect without any additional calculations. By comparing Figure 1A and Figure 1B These methods are further illustrated.

[0091] exist Figure 1A In , when the object 102 is arranged at a distance 103 from the optoelectronic module 100, the reflection 114 is directed to a specific photosensitive component 122 associated with a specific coordinate position 124. Figure 1B, when the object 102 is arranged at a subsequent distance 104 from the optoelectronic module 100, the reflection 114 is directed to a subsequent photosensitive component 123 associated with a subsequent specific coordinate 125. The detection module 116 is further operable to convert the collected reflection 114 into a subsequent signal as described above. The reflection 114 is directed to a specific photosensitive component 122 associated with a specific coordinate position 124 or a subsequent photosensitive component 123 associated with a subsequent coordinate position 125 solely due to the position of the object 102 (i.e., regardless of the reflectivity of the object surface). Therefore, proximity data or other position information of the object 102 can be determined regardless of the reflectivity, absorptivity, or any other intensity-related characteristics of the object surface.

[0092] In some instances, reflection 114 may generate a particularly weak signal (e.g., low intensity) that is characterized by signal amplitude. For example, background light may reduce the relative amplitude of the signal. The extent of this effect may be different for different object positions. For example, when object 102 is at distance 103, the signal intensity may be strong enough to determine proximity data; that is, it may exceed a threshold intensity value. However, when object 102 is at distance 104, the signal amplitude may be too weak to determine proximity data. Therefore, some implementations may include an intensity modulator (not depicted). The intensity modulator is operable to modulate the intensity of the emitted light 108 generated by the light emitting component 106. For example, the intensity modulator is operable to modulate the electrical power to the light emitting component 106 so that the intensity of the emitted light 108 generated by the light emitting component 106 is modulated for different distances. That is, when object 102 is at distance 103, the power may be at a low level, and when object 102 is at distance 104, the power may be at a high level. In some examples, optoelectronic module 100 may further include additional circuitry operable to modulate the intensity of emitted light 108 generated by light emitting component 106 as a function of signal amplitude via an intensity modulator.

[0093] The above approach may be employed in instances where it is not possible to satisfactorily vary the integration time or gain of the light-sensitive component. For example, in some instances, the gain may generate a noisy signal, and the integration time may not be suitable for applications that require rapid collection of proximity data. In other instances, the output power of the light-emitting component 106 may be highly dependent on temperature; therefore, the uncertainty in the output power may be as high as 10% to 20% or more. Therefore, the ability to adjust the electrical power consumed by the light-emitting component 106 in situ (i.e., based on the magnitude of the signal strength) may allow the overall efficiency of the optoelectronic module 100 to be significantly improved.

[0094] The optoelectronic module 100 may further include a processor 126 communicatively coupled 128 to the illumination module 105, the detection module 116, and the intensity modulator. The processor 126 may include a microprocessor or other integrated circuit and may be implemented as a single processor or multiple processors. In some instances, the processor 126 may be implemented by a device such as a smart phone, a tablet, a laptop computer, or other computing device. The processor 126 is operable to process the signals generated by the array of photosensitive components 120 and may control the intensity modulator in some instances.

[0095] In some examples, the optoelectronic module 100 may further include a non-transitory computer-readable medium (not depicted) including instructions stored thereon, which when executed on the processor 126, perform the following operations, including:

[0096] When the signal amplitude is less than the threshold intensity value, increasing the intensity of the emitted light 108 generated by the light emitting component 106; and

[0097] When the signal amplitude is greater than the threshold intensity value, the intensity of the emitted light 108 generated by the light emitting component 106 is reduced.

[0098] Figure 2A An example of a method 200A of operating an example optoelectronic module 100 to measure proximity data of an object 102 independent of the reflectivity of the object surface is depicted. In an example where the optoelectronic module 100 includes a processor 126 and a non-transitory computer readable medium, the method may also be encoded into operations performed by the optoelectronic module 100. At 202, illumination 112 is directed onto an object 102 disposed at a distance 103 from the optoelectronic module 100.

