Head-mounted device and sensing method

Abstract

The invention provides a head-mounted device and a sensing method. The head-mounted equipment comprises a pair of frames, a beam part, a pair of nose pads, a sensing device and a processing circuit. The sensing device comprises a first light source and a first light sensor which are arranged in a first arrangement mode, and a second light source and a second light sensor which are arranged in a second arrangement mode. The processing circuit controls the first light source and the second light source to respectively emit first test light and second test light at different time sequences; receiving a first sensing signal generated by the first light sensor, a second sensing signal generated by the second light sensor, a third sensing signal generated by the first light sensor and a fourth sensing signal generated by the second light sensor; determining whether the head-mounted device is in a wearing state according to the first to fourth sensing signals; and in response to determining that the head-mounted device is in the wearing state, acquiring the heart rate of the user by processing the first to fourth sensing signals.

Description

Technical Field

[0001] The present invention relates to a wearable device and method, and in particular to a head-mounted device and a sensing method, which can avoid false detection when the head-mounted device is not worn. Background Art

[0002] Photoplethysmogram (PPG) signals are optically obtained plethysmograms that indicate changes in blood volume in the microvascular bed of tissue. PPG signals are typically obtained using a pulse oximeter, which shines light on the skin to measure changes in light absorption.

[0003] In addition, existing wearable products can measure heart rate through PPG signals. However, when wearable products are not worn, heart rate often gets mismeasured. Even when wearable products are worn, inaccurate measurements may occur due to incomplete wearing.

[0004] For existing smart glasses, the problems of mismeasurement and inaccurate measurement may also occur, which needs to be solved urgently. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a head mounted device to avoid misdetection in a non-wearing state in view of the deficiencies in the prior art.

[0006] In order to solve the above-mentioned technical problems, one of the technical solutions adopted by the present invention is to provide a head-mounted device, characterized in that the head-mounted device includes: a pair of frames and a beam connected between the pair of frames; a pair of nose pads, respectively connected to the pair of frames; a sensing device, including: a first light source and a first light sensor, arranged in one of the nose pads of the pair of nose pads in a first arrangement; and a second light source and a second light sensor, arranged in the other of the nose pads of the pair of nose pads in a second arrangement, wherein the first arrangement is opposite to the second arrangement; and a processing circuit, electrically connected to the sensing device, wherein the processing circuit is configured to: control the first light source and the second light source to emit first test light and a second test light; receiving a first sensing signal generated by the first light sensor corresponding to the second test light; receiving a second sensing signal generated by the second light sensor corresponding to the first test light; receiving a third sensing signal generated by the first light sensor corresponding to the first test light; receiving a fourth sensing signal generated by the second light sensor corresponding to the second test light; determining whether the head-mounted device is in a wearing state according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and in response to determining that the head-mounted device is in a wearing state, obtaining the user's heart rate by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0007] Optionally, when the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

[0008] Optionally, in the step of determining whether the head-mounted device is in the wearing state, the processing circuit is also configured to: obtain a first light intensity, a second light intensity, a third light intensity and a fourth light intensity from the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal, respectively; and determine whether the head-mounted device is in the wearing state based on at least two of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity.

[0009] Optionally, in response to the first light intensity or the second light intensity being greater than a first threshold and the third light intensity or the fourth light intensity being less than a second threshold, the processing circuit is configured to determine that the head-mounted device is not in the wearing state.

[0010] Optionally, in response to the first light intensity increasing by a first value greater than a third threshold and the third light intensity decreasing by a second value greater than a fourth threshold, the processing circuit is configured to determine that the head-mounted device is not in the wearing state; or in response to the second light intensity increasing by a third value greater than the third threshold and the fourth light intensity decreasing by a fourth value greater than a fourth threshold, the processing circuit is configured to determine that the head-mounted device is not in the wearing state.

[0011] Optionally, in response to the first light intensity being lower than the third light intensity by a fifth value greater than a fifth threshold, and in response to the second light intensity being lower than the fourth light intensity by a sixth value greater than a sixth threshold, the processing circuit is configured to determine that the head-mounted device is in the wearing state.

