CN219048476U - Heart rate detection module and heart rate detection equipment - Google Patents

Abstract

The application relates to the field of sensors, in particular to a heart rate detection module and heart rate detection equipment. The heart rate detection module comprises a light emitting end and a light receiving end, wherein the light receiving end is used for receiving light signals, emitted by the light emitting end, reflected by skin tissues, and the light signals received by the light receiving end are used for heart rate detection, and the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm. Through setting up the relative position between light-emitting end and the receipts light end for heart rate detection module's interference killing feature improves, can improve the rate of accuracy of heart rate detection when the motion scene.

Description

Heart rate detection module and heart rate detection equipment

Technical Field

The application relates to the field of sensors, in particular to a heart rate detection module and heart rate detection equipment.

Background

For heart rate detection devices for smart bracelets and smart watches, a green light reflective scheme is typically employed. Because the application scene of heart rate detection is mostly sports scene, the heart rate detection can appear light path reliability poor and contact failure and lead to leaking light big scheduling problem under sports scene, and then lead to heart rate measurement inaccurate problem.

Disclosure of Invention

To the inaccurate problem of heart rate measurement that appears among the prior art, this application embodiment provides a heart rate detection module and heart rate check out test set.

A first aspect of embodiments of the present application provides a heart rate detection module, including a light emitting end and a light receiving end; the light receiving end is used for receiving the light signal of the light emitted by the light emitting end after being reflected by skin tissue, and the light signal received by the light receiving end is used for heart rate detection; the light-emitting range of the light-emitting end is conical, and the conical half angle of the conical light-emitting range is greater than or equal to 40 degrees; the light receiving range of the light receiving end is conical, and the conical half angle of the conical light receiving range is smaller than or equal to 33 degrees; the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm.

In one possible implementation manner according to the first aspect, the cone half angle of the cone-shaped light emitting range is greater than or equal to 50 degrees.

In one possible implementation manner according to the first aspect, the cone half angle of the cone-shaped light emitting range is less than or equal to 60 degrees.

In one possible implementation manner according to the first aspect, the cone half angle of the cone-shaped light receiving range is less than or equal to 30 degrees.

In one possible implementation manner, according to the first aspect, a cone half angle of the cone-shaped light receiving range is less than or equal to 25 degrees.

In one possible implementation manner, according to the first aspect, a distance between a center of the light emitting end and a center of the light receiving end is greater than or equal to 2.6mm.

In a possible implementation manner according to the first aspect, a distance between a center of the light emitting end and a center of the light receiving end is 3.8mm.

In one possible implementation manner according to the first aspect, the light receiving end includes a photodiode and a fresnel lens of the light receiving end, and the fresnel lens of the light receiving end is disposed above the photodiode; the distance between the lower surface of the Fresnel lens of the light receiving end and the upper surface of the light sensing area of the photodiode is not less than 0.2mm and not more than 1.0mm; and/or

The light emitting end comprises a light emitting diode and a Fresnel lens of the light emitting end, the Fresnel lens of the light emitting end is arranged above the light emitting diode, and the distance between the lower surface of the Fresnel lens of the light emitting end and the light emitting diode is not less than 0.2mm and not more than 1.0mm.

In one possible implementation manner, along a line direction between the light emitting end and the light receiving end, a ratio of a length of an inner cavity of the window formed by the baffle of the light receiving end to a length of a photosensitive area of the photodiode of the light receiving end is greater than or equal to 1.5.

In one possible implementation manner, according to the first aspect, the light receiving end includes a photodiode, and the light emitting end includes a light emitting diode;

the photodiodes are symmetrically arranged relative to the light emitting diodes; and/or

The light emitting diodes are symmetrically arranged with respect to the photodiodes.

In one possible implementation manner, according to the first aspect, the light receiving end includes a photodiode, and the light emitting end includes a light emitting diode; the light emitting diode is arranged at the center of the light emitting end; the distance between the photosensitive area of the photodiode and the baffle plate at the light receiving end is greater than or equal to 0.1mm.

According to the first aspect, in one possible implementation manner, along a connection line direction of the light emitting end and the light receiving end, a length of an inner cavity of a window formed by a baffle plate of the light receiving end is greater than or equal to 1.5 times a length of a photosensitive area of the photodiode; the center of the photosensitive region of the photodiode is offset from the center of the fresnel lens above the photodiode; the distance from the center of the photosensitive region of the photodiode to the center of the light emitting diode is less than the distance from the center of the fresnel lens above the photodiode to the center of the photosensitive region of the photodiode.

A second aspect of embodiments of the present application provides a heart rate detection module, including a light emitting end and a light receiving end; the light receiving end is used for receiving the light signal of the light emitted by the light emitting end after being reflected by skin tissue, and the light signal received by the light receiving end is used for heart rate detection; the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm; along the connecting line direction of the light emitting end and the light receiving end, the ratio of the length of the inner cavity of the window formed by the baffle plate of the light receiving end to the length of the photosensitive area of the photodiode of the light receiving end is greater than or equal to 1.5.

According to the second aspect, in one possible implementation manner, the light receiving end includes a photodiode and a fresnel lens of the light receiving end, and the fresnel lens of the light receiving end is disposed above the photodiode; the distance between the lower surface of the Fresnel lens of the light receiving end and the upper surface of the light sensing area of the photodiode is not less than 0.2mm and not more than 1.0mm; and/or

The light emitting end comprises a light emitting diode and a Fresnel lens of the light emitting end, the Fresnel lens of the light emitting end is arranged above the light emitting diode, and the distance between the lower surface of the Fresnel lens of the light emitting end and the light emitting diode is not less than 0.2mm and not more than 1.0mm.

According to two aspects, in one possible implementation manner, the light receiving end comprises a photodiode, and the light emitting end comprises a light emitting diode; the light emitting diode is arranged at the center of the light emitting end; the distance between the photosensitive area of the photodiode and the baffle plate at the light receiving end is greater than or equal to 0.1mm.

According to both aspects, in one possible implementation, the center of the photosensitive area of the photodiode is offset from the center of the fresnel lens above the photodiode; the distance from the center of the photosensitive region of the photodiode to the center of the light emitting diode is less than the distance from the center of the fresnel lens above the photodiode to the center of the photosensitive region of the photodiode.

A third aspect of embodiments of the present application provides a heart rate detection device, including a heart rate detection module as in any one of the first or second aspects and a wireless data transmission device, where the wireless data transmission device is configured to transmit heart rate data detected by the heart rate detection module to a user.

Compared with the prior art, the beneficial effects of the embodiment of the application are that: through setting up the relative position between light-emitting end and the receipts light end for heart rate detection module's interference killing feature improves, can improve the rate of accuracy of heart rate detection when the motion scene.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings that are required in the embodiments or the description of the prior art will be briefly described below, it being obvious that the drawings in the following description are only some embodiments of the present application, and that other drawings may be obtained according to these drawings without inventive faculty for a person skilled in the art.