[0099] At 204 , reflections 114 of illumination 112 reflected from object 102 disposed at distance 103 from optoelectronic module 100 are collected by specific light-sensitive components 122 within detection module 116 .

[0100] At 206 , the collected reflections 114 are converted into signals, wherein the signals are associated with the specific coordinate locations 124 .

[0101] At 208 , illumination 112 is directed onto object 102 at a subsequent distance 104 from optoelectronic module 100 .

[0102] At 210 , reflections 114 of illumination 112 reflected from an object 102 disposed at a subsequent distance 104 from the optoelectronic module 100 are collected by a subsequent light sensing component 123 within the detection module 116 .

[0103] At 212, the collected reflections 114 are converted into subsequent signals, wherein the subsequent signals are associated with subsequent coordinate positions 125. The subsequent signals are characterized by subsequent signal amplitudes.

[0104] At 214, the specific coordinate position 124 is associated with the distance 103 from the optoelectronic module 100. Further, in step 216, the subsequent coordinate position 125 is associated with the subsequent distance 104 from the optoelectronic module 100. The association can be achieved by triangulation, for example, using the parallax effect. Thus, proximity data is obtained from the specific coordinate position 124 and the subsequent coordinate position 125.

[0105] Figure 2B Additional operations 200B are depicted that may be performed in some embodiments. In some instances, the additional operations may improve the collection of proximity data independent of the object surface reflectivity. For example, in some instances, the following steps may improve power efficiency. At 218, when the signal amplitude is less than a threshold intensity value, the intensity of the emitted light generated by the light emitting component is increased. At 220, when the signal amplitude is greater than the threshold intensity value, the intensity of the emitted light generated by the light emitting component is reduced. These operations may occur in any order within the example method 200A.

[0106] Figure 3A and Figure 3B An optoelectronic module 100 is depicted that is operable to measure proximity and intensity related characteristics (such as peripheral blood circulation or pulse rate) independent of module displacement. Figure 3A and Figure 3B The figure shows a collection of intensity-related properties of an object 102 such as an appendage that exhibits peripheral blood flow (e.g., an ear, a finger, a hand, or even an artery or vein within the foregoing range). As blood passes through the appendage, the volume changes, such as Figure 3A Part number 107 in any time and Figure 3B 109 in FIG. 10 is represented at another arbitrary time. In this example, the volume change is accompanied by a change in absorptivity or reflectivity. For example, Figure 3B Compared with object 102, Figure 3A The object 102 in the image is less absorbent or more reflective. In addition to the change in reflectivity and absorptivity, due to the displacement of the module, Figure 3A The distance 103 at any time depicted in Figure 3B A subsequent distance 104 at another arbitrary time is depicted in FIG.

[0107] As described above, reflection 114 generates a signal in a specific photosensitive component 122, wherein the specific photosensitive component 122 is associated with a specific coordinate position 124. Similarly, reflection 114 generates a subsequent signal in a subsequent specific photosensitive component 123, wherein the specific photosensitive component 123 is associated with a subsequent specific coordinate position 125. As described above, the specific coordinate positions 124, 125 are associated with the corresponding distances 103, 104 via parallax or triangulation, and are independent of the reflectivity or absorptivity changes described above. The signal intensity (signal amplitude) reflects the changes in reflectivity / absorbency and the position of the object. Therefore, the distance determined via parallax or triangulation and the signal amplitude can be used to determine the change in signal amplitude caused only by the change in reflectivity / absorbency. In some instances, volume changes can be determined and associated with peripheral blood circulation or pulse rate.

[0108] Figure 4 An example method 400 of operating an example optoelectronic module 100 to measure proximity and intensity-related characteristics independent of module displacement is depicted. In some examples, the method 400 described below can be used to determine peripheral blood circulation or pulse rate. In examples where the optoelectronic module 100 includes a processor 126 and a non-transitory computer-readable medium, the method can be encoded into operations performed by the optoelectronic module 100.

