TWI743491B - Flexible physiological sensing device - Google Patents

Abstract

A flexible physiological sensing device includes a flexible substrate, a first light-emitting element, and a first photodetector. The first light-emitting element is disposed on the flexible substrate, and is configured to emit an infrared light to irradiate skin tissues. The infrared light is reflected by the skin tissues to generate a reflective light. The first light-emitting element includes quantum dot materials. The first photodetector is disposed on the flexible substrate, and is adjacent to the first light-emitting element. The first photodetector is configured to receive the reflective light.

Description

Flexible physiological sensing device

The invention relates to a flexible physiological sensing device.

At present, most of the instruments on the market that measure physiological information such as human heartbeat, pulse, and blood pressure use photoplethysmography (PPG). The photoplethysmography method provides a non-invasive physiological signal measurement method, which can be divided into a transmission type or a reflection type. For example, the common heart rate wristbands on the market use reflection-type light volume change tracing to measure.

The heart rate bracelet is worn on the wrist of the test subject, uses a light emitter to emit green or red light, and then senses the light signal reflected from the body through the light sensor to analyze the heart rate. However, the heart rate bracelet cannot completely fit the skin of the person to be tested, and it is easy to cause misjudgment or failure to detect due to the movement of the bracelet during use, resulting in problems such as incorrect heart rate data. Therefore, there is a need for a flexible physiological sensing device that can fit the skin to solve the above-mentioned problems.

According to various embodiments of the present invention, a flexible type The physiological sensing device includes a flexible substrate, a first light-emitting element, and a first light-sensing element. The first light-emitting element is arranged on the flexible substrate and is configured to emit infrared light to illuminate the skin tissue, and the infrared light is reflected by the skin tissue to generate reflected light. The first light-emitting element includes a quantum dot material. The first light sensing element is arranged on the flexible substrate and adjacent to the first light emitting element, and the first light sensing element is configured to receive the reflected light.

According to some embodiments of the present invention, the flexible substrate has a first surface and a second surface. The first light-emitting element includes a quantum dot layer and an organic light-emitting diode, wherein the quantum dot layer is disposed on the first surface of the flexible substrate, and the organic light-emitting diode is disposed on the second surface of the flexible substrate Above.

According to some embodiments of the present invention, the first light-emitting element includes a quantum dot layer, an anode layer, a hole transport layer, a light-emitting layer, an electron transport layer, and a cathode layer. On the flexible substrate are a quantum dot layer, an anode layer, a hole transport layer, a light emitting layer, an electron transport layer, and a cathode layer in sequence.

According to some embodiments of the present invention, the first light-emitting element includes an anode layer, a quantum dot-doped hole transport layer, a light-emitting layer, an electron transport layer, and a cathode layer. On the flexible substrate are an anode layer, a quantum dot-doped hole transport layer, a light-emitting layer, an electron transport layer, and a cathode layer in sequence.

According to some embodiments of the present invention, the first light-emitting element includes an anode layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a cathode layer. On the flexible substrate are an anode layer, a hole transport layer, a quantum dot light-emitting layer, an electron transport layer, and a cathode layer in sequence.

According to some embodiments of the present invention, the quantum dot material includes Lead sulfide (PbS) quantum dots or iodine perovskite (Perovskite) quantum dots.

According to some embodiments of the present invention, the flexible physiological sensing device further includes a second light-emitting element located on the flexible substrate, and the first light-sensing element is located between the first light-emitting element and the second light-emitting element.

According to some embodiments of the present invention, the flexible physiological sensing device further includes a third light-emitting element, a fourth light-emitting element, and a second light-sensing element. The third light-emitting element is arranged on the flexible substrate and is adjacent to the first light-emitting element. The fourth light-emitting element is arranged on the flexible substrate and is adjacent to the second light-emitting element. The second light-sensing element is disposed on the flexible substrate, adjacent to the first light-sensing element, and located between the third light-emitting element and the fourth light-emitting element, wherein the surface area of the first light-emitting element and the second light-emitting element The surface area of the element is smaller than the surface area of the first light-sensing element, and the surface area of the third light-emitting element and the surface area of the fourth light-emitting element are respectively smaller than the surface area of the second light-sensing element.

According to some embodiments of the present invention, the first light sensing element is an organic light detector.