FIG. 1 is a schematic diagram of a heart rate detection system according to an embodiment of the present disclosure;

FIG. 2 is a schematic diagram of an optical path layout of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 3 is a schematic diagram of a relationship between a heart rate signal and a relative distance between two devices according to an embodiment of the present application;

FIG. 4 is a schematic diagram of the current dependence of light reflected in skin tissue over time according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 6 is a schematic diagram of another heart rate detection module according to an embodiment of the present disclosure;

FIG. 7 is a schematic diagram of an optical path layout of another heart rate detection module according to an embodiment of the present disclosure;

FIG. 8 is a schematic diagram illustrating an angle test of an light output end according to an embodiment of the present disclosure;

fig. 9 is a schematic diagram of a change in light intensity collected by a PD according to an embodiment of the present application along with a movement angle of the PD;

fig. 10 is a schematic optical path diagram of an optical output end according to an embodiment of the present disclosure;

FIG. 11 is a schematic diagram illustrating a light receiving angle test of a light receiving end according to an embodiment of the present disclosure;

FIG. 12 is a schematic diagram showing a trend of radiant energy received by a light receiving end along with a movement angle of a collimation light source according to an embodiment of the present disclosure;

fig. 13 is a schematic diagram of an optical path of a receiving end according to an embodiment of the present disclosure;

FIG. 14 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 15 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 16 is a schematic view of a Fresnel lens according to an embodiment of the present disclosure;

FIG. 17 is a diagram of a simulation model of a threaded lens according to an embodiment of the present application;

FIG. 18 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 19 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

FIG. 20 is a schematic diagram of a grating mold according to an embodiment of the present disclosure;

FIG. 21 is a schematic view of a light homogenizing film according to an embodiment of the present disclosure;

FIG. 22 is a schematic diagram of a light receiving end of another heart rate detecting module according to an embodiment of the present disclosure;

FIG. 23 is a schematic diagram of a light receiving end of another heart rate detecting module according to an embodiment of the present disclosure;

FIG. 24 is a schematic diagram showing a relationship between a light receiving angle and a received light signal according to an embodiment of the present disclosure;

FIG. 25 is a schematic diagram of a heart rate detection module according to an embodiment of the present disclosure;

fig. 26 is a schematic diagram of another heart rate detection module according to an embodiment of the present application.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present application more apparent, some embodiments of the present application will be described in detail below by way of example with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in each instance, numerous technical details have been set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the present application can be implemented without these technical details and with various changes and modifications based on the following embodiments.

Referring to fig. 1, the heart rate detection system is composed of a wrist 103 of a tested person and a heart rate detection device 104, where the form of the heart rate detection device includes, but is not limited to, a wristband, a wristwatch, a wrist strap, etc., the heart rate detection device may also be referred to as a heart rate measurement device, and the heart rate detection device 104 includes a heart rate detection sensor (sensor) 107, a microprocessor (CPU) 105, a wireless data transmission device (COMMUNICATION) 108, a display screen or man-machine interaction interface 101, a MEMORY (MEMORY) 106, a watchband device 102, etc. The wireless data transmission device is used for transmitting heart rate data, for example, the wireless data transmission device may be a WIFI device, a bluetooth device, etc., the wireless data transmission device is used for transmitting heart rate data tested by the heart rate detection device to a user, the heart rate detection module includes the heart rate detection sensor, specifically, the heart rate detection sensor may be a Light Emitting semiconductor and a photoelectric semiconductor, the Light Emitting semiconductor may also be referred to as a semiconductor Light emitter, and the Light Emitting semiconductor is illustrated by taking a Light-Emitting Diode (LED) as an example.

For the heart rate detection module, the optical path layout forms may be different from each other, such as the four optical path layout forms (a), (b), (c) and (d) of the heart rate detection module shown in fig. 2, where the light emitting end is denoted by 201 and 203, and the light receiving end is denoted by 202. The light source of the light emitting end 201 may be a green light source, the light source of the light emitting end 203 may be a red light source, and the color of the light source of the light emitting end is not limited in this embodiment, and may be a green light source or a red light source. Although the optical paths are arranged in different modes, the optical paths with the same arrangement mode may be arranged on different equipment, and the problems of poor optical path reliability and poor light leakage inhibition capability and poor heart rate measurement accuracy may occur no matter what type of light source is used.

When analyzing the problem that heart rate detection module exists, find to asymmetric light path, in the in-process of testing heart rate, if wearing state of wearable equipment changes, unilateral inefficacy phenomenon appears easily, easily lead to no signal input to heart rate signal detection reliability is relatively poor. For symmetrical light path, the in-process of testing heart rate, if the wearing state of wearable equipment changes, the device produces the air gap with the wrist easily, and the most light that the light-emitting device launched is easy from skin surface reflection to including photoelectric semiconductor on the receiver, and this invalid light can introduce some interference signal to influence heart rate detection's accuracy greatly. In this embodiment, the Photo semiconductor may be referred to as an optical signal detector, and a Diode (PD) is illustrated as an example.

In addition, for symmetrical or asymmetrical light paths, if the wearing state of the wearable device is changed during the test, an air gap is easily generated between the device and the wrist, and most of ineffective ambient light can be reflected to the light receiving end through the skin surface in a strong light environment, such as outdoor sunlight environment, so that some interference signals are introduced, the pressure of a post-processing circuit and an algorithm is increased, and the accuracy of heart rate detection is also affected.

For heart rate detection modules with symmetrical light path layout, referring to the light path layout in fig. 2 (b), a light emitting end including a single light emitting semiconductor may be placed at the center of the module, and a plurality of light receiving ends may be placed around a single LED. Or referring to the optical path layout form in fig. 2 (c), a single light receiving end is placed in the middle, and multiple light emitting ends are arranged on the left and right sides of the light receiving end, so that the purpose of symmetrically arranging the light emitting end and the light receiving end is to weaken the detection function failure of part of the optical path caused by the change of the wearing state of the wearable device on the wrist.

Based on the disclosure of the foregoing embodiments, the embodiments of the present application provide a heart rate detection module, which may improve the light emitting end of the module to increase the accuracy of heart rate measurement. Specifically, an optical design may be added to the light-emitting end for modifying the light-emitting type. It is understood that the light emitting range of the light emitting end is cone-shaped, and the cone half angle of the cone-shaped light emitting range can be called the half power angle of the light emitting type or the light emitting angle. In this embodiment, according to reasonable spatial distribution, the LED and the structure around the LED may be regarded as an integral light emitting end, where the half power angle of the light emitting end is greater than or equal to 40 °, so that the integral light emitting detection range is relatively large, and more optical signals may be irradiated inside the wrist tissue, so as to improve the accuracy of heart rate detection. In order to achieve a half power angle of 40 degrees or more, the light emitting end may include an optical element such as a fresnel lens, a light homogenizing film, or a convex lens disposed above the light emitting diode, or may be achieved by adjusting a structure of a baffle between the PD and the LED. In this embodiment, the baffle may also be referred to as a retaining wall.