[0012] Optionally, a first direct path between the first light sensor and the first light source is blocked by a portion of one of the pair of nose pads, and a second direct path between the second light sensor and the second light source is blocked by a portion of the other of the pair of nose pads.

[0013] Optionally, in the step of acquiring the heart rate of the user by processing the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal, the processing circuit is further configured to: acquire a first perfusion index, a second perfusion index, a third perfusion index and a fourth perfusion index according to the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal, respectively; and acquire the heart rate of the user by performing a heart rate calculation procedure on the one of the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index.

[0014] Optionally, each of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index is obtained according to a pulsating signal and a non-pulsating signal of each of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0015] Optionally, the heart rate calculation program includes: recording the light intensity of one of the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index as a photoplethysmography signal; and calculating and obtaining the user's heart rate from the photoplethysmography signal.

[0016] In order to solve the above-mentioned technical problems, one of the technical solutions adopted by the present invention is to provide a sensing method, characterized in that the sensing method is applicable to a head-mounted device, the head-mounted device includes a pair of frames, a beam portion connected between the pair of frames, and a pair of nose pads respectively connected to the pair of frames, the sensing method includes: providing a sensing device, including: a first light source and a first light sensor, which are arranged in one of the nose pads of the pair of nose pads in a first arrangement; and a second light source and a second light sensor, which are arranged in the other of the nose pads of the pair of nose pads in a second arrangement, wherein the first arrangement is opposite to the second arrangement; and configuring a processing circuit to: control the first light source and the second light source to emit light respectively at different time sequences A first test light and a second test light; receiving a first sensing signal generated by the first light sensor corresponding to the second test light; receiving a second sensing signal generated by the second light sensor corresponding to the first test light; receiving a third sensing signal generated by the first light sensor corresponding to the first test light; receiving a fourth sensing signal generated by the second light sensor corresponding to the second test light; determining whether the head-mounted device is in a wearing state according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and in response to determining that the head-mounted device is in a wearing state, obtaining the user's heart rate by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0017] Optionally, in the sensing method, when the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

[0018] Optionally, in the sensing method, the step of determining whether the head-mounted device is in the wearing state also includes: obtaining a first light intensity, a second light intensity, a third light intensity and a fourth light intensity from the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal, respectively; and determining whether the head-mounted device is in the wearing state based on at least two of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity.

[0019] Optionally, in the sensing method, in response to the first light intensity or the second light intensity being greater than a first threshold and the third light intensity or the fourth light intensity being less than a second threshold, the processing circuit is configured to determine that the head-mounted device is not in the wearing state.

[0020] Optionally, in the sensing method, when the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

[0021] Optionally, in the sensing method, the sensing method further includes: in response to the first light intensity being less than the second light intensity and the third light intensity being less than the fourth light intensity, configuring the processing circuit to determine that the head-mounted device is not in the wearing state.

[0022] Optionally, in the sensing method, a first direct path between the first light sensor and the first light source is blocked by a portion of one of the pair of nose pads, and a second direct path between the second light sensor and the second light source is blocked by a portion of the other of the pair of nose pads.

[0023] Optionally, in the sensing method, the step of acquiring the heart rate of the user by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal also includes: acquiring a first perfusion index, a second perfusion index, a third perfusion index and a fourth perfusion index respectively according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and acquiring the heart rate of the user by performing a heart rate calculation procedure on the one of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index.

[0024] Optionally, in the sensing method, each of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index is obtained based on the pulsating signal and the non-pulsating signal of each of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0025] Optionally, in the sensing method, the heart rate calculation procedure includes: recording the light intensity of one of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index as a photoplethysmography signal; and calculating and obtaining the user's heart rate from the photoplethysmography signal.

[0026] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 4 is a functional block diagram of a head mounted device according to an embodiment of the present invention.

[0028] Figure 2 A perspective view of a head mounted device according to an embodiment of the present invention.