According to some embodiments of the present invention, the flexible physiological sensing device further includes a fixing member disposed on the flexible substrate and configured to fix the flexible physiological sensing device to skin tissue.

100‧‧‧Flexible physiological sensing device

110‧‧‧Flexible substrate

112‧‧‧First Surface

114‧‧‧Second Surface

130, 130’, 130a, 130b, 130c, 130d‧‧‧Light-emitting element

131‧‧‧Quantum dot layer

132‧‧‧Organic Light Emitting Diode

133‧‧‧Encapsulation layer

134‧‧‧Anode layer

135‧‧‧Electric hole transfer layer

135'‧‧‧Quantum dot doped hole transport layer

136‧‧‧Light-emitting layer

136'‧‧‧Quantum dot light-emitting layer

137‧‧‧Electron transport layer

138‧‧‧Cathode layer

140, 140’‧‧‧Light-emitting element

150、150’‧‧‧Light sensing element

151‧‧‧Anode

152‧‧‧Carrier layer

153‧‧‧Receptor layer

154‧‧‧Buffer layer

155‧‧‧Cathode

160‧‧‧Sensing circuit

200‧‧‧Skin tissue

300‧‧‧Electronic device

L1, L2‧‧‧Length

R1‧‧‧Light

R2‧‧‧Infrared light

W1, W2‧‧‧Width

When you read the accompanying drawings, you can fully understand all aspects of this disclosure from the following detailed description. It is worth noting that according to industry standard practice, various features are not drawn to scale. In fact, for a clear discussion, The size of various features can be increased or decreased arbitrarily.

Fig. 1 is a schematic diagram of a flexible physiological sensing device according to various embodiments of the present invention.

FIG. 2 is a schematic diagram of wearing a flexible physiological sensing device according to various embodiments of the present invention.

FIG. 3 is a schematic cross-sectional view of the light-emitting element part of the flexible physiological sensing device according to some embodiments of the present invention.

FIG. 4 is a schematic cross-sectional view of the light-emitting element part of the flexible physiological sensing device according to some embodiments of the present invention.

FIG. 5 is a schematic cross-sectional view of the light-emitting element part of the flexible physiological sensing device according to some embodiments of the present invention.

FIG. 6 is a schematic cross-sectional view of the light-emitting element part of the flexible physiological sensing device according to some embodiments of the present invention.

FIG. 7 is a schematic cross-sectional view of a light sensing device according to some embodiments of the present invention.

Hereinafter, a plurality of embodiments of the present invention will be disclosed in drawings. For clear description, many practical details will be described in the following description. However, it should be understood that these practical details should not be used to limit the present invention. That is to say, in some embodiments of the present invention, these practical details are unnecessary. In addition, for clarity, the size or thickness of the component may be exaggerated, and the drawing is not based on the original size. In addition, to simplify the illustration, Some conventionally used structures and elements will be shown in a simple schematic manner in the figure.

Spatial relative terms are used in this article, such as "below", "below", "above", "above", etc. This is to facilitate the description of the relative relationship between one element or feature and another element or feature, such as Shown in the figure. The true meaning of these relative terms in space includes other directions. For example, when the icon is turned upside down by 180 degrees, the relationship between one element and another element may change from "below" and "below" to "above" and "above". In addition, the relative narratives in space used in this article should also be interpreted in the same way.

FIG. 1 is a schematic diagram of a flexible physiological sensing device 100 according to various embodiments of the present invention. FIG. 2 is a schematic diagram of wearing the flexible physiological sensing device 100 according to various embodiments of the present invention. As shown in FIG. 1, the flexible physiological sensing device 100 includes a flexible substrate 110, a light-emitting element 130, and a light-sensing element 150. The flexible physiological sensing device 100 may also include other elements, which will be described below.

In some embodiments, the flexible substrate 110 may include polyethylene terephthalate (PET), polyimide (PI), polycarbonate (PC), Polyacrylate (PA), polyethersulfone (PES), polynorbornene (PNB), polyetheretherketone (PEEK), polyethylene naphthalate (polyethylene naphthalate, PEN) or polyetherimide (PEI) or a combination thereof, but not limited thereto. In some embodiments, the flexible substrate 110 is a light-transmitting material.