Based on the disclosure of the foregoing embodiments, the embodiments of the present application provide a heart rate detection module, which improves a light receiving end, and may add an optical design to the light receiving end of an optical path, so as to modify a light receiving type of the light receiving end. The light receiving range of the light receiving end is conical, and the conical half angle of the conical light receiving range can be called as the half power angle of the light emitting type or can be directly and simply called as the light emitting angle. In this embodiment, the half power angle of the light receiving light type is set to be less than or equal to 33 degrees, so as to screen and acquire reflected light, increase the probability of receiving the reflected light carrying the heart rate signal, reduce the receiving probability of external ambient light, and reduce the light leakage generated by the light emitting end at the skin. In order to achieve a cone half angle of the cone-shaped light receiving range of less than or equal to 33 degrees, the light receiving end may include an optical element such as a fresnel lens, a privacy film, a grating film, or the like disposed over the photodiode. If the half power angle of the light receiving end is larger than 33 degrees, light leakage of the skin reflecting end and interference of external environment light cannot be effectively restrained, so that the interference quantity of the signal end cannot be effectively restrained, and the accuracy of heart rate detection is affected.

Based on the disclosure of the above embodiment, the embodiment of the application provides a heart rate detection module, if the distance between the light emitting end and the light receiving end is larger, the signal quantity can be greatly attenuated, and the anti-interference capability is poorer, so that the accuracy of heart rate detection is affected. The accuracy of heart rate signal detection can be influenced when the distance between the center of the light receiving end and the center of the light emitting end is greater than 4.2mm, and the interference is mainly reflected. Because the relative distance between the center of the light receiving end and the center of the light emitting end is larger, the propagation path of light in the tissue is larger, and particularly the change of muscle tissue is larger when a human body moves, the optical path in the tissue is changed, so that interference signals are generated, and the signal quality of heart rate detection is influenced. The distance between the center of the light receiving end and the center of the light emitting end is smaller than or equal to 4.2mm in the relative position of the devices of the light path design, and the purpose is to reduce the propagation path of light in tissues so as to reduce the accuracy of interference components in the tissues on heart rate detection. In addition, in this embodiment, the distance between the center of the light-emitting end and the center of the light-receiving end is greater than or equal to 1/2 of the sum of the widths of the light-emitting end and the light-receiving end. The embodiment of the application can improve the accuracy of heart rate detection for the light emitting end, the light receiving end and the setting of the relative positions of the light emitting end and the light receiving end, and can be suitable for most electronic equipment in the light path layout form on the market.

According to the heart rate detection module, the problem that the accuracy of heart rate detection is low in a symmetrical or asymmetrical light path can be solved, in the embodiment, the light emitting angle is greater than or equal to 40 degrees, the light receiving angle is less than or equal to 33 degrees, the distance between the center of the light emitting end and the center of the light receiving end is less than or equal to 4.2mm, the problem that heart rate measurement is inaccurate under the condition that the module is in poor contact with a wrist in a sports scene can be solved, products like a bracelet can still accurately extract heart rate signals under the condition of not closely contacting, and the problem that user experience is influenced due to the fact that the bracelet is required to be too tight is avoided, so that a relatively accurate heart rate recognition effect still exists under a sports state. According to the scheme, the anti-interference capacity of the signals can be improved by orders of magnitude, the resolving precision of heart rate signals can be improved, and the problem that calculation errors caused by wearing position deviation of the heart rate detection module are large is solved. Based on the disclosure of the above embodiment, the embodiment of the present application provides a heart rate detection module, in this embodiment, the half power angle of the light emitting type is greater than or equal to 50 degrees, so that more light signals can be emitted into the wrist tissue, and thus detection covering more heart rate signals is realized. In order to realize that the half power angle of the light range is greater than or equal to 50 degrees, the light emitting end can comprise an optical element such as a Fresnel lens, a light homogenizing film or a convex lens arranged above the light emitting diode, or can be realized by adjusting the structure of a baffle plate between the PD and the LED. In this embodiment, for the light emitting angle, the larger the angle of the light emitting angle, the better, and for each increase of the light emitting angle, the heart rate recognition performance is improved by 0.1%, and specifically, the light emitting angle can be increased to 60 degrees. For ease of description, a fresnel lens may also be referred to simply as a lens.

Based on the disclosure of the foregoing embodiments, the embodiments of the present application provide a heart rate detection module, where in the present embodiment, the half power angle of the light emitting range is less than or equal to 60 °. When the half power angle is equal to 60 degrees, the light emitting end emits light similar to a langer, in this embodiment, the cone half angle of the cone-shaped light emitting range is smaller than or equal to 60 degrees, which is convenient for process implementation, and the light emitting end may include optical elements such as a fresnel lens, a light homogenizing film, or a convex lens disposed above the light emitting diode, or may be implemented by adjusting a structure of a baffle between the PD and the LED.

The influence of the relative position between the light end and the light receiving end on the accuracy of heart rate detection is analyzed in detail below. The distance between the light emitting end and the light receiving end affects the signal quantity of the heart rate to a great extent, and the iac is the magnitude of the current representing the heart rate signal with reference to the following formulas 1 to 4, and is related to Idc and Δl under the condition of light emission of the same wavelength. Where Idc denotes the current generated by the light reflected from the stationary part of the skin tissue, Δl denotes the propagation path of the incident light through the arterial vessel in the tissue. Referring to fig. 3, the horizontal axis in fig. 3 indicates the distance (Distance from LED to PD) between the center of the light emitting end and the center of the light receiving end, which in this embodiment can be understood as the center of the LED and the center of the light receiving end can be understood as the center of the PD. Fig. 3 shows the relation between the heart rate signal amount Iac and the distance, and in fig. 3 iac=idc· (Iac/Idc), iac may characterize the magnitude of the heart rate signal amount. As can be seen from fig. 3, the larger the distance between the centers of the two ends, the weaker the heart rate signal. When the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm, the heart rate signal quantity can be ensured to be stronger, so that the accuracy of heart rate detection is ensured.

In this embodiment, the distance between the light emitting end and the light receiving end may also be set to a lower limit, and in an ideal state, that is, when the distance between the two devices approaches 0 without considering the size of the devices, the theoretical value Iac/Idc is also 0, and the heart rate signal is also 0 at this time. In this embodiment, the lower limit of the distance between the center of the light emitting end and the center of the light receiving end may be set to one half of the sum of the width of the light emitting end and the width of the light receiving end.

