Electronic device, control program for electronic device, and control method for electronic device

Abstract

Provided are an electronic device, a control program for the electronic device, and a control method for the electronic device, which are capable of recognizing differences in blood circulation states such as a congestion state and a hyperemia state. The electronic device (1) includes: an image processing unit (111) that obtains first pulse wave information representing a pulse wave from a first image obtained by capturing at least a part of a body, and obtains second pulse wave information representing a pulse wave from a second image obtained by capturing a part of the body or a part corresponding to the part of the body; a data processing unit (114) that respectively obtains an average value of pulse waves within a preset time, that is, a baseline, and an average amplitude of pulse waves within a preset time, that is, a pulse wave amplitude, from the first pulse wave information and the second pulse wave information, and derives a baseline change rate and a pulse wave amplitude change rate; and a determination processing unit (115) that determines a blood circulation state based on the relationship between the baseline change rate and the pulse wave amplitude change rate.

Description

Technical Field

[0001] The present invention relates to an electronic device, a control program for an electronic device, and a control method for an electronic device. Background Art

[0002] Conventionally, as a technique for measuring blood flow on the skin surface, for example, a laser Doppler method, a laser speckle method, etc. are known.

[0003] In the laser Doppler method, blood flow is measured by using the fact that the frequency of laser light irradiated onto the skin surface is shifted when reflected by red blood cells moving in capillaries. Since the proportion of the shifted light is proportional to the number of red blood cells and the magnitude of the shift is proportional to the blood flow velocity, the blood flow volume can be calculated. In the laser speckle method, blood flow is measured by using a granular state called a speckle pattern, which is observed as a result of the coincidence of the scattered light returned when phase-uniform light such as laser light is irradiated onto a collection of scattering particles such as biological tissue. Since the speckle pattern dynamically changes as red blood cells move in capillaries, the blood flow volume can be calculated based on this change. As a measurement technique using the laser speckle method, there is, for example, a blood flow image device described in Non-Patent Document 1.

[0004] In addition, a device for extracting a pulse wave by image analysis is also known. For example, such a technique is described in Patent Document 1. Patent Document 1 describes a method for measuring the pulse wave propagation velocity, comprising: a photographing step of photographing two different parts of a human body simultaneously in a non-contact state from among a plurality of parts of the human body by a single visible light camera to generate image data that is continuous in time series; a pulse wave detection step of detecting the pulse waves of the two parts respectively based on the temporal pixel value changes of the two parts in the image data; and a pulse wave propagation velocity calculation step of calculating the pulse wave propagation velocity of the human body based on the time difference between the pulse waves of the two parts.

[0005]

Prior Art Documents

[0006]

Non-Patent Documents

[0007] Non-Patent Document 1: Omega Wave Corporation, [online], [searched on September 16, 2020], website <http: / / www.omegawave.co.jp / products / oz / principle.shtml>

[0008]

Patent Documents

[0009] Patent Document 1: Japanese Patent No. 6072893 Gazette Summary of the Invention

[0010]

Problems to be Solved by the Invention

[0011] However, in the method using the reflection of laser, although it is possible to calculate the blood flow per unit time in the tissue per unit weight, it is difficult to identify the differences in blood circulation states such as the congestion state and the hyperemia state. In addition, in the existing technologies for extracting pulse waves through image analysis, it is difficult to identify the state of blood circulation such as congestion and hyperemia, not to mention the measurement of blood flow.

[0012] An object of the present invention is to provide an electronic device, a control program for the electronic device, and a control method for the electronic device that can measure blood flow based on a moving image captured by an ordinary camera and identify the differences in blood circulation states such as the congestion state and the hyperemia state.

[0013]

Means for Solving the Problem

[0014] To achieve the above object, an electronic device according to an aspect of the present invention includes: an image processing unit that acquires first pulse wave information representing a pulse wave from a first image obtained by imaging a part of a subject's body during a first period, and acquires second pulse wave information representing a pulse wave from a second image obtained by imaging the part of the subject's body during a period after the first period, i.e., a second period; a data processing unit that respectively acquires a baseline of the pulse wave and a pulse wave amplitude from the first pulse wave information and the second pulse wave information, and derives a baseline change index representing the change in the baseline in the first pulse wave information and the second pulse wave information, and a pulse wave amplitude change index representing the change in the pulse wave amplitude in the first pulse wave information and the second pulse wave information; and a determination processing unit that determines the blood circulation state based on the relationship between the baseline change index and the pulse wave amplitude change index.

[0015]

Effects of the Invention

[0016] According to the electronic device, the control program for the electronic device, and the control method for the electronic device of the present invention, it is possible to identify the differences in blood circulation states such as the congestion state and the hyperemia state. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural diagram showing the structure of a measurement system according to an embodiment of the present invention.

[0018] Figure 2 It is a structural diagram showing the external structure of an electronic device and a imaging unit according to an embodiment of the present invention.

[0019] Figure 3 It is a block diagram showing the hardware structure of an electronic device according to an embodiment of the present invention.

[0020] Figure 4 It is shown withFigure 2 Structural diagram of the front appearance of an electronic device according to different embodiments.

[0021] Figure 5 It represents Figure 2 Structural diagram of the back appearance of an electronic device according to different embodiments.

[0022] Figure 6 It is a functional block diagram of the functional structure for performing measurement processing among the functional structures of the electronic device according to an embodiment of the present invention.

[0023] Figure 7 It is a graph showing the time change of the converted luminance before the cold water load measured by the electronic device according to an embodiment of the present invention.

[0024] Figure 8 It is a graph showing the time change of the converted luminance after the cold water load measured by the electronic device according to an embodiment of the present invention.

[0025] Figure 9 It is a graph schematically showing the pulse wave amplitude measured by the electronic device according to an embodiment of the present invention.

[0026] Figure 10 It is a graph obtained by magnifying the waveform of the time change of the converted luminance before the cold water load measured by the electronic device according to an embodiment of the present invention.

[0027] Figure 11 It is a graph obtained by magnifying the waveform of the time change of the converted luminance after the cold water load measured by the electronic device according to an embodiment of the present invention.

[0028] Figure 12 It is a graph showing the time change of the converted luminance of the target part of the left arm measured by the electronic device according to an embodiment of the present invention.

[0029] Figure 13 It is a graph showing the time change of the converted luminance of the target part of the right arm receiving vaccination measured by the electronic device according to an embodiment of the present invention.

[0030] Figure 14 It is a graph obtained by magnifying the waveform of the time change of the converted luminance of the target part of the left arm measured by the electronic device according to an embodiment of the present invention.

[0031] Figure 15 It is a graph obtained by magnifying the waveform of the time change of the converted luminance of the target part of the right arm receiving vaccination measured by the electronic device according to an embodiment of the present invention.

[0032] Figure 16 It is a table showing the results of comparing the before and after of the cold water load and the presence or absence of vaccination by the electronic device according to an embodiment of the present invention.