[0109] At 402 , illumination 112 is directed onto object 102 disposed at distance 103 from optoelectronic module 100 .

[0110] At 404 , reflections 114 of illumination 112 reflected from object 102 disposed at distance 103 from optoelectronic module 100 are collected by detection module 116 .

[0111] At 406, the collected reflections 114 are converted into signals by the particular photosensitive component 122. The signals are associated with the particular coordinate locations 124. The signals are characterized by the signal amplitude.

[0112] At 408 , illumination 112 is directed onto object 102 at a subsequent distance 104 from optoelectronic module 100 .

[0113] At 410 , reflections 114 of illumination 112 reflected from object 102 disposed at a subsequent distance 104 from optoelectronic module 100 are collected by detection module 116 .

[0114] At 412, the collected reflections 114 are converted into subsequent signals by the subsequent photosensitive component 123. The subsequent signals are associated with the subsequent coordinate positions 125. The subsequent signals are characterized by the subsequent signal amplitude.

[0115] At 414 , specific coordinate location 124 is associated with distance 103 from optoelectronic module 100 .

[0116] At 416 , subsequent coordinate position 125 is associated with subsequent distance 104 from optoelectronic module 100 .

[0117] At 418 , the signal amplitude is normalized by the distance 103 , and the subsequent signal amplitude is normalized by the subsequent distance 104 .

[0118] In step 420, the normalized signal amplitude is compared to the normalized subsequent signal amplitude. In some examples, step 420 may include determining a difference in signal amplitudes. In some examples, the difference in signal amplitude and subsequent signal amplitude is associated with peripheral blood circulation.

[0119] Figure 5A and Figure 5B Another example of an optoelectronic module 500 is depicted that is operable to measure, independent of module displacement, the proximity and intensity-related characteristics (such as a user's blood oxygen level) of an object 502 disposed at a distance 503 from the optoelectronic module 500. The optoelectronic module 500 includes the same components as the example optoelectronic module 100 described above, and further includes auxiliary components that are operable to measure intensity-related characteristics (e.g., blood oxygen level).

[0120] The optoelectronic module 500 includes an illumination module 505, a light emitting component 506A operable to generate an emission light 508A of a primary wavelength. The primary wavelength may be a wide range of wavelengths (e.g., 700 nanometers to 1000 nanometers) or may be a narrow range of wavelengths centered around a single wavelength (e.g., 650 nanometers). The primary wavelength may be visible light (e.g., red light or white light), invisible light (e.g., infrared light or ultraviolet light), or other non-visible light (e.g., visible light pulses suitable for human observers). The illumination module 505 further includes an auxiliary light emitting component 506B operable to generate an auxiliary emission light 508B of an auxiliary wavelength. As described above, the auxiliary wavelength may be a wide range of wavelengths (e.g., 700 nanometers to 1000 nanometers) or may be a narrow range of wavelengths centered around a single wavelength (e.g., 650 nanometers). The primary wavelength may be visible light (e.g., blue light or green light), invisible light (e.g., infrared light or ultraviolet light), or other non-visible light (e.g., visible light pulses suitable for human observers). As will be apparent to one of ordinary skill in the art, the primary wavelength and the secondary wavelength may be configured to provide blood oxygen levels; for example, the two wavelengths may correspond to red and green light or red and infrared light.

[0121] The lighting module 505 may include an illumination optical assembly 510 aligned with the light emitting component 506A and the auxiliary light emitting component 506B. The light emitting component 506A is operable to generate an emission light 508A incident on the illumination optical assembly 510. Similarly, the light emitting component 506B is operable to generate an emission light 508B incident on the illumination optical assembly 510. The illumination optical assembly 510 may include a protective glass, a refractive lens, a diffractive lens, a microlens array, a diffuser, a spectral filter, an aperture or a plurality of refractive lenses, diffractive lenses, microlens arrays, diffusers, spectral filters or any combination thereof. The light emitting component 506A may include a light emitting diode, a laser diode, a vertical cavity surface emitting laser or a plurality of light emitting diodes, laser diodes and / or vertical cavity surface emitting lasers. Similarly, the auxiliary light emitting component 506B may include a light emitting diode, a laser diode, a vertical cavity surface emitting laser, or a plurality of light emitting diodes, laser diodes, and / or vertical cavity surface emitting lasers.