Referring to fig. 3, the greater the distance between the center of the light-emitting end and the center of the light-receiving end, the exponentially decaying Idc, and the linearly increasing Iac/Idc, when the distance between the center of the light-emitting end and the center of the light-receiving end is a certain specific distance, the Iac will start to generate a sharp-falling inflection point at this point, and the sharp-falling inflection point of the Iac is set as C1, in this embodiment, C1 is 4.2mm. Therefore, when the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm, the heart rate signal quantity can be ensured to meet the heart rate measurement requirement. In the following formula, I ₀ The current caused by the incident light to the skin tissue is represented, and the energy of the incident light to the skin tissue can be calculated from the current. Epsilon ₀ Representing the absorbance of a constant portion (including veins, muscles, bones, etc.) within the skin tissue, C ₀ Is one half of the distance between the center of the LED and the center of the PD, L ₁ Representing the path of incident light through the artery in the tissue _HbO2 Represents the absorbance coefficient, C, of HbO2, which is an oxyhemoglobin in blood, to a specific wavelength _HbO2 Represents the concentration of oxyhemoglobin in blood (Concentration of HbO, C _HbO2 ) L represents the propagation path of incident light through stationary parts (including veins, muscles, bones, etc.) in the tissue, ε _Hb Representing the absorbance coefficient of reduced hemoglobin Hb in blood at a specific wavelength, C _Hb Indicating the concentration of reduced hemoglobin in blood (Concentration of Hb, C _Hb ), I _OUT Indicating the current caused by the light reflected from the skin tissue. Iac represents electricity caused by light reflected from skin tissue and carrying arterial pulsating componentThe flow, iac, may characterize the heart rate signal. The pulse portion is the current caused by the light carrying the arterial wave component reflected from the skin tissue, and the signal quantity of the heart rate can be characterized, and the minimum value is Imin and the maximum value is Imax. By stationary portion, it is understood the current caused by the reflection of the incident light within the skin tissue after passing the stationary portion.

Specifically, the LED at the light emitting end may be a green LED, the LED may be turned on at a certain interval, the light receiving end may collect data to a micro control unit (Microcontroller Unit, MCU) through a conditioning circuit and an Analog-to-Digital Converter (ADC), and calculate an ac component of a green light intensity signal to implement calculation of a heart rate. Specifically, the conditioning circuit of the light receiving end may include an ac coupling circuit, and the conditioning circuit may be implemented by a transimpedance amplifier with adjustable gain. When the heart beats, which causes the arterial vessel to beat, the light is modulated by the arterial beat, and the heart rate signal can be calculated by processing the changes in the photoelectric signal. In addition, the calculated heart rate signals can be transmitted to the mobile phone of the user through Bluetooth, wifi or other wireless data transmission modules.

Referring to the schematic diagram of heart rate detection shown in fig. 5, the heart rate detection module shown in fig. 5 includes a printed circuit board (Printed Circuit Board, PCB) PCB501, a light emitting end, and a light receiving end. The light emitting end and the light receiving end are arranged on the surface of the PCB. In fig. 5, the light-emitting end includes an LED502, and the light path 54 represents light leakage reflected by the skin surface of the light signal emitted by the LED when the LED is driven, where the light leakage path 54 is caused by a gap between the skin and the detection device. The optical path 55 represents light leakage reflected by the external solar radiation on the skin surface, and 506 represents WRIST TISSUE (WRIST tissu).

Referring to the schematic diagram of the heart rate detection module shown in fig. 6, 604 indicates a wrist tissue, 606 indicates a substrate, and the upper surface of the substrate is provided with a light emitting end and a light receiving end, in this embodiment, the light emitting end and the light receiving end share a baffle 607, and the baffle 607 is used for shielding the transmission of the transverse light between the LED608 and the PD605, so as to prevent the weak transverse light emitted by the LED from being crossly transmitted to the PD. In this embodiment, the baffle may also be referred to as a rib. The module may further include a sub-dak cover 609 disposed over the LED and PD, the sub-dak cover being configured to protect the light emitting semiconductor and PD.

Based on the disclosure of the foregoing embodiment, in this embodiment, the distance between the center of the light emitting end and the center of the light receiving end is greater than or equal to 2.6mm. The light emitting end and the light receiving end may be respectively configured with a baffle, or may share one baffle, and if one baffle is shared, the distance between the center of the light emitting end and the center of the light receiving end is smaller. Referring to fig. 6, the thickness S1 of the baffle is at least 0.8mm, for example 1.1mm, and the minimum distance between the center of the light emitting end and the center of the light receiving end is 2.6mm due to the inherent thickness of the light emitting end and the light receiving end. For example, in fig. 6, the thickness S2 of the LED is 0.8mm, the width S4 of the gap between the LED and the barrier is 0.1mm, the barrier thickness S1 is 1.1mm, the gap S5 between the PD and the barrier is 0.1mm, and the thickness S3 of the PD is 1.8mm. In addition, the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm.

The light leakage caused by the LED has four steps, firstly the LED emits light, and if the detection device has a gap with the skin, part of light returns to the PD end through the gap when the LED emits light, so that ineffective light leakage is received when the PD works. In the above 4 steps, the light emitting of the LED and the light receiving of the PD are the necessary conditions for detecting the heart rate signal, the gap between the detecting device and the skin is a highly probable event occurring during the actual movement, and the ineffective light leakage can be reduced by improving the light path structure through the gap and returning to the PD end.

Referring to fig. 6, the heart rate detection module includes a light emitting end, a light receiving end, a substrate of an electronic component, and a schlieren cover 809. The substrate is for example a PCB or a flexible circuit board (Flexible Printed Circuit, FPC). The baffle 607 in fig. 6 is common to the light-emitting end and the light-receiving end, i.e., it can be understood that the light-emitting end includes the LED608 and a portion of the baffle 607, and the light-receiving end includes the PD605 and a portion of the baffle 607. In this embodiment, 601 represents the light emitting path of the light emitting semiconductor, S6 represents the distance between the heart rate detection module and the wrist skin tissue 604, 603 represents the light receiving path of the PD605, and the width of the baffle 607 is S1, so θ1=artan (2×s6/S1), and if the widths of the LED608 and the PD605 are regarded as 0, S1 can be regarded as the distance between the LED and the PD. When θ1=θ2, it can be understood that the optical signal received by the PD is mostly due to reflection on the skin surface, and thus, the accuracy of heart rate detection is low, and the optical paths 601 and 603 shown in fig. 6 can be regarded as the case where the optical signal is reflected on the skin surface. When θ2 is less than or equal to θ1, the received light leakage is more, and the heart rate performance is poor. In this embodiment, θ2 is larger than θ1, so that the light receiving angle is smaller, and a part of reflected light from the skin surface can be removed, thereby improving the heart rate detection performance. In this embodiment, θ2 may be 65 degrees.

In this embodiment, the light emitting range of the light emitting end is cone-shaped, the cone half angle of the cone-shaped light emitting range may be referred to as the light emitting angle, please refer to fig. 6, the light emitting angle is (90- θ1), the light receiving range of the light receiving end is cone-shaped, the cone half angle of the cone-shaped light receiving range may be referred to as the light receiving angle, the smaller the light emitting angle and the light receiving angle are, the larger the smaller the θ1 and the θ2 are, the larger the light emitting angle and the light receiving angle are, although the increase of the light emitting angle and the light receiving angle is helpful for detecting the heart rate signal, but the light leakage is also more serious. On the contrary, the smaller the light emitting angle and the light receiving angle are, the smaller the light leakage is, the smaller the introduced disturbance quantity is in the exercise heart rate detection process, the high-quality heart rate signals can be obtained, and the balance of the light emitting angle and the light receiving angle is of great importance. When the light receiving angle is smaller than the light emitting angle, the light receiving end plays a role in isolating light reflected by the skin surface. In order to ensure that the heart rate signal quantity is as large as possible, the anti-motion interference capability of the system can be ensured to be strong, the angle limitation can be carried out at the light receiving end, the optical signals of the light leakage part are filtered by blocking, and the optical signals carrying the heart rate signal from skin tissues are screened so as to ensure the optimal detection of the system on the heart rate signal.

