JP2021186063A - Body state monitoring system and bed system - Google Patents

Abstract

To provide a body state monitoring system capable of more accurately detecting a subject's defecation or defecation or urination.SOLUTION: A body state monitoring system for monitoring a subject's body state on a bed comprises: a plurality of load detectors provided at the bed or under legs of the bed to detect a load of the subject; an odor detection unit for detecting an odor on the bed; a sign motion estimation unit for estimating the subject's defecation sign motion on the basis of temporal variations in the detected load of the subject; and an excretion determination unit for determining the presence/absence of defecation by the subject on the basis of a detection result of the odor detection unit and an estimation result of the sign motion estimation unit.SELECTED DRAWING: Figure 1

Description

The present invention relates to a physical condition monitoring system and a bed system.

In the care of inpatients in hospitals and the care of residents of long-term care facilities, patients and long-term care recipients may wear diapers. Further, in order to detect the presence of defecation or urination in a diaper and change the diaper at an appropriate timing, the systems described in Patent Document 1 and Patent Document 2 have been proposed.

In Patent Document 1, the presence or absence of excretion of the subject is determined based on the position of the total center of gravity applied to the bed, and the respiratory component separated from the load applied to the bed (the component that vibrates according to the subject's breathing). Describes a physical condition monitoring system that determines based on comparison with the position of the respiratory center of gravity determined based on.

Patent Document 2 describes an excretion detection system that detects excretion of a care recipient or the like based on a change in humidity of gas sucked from a mounting table on which the care recipient or the like is placed via a gas path. There is.

Japanese Unexamined Patent Publication No. 2018-19763 Japanese Unexamined Patent Publication No. 2013-78566

If the patient or the care recipient cannot properly detect the excretion, the patient or the care recipient may be left with the diaper in a dirty state, for example. On the contrary, if a false detection that the patient or the care recipient has excretion is made when the patient or the care recipient does not have the excretion, unnecessary access to the patient or the care recipient increases, which is annoying to the patient or the care recipient. Instead, it puts an unnecessary burden on medical staff, long-term care workers, etc.

Therefore, it is desired to enable appropriate detection of excretion, especially defecation in patients and long-term care recipients, and to enable necessary measures such as changing diapers at appropriate timing. .. As a result, the QOL (quality of life) of patients, long-term care workers, etc. can be improved, and at the same time, the burden on medical staff, long-term care workers, etc. can be reduced.

In view of the above, it is an object of the present invention to provide a physical condition monitoring system and a bed system capable of detecting that a subject has defecation, or that defecation or urination has occurred with higher accuracy. ..

According to the first aspect of the present invention,
A physical condition monitoring system that monitors the physical condition of the subject on the bed.
A plurality of load detectors provided on the bed or under the legs of the bed to detect the load of the subject, and
An odor detection unit that detects the odor on the bed, and
A predictive motion estimation unit that estimates the defecation predictive motion of the subject based on the time variation of the detected load of the subject, and the predictive motion estimation unit.
Provided is a physical condition monitoring system including an excretion determination unit that determines the presence or absence of defecation by the subject based on the detection result of the odor detection unit and the estimation result of the predictive motion estimation unit.

The physical condition monitoring system of the first aspect may further include a center of gravity position calculation unit that obtains a temporal variation of the center of gravity position of the subject based on the detected load. In the physical condition monitoring system of the first aspect, the predictive motion estimation unit may estimate the defecation predictive motion of the subject based on the temporal variation of the position of the center of gravity of the subject.

The physical condition monitoring system of the first aspect is based on the center of gravity position calculation unit that obtains the temporal variation of the center of gravity position of the subject based on the detected load, and the movement distance of the center of gravity position that moves within a predetermined time. Therefore, a large body movement component that fluctuates according to a large body movement different from the breath of the subject is determined from the time fluctuation of the center of gravity position, and the large body movement component is removed from the time fluctuation of the center of gravity position. Based on the body movement component removing unit and the movement direction of the center of gravity position, a small body movement component that fluctuates according to a small body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the center of gravity is determined. A small body movement component removing unit that removes the small body movement component from the temporal fluctuation of the position may be further provided. In the physical condition monitoring system of the first aspect, the excretion determination unit removes the detection result of the odor detection unit, the estimation result of the predictive motion estimation unit, and the large body movement component and the small body movement component. The excretion state of the subject may be determined based on the temporal variation of the position of the center of gravity.

In the physical condition monitoring system of the first aspect, the large body movement component and the small body movement component are removed based on the movement distance of the center of gravity position or the frequency of the temporal fluctuation of the detected load. Further may be provided with a defecation urination component specifying unit that specifies a defecation urination component that fluctuates according to the defecation and / or urination of the subject from the temporal fluctuation of the center of gravity position. In the physical condition monitoring system of the first aspect, the excretion determination unit is based on the detection result of the odor detection unit, the estimation result of the predictive motion estimation unit, and the identification result of the defecation / urination component identification unit. The excretory state of the subject may be determined.

In the physical condition monitoring system of the first aspect, the determination of the excretion state may include the presence or absence of excretion and the determination of whether the excretion is defecation, urination, or flatulence.

In the physical condition monitoring system of the first aspect, the predictive motion estimation unit may estimate the defecation predictive motion of the subject based on the temporal variation of the position of the center of gravity of the subject.

According to the second aspect of the present invention,
A physical condition monitoring system that monitors the physical condition of the subject on the bed.
A plurality of load detectors provided on the bed or under the legs of the bed to detect the load of the subject, and
A center of gravity position calculation unit that obtains a temporal variation in the center of gravity position of the subject based on the detected load, and a center of gravity position calculation unit.
Based on the movement distance of the center of gravity position that moves within a predetermined time, a large body movement component that fluctuates according to a large body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the center of gravity position is determined. A large body movement component removing unit that removes the large body movement component from the temporal fluctuation of
Based on the moving direction of the center of gravity position, a small body movement component that fluctuates according to a small body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the temporal fluctuation of the center of gravity position is used to determine the small body movement component. A small body movement component removing part that removes small body movement components,
An odor detection unit that detects the odor on the bed, and
A body including an excretion determination unit that determines the excretion state of the subject based on the temporal fluctuation of the position of the center of gravity from which the large body movement component and the small body movement component are removed and the detection result of the odor detection unit. A status monitoring system is provided.

In the physical condition monitoring system of the second aspect, the large body movement component and the small body movement component are removed based on the movement distance of the center of gravity position or the frequency of the temporal fluctuation of the detected load. Further may be provided with a defecation urination component specifying unit that specifies a defecation urination component that fluctuates according to the defecation and / or urination of the subject from the temporal fluctuation of the center of gravity position. In the physical condition monitoring system of the second aspect, the excretion determination unit may determine the excretion state of the subject based on the identification result of the defecation / urination component identification unit and the detection result of the odor detection unit.

In the physical condition monitoring system of the first and second aspects, the odor detecting unit may be a total volatile organic compound (TVOC) sensor and / or a nitrogen dioxide sensor.

In the physical condition monitoring system of the first and second aspects, the plurality of load detectors are four load detectors, each of which is installed under four legs provided at the four corners of the bed. May be good.

According to the third aspect of the present invention,
Bed and
A bed system comprising the physical condition monitoring system of the first aspect or the second aspect is provided.

According to the physical condition monitoring system and the bed system of the present invention, it is possible to detect that the subject has defecation, or that the subject has defecation or urination with higher accuracy.

