TWI889585B - Physiological characteristic measurement equipment - Google Patents

Abstract

A physiological characteristic measurement equipment suitable for being worn in front of eyes is provided. The physiological characteristic measurement equipment includes a light source module, a sensing module and a processing unit. The light source module is configured to provide incident linear polarization light to the eyes, wherein the incident linear polarization light has a first linear polarization. The sensing module is used to sense light to be measured coming from the eyes while the incident linear polarization light is incident to the eyes. The processing unit is connected to sensing module. The processing unit is used to provide a light intensity ratio. The light intensity ratio is a ratio of a light intensity for a first linear polarization light of the light to be measured to a light intensity for a second linear polarization light of the light to be measured, wherein the first linear polarization light has a second linear polarization and the second linear polarization light has the first linear polarization. The second linear polarization is perpendicular to the first linear polarization. The processing unit provides a physiological characteristic measurement value according to an arctangent function of the light intensity ratio.

Description

Physiological characteristics measurement equipment

The present invention relates to an optical measuring device, and in particular to a physiological characteristic measuring device.

Diabetes is a global disease, but the main blood glucose monitors (BGM) on the market currently require blood collection, which increases the discomfort of diabetic patients. In recent years, continuous glucose monitors (CGM) have been developed, which implant a glucose oxidase sensor with a soft needle under the skin to measure the subcutaneous blood sugar value to achieve the purpose of continuous detection.

On the other hand, optical blood sugar measurement equipment mostly uses Fourier transform infrared spectroscopy, Raman spectroscopy, and near infrared/middle infrared spectroscopy. However, blood collection is still necessary.

Furthermore, the above-mentioned optical monitoring instruments are difficult to miniaturize and carry with you.

The present invention provides a physiological characteristic measuring device that does not require blood collection and is easy to carry.

According to an embodiment of the present invention, a physiological characteristic measuring device is provided, which is suitable for being arranged in front of the eye. The physiological characteristic measuring device includes a light source module, a sensing module and a processing unit. The light source module is configured to provide incident linear polarization toward the eye, and the incident linear polarization has a first linear polarization. When the incident linear polarization enters the eye, the sensing module is used to sense the light to be measured from the eye. The processing unit is connected to the sensing module. The processing unit is used to provide a light intensity ratio, which is the ratio of the light intensity of the first linear polarization of the light to be measured and the light intensity of the second linear polarization of the light to be measured, wherein the first linear polarization has a second linear polarization, the second linear polarization has a first linear polarization, and the second linear polarization is perpendicular to the first linear polarization. The processing unit provides a physiological characteristic measurement value according to the inverse tangent function of the light intensity ratio.

According to another embodiment of the present invention, a physiological characteristic measuring device is provided, which is suitable for being arranged in front of the eye. The physiological characteristic measuring device includes a light source module, a sensing module and a processing unit. The light source module includes a light source and a first linear polarizer. The light source is used to provide incident light to the eye, and the incident light includes a first incident light in a first time segment and a second incident light in a second time segment. In the first time segment, the first polarizer is not on the path of the incident light, and in the second time segment, the first polarizer is on the path of the incident light. The sensing module includes a second linear polarizer. When the incident light enters the eye, the sensing module is used to sense the light to be measured from the eye to generate the light intensity of the light to be measured. The second linear polarizer is located on the path of the light to be measured, and the absorption axis of the first linear polarizer is perpendicular to the absorption axis of the second linear polarizer. The processing unit is connected to the sensing module. The processing unit is used to provide a light intensity ratio, which is the ratio of the light intensity of the light to be measured in the second time period to the light intensity of the light to be measured in the first time period. The processing unit provides a physiological characteristic measurement value based on the arc sine function of the light intensity ratio.

Based on the above, the physiological characteristics measuring device provided by the embodiment of the present invention utilizes the optical rotation of glucose and uses polarized light to measure the glucose concentration in the aqueous humor of the eye to obtain the blood sugar concentration of the subject. Compared with other invasive measuring devices, the physiological characteristics measuring device provided by the embodiment of the present invention does not require blood collection and is easy to carry.

In order to make the above features and advantages of the present invention more clearly understood, the following is a detailed description of the embodiments with the accompanying drawings.