In this embodiment, the light source, living tissue and optical signal detector at the light emitting end all affect heart rate detection, and in the early stage of heart rate detection, the more optical signals are irradiated into skin tissue, the larger the range of the detected skin tissue is, the more the carried arterial heart rate component signals are, which is more beneficial to heart rate calculation, namely, the larger the light emitting angle (90-theta 1) is, the more beneficial to heart rate detection. For the light receiving angle, the light receiving angle (90-theta 2) can screen the reflected light of the two parts of the light leakage path inside the tissue, and ideally, the light receiving angle is 0 degrees, namely, only the light signals under collimation are received, because the light signals of the parts are basically all light signals from heart rate signals carried inside skin tissues, and the acquisition of high-quality heart rate signals is facilitated.

The optical path layout adopted in the embodiment of the present application may refer to fig. 7, and the optical path layout may adopt a symmetrical form. Referring to fig. 7 (b), the heart rate detection module may employ 1 LED701 and a plurality of PDs 702 disposed around the LEDs. Alternatively, referring to fig. 7 (a), the heart rate detection module may employ a plurality of LEDs and 1 PD, and the plurality of LEDs are disposed around the PD. Alternatively, referring to fig. 7 (c), the heart rate detection module may be configured by a plurality of LEDs and a plurality of PDs, which are symmetrical. In the heart rate detection module provided in this embodiment, one or more LEDs and PDs may be provided. The green light emitted by the light emitting end enters the skin in a large range, so that more optical signals are diffused in tissues, and signal detection with more heart rate components can be covered. If the half power angle of the light emitting part is larger than or equal to 40 degrees, the diffused light entering the tissue can be relatively increased, the detection of heart rate signals can be covered in a large range, the heart rate signal quantity can be enhanced, and the heart rate detection accuracy is improved.

Based on the foregoing, in this embodiment, the accuracy of heart rate detection may be improved by improving the half-power angle. It can be understood that the angle of the light-emitting type of the light-emitting end should be matched with the angle design of the light-receiving type of the light-receiving end, because the range of the light-emitting type is relatively wide, for convenience of understanding, the physical quantity of the half-power angle is defined, the angle with the strongest center angle of the light signal as the reference, and in the whole light type diagram, the half-power angle is defined as the angle with the half of the strongest light signal as the boundary. Referring to the light-emitting angle test method of the light-emitting end shown in fig. 8, the PD for detection moves around the light-emitting end to be detected to detect the light emitted by the light-emitting end, the light movement track of the PD for detection is a semicircle, and the movement angle of the PD for detection is from-90 degrees to 90 degrees. When the PD for detection moves around the optical end to be detected, the PD for detection receives the optical signal, and the PD for detection can acquire a schematic diagram of the change of the light intensity along with the movement angle of the PD for detection shown in fig. 9, where the horizontal axis represents the movement angle of the PD for detection, and the vertical axis represents the normalized light intensity received by the PD for detection. The figure shows the magnitude of the optical signal it receives when detecting the PD moving from-90 degrees around a circular optical motion trajectory to 90 degrees. When the angle is 0 degrees, namely when the detection PD is right above the light emitting end to be detected, the optical signal measured by the detection PD is strongest, and when the angle is-90 degrees and 90 degrees, namely when the detection PD is left and right of the light emitting end to be detected, the optical signal measured by the detection PD is weakest, so that the half-power angle of the light emitting end can be determined by taking half of the strongest optical signal as a boundary.

Based on the foregoing embodiments, in this embodiment, a fresnel lens may be added above the LED at the light-emitting end to change the light-emitting type of the light-emitting portion, so as to achieve light-emitting at a large angle, or a light-homogenizing film may be added to achieve change of the light-emitting portion, so that the light-emitting angle is increased. Alternatively, a fresnel lens and a light homogenizing film may be used simultaneously. Taking the fresnel lens as an example, please refer to the schematic diagram of the light emitting end shown in fig. 10, 1001 represents an LED, for example, a green light emitting LED, and 1002 represents a baffle plate of the light emitting end, which can form a light window above the LED. Reference numeral 1003 denotes a fresnel lens, 1004 denotes an exit light type of an exit end when the fresnel lens 1003 is not added, 1005 denotes an exit light type of an exit end after adding the fresnel lens, 1006 denotes a normal line to assist observation, a1 denotes an exit angle of an exit end without adding the fresnel lens, and a2 denotes an exit angle of an exit end with adding the fresnel lens. As is clear from fig. 10, the light extraction angle increases from a1 to a2 after adding the fresnel lens, and the light extraction pattern increases from 1004 to 1005 after adding the fresnel lens.

In this embodiment, through reasonable optical design, the light receiver may be configured with reasonable spatial distribution, and the PD and the baffles around the PD are regarded as an integral light receiver, where the half-power angle of the light receiver is less than or equal to 30 degrees, for example, the half-power angle of the light receiving portion is 25 °. The PD and the LED are blocked by the black retaining wall, so that the interference of light leakage on the signal quantity can be reduced. In this embodiment, the performance is improved by about 0.1% for every 1 degree decrease in the acceptance angle. As shown in fig. 5, the heart rate detection module is often worn on the wrist in a loose state during practical application, so that a certain air gap is generated between the device and the wrist. The gap of the part can introduce light leakage of two parts, one of the light leakage is reflected light on the skin surface when the light emitting end emits light, and the reflected light does not carry heart rate signals and belongs to ineffective light. And the other is the reflected light of the external environment light on the skin surface, and the reflected light does not carry a heart rate signal, and belongs to ineffective light. The half power angle of the light receiving part can be smaller than or equal to 25 degrees by adjusting the light receiving angle of the light receiving end, so that light leakage in a loose wearing state is effectively inhibited, the interference quantity of heart rate signals is reduced, and the heart rate detection accuracy is improved.

Referring to the method for testing the light receiving angle of the light receiving end shown in fig. 11, the collimating light source is used as the light emitting end to move around the light receiving end to be tested, the light movement track of the collimating light source is a semicircle, and the movement angle of the collimating light source is from-90 degrees to 90 degrees. When the collimation light source moves around the light end to be measured, the light receiving end to be measured receives the light signal to test the light receiving angle of the light receiving end to be measured, for example, the light receiving end to be measured can obtain a test result diagram of the light receiving angle shown in fig. 12, wherein the horizontal axis represents the movement angle of the collimation light source, and the vertical axis represents the normalized radiation energy received by the light receiving end. The diagram shows the size of the optical signal received by the light receiving end to be measured when the collimation light source moves from-90 degrees around the circular optical movement track to 90 degrees, the optical signal measured by the light receiving end to be measured is strongest when the collimation light source is positioned right above the light receiving end to be measured at 0 degrees, the optical signal measured by the light receiving end to be measured is weakest when the collimation light source is positioned at-90 degrees and 90 degrees, namely, the collimation light source is positioned at the left side and the right side of the light receiving end to be measured, and therefore the half-power angle of the light receiving end can be determined by taking the strongest optical signal of one half as a boundary.