[0033] Figure 17 It is a graph with the baseline change rate on the horizontal axis and the pulse wave amplitude change rate on the vertical axis based on the measurement results of the electronic device according to an embodiment of the present invention.

[0034] Figure 18 It is a graph showing the judgment criteria for the blood circulation state of the electronic device according to an embodiment of the present invention.

[0035] Figure 19 It is a diagram showing an example of the measurement results displayed on the display unit of the electronic device according to an embodiment of the present invention.

[0036] Figure 20 It is a flowchart explaining the first half of the measurement process executed by the electronic device according to an embodiment of the present invention.

[0037] Figure 21 It is a flowchart explaining the second half of the measurement process executed by the electronic device according to an embodiment of the present invention.

[0038] Figure 22 It is a schematic diagram showing the state during an experiment using the electronic device according to an embodiment of the present invention.

[0039] Figure 23 It is an image when the hand height is low measured by the two-dimensional laser blood flowmeter of the comparative example.

[0040] Figure 24 It is an image when the hand height is high measured by the two-dimensional laser blood flowmeter of the comparative example.

[0041] Figure 25 It is a graph showing the time change of the converted brightness when the hand height is low measured by the electronic device according to an embodiment of the present invention.

[0042] Figure 26 It is a graph showing the time change of the converted brightness when the hand height is high measured by the electronic device according to an embodiment of the present invention.

[0043] Figure 27 It is a graph obtained by magnifying the waveform of the time change of the converted brightness when the hand height is low measured by the electronic device according to an embodiment of the present invention.

[0044] Figure 28It is a graph that magnifies the waveform of the temporal change in the conversion luminance when the hand height measured by the electronic device according to an embodiment of the present invention is high. Detailed Embodiment

[0045] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0046] [Overview of Embodiment]

[0047] The electronic device 1 according to an embodiment of the present invention is a measuring device that measures the blood circulation state based on an image obtained by photographing a measurement site of a user.

[0048] [System Structure]

[0049] Figure 1 It is a block diagram showing the overall structure of the measurement system S including the electronic device 1 according to the present embodiment. As Figure 1 shown, the measurement system S includes a plurality of electronic devices 1, a network 2, and a server group 3. The number of electronic devices 1 is not particularly limited, and the measurement system S may include n (n is an arbitrary natural number) electronic devices 1. In the following description, when not particularly distinguishing the n electronic devices 1 for explanation, the trailing letter of the symbol is omitted, and it is simply referred to as "electronic device 1".

[0050] The electronic device 1 is a computer that measures the blood circulation state of a user based on an image. The electronic device 1 is communicably connected to each server included in the server group 3 via the network 2.

[0051] The network 2 is realized, for example, by any one of the Internet, a LAN (Local Area Network), a mobile phone network, or a network combining them.

[0052] The server group 3 includes various servers that cooperate with the electronic device 1. For example, the server group 3 includes an authentication server for authenticating the users of the electronic device 1. In addition, for example, the server group 3 includes an application distribution server that distributes application software for realizing the functions of the electronic device 1. Furthermore, for example, the server group 3 includes a measurement data storage server that stores information such as setting information related to the user, the usage history of the user's electronic device 1, that is, the user's profile information.

[0053] In addition, Figure 1 the measurement system S shown is merely an example, and servers having other functions may also be included in the server group 3. In addition, the multiple servers included in the server group 3 may be realized by separate server devices respectively, or may be realized by a single server device.

[0054] [Electronic device]

[0055] Next, with reference to Figure 2 and Figure 3 , an example of the electronic device 1 and the imaging unit 6 will be described. Figure 2 FIG. is a structural diagram showing the external structure of the electronic device 1 and the imaging unit 6 according to an embodiment of the present invention. Figure 3 FIG. is a block diagram showing the hardware structure of the electronic device 1 according to an embodiment of the present invention.

[0056] As Figure 2 and Figure 3 shown, the electronic device 1 includes: a housing 5, a CPU (Central Processing Unit) 11, a ROM (Read Only Memory) 12, a RAM (Random Access Memory) 13, a bus 14, an input / output interface 15, an imaging unit 6, an input unit 17, an output unit 18, a storage unit 19, a communication unit 20, a driver 21, and a battery 22.

[0057] Figure 2 The housing 5 shown houses various electronic components. As Figure 2 shown, the electronic device 1 of the present embodiment is a notebook computer, and the housing 5 is configured to be foldable.

[0058] Figure 3 The CPU 11 shown is a processor that executes various processes according to a program recorded in the ROM 12 or a program loaded from the storage unit 19 to the RAM 13.

[0059] The RAM 13 also appropriately stores data and the like required when the CPU 11 executes various processes.

[0060] The CPU 11, ROM 12, and RAM 13 are connected to each other via the bus 14. The bus 14 is also connected to the input / output interface 15. The input unit 17, output unit 18, storage unit 19, communication unit 20, driver 21, and battery 22 are connected to the input / output interface 15.

[0061] The input unit 17 is a part that accepts operation inputs based on a user. The input unit 17 is implemented by, for example, a plurality of keys, a keyboard, or the like.

[0062] The output unit 18 is a part that displays various information to the user by displaying various information. The output unit 18 includes a liquid crystal display or the like, and displays an image corresponding to the image data output by the CPU 11.

[0063] The storage unit 19 includes a semiconductor memory such as a DRAM (Dynamic Random Access Memory) and stores various types of data.

[0064] The communication unit 20 performs communication control for enabling the CPU 11 to communicate with other devices (such as each server included in the server group 3) via the network 2.

[0065] The drive 21 includes an interface capable of mounting a removable medium 100. A removable medium 100 such as a magnetic disk, an optical disk, an optical magnetic disk, or a semiconductor memory is appropriately mounted in the drive 21. Various types of data such as a program and image data for executing the composite display process described later are stored in the removable medium 100. Various types of data such as the program and image data read from the removable medium 100 by the drive 21 are installed in the storage unit 19 as needed.

[0066] The battery 22 supplies power to each unit and is configured to be rechargeable by being connected to an external power source. In a state where the electronic device 1 is not connected to an external power source, the electronic device 1 operates using the power of the battery 22.

[0067] [Imaging unit]

[0068] The imaging unit 6 is a component for capturing an image of a subject and is electrically connected to the electronic device 1. Figure 2 In the figure, an example of being connected to the input / output interface 15 of the electronic device 1 via a connection unit 30 such as USB is shown, but the connection form is not limited to wired and can also be wireless.

[0069] The imaging unit 6 includes: a main body unit 31, a cover 34 disposed on the front side of the main body unit 31, an optical lens unit 32 disposed inside the cover 34, and an illumination unit 33 disposed inside the cover 34.