1, 2: Physiological characteristics measurement equipment

10: Human Eye

11: Crystalline body

12: Iris

13: Aqueous humor

14: Cornea

100:Sensor module

101, 102: Sensing device

103, 104, 202: Linear polarizer

105, 203, 500: Spectroscope

110: Top point

200: Light source module

201: Light source

300: Processing unit

400: Camera device

C1: optical axis

L0: Light

L1: incident light polarization

L2, L21, L22: light to be measured

L23, L24: Linear polarization

L1: Radius of curvature

L3, L2: distance

P1, P2, P3: Linear polarization

θ1: angle of incidence

θ3: refraction angle

α: Angle of intersection

FIG1 is a schematic diagram showing the structure of a human eye; FIG2A is a schematic diagram showing a physiological characteristic measuring device according to an embodiment of the present invention; FIG2B is a schematic diagram showing a physiological characteristic measuring method according to an embodiment of the present invention; FIG3 is a schematic diagram showing a physiological characteristic measuring device according to an embodiment of the present invention.

Referring to FIG. 1 , FIG. 2A and FIG. 2B , FIG. 1 shows a schematic diagram of the structure of the human eye, FIG. 2A shows a schematic diagram of a physiological characteristic measuring device according to an embodiment of the present invention, and FIG. 2B shows a schematic diagram of a physiological characteristic measuring method according to an embodiment of the present invention. As shown in FIG. 1 , in front of the crystalline body 11 of the human eye 10 are an iris 12, aqueous humor 13 and cornea 14. The physiological characteristic measuring device 1 of this embodiment can be used to measure the glucose concentration in the aqueous humor 13. Specifically, glucose in the human body and even in nature is presented as a right-handed structure. Therefore, when polarized light passes through a glucose solution, its electric field rotates. Therefore, the physiological characteristic measuring device 1 according to the embodiment of the present invention uses polarized light to measure the glucose concentration in the aqueous humor 13 in response to the above phenomenon.

Referring to FIG. 2A , the physiological characteristic measuring device 1 includes a light source module 200, a sensing module 100, and a processing unit 300.

The light source module 200 includes a light source 201 and a linear polarizer 202. The light source 201 is used to provide light L0. After passing through the linear polarizer 202, the light L0 forms an incident linear polarization L1. The incident linear polarization L1 has a first linear polarization P1. The wavelength of the incident linear polarization L1 falls within the range of 460nm to 940nm to avoid the water volume in the aqueous humor 13 changing or absorbing the incident linear polarization L1 of a specific wavelength, changing the signal intensity, but not limited to this. After the incident linear polarization L1 enters the eye 10, it is reflected on the surface of the crystal 11 to generate the light to be measured L2.

The sensing module 100 is used to sense the light L2 to be measured from the eye 10. The light source 201 may include a laser source and a light emitting diode, but is not limited thereto. The sensing module 100 includes a linear polarizer 103, a linear polarizer 104, a spectroscope 105, a sensing device 101 and a sensing device 102. The spectroscope 105 is arranged on the path of the light L2 to be measured, and the sensing device 101 and the sensing device 102 are connected to the processing unit 300.

In some embodiments, the processing unit 300 is, for example, a central processing unit (CPU), a microprocessor (microprocessor), a digital signal processor (DSP), a programmable controller, a programmable logic device (PLD), or other similar devices or a combination of these devices, and the present invention is not limited thereto. In addition, in some embodiments, the functions of the processing unit 300 can be implemented as multiple program codes. These program codes will be stored in a memory and executed by the processing unit 300. Alternatively, in one embodiment, the functions of the processing unit 300 can be implemented as one or more circuits. The present invention does not limit the implementation of the functions of the processing unit 300 by software or hardware.

The incident linear polarized light L1 and the light to be measured L2 define an optical plane (i.e., X-Y plane), and the first linear polarization P1 is parallel to the optical plane. Part of the light to be measured L2 is formed into the first light to be measured L21 after passing through the spectroscope 105. The spectroscope 105 reflects part of the light to be measured L2 to generate the second light to be measured L22. The first light to be measured L21 passes through the linear polarizer 103 to generate linear polarized light L23, and the linear polarized light L23 has the second linear polarization P2. The second light to be measured L22 passes through the polarizer 104 to generate linear polarized light L24, and the linear polarized light L24 has the third linear polarization P3. The linear polarization direction of the linear polarized light L23 is parallel to the optical plane (parallel to the X-Y plane), and the linear polarization direction of the linear polarized light L24 is perpendicular to the optical plane (perpendicular to the X-Y plane), as shown in FIG. 2A. In general, the first linear polarization P1 and the second linear polarization P2 are parallel to the X-Y plane, and the third linear polarization P3 is perpendicular to the X-Y plane. In other words, the first linear polarization P1 and the second linear polarization P2 are horizontal polarizations with respect to the X-Y plane, and the third linear polarization P3 is vertical polarization with respect to the X-Y plane. It should be noted that the first linear polarization P1 is not limited to being parallel to the X-Y plane. In some embodiments, the first linear polarization P1 is perpendicular to the X-Y plane.