[0029] Figure 3 Flow chart of a sensing method according to an embodiment of the present invention.

[0030] Figure 4 FIG. 4 is a schematic diagram of the operation of a sensor device in a head mounted device in a worn state according to an embodiment of the present invention.

[0031] Figure 5 FIG. 4 is a schematic diagram of the operation of a sensor device in a head mounted device in a non-wearing state according to an embodiment of the present invention.

[0032] Figure 6 This is a detailed flowchart of step S32.

[0033] Figure 7 This is a detailed flowchart of step S34. DETAILED DESCRIPTION

[0034] The following is an explanation of the implementation methods of the "head-mounted device and sensing method" disclosed in the present invention through specific examples. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted in actual size. It is stated in advance. The following implementation methods will further explain the relevant technical content of the present invention in detail, but the disclosed content is not intended to limit the scope of protection of the present invention. In addition, the term "or" used in this article may include any one or more combinations of the associated listed items depending on the actual situation.

[0035] Figure 1 is a functional block diagram of a head mounted device according to an embodiment of the present invention, Figure 2 1 is a perspective view of a head mounted device according to an embodiment of the present invention. Figure 1 and Figure 2 An embodiment of the present invention provides a head mounted device 1, which may be a pair of sensor glasses and includes a pair of frames 10, a beam portion 12, a pair of nose pads 14, a sensor device 16 and a processing circuit 18.

[0036] exist Figure 2 In the embodiment, the head mounted device 1 adopts a structure similar to ordinary glasses commonly used for vision correction. The pair of frames 10 may also be referred to as spectacle frames, in which a pair of glass lenses 11 are embedded, and the beam 12 may be connected between the pair of frames 10.

[0037] The head mounted device 1 is also provided with a pair of temples 101 respectively connected to the pair of frames 10. The pair of nose pads 14 are respectively provided on one side of each frame 10, so that when the user wears the head mounted device 1 (i.e., the head mounted device 1 is in a wearing state), the pair of nose pads 14 can be against the user's nose, thereby allowing the head mounted device 1 to be stably placed on the user's nose. In some embodiments, a pair of pad arms can be selectively provided to connect the pair of nose pads 14 to the frame 10, but the present invention is not limited thereto, and the pair of nose pads 14 can be directly connected to the frame 10 respectively.

[0038] like Figure 1 and Figure 2As shown, the sensing device 16 may include a first light source 160 and a first light sensor 162 arranged in a first arrangement in one of the pair of nose pads 14. For example, the first light source 160 and the first light sensor 162 may be arranged in the left nose pad 14, and the first arrangement means that the first light sensor 162 is located above the first light source 160, that is, the height of the first light sensor 162 is greater than the height of the first light source 160, especially when the head mounted device 1 is worn.

[0039] In addition, the sensor device 16 may further include a second light source 164 and a second light sensor 166, which are arranged in the other of the pair of nose pads 14 in a second arrangement opposite to the first arrangement. For example, the second light source 164 and the second light sensor 166 may be arranged in the right nose pad 14, and the second arrangement means that the second light source 164 is located above the second light sensor 166, that is, the height of the second light source 164 is greater than the height of the second light sensor 166, especially when the head-mounted device 1 is worn. It should be noted that the first arrangement is opposite to the second arrangement, which means that when the head-mounted device 1 (sensing glasses) is worn, the arrangement order of the first light source 160 and the first light sensor 162 along the gravity direction is opposite to the arrangement order of the second light source 164 and the second light sensor 166 along the gravity direction.

[0040] The first light source 160 and the second light source 164 are, for example, light emitting diodes (LEDs), and the first light sensor 162 and the second light sensor 166 are, for example, photodiodes (PDs). In some embodiments, the first light source 160 and the first light sensor 162 can be integrated into a sensor circuit with a built-in LED, and the same is true for the second light source 160 and the second light sensor 162.