FIG. 1 is a block diagram showing a configuration of a physical condition monitoring system according to an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the arrangement of the load detector and the odor detection unit with respect to the bed. FIG. 3 is a block diagram showing the configuration of the odor detecting unit. FIG. 4 is a flowchart showing a procedure of a physical condition monitoring method using a physical condition monitoring system. FIG. 5A is an example of the temporal fluctuation of the center of gravity of the subject when the subject on the bed takes a defecation signing motion, and FIG. 5B is an example when the subject on the bed takes a defecation signing motion. This is an example of the temporal fluctuation of the load signal of. FIG. 6 (a) is another example of the temporal fluctuation of the subject's center of gravity when the subject on the bed takes a defecation sign motion, and FIG. 6 (b) shows the subject on the bed taking a defecation sign motion. It is another example of the temporal fluctuation of the load signal at the time. FIG. 7 (a) is still another example of the temporal fluctuation of the subject's center of gravity when the subject on the bed performs the defecation sign motion, and FIG. 7 (b) shows the subject on the bed performing the defecation sign motion. It is yet another example of the temporal fluctuation of the load signal at the time of taking. FIG. 8 is a block diagram showing a configuration of a defecation / urination locus determination unit. FIG. 9 is a flowchart showing the procedure of the defecation / urination locus determination process. FIG. 10A shows an example of the center of gravity locus of the subject, and FIG. 10B shows the center of gravity locus obtained by converting the center of gravity locus shown in FIG. 10A to a low sampling frequency. 11 (a), 11 (b), and 11 (c) show a locus obtained by removing a large body movement locus from the center of gravity locus of the subject on the bed shown in FIG. 10 (a). FIG. 12 is an explanatory diagram illustrating a method of identifying a small body motion locus by analyzing a motion vector. FIG. 13A is an example of the detection result of the total volatile organic compound (TVOC) sensor. FIG. 13B is an example of the detection result of the nitrogen dioxide sensor. FIG. 14A is another example of the detection result of the TVOC sensor. FIG. 14B is another example of the detection result of the nitrogen dioxide sensor. FIG. 15A is still another example of the detection result of the TVOC sensor. FIG. 15B is still another example of the detection result of the nitrogen dioxide sensor. FIG. 16 is a flowchart showing the procedure of the excretion state determination step. FIG. 17 is a flowchart showing the procedure of the excretion state determination step of the modified example. FIG. 18 is an explanatory diagram illustrating a method of determining the moving direction of the motion vector. FIG. 19 is a block diagram showing the overall configuration of the bed system according to the modified example.

<Embodiment>
When the physical condition monitoring system 100 (FIG. 1) of the embodiment of the present invention is used together with the bed BD (FIG. 2) to monitor the physical condition of the subject S on the bed BD, specifically, the excretion state. Will be described as an example.

As shown in FIG. 1, the physical condition monitoring system 100 of the embodiment mainly includes a load detection unit 1, an odor detection unit 2, a control unit 4, and a storage unit 5. The load detection unit 1, the odor detection unit 2, and the control unit 4 are connected via an A / D conversion unit 3. A display unit 6, a notification unit 7, and an input unit 8 are further connected to the control unit 4.

The load detection unit 1 includes four load detectors 11, 12, 13, and 14 (FIG. 2). Each of the load detectors 11, 12, 13, and 14 is a load detector that detects a load using, for example, a beam-shaped load cell. Such load detectors are described, for example, in Japanese Patent No. 4829020 and Japanese Patent No. 4002905. The load detectors 11, 12, 13 and 14, respectively, are connected to the A / D conversion unit 3 by wiring or wirelessly.

As shown in FIG. 2, the four load detectors 11 to 14 of the load detector ₁ were attached to the lower ends of the legs BL 1, BL ₂ , BL ₃ , and BL _{4 at the four corners of the bed BD used by the subject S.} It is placed under casters C ₁ , C ₂ , C ₃ , and C _{4, respectively.}

As shown in FIG. 3, the odor detecting unit 2 includes a main body unit 21 and suction flow paths 22a to 22f.

The main body 21 is installed on the floor near the bed BD as an example. The main body 21 includes a total volatile organic compound (TVOC) sensor 211 and a nitrogen dioxide sensor 212. The main body 21 is connected to the A / D conversion unit 3 by wiring or wirelessly.

Each of the suction flow paths 22a to 22f is a flow path that guides the air in the vicinity of the buttocks of the subject S on the bed BD to the TVOC sensor 211 and the nitrogen dioxide sensor 212 of the main body 21. Each of the suction flow paths 22a to 22f is, for example, a branch pipe made of resin, and has one upstream end and two downstream ends.

Suction ports Pa to Pf are defined at the upstream ends of the suction flow paths 22a to 22f. As shown in FIG. 2, the suction ports Pa to Pf are located on one side of the central portion of the bed BD in the length direction (X direction) and in the central portion in the width direction (Y direction) (that is, in the length direction). Areas located near the buttocks of subject S lying along the bed BD) are arranged in a matrix. The distance between the two suction ports adjacent to each other in the length direction and the distance between the two suction ports adjacent to each other in the width direction may be, for example, about 30 to 100 mm.

Each of the six suction ports Pa to Pf is arranged so that the odor emitted from the diaper worn by the subject S can be detected, and specifically, specifically, it is arranged under the sheets, for example.

One of the downstream ends of the suction flow paths 22a to 22f is connected to the TVOC sensor 211, and the other is connected to the nitrogen dioxide sensor 212.

The odor detecting unit 2 further includes a suction mechanism (not shown). The suction mechanism is, for example, a small air pump. The suction mechanism applies a negative pressure to the suction channels 22a to 22f so as to send air in the vicinity of the suction ports Pa to Pf to the TVOC sensor 211 and the nitrogen dioxide sensor 212. The suction mechanism may be arranged, for example, in the suction flow paths 22a to 22f, or may be arranged on the downstream side of the TVOC sensor 211 and the nitrogen dioxide sensor 212.

The A / D conversion unit 3 includes an A / D converter that converts an analog signal from the load detection unit 1 and the odor detection unit 2 into a digital signal, and the load detection unit 1, the odor detection unit 2, and the control unit 4 have an A / D converter. They are connected by wiring or wirelessly, respectively.

The control unit 4 is a dedicated or general-purpose computer, and has a center of gravity position calculation unit 41, a predictive motion estimation unit 42, a defecation / urination trajectory determination unit 43, and an excretion state determination unit (excretion determination unit) 44 built therein. There is.

The storage unit 5 is a storage device for storing data used in the physical condition monitoring system 100, and for example, a hard disk (magnetic disk) can be used.

The display unit 6 is an image display device such as a liquid crystal monitor that displays the information output from the control unit 4 to the user of the physical condition monitoring system 100.

The notification unit 7 includes a device that aurally performs a predetermined notification based on the information from the control unit 4, for example, a speaker.

The input unit 8 is an interface for performing a predetermined input to the control unit 4, and may be a keyboard and a mouse.

An operation of monitoring the physical condition (specifically, the excretion state) of the subject on the bed by using the physical condition monitoring system 100 will be described.

As shown in the flowchart of FIG. 4, the subject's physical condition is monitored by using the physical condition monitoring system 100 in the load detection step S1 for detecting the subject's load, the position of the center of gravity of the subject based on the detected load (load value), and the position of the center of gravity of the subject. And the center of gravity trajectory calculation step S2 for calculating the locus of temporal fluctuation of the center of gravity position (center of gravity locus), the predictive motion for presuming that there was a subject's motion (defecation predictive motion, which will be described in detail later) that occurs prior to the subject's defecation. Estimating step S3, defecation / urination trajectory determination step S4 for determining that there was a locus of center of gravity movement (defecation / urination locus; details will be described later) that occurs with defecation / urination of the subject, odor detection step for detecting the subject's odor. S5, a defecation state determination step S6 for determining the presence or absence of defecation (that is, defecation, urination, and release) in the subject based on the results of the predictive motion estimation step S3, the defecation / urination trajectory determination step S4, and the odor detection step S5, and the excretion. The display step S7 for displaying the result of the state determination step S6 is included.

[Load detection process]
In the load detection step S1, the load of the subject S on the bed BD is detected by using the load detectors 11, 12, 13, and 14. The load of the subject S on the bed BD is distributed and applied to the load detectors 11 to 14 arranged under _{the legs BL 1 to} BL _{4 at the four corners of the bed BD, and is dispersedly detected by these.} Here, it is assumed that the weight of the bed BD is tare, but tare is not essential.

Each of the load detectors 11 to 14 detects the load (load change) and outputs it as an analog signal to the A / D conversion unit 3. The A / D conversion unit 3 converts an analog signal into a digital signal with a sampling period of, for example, 5 milliseconds, and outputs the digital signal (hereinafter referred to as “load signal”) to the control unit 4. In the following, the load signals obtained by digitally converting the analog signals output from the load detectors 11, 12, 13, and 14 in the A / D conversion unit 3 are the load signals s ₁ , s ₂ , s ₃ , and s, respectively. Call it _4.