[0070] The main body 31 incorporates an image sensor and the like. The image sensor incorporated in the main body 31 includes a photoelectric conversion element, an AFE (Analog Front End), and the like. The photoelectric conversion element includes, for example, a CMOS (Complementary Metal Oxide Semiconductor) type photoelectric conversion element. An object image is incident on the photoelectric conversion element from the optical lens unit. Then, the photoelectric conversion element performs photoelectric conversion (shooting) on the object image, accumulates the image signal for a certain period of time, and sequentially provides the accumulated image signal to the AFE as an analog signal. The AFE performs various signal processes such as A / D (Analog / Digital) conversion processing on the analog image signal. Through various signal processes, a digital signal is generated and output as the output signal of the imaging unit 6. Such an output signal of the imaging unit 6 is appropriately provided to the CPU 11 and the like. A peripheral circuit for modulating setting parameters such as the focus point, exposure, and white balance is also provided in the main body 31 as needed.

[0071] The optical lens unit 32 includes lenses for condensing light, such as a focusing lens and a zoom lens, for shooting an object. The illumination unit 33 includes an LED.

[0072] The cover 34 is disposed on the front side of the main body 31 and is configured in a cylindrical shape. The optical lens unit 32 and the illumination unit 33 of the present embodiment are disposed inside the cover 34.

[0073] By setting the imaging unit 6 to a state where the front end of the cover 34 is pressed against the skin of the object, the influence of external light can be suppressed. As a result, it is possible to avoid a situation where the distance from the optical lens unit 32 to the measurement site becomes unstable due to the body movement of the object or the like, or the illumination conditions become unstable due to changes in brightness or the like. The influence of changes in the surrounding brightness can be effectively suppressed, and the positional relationship between the optical lens unit 32 and the object is also easily kept fixed, thereby significantly improving the measurement accuracy and stability.

[0074] The structure of the electronic device 1 and the imaging unit 6 has been described above. However, this structure is merely an example. For example, the imaging unit 6 may include a general-purpose camera or a web camera, and the electronic device 1 may also include a tablet computer other than a laptop computer.

[0075] [The second electronic device 1

[0076] Next, with reference to Figure 4 and Figure 5 , an electronic device 1a having a structure different from that of the above-described electronic device 1 will be described. Figure 4 is a structural diagram showing the front external structure of the electronic device 1a according to a different embodiment from Figure 2 , Figure 5It is a structural diagram showing the appearance structure of its back side.

[0077] Figure 4 and Figure 5 The electronic device 1a shown is a smartphone. The electronic device 1a has substantially the same hardware structure as the electronic device 1 which is a laptop computer. That is, the same structure as the electronic components described in Figure 3 is built in the housing 5a of the electronic device 1a. For example, as shown in Figure 4 , on the front side of the housing 5a of the electronic device 1a, a touch panel display 35 is arranged, and this touch panel display 35 functions as the input unit 17 and the output unit 18 of Figure 3 . In addition, as shown in Figure 5 , on the back side of the housing 5a, an in-built camera 36 is integrally held. By installing a close-up lens 37 on the in-built camera 36, this in-built camera 36 functions as the imaging unit 6 of Figure 3 . In addition, the in-built camera 36 has a plurality of lenses 32a equivalent to the optical lens unit 32 and a light unit 33a equivalent to the lighting unit 33.

[0078] [Functional Structure]

[0079] Next, the functional structure of the above-mentioned electronic device 1 or electronic device 1a will be described. Figure 5 It is a functional block diagram showing the functional structure for performing measurement processing among the functional structures of the electronic device 1. The so-called measurement processing is a series of processes in which the electronic device 1 displays a measurement result based on the change in the biometric information value obtained from the user.

[0080] As shown in Figure 5 , in the CPU 11 which is the control unit, an image processing unit 111, a display processing unit 112, an input processing unit 113, a data processing unit 114, a judgment processing unit 115, and a communication processing unit 116 function. Hereinafter, each functional structure will be described.

[0081] The image processing unit 111 is an image processing function for processing the image captured by the imaging unit 6 and extracting pulse wave information representing the pulse wave from the image. The image processing unit 111 obtains pulse wave information from the first image obtained by photographing a user in a certain state and obtains pulse wave information from the second image obtained by photographing a user in another state in order to measure the change in the blood circulation state. For example, a certain state is the state before the event, and the other state is the state after the event.

[0082] The event can be various actions such as massage for promoting blood flow, application of skin care products with the effect of promoting blood circulation, various actions in beauty care such as sports or leisure where the change in blood flow is predicted, and medical treatments such as vaccination.

[0083] The display processing unit 112 is a display processing function that performs processing such as generating the content to be displayed on the output unit 18. The display processing unit 112 outputs the result of comparing the pulse wave information before and after an event to the output unit 18 as a measurement result. The measurement result output to the output unit 18 may include information indicating the blood circulation state and a tone dynamic image that visually represents the blood flow change dynamically. For the tone dynamic image, for example, the measurement site is divided into small grid-like areas, and the blood flow change is represented by the change in tone for each small area.

[0084] The input processing unit 113 processes the input operations of the user. The data processing unit 114 is an input processing function that performs image processing of various data required for image analysis and the like. The communication processing unit 116 also performs communication processing with the server group 3 on the cloud and the like.

[0085] The data processing unit 114 is a data processing function that obtains the pulse wave information of the user from the image obtained by the image processing unit 111. In the present embodiment, the data processing unit 114 derives the relative change (difference) from the respective pulse wave information before and after an event at the same part of the same user. In addition, the relative change (difference) is derived from the respective pulse wave information at the corresponding part (for example, the left arm) of the part (for example, the right arm) corresponding to the same user.

[0086] The determination processing unit 115 is a determination processing function that performs processing for determining the blood circulation state based on the relative change derived by the data processing unit 114. The processing for determining the blood circulation state performed by the data processing unit 114 and the determination processing unit 115 will be described later.

[0087] The communication processing unit 116 communicates with, for example, the authentication server included in the server group 3. Thereby, the user performing the display processing is authenticated. Further, the communication processing unit 116 communicates with, for example, the measurement data storage server included in the server group 3, thereby updating the profile information of the user in the display processing.

[0088] [Image Analysis]

[0089] Next, the image analysis will be described. The image processing unit 111 utilizes the property that hemoglobin in the blood absorbs green light well to obtain information related to blood flow such as pulse and pulse wave. The wavelength of the green signal is generally 495 - 570 nm, and hemoglobin has a relatively high absorption coefficient in the vicinity of 550 - 660 nm. When the blood flow rises, the amount of blood on the skin surface increases, so the amount of hemoglobin per unit time increases. Therefore, compared with before the blood flow rises, more green signals are absorbed by hemoglobin. Therefore, the brightness of the green signal detected when the blood flow rises decreases.

[0090] The image processing unit 111 obtains the time change of the brightness of the green signal by obtaining the brightness of the green signal per unit time. The unit time is, for example, the frame rate of a moving image, and the brightness of the green signal can be obtained for each image that is temporally continuous and constitutes the image. In addition, it is preferable to dispose RGB filters in front of the imaging element of the imaging unit 6 to derive the brightness values of the respective pixels of RGB. In this case, the light that passes through the green filter is the brightness value. Even if the sensitivity of the imaging element is flat with respect to the wavelength, the wavelength band can be narrowed to some extent by the above filter, so that the green signal (green light) can be detected with high accuracy.