[0122] The illumination module 505 is operable to generate illumination 512 via the light emitting component 506A and in some instances, together with the illumination optical assembly 510. The illumination 512 may be homogenous, uniform illumination, structured light illumination, or may be intensity modulated as implemented in time-of-flight applications. The illumination 512 may be directed to an object 502 disposed at a distance 503 from the optoelectronic module 500. Similarly, the illumination module 505 is operable to generate auxiliary illumination 512B via the auxiliary light emitting component 506B and in some instances, together with the illumination optical assembly 510. The auxiliary illumination 512B may be homogenous, uniform illumination, structured light illumination, or may be intensity modulated as implemented in time-of-flight applications. The auxiliary illumination 512B may be directed to an object 502 disposed at a distance 503 from the optoelectronic module 500.

[0123] Reflection 514A of illumination 512A reflects from object 502. Reflection 514A can be directed to detection module 516 disposed adjacent to illumination module 505. For example, detection module 516 can be disposed a distance of millimeters to several centimeters from illumination module 505. In some examples, illumination module 505 and detection module 516 can be mounted on the same circuit board or other substrate. Similarly, auxiliary reflection 514B of illumination 512B reflects from object 502. Auxiliary reflection 514B can be directed to detection module 516.

[0124] The detection module 516 may include an optical assembly 518 operable to direct reflection 514A of illumination 512A to an array of photosensitive components 520A. Similarly, the detection optical assembly 518 may be operable to direct secondary reflection 514B of illumination 512B to a secondary array of photosensitive components 520B. The optical assembly 518 may include a protective glass, a refractive lens, a diffractive lens, a microlens array, a diffuser, a spectral filter, an aperture or a plurality of refractive lenses, diffractive lenses, microlens arrays, diffusers and / or spectral filters. The optical assembly 518 is characterized by a focal length 513 and an optical axis 515.

[0125] The array of photosensitive components 520A may include multiple discrete photosensitive components that are sensitive to the main wavelength. In addition, each photosensitive component in the array is characterized by a coordinate position. In this example, the coordinate position is defined as the linear distance between the lighting module 505 and the corresponding photosensitive component in the array of photosensitive components 520A. Similarly, the auxiliary array of photosensitive components 520B may include multiple discrete photosensitive components that are sensitive to the main wavelength. In addition, each photosensitive component in the array may be characterized by the same coordinate position as described above. The array of photosensitive components 520A and / or the auxiliary array of photosensitive components 520B may include an array of photodiodes, charge coupled devices, complementary metal oxide semiconductor devices, or any combination thereof. The array of photosensitive components 520A and the auxiliary array of photosensitive components 520B may be arranged in the same plane 521. The detection optical assembly 518 is aligned with the array of photosensitive components 520A and the auxiliary array of photosensitive components 520B so that the focal length 513 is incident on the plane 521, and the optical axis 515 is substantially perpendicular to the plane 521.

[0126] The detection module 516 is operable to collect reflections 514A of the illumination 512A reflected from the object 502. The detection module 516 is further operable to convert the collected reflections 514A into a signal by at least one of the photosensitive components within the array of photosensitive components 520A. The signal (e.g., including the intensity of the reflections 514A during any given time period) is associated with a specific coordinate position of the at least one photosensitive component from which the signal was converted. The distance 503 at which the object 502 is arranged from the optoelectronic module 500 is calculated by triangulating (the specific coordinate position can be associated with the distance 503), where the focal length 513 and the specific coordinate position can be used to calculate the distance 503. However, in some instances, the optoelectronic module can utilize the parallax effect without any additional calculations.