[0041] In some embodiments, a signal amplification circuit may be provided for the first light sensor 162 and the second light sensor 166 to amplify electrical signals therefrom, and light guides may be disposed adjacent to the first light source 160 and the second light source 164 , respectively, to guide emitted light in a desired direction.

[0042] The processing circuit 18 is electrically connected to the sensing device, more specifically, to the first light source 160, the first light sensor 162, the second light source 164, and the second light sensor 166. The processing circuit 18 may include one or more control circuits, such as one or more dedicated controllers and / or one or more programmable general-purpose microprocessors. The processing circuit 18 may be configured to activate the light sensor and light source of the sensing device 16, coordinate the operation of the light sensor and the light source, and receive output signals from the light sensor and / or any additional sensor included in the head mounted device 1.

[0043] In some embodiments, processing circuitry 18 may include at least one memory element which may include, for example, local memory employed during actual execution of program code, bulk storage, and cache memory which may temporarily store at least some program code.

[0044] In order to reduce the cross-interference between the first light source 160 and the first light sensor 162, the direct path between the first light sensor 162 and the first light source 160 may be blocked by a portion of the left nose pad 14, for example, by a partition 140 disposed between the first light sensor 162 and the first light source 160. Similarly, another direct path between the second light source 164 and the second light sensor 166 may be blocked by a portion of the right nose pad 14, for example, by another partition 140 disposed between the second light sensor 166 and the second light source 164, to reduce the cross-interference between the second light source 164 and the second light sensor 166.

[0045] See also Figure 3 , Figure 3 FIG. 1 is a flow chart of a sensing method according to an embodiment of the present invention. In another aspect, the present invention provides a sensing method applicable to the head mounted device 1. Figure 3 As shown, the sensing method may include configuring the processing circuit to perform the following steps:

[0046] Step S30: Control the first light source and the second light source to respectively emit the first test light and the second test light at different time sequences.

[0047] In this step, in order to clearly distinguish the source of the test light, the first test light and the second test light are controlled to be emitted at different time points. Figure 4 and Figure 5 , Figure 4 is a schematic diagram of the operation of the sensor device in the head mounted device in the wearing state according to an embodiment of the present invention, Figure 5 FIG. 4 is a schematic diagram of the operation of a sensor device in a head mounted device in a non-wearing state according to an embodiment of the present invention.

[0048] like Figure 4 and Figure 5As shown, the first test light emitted by the first light source 160 at the first time point can be received by the second light sensor 166 through the second path P2, and may or may not be received by the first light sensor 162 through the third path P3, depending on whether the user's nose is located between the pair of nose pads 14. More specifically, when the head mounted device 1 is in a wearing state, the first test light emitted by the first light source 160 at the first time point can be received by the first light sensor 162 through the third path P3 due to being reflected by the user's nose. Otherwise, the first light sensor 162 may not receive the first test light, or the first light sensor 162 may only receive a very small portion of the first test light.

[0049] Similarly, the second test light emitted by the second light source 160 at the second time point may be received by the first light sensor 162 through the first path P1 and may or may not be received by the second light sensor 166 through the fourth path P4 depending on whether the user's nose is located between the pair of nose pads 14 .

[0050] It should be noted that a light control film, for example, a view control film (VCF), can be provided on the light output side of each of the first light source 160 and the second light source 164, so as to control a first ratio of the amount of light emitted by the first light source 160 to the first light sensor 162 and the amount of light emitted to the second light sensor 166, and to control a second ratio of the amount of light emitted by the second light source 164 to the first light sensor 162 and the amount of light emitted to the second light sensor 166.

[0051] For example, since the intensities of the first test light emitted along the second path P2 and the second test light emitted along the first path P1 are high enough to penetrate the bridge of the nose, most of the light emitted from the first light source 160 can be allocated to the direct path between the first light sensor 162 and the first light source 160, and most of the light emitted from the second light source 164 can be allocated to the direct path between the second light sensor 166 and the second light source 164.