[0091] In the present embodiment, since it is easy to grasp the rise of blood flow perceptually, conversion processing is performed such that the brightness value becomes higher when the blood flow rises. More specifically, in the case of detecting the brightness of the green signal using an image sensor that outputs 8 bits for each of RGB colors, the detected brightness value of the green signal is subtracted from the maximum value 255 of the brightness value. The brightness obtained by this subtraction operation is used as the converted brightness.

[0092] In order to reflect the brightness of the green signal at a plurality of positions at the measurement site, the converted brightness is derived by various methods such as the mode value, the median value, and the average value. For example, the average value of the green signals of all the pixels in the range of the measurement site is obtained per unit time as the converted brightness, and the time series information of the converted brightness thus extracted becomes pulse wave information.

[0093] The data processing unit 114 obtains the average value of the converted brightness for a specified time (a preset time) from the pulse wave information (converted brightness). Hereinafter, the average value of the converted brightness within the specified time will be described as the baseline. In addition, the data processing unit 114 obtains the amplitude of the converted brightness from the pulse wave information (converted brightness). Hereinafter, the amplitude of the converted brightness for the specified time will be described as the pulse wave amplitude.

[0094] The data processing unit 114 of the present embodiment determines the blood circulation state based on the change in the baseline and the change in the pulse wave amplitude before and after the event. Next, specific examples of the change in the baseline and the change in the pulse wave amplitude will be described.

[0095] First, with reference to Figure 7 and Figure 8 , an example of the baseline will be described. Figure 7 is a graph showing the time change of the converted brightness before cold water loading measured by the electronic device 1 according to an embodiment of the present invention. Figure 8 is a graph showing the time change of the converted brightness after cold water loading measured by the electronic device 1 according to an embodiment of the present invention.

[0096] Figure 7 and Figure 8In this case, the palm is used as the measurement site, and providing a cold water load to the palm is used as the event. Here, the cold water load means a state of immersing the wrist in cold water at 15°C for 1 minute. In addition, Figure 7 and Figure 8 in the chart, the vertical axis is the converted luminance and the horizontal axis is the time (seconds). If we compare Figure 7 and Figure 8 , it can be seen that the baseline of the pulse wave information represented by the dash-dot line rises after the cold water load.

[0097] Next, the pulse wave amplitude will be described. Figure 9 is a chart schematically showing the pulse wave amplitude (PA; Pulse Amplitude) measured by the electronic device 1 according to an embodiment of the present invention. As Figure 9 shown, the pulse wave information analyzed from the image represents a waveform showing periodicity within a certain range of the pulse wave amplitude. This pulse wave amplitude means the difference between the adjacent maximum value and minimum value of the pulse wave signal.

[0098] The region preferably used for obtaining the pulse wave amplitude is a region without outliers and with a stable amplitude. For example, in the case where outliers exceeding a preset threshold are detected, etc., the pulse wave information is obtained excluding the outliers. Or, it may be indicated during shooting that the image cannot be properly obtained, and reshooting is performed to obtain appropriate pulse wave information. Or, the pulse wave after a specified time has elapsed since the start of shooting may be used for the derivation of the amplitude. Or, the outliers may be removed from the pulse wave obtained within a specified time to derive the amplitude. In this way, various methods can be applied to the derivation of the amplitude.

[0099] Referring to Figure 10 and Figure 11 , specific examples of the pulse wave amplitude will be described. Figure 10 is a chart showing an enlarged waveform of the time change of the converted luminance before the cold water load measured by the electronic device 1 according to an embodiment of the present invention. Figure 11 is a chart showing an enlarged waveform of the time change of the converted luminance after the cold water load measured by the electronic device 1 according to an embodiment of the present invention.

[0100] Figure 10 corresponds to the chart of Figure 7 , Figure 11 corresponds to the chart of Figure 8 . For the scale of the converted luminance, Figure 10 is 82 - 86, Figure 11 is 92 - 96, and the range widths are aligned to 4 respectively. Figure 10 and Figure 11 in the shown charts, the beats of the pulse wave information can be observed one by one. In addition, if we compare Figure 10 andFigure 11 , it can be seen that the pulse wave amplitude decreases after cold water load.

[0101] It is expected that cooling the hand will reduce blood flow, but the baseline rises due to the cooling load, resulting in a decrease in the pulse wave amplitude.

[0102] Next, refer to Figures 12 to 15 , a specific example of an event different from the cooling water load is described. The event described below is the result of measuring the target parts of the right and left arms of a certain subject. The subject received a flu vaccination on the right arm the day before the measurement, and the part became red and swollen.

[0103] Describe the trend of the baseline. Figure 12 is a graph showing time changes in the converted brightness of the target part of the left arm measured by the electronic device 1 according to one embodiment of the present invention. Figure 13 is a graph showing the time change of the converted brightness of the target part of the right arm that received the vaccination. Figure 12 and Figure 13 It can be seen that the baseline of the target site on the right arm that received the vaccination increased significantly compared to the baseline of the target site on the left arm.

[0104] The trend of the pulse wave amplitude is described. Figure 14 1 is a graph showing an enlarged waveform of a time change in converted brightness of a target part of a left arm measured by the electronic device 1 according to an embodiment of the present invention. Figure 15 This is a graph that enlarges the waveform of the time change of the converted brightness of the target part of the right arm. Figure 14 and Figure 15 It can be seen that the pulse wave amplitude of the target site of the right arm receiving the vaccination has increased significantly compared to the pulse wave amplitude of the target site of the left arm.

[0105] From these results, it can be seen that the target site on the right arm that received the vaccination and became red and swollen had a larger rise in the baseline and an increase in the pulse wave amplitude than the target site on the left arm that was not red and swollen.

[0106] Figure 16 TABLE 1 is a table showing the results of comparing the cold water load before and after and the presence or absence of vaccination using an electronic device according to one embodiment of the present invention. Figure 16 As shown in the table, it can be seen that the baseline rises and the pulse wave amplitude decreases in the cold water load, while in the case of redness and swelling in other cases, the baseline rises significantly and the pulse wave amplitude also increases. That is, the baseline and the pulse wave amplitude may not necessarily have the same increasing trend due to different blood circulation states.

[0107] In the prior art such as a laser Doppler flowmeter and a laser speckle flowmeter, only one value of the blood flow rate of the measurement site as the object is obtained. However, in the electronic device 1 of the present embodiment, two different values of the change in the baseline and the change in the pulse wave amplitude can be acquired. It is not just a simple increase or decrease in blood flow rate, and a more detailed blood circulation state can be inferred.