In this embodiment, fig. 9 and fig. 12 may be understood as graphs of the amplitude of the optical signal with respect to the angle, the amplitude of the optical signal may be the amplitude after normalization, or fig. 9 and fig. 12 may be understood as graphs of the energy of the optical signal with respect to the angle, the energy of the optical signal is the normalized energy. After normalization, the value of the y-axis corresponding to the maximum amplitude or energy is 1, the value of the y-axis is 0.5 to determine the half-power angle, and when the value of the y-axis is 0.5, the value of the x-axis corresponding to the 0.5 of the y-axis can be used for determining the half-power angle.

In order to adjust the light receiving angle, one or more of a Fresnel lens, a peep-proof film, a concave lens and a grating film can be arranged above the PD. Taking fresnel lens addition as an example, please refer to the optical path diagram of the light receiving end shown in fig. 13, 1301 denotes PD,1302 denotes a baffle around PD, 1303 denotes fresnel lens, 1304 denotes a light pattern diagram of the light receiving end with fresnel lens 1303 added, 1305 denotes a light pattern diagram of the light receiving end without fresnel lens added, for convenience of observation, normal line 1306 is shown, b2 is the light receiving angle of the light receiving end with fresnel lens added, and b1 is the light receiving angle of the light receiving end without fresnel lens added. For the light receiving end, after the fresnel lens is added, the light receiving angle is reduced from b1 to b2, and the light receiving type is reduced from 1305 to 1304, in this embodiment, light leakage reflected by the skin and interference of external ambient light can be effectively inhibited by reducing the light receiving angle, so that the interference amount can be effectively inhibited, and thus the accuracy of heart rate detection is ensured.

The foregoing embodiments provide three improvements, namely, an improvement in the optical path of the light-emitting end, an improvement in the optical path of the light-receiving end, and an improvement in the relative position of the device. Specifically, the light-emitting angle of the light-emitting end is greater than or equal to 40 degrees, the light-receiving angle of the light-receiving end is less than or equal to 33 degrees, and the distance between the center of the light-emitting end and the center of the light-receiving end is less than or equal to 4.2mm. Since these three conditions interact with each other, failure of any one condition may result in inaccurate heart rate measurements. When the heart rate detection module meets the three conditions, the heart rate measurement performance is optimal.

Based on the disclosure of the foregoing embodiment, in this embodiment, a symmetrical optical path may be used to increase the interference resistance of the optical path. As shown in fig. 14, during the actual movement, the relationship between the detection device and the skin tissue often appears in the form of fig. 14, and a part of the optical path generates a failure phenomenon, such as a left suspended part, at this time, the light leakage amount (interference signal) occupies the dominant part of the signal, and the heart rate signal is likely to be submerged in the interference signal, so that the heart rate signal cannot be detected. If the light path is designed into a symmetrical structure, the right light path still keeps an effective working area, the light leakage quantity of the light path is smaller than that of the left light path, and the heart rate signal is not submerged in the interference quantity, so that the light path of the right part can still realize the detection of the heart rate signal under the extreme condition, and the stability of the whole light path system to the heart rate detection is ensured. The heart rate detection module shown in fig. 14 includes a PCB 1401, an LED 1402, and two PDs 1403. In fig. 14 1404, the light leakage path of the LED on the skin surface is shown, 1405, the Wrist Tissue (write Tissue) is shown, and 1406, the reflected light carrying the heart rate signal is shown.

Based on the disclosure of the above embodiment, in this embodiment, a symmetrical light path is taken as an example, and referring to fig. 15, the heart rate detection module shown in fig. 15 includes a PCB1501, an LED 1502, a PD 1503, and a baffle 1504 between the PD and the LED. In fig. 15, 1505 represents light reflected within tissue by the LED, 1506 represents wrist skin tissue, 1507 represents arterial blood vessels, 1508 represents wrist bone. The light-emitting angle of the light-emitting end is increased, namely the light-emitting range of the light-emitting end is increased, so that the detection of more arterial blood vessels 1507 can be effectively covered. The light receiving range of the light receiving end is reduced, light signals transmitted in the shallow layer can be removed, and the heart rate signal quantity carried by the light signals transmitted in the shallow layer is reduced. The heart rate signal carried by the shallow propagating optical signal is primarily a direct current null. After the shallow layer propagated optical signals are removed, the deeper optical signals are convenient to extract, and the deeper optical signals carry a large heart rate signal quantity.

Based on the disclosure of the foregoing embodiment, in this embodiment, the fresnel lens design may be added to the light-emitting end, and a specific thread design may be adopted to increase the light-emitting angle of the light-emitting end. The light receiving end can be additionally provided with a Fresnel lens with specific threads, and the Fresnel lens is used for reducing the light receiving angle of the light receiving end. Reference to a fresnel lens may refer to fig. 16, a threaded lens may be used as the fresnel lens, a simulation model diagram of the threaded lens may refer to fig. 17, and as shown in fig. 17, the threaded lens is disposed above the LED and may be used to increase the light exit angle of the light exit end.

Based on the disclosure of the foregoing embodiment, in this embodiment, the light emitting end and the light receiving end may both adopt the fresnel lens design, please refer to the schematic diagram of the heart rate detection module shown in fig. 18, and the heart rate detection module shown in fig. 18 includes the fresnel lens 1801 above the PD, the PD 1802, the fresnel lens 1803 above the semiconductor light emitter, and the semiconductor light emitter 1804, where the center of the PD and the center of the lens coincide.

In fig. 18 and 19, the PD is symmetrically disposed with respect to the semiconductor light emitter. For another example, in fig. 7 (a), the LED701 is symmetrically disposed with respect to the PD702, and in fig. 7 (c), the LED is symmetrically disposed with respect to the PD, and the PD is symmetrically disposed with respect to the LED.

Based on the disclosure of the foregoing embodiment, in this embodiment, the light receiving end may use a peep-proof film, the light emitting end may use a light homogenizing film, please refer to the schematic diagram of the heart rate detection module shown in fig. 19, and the heart rate detection module shown in fig. 19 includes the peep-proof film 1901 above the PD, the PD1902, the light homogenizing film 1903 above the LED, and the LED 1904.

Based on the disclosure of the foregoing embodiment, in this embodiment, a fresnel lens, a peep-proof film, a grating film or a prism column film may be disposed above a PD at the light receiving end, so as to reduce the light receiving type design of the light receiving end, for example, the grating film as shown in fig. 20 may be covered above the PD.