[Center of gravity trajectory calculation process]
In the center of gravity trajectory calculation step S2, the center of gravity position calculation unit 41 determines the position G (X, Y) of the center of gravity G of the subject S on the bed BD based on _{the load signals s 1 to s 4 from the load detectors 11 to 14.} It is calculated with a predetermined period T (for example, equal to the above sampling period of 5 milliseconds), and the temporal variation of the position of the center of gravity G of the subject S (center of gravity locus GT) is obtained. Here, (X, Y) indicates the coordinates on the XY coordinate plane with the center of the bed BD as the origin O, X in the length direction, and Y in the width direction (FIG. 2).

The calculation of the position G (X, Y) of the center of gravity G by the center of gravity position calculation unit 41 is performed by the following calculation. That is, G (X, Y) sets the coordinates of the load detectors 11, 12, 13, and 14 to (X ₁₁ , Y ₁₁ ), (X ₁₂ , Y ₁₂ ), (X ₁₃ , Y ₁₃ ), and (X _{14), respectively.} , Y ₁₄ ), the load detection values of the load detectors _{11 , 12 , 13 , and 14} are W 11, W 12, W 13, and W 14, respectively, and are calculated by the following equations.

The center of gravity position calculation unit 41 calculates the position G (X, Y) of the center of gravity G in a predetermined sampling period T based on the above formulas 1 and 2, and the time of the position G (X, Y) of the center of gravity G. The target fluctuation, that is, the center-of-gravity locus GT is obtained and stored in, for example, the storage unit 5.

[Predictive motion estimation process]
In the predictive motion estimation step S3, the predictive motion estimation unit 42 receives the load signals s ₁ , s ₂ , s ₃ , s ₄ , and / or the center of gravity G calculated based on the load signals s 1, s 2, s 3, and / or the load signals from the load detection unit 1. It is presumed that the subject S performed a defecation signing motion.

In the present invention and the present specification, the "defecation sign motion" means a predetermined motion performed by a subject on the bed with a high probability prior to defecation.

The predictive motion estimation unit 42 estimates that the subject S has performed a defecation predictive motion based on the following principle.

Human defecation is performed by discharging the stool accumulated in the large intestine from the anus through the rectum. Here, in general, the following three forces contribute to defecation.

The first force is the force given to the stool by the peristaltic movement of the large intestine. This force moves the stool that collects in the large intestine to the rectum.

The second force is gravity. This force assists the movement of stool in the rectum toward the anus.

The third force is the external pressure exerted on the rectum by human beings. Specifically, this external pressure is caused by tension of the respiratory muscles and abdominal muscles, for example. This force moves the stool in the rectum toward the anus and expels it out of the body through the anus.

Here, it is said that the peristaltic movement of the large intestine is unlikely to occur when a human is lying on the bed. Also, when a person is lying on the bed, the position of the stool in the rectum is below the anus, and gravity does not help defecation.

Furthermore, when a person is lying on the bed, it is difficult to step on because the foot cannot be stably stepped on. In addition, since the direction of the force transmitted when the force is applied to the respiratory muscles and the abdominal muscles is deviated, the external pressure applied to the rectum due to the strain is also reduced.

That is, when a human is lying on the bed, all three forces contributing to defecation are weakened or eliminated. Therefore, it is usually not easy to defecate while lying on the bed.

According to the findings of the inventor of the present invention, a patient or a care recipient who tries to defecate on a bed has a high probability of changing his / her posture so that at least one of the above three forces becomes large. The "defecation sign motion" is an motion performed by a patient, a care recipient, or the like in order to cause such a posture change.

The inventor of the present invention further conducted diligent research on fluctuations in the detection values of the load detectors placed under the four legs of the bed, and / or the position of the center of gravity of the subject on the bed calculated based on these fluctuations. Based on the variability, it was found that it was possible to presume that the subject performed a defecation predictive action.

Based on the above findings of the inventor of the present invention, the predictive motion determining unit 42 of the present embodiment presumes that the subject S has performed the defecation predictive motion. _{Specifically, for example, the subject S is based on the fact that the fluctuations of the load signals s 1 to s 4} from the load detection unit 1 and / or the fluctuations of the center of gravity G calculated by the center of gravity position calculation unit 41 show a predetermined pattern. Is presumed to have performed a defecation sign action.

An example of a defecation sign movement is a movement in which the person is in a lateral position and grabs the fence of the bed. The changes in the center of gravity G and the changes in the load signals s _{1 to s 4} when such a defecation sign motion occurs are shown in FIGS. 5 (a), 5 (b), 6 (a), and (b). As shown in.

5 (a) is the subject S to the time t ₀ is taken supine in the vicinity of the widthwise center of the bed BD is, become a right lateral position at time t ₁ by grasping the right fence bed BD and The center of gravity trajectory GT that occurs when the user puts his foot on the fence on the right side and then _{intermittently goes from time t 1} to time t _{2 is shown.} The center of gravity G of the subject S at time t _{0 is G (t 0} ), and the center of gravity G of the subject S at _{times t 1 to t 2 is G (t 1 to t 2} ). Although not shown, G (t _{1 to t 2} ) vibrates slightly intermittently according to the strain of subject S. The vibrations of the load signals s _{1 to s 4} corresponding to this vibration are shown twice in the period _{of time t 1 to t 2 in} FIG. 5 (b).

6 (a) is the subject S to the time t ₀ is taken supine in the vicinity of the widthwise center of the bed BD is, at time t ₁ is the left lateral decubitus position gripping the left fence bed BD and The center of gravity trajectory GT that occurs when the foot is put on the fence on the left side and then _{intermittently goes from time t 1} to time t _{2 is shown.} The center of gravity G of the subject S at time t _{0 is G (t 0} ), and the center of gravity G of the subject S at _{times t 1 to t 2 is G (t 1 to t 2} ). Although not shown, G (t _{1 to t 2} ) vibrates slightly intermittently according to the strain of subject S. The vibrations of the load signals s _{1 to s 4} in response to this vibration are shown twice in the period _{of time t 1 to t 2 in} FIG. 6 (b).

By being in the lateral decubitus position in this way, the position of the stool in the rectum and the position of the anus can be made substantially horizontal. Therefore, the force to be applied to the rectum (that is, the third force) can be reduced by the force.

In addition, it is easier to move by holding the bed fence in the lateral position and putting your feet on the bed fence. Furthermore, by being in the lateral decubitus position, the pressing force generated by the tension of the respiratory muscles and the abdominal muscles can be more efficiently transmitted to the rectum.

Another example of a defecation signing motion is the motion of grabbing the bed fence while in the supine position. The changes in the center of gravity G and the changes in the load signals s _{1 to s 4} when such a defecation sign motion occurs are as shown in FIGS. 7 (a) and 7 (b).

7 (a) is the subject S to the time t ₀ is taken supine in the vicinity of the widthwise center of the bed BD is, the arms remain supine time t ₁ is moved to the head side of the bed BD It shows the center of gravity trajectory GT that occurs when the fence on the head side is grasped and both feet are bent to reach the posture where the sole of the foot is pressed against the upper surface of the mattress, and then _{intermittently from time t 1} to time t _2. .. The center of gravity G of the subject S at time t _{0 is G (t 0} ), and the center of gravity G of the subject S at _{times t 1 to t 2 is G (t 1 to t 2} ). Although not shown, G (t _{1 to t 2} ) vibrates slightly intermittently according to the strain of subject S. The vibrations of the load signals s _{1 to s 4} in response to this vibration are shown twice in the period _{of time t 1 to t 2 in} FIG. 7 (b).

In this way, by grasping the fence of the bed and taking a posture in which the soles of the feet are in contact with the mattress, it becomes easier to move and the third force can be increased.

In the predictive motion estimation unit 42, the center of gravity G of the subject G has drawn the center of gravity locus GT as shown in FIGS. 5 (a) to 7 (a), and / or the load signals s _{1 to s 4} are shown in FIG. 5 ( b) It can be presumed that the subject S performed a defecation signing motion based on the fluctuations shown in FIGS. 7 (b). The moving distance of the center of gravity G in the bed width direction when the subject S is in the lateral decubitus position is usually larger than the moving distance when the subject S is simply in the lateral decubitus position because he / she grips the fence. Further, the vibration of the center of gravity G and the load signals s _{1 to s 4} accompanying the movement of the subject S can also be one of the judgment factors when estimating the defecation sign motion.

