Patent Description:
In order to detect orthostatic hypotension, it is necessary to measure a change in blood pressure at a time of a shift in posture, and blood pressure is conventionally measured by a contact type device (see Patent Literature <NUM> (<CIT>)). In addition, there is a continuous sphygmomanometer that is of a contact type and can measure a change in blood pressure chronologically.

<CIT>, <CIT>, <CIT>, and <CIT> each disclose a facial change information acquirer that is configured to acquire facial change information indicating a chronological change in face data which is obtained from a face of the subject and related to a complexion of the subject, and that includes a color space processor configured to perform color separation processing of separating the facial change information into three color components of an red component, a green component, and a blue component.

<CIT> discloses a sensor device configured to detect a patient's pulse by using a photoplethysmography sensor, and reduce noise components of the measured PPG signal based on motion signal indicating a motion of the patient and obtained by using a motion sensor.

Measuring a change in blood pressure at the time of a shift in posture requires a complicated measurement task. Thus, the measurement task is desired to be simple. In addition, because of the high price of the continuous sphygmomanometer, the measurement of the change in blood pressure is substituted by measurement of a heart rate change. As described above, it is desired to easily determine a physiological state of body such as a blood pressure.

A determination system according to claim <NUM> is disclosed.

The determination system may further include a first photographing unit that photographs a part of the body surface without contacting the subject. The body surface data is first photographed image data photographed by the first photographing unit.

The determination system may further include a second photographing unit that photographs the subject without contacting the subject. The motion detector detects the motion of the subject based on second photographed image data photographed by the second photographing unit.

The motion detector may be configured to detect the standing motion of the subject based on the face data.

<FIG> illustrates a determination system <NUM> according to a first embodiment.

The determination system <NUM> determines a physiological state of mind or body by using image data (body surface data) obtained from a part of a body surface of a subject to be determined. The determination system <NUM> includes a control unit <NUM>, a face recording camera <NUM>, and a face position recording camera <NUM>. The control unit <NUM> includes a facial change information acquirer <NUM>, a motion detector <NUM>, and a physiological state determiner <NUM>.

Note that the control unit <NUM> can be implemented by a computer including a control calculator and a storage (neither illustrated). Examples of the control calculator include a processor such as a CPU or a GPU. The control calculator reads a control program stored in the storage and performs each processing in accordance with the control program. The control calculator can write a calculation result to the storage, and read information stored in the storage, in accordance with the control program.

First photographed image data is input from the face recording camera <NUM> to the facial change information acquirer <NUM>. Second photographed image data is input from the face position recording camera <NUM> to the motion detector <NUM>.

The facial change information acquirer <NUM> is a body surface change information acquirer that acquires facial change information indicating a chronological change in face data of the subject. Specifically, the facial change information acquirer <NUM> records chronologically the first photographed image data, which represent a photographed image of the subject photographed by the face recording camera <NUM>, as face data that is body surface data related to a complexion of the subject, and acquires facial change information as body surface change information indicating a chronological change in the face data.

The facial change information acquirer <NUM> may use, as the face data, image data of a periphery of paranasal sinuses and/or a forehead of the subject included in the first photographed image data.

The facial change information acquirer <NUM> includes a color space processor <NUM>. The color space processor <NUM> performs color separation processing of separating the facial change information into three color components, namely, an R component, a G component, and a B component.

The facial change information acquirer <NUM> acquires a component representing a characteristic of the physiological state and/or a conversion value, from color components included in the facial change information having been subjected to the color separation processing by the color space processor <NUM>.

The motion detector <NUM> detects a motion of the subject based on a height and a motion of a feature point of a predetermined region included in the second photographed image data. The motion of the subject refers to a height change of the head when the motion causes no change in a relative height between the heart and the head (for example, a motion from a sitting position to a standing position). The motion of the subject refers to a height change of the heart when the motion causes a change in the relative height between the heart and the head (for example, in a head-up tilt test of a head fixed type).

For example, when the subject stands up from a state of sitting on a chair, the feature point of the face of the subject included in the second photographed image data moves and rests still. As the height of the head of the subject changes, it is detected that the subject stands up.