Furthermore, the sensing device 101 and the sensing device 102 are used to measure the light intensity I1 of the linear polarized light L23 and the light intensity I2 of the linear polarized light L24, respectively. The processing unit 300 can calculate the ratio of the light intensity I2 and the light intensity I1, which is the ratio of the electric field intensity of the light L2 to be measured in the vertical direction with respect to the X-Y plane and the electric field intensity in the horizontal direction with respect to the X-Y plane. The processing unit 300 further calculates the inverse tangent function of the intensity ratio, which is the angle θ (Formula 1) of the electric field of the light L2 to be measured relative to the X-Y plane, that is, the rotation angle θ of the electric field of the horizontally polarized light L1 with respect to the X-Y plane after passing through the eye. The above rotation angle θ will change according to the glucose concentration in the aqueous humor 13. In other words, the glucose concentration in the aqueous humor 13 can be measured based on the above-mentioned rotation angle θ.

Formula 1: θ = tan ^-1 I2 / I1

It should be noted that in some embodiments, the first linear polarization P1 is perpendicular to the X-Y plane. In this case, the light intensity I1 in Formula 1 is the light intensity of the linear polarization L24, and the light intensity I2 is the light intensity of the linear polarization L23. The inverse tangent function shown in Formula 1 is the rotation angle θ of the electric field of the vertical polarization light L1 in the X-Y plane after passing through the eye.

The physiological characteristic measuring device 1 may also include a camera 400, which is connected to the processing unit 300. The camera 400 may take a picture of the eye 10.

In some embodiments, the camera device 400 can be used to locate the physiological characteristic measurement device 1. In this case, the optical axis C1 of the camera device 400 is arranged on the optical plane (X-Y plane) to improve the positioning accuracy, wherein there is an angle between the incident polarized light L1 and the optical axis C1 of the camera device 400, and the angle can fall within the range of 0 degrees to 90 degrees. Specifically, the physiological characteristic measurement device 1 can be implemented as a head-mounted device and further includes a moving mechanism (not shown). The moving mechanism is connected to the processing unit 300. The processing unit 300 determines whether the physiological characteristic measuring device 1 is worn in a proper position according to the image provided by the camera 400. If the physiological characteristic measuring device 1 is not worn in a proper position, the processing unit 300 can control the moving mechanism to move the light source module 200, the sensing module 100 and the camera 400 to improve the accuracy of the measurement.

2B , when the incident angle θ ₁ of the incident polarized light L1 generated by the light source 201 on the surface of the cornea 14 and the position on the surface of the cornea meet the following conditional equation (Equation 2), the incident polarized light L1 can reach the vertex 110 of the crystal body 11 and can be further formed into the light to be measured L2 that enters the sensing device 101 and the sensing device 102.

In Formula 2 and FIG. 2B , _θ3 is the refraction angle of the incident polarized light L1 when entering the aqueous humor 13, 1.33 is the refractive index of the aqueous humor 13, _L3 is the distance between the inner layer of the cornea 14 and the vertex 110 of the lens 11 of the incident polarized light _L1 , L1 is the radius of curvature of the inner layer of the cornea 14, _L2 is the distance from the vertex 110 of the lens 11 to the center O of the radius of curvature of the inner layer of the cornea 14, and α is the angle between the line from the inner layer of the cornea 14 to the center O of the radius of curvature of the incident polarized light L1 and the line from the vertex 110 of the lens 11 to the center O of the radius of curvature.

In order to fully illustrate the various embodiments of the present invention, other embodiments of the present invention will be described below. It must be noted that the following embodiments use the component numbers and some contents of the previous embodiments, where the same numbers are used to represent the same or similar components, and the description of the same technical content is omitted. For the description of the omitted parts, please refer to the previous embodiments, and the following embodiments will not be repeated.

Referring to Figure 1 and Figure 3, Figure 3 shows a schematic diagram of a physiological characteristic measurement device according to an embodiment of the present invention.

The physiological characteristic measuring device 2 includes a light source module 200, a sensing module 100, a spectroscope 500 and a processing unit (not shown).

The light source module 200 includes a light source 201 and a spectroscope 203, and is used to provide light L0. The sensing module 100 includes a linear polarizer 103, a linear polarizer 104, a spectroscope 105, a sensing device 101, and a sensing device 102. The sensing device 101 and the sensing device 102 are connected to the processing unit. The absorption axis of the linear polarizer 103 is perpendicular to the absorption axis of the linear polarizer 104.