[Defecation / urination trajectory determination process]
In the defecation / urination trajectory determination step S4, the defecation / urination trajectory determination unit 43 specifies the defecation / urination trajectory from the center of gravity trajectory GT calculated in the center of gravity trajectory calculation step S2.

Defecation / urination trajectory is specified based on the following principle.

As described in JP-A-2018-126423, the biological activity of Subject S can be classified into "large body movement", "small body movement", and "breathing". Trajectories of temporal fluctuations in the position of the center of gravity G in response to large body movements (hereinafter referred to as "large body movement trajectories"), loci of temporal fluctuations in the position of the center of gravity G in response to small body movements (hereinafter referred to as "small body movements") The locus (referred to as "trajectory") and the locus of temporal fluctuation of the position of the center of gravity G according to breathing (hereinafter referred to as "respiratory vibration locus") show different characteristics.

In the present specification and the present invention, the "large body movement" means a relatively large body movement of a subject accompanied by movement of the torso (trunk), and specifically, for example, turning over or getting up. Is. When a subject experiences large body movements, the orientation of the subject's body axis (the orientation in which the subject's spine extends) generally changes.

Looking at a large body movement from the viewpoint of the state of temporal fluctuation of the position of the center of gravity G, in general, a large body movement is a movement of the center of gravity G over a relatively long distance that occurs within a predetermined period, for example, the center of gravity G. It is a body movement that causes movement at a relatively high speed. Therefore, for example, a body movement that causes a movement of the center of gravity exceeding a predetermined distance PD1 in a predetermined period PP and / or a body movement that causes a movement of the center of gravity at a speed exceeding a predetermined value V1 can be defined as a large body movement. Alternatively, based on the difference from the temporal fluctuation of the position of the center of gravity G caused by a small body movement, for example, the center of gravity G is larger than a predetermined time compared with the moving distance of the center of gravity G due to a small body movement within a unit time. The body movement that moves the body can also be defined as a large body movement. The large body movement locus is such a locus of movement of the center of gravity G.

In the present specification and the present invention, the "small body movement" means a relatively small body movement of a subject without movement of the torso (trunk), and specifically, for example, limbs and head. Exercise only for the club.

Looking at a small body movement in terms of the state of temporal fluctuation of the position of the center of gravity G, in general, a small body movement is a movement of the center of gravity G over a relatively short distance within a unit time, for example, a relatively low velocity of the center of gravity G. It is a body movement that causes movement in. Therefore, for example, a body movement that causes a movement of the center of gravity of a predetermined distance PD2 (<PD1) in a predetermined period PP and / or a body movement that causes a movement of the center of gravity of a predetermined value V2 (<V1) is defined as a small body movement. can do.

Further, a small body movement causes a movement of the center of gravity of about a predetermined distance PD2 in the PP for a predetermined period, or the movement speed is about a predetermined value V2 and has no periodicity, and is in a direction different from the body axis direction of the subject S. The body movement that causes the movement of the center of gravity toward the center of gravity may be defined as a small body movement. The small body movement locus is such a locus of movement of the center of gravity G.

The state of the temporal fluctuation of the position of the center of gravity G according to the respiration is as follows. Human breathing is performed by moving the thorax and diaphragm to inflate and contract the lungs. Here, during inspiration, that is, when the lungs expand, the diaphragm descends and the internal organs also move downward. On the other hand, when exhaling, that is, when the lungs contract, the diaphragm rises upward and the internal organs also move upward. As described in Patent No. 6,105,703 issued to the applicant, since breathing accompanies the vertical movement of the internal organs, the center of gravity G of the subject is moved in the vertical direction (direction of the spine), that is, the body axis direction due to the breathing. It vibrates almost along. Therefore, it is possible to distinguish between respiration that appears as a vibration of the center of gravity in the body axis direction and small body movement that appears as a movement of the center of gravity in a direction different from the body axis direction.

The inventor of the present invention examined the movement of the center of gravity of the subject on the bed in more detail, and in addition to the above-mentioned movement of the center of gravity according to the body movement and respiration of the subject, it is also characteristic when the subject defecates and urinates. It was found that the movement of the center of gravity can be observed.

Specifically, when the subject on the bed urinates into the diaper, the subject's center of gravity moves at a relatively low velocity V3 (<V2) along the subject's body axis direction in accordance with the urination, and the subject's foot. Move to the side. This is because the urine of the subject having a predetermined weight moves to the foot side of the subject by urination. Similarly, when the subject defecates, the center of gravity of the subject moves toward the foot side of the subject at a relatively low velocity V4 (<V2) along the body axis direction of the subject. In the present invention and the present specification, such a locus of movement of the center of gravity G is referred to as a “defecation / urination locus”.

Here, the physical condition monitoring system 100 of the first embodiment calculates the position of the center of gravity of the subject S as the position of the center of gravity of the weight including the clothes and diapers of the subject. Therefore, the urine and stool excreted in the diaper (that is, the urine and stool excreted outside the body of the subject S) are also used to calculate the position of the center of gravity of the subject S in the same manner as when they are present in the body of the subject S. affect.

The defecation / urination locus determination unit 43 has a large body movement locus, a small body movement locus, and a respiratory vibration locus having different characteristics as described above. , And the respiratory vibration trajectory, and the defecation / urination trajectory.

Specific examples of the method by which the defecation / urination locus determination unit 43 specifies the defecation / urination locus of the subject S are as follows.

As shown in FIG. 8, the defecation / urination locus determination unit 43 identifies the body locus acquisition unit 430 that extracts the subject S's center of gravity locus from the storage unit 5, and the subject S's large body movement locus included in the extracted body locus. A large body movement locus removing part (large body movement component removing part) 431 and a small body movement locus removing part (small body) that identifies and removes the small body movement locus of the subject S included in the extracted center of gravity locus GT. Dynamic component removing part) 432 and a locus distinguishing part (identification of defecation and urination component) that distinguishes the center of gravity trajectory GT from which a large body movement trajectory and a small body movement trajectory are removed into a respiratory vibration trajectory and a stool / urination trajectory (stool / urination component). Part) 433 and.

As shown in FIG. 9, the defecation / urination trajectory determination step S4 executed by the defecation / urination trajectory determination unit 43 includes a large body movement trajectory removal step S31, a small body movement trajectory removal step S32, and a trajectory distinction step S33. ..

[Large body movement trajectory removal process]
In the large body movement locus removing step S31, first, the center of gravity locus GT of the subject S in a predetermined period is taken out from the storage unit 5 by using the center of gravity locus acquisition unit 430. An example of the center of gravity locus GT taken out is as shown in FIG. 10 (a).

The center-of-gravity locus GT shown in FIG. 10A shows that the subject S makes one round trip in the left-right direction on the bed due to a large body movement (turning over, etc.). Further, it shows how the center of gravity G of the subject S moves in the regions A, B, and C, respectively, during the period in which no large body movement occurs (hereinafter, referred to as “stable position period”). The movement of the center of gravity G within regions A, B, and C is caused by subject S's small body movements, respiration, and urination.

The defecation / urination locus determination unit 43 then uses the large body movement locus removing unit 431 to identify the large body movement locus of the subject S from the center of gravity trajectory GT. The large body movement locus removing unit 431 analyzes the position of the center of gravity G at each sampling time, and based on the definition of "large body movement", appropriately obtains a locus of movement of the center of gravity G (large body movement locus) according to the large body movement. Can be identified. Specifically, for example, when the center of gravity G moves beyond a predetermined distance within a predetermined time, it is specified that the locus of this movement is a large body movement locus.

The large body movement locus removing unit 431 determines whether or not the center of gravity G has moved beyond a predetermined distance within a predetermined time by using the following method. First, the center-of-gravity locus GT shown in FIG. 10A is converted into the center-of-gravity locus GT1 converted to a lower sampling frequency (FIG. 10B). The conversion to a lower sampling frequency can be performed by thinning out the data of the center of gravity position G acquired in the sampling period of 5 milliseconds or by performing a moving average process. Alternatively, the center-of-gravity locus GT can be frequency-decomposed and a predetermined low-frequency component can be extracted by a low-pass filter.

The low sampling frequency has a short period (large frequency) sufficient to extract a large body movement, and is not affected by changes in the center of gravity due to other factors such as small body movement and respiration. It is desirable to have a long period (small frequency).