Please refer to FIG. 1 and FIG. 2 at the same time. The light emitting element 130 is disposed on the flexible substrate 110 and configured to emit infrared light (not shown) to irradiate the skin tissue 200. The infrared light emitted by the light-emitting element 130 is reflected by the skin tissue 200 to generate reflected light (not shown), wherein the light-emitting element 130 includes one or more quantum dot (QD) materials. In some embodiments, the quantum dot material includes lead sulfide (PbS) quantum dots or Perovskite quantum dots, but is not limited thereto. In some embodiments, the quantum dots may have various shapes, such as spherical, ellipsoidal, etc., but not limited thereto. In some embodiments, the infrared light has a wavelength range of about 800 nanometers to about 1100 nanometers, for example, about 940 nanometers. In the following description, examples of the structure of the light-emitting element 130 according to some embodiments of the present invention will be described with reference to FIGS. 2-6.

FIGS. 3-6 are respectively schematic cross-sectional views of the light-emitting elements 130a, 130b, 130c, and 130d in the flexible physiological sensing device 100 according to some embodiments of the present invention. Please refer to FIG. 3 first. The flexible substrate 110 has a first surface 112 and a second surface 114, wherein the first surface 112 faces the skin tissue 200 (shown in FIG. 2).

The light emitting element 130a includes a quantum dot layer 131 and an organic light emitting diode 132. The quantum dot layer 131 is disposed on the first surface 112 of the flexible substrate 110, and the organic light emitting diode 132 is disposed on the second surface 114 of the flexible substrate 110. In some embodiments, the quantum dot layer 131 It includes quantum dot materials, for example, lead sulfide (PbS) quantum dots or iodine perovskite (Perovskite) quantum dots, but not limited thereto. In some embodiments, the quantum dot layer 131 may be formed by spin coating or transfer printing of the quantum dot material on the first surface 112 of the flexible substrate 110. It should be understood that although the quantum dot layer 131 in Figure 3 has a single-layer structure, the present invention is not limited to this. In other embodiments, the quantum dot layer 131 may also be a patterned layer with multiple continuous and/or discontinuous patterns.

In some embodiments, the organic light emitting diode 132 can be any suitable organic light emitting diode, and the organic light emitting diode 132 has flexibility. As shown in FIG. 3, the light R1 emitted by the light emitting diode 132 irradiates the quantum dot layer 131 to generate infrared light R2. After that, the infrared light L2 is irradiated to the skin tissue 200 (shown in Figure 2). In some embodiments, the wavelength range of the infrared light R2 may be about 800 nanometers to about 1100 nanometers, for example, about 940 nanometers. In some embodiments, the light-emitting element 130 a further includes an encapsulation layer 133 on the second surface 114 and covers the organic light-emitting diode 132.

Please refer to FIG. 4, the light-emitting element 130b includes a quantum dot layer 131 and an organic light-emitting diode 132. In some embodiments, the material and forming method of the quantum dot layer 131 may be the same as or similar to the quantum dot layer 131 in the light-emitting element 130a. For example, using spin coating or transfer printing methods to coat lead sulfide (PbS) quantum dots or iodine perovskite (Perovskite) quantum dots and other quantum dot materials On the second surface 114 of the flexible substrate 110, a quantum dot layer 131 is formed.

The organic light emitting diode 132 is disposed on the second surface 114 of the flexible substrate 110. In some embodiments, the organic light emitting diode 132 may be the same as or similar to the organic light emitting diode 132 in the light emitting element 130a. The organic light emitting diode 132 can be any suitable organic light emitting diode, including an anode (Anode) layer 134, a hole transporting layer (HTL) 135, a light emitting layer (EML) 136, and electrons. The transfer layer 137 (electron transporting layer; ETL), and the cathode (Cathode) layer 138. In some embodiments, the light-emitting element 130b further includes an encapsulation layer (not shown) on the second surface 114, covering the organic light-emitting diode 132 and the quantum dot layer 131.

Please refer to FIG. 5, the light emitting element 130c is disposed on the second surface 114 of the flexible substrate 110. The light emitting element 130c may be an organic light emitting diode having a quantum dot material. In detail, the light emitting element 130c includes an anode layer 134, a quantum dot doped (QD doped) hole transport layer 135', a light emitting layer 136, an electron transport layer 137, and a cathode layer 138.

As shown in FIG. 5, the anode layer 134 is located on the second surface 114 of the flexible substrate 110. In some embodiments, the anode layer 134 may include any suitable anode material of an organic light emitting diode, for example, indium tin oxide (ITO), but is not limited thereto.