[0052] More specifically, with the direct path between the first light sensor 162 and the first light source 160 as a reference angle of 0 degrees, the light control film can be disposed on the light output side of the first light source 160 to control the light intensity of the first light source 160 within the inner angle range (e.g., +5 to -5 degrees) to be stronger than the light intensity within the outer angle range (e.g., +5 to +25 degrees and -5 to -25 degrees).

[0053] Therefore, the sensing method may enter step S31: receiving a first sensing signal, a second sensing signal, a third sensing signal, and a fourth sensing signal from the first light sensor and the second light sensor respectively.

[0054] In step S31, the first light sensor 162 generates a first sensing signal corresponding to the second test light, the second light sensor 166 generates a second sensing signal corresponding to the first test light, the first light sensor 162 generates a third sensing signal corresponding to the first test light, and the second light sensor 166 generates a fourth sensing signal corresponding to the second test light.

[0055] In addition, when the user wears the sensor glasses on the user's nose (i.e., in a wearing state), the first light sensor 162 receives the second test light passing through the user's nose and generates a first sensing signal, the second light sensor 166 receives the first test light passing through the user's nose and generates a second sensing signal, the first light sensor 162 receives the first test light reflected from the user's nose and generates a third sensing signal, and the second light sensor 166 receives the second test light reflected from the user's nose and generates a fourth sensing signal.

[0056] The difference is that when the user does not wear the sensor glasses on the nose (i.e., in the non-wearing state), since the first test light along the second path P2 and the second test light along the first path P1 pass through the air, the light intensity corresponding to the first sensor signal and the second sensor signal becomes stronger than the light intensity of the first sensor signal and the second sensor signal generated in the wearing state of the head mounted device 1. However, since the first test light and the second test light are not reflected by the user's nose, the light intensity corresponding to the third sensor signal and the fourth sensor signal becomes extremely small (even close to 0).

[0057] Therefore, a detection table for wearing detection may be established by using the changes in the intensities corresponding to the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal.

[0058] The sensing method enters step S32: determining whether the sensing glasses are in a wearing state according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0059] See also Figure 6 , Figure 6 is a detailed flow chart of step S32. Figure 6 As shown, step S32 may include the following steps:

[0060] Step S320: Obtain a first light intensity, a second light intensity, a third light intensity, and a fourth light intensity from the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal, respectively.

[0061] For example, a detection table for the wearing state and non-wearing state of the head mounted device 1 can be pre-established by measuring the light intensities sensed by the first light sensor 162 and the second light sensor 166 at different time points when the first test light and the second test light are emitted respectively.

[0062] Therefore, the detection table can be established as shown in Table 1 below:

[0063] Table 1:

[0064]

[0065] It can be seen from Table 1 that wearing detection can be performed based on at least two of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity.

[0066] Step S321: Determine whether the head mounted device is in a wearing state according to at least two of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity.

[0067] In one example, when the first light intensity or the second light intensity is greater than a first threshold, and the third light intensity or the fourth light intensity is less than a second threshold, it can be determined that the head mounted device is in a [ a 1] It should be noted that the first threshold and the second threshold can be determined according to the light intensity measured when establishing the detection table.

[0068] In another example, the first light intensity, the second light intensity, the third light intensity and the fourth light intensity are monitored in real time, and when the first light intensity increases by a first value greater than a third threshold and the third intensity decreases by a second value greater than a fourth threshold, it can be determined that the head-mounted device is in a non-wearing state.

[0069] Similarly, when the second light intensity increases by a third value greater than the third threshold and the fourth light intensity decreases by a fourth value greater than the fourth threshold, the sensing method may enter step S33 to determine that the head mounted device is not in a wearing state. It should be noted that the third threshold and the fourth threshold may be determined based on the light intensity measured in the detection table.

[0070] In another example, the difference between two of the first light intensity, the second light intensity, the third light intensity, and the fourth light intensity is monitored in real time for wearing detection. When the first light intensity is smaller than the third light intensity by a fifth value greater than a fifth threshold, and when the second light intensity is smaller than the fourth light intensity by a sixth value greater than a sixth threshold, the processing circuit is configured to determine that the head mounted device is in a wearing state, and the sensing method may then proceed to step S33, such as Figure 3 It should be noted that the fifth threshold value and the sixth threshold value can be determined according to the light intensity measured when establishing the detection table.