In FIG. 10B, the locus between the points A1 and the point B1 moves, for example, to the right over a predetermined distance within a predetermined time. Therefore, the large body movement locus removing unit 431 identifies the locus in this section as a large body movement locus. Similarly, the locus between the points B2 and C1 also moves, for example, to the left over a predetermined distance within a predetermined time. Therefore, the large body movement locus removing unit 431 identifies the locus in this section as a large body movement locus.

After identifying the large body movement locus, the large body movement locus removing unit 431 removes the large body movement locus from the center of gravity locus GT, and the center of gravity locus GT from which the large body movement locus is removed is used as the small body movement locus removing unit 432. send. 11 (a) to 11 (c) show the center of gravity locus GT shown in FIG. 10 (a) from which a large body movement locus is removed. 11 (a) is the center of gravity locus GT in the region A of FIG. 10 (a), FIG. 11 (b) is the center of gravity locus GT in the region B of FIG. 10 (a), and FIG. 11 (c) is FIG. 10 (a). It is the center of gravity locus GT in the region C. Each of these corresponds to the center-of-gravity locus GT during the stable posture period (the period during which the subject does not exhibit large body movements).

[Small body movement trajectory removal process]
In the subsequent small body movement locus removing step S32, the defecation / urination locus determination unit 43 uses the small body movement locus removing unit 432 to identify the small body movement locus included in the center of gravity locus GT from which the large body movement locus is removed. do. A specific step will be described by taking as an example a step of identifying a small body movement locus included in the center of gravity locus GT of the region C (FIG. 11 (c)) and removing the small body movement locus.

In FIG. 11 (c), the center-of-gravity locus GT represents the parts gt1, gt3, and gt5 representing the vibration of the center of gravity G due to breathing, the part gt2 representing the movement of the center of gravity G due to a small body movement, and the movement of the center of gravity G due to urination. Includes partial gt4 and. The portions gt1, gt3, and gt5 representing the movement of the center of gravity G due to respiration indicate periodic vibration. The vibration trajectories of the portions gt1, gt3, and gt5 actually appear overlapping on one axis along the vibration direction, but in FIG. 11C, they are orthogonal to the body axis direction for explanation. It is drawn by shifting it in the direction. The same applies to FIGS. 11 (a), 11 (b), and 12.

The portion gt2 representing the movement of the center of gravity G due to a small body movement is a locus extending in a direction different from the body axis direction, and the portion gt4 representing the movement of the center of gravity G due to urination is a locus extending in the body axis direction.

Therefore, the small body movement locus removing unit 432 identifies the small body movement locus based on the fact that the small body movement locus extends in a direction different from the body axis direction (that is, the direction of respiratory vibration). As an example, the small body movement locus removing unit 432 identifies the small body movement locus of the subject S by a method of removing outliers.

Specifically, it is assumed that the center-of-gravity locus shown in FIG. 11 (c) includes 48 motion vectors from _{v 1 to v 48 as shown in FIG.} First, the small body motion trajectory removing unit 432 obtains the direction of the _{mode vector v f from these 48 motion vectors.} The motion vectors v _{1 to v 48} each have an orientation, but as shown in FIG. 12, most of the motion vectors v _{1 to v 48} have the same orientation with each other. The direction of the mode vector v _{f is equal to the direction in which the motion vectors v 1 to v 48} appear most frequently, and as is clear from FIG. 12, the motion vectors v _{1 to v 11} and v _{15 to v 48} Equal to either direction (as mentioned above, these motion vectors are tilted relative to each other for convenience of illustration, but in reality they are all approximately along the body axis direction).

Next, the small body motion trajectory removing unit 432 makes an angle of 180 ° with respect to its own direction and the direction of the most frequent value vector v _f (or the most frequent value vector v _{f) in the motion vectors v 1 to v 48.} A motion vector whose difference from the orientation is less than or equal to a certain threshold is regarded as a majority vector, and its own orientation and the direction of the most frequent value vector v _f (and an angle of 180 ° with respect to the most frequent value vector v _f). A motion vector whose difference from (direction with) is larger than a certain threshold is regarded as a minority vector. _{Specifically, the motion vectors v 1 to v 11} and v _{15 to v 48} having directions substantially along the body axis direction of the subject S are regarded as the majority vector, and the other motion vectors v _{12 to v 14} are the minority. Treat as a vector and extract. The locus represented by the minority vector extracted in this way corresponds to a small body movement locus.

After determining the small body movement locus, the small body movement locus removing unit 432 removes the small body movement locus from the center of gravity locus GT, and sends the center of gravity locus GT from which the small body movement locus is removed to the locus discrimination unit 433.

[Trajectory distinction process]
In the subsequent locus distinction step S33, the locus discrimination unit 433 distinguishes the center of gravity locus GT from which the large body movement locus and the small body movement locus are removed into a respiratory vibration locus and a defecation / urination locus (defecation urination component). The distinction between the respiratory vibration locus and the defecation / urination locus is specifically performed by, for example, specifying a linear movement of the center of gravity G over a predetermined distance along the same direction or substantially the same direction.

Specifically, the procedure is as follows. The locus distinguishing unit 433 receives the center-of-gravity locus GT from which the small body movement locus is removed from the small body movement locus removing unit 432. The received center-of-gravity locus GT is, for example, a locus from which the motion vectors v _{12 to v 14} are removed in the center-of-gravity locus GT of FIG.

The locus discrimination unit 433 analyzes the received center-of-gravity locus GT to specify a region in which the center-of-gravity G makes a linear movement of a predetermined distance or more along the same direction or substantially the same direction. This specification is performed, for example, by specifying a region in which motion vectors having the same or substantially the same orientation occur continuously in excess of a predetermined number. Alternatively, similarly to the large body movement locus removing unit 431, the position of the center of gravity G at each sampling time is referred to, and a region where the center of gravity G linearly moves by a predetermined distance or more along the same direction or substantially the same direction is specified. You may.

The locus distinguishing unit 433 determines that the locus of movement of the center of gravity G in the region is a defecation / urination locus after specifying a region in which the center of gravity G linearly moves along the same direction or substantially the same direction by a predetermined distance or more. Then, the other area is determined to be the respiratory vibration trajectory.

[Odor detection process]
In the odor detection step S5, the odor detection unit 2 detects the odor generated by the excretion of the subject S.

The odor detecting unit 2 applies a negative pressure to the suction channels 22a to 22f by using a suction mechanism (not shown). As a result, the air around the buttocks of the subject S on the bed BD is sucked into the suction flow paths 22a to 22f through the suction ports Pa to Pf at the ends of the suction flow paths 22a to 22f, and the TVOC of the main body portion 21. It is guided to the sensor 211 and the nitrogen dioxide sensor 212.

The TVOC sensor 211 of the main body 21 detects the amount of total volatile organic compounds (TVOC) contained in the air supplied to the TVOC sensor 211 via each of the suction channels 22a to 22f, and six suction channels. Is output to the A / D conversion unit 3 as six analog signals corresponding to the above. The A / D conversion unit 3 converts six analog signals into six digital signals with a sampling period of, for example, 5 milliseconds, and outputs the digital signals (hereinafter referred to as “TVOC signals”) to the control unit 4.

Hereinafter, the six digital signals output from the TVOC sensor 211 via the A / D conversion unit 3 are referred to as TVOC signals sa _{TVOC to} sf _TVOC . TVOC signals sa _{TVOC to} sf _TVOCs are digital signals indicating the amount of TVOC contained in the air in the vicinity of the suction ports Pa to Pf, respectively.

The nitrogen dioxide sensor 212 of the main body 21 detects the amount of _{nitrogen dioxide (NO 2} ) contained in the air supplied to the nitrogen dioxide sensor 212 via each of the suction channels 22a to 22f, and has six suction channels. Is output to the A / D conversion unit 3 as six analog signals corresponding to the above. The A / D conversion unit 3 converts six analog signals into six digital signals with a sampling period of, for example, 5 milliseconds, and outputs the digital signals (hereinafter referred to as “NO ₂ signals”) to the control unit 4.

Hereinafter, the six digital signals output from the nitrogen dioxide sensor 212 via the A / D conversion unit 3 are referred to as NO ₂ signals sa _{NO2 to} sf _NO2 . NO ₂ signal sa _{NO2 to} sf _NO2 is a digital signal indicating the amount of nitrogen dioxide contained in the air in the vicinity of the suction ports Pa to Pf, respectively.