The quantum dot doped hole transport layer 135' is located on the anode layer 134. In some embodiments, the quantum dot-doped hole transport layer 135' may be doped with lead sulfide (PbS) quantum dots or iodine perovskite (Perovskite) quantum dots. Identical quantum dot materials, but not limited to this. The light-emitting layer 136 is located on the quantum dot-doped hole transport layer 135', and may include any suitable organic light-emitting material. The electron transport layer 137 is located on the light-emitting layer 136, and may include any suitable electron transport material. The cathode layer 138 is located on the electron transport layer 137. In some embodiments, the cathode layer 138 may include any suitable cathode material, such as aluminum (Al), but is not limited thereto.

In some embodiments, the light-emitting element 130c further includes an encapsulation layer (not shown) on the second surface 114, and covers the anode layer 134, the quantum dot doped (QD doped) hole transfer layer 135', and the light-emitting The layer 136, the electron transport layer 137, and the cathode layer 138.

Please refer to FIG. 6, the light-emitting element 130 d is disposed on the second surface 114 of the flexible substrate 110. The light emitting element 130d may be an organic light emitting diode having a quantum dot material. In detail, the light-emitting element 130d includes an anode layer 134, a hole transport layer 135, a quantum dot light-emitting layer 136', an electron transport layer 137, and a cathode layer 138.

In some embodiments, the anode layer 134, the electron transport layer 137, and the cathode layer 138 of the light-emitting element 130d may be the same as or similar to the light-emitting element 130c shown in FIG. 5. The anode layer 134 is located on the second surface 114 of the flexible substrate 110. In some embodiments, the anode layer 134 may include polydioxyethylthiophene (PEDOT), aluminum-doped zinc oxide (AZO), silver nanowire (Ag nanowire), or a combination thereof, but is not limited thereto. The hole transport layer 135 is located on the anode layer 134. In some embodiments, the hole transport layer 135 may include titanium dioxide (TiO ₂ ), indium tin oxide (ITO), or a combination thereof, but is not limited thereto.

The quantum dot light-emitting layer 136' is located on the hole transport layer 135. In some embodiments, the quantum dot light-emitting layer 136' may include one or more quantum dot materials, such as doped lead sulfide (PbS) quantum dots, iodine perovskite (Perovskite) quantum dots, or a combination thereof, but is not limited thereto . In other embodiments, one or more quantum dots in the quantum dot light-emitting layer 136' may have different shapes, different structures, and/or different sizes.

The electron transport layer 137 is located on the quantum dot light-emitting layer 136'. In some embodiments, the electron transport layer 137 includes molybdenum trioxide (MoO ₃ ), but is not limited thereto. The cathode layer 138 is located on the electron transport layer 137. In some embodiments, the cathode layer 138 may include any suitable cathode material, such as aluminum (Al), but is not limited thereto.

In some embodiments, the hole transport layer 135 and the electron transport layer 137 may also be omitted. Specifically, the light-emitting element 130d includes an anode layer 134, a quantum dot light-emitting layer 136', and a cathode layer 138. In an embodiment, the anode layer 134 may include indium tin oxide (ITO), the quantum dot light emitting layer 136' may include lead sulfide (PbS) quantum dots, and the cathode layer 138 may include lithium fluoride (LiF)/aluminum (Al )/Silver (Ag) combination. In another embodiment, the anode layer 134 may include a combination of titanium dioxide (TiO ₂ )/indium tin oxide (ITO), and the quantum dot light-emitting layer 136 ′ may include Iodide Perovskite quantum dots and poly(9, 9-dioctylfluorene (poly(9,9-dioctylfluorene); F8; PFO), and the cathode layer 138 may include a combination of silver (Ag)/molybdenum trioxide (MoO ₃ ).

In some embodiments, the light-emitting element 130d further includes an encapsulation layer (not shown) on the second surface 114 and covers the anode layer 134, the hole transport layer 135, the quantum dot light-emitting layer 136', and the electron transport layer. 137, and the cathode layer 138.