Based on the disclosure of the above embodiment, in this embodiment, a light-homogenizing film may be added to the light-emitting end, and the light-homogenizing film is used to increase the light-emitting type of the light-emitting end, for example, a light-homogenizing film as shown in fig. 21 may be disposed above the LED.

Based on the disclosure of the above embodiment, in this embodiment, as shown in the schematic view of the light receiving end in fig. 22, if LEDs are disposed above and below the PD2201, the ratio r=d1/D2 of the length D1 of the inner cavity of the window 2202 formed by the baffle plate of the light receiving end in the connection line direction of the PD and the LED to the length D2 of the photosensitive area (Radiant Sensitive area) of the PD in the connection line direction is set to be greater than or equal to 1.5. If the ratio R is set to 1, an aesthetic effect can be achieved, and the modules appear to the user as light sensitive areas, i.e. all gray. In this embodiment, the photosensitive region may also be referred to as an AA region. When R is set to be greater than 1.5, the light receiving angle of the light receiving end is set to be not greater than 30 degrees, so that the accuracy of heart rate measurement can be further improved, and the light receiving angle of the light receiving end can be set to be 25 degrees. The light receiving efficiency of the PD is related to the R value, and when the R value is small, if the light receiving range of the light receiving angle is small, the light receiving efficiency is lowered. Taking the example of a circle with the size of the AA area of the PD being 2.8mm by 1.4mm and the size of the lens being 4.2mm in diameter as an illustration, if the window is rectangular, the window is a structure formed by baffles and surrounding the PD or the LEDs, and the window structure is suitable for most Fresnel lenses, and the window can be also called as an optical window. The optical window in this embodiment is described by taking an optical window formed by a baffle plate at the light receiving end as an example, and assuming that the length D1 of the inner cavity of the lens optical window on the left side in fig. 22 is 4mm and the length D2 of the photosensitive region of pd is 1.4mm, the ratio R is 4mm/1.4 mm=2.86, and R is greater than 1.5. It is understood that LEDs may be disposed around the PD, respectively, so that in the connection direction between the other PD and the LEDs, the ratio r=d3/D4 of the length D3 of the window of the light receiving end to the length D4 of the photosensitive area of the PD in the connection direction is set to be greater than or equal to 1.5. In this embodiment, the lens is disposed above the PD to cover the AA area, so as to solve the problem of overall light path aesthetics.

Referring to the schematic diagram of the light receiving end shown in fig. 23, if LEDs are disposed above and below the PD2301, the length D5 of the inner cavity of the optical window 2302 formed by the baffle is 4.2mm and the length D6 of the light sensing area of the PD2301 is 1.4mm in the connection line direction between the PD and the LEDs, the ratio R is 4.2mm/1.4 mm=3, and R is greater than 1.5.

When R >1.5, reference may be made to the graph of the relationship between the light receiving angle and the received optical signal shown in fig. 24, where the horizontal axis represents the light receiving angle, and the vertical axis represents the intensity of the received optical signal, and when the light receiving angle of the light receiving end is 25 °, each angle in the range may ensure that the intensity of the received optical signal is stronger, so that the light intensity may reach 0.15W/Sr, so as to ensure better heart rate measurement accuracy.

Based on the disclosure of the above embodiment, in this embodiment, the distance between the lower surface of the lens and the upper surface of the AA area of the PD may be D7,0.2mm is equal to or less than D7 is equal to or less than 1.0mm, where 0.2mm is a safe distance, so that the lens is not ensured to contact the photosensitive area of the PD, and the effect of the lens is prevented from being limited due to the fact that D7 is set too small, so that the light receiving angle is not easy to reach 25 degrees. In addition, the Fresnel lens can be arranged above the LED, the distance between the lower surface of the Fresnel lens at the light emitting end and the light emitting diode is not smaller than 0.2mm and not larger than 1.0mm, the lens can be prevented from being in contact with the LED, and the lens is prevented from being limited due to the fact that the distance is too small, so that the light emitting angle is too small.

Based on the disclosure of the foregoing embodiment, in this embodiment, as shown in the schematic diagram of the heart rate detection module shown in fig. 25, the diameter of the fresnel lens may be set to 4.2mm, the width of the retaining wall may be set to 1mm, and the distance between the center of the light emitting end and the center of the light receiving end may be set to 4.2mm. In this embodiment, the module includes 4 PDs, namely PD0, PD1, PD2, and PD3. The 4 PDs are arranged around the LED arranged in the center of the module, and the center of the 4 PDs may or may not coincide with the center of the lens above the 4 PDs. In fig. 25, the center of the PD is offset from the center of the lens above it by a predetermined distance, and the smaller the center distance between the PD and the LED, the better the performance, and therefore, the PD can be offset from the lens center above it to improve the performance. In addition, the smaller the light receiving angle, the better the performance, the larger the light emitting angle, and the better the performance. When the lens size is relatively large, but the PD in the optical window is relatively small, the PD can have relatively much movement space, and after the light emitting angle and the light receiving angle reach the conditions specified in the foregoing embodiments by design, the center of the PD can be deviated from the center of the lens above the PD by utilizing the flexible space inside the optical window, so as to further reduce the center distance of the device to achieve the performance optimization.

Referring to fig. 22, if LEDs are disposed above and below the PD, in the direction of the connection between the PD and the LEDs, the length of the PD in the direction of the connection is D2, and the PD is disposed in the optical window, so as to ensure that the PD can receive enough optical signals, a distance D8 between the photosensitive area of the PD and the baffle at the light receiving end is greater than or equal to 0.1mm. The distance from the upper edge of the photosensitive area of the PD to the optical window is greater than or equal to 0.1mm. In addition, the distance from the lower edge of the photosensitive region of the PD to the optical window is greater than or equal to 0.1mm. In this example, D1.gtoreq.D2+0.2 mm can be understood. If a lens is arranged above the PD, D1 is more than 1.5 x D2, namely, in the direction of connecting the PD and the LED, the length of a photosensitive area of the PD, which is formed by a baffle plate of a light receiving end and is used for forming a window, is more than 1.5 times that of the photosensitive area of the PD, so that the lens can play a role in reducing the light receiving angle, when D1 is far more than D2, the PD has a space for moving in the light window, and the PD can deviate from the center of the lens, so that the distance between the LED and the PD is reduced, and the heart rate measurement accuracy is improved. Specifically, the PD is offset toward the direction of the LED when offset from the lens, and the center of the PD is farther from the center of the LED than the center of the lens at the light receiving end.

Based on the disclosure of the foregoing embodiment, in this embodiment, as shown in a schematic diagram of a heart rate detection module shown in fig. 26, the module includes 4 PDs, which are respectively PD0, PD1, PD2, and PD3. The 4 PDs are arranged around the LED, the PD can select a device with a size of 2.8mm x 1.4mm in a photosensitive area, and the size of an opening window of the PD can be 2.8mm x 1.4mm so as not to shade the effective photosensitive area as much as possible. The thickness of the baffle plate in the middle of the LED and the PD can be 1.0mm, the distance between the center of the light emitting end and the center of the light receiving end is 3.8mm, the distance between the center of the LED and the center of the PD can be 3.8mm, and the distance between the upper surface of the photosensitive area of the PD and the upper surface of the baffle plate can be 1.1mm.