The control unit 4 stores the received TVOC signals sa _{TVOC to} sf _TVOC and NO ₂ signals sa _{NO2 to} sf _NO2 in the storage unit 5.

13 (a), 14 (a), and 15 (a) _{show an example of TVOC signals sa TVOC to} sf _TVOC , and FIGS. 13 (b), 14 (b), and 15 (b) show. NO ₂ signal sa _{NO2 to} sf _NO2 is shown as an example. In each figure, the TVOC signal _{sa TVOC} and NO ₂ signal _{sa NO2} by the solid line, the TVOC signal _{sb TVOC} and NO ₂ signal _{sb NO2} by the dotted line, the TVOC signal _{sc TVOC} and NO ₂ signal _{sc NO2} by broken lines, TVOC signal sd _{The TVOC} and NO ₂ signal sd _NO2 are indicated by a long dashed line, the TVOC signal se _TVOC and NO ₂ signal se _NO2 are indicated by a long-dashed line, and the TVOC signal sf _TVOC and NO ₂ signal sf _NO2 are indicated by a long two-dot chain line.

13 (a) and 13 (b) are 60-minute records measured at the same timing. 14 (a) and 14 (b) are 60-minute records measured at the same timing. 15 (a) and 15 (b) are 60-minute records measured at the same timing. On the other hand, FIGS. 13, 14, and 15 are measured at different timings from each other.

Regarding FIGS. 13 (a) and 13 (b), it is observed that the subject S on the bed BD defecates in the vicinity of the suction port Pe at around time 41 min.

In FIG. 13A, the signal values of _{the TVOC signals sa TVOC to} sf _TVOC corresponding to this defecation occur in the vicinity of the time 41 min (indicated by the vertical solid line). The vertical axis of FIGS. 13 (a) (and 14 (a) and 15 (a)) is a value corresponding to the resistance value of the sensor element, and decreases when the TVOC around the sensor element increases. ..

In FIG. 13B, the signal values of _{the NO2 signals sa NO2} , sb _NO2 , and sd _{NO2 to sf NO2} corresponding to this defecation occur in the vicinity of the time 41 min (indicated by the vertical solid line). NO2 signal sd _{The increase in the signal values of NO2} and se _NO2 is particularly large because the odor is emitted between the diaper and the leg.

Regarding FIGS. 14 (a) and 14 (b), it is observed that the subject S on the bed BD urinates in the vicinity of the suction port Pe at around 15 min.

In FIG. 14 (a), a slight decrease in the signal values (particularly se _{TVOC ) of the TVOC signals sa TVOC to sf TVOC} corresponding to this urination occurs in the vicinity of the time 15 min (indicated by the vertical solid line).

In FIG. 14 (b), the signal values of _{NO2 signals sa NO2 to} sf _{NO2 (particularly sc NO2} , sd _NO2 , se _NO2 , and sf _NO2 ) corresponding to this urination are shown in the vicinity of time 15 min (indicated by a vertical solid line). ) Slightly increased.

Since the range of the vertical axis is large in FIGS. 14 (a) and 14 (b), _{changes in the signal values of the TVOC signals sa TVOC to} sf _TVOC and changes in the signal values of the NO2 signals sa _{NO2 to} sf _{NO2 according to urination.} Although appearing to be insignificant, each signal value actually indicates a significant and detectable change in response to the subject's urination.

Regarding FIGS. 15 (a) and 15 (b), it is observed that the subject S on the bed BD performed flatulence in the vicinity of the suction port Pe at about 32 min.

In FIG. 15A, the signal values of _{the TVOC signals sa TVOC to sf TVOC} corresponding to the flatulence are lowered in the vicinity of the time 32 min (indicated by the vertical solid line).

In FIG. 15B, the signal values of _{the NO2 signals sa NO2 to} sf _NO2 in response to this flatulence increase in the vicinity of the time 32 min (indicated by the vertical solid line).

In this way, when the subject S excretes (defecation, urination, flatulence) _{, at least one signal value of the TVOC signal sa TVOC to sf TVOC} decreases, and at least one of the NO2 signals sa _{NO2 to} sf _NO2. The signal value rises.

[Excretion status determination process]
In the excretion state determination step S6, the excretion state determination unit 44 uses the results of the predictive motion estimation step S3, the defecation / urination trajectory determination step S4, and the odor detection step S5 to determine the presence or absence of excretion in the subject S and the excretion is defecation. , Excretion, or flatulence.

In the excretion state determination unit 44, odor is generated when the subject excretes (defecation, urination, and defecation), and when the subject defecates and urinates, the defecation / urination trajectory is observed. And, the excretion state is determined by utilizing the fact that the defecation sign movement is observed before the subject defecates.

Specifically, for example, the excretion state determination unit 44 determines the excretion state at a predetermined time (hereinafter, referred to as “determination target time”) according to the flowchart shown in FIG.

First, the excretion state determination unit 44 determines whether or not odor is generated in the vicinity of the buttocks of the subject S at the determination target time using the result of the odor detection step S5 (S41). When no odor is generated (S41, NO), it is determined that there is no excretion (S47), and the determination result is output to the display unit 6 (S48).

On the other hand, when the odor is generated in the vicinity of the buttocks of the subject S (S41, YES), the result of the predictive motion estimation step S3 is used for a predetermined period immediately before the determination target time (for example, about 40 to 80 seconds). (S42), it is confirmed whether or not the defecation signing motion has occurred during the period of (S42). When a sign motion has occurred (S42, YES), it is determined that there is defecation (S43), and the determination result is output to the display unit 6 (S48).

When no predictive motion has occurred (S42, NO), the result of the defecation / urination trajectory determination step S4 is used for a predetermined period immediately before the determination target time (for example, a period of about 20 to 80 seconds, or 60 seconds. It is confirmed whether or not the defecation / urination trajectory has occurred during the period of time (S44).

When a defecation / urination locus has occurred (S44, YES), it is determined that there is urination (S45), and the determination result is output to the display unit 6 (S48). On the other hand, when the defecation / urination locus does not occur (S44, NO), it is determined that there is flatulence (S46), and the determination result is output to the display unit 6 (S48).

The defecation state determination unit 44 performs the above determination according to the flowchart of FIG. 16 over time in a predetermined cycle (for example, about 30 to 120 seconds or about 60 seconds), and sequentially displays the determination results on the display unit 6. Output.

<Display process>
In the display step S7, the presence or absence of excretion of the subject S determined by the excretion state determination unit 44, and whether the excretion is defecation, urination, or flatulence is displayed on the monitor.

Specifically, for example, icons corresponding to defecation, urination, flatulence, and no excretion are displayed on the monitor. By visually recognizing the icon, the user of the physical condition monitoring system 100 can easily know that the subject S has defecation, that is, that the diaper needs to be changed immediately.

The physical condition monitoring system 100 may be configured so as to be notified by the notification unit 9 when the subject S defecates.

The effects of the physical condition monitoring system 100 of this embodiment are summarized below.

In the physical condition monitoring system 100 of the present embodiment, the excretion state determination unit 44 detects the odor by the odor detecting unit 2, and the predictive motion estimation unit 42 estimates that the subject S performs the defecation predictive motion. It is determined that S has defecation. When the physical condition monitoring system 100 of the present embodiment makes a determination in consideration of not only the detection result of the odor detection unit 2 but also the estimation result of the predictive motion estimation unit 42 in this way, urination, flatulence, etc. occur. It is possible to prevent erroneous determination of this as defecation, and it is possible to perform highly accurate defecation determination.

The physical condition monitoring system 100 of the present embodiment detects odor using the odor detection unit 2, estimates defecation predictive motion using the predictive motion estimation unit 42, and defecation / urination using the defecation / urination trajectory determination unit 43. The excretion state is determined based on the identification of the locus. Therefore, it is possible to determine not only the presence or absence of excretion of the subject S, but also whether the excretion is defecation, urination, or flatulence.

<Modification example>
In the physical information monitoring system 100 of the above-described embodiment, the following modified modes can also be adopted.

In the physical information monitoring system 100 of the above embodiment, the odor detecting unit 2 has a TVOC sensor 211, a nitrogen dioxide sensor 212, and six suction channels 22a to 22f, but is not limited thereto.