FIG. 7 is a schematic cross-sectional view of a light sensing device 150 according to some embodiments of the present invention. Please refer to FIG. 1 and FIG. 7 at the same time, the light sensing element 150 is disposed on the flexible substrate 110 and is adjacent to the light emitting element 130. The light sensing element 150 is configured to receive reflected light (not shown). Specifically, the light emitting element 130 can emit infrared light (not shown) to illuminate the skin tissue 200 (shown in Figure 2), and then the infrared light is reflected by the skin tissue 200 to generate reflected light, and the light sensing element 150 receives This reflects light. In some embodiments, the light sensing element 150 can be any light sensing element with flexibility. In some embodiments, the light sensing element 150 is an organic photodetector (OPD).

As shown in FIG. 7, the light sensing element 150 is disposed on the second surface 114 of the flexible substrate 110. The light sensing element 150 may include an anode 151, a donor layer 152, an acceptor layer 153, a buffer layer 154, and a cathode 155. In some embodiments, the anode 151 is indium tin oxide (ITO), and the cathode 155 is aluminum metal, but it is not limited thereto.

In some embodiments, the flexible physiological sensing device 100 may further include a light-emitting element 140 located on the flexible substrate 110, and the light-sensing element 150 is located between the light-emitting element 130 and the light-emitting element 140. The configuration of the light-emitting element 140 may be the same as the above-mentioned light-emitting element 130 (e.g., light-emitting element 130a, 130b, 130c, 130d) are the same or similar, so they will not be repeated here. In some embodiments, the light emitting element 130, the light emitting element 140, and the light sensing element 150 may be arranged in a matrix. In detail, the flexible physiological sensing device 100 may include a plurality of light-emitting elements 130, a plurality of light-emitting elements 140, and a plurality of light-sensing elements 150, wherein each light-sensing element 150 has one on opposite sides. The light-emitting element 130 and one light-emitting element 140, but the present invention is not limited thereto. For example, as shown in FIG. 1, the flexible physiological sensing device 100 may further include light-emitting elements 130' and 140', and a light-sensing element 150' on the flexible substrate 110. The light-emitting element 130' is adjacent to the light-emitting element 130. The light emitting element 140' is adjacent to the light emitting element 140. The light sensing element 150' is adjacent to the light sensing element 150 and is located between the light emitting element 130' and the light emitting element 140'. The structure of the light-emitting elements 130', 140' may be the same as or similar to the above-mentioned light-emitting element 130 (for example, the light-emitting elements 130a, 130b, 130c, 130d), and the structure of the light-sensing element 150' may be the same as the above-mentioned light-sensing element 150 Or similar.

Please continue to refer to Figure 1. In some embodiments, the surface area of the light emitting element 130 is smaller than the surface area of the light sensing element 150. In detail, the light-emitting element 130 has a length L1 and a width W1, the light-sensing element 150 has a length L2 and a width W2, and the surface area of the light-emitting element 130 (ie L1xW1) is smaller than the surface area of the light-sensing element 150 (ie L2xW2). In some embodiments, there is a distance between the light emitting element 130 and the light sensing element 150, and the distance can be adjusted by the light emitting power of the light emitting element. In some embodiments, the surface area of the light-emitting elements 130 and 140 may be smaller than the surface of the light-sensing element 150, respectively. The surface area of the light emitting element 130', 140' may be smaller than the surface area of the light sensing element 150' to receive the reflected light.

In other embodiments, the light-emitting element 130 and/or the light-emitting element 140 may be provided on any two sides of the light-sensing element 150, or around the light-sensing element 150, respectively. It should be noted that the shape and size of the light emitting elements 130, 130', 140, 140' and the light sensing elements 150, 150' of the present invention are not limited to those shown in Fig. 1. Specifically, the size and number of the light-emitting elements 130, 130', 140, 140' and the light-sensing elements 150, 150' can be adjusted according to the number and power of the light-emitting elements 130, 130', 140, 140'. In some embodiments, the flexible physiological sensing device 100 further includes a sensing circuit 160 connected to the light sensing element 150.

Please refer to Figure 2. In some embodiments, the flexible physiological sensing device 100 further includes a fixing member (not shown) disposed on the flexible substrate 110. The fixing member is configured to fix the flexible physiological sensing device 100 on the skin tissue 200. Specifically, in some embodiments, a transparent adhesive with good biocompatibility may be coated on the first surface 112 of the flexible physiological sensing device 100, and the flexible adhesive The physiological sensing device 100 is fixed on the inner side of the tester's wrist. In some embodiments, the flexible physiological sensing device 100 further includes a wireless receiving transmitter, and the wireless receiving transmitter can be connected to the electronic device 300 to transmit the signal obtained by the flexible physiological sensing device 100 It is processed by the electronic device 300 to obtain physiological information such as blood oxygen concentration, heart rate, blood pressure value of the subject.