After passing through the linear polarizer 103, the light L0 is formed into incident linear polarization L1, and the polarization direction of the incident linear polarization L1 is parallel to the X-Y plane. After the incident linear polarization L1 enters the eye 10, it is reflected on the surface of the crystal 11 to generate the light to be measured L2, in which the incident linear polarization L1 and the light to be measured L2 overlap. For the convenience of understanding, in Figure 3, the incident linear polarization L1 and the light to be measured L2 are shown as non-overlapping.

After being reflected by the spectroscope 500, the light L2 to be measured partially penetrates and partially reflects on the spectroscope 105. The light L2 to be measured that penetrates the linear polarizer 104 enters the sensing device 102, and the sensing device 102 measures the light intensity I2 of the light L2 to be measured. The light L2 to be measured that penetrates the linear polarizer 103 is reflected by the spectroscope 203 and enters the sensing device 101, and the sensing device 101 measures the light intensity I1 of the light L2 to be measured. The processing unit calculates the ratio of the light intensity I2 to the light intensity I1 according to the above formula 1, and the ratio is the ratio of the electric field intensity of the light L2 to be measured from the eye in the vertical direction relative to the X-Y plane and the electric field intensity in the horizontal direction relative to the X-Y plane. The processing unit further calculates the inverse tangent function of the intensity ratio, which is the angle θ of the electric field of the light L2 to be measured from the eye relative to the X-Y plane (Formula 1), that is, the rotation angle θ of the electric field of the horizontally polarized light L1 relative to the X-Y plane after passing through the eye. The glucose concentration in the aqueous humor 13 can be measured based on the above rotation angle θ.

In this embodiment, the incident polarized light L1 and the light to be measured L2 both pass through the spectroscope 105 and the spectroscope 500. By configuring the spectroscope 105 and the spectroscope 500, the design margin of the physiological characteristic measuring device 2 is improved.

In addition, the physiological characteristic measuring device 2 may also include a camera device 400, and the incident polarized light L1 and the light to be measured L2 both overlap the optical axis C1 of the camera device 400. The function of the camera device 400 is as described in the above embodiment and will not be elaborated here.

Please refer to FIG. 1 and FIG. 2A again. In another embodiment of the present invention, the electric field rotation angle θ can be measured by using the physiological characteristic measuring device 1 in combination with another measuring method, wherein the absorption axis of the linear polarizer 202 is perpendicular to the absorption axis of the linear polarizer 104 and perpendicular to the XY plane, as shown in FIG. 2A. Specifically, in this embodiment, the linear polarizer 202 of the physiological characteristic measuring device 1 is not on the path of the light L0 in a first time period (for example, it is moved out of the path of the light L0), and is arranged on the path of the light L0 in a second time period (as shown in FIG. 2A). The sensing device 102 measures the light intensity I3 in the first time period and measures the light intensity I4 in the second time period. Because the electric field rotation angle θ caused by glucose in the aqueous humor 13 is very small, the rotation angle θ can be defined by equation 3 using an approximate method: θ = sin ^-1 I4/I3

In another embodiment of the present invention, the absorption axis of the linear polarizer 202 is perpendicular to the absorption axis of the linear polarizer 103 and parallel to the XY plane. The linear polarizer 202 of the physiological characteristic measuring device 1 is not on the path of the light L0 in a first time period, and is arranged on the path of the light L0 in a second time period. The sensing device 101 measures the light intensity I5 in the first time period and measures the light intensity I6 in the second time period. Because the electric field rotation angle θ caused by the glucose in the aqueous humor 13 is very small, the rotation angle θ can be defined by an approximate method using Formula 4: θ=sin ^-1 I6/I5

Based on the above, the physiological characteristics measuring device provided by the embodiment of the present invention utilizes the optical rotation of glucose and uses polarized light to measure the glucose concentration in the aqueous humor. The blood glucose concentration of the subject can be known based on the relationship between the glucose concentration in the aqueous humor and the blood glucose concentration. Compared with other invasive measuring devices, the physiological characteristics measuring device provided by the embodiment of the present invention does not require blood collection and is easy to carry.