The main body 21 of the odor detecting unit 2 may have only one of the TVOC sensor 211 and the nitrogen dioxide sensor 212. Further, instead of the TVOC sensor 211 and / or the nitrogen dioxide sensor 212, any sensor capable of detecting the odor generated by excretion can be used.

The odor detecting unit 2 may have only one of the suction flow paths 22a to 22f, or may have seven or more suction flow paths. Further, the TVOC sensor 211 and / or the nitrogen dioxide sensor 212 may be installed under the sheets by omitting the suction flow path.

In the above embodiment, the suction ports Pa to Pf of the six suction channels 22a to 22f are arranged in a 2 × 3 matrix having two rows in the length direction and three rows in the width direction. However, the present invention is not limited to this, and the number of suction flow paths provided in the odor detection unit 2 and the arrangement of the suction ports are arbitrary, and any number and arrangement suitable for odor detection may be used.

In the physical condition monitoring system 100 of the above embodiment, the predictive motion estimation unit 42 includes the time variation of the measured center of gravity G and / or the time variation of the measured load signals s _{1 to s 4} , and the storage unit 5. Based on the comparison with the reference data stored in advance in the above, it may be estimated that the subject S has performed the defecation signing motion. The reference data includes the locus of the center of gravity as shown in FIGS. 5 (a), 6 (a), and 7 (a), and the reference data as shown in FIGS. 5 (b), 6 (b), and 7 (b). It can be a load signal. In this modification, the predictive motion estimation unit 42 may presume that the subject S has performed a defecation predictive motion when the measured temporal variation matches or resembles the reference data.

In the physical condition monitoring system 100 of the above embodiment, the large body movement trajectory removing unit 431 determines that a large body movement has occurred when the center of gravity G of the subject S moves in substantially one direction within a predetermined time and exceeds a predetermined distance. However, it may be specified that the center of gravity trajectory GT during this period is a large body motion trajectory. Whether or not the center of gravity G is moving in substantially one direction is determined by, for example, whether the angle between the motion vector of the center of gravity G in a predetermined sampling period and the motion vector of the center of gravity G in the next sampling period is equal to or less than a predetermined angle. It can be judged based on whether or not it is.

Specifically, for example, as shown in FIG. 18, the motion vectors v _{52 to v 54} of the center of gravity G have an angle of about 5 ° or less with respect to the motion vector in the sampling period immediately before the motion vector. The motion vector v ₅₅ has an angle of 5 ° or more with respect to the _{motion vector v 54} in the sampling period immediately before the motion vector v 55. In such a case, it can be considered that the center of gravity G moves in a substantially constant direction in the sampling period corresponding to _{the motion vectors v 51 to v 54} , and the moving direction is changed in the sampling period corresponding _{to the motion vector v 55.} can.

When the large body movement trajectory removing unit 431 considers that the movement direction has been changed, the movement vector (here, motion vectors v _{51 to v 54} ) before the time when the movement direction is changed is used for a predetermined time. It is determined whether or not a movement exceeding a predetermined distance has occurred within. Then, when the movement exceeding the predetermined distance occurs within the predetermined time, the locus represented by these motion vectors is specified as a large body motion locus.

The center of gravity locus GT may be filtered by a low-pass filter before specifying a large body movement locus using a motion vector. As a result, high frequency components (noise) are removed, and specific accuracy can be improved.

In the physical condition monitoring system 100 of the above embodiment, the small body movement locus removing unit 432 specifies the small body movement locus by the method of removing outliers, but the present invention is not limited to this. Specifically, for example, even if the respiratory vibration trajectory is specified by specifying the extreme value of the center of gravity trajectory GT, and the center of gravity trajectory GT extending in a direction different from the vibration direction of the respiratory vibration trajectory is specified as a small body motion trajectory. good.

In physical condition monitoring system 100 of the above embodiment, the small body movement locus removing unit 422 and the locus discriminator 433, based on the vibration direction of the breathing vibration locus of the subject S (e.g. direction of the mode vector v _f), the It may function as a body axis direction determining unit that determines that the direction is the extending direction of the body axis of the subject S.

In the physical condition monitoring system 100 of the above embodiment, the locus discrimination unit 433 separates the respiratory vibration locus and the defecation / urination locus based on the amount of linear movement of the position of the center of gravity G. Is not limited. The locus distinguishing unit 433 removes high-frequency components by applying filtering to the load signal corresponding to the center of gravity locus GT received from the small body movement locus removing unit 432, and defecation / urination locus (defecation / urination locus) based on the remaining load component. Defecation and urination component) may be specified.

In this way, frequency filtering can be applied to distinguish between the respiratory vibration trajectory and the defecation / urination trajectory.

In the physical condition monitoring system 100 of the above embodiment, the defecation / urination locus determination unit 43 includes a locus distinguishing unit 433, and the defecation / urination locus is explicitly specified, but the present invention is not limited to this. The defecation / urination trajectory determination unit 43 may determine that the defecation / urination trajectory exists without explicitly specifying the defecation / urination trajectory. Specifically, for example, it is determined that the defecation / urination locus exists based on the fact that the center of gravity locus from which the large body movement locus and the small body movement locus are removed has a spread exceeding a predetermined value in the axial direction. May be good. Since the center of gravity locus from which the large body movement locus and the small body movement locus are removed usually only vibrates in response to breathing, the locus is the amplitude of the breathing vibration locus in the direction of the vibration axis of the breathing vibration. If it shows a relatively large spread exceeding, it is highly possible that there is a stool / urination trajectory.

In the physical condition monitoring system 100 of the above embodiment, the excretion state determination unit 44 determines the excretion state of the subject S according to the flowchart shown in FIG. 16, but the present invention is not limited to this. The excretion state determination unit 44 is the result of the odor detection step S5 by the odor detection unit 2, the result of the predictive motion estimation step S3 by the predictive motion estimation unit 42, and the defecation / urination trajectory determination step S4 by the defecation / urination trajectory determination unit 43. The excretory state of the subject S can be determined by an arbitrary procedure using the results.

Specifically, for example, the excretion state can be determined according to the flowchart of FIG.

In this modification, the excretion state determination unit 44 first determines whether or not odor is generated in the vicinity of the buttocks of the subject S at the determination target time using the result of the odor detection step S5 (S51). When no odor is generated (S51, NO), it is determined that there is no excretion (S57), and the determination result is output to the display unit 6 (S58).

On the other hand, when odor is generated near the buttocks of the subject S (S51, YES), the result of the defecation / urination trajectory determination step S4 is used for a predetermined period immediately before the determination target time (20 to 80 as an example). It is confirmed whether or not the defecation / urination trajectory has occurred in the period of about seconds or the period of about 60 seconds (S52).

When no defecation / urination trajectory has occurred (S52, NO), it is determined that there is flatulence (S56), and the determination result is output to the display unit 6 (S58). On the other hand, when a defecation / urination locus occurs (S52, YES), a predetermined period immediately before the determination target time (for example, a period of about 40 to 80 seconds) using the result of the predictive motion estimation step S3. Or, it is confirmed whether or not the defecation signing motion has occurred in the period of about 60 seconds (S53).

When a defecation sign operation has occurred (S53, YES), it is determined that there is defecation (S54), and the determination result is output to the display unit 6 (S48). When no predictive action has occurred (S53, NO), it is determined that urination is present (S55), and the determination result is output to the display unit 6 (S58).

As another example, the excretion state determination unit 44 sets a predictive motion flag when the subject S estimates that the subject S has performed a defecation predictive motion, and a predetermined period after setting the predictive motion flag ( As an example, when the odor detecting unit 2 detects an odor within about 40 to 80 seconds, or about 60 seconds), it may be determined that the subject S has defecation.

As yet another example, the excretion state determination unit 44 may refer to the detection result of the odor detection unit 2 when the defecation / urination trajectory determination unit 43 specifies the defecation / urination trajectory. In this case, if the odor detecting unit 2 does not detect the odor, it is determined that there is no excretion. On the other hand, when odor is detected, the estimation result of the predictive motion estimation unit 42 is further referred to, and when it is estimated that there is a predictive motion, it is determined that there is defecation, and it is estimated that there is a predictive motion. If not, it is judged that there is urination.

In the physical condition monitoring system 100 of the above embodiment, the defecation / urination locus determination unit 43 may be omitted. Even in such an embodiment, the presence or absence of defecation in the subject S can be determined with high accuracy.