The physiological state determiner <NUM> determines the physiological state of mind or body of the subject based on the face data acquired upon detecting the motion of the subject by the motion detector <NUM>. Specifically, the physiological state determiner <NUM> determines the physiological state of mind or body of the subject based on the component representing the characteristic of the physiological state acquired by the facial change information acquirer <NUM> and/or the conversion value. The physiological state includes a decrease or an increase in a blood pressure, a pulse, a heart rate, and an autonomic nervous system activity of the subject.

The face recording camera <NUM> is a first photographing unit that photographs the subject without contacting (in non-contact with) the subject. The face recording camera <NUM> inputs the photographed first photographed image data to the facial change information acquirer <NUM>.

The face position recording camera <NUM> is a second photographing unit that photographs the subject without contacting (in non-contact with) the subject. The face position recording camera <NUM> inputs the photographed first photographed image data to the facial change information acquirer <NUM>.

<FIG> illustrates an example of a motion of the subject to be determined by the determination system <NUM>. Hereinafter, determination processing performed by the determination system <NUM> will be described by exemplifying a case where the subject performs the motion illustrated in <FIG>. First, the subject sits on a chair and rests for <NUM> seconds (sitting position). Next, when a measurer instructs the subject to stand up, the subject stands up in about <NUM> seconds (standing motion). Next, the subject rests while standing for <NUM> seconds (standing position).

<FIG> illustrates a flow of processing of the control unit <NUM>.

Upon start of processing by the control unit <NUM>, the subject sits on a chair placed in front of the face recording camera <NUM> and the face position recording camera <NUM> (sitting position). When the control unit <NUM> starts the processing, the first photographed image data of the face of the subject is input from the face recording camera <NUM> to the facial change information acquirer <NUM>. The second photographed image data of the subject is input from the face position recording camera <NUM> to the motion detector <NUM>.

When the subject stands up from the state of sitting on the chair (standing motion), the motion detector <NUM> detects the motion of the subject based on the second photographed image data input from the face position recording camera <NUM> to the motion detector <NUM> (step S111).

Next, based on the first photographed image data input from the face recording camera <NUM> to the facial change information acquirer <NUM>, the facial change information acquirer <NUM> acquires facial change information indicating a chronological change in the face data of the subject (step S112). At this time, the facial change information acquirer <NUM> uses, for example, image data of the periphery of the paranasal sinuses and/or the forehead of the subject included in the first photographed image data as the face data. The color space processor <NUM> of the facial change information acquirer <NUM> performs the color separation processing of separating the facial change information into three color components such as the R component (red component), the G component (green component), and the B component (blue component).

Next, the facial change information acquirer <NUM> analyzes the acquired facial change information (step S113). The facial change information acquirer <NUM> acquires the G component representing a characteristic of the physiological state and/or a conversion value such as an erythema index or a hemoglobin component, from the color components included in the facial change information having been subjected to the color separation processing by the color space processor <NUM>.

The erythema index is an index representing a degree of "redness" of the skin using absorbance of the skin, and is, for example, an index obtained from RGB information by a calculation formula shown in the following Formula <NUM>.

The hemoglobin component is a value linked to an amount of hemoglobin estimated from the RGB information of the skin when it is assumed that the skin is of a two-layer model of a melanin layer and a hemoglobin layer.

Next, the physiological state determiner <NUM> determines the physiological state of the subject based on the face data acquired upon detecting the motion of the subject (step S114). The physiological state determiner <NUM> can determine the physiological state of mind or body of the subject such as a decrease or an increase in the blood pressure, the pulse, the heart rate, and the autonomic nervous system activity of the subject based on the component representing the characteristic of the physiological state acquired, from the face data, by the facial change information acquirer <NUM> and/or the conversion value before and after the motion of the subject.

Next, the control unit <NUM> outputs a determination result of the physiological state of mind or body of the subject by the physiological state determiner <NUM> to an output unit (not illustrated) (step S115), and ends the processing.

(<NUM>-<NUM>)
The control unit <NUM> included in the determination system <NUM> according to the present embodiment includes the facial change information acquirer <NUM>, the motion detector <NUM>, and the physiological state determiner <NUM>. The facial change information acquirer <NUM> acquires the facial change information indicating a chronological change in the face data of the subject. The motion detector <NUM> detects the motion of the subject. The physiological state determiner <NUM> determines the physiological state of mind or body of the subject based on the face data acquired upon detecting the motion of the subject.