[0071] Therefore, wearing detection can be accurately performed based on at least two of the first light intensity, the second light intensity, the third light intensity and the fourth light intensity, thereby solving the problems of misdetection and inaccurate measurement in the prior art.

[0072] like Figure 3 As shown, in response to determining that the head mounted device is in a wearing state, the sensing method enters step S34: acquiring the user's heart rate by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

[0073] According to some embodiments of the present disclosure, the user's heart rate may be directly or indirectly measured or derived through biological parameters such as a photoplethysmogram (PPG) waveform and a perfusion index.

[0074] See also Figure 7 , Figure 7 is a detailed flow chart of step S34. Figure 7 As shown, step S34 may include the following steps:

[0075] Step S340: Obtaining a first perfusion index, a second perfusion index, a third perfusion index, and a fourth perfusion index according to the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal, respectively.

[0076] In step S340, each of the first perfusion index, the second perfusion index, the third perfusion index, and the fourth perfusion index may be obtained according to the pulsatile signal and the non-pulsatile signal of each of the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal.

[0077] Specifically, the perfusion index can be calculated according to the following formula:

[0078] Perfusion Index (PI) = AC / DC*100%;

[0079] Among them, AC represents a pulsating signal, and DC represents a non-pulsating signal. More specifically, PI is a ratio of pulsating blood flow to non-pulsating static blood flow in the user's peripheral tissue (e.g., nose), and the pulsating blood flow and the non-pulsating static blood flow are associated with the pulsating signal and the non-pulsating signal, respectively.

[0080] Step S341: Obtain the user's heart rate by performing a heart rate calculation procedure on the one of the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index.

[0081] In this step, a higher perfusion index tends to lead to a better heart rate measurement. Therefore, the one of the first to fourth sensing signals corresponding to the largest one of the first to fourth perfusion indexes is selected to calculate the user's heart rate, thereby achieving high-precision heart rate measurement.

[0082] More specifically, the light intensity of one of the first to fourth sensing signals corresponding to the largest one of the first to fourth perfusion indexes is recorded as a photoplethysmography (PPG) signal, which can be used to calculate and obtain the user's heart rate.

[0083] In some embodiments, the accuracy of the heart rate obtained from the largest one of the first to fourth perfusion indices may be estimated. More specifically, the largest one of the perfusion indices may be compared with the second largest one of the perfusion indices to estimate the accuracy. That is, when the larger two of the perfusion indices are equal to or similar to each other (e.g., the difference between them is less than a threshold), it can be ensured that the heart rate obtained from the largest one of the perfusion indices is highly accurate.

[0084] Please refer again Figure 1 According to some exemplary embodiments, a notification may be provided to the user in response to the head mounted device being in a wearing state and / or a non-wearing state. For example, the notification may be provided by at least one selected from a vibration device 1, a speaker 15, a display unit 17 (e.g., a projector through a lens), and a notification light source 19, and these devices may be selectively included in the head mounted device 1.

[0085] In some embodiments, the head-mounted device 1 can communicate with various types of electronic devices, such as smart phones, smart watches, smart glasses, tablets, personal computers, etc., through a wireless communication circuit 13 electrically connected to the processing circuit 18 to provide notifications or detection results of wearing detection and / or heart rate.

[0086] In addition, since the first test light and the second test light emitted at different times can penetrate the user's nose and / or be reflected by the user's nose, it is conceivable that another detection table can be established to perform facial expression recognition. For example, the first sensor signal, the second sensor signal, the third sensor signal, and the fourth sensor signal can be recorded for different facial expressions, and feature extraction is performed on the recorded sensor signals to obtain the corresponding relationship between the extracted features and the specific facial expressions, thereby establishing a detection table for facial expression recognition.