In the physical condition monitoring system 100 of the above embodiment, the predictive motion estimation unit 42 may be omitted. Even in such an embodiment, the presence or absence of defecation or urination of the subject S can be determined with high accuracy.

In the present invention and the present specification, "determination of excretion state" means determination including at least one of determination of presence / absence of excretion, determination of presence / absence of defecation, determination of presence / absence of urination, and determination of presence / absence of flatulence. ..

The physical condition monitoring system 100 of the above embodiment may include a humidity detection unit that detects the humidity on the bed and a temperature detection unit that detects the temperature on the bed. The humidity detection unit may include a plurality of humidity sensors arranged in a matrix under the bed sheets, and the temperature detection unit may include a plurality of temperature sensors arranged in a matrix under the bed sheets.

In the above embodiment, the case where the subject S is wearing a diaper has been described as an example, but even when the subject is not wearing a diaper, the physical condition monitoring system 100 of the above embodiment is used to describe the above embodiment. The excretion state of the subject can be determined by the same principle as above.

The physical condition monitoring system 100 of the above embodiment does not necessarily have to include all of the load detectors 11 to 14, but may have only one of them. Further, the load detectors do not necessarily have to be placed at the four corners of the bed, and may be placed at any position so that the load of the subject on the bed and its fluctuation can be detected. Further, the load detectors 11 to 14 are not limited to the load sensor using the beam type load cell, and for example, a force sensor can also be used.

In physical condition monitoring system 100 of the above embodiment, each of the load detector 11 to 14 is limited to this had been placed under the casters C ₁ -C ₄ attached to the lower end of the leg of the bed BD I can't. Each of the load detectors 11-14 may be provided between the four legs of the bed BD and the floorboard of the bed BD, or if the four legs of the bed BD can be split up and down, the upper part. It may be provided between the leg and the lower leg.

In the physical condition monitoring system 100 of the above embodiment, the load detection unit 1 is configured by a large number of pressure sensors (pressure sensors) arranged in a matrix below the subject lying on the bed, for example, under the sheets. You can also. In this embodiment, the position of the center of gravity of the subject can be determined based on the outputs of a large number of pressure sensors.

The load detection unit 1 and the bed BD may be integrally or detachably combined to form a bed system BDS including the bed BD and the physical condition monitoring system 100 of the above embodiment (FIG. 19).

In the physical condition monitoring system 100 of the above embodiment, the signal from the load detection unit 1 and / or the odor detection unit 2 is amplified between the load detection unit 1 and / or the odor detection unit 2 and the A / D conversion unit 3. A signal amplification unit or a filtering unit that removes noise from the signal may be provided.

In the physical condition monitoring system 100 of the above embodiment, the display unit 6 is a simple device such as a printer that prints and outputs information indicating the excretion state in place of or in addition to the monitor, and a lamp that displays the excretion state. It may be provided with various visual display means. The notification unit 7 may include a vibration generation unit that performs notification by vibration in place of or in addition to the speaker.

As long as the features of the present invention are maintained, the present invention is not limited to the above-described embodiment, and other embodiments considered within the scope of the technical idea of the present invention are also included within the scope of the present invention. ..

According to the physical condition monitoring system of the present invention, it is possible to determine the excretion state of a subject with high accuracy and contribute to the improvement of the quality of medical treatment, long-term care and the like.

1 Load detector, 11, 12, 13, 14 Load detector, 2 Odor detector, 3 A / D conversion unit, 4 Control unit, 41 Center of gravity position calculation unit, 42 Predictive motion estimation unit, 43 Defecation / urination trajectory determination Unit, 44 Excretion status determination unit, 5 Storage unit, 6 Display unit, 7 Notification unit, 8 Input unit, 100 Biological condition monitoring system, BD bed, BDS bed system, S subject

Claims (11)

A physical condition monitoring system that monitors the physical condition of the subject on the bed.
A plurality of load detectors provided on the bed or under the legs of the bed to detect the load of the subject, and
An odor detection unit that detects the odor on the bed, and
A predictive motion estimation unit that estimates the defecation predictive motion of the subject based on the time variation of the detected load of the subject, and the predictive motion estimation unit.
A physical condition monitoring system including an excretion determination unit that determines the presence or absence of defecation by the subject based on the detection result of the odor detection unit and the estimation result of the predictive motion estimation unit. Further, a center of gravity position calculation unit for obtaining a temporal variation of the center of gravity position of the subject based on the detected load is provided.
The physical condition monitoring system according to claim 1, wherein the predictive motion estimation unit estimates the defecation predictive motion of the subject based on the temporal fluctuation of the position of the center of gravity of the subject. A center of gravity position calculation unit that obtains a temporal variation in the center of gravity position of the subject based on the detected load, and a center of gravity position calculation unit.
Based on the movement distance of the center of gravity position that moves within a predetermined time, a large body movement component that fluctuates according to a large body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the center of gravity position is determined. A large body movement component removing unit that removes the large body movement component from the temporal fluctuation of
Based on the moving direction of the center of gravity position, a small body movement component that fluctuates according to a small body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the temporal fluctuation of the center of gravity position is used to determine the small body movement component. Further equipped with a small body movement component removing part that removes small body movement components,
The excretion determination unit is based on the detection result of the odor detection unit, the estimation result of the predictive motion estimation unit, and the temporal fluctuation of the center of gravity position from which the large body movement component and the small body movement component are removed. The physical condition monitoring system according to claim 1, wherein the excretion state of the subject is determined. Defecation of the subject from the temporal variation of the center of gravity position from which the large body motion component and the small body motion component are removed, based on the movement distance of the center of gravity position or the frequency of the temporal variation of the detected load. And / or a defecation urination component specifying part that specifies a defecation urination component that fluctuates according to urination.
According to claim 3, the excretion determination unit determines the excretion state of the subject based on the detection result of the odor detection unit, the estimation result of the predictive motion estimation unit, and the identification result of the defecation / urination component identification unit. Described physical condition monitoring system. The physical condition monitoring system according to claim 3 or 4, wherein the determination of the excretion state includes determination of the presence or absence of excretion and whether the excretion is defecation, urination, or flatulence. The physical condition monitoring system according to any one of claims 3 to 5, wherein the predictive motion estimation unit estimates the defecation predictive motion of the subject based on the temporal fluctuation of the position of the center of gravity of the subject. A physical condition monitoring system that monitors the physical condition of the subject on the bed.
A plurality of load detectors provided on the bed or under the legs of the bed to detect the load of the subject, and
A center of gravity position calculation unit that obtains a temporal variation in the center of gravity position of the subject based on the detected load, and a center of gravity position calculation unit.
Based on the movement distance of the center of gravity position that moves within a predetermined time, a large body movement component that fluctuates according to a large body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the center of gravity position is determined. A large body movement component removing unit that removes the large body movement component from the temporal fluctuation of
Based on the moving direction of the center of gravity position, a small body movement component that fluctuates according to a small body movement different from the breath of the subject is determined from the temporal fluctuation of the center of gravity position, and the temporal fluctuation of the center of gravity position is used to determine the small body movement component. A small body movement component removing part that removes small body movement components,
An odor detection unit that detects the odor on the bed, and
A body including an excretion determination unit that determines the excretion state of the subject based on the temporal fluctuation of the position of the center of gravity from which the large body movement component and the small body movement component are removed and the detection result of the odor detection unit. Status monitoring system. Defecation of the subject from the temporal variation of the center of gravity position from which the large body motion component and the small body motion component are removed, based on the movement distance of the center of gravity position or the frequency of the temporal variation of the detected load. And / or a defecation urination component specifying part that specifies a defecation urination component that fluctuates according to urination.
The physical condition monitoring system according to claim 7, wherein the excretion determination unit determines the excretion state of the subject based on the specific result of the defecation / urination component identification unit and the detection result of the odor detection unit. The physical condition monitoring system according to any one of claims 1 to 8, wherein the odor detecting unit is a total volatile organic compound (TVOC) sensor and / or a nitrogen dioxide sensor. The physical condition according to any one of claims 1 to 9, wherein the plurality of load detectors are four load detectors, each of which is installed under four legs provided at four corners of the bed. Monitoring system. Bed and
A bed system including the physical condition monitoring system according to any one of claims 1 to 10.

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