[0108] [Judgment of blood circulation state]

[0109] Next, a method for judging the blood circulation state using the baseline and the pulse wave amplitude will be described. Figure 17 It is a graph with the baseline change rate (baseline change index) based on the measurement result of the electronic device 1 according to an embodiment of the present invention on the horizontal axis and the pulse wave amplitude change rate (pulse wave amplitude change index) on the vertical axis. The baseline change rate can be derived according to the following formula 1, and the pulse wave amplitude change rate can be derived according to the following formula 2. In addition, Figure 17 The black dots in it represent examples of plotting the results of formula 1 and formula 2 on this graph.

[0110] Baseline change rate = (BL2 / BL1) - 1... (Formula 1)

[0111] BL1: Baseline of the pulse wave information in the first measurement

[0112] BL2: Baseline of the pulse wave information in the second measurement

[0113] Pulse wave amplitude change rate = (PA2 / PA1) - 1... (Formula 2)

[0114] PA1: Average value of the measured values of the pulse wave amplitude during n seconds in the first measurement

[0115] PA2: Average value of the measured values of the pulse wave amplitude during n seconds in the second measurement

[0116] Here, the meanings of the baseline and the pulse wave amplitude are studied. As described above, the principle of extracting the pulse wave from the image brightness is to capture the temporal change in the brightness of the green light absorbed by hemoglobin. Therefore, it is considered that the baseline is approximately proportional to the average amount of hemoglobin in the object part during the measurement period. That is, the change in the baseline can be interpreted as the change in the average blood volume of the measurement site. In contrast, the pulse wave amplitude itself represents the pulsation of the pulse, so the change in the pulse wave amplitude can be interpreted as the change in the pulsation intensity.

[0117] Figure 18 It is a graph showing the judgment criteria for the blood circulation state of the electronic device 1 according to an embodiment of the present invention. Figure 18 It is shown that Figure 17A graph of the blood circulation state in which the horizontal axis changes from the baseline change rate to the blood volume change rate, and the vertical axis changes from the pulse wave amplitude change rate to the pulsation change rate. By the changes in blood volume and pulsation, the changes in blood flow can be inferred.

[0118] Next, the blood circulation state judged based on the graph shown in Figure 18 will be described. In this example, after all the measurements are completed, the determination processing unit 115 sets the x coordinate on the horizontal axis representing the level (degree) of the blood volume change rate based on the derived baseline change rate. In addition, the data processing unit 114 sets the y coordinate on the vertical axis representing the level (degree) of the pulsation change rate. And the data processing unit 114 sets the derived base change rate as the x coordinate and the pulse wave amplitude change rate as the y coordinate to plot the derived result as (x, y) coordinates. The determination processing unit 115 determines the blood circulation state based on the plotted position.

[0119] For example, when there is almost no change in blood volume but the pulsation increases and it is plotted at the position in the center shown by the black dot in Figure 18 , it can be determined that the blood circulation state is an increase in blood flow. On the other hand, when there is almost no change in blood volume but the pulsation decreases, it can be determined that the blood circulation state is a decrease in blood flow. The determination processing unit 115 determines that there is almost no change (less) in blood volume, for example, in the case of the vicinity range around the baseline change rate of 1. The vicinity range in this case is a numerical range preset according to experience or measured values.

[0120] When both the blood volume and pulsation increase and it is plotted within the specified range in the first quadrant in the upper right, if the first measurement is in a poor blood circulation state, it is considered that the poor blood circulation is improved in the second measurement. In addition, in this case, if the first measurement is in a normal state, it is considered that there is a tendency of congestion in the second measurement. The specified range in this specification is a range that can also be determined by numerical values and mathematical formulas. The determination processing unit 115 can determine the blood circulation state based on whether the plot enters the specified range.

[0121] In addition, an appropriate method can be adopted for the method of determining whether it is a poor blood circulation state or a normal state. For example, the determination processing unit 115 can determine based on whether the measured values such as the pulse wave information, baseline, and pulse wave amplitude obtained from the first image exceed a preset threshold value, and the determination processing unit 115 can also make a determination by comparing with the user's past measured values.

[0122] When the blood volume decreases while the pulsation increases and it is plotted within the specified range in the second quadrant in the upper left, it is considered that the congestion is improved.

[0123] When drawing within a specified range in the third quadrant in the lower left where both the blood volume and pulsation decrease, it is considered that if the first measurement shows a tendency towards congestion, the congestion is improved in the second measurement. Additionally, in this case, it is considered that if the first measurement is in the normal state, there is a tendency towards poor blood circulation in the second measurement.

[0124] In addition, an appropriate method can be adopted to determine whether it is a congestion tendency state or a normal state. For example, the determination processing unit 115 can make a determination by whether measurement values such as the pulse wave information, baseline, and pulse wave amplitude obtained from the first image exceed a preset threshold value, or the determination processing unit 115 can also make a determination by comparing with the user's past measurement values.

[0125] When the blood volume increases while the pulsation decreases and drawing is performed within a specified range in the fourth quadrant in the lower right, it is considered to be a tendency towards stasis.

[0126] In this way, not only can the blood flow as a numerical value be inferred, but also its blood circulation state can be inferred together. The display processing unit 112 executes the process of Figure 18 displaying the chart (figure) shown as the measurement result on the output unit 18.

[0127] It can also execute the process of Figure 18 displaying the information shown together with Figure 19 the information shown. Figure 19 It is a figure showing an example of the measurement result (image) displayed on the output unit 18 of the electronic device 1 according to an embodiment of the present invention. Figure 19 In the image shown, the box 201 represents the average blood volume of the first and second times as a bar chart, and the box 202 represents the pulsation of the first and second times as a bar chart. Additionally, below the boxes 201 and 202 in the image, there is a text 203 displaying messages such as "Average blood volume: 1.1 times", "Strength of pulsation: 1.3 times", and "Blood flow increases." The display processing unit 112 executes the following process: generating Figure 19 the image shown, and displaying this image alone or together with the image of the Figure 18 chart (figure) shown on the output unit 18.

[0128] In addition, the determination processing unit 115 may determine that the blood circulation state cannot be appropriately determined when the baseline change rate or the pulse wave amplitude change rate becomes an outlier exceeding the set range of the graph. For example, the determination processing unit 115 may determine an abnormal state when the first time is in the normal state and the baseline change rate and the pulse wave amplitude change rate are 3 or more. In this case, the following structure may also be adopted: the display processing unit 112 executes processing to display a message indicating that the blood circulation state cannot be appropriately determined on the output unit 18, and reports the abnormality to the user.

[0129] [Measurement processing flow]

[0130] Next, refer to Figure 20 and Figure 21 to describe the measurement processing flow. Figure 20 and Figure 21 is a flowchart for explaining the measurement processing flow executed by the electronic device 1 having the Figure 6 functional structure. Figure 1 of the

[0131] As Figure 20 shown, if the input processing unit 113 receives information indicating that the user operates via the input unit 17 to start the first measurement, it sends an instruction to start dynamic image shooting to the image processing unit 111 (step S101).

[0132] If the image processing unit 111 receives the start instruction from the input processing unit 113, the imaging unit 6 starts shooting the first dynamic image including the measurement site (step S102). Next, the image processing unit 111 executes processing to extract the first image pulse wave (pulse wave information) (step S103).