[0127] Similarly, the detection module 516 is operable to collect auxiliary reflections 514B of the auxiliary illumination 512B reflected from the object 502. The detection module 516 is further operable to convert the collected auxiliary reflections 514B into a signal by at least one of the photosensitive components within the auxiliary array of photosensitive components 520B. The signal (e.g., including the intensity of the auxiliary reflection 514B within any given time period) is associated with a specific coordinate position (i.e., the same specific coordinate position as described above in conjunction with the reflection 514A) of at least one photosensitive component from which the signal is converted. As described above, the object 502 is arranged to be a distance 503 from the optoelectronic module 500 by triangulating (the specific coordinate position can be associated with the distance 503), where the focal length 513 and the specific coordinate position can be used to calculate the distance 503. However, in some instances, the optoelectronic module can utilize the parallax effect without any additional calculations. By comparing Figure 5A and 5B These methods are further illustrated.

[0128] exist Figure 5A In FIG. 5 , when object 502 is arranged at a distance 503 from optoelectronic module 500, reflection 514A is directed to a specific photosensitive component 522A associated with a specific coordinate position 524. Figure 5B , when the object 502 is disposed at a subsequent distance 504 from the optoelectronic module 500, the reflection 514A is directed to a subsequent photosensitive component 523A associated with a subsequent specific coordinate 525. The detection module 516 is further operable to convert the collected reflection 514A into a subsequent signal as described above. The reflection 514A is directed to a specific photosensitive component 522A associated with a specific coordinate position 524 or a subsequent photosensitive component 523A associated with a subsequent coordinate position 525 solely due to the position of the object 502 (i.e., regardless of the reflectivity of the object surface). Therefore, proximity data or other position information of the object 502 can be determined regardless of the reflectivity, absorptivity, or any other intensity-related characteristics of the object surface.

[0129] Similarly, in Figure 5A In FIG. 5 , when the object 502 is arranged at a distance 503 from the optoelectronic module 500, the auxiliary reflection 514B is directed to a specific auxiliary photosensitive component 522B associated with a specific coordinate position 524. Figure 5B, when the object 502 is arranged to be a subsequent distance 504 from the optoelectronic module 500, the auxiliary reflection 514B is directed to the subsequent auxiliary photosensitive component 523B associated with the subsequent specific coordinate 525. The detection module 516 is further operable to convert the collected auxiliary reflection 514B into a subsequent auxiliary signal as described above. The auxiliary reflection 514B is directed to the specific auxiliary photosensitive component 522B associated with the specific coordinate position 524 or the subsequent auxiliary photosensitive component 523B associated with the subsequent coordinate position 525 only due to the position of the object 502 (i.e., regardless of the reflectivity of the object surface). Therefore, as described above, the proximity data or other position information of the object 502 can be determined regardless of the reflectivity, absorptivity or any other intensity-related characteristics of the object surface. In some instances, the main wavelength or the auxiliary wavelength may be more effective for measuring the distance or proximity of the object 502. For example, in some instances, the object 502 may substantially absorb the main wavelength, but may substantially reflect the auxiliary wavelength. Further applications of the optoelectronic device 500 are described below, including measuring the blood oxygen level of a user.

[0130] Figure 6 An example of a method 600 of operating an optoelectronic module 500 to measure proximity and intensity-related characteristics independent of module displacement is depicted. In some examples, the example method 600 described below can be used for pulse oximetry. In examples where the optoelectronic module 500 includes a processor 526 and a non-transitory computer-readable medium, the method can also be encoded into operations performed by the optoelectronic module 500.

[0131] At 602 , both illumination 512A and auxiliary illumination 512 are directed toward object 502 disposed at distance 503 from optoelectronic module 500 .

[0132] At 604 , reflections 514A of illumination 512A reflected from object 502 disposed at distance 503 from optoelectronic module 500 are collected by detection assembly 516 and converted into signals by specific light-sensitive components 522A. The signals are associated with coordinate locations 523 .