In this embodiment, the heights of the light emitting end and the light receiving end may be the same, for example, both are 0.6mm. A fresnel lens may be provided above the PD, and the distance from the lens to the PD may be 0.5mm. A fresnel lens may be provided over the LED, and the distance from the fresnel lens to the LED may be 0.5mm.

The embodiment of the present application provides a heart rate measurement device, which includes a heart rate detection module and a wireless data transmission device provided in the foregoing embodiment, where the wireless data transmission device is configured to transmit heart rate data measured by the heart rate measurement module to a user, for example, reference may be made to 104 shown in fig. 1, and the foregoing embodiment is specifically implemented, which is not repeated herein.

It should be understood that in the embodiments of the present application, "B corresponding to a" means that B is associated with a, from which B may be determined. It should also be understood that determining B from a does not mean determining B from a alone, but may also determine B from a and/or other information.

In addition, the term "and/or" herein is merely an association relationship describing an association object, and means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, and are not repeated herein.

In the several embodiments provided in this application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.

The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit.

The foregoing is merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any person skilled in the art can easily think about changes or substitutions within the technical scope of the present application, and the changes and substitutions are intended to be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims (17)

1. The heart rate detection module is characterized by comprising a light emitting end and a light receiving end;

the light receiving end is used for receiving the light signal of the light emitted by the light emitting end after being reflected by skin tissue, and the light signal received by the light receiving end is used for heart rate detection;

The light-emitting range of the light-emitting end is conical, and the conical half angle of the conical light-emitting range is greater than or equal to 40 degrees;

the light receiving range of the light receiving end is conical, and the conical half angle of the conical light receiving range is smaller than or equal to 33 degrees;

the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm.

2. The heart rate detection module of claim 1, wherein a cone half angle of the cone-shaped light emitting range is greater than or equal to 50 degrees.

3. The heart rate detection module of claim 1, wherein a cone half angle of the cone-shaped light emitting range is less than or equal to 60 degrees.

4. A heart rate detection module according to any one of claims 1 to 3 wherein the cone half angle of the cone shaped light receiving range is less than or equal to 30 degrees.

5. A heart rate detection module according to any one of claims 1 to 3 wherein the cone half angle of the cone shaped light receiving range is less than or equal to 25 degrees.

6. A heart rate detection module according to any one of claims 1 to 3, wherein the distance between the centre of the light emitting end and the centre of the light receiving end is greater than or equal to 2.6mm.

7. A heart rate detection module according to any one of claims 1 to 3, wherein the distance between the centre of the light emitting end and the centre of the light receiving end is 3.8mm.

8. A heart rate detection module according to any one of claims 1 to 3, wherein the light receiving end comprises a photodiode and a fresnel lens of the light receiving end disposed above the photodiode; the distance between the lower surface of the Fresnel lens of the light receiving end and the upper surface of the light sensing area of the photodiode is not less than 0.2mm and not more than 1.0mm; and/or

The light emitting end comprises a light emitting diode and a Fresnel lens of the light emitting end, the Fresnel lens of the light emitting end is arranged above the light emitting diode, and the distance between the lower surface of the Fresnel lens of the light emitting end and the light emitting diode is not less than 0.2mm and not more than 1.0mm.

9. A heart rate detection module according to any one of claims 1 to 3, wherein a ratio of a length of a windowed inner cavity formed by a baffle of the light receiving end to a length of a photosensitive region of a photodiode of the light receiving end is greater than or equal to 1.5 along a line direction of the light emitting end and the light receiving end.

10. A heart rate detection module according to any one of claims 1 to 3, wherein the light receiving end comprises a photodiode and the light emitting end comprises a light emitting diode;

the photodiodes are symmetrically arranged relative to the light emitting diodes; and/or

The light emitting diodes are symmetrically arranged with respect to the photodiodes.

11. A heart rate detection module according to any one of claims 1 to 3, wherein the light receiving end comprises a photodiode and the light emitting end comprises a light emitting diode;

the light emitting diode is arranged at the center of the light emitting end;

the distance from the photosensitive area of the photodiode to the baffle plate of the light receiving end is greater than or equal to 0.1mm.

12. The heart rate detection module according to claim 11, wherein a length of a windowed inner cavity formed by a baffle of the light receiving end is greater than or equal to 1.5 times a length of a photosensitive area of the photodiode along a connection line direction of the light emitting end and the light receiving end;

the center of the photosensitive area of the photodiode is deviated from the center of the Fresnel lens above the photodiode;

the distance from the center of the photosensitive region of the photodiode to the center of the light emitting diode is smaller than the distance from the center of the fresnel lens above the photodiode to the center of the photosensitive region of the photodiode.

13. The heart rate detection module is characterized by comprising a light emitting end and a light receiving end;

the light receiving end is used for receiving the light signal of the light emitted by the light emitting end after being reflected by skin tissue, and the light signal received by the light receiving end is used for heart rate detection;

the distance between the center of the light emitting end and the center of the light receiving end is smaller than or equal to 4.2mm;

along the connecting line direction of the light emitting end and the light receiving end, the ratio of the length of the inner cavity of the window formed by the baffle plate of the light receiving end to the length of the photosensitive area of the photodiode of the light receiving end is greater than or equal to 1.5.

14. The heart rate detection module of claim 13, wherein the light receiving end comprises the photodiode and a fresnel lens of the light receiving end, the fresnel lens of the light receiving end being disposed above the photodiode; the distance between the lower surface of the Fresnel lens of the light receiving end and the upper surface of the light sensing area of the photodiode is not less than 0.2mm and not more than 1.0mm; and/or

The light emitting end comprises a light emitting diode and a Fresnel lens of the light emitting end, the Fresnel lens of the light emitting end is arranged above the light emitting diode, and the distance between the lower surface of the Fresnel lens of the light emitting end and the light emitting diode is not less than 0.2mm and not more than 1.0mm.

15. The heart rate detection module of claim 13, wherein the light receiving end comprises a photodiode and the light emitting end comprises a light emitting diode;

the light emitting diode is arranged at the center of the light emitting end;

the distance from the photosensitive area of the photodiode to the baffle plate of the light receiving end is greater than or equal to 0.1mm.

16. The heart rate detection module of claim 14 or 15, wherein,

the center of the photosensitive area of the photodiode is deviated from the center of the Fresnel lens above the photodiode;

the distance from the center of the photosensitive region of the photodiode to the center of the light emitting diode is smaller than the distance from the center of the fresnel lens above the photodiode to the center of the photosensitive region of the photodiode.

17. Heart rate detection apparatus comprising a heart rate detection module as claimed in any one of claims 1 to 16 and wireless data transmission means for transmitting heart rate data detected by the heart rate detection module to a user.

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