[0133] Next, the image processing unit 111 determines whether the condition for ending the measurement is satisfied (step S104). The condition for ending the measurement is, for example, whether the shooting has continued for a preset set time. If the image processing unit 111 does not satisfy the condition for ending the measurement, it continues shooting until the condition is satisfied (step S104: No). If the image processing unit 111 satisfies the condition for ending the measurement, it proceeds to step S105 (step S104: Yes).

[0134] In step S105, the image processing unit 111 ends the image pulse wave extraction processing and ends the dynamic image shooting based on the imaging unit 6 (step S105). If the image pulse wave extraction processing and the dynamic image shooting are ended, the data processing unit 114 performs analysis processing on the first data obtained by the image processing unit 111 in order to determine the blood circulation state (step S106). Next, the data processing unit 114 saves the data including the first measurement result in the storage unit 19 (step S107).

[0135] If the data including the measurement result of the first time is stored in the storage unit 19, the input processing unit 113 performs the process of waiting for the second operation (step S108). Through this process, the electronic device 1 is in a state where it can receive the start operation of the second time via the input unit 17. The input processing unit 113 waits for whether the start operation is detected (step S109). The input processing unit 113 continues to be in an operable state until the start operation is detected (step S109: No). When the input processing unit 113 detects the start operation, the process proceeds to Figure 21 step S110 (step S109: Yes).

[0136] In step S110, the image processing unit 111 starts shooting a second dynamic image including the measurement site by the imaging unit 6 (step S110). Next, the image processing unit 111 performs the process of extracting the image pulse wave (pulse wave information) from the second image (step S111).

[0137] Next, the image processing unit 111 determines whether the condition for ending the measurement is satisfied (step S112). The condition for ending the measurement is, for example, whether the shooting has continued for a preset time. When the condition for ending the measurement is not satisfied, the image processing unit 111 continues shooting until the condition is satisfied (step S112: No). When the condition for ending the measurement is satisfied, the image processing unit 111 makes the process proceed to step S113 (step S112: Yes).

[0138] In step S113, the image processing unit 111 ends the image pulse wave extraction process and also ends the dynamic image shooting based on the imaging unit 6 (step S113). If the image pulse wave extraction process and the dynamic image shooting are ended, the data processing unit 114 performs the analysis process of the second data obtained by the image processing unit 111 in order to determine the blood circulation state (step S114).

[0139] The determination processing unit 115 performs the following process: comparing the data including the measurement result of the first time saved in step S107 with the data including the measurement result of the second time, and determining the blood circulation state (step S115). In the present embodiment, based on the baseline change rate and the pulse wave amplitude change rate derived by the data processing unit 114, the determination processing unit 115 draws the measurement result as Figure 18 the chart shown, and thereby determines the blood circulation state.

[0140] After the process of step S115, the display processing unit 112 performs the process of displaying the measurement result including the determined blood circulation state on the output unit 18, and displays the measurement result to the user (step S116). For example, Figure 18 andFigure 19 The content shown is displayed on the output unit 18. Through the series of processes described above, the user can learn about their blood circulation status.

[0141] Next, the following experiment will be described: When inferring the blood circulation status, a situation where the blood circulation status actually changes is deliberately set, and the measurement by the electronic device 1 of the present embodiment is compared with the measurement by a two-dimensional laser blood flowmeter of the prior art.

[0142] Refer to Figure 22 , and the situation of the change in the blood circulation status of this experiment will be described. In Figure 22 , in the upper frame 301, it shows the state where the table 311 is arranged so that the height of the hand of the subject U is lower than the heart and the subject U is sitting on the chair 312. In contrast, in Figure 22 , in the lower frame 302, it shows the state where the stage 313 is arranged on the table 311, the hand of the subject U is placed on the stage 313, and the subject U is sitting on the chair 312 so that the height of the hand is higher than the heart. And the height difference between the lower position of the hand (the state in the frame 301) and the higher position (the state in the frame 302) is set to 30 cm.

[0143] First, the comparative example will be described. Figure 23 is an image when the height of the hand is low measured by the two-dimensional laser blood flowmeter of the comparative example, Figure 24 is an image when the height of the hand is high. In Figure 23 and Figure 24 , the rectangular frame is the measurement part (ROI; Region Of Interest). The blood flow value measured by the two-dimensional laser blood flowmeter is 18.56 (ml / min / 100g) when the hand height is low and 36.67 (ml / min / 100g) when the hand height is high. If the change rate is calculated based on this value, it is 36.67 / 18.56 = 1.98.

[0144] Next, the present embodiment will be described. Figure 25 is a graph showing the time change of the converted luminance when the height of the hand is low measured by the electronic device 1 according to an embodiment of the present invention, Figure 26 is a graph showing the time change of the converted luminance when the hand height is high. Figure 25 and Figure 26 are the pulse wave information obtained by the electronic device 1 measuring the measurement part of the palm. If Figure 25 and Figure 26 are compared, it can be seen that the baseline is higher when the hand height is low.

[0145] In addition, Figure 27It is a graph that magnifies the waveform of the temporal change in the converted luminance when the hand height measured by the electronic device according to an embodiment of the present invention is low. Figure 28 It is a graph that magnifies the waveform of the temporal change in the converted luminance when the hand height is high. Figure 27 and Figure 28 make the scale widths on the vertical axis consistent. In addition, Figure 27 is a magnified view of Figure 25 The original data (converted luminance) is the same. Figure 28 is also a magnified view of Figure 26 The original data (converted luminance) is the same. If Figure 27 and Figure 28 are compared, it can be seen that the pulse wave amplitude is small when the hand height is low and the pulse wave amplitude is large when the hand height is high.

[0146] Figure 27 The average value of the pulse wave amplitude when the hand is low is 0.22, Figure 28 The average value of the pulse wave amplitude when the hand is high is 0.44. Therefore, the pulse wave amplitude change rate is 0.44 / 0.22 = 2.00, which becomes a value very close to the change rate of 1.98 derived from the measurement results of the two-dimensional laser blood flowmeter. According to the experimental results, it shows that the change in the pulse wave amplitude in the pulse wave information, that is, the change in the intensity of the pulsation, means the change in blood flow. That is, as Figure 18 shown, the increase or decrease in the pulsation change rate can infer the increase or decrease in blood flow.

[0147] In addition, in the two-dimensional laser blood flowmeter of the comparative example, since it is difficult to measure the average blood volume such as the baseline, it is impossible to capture the blood circulation states such as the congestion state and the hyperemia state. In contrast, in the electronic device 1 of the present embodiment, as Figures 12 to 15 the case described in shows, the blood circulation state was verified when significantly swollen and the hyperemia state was measured. In addition, as Figure 22 shown, it was also verified that if the hand height was changed to intentionally accumulate blood in the hand, that is, a state close to congestion was measured, the baseline rose and the pulse wave amplitude decreased. Based on these verification results, it can be said that it shows that various states related to blood flow as shown in Figure 18 can be correctly inferred.