[0133] At 606 , reflection 514B of auxiliary illumination 512B reflected from object 502 disposed at distance 503 from optoelectronic module 500 is collected by detection assembly 516 and converted into auxiliary signals by auxiliary light sensing component 522B. The auxiliary signals are associated with coordinate position 524 .

[0134] At 608 , illumination 512A and auxiliary illumination 512B are directed onto object 502 at a subsequent distance 504 from optoelectronic module 500 .

[0135] At 610, reflections 514A of illumination 512A reflected from an object 502 disposed at a subsequent distance 504 from the optoelectronic module 500 are collected by the detection module 516 and converted into a subsequent signal by a specific photosensitive component 523A. The subsequent signal is associated with a subsequent coordinate position 525, and the subsequent signal is characterized by a subsequent signal amplitude. Similarly, at 612, reflections 514B of auxiliary illumination 512B reflected from an object 502 disposed at a subsequent distance 504 from the optoelectronic module 500 are collected by the detection module 516 and converted into a subsequent auxiliary signal by a subsequent auxiliary photosensitive component 523B. The subsequent signal is associated with a subsequent coordinate position 525, and the subsequent signal is characterized by a subsequent auxiliary signal amplitude.

[0136] At 614, reflections 514B of auxiliary illumination 512B are reflected from object 502 disposed at a subsequent distance 504 from the optoelectronic module and the collected reflections are converted into subsequent auxiliary signals that can be associated with subsequent coordinate positions 525 and characterized by subsequent auxiliary signal amplitudes.

[0137] At 616 , coordinate location 524 is associated with distance 503 from optoelectronic module 500 .

[0138] At 618 , subsequent coordinate position 525 is associated with subsequent distance 504 from optoelectronic module 500 .

[0139] At 620 , the signal amplitude is normalized by the distance 503 , and the subsequent signal amplitude is normalized by the subsequent distance 504 .

[0140] At 622 , the auxiliary signal amplitude is normalized by the distance 503 , and the subsequent auxiliary signal amplitude is normalized by the subsequent distance 504 .

[0141] At 624, the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude are compared to one another.

[0142] At 626, comparing the signal amplitudes as described above may include determining a difference between the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude. In some examples, the difference in signal amplitudes is associated with blood oxygen level.

[0143] Other modifications may be made to the foregoing implementations, and features described above in different implementations may be combined in the same implementation. Therefore, other implementations are within the scope of the claims.