The determination system <NUM> can easily determine the physiological state of mind or body of the subject. In addition, in this determination system, for example, it is possible to determine the physiological state of mind or body of the subject at low cost without using a device such as an expensive continuous sphygmomanometer.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the facial change information acquirer <NUM> acquires, as face data, image data of the periphery of the paranasal sinuses and/or the forehead of the subject.

In the determination system <NUM>, by acquiring data of a region of the face where a particularly large blood vessel exists, it is possible to easily determine the physiological state of mind or body of the subject.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the face data is data related to the complexion of the subject.

In the determination system <NUM>, since the complexion of the subject is known, it is possible to easily determine the physiological state of mind or body of the subject.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the facial change information acquirer <NUM> includes the color space processor <NUM> that performs the color separation processing of separating the facial change information of the subject into three color components, namely, the R component, the G component, and the B component.

The determination system <NUM> can determine the physiological state of mind or body of the subject.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the facial change information acquirer <NUM> acquires the G component and/or the conversion value of the erythema index, the hemoglobin component, or the like from the color component included in the facial change information subjected to the color separation processing.

The determination system <NUM> can easily determine the physiological state of mind or body of the subject by using the color component of the photographed image data in which the change in the complexion of the subject is easily detected.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the motion of the subject is a motion including a height change of the head or the like of the subject.

In the determination system <NUM>, the movement of the subject is easily detected, and then the physiological state of mind or body of the subject can be easily determined.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the face recording camera <NUM> photographs in non-contact with the subject.

The determination system <NUM> can reduce a burden on the measurer and the subject.

(<NUM>-<NUM>)
In the determination system <NUM> according to the present embodiment, the physiological state includes a decrease or an increase in the blood pressure, the pulse, the heart rate, and the autonomic nervous system activity of the subject.

The determination system <NUM> can determine various physiological states.

In the determination system <NUM>, the first photographed image data and the second photographed image data are obtained using the two cameras of the face recording camera <NUM> and the face position recording camera <NUM>. However, the first photographed image data and the second photographed image data may be obtained using one camera.

In the present embodiment, the face recording camera <NUM> may be an infrared camera. This enables the first photographed image data to be obtained regardless of brightness of external environment. In this case, since the data from the infrared camera has one wavelength band, the processing proceeds to step S113 without performing step S112. Note that, there are a plurality of wavelength bands in a case where the infrared camera is a multi-wavelength camera. Thus, in step S112, the color space processor <NUM> performs decomposition processing of decomposing the facial change information into one or more predetermined wavelength band components included in an infrared wavelength band.

Then, in step S113, the facial change information acquirer <NUM> acquires a component representing the characteristic of the physiological state from the predetermined wavelength band components that are generated by the decomposition processing and included in the face change information.

Furthermore, in step S114, it is possible to determine the physiological state of mind or body of the subject, such as a decrease or an increase in the blood pressure, the pulse, the heart rate, and the autonomic nervous system activity of the subject, based on the component representing the characteristic of the physiological state acquired, from the face data, by the facial change information acquirer <NUM> before and after the motion of the subject.

The determination system <NUM> may further include a guide unit capable of keeping a constant distance between the subject and at least one of the face recording camera <NUM> and the face position recording camera <NUM> by contacting the subject and at least one of the face recording camera <NUM> and the face position recording camera <NUM>. This allows photographing of the subject at a constant distance, and thus improves determination accuracy of the determination system <NUM>.

Next, a determination system <NUM> according to a second embodiment will be described focusing on a difference from the determination system <NUM>. <FIG> is a diagram of the determination system <NUM>. The difference between the determination system <NUM> and the determination system <NUM> is that the determination system <NUM> uses the image data of a fingertip surface of the subject to determine the physiological state of mind or body. Note that the same reference signs are given to the corresponding configurations in the respective embodiments, and the description thereof will be omitted.

The determination system <NUM> includes a control unit <NUM> and a fingertip recording camera <NUM>. The control unit <NUM> includes a fingertip change information acquirer <NUM>, a motion detector <NUM>, and the physiological state determiner <NUM>.

The fingertip recording camera <NUM> photographs an image of a surface of the fingertip of the subject and inputs the photographed image to the fingertip change information acquirer <NUM> and the motion detector <NUM> as third photographed image data.