[0148] The effects of the electronic device 1 of the present embodiment will be described. The electronic device 1 includes an image processing unit 111, a data processing unit 114, and a determination processing unit 115. The image processing unit 111 obtains first pulse wave information (converted brightness) representing a pulse wave from a first image obtained by photographing at least a part of the body, and obtains second pulse wave information (converted brightness) representing a pulse wave from a second image obtained by photographing a part of the body or a part corresponding to the part of the body. The data processing unit 114 obtains, from the first pulse wave information and the second pulse wave information, respectively, a baseline which is an average value of the pulse wave within a preset time and a pulse wave amplitude which is an average amplitude of the pulse wave within a preset time, and derives a baseline change rate (baseline change index) representing a change in the baseline in the first pulse wave information and the second pulse wave information and a pulse wave amplitude change rate (pulse wave amplitude change index) representing a change in the pulse wave amplitude in the first pulse wave information and the second pulse wave information. The determination processing unit 115 determines the blood circulation state based on the relationship between the baseline change rate and the pulse wave amplitude change rate.

[0149] Thus, it is possible to determine the blood circulation state based on the change in blood flow generated during the period from photographing the first image to photographing the second image. By deriving the change rates of the baseline and the pulse wave amplitude of the pulse wave extracted from the image, it is possible to not only determine the increase or decrease of blood flow, but also determine the state related to blood circulation such as congestion and hyperemia. In addition, instead of obtaining the absolute value of blood flow, a relative change is derived, so that a dedicated device such as a laser is not required, and even a general-purpose camera can determine the blood circulation state, and the system can be implemented at low cost. In addition, since it is not necessary to use a laser that requires attention in the process as in the prior art, a dedicated operator is not required.

[0150] In addition, the determination processing unit 115 of the present embodiment derives a baseline change rate (BL2 / BL1) by dividing the baseline (BL2) obtained from the second pulse wave information by the baseline (BL1) obtained from the first pulse wave information, and derives a pulse wave amplitude change rate (PA2 / PA1) by dividing the pulse wave amplitude PA2 obtained from the second pulse wave information by the pulse wave amplitude (PA2) obtained from the first pulse wave information.

[0151] Thus, if a numerical range is preset as a range for determining the blood circulation state and the baseline change rate (BL2 / BL1) and the pulse wave amplitude change rate (PA2 / PA1) are derived, the blood circulation state can be determined by a simple process of determining whether or not it falls within the numerical range.

[0152] In addition, the determination processing unit 115 of the present embodiment determines that blood flow increases when the baseline change rate and the pulse wave amplitude change rate indicate that the change in the baseline is small and the pulse wave amplitude shows an increasing trend, and determines that blood flow decreases when the change in the baseline is small and the pulse wave amplitude shows a decreasing trend. Thus, it is possible to correctly determine whether the trend is an increase or a decrease in blood flow through a simple process.

[0153] In addition, the determination processing unit 115 of the present embodiment determines that congestion is improved when the baseline change rate and the pulse wave amplitude change rate indicate that the baseline decreases while the pulse wave amplitude increases, and determines that there is a tendency for congestion when the baseline increases while the pulse wave amplitude decreases. Thus, it is possible to correctly determine whether the patient is in a state of congestion through a simple process.

[0154] In addition, the determination processing unit 115 of the present embodiment determines that blood circulation is improved when the baseline change rate and the pulse wave amplitude change rate indicate that the baseline increases and the pulse wave amplitude also increases, and it is determined that there is poor blood circulation based on the first pulse wave information; and determines that there is a tendency for poor blood circulation when the baseline decreases and the pulse wave amplitude also decreases, and it is determined that the state is normal based on the first pulse wave information. In addition, the determination processing unit 115 determines that congestion is improved when the baseline decreases and the pulse wave amplitude also decreases, and it is determined that there is a tendency for congestion based on the first pulse wave information; and determines that there is a tendency for congestion when the baseline increases and the pulse wave amplitude also increases, and it is determined that the state is normal based on the first pulse wave information. Thus, it is possible to correctly determine blood circulation states such as poor blood circulation, improvement of poor blood circulation, and tendency for congestion through a simple process.

[0155] In addition, the electronic device 1 of the present embodiment further includes: a display processing unit 112 that generates an image for displaying the measurement result determined by the determination processing unit 115. Thus, since the image including the measurement result is displayed on the output unit 18, the user can easily grasp the measurement result.

[0156] In addition, the display processing unit 112 generates, as a measurement result, an image in which the baseline change rate and the pulse wave amplitude change rate derived by the data processing unit 114 are plotted in a graph in which the level of the baseline change rate is set as either the vertical axis or the horizontal axis, the level of the pulse wave amplitude change rate is set as the other of the vertical axis or the horizontal axis, and the graph represents the blood circulation state inferred for each region. Thus, the user can intuitively determine the blood circulation state. In addition, by using the graph, the user can visually grasp the level of the determined blood circulation state.

[0157] [Modification Example]

[0158] The present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within the scope of achieving the object of the present invention are included in the present invention. For example, the above-described embodiments can be modified into the following modified examples.

[0159] In the above embodiment, the baseline change rate is described as an example of the baseline change index, but the process of subtracting 1 can also be omitted. In addition, the result of subtracting the baseline of the pulse wave information in the first measurement from the baseline of the pulse wave information in the second measurement can also be used as the baseline change index. Similarly, the pulse wave amplitude change rate is described as an example of the pulse wave amplitude change index, but the result of subtracting the pulse wave amplitude of the pulse wave information in the first measurement from the pulse wave amplitude of the pulse wave information in the second measurement can also be used as the pulse wave amplitude change index. In this way, the method of deriving the baseline change index and the pulse wave amplitude change index can be appropriately changed.

[0160] In the above embodiment, a structure in which comparison processing is performed using the converted luminance value obtained by converting the detected luminance is described, but it is not limited to this structure. The converted luminance value is one way of representing the luminance level, and the conversion process can also be omitted from the above embodiment, and the detected luminance value can be used for comparison processing without performing the conversion process.

[0161] For example, in the above embodiment, it is assumed that the electronic device 1 cooperates with each server included in the server group 3, but the functions of each server can also be added to the electronic device 1, and all the processing can be performed only by the electronic device 1.

[0162] The above series of processes can be executed by hardware or by software. The above functional structure is merely an example and is not particularly limited. That is, the electronic device 1 only needs to have a function capable of executing the above series of processes as a whole, and it is not particularly limited which functional modules are used to achieve this function Figure 6 for example.

[0163] In addition, a functional module can be constituted by a single hardware, by a single software, or by a combination thereof. The functional structure in the present embodiment is realized by a processor that executes arithmetic processing. Among the processors that can be used in the present embodiment, in addition to being constituted by various processing devices such as a single processor, a multi-processor, and a multi-core processor, it also includes devices in which these various processing devices are combined with processing circuits such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field-Programmable Gate Array).