As can be seen from the above implementation, compared with the prior art, the present invention The disclosed flexible physiological sensing device has the characteristic of flexibility, can completely fit the skin tissue of the test subject, and will not produce relative displacement with the skin tissue of the test subject. In addition, the flexible physiological sensing device can be accurately fitted to the part to be sensed, for example, the pulse of the wrist. Therefore, the sensing efficiency, sensitivity, and accuracy can be greatly improved. In addition, the flexible physiological sensing device of the present invention uses infrared light to detect. Compared with the prior art sensing device that uses visible light, it can avoid the interference caused by visible light in the environment, thereby improving the accuracy of sensing.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention. Anyone who is familiar with the art can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection of the present invention The scope shall be subject to the definition of the attached patent application scope.

100‧‧‧Flexible physiological sensing device

110‧‧‧Flexible substrate

130、130’‧‧‧The first light-emitting element

140、140’‧‧‧Second light-emitting element

150、150’‧‧‧Light sensing element

160‧‧‧Sensing circuit

L1, L2‧‧‧Length

W1, W2‧‧‧Width

Claims (10)

A flexible physiological sensing device, comprising: a flexible substrate having a first surface and a second surface opposite to each other; a first light-emitting element disposed on the second surface of the flexible substrate The upper part is configured to emit an infrared light that penetrates the flexible substrate from the second surface to illuminate a skin tissue, the infrared light is reflected by the skin tissue to generate a reflected light, and the first surface penetrates the flexible Substrate, wherein the first light-emitting element includes a quantum dot material; and a first light-sensing element disposed on the second surface of the flexible substrate, adjacent to the first light-emitting element, and the second light-emitting element A light sensing element is configured to receive the reflected light. The flexible physiological sensing device according to claim 1, wherein the first light-emitting element includes a quantum dot layer disposed on the first surface, and an organic light-emitting diode disposed on the second surface . The flexible physiological sensing device according to claim 1, wherein the first light-emitting element comprises: a quantum dot layer on the flexible substrate; an anode layer on the quantum dot layer; A hole transport layer on the anode layer; a light emitting layer on the hole transport layer; an electron transport layer on the light emitting layer; and a cathode layer on the electron transport layer . The flexible physiological sensing device according to claim 1, wherein the first light-emitting element comprises: an anode layer on the flexible substrate; and a quantum dot-doped hole transport layer on the anode On the layer; a light-emitting layer, located on the quantum dot doped hole transport layer; an electron transport layer, located on the light-emitting layer; and a cathode layer, located on the electron transport layer. The flexible physiological sensing device according to claim 1, wherein the first light-emitting element comprises: an anode layer on the flexible substrate; a hole transport layer on the anode layer; A quantum dot light emitting layer is located on the hole transport layer; an electron transport layer is located on the quantum dot light emitting layer; and a cathode layer is located on the electron transport layer. The flexible physiological sensing device according to claim 1, wherein the quantum dot material comprises lead sulfide (PbS) quantum dots or iodine perovskite (Perovskite) quantum dots. The flexible physiological sensing device according to claim 1, further comprising a second light-emitting element located on the flexible substrate, and the first light-sensing element is located between the first light-emitting element and the second light-emitting element Between components. The flexible physiological sensing device according to claim 7, further comprising: a third light-emitting element arranged on the flexible substrate and adjacent to the first light-emitting element; and a fourth light-emitting element arranged On the flexible substrate, adjacent to the second light-emitting element; and a second light-sensing element, disposed on the flexible substrate, adjacent to the first light-sensing element, and located Between the third light-emitting element and the fourth light-emitting element, a surface area of the first light-emitting element and a surface area of the second light-emitting element are respectively smaller than a surface area of the first light-sensing element, and the third light-emitting element A surface area of the element and a surface area of the fourth light-emitting element are respectively smaller than a surface area of the second light-sensing element. The flexible physiological sensing device according to claim 1, wherein the first light sensing element is an organic light detector. The flexible physiological sensing device according to claim 1, further comprising a fixing member disposed on the flexible substrate and configured to fix the flexible physiological sensing device to the skin tissue.

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