The fingertip change information acquirer <NUM> is a body surface change information acquirer that acquires fingertip change information indicating a chronological change in fingertip data of the subject. Specifically, the fingertip change information acquirer <NUM> records chronologically the third photographed image data photographed by the fingertip recording camera <NUM> as fingertip data that is body surface data related to a color of the fingertip surface of the subject, and acquires fingertip change information that is fingertip change information indicating the chronological change of the fingertip data.

Similarly to the facial change information acquirer <NUM>, the fingertip change information acquirer <NUM> includes the color space processor <NUM>. The color space processor <NUM> performs color separation processing of separating the fingertip change information into three color components, namely, the R component, the G component, and the B component.

The fingertip change information acquirer <NUM> acquires a component representing the characteristic of the physiological state and/or a conversion value, from color components included in the fingertip change information having been subjected to the color separation processing by the color space processor <NUM>.

The motion detector <NUM> detects the motion of the subject based on the third photographed image data. Specifically, the motion detector <NUM> detects whether a predetermined pattern indicating the motion of the subject is included in the color component representing the characteristic of the physiological state and/or the conversion value acquired by the fingertip change information acquirer <NUM>, and determines that there is a motion of the subject upon detection of the predetermined pattern.

Here, as the predetermined pattern indicating the motion of the subject, the motion detector <NUM> can use, for example, a pattern in which the R component decreases by a predetermined amount or more within a predetermined time. This pattern indicates occurrence of a phenomenon in which a blood flow of the fingertip physically decreases before the autonomic nerve acts due to the standing motion. Detection of this pattern from the R component allows the motion detector <NUM> to determine that there is a motion (standing motion) of the subject.

The physiological state determiner <NUM> determines the physiological state of mind or body of the subject based on the fingertip data acquired upon detecting the motion of the subject by the motion detector <NUM>. Specifically, the physiological state determiner <NUM> determines the physiological state of mind or body of the subject based on the component representing the characteristic of the physiological state acquired by the fingertip change information acquirer <NUM> and/or the conversion value. The physiological state includes a decrease or an increase in a blood pressure, a pulse, a heart rate, and an autonomic nervous system activity of the subject.

The fingertip recording camera <NUM> is a third photographing unit that photographs the fingertip surface of the subject. The fingertip recording camera <NUM> includes a sensor <NUM>, lens <NUM>, and an illumination <NUM>.

The sensor <NUM> acquires an image of the fingertip surface via the lens <NUM>. The fingertip recording camera <NUM> inputs the image acquired by the sensor <NUM> to the fingertip change information acquirer <NUM> and the motion detector <NUM>. The illumination <NUM> irradiates the finger of the subject with light when an image is photographed. The lens <NUM> and the illumination <NUM> are disposed adjacent to each other so as to be touched by the fingertip simultaneously.

<FIG> is a schematic diagram illustrating how the fingertip surface of the subject is photographed by the fingertip recording camera <NUM>. When the fingertip recording camera <NUM> acquires the third photographed image data, the subject touches the lens <NUM> and the illumination <NUM> with the fingertip surface as illustrated in <FIG>. Accordingly, the light emitted from the illumination <NUM> is transmitted through the fingertip surface and then acquired by the sensor <NUM> via the lens <NUM>.

A digital camera with a flash (illumination) attached to a smartphone may be used as the fingertip recording camera <NUM>. In this case, the flash is used as the illumination <NUM>.

Processing of the control unit <NUM> will be described by exemplifying the motion of the subject illustrated in <FIG>.

<FIG> illustrates a flow of the processing of the control unit <NUM>.

Upon start of processing by the control unit <NUM>, the subject sits on a chair with the fingertip surface in contact with the fingertip recording camera <NUM> (sitting position). When the control unit <NUM> starts the processing, the third photographed image data is input from the fingertip recording camera <NUM> to the fingertip change information acquirer <NUM> and the motion detector <NUM>.

When the subject stands up from the chair while the fingertip surface is still in contact with the fingertip recording camera <NUM> (standing motion), the motion detector <NUM> detects the motion of the subject based on the third photographed image data input from the fingertip recording camera <NUM> to the motion detector <NUM> (step S211).

Next, based on the third photographed image data input from the fingertip recording camera <NUM> to the fingertip change information acquirer <NUM>, the fingertip change information acquirer <NUM> acquires the fingertip change information indicating the chronological change in the fingertip data of the subject (step S212). The color space processor <NUM> of the fingertip change information acquirer <NUM> performs the color separation processing of separating the fingertip change information into three color components such as the R component, the G component, and the B component.