[0164] In the case where a series of processes are executed by software, the program constituting the software is installed on a computer or the like from a network or a recording medium.

[0165] The computer may be a computer incorporating dedicated hardware. In addition, the computer may be a computer capable of executing various functions through various programs, such as a general-purpose personal computer.

[0166] In order to provide a program to a user, the recording medium containing such a program may be constituted not only by a removable medium 100 arranged independently of the device main body, but also by a recording medium or the like provided to the user in a state pre-assembled in the device main body. The removable medium 100 includes, for example, a magnetic disk (including a floppy disk), an optical disk, or an optical magnetic disk. The optical disk includes, for example, a CD-ROM (Compact Disk - Read Only Memory), a DVD, a Blu-ray (registered trademark) Disc (Blu-ray Disc), etc. The optical magnetic disk includes an MD (Mini-Disk), etc. In addition, the recording medium provided to the user in a state pre-assembled to the device main body includes, for example, a ROM 12 recording a program, and a hard disk or the like included in the storage unit 19.

[0167] In addition, in this specification, the steps of describing the program recorded in the recording medium certainly include the processes performed in time series along its sequence, and also include the processes performed in parallel or independently without necessarily being performed in time series. In addition, in this specification, the term "system" means an overall device including a plurality of devices, a plurality of units, etc.

[0168] As described above, several embodiments of the present invention have been described, but these embodiments are merely examples and do not limit the technical scope of the present invention. The present invention can achieve various other embodiments, and furthermore, various changes such as omission and replacement can be made without departing from the gist of the present invention. These embodiments and their modifications are included in the scope and gist of the invention described in this specification, and are included in the invention described in the claims and its equivalent scope.

[0169]

Explanation of Symbols

[0170] 1 Electronic device

[0171] 6 Imaging unit

[0172] 111 Image processing unit

[0173] 112 Display processing unit

[0174] 114 Data processing unit

[0175] 115 Judgment processing unit.

Claims

1. An electronic device, comprising: an image processing unit that obtains first pulse wave information representing a pulse wave from a first image obtained by photographing a part of a subject's body during a first period, and obtains second pulse wave information representing a pulse wave from a second image obtained by photographing the part of the subject's body during a period after the first period, i.e., a second period; a data processing unit that respectively obtains a baseline representing an average value of pulse wave information within a specified time and a pulse wave amplitude from the first pulse wave information and the second pulse wave information, and derives a baseline change index representing a change rate of the baseline in the first pulse wave information and the second pulse wave information, and a pulse wave amplitude change index representing a change rate of the pulse wave amplitude in the first pulse wave information and the second pulse wave information; and a determination processing unit that determines a blood circulation state based on the relationship between the baseline change index and the pulse wave amplitude change index.

2. The electronic device according to claim 1, wherein the determination processing unit derives the baseline change index as a baseline change rate by dividing the baseline obtained from the second pulse wave information by the baseline obtained from the first pulse wave information, and the determination processing unit derives the pulse wave amplitude change index as a pulse wave amplitude change rate by dividing the pulse wave amplitude obtained from the second pulse wave information by the pulse wave amplitude obtained from the first pulse wave information.

3. The electronic device according to claim 2, wherein the determination processing unit, based on the baseline change rate and the pulse wave amplitude change rate, determines that blood flow increases when it indicates a trend of little change in the baseline and an increase in the pulse wave amplitude, and determines that blood flow decreases when it indicates a trend of little change in the baseline and a decrease in the pulse wave amplitude.

4. The electronic device according to claim 2 or 3, wherein the determination processing unit, based on the baseline change rate and the pulse wave amplitude change rate, determines that congestion is improved when it indicates a trend of a decrease in the baseline and an increase in the pulse wave amplitude, and determines that there is a tendency of congestion when it indicates a trend of an increase in the baseline and a decrease in the pulse wave amplitude.

5. The electronic device according to claim 2 or 3, wherein the determination processing unit based on the baseline change rate and the pulse wave amplitude change rate, determines that blood circulation is improved when it indicates a trend of an increase in the baseline and an increase in the pulse wave amplitude and is determined to have poor blood circulation based on the first pulse wave information, determines that there is poor blood circulation when it indicates a trend of a decrease in the baseline and a decrease in the pulse wave amplitude and is determined to be in a normal state based on the first pulse wave information, determines that congestion is improved when it indicates a trend of a decrease in the baseline and a decrease in the pulse wave amplitude and is determined to have a tendency of congestion based on the first pulse wave information, and determines that there is a tendency of congestion when it indicates a trend of an increase in the baseline and an increase in the pulse wave amplitude and is determined to be in a normal state based on the first pulse wave information.

6. The electronic device according to any one of claims 1 to 3, wherein, the electronic device further includes: a display processing unit that generates an image for displaying the measurement result determined by the determination processing unit.

7. The electronic device according to claim 6, wherein, the display processing unit generates, as the measurement result, an image in which the level of the baseline change index is set as either the vertical axis or the horizontal axis, the level of the pulse wave amplitude change index is set as the other of the vertical axis or the horizontal axis, and a graph representing the inferred blood circulation state for each region, and plots the baseline change index and the pulse wave amplitude change index derived by the data processing unit.

8. A recording medium storing a program that causes an electronic device for measuring blood flow based on an image obtained by photographing a subject's body to implement the following functions: an image processing function that acquires first pulse wave information representing a pulse wave from a first image obtained by photographing a part of the subject's body during a first period, and acquires second pulse wave information representing a pulse wave from a second image obtained by photographing a part of the subject's body during a second period after the first period; a data processing function that respectively acquires a baseline and a pulse wave amplitude representing an average value of pulse wave information within a predetermined time from the first pulse wave information and the second pulse wave information, and derives a baseline change index representing a change rate of the baseline in the first pulse wave information and the second pulse wave information, and a pulse wave amplitude change index representing a change rate of the pulse wave amplitude in the first pulse wave information and the second pulse wave information; and a determination processing function that determines a blood circulation state based on a relationship between the baseline change index and the pulse wave amplitude change index.

9. A control method for an electronic device that measures blood flow based on an image obtained by photographing a subject's body, the control method of the electronic device including: an image processing step of acquiring first pulse wave information representing a pulse wave from a first image obtained by photographing a part of the subject's body during a first period, and acquiring second pulse wave information representing a pulse wave from a second image obtained by photographing a part of the subject's body during a second period after the first period; a data processing step of respectively acquiring a baseline and a pulse wave amplitude representing an average value of pulse wave information within a predetermined time from the first pulse wave information and the second pulse wave information, and deriving a baseline change index representing a change rate of the baseline in the first pulse wave information and the second pulse wave information, and a pulse wave amplitude change index representing a change rate of the pulse wave amplitude in the first pulse wave information and the second pulse wave information; and a determination processing step of determining a blood circulation state based on a relationship between the baseline change index and the pulse wave amplitude change index.

Images