[0087] [Beneficial Effects of Embodiments]

[0088] In summary, the head-mounted device and sensing method provided by the present invention, since the two light source-sensor pairs adopt two opposite arrangements, can accurately perform wearing detection based on at least two of the first light intensity to the fourth light intensity, which can solve the problems of mismeasurement and inaccurate measurement in the prior art.

[0089] In addition, one of the first to fourth sensing signals corresponding to the largest one of the first to fourth perfusion indexes may be selected to calculate the user's heart rate, thereby achieving high-precision heart rate measurement.

[0090] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made using the contents of the present invention's specification and drawings are included in the claims of the present invention.

Claims

1. A head mounted device, characterized in that: The head mounted device comprises: a pair of frames and a beam portion connected between the pair of frames; a pair of nose pads, respectively connected to the pair of frames; Sensing device, including: A first light source and a first light sensor are disposed in a first arrangement in one of the nose pads of the pair of nose pads; and A second light source and a second light sensor are disposed in another nose pad of the pair of nose pads in a second arrangement, wherein the first arrangement is opposite to the second arrangement; and A processing circuit electrically connected to the sensor device, wherein the processing circuit is configured to: Control the first light source and the second light source to emit a first test light and a second test light respectively at different time sequences; receiving a first sensing signal generated by the first light sensor corresponding to the second test light; receiving a second sensing signal generated by the second light sensor corresponding to the first test light; receiving a third sensing signal generated by the first light sensor corresponding to the first test light; receiving a fourth sensing signal generated by the second light sensor corresponding to the second test light; determining whether the head mounted device is in a wearing state according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and In response to determining that the head mounted device is in a wearing state, the user's heart rate is acquired by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

2. The head mounted device according to claim 1, wherein: When the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

3. The head mounted device according to claim 2, wherein: In the step of determining whether the head mounted device is in the wearing state, the processing circuit is further configured to: respectively acquiring a first light intensity, a second light intensity, a third light intensity and a fourth light intensity from the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; Whether the head mounted device is in the wearing state is determined according to at least two of the first light intensity, the second light intensity, the third light intensity, and the fourth light intensity.

4. The head mounted device according to claim 3, wherein: In response to the first light intensity or the second light intensity being greater than a first threshold and the third light intensity or the fourth light intensity being less than a second threshold, the processing circuit is configured to determine that the head mounted device is not in the wearing state.

5. The head mounted device according to claim 3, wherein: In response to the first light intensity increasing by a first value greater than a third threshold and the third light intensity decreasing by a second value greater than a fourth threshold, the processing circuit is configured to determine that the head mounted device is not in the wearing state; or In response to the second light intensity increasing by a third value greater than the third threshold and the fourth light intensity decreasing by a fourth value greater than a fourth threshold, the processing circuit is configured to determine that the head mounted device is not in the wearing state.

6. The head mounted device according to claim 3, wherein: In response to the first light intensity being lower than the third light intensity by a fifth value greater than a fifth threshold, and in response to the second light intensity being lower than the fourth light intensity by a sixth value greater than a sixth threshold, the processing circuit is configured to determine that the head-mounted device is in the wearing state.

7. The head mounted device according to claim 1, wherein: A first direct path between the first light sensor and the first light source is obstructed by a portion of the one of the pair of nose pads, and a second direct path between the second light sensor and the second light source is obstructed by a portion of the other of the pair of nose pads.

8. The head mounted device according to claim 1, wherein: In the step of acquiring the heart rate of the user by processing the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal, the processing circuit is further configured to: obtaining a first perfusion index, a second perfusion index, a third perfusion index and a fourth perfusion index respectively according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; as well as The heart rate of the user is obtained by performing a heart rate calculation procedure on the one of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index.

9. The head mounted device according to claim 8, wherein: Each of the first perfusion index, the second perfusion index, the third perfusion index, and the fourth perfusion index is obtained according to a pulsatile signal and a non-pulsatile signal of each of the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal.

10. The head mounted device according to claim 8, wherein: The heart rate calculation program includes: recording the light intensity of one of the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index as a photoplethysmography signal; and The user's heart rate is calculated and obtained from the photoplethysmographic signal.