Next, the fingertip change information acquirer <NUM> analyzes the acquired fingertip change information (step S213). The fingertip change information acquirer <NUM> acquires the R component representing a characteristic of the physiological state and/or a conversion value such as an erythema index or a hemoglobin component, from the color components included in the fingertip change information having been subjected to the color separation processing by the color space processor <NUM>.

Next, the physiological state determiner <NUM> determines the physiological state of the subject based on the fingertip data acquired upon detecting the motion of the subject (step S214). Specifically, the physiological state determiner <NUM> can determine the physiological state of mind or body of the subject such as a decrease or increase in the blood pressure, the pulse, the heart rate, and the autonomic nervous system activity of the subject based on the component representing the characteristic of the physiological state acquired from the fingertip data by the fingertip change information acquirer <NUM> and/or the conversion value before and after the motion of the subject.

Next, the control unit <NUM> outputs a determination result of the physiological state of mind or body of the subject by the physiological state determiner <NUM> to an output unit (not illustrated) (step S215), and ends the processing.

(<NUM>-<NUM>)
In the determination system <NUM>, the body surface data is data obtained from the surface of the fingertip of the subject.

Therefore, the determination system <NUM> can obtain the determination result of the physiological state of mind or body by a simple operation.

(<NUM>-<NUM>)
In the determination system <NUM>, the fingertip data can be acquired by the fingertip recording camera <NUM> being in contact with the fingertip.

Therefore, in the determination system <NUM>, an influence of ambient light and the motion of the subject or the like can be suppressed, and the fingertip data can be obtained by a simple operation.

(<NUM>-<NUM>)
In the determination system <NUM>, the motion detector <NUM> detects the motion of the subject based on the fingertip data.

The determination system <NUM>, not requiring a camera for recording the position of the subject, simplifies a structure and suppresses a manufacturing cost.

In the determination system <NUM>, in step S213, the color component acquired from the fingertip change information by the fingertip change information acquirer <NUM> is the R component. This is because the R component essentially transmits well through a living body and is easily detected by the sensor <NUM> without a sufficient light amount of the illumination <NUM>.

Therefore, when the sensor <NUM> can detect without using the R component, such as when a sufficient light amount can be secured, the color component acquired from the fingertip change information by the fingertip change information acquirer <NUM> may be, for example, the G component or the B component other than the R component.

The fingertip recording camera <NUM> may be, for example, an infrared camera similarly to the face recording camera <NUM>.

The subject performed the motion illustrated in <FIG>, and the physiological state was determined by the determination system <NUM> according to the first embodiment. In addition, for evaluation of the determination system <NUM>, the blood pressure and the heart rate were simultaneously measured by the continuous sphygmomanometer.

In this test, BP Monitor Ohmeda manufactured by Finapres Medical Systems was used as a continuous sphygmomanometer as a measuring instrument. As a recording apparatus, a digital oscilloscope DL <NUM> manufactured by Yokogawa Electric Corporation was used. As the face recording camera <NUM>, a camera A1H manufactured by Panasonic Corporation was used. As the face position recording camera <NUM>, a camera WAT-01U2 manufactured by Watec Co. The continuous sphygmomanometer is a contact type.

The continuous sphygmomanometer is used in this test, but is not a constituent element of the whole system in <FIG>.

<FIG> illustrate an example of a measurement result of this test.

The subject is a healthy male person at age of <NUM>.

<FIG> illustrates a result of measuring the blood pressure of the subject with the continuous sphygmomanometer. A vertical axis represents blood pressure (mmHg), and a horizontal axis represents time (seconds).

<FIG> illustrates a result of estimating the heart rate of the subject from the pulse rate. A vertical axis represents the heart rate (stroke/minute), and a horizontal axis represents time (second).

<FIG> illustrates a change in the complexion of the subject obtained by the control unit <NUM>. A vertical axis represents the green component obtained by performing the color separation processing on the facial change information obtained from the first photographed image data input from the face recording camera <NUM>. A vertical axis represents the green component included in the face data, and a horizontal axis represents time (second). The green component is an average of pixel values (gradation) of the green component in a plurality of pixels included in a predetermined range of the first photographed image data.