Claims

1. A photovoltaic module, comprising: Lighting module; a detection module arranged adjacent to the lighting module; as well as one or more processors communicatively coupled to the illumination module and the detection module, the optoelectronic module further comprising a non-transitory computer-readable medium including instructions stored thereon; Wherein, the lighting module includes a light-emitting component and a lighting optical component, The light emitting component is operable to generate emitted light incident on the illumination optical assembly, the emitted light being characterized by a dominant wavelength, The detection module comprises a detection optical assembly and an array of photosensitive components arranged in a plane, wherein the array comprises a plurality of photosensitive components, each photosensitive component is characterized by a coordinate position, each photosensitive component is sensitive to the dominant wavelength, The detection optical assembly is characterized by a focal length and an optical axis, wherein the detection optical assembly is aligned with the array of photosensitive components so that the focal length is incident on the plane and the optical axis is substantially perpendicular to the plane, The emitted light incident on the illumination optical assembly produces illumination together with the illumination optical assembly, the illumination module being operable to direct the illumination to an object disposed at a distance from the optoelectronic module, and The detection module is operable to collect reflections of illumination reflected from the object, and is further operable to convert the collected reflections into a signal by at least one of the photosensitive components within the array of photosensitive components, the signal being associated with a specific coordinate position of the at least one photosensitive component from which the signal is converted, wherein the specific coordinate position is associated with the distance at which the object is arranged from the optoelectronic module, wherein the signal is characterized by signal amplitude; Wherein, the light emitting module further comprises an auxiliary light emitting component; and The auxiliary light emitting component is operable to generate auxiliary emission light incident on the illumination optical assembly, the auxiliary emission light being characterized by an auxiliary wavelength; The auxiliary emission light incident on the illumination optical component generates auxiliary illumination together with the illumination optical component; the lighting module being operable to direct the auxiliary lighting toward the object at the distance from the photovoltaic module; The optoelectronic module further comprises an auxiliary array of photosensitive components arranged in the plane, the auxiliary array comprising a plurality of auxiliary photosensitive components, each auxiliary photosensitive component being characterized by the coordinate position, and each auxiliary photosensitive component being sensitive to the auxiliary wavelength; wherein the detection module is operable to collect reflections of the auxiliary illumination reflected from the object, and is further operable to convert the collected reflections into an auxiliary signal by at least one of the auxiliary photosensitive components within the auxiliary array of photosensitive components, the auxiliary signal being associated with a specific coordinate position of the at least one auxiliary photosensitive component, the auxiliary signal being converted from the at least one auxiliary photosensitive component, wherein the specific coordinate position is associated with the distance at which the object is arranged from the optoelectronic module, wherein the auxiliary signal is characterized by an auxiliary signal amplitude; Wherein, when the instruction is executed by the one or more processors, the following operations are performed, including: directing the illumination onto the object disposed at the distance from the photovoltaic module, and directing the auxiliary illumination onto the object disposed at the distance from the photovoltaic module; collecting the reflections of the illumination reflected from the object disposed at the distance from the optoelectronic module and converting the collected reflections into the signal, the signal being associated with the coordinate position; collecting the reflections of the auxiliary lighting reflected from the object arranged at the distance from the optoelectronic module and converting the collected reflections into the auxiliary signal, the auxiliary signal being associated with the coordinate position; directing the illumination onto the object at a subsequent distance from the photovoltaic module and directing the auxiliary illumination onto the object at a subsequent distance from the photovoltaic module; collecting reflections of the illumination reflected from the object disposed at the subsequent distance from the optoelectronic module; and converting the collected reflections into a subsequent signal, the subsequent signal being associated with a subsequent coordinate position, the subsequent signal being characterized by a subsequent signal amplitude; collecting reflections of the auxiliary illumination reflected from the object disposed at the subsequent distance from the optoelectronic module; and converting the collected reflections into a subsequent auxiliary signal, the subsequent auxiliary signal being associated with a subsequent coordinate position, the subsequent auxiliary signal being characterized by a subsequent auxiliary signal amplitude; associating the coordinate position with the distance from the optoelectronic module and associating the subsequent coordinate position with the subsequent distance from the optoelectronic module; normalizing the signal amplitude by the distance, and normalizing the subsequent signal amplitude by the subsequent distance; normalizing the auxiliary signal amplitude by the distance, and normalizing the subsequent auxiliary signal amplitude by the subsequent distance; and comparing the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude; wherein comparing the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude comprises determining a difference between the signal amplitudes; and The difference between the signal amplitudes is associated with the blood oxygen level. 2 . The optoelectronic module of claim 1 , further comprising an intensity modulator operable to modulate the intensity of the emitted light generated by the light emitting component.

3. The photovoltaic module according to claim 2, wherein: The intensity modulator is operable to modulate electrical power to the light emitting component such that the intensity of the emitted light generated by the light emitting component is modulated.

4. The photovoltaic module according to claim 2 or claim 3, further comprising: Circuitry operable to modulate the intensity of the emitted light generated by the light emitting component as a function of the signal amplitude via the intensity modulator.

5. The photovoltaic module according to claim 2, wherein: The intensity modulator is operable to modulate the intensity of the auxiliary emission light generated by the auxiliary lighting component.

6. The photovoltaic module according to claim 5, wherein: The intensity modulator is operable to modulate electrical power to the auxiliary lighting component such that the intensity of the auxiliary emission light generated by the auxiliary lighting component is modulated.