11. A sensing method, characterized in that: The sensing method is applicable to a head-mounted device, wherein the head-mounted device comprises a pair of frames, a beam portion connected between the pair of frames, and a pair of nose pads respectively connected to the pair of frames, and the sensing method comprises: Provide sensing devices, including: A first light source and a first light sensor are disposed in a first arrangement in one of the nose pads of the pair of nose pads; and A second light source and a second light sensor are disposed in another nose pad of the pair of nose pads in a second arrangement, wherein the first arrangement is opposite to the second arrangement; and Configure the processing circuit to: Control the first light source and the second light source to emit a first test light and a second test light respectively at different time sequences; receiving a first sensing signal generated by the first light sensor corresponding to the second test light; receiving a second sensing signal generated by the second light sensor corresponding to the first test light; receiving a third sensing signal generated by the first light sensor corresponding to the first test light; receiving a fourth sensing signal generated by the second light sensor corresponding to the second test light; determining whether the head mounted device is in a wearing state according to the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and In response to determining that the head mounted device is in a wearing state, the user's heart rate is acquired by processing the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal.

12. The sensing method according to claim 11, characterized in that: When the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

13. The sensing method according to claim 11, characterized in that: The step of determining whether the head mounted device is in the wearing state further includes: respectively acquiring a first light intensity, a second light intensity, a third light intensity and a fourth light intensity from the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal; and Whether the head mounted device is in the wearing state is determined according to at least two of the first light intensity, the second light intensity, the third light intensity, and the fourth light intensity.

14. The sensing method according to claim 13, characterized in that: In response to the first light intensity or the second light intensity being greater than a first threshold and the third light intensity or the fourth light intensity being less than a second threshold, the processing circuit is configured to determine that the head mounted device is not in the wearing state.

15. The sensing method according to claim 13, characterized in that: When the user wears the head-mounted device on the user's nose, the first sensing signal is generated by the first light sensor receiving the second test light passing through the user's nose, the second sensing signal is generated by the second light sensor receiving the first test light passing through the user's nose, the third sensing signal is generated by the first light sensor receiving the first test light reflected from the user's nose, and the fourth sensing signal is generated by the second light sensor receiving the second test light reflected from the user's nose.

16. The sensing method according to claim 13, characterized in that: The sensing method further includes: in response to the first light intensity being less than the second light intensity and the third light intensity being less than the fourth light intensity, configuring the processing circuit to determine that the head mounted device is not in the wearing state.

17. The sensing method according to claim 11, characterized in that: A first direct path between the first light sensor and the first light source is obstructed by a portion of the one of the pair of nose pads, and a second direct path between the second light sensor and the second light source is obstructed by a portion of the other of the pair of nose pads.

18. The sensing method according to claim 11, characterized in that: The step of obtaining the heart rate of the user by processing the first sensor signal, the second sensor signal, the third sensor signal, and the fourth sensor signal further includes: obtaining a first perfusion index, a second perfusion index, a third perfusion index, and a fourth perfusion index according to the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal, respectively; and The heart rate of the user is obtained by performing a heart rate calculation procedure on the one of the first sensing signal, the second sensing signal, the third sensing signal and the fourth sensing signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index.

19. The sensing method according to claim 18, characterized in that: Each of the first perfusion index, the second perfusion index, the third perfusion index, and the fourth perfusion index is obtained according to a pulsatile signal and a non-pulsatile signal of each of the first sensing signal, the second sensing signal, the third sensing signal, and the fourth sensing signal.

20. The sensing method according to claim 18, characterized in that: The heart rate calculation program includes: recording the light intensity of one of the first sensor signal, the second sensor signal, the third sensor signal and the fourth sensor signal corresponding to the largest one of the first perfusion index, the second perfusion index, the third perfusion index and the fourth perfusion index as a photoplethysmography signal; and The user's heart rate is calculated and obtained from the photoplethysmographic signal.

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