<FIG> illustrates a change in a height of the face of the subject obtained by the determination system <NUM>. A vertical axis indicates a height coordinate in the second photographed image data with <NUM> seconds as an origin of the face in the second photographed image data photographed by the face position recording camera <NUM>. A horizontal axis represents time (second).

As illustrated in <FIG>, sitting time is <NUM> seconds, and the height of the face is <NUM>. Next, upon start of the measurement, since the subject is sitting on a chair and rests from <NUM> seconds to <NUM> seconds, the height of the face remains <NUM>. When the subject performs the standing motion <NUM> seconds after the measurement is started, the height of the face becomes about <NUM> pixels. Thereafter, the subject is at rest while standing for <NUM> seconds, and thus the height of the face remains about <NUM> pixels from <NUM> seconds to <NUM> seconds.

In <FIG>, vertical lines around <NUM> seconds after the start of the measurement indicate a timing at which the subject stands up from a state of sitting on the chair.

As illustrated in <FIG>, the subject stands up after <NUM> seconds elapse from the start of the measurement, and the blood pressure decreases from <NUM> seconds to <NUM> seconds. Thereafter, the blood pressure increases from <NUM> seconds to <NUM> seconds, and returns to a level of the blood pressure during the sitting position from <NUM> seconds to <NUM> seconds.

As illustrated in <FIG>, the subject stands up after <NUM> seconds elapse from the start of the measurement, and the heart rate increases from <NUM> seconds to <NUM> seconds. Thereafter, the heart rate decreases after <NUM> seconds elapse from the start of measurement, and returns to a level of the heart rate during the sitting position from <NUM> seconds to <NUM> seconds.

As shown in <FIG>, the subject stands up after <NUM> seconds elapse from the start of the measurement, and the green component of the complexion turns into increase from <NUM> seconds to <NUM> seconds. This indicates that when the subject stands up from a state of sitting on the chair, the blood pressure decreases and the complexion becomes blue. Thereafter, the green component of the complexion temporarily decreases and increases again from <NUM> seconds to <NUM> seconds. When <NUM> seconds or more elapse from the start of the measurement, the green component of the complexion returns to a level of the green component during the sitting position from <NUM> seconds to <NUM> seconds.

As described above, the blood pressure, the heart rate, and the complexion change at a timing at which the height of the face of the subject changes.

In this test, it has been confirmed that data on the complexion based on the face data obtained by the face recording camera <NUM> coincides with data obtained by measuring the blood pressure and the heart rate through contact measurement.

As shown in <FIG>, when a healthy person stands up from a state of sitting on the chair, the green component of the complexion increases and the complexion changes, but thereafter, the green component of the complexion immediately decreases and the complexion returns to an original state.

Here, in the detection of orthostatic hypotension, it is necessary to measure a change in blood pressure at a time of a shift in posture. The blood pressure of a healthy person temporarily decreases and returns to the original state in a short time due to a shift in posture. This physiological reaction prevents so-called "dizziness". In addition, the heart rate increases conversely and gradually returns to the original state. On the other hand, since the complexion changes substantially the same as the blood pressure, the determination system <NUM> according to the present embodiment is effective as, for example, non-contact and inexpensive detection of orthostatic hypotension. Specifically, in the determination system <NUM>, the physiological state determiner <NUM> obtains a time from when the green component of the complexion increases due to the standing motion of the subject to when the green component of the complexion returns to the level of the green component during the sitting position based on the facial change information, and compares the obtained time with a predetermined reference time. When the time until the green component of the complexion returns to the level of the green component during the sitting position is longer than the reference time, the physiological state determiner <NUM> can determine that there is a risk of orthostatic hypotension in the subject.

<FIG> illustrate another example of the measurement result of this test.

The subject is a healthy male person at age of <NUM>. The measurement results of the subjects in <FIG> are almost the same as those in <FIG>.

The physiological state was determined by the determination system <NUM> according to the second embodiment. In addition, for evaluation of the determination system <NUM>, the blood pressure was simultaneously measured by the continuous sphygmomanometer.

In the determination of the determination system <NUM>, the subject performs a motion of sitting on a chair and resting for <NUM> seconds (sitting position), and when the measurer instructs to stand up, the subject performs five rounds of motions of standing up and then resting (standing position) for <NUM> seconds. In each interval of the rounds, the subject took a sufficient break.