1: Physiological characteristics measurement equipment

10: Human Eye

11: Crystalline body

100:Sensor module

101, 102: Sensing device

103, 104, 202: Linear polarizer

105: Spectroscope

200: Light source module

201: Light source

300: Processing unit

400: Camera device

C1: optical axis

L0: Light

L1: incident light polarization

L2, L21, L22: light to be measured

L23, L24: Linear polarization

P1, P2, P3: Linear polarization

Claims (16)

A physiological characteristic measuring device, suitable for being arranged in front of an eye, comprises: a light source module, configured to provide incident linear polarization toward the eye, the incident linear polarization having a first linear polarization; a sensing module, wherein when the incident linear polarization enters the eye, the sensing module is used to sense the light to be measured from the eye; and a processing unit, connected to the sensing module, wherein the processing unit is used to provide a light intensity ratio, the light intensity ratio being the ratio of the light intensity of the first linear polarization of the light to be measured and the light intensity of the second linear polarization of the light to be measured, wherein the first linear polarization has a second linear polarization, the second linear polarization has the first linear polarization, wherein the second linear polarization is perpendicular to the first linear polarization, wherein the processing unit provides a physiological characteristic measurement value according to the inverse tangent function of the light intensity ratio. A physiological characteristic measuring device as described in claim 1, wherein the incident linear polarization and the light to be measured define an optical plane, the first linear polarization is parallel to the optical plane, and the second linear polarization is perpendicular to the optical plane. A physiological characteristic measuring device as described in claim 1, wherein the incident linear polarization and the light to be measured define an optical plane, the first linear polarization is perpendicular to the optical plane, and the second linear polarization is parallel to the optical plane. The physiological characteristic measuring device as described in claim 1, wherein the light source module includes a laser source and a first linear polarizer, and the laser source provides laser light to be incident on the first linear polarizer. A physiological characteristic measuring device as described in claim 1, wherein the sensing module includes a spectroscope, a first sensing device and a second sensing device, the spectroscope is arranged on the path of the light to be measured, and the first sensing device and the second sensing device are connected to the processing unit. The physiological characteristic measuring device as described in claim 1 also includes a photographic device connected to the processing unit, the incident polarized light and the light to be measured define an optical plane, the photographic device is used to photograph the eye, and the optical axis of the photographic device is located on the optical plane. The physiological characteristic measuring device as described in claim 6 also includes a moving mechanism connected to the processing unit, and the processing unit controls the moving mechanism to move the light source module, the sensing module and the imaging device according to the image provided by the imaging device. A physiological characteristic measuring device as described in claim 6, wherein the light source module includes a laser source and a first linear polarizer, the laser source provides laser light, the laser light is incident on the first linear polarizer to generate the incident linear polarization light, and there is an angle between the incident linear polarization light and the optical axis of the imaging device, and the angle is in the range of 0 degrees to 90 degrees. A physiological characteristic measuring device as described in claim 1, wherein the wavelength of the incident polarized light falls within the range of 460 nm to 940 nm. A physiological characteristic measuring device as described in claim 1, wherein the incident polarized light and the light to be measured overlap. The physiological characteristic measuring device as described in claim 1 further includes at least one spectroscope, and the incident polarized light and the light to be measured both pass through the at least one spectroscope. A physiological characteristic measuring device as described in claim 11, wherein the number of the at least one spectroscope is 2. A physiological characteristic measuring device as described in claim 6, wherein the incident polarized light and the light to be measured overlap the optical axis of the imaging device. A physiological characteristic measuring device, suitable for being arranged in front of an eye, comprises: A light source module, comprising a light source and a first linear polarizer, wherein the light source is used to provide incident light to the eye, wherein the incident light comprises a first incident light in a first time segment and a second incident light in a second time segment, wherein in the first time segment, the first linear polarizer is not on the path of the incident light, and in the second time segment, the first linear polarizer is on the path of the incident light; A sensing module, comprising a second linear polarizer, wherein when the incident light enters the eye, the sensing module is used to sense the light to be measured from the eye to generate the light intensity of the light to be measured, the second linear polarizer is located on the path of the light to be measured, and the absorption axis of the first linear polarizer is perpendicular to the absorption axis of the second linear polarizer; and A processing unit connected to the sensing module, wherein the processing unit is used to provide a light intensity ratio, the light intensity ratio being the ratio of the light intensity of the light to be measured in the second time period to the light intensity of the light to be measured in the first time period, wherein the processing unit provides a physiological characteristic measurement value according to the arc sine function of the light intensity ratio. A physiological characteristic measuring device as described in claim 14, wherein the incident light and the light to be measured define an optical plane, the absorption axis of the first linear polarizer is parallel to the optical plane, and the absorption axis of the second linear polarizer is perpendicular to the optical plane. A physiological characteristic measuring device as described in claim 14, wherein the incident light and the light to be measured define an optical plane, the absorption axis of the first linear polarizer is perpendicular to the optical plane, and the absorption axis of the second linear polarizer is parallel to the optical plane.

Images