7. The photovoltaic module according to claim 4, wherein: The circuit is operable to modulate the intensity of the auxiliary emission light generated by the auxiliary lighting component according to the auxiliary signal amplitude via the intensity modulator.

8. The photovoltaic module according to claim 7, wherein: When the auxiliary signal amplitude is less than a threshold intensity value, the intensity of the auxiliary emission light generated by the auxiliary lighting component is increased.

9. The photovoltaic module according to claim 6, wherein: When the auxiliary signal amplitude is greater than a threshold intensity value, the intensity of the emitted light generated by the auxiliary lighting component is reduced.

10. The photovoltaic module according to claim 4, wherein: The one or more processors are further communicatively coupled to the intensity modulator. When the instructions are executed by the one or more processors, the following operations are further performed, including: When the signal amplitude is less than a threshold intensity value, increasing the intensity of the emitted light generated by the light emitting component; and When the signal amplitude is greater than a threshold intensity value, the intensity of the emitted light generated by the light emitting component is reduced.

11. The photovoltaic module according to claim 2, wherein: The one or more processors are further communicatively coupled to the intensity modulator. When the instructions are executed by the one or more processors, the following operations are further performed, including: increasing the intensity of the emitted light generated by the light emitting component when the signal amplitude is less than a threshold intensity value; reducing the intensity of the emitted light generated by the light emitting component when the signal amplitude is greater than a threshold intensity value; When the auxiliary signal amplitude is less than a threshold intensity value, increasing the intensity of the auxiliary emission light generated by the auxiliary lighting component; and When the auxiliary signal amplitude is greater than a threshold intensity value, the intensity of the auxiliary emission light generated by the auxiliary lighting component is reduced.

12. The photovoltaic module according to claim 1, wherein: The difference between the signal amplitude and the subsequent signal amplitude is associated with peripheral blood circulation.

13. A method of operating a photovoltaic module, the method comprising: directing illumination onto an object disposed at a distance from the photovoltaic module; collecting reflections of the illumination reflected from the object disposed at the distance from the photovoltaic module; converting the collected reflections into signals associated with specific coordinate locations; directing the illumination onto the object at a subsequent distance from the photovoltaic module; collecting reflections of the illumination reflected from the object disposed at the subsequent distance from the optoelectronic module; converting the collected reflections into a subsequent signal associated with a subsequent coordinate position, the subsequent signal being characterized by a subsequent signal amplitude; associating the specific coordinate location with the distance from the optoelectronic module; associating the subsequent coordinate position with the subsequent distance from the optoelectronic module; normalizing the signal amplitude by the distance, and normalizing the subsequent signal amplitude by the subsequent distance; and comparing the normalized signal amplitude and the normalized subsequent signal amplitude; directing auxiliary lighting toward the object at the distance from the photovoltaic module; collecting reflections of the auxiliary lighting reflected from the object at the distance from the optoelectronic module and converting the collected reflections into auxiliary signals, the auxiliary signals being associated with the coordinate positions; directing the auxiliary lighting onto the object at a subsequent distance from the photovoltaic module; collecting reflections of the auxiliary illumination reflected from the object at the subsequent distance from the optoelectronic module; and converting the collected reflections into a subsequent auxiliary signal, the subsequent auxiliary signal being associated with a subsequent coordinate position; the subsequent auxiliary signal being characterized by a subsequent auxiliary signal amplitude; normalizing the auxiliary signal amplitude by the distance, and normalizing the subsequent auxiliary signal amplitude according to the subsequent distance; as well as comparing the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude; wherein comparing the normalized signal amplitude, the normalized subsequent signal amplitude, the normalized auxiliary signal amplitude, and the normalized subsequent auxiliary signal amplitude comprises determining a difference between the signal amplitudes; and The difference between the signal amplitudes is associated with the blood oxygen level.

14. The method according to claim 13, further comprising: Peripheral blood circulation is associated with a difference between the signal amplitude and the subsequent signal amplitude.

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