In the test in Example <NUM>, BP Monitor Ohmeda manufactured by Finapres Medical Systems was used as a continuous sphygmomanometer as a measuring instrument. As a recording apparatus, a digital oscilloscope DL <NUM> manufactured by Yokogawa Electric Corporation was used. As the fingertip recording camera <NUM>, a digital camera attached to iPhone (registered trademark) <NUM> manufactured by Apple Inc. The continuous sphygmomanometer is a contact type.

At a time of photographing, a illumination next to the lens of the fingertip recording camera <NUM> was turned on. For photographing with the fingertip recording camera <NUM>, a camera application installed as standard in the iPhone <NUM> was used. Photographing conditions were <NUM> p and <NUM> fps, and a codec was H. <NUM> (lossless compression). The fingertip recording camera <NUM> was held at a height of the heart by the subject during the determination.

In the determination system <NUM> in Example <NUM>, the erythema index was obtained from the formula shown in Formula <NUM> using the R component, the G component, and the B component.

The continuous sphygmomanometer is used in this test, but is not a constituent element of the determination system <NUM>. <FIG> illustrate measurement results of the first to fifth tests of Example <NUM>.

<FIG> illustrate the blood pressure, R component, G component, B component, and erythema index in order from the top.

The blood pressure is a result of measuring the blood pressure of the subject with the continuous sphygmomanometer, and a vertical axis represents the blood pressure (mmHg) and a horizontal axis represents time (seconds).

The R component, the G component, and the B component are values obtained by the fingertip change information acquirer <NUM> from the fingertip data obtained by the fingertip recording camera <NUM>, and the vertical axis represents each color component and the horizontal axis represents time (seconds). Each color component is an average of pixel values (gradation) of each color component in a plurality of pixels included in a predetermined range of the third photographed image data.

The erythema index is a value obtained by the fingertip change information acquirer <NUM> from the R component, the G component, and the B component, the vertical axis represents the erythema index, and the horizontal axis represents time (seconds).

As illustrated in <FIG>, when the subject stands up after <NUM> seconds elapse from the start of the measurement, the blood pressure decreases from <NUM> seconds to <NUM> seconds. Thereafter, the blood pressure increases between <NUM> seconds and <NUM> seconds, and returns to a level of the blood pressure during the sitting position from <NUM> seconds to <NUM> seconds.

As illustrated in <FIG>, the subject stands up after <NUM> seconds elapse from the start of the measurement, and the R component turns into increase from <NUM> seconds to <NUM> seconds. This indicates that when the subject stands up from a state of sitting on the chair, the blood pressure decreases and the color of the fingertip becomes red. Thereafter, the R component temporarily decreases and increases again from <NUM> seconds to <NUM> seconds. When <NUM> seconds elapse from the start of the measurement, the R component returns to a level of the R component during the sitting position from <NUM> seconds to <NUM> seconds. The same tendency was observed for the erythema index obtained from the R component, the G component, and the B component.

It was confirmed by the test of Example <NUM> that data based on the fingertip data obtained by the fingertip recording camera <NUM> coincides with data obtained by measuring the blood pressure through contact measurement. It has been also confirmed that orthostatic hypotension can be determined by using the determination system <NUM> as well as using the determination system <NUM>.

In the test of Example <NUM>, a detection value of the G component was close to zero except for the second test illustrated in <FIG>. This is considered to be because the G component and the B component other than the R component are hardly transmitted through the living body, and a sufficient amount of light failed to reach the sensor <NUM>.

The embodiments of the present disclosure have been described above. Various modifications to modes and details should be available without departing from the scope of the appended claims.

Claim 1:
A determination system (<NUM>) comprising:
a facial change information acquirer (<NUM>) that is configured to acquire facial change information indicating a chronological change in face data which is obtained from a face of the subject and related to a complexion of the subject, and that includes a color space processor (<NUM>) configured to perform color separation processing of separating the facial change information into three color components of an red component, a green component, and a blue component,
a motion detector (<NUM>) configured to detect a standing up motion of the subject and characterised by
a physiological state determiner (<NUM>) configured to
obtain a time from when the green component of the complexion increases due to the standing up motion of the subject to when the green component of the complexion returns to a level of the green component during a sitting position of the subject based on the facial change information,
compare the obtained time with a predetermined reference time, and
determine that there is a risk of orthostatic hypotension in the subject when the obtained time is longer than the predetermined reference time.