Urine accumulation degree estimation system, urine accumulation degree estimation program, and urine accumulation degree estimation device

Abstract

Provided is a system that more accurately estimates the degree of urine accumulation by solving a problem in which the influence of a change in the amount of urine accumulation is obscured when the biological impedance in the vicinity of the bladder is affected as the muscles contract. This urine accumulation degree estimation system (2) comprises: a measurement means for measuring at least two types of biological impedance by energizing a bladder (60) at at least two different frequencies; and an estimation means that estimates the urine accumulation degree of the bladder (60) on the basis of the at least two types of biological impedance. The at least two frequencies include a frequency at which the bladder (60) and the muscles (66) around the bladder can be energized, and a frequency at which the muscles (66) around the bladder can be energized.

Description

Urinary retention degree estimation system, urinary retention degree estimation program, and urinary retention degree estimation device Cross-reference to related applications

[0001] In this application, the benefit of Patent Application No. 2024-191855 filed in Japan on October 31, 2024 is claimed, and the content of the said application is incorporated herein by reference.

[0002] The present technology relates to a urinary retention degree estimation system, a urinary retention degree estimation program, and a urinary retention degree estimation device that estimate the urinary retention degree based on the bioimpedance of the subject.

[0003] At care facilities and medical institutions, assisting the urination of care recipients and patients is one of the important issues related to maintaining QOL (Quality Of Life). Among care recipients and patients, there are those who have difficulty perceiving the urge to urinate despite maintaining bladder function, those who need assistance with the urination operation but have difficulty communicating the urge to urinate to caregivers, etc.

[0004] Conventionally, there has been known a technique for estimating the urine volume by measuring the bioimpedance of the bladder and providing urination support by utilizing the principle of the bioimpedance method that an electric current passes through fat-free tissue containing moisture and electrolytes while not passing through fat tissue that does not contain moisture (for example, Japanese Patent Laid-Open No. 63-252138 and International Publication No. 2016 / 177901).

[0005] Japanese Patent Laid-Open No. 63-252138 describes a device that notifies a third party of the urge to urinate by generating an alert when it is determined that the urine storage state has reached a certain level based on the change in bioimpedance measured near the bladder.

[0006] International Publication No. 2016 / 177901 describes a system for measuring urine flowing from the kidney to the bladder using bioimpedance technology, and displays the change in the urine volume in the bladder by analyzing the difference between impedance measurement values collected in the bladder for a certain period. Summary

[0007] The technologies disclosed in the above-mentioned patent documents estimate the amount of urine stored in the subject or its changes based on bioelectrical impedance. However, muscle contractions caused by body movements or posture during measurement can mask the effect of changes in urine storage volume on bioelectrical impedance, making it difficult to accurately estimate the amount of urine stored or its changes. While it is possible to detect body movements by attaching an accelerometer to the subject, the amount of change in bioelectrical impedance due to body movements varies depending on the type of movement and the subject's muscle mass. Therefore, it is difficult to accurately detect the effect of muscle contraction on bioelectrical impedance using only information obtained from the accelerometer. Furthermore, muscle contractions that do not involve movement, such as when tensing the abdominal muscles, cannot be detected by an accelerometer in the first place.

[0008] Therefore, the aim of this technology is to provide a urine storage capacity estimation system, a urine storage capacity estimation program, and a urine storage capacity estimation device that can estimate the urine storage capacity of a subject by reducing the influence of muscle contraction caused by body movements and posture during measurement.

[0009] (1) A urine storage capacity estimation system according to one aspect of the present technology comprises measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and estimation means for estimating the urine storage capacity of the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the bladder and surrounding muscles, and a frequency that can be applied to the surrounding muscles.

[0010] This configuration reduces the influence of muscle contractions around the bladder, allowing for accurate estimation of urine storage capacity.

[0011] (2) In the urine storage capacity estimation system of (1), the estimation means may use the estimated urine storage capacity based on the at least two types of bioelectrical impedance when the amount of urine stored is small relative to the capacity of the subject's bladder as a reference value, and estimate the urine storage capacity of the subject by comparing the reference value with the estimated urine storage capacity based on the at least two types of bioelectrical impedance measured by the measurement means.

[0012] This configuration allows for the relative estimation of urine storage capacity by using impedance measured as a relative value corresponding to a reference value for each user being measured. Typically, a low urine storage volume relative to bladder capacity occurs immediately after urination.

[0013] (3) The urine storage level estimation system of (1) or (2) may further include notification means for notifying when the urine storage level exceeds a predetermined threshold.

[0014] This configuration allows caregivers to respond to notifications, such as providing assistance with urination.

[0015] (4) In the urine storage level estimation system of (3), the threshold may be variable.

[0016] This configuration allows for changing thresholds according to each user's urination control ability, care environment, and other factors.

[0017] (5) In any of the urine storage capacity estimation systems of (1) to (4), the measuring means may measure at least two types of bioimpedances: a first bioimpedance measured by passing a high-frequency current that can be passed through the bladder and surrounding muscles, and a second bioimpedance measured by passing a low-frequency current that can be passed through the surrounding muscles. The estimation means may then estimate the urine storage capacity by correcting the value of the first bioimpedance using the value of the second bioimpedance to calculate the estimated urine storage capacity.

[0018] This configuration allows for accurate estimation of urine volume by using high-frequency and low-frequency currents to measure impedance, thereby reducing the influence of changes in bioimpedance caused by muscle contraction.

[0019] (6) In the urine storage capacity estimation system of (5), the estimation means may calculate the estimated urine storage capacity by dividing the second bioimpedance by the first bioimpedance.

[0020] With this configuration, the ratio of the second bioimpedance to the first bioimpedance is obtained as a highly accurate estimated urine volume with reduced influence from changes in bioimpedance due to muscle contraction.

[0021] (7) A urine storage capacity estimation program in one aspect of the present technology has a computer functioning as a measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and an estimation means for estimating the urine storage capacity of the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the muscles of the bladder and surrounding muscles, and a frequency that can be applied to the muscles surrounding the bladder.

[0022] This configuration also reduces the influence of muscle contractions around the bladder, allowing for accurate estimation of urine storage capacity.

[0023] (8) A urine storage capacity estimation device according to one aspect of the present technology comprises measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and estimation means for estimating the urine storage capacity of the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the bladder and surrounding muscles, and a frequency that can be applied to the surrounding muscles.

[0024] This configuration also reduces the influence of muscle contractions around the bladder, allowing for accurate estimation of urine storage capacity.

[0025] This technology allows for the estimation of bladder capacity by reducing the influence of muscle contractions around the bladder.

[0026] Figure 1 is a schematic diagram of the urine storage capacity estimation system according to an embodiment of this technology. Figure 2 is a functional block diagram of the urine storage capacity estimation system according to an embodiment of this technology. Figure 3 is a schematic representation of the tissues through which high-frequency and low-frequency currents are conducted. Figure 4a is a graph showing examples of the time changes of low-frequency bioimpedance and high-frequency bioimpedance, respectively, when there is no muscle contraction, and a graph showing an example of the time change of the ratio of high-frequency bioimpedance to low-frequency bioimpedance, according to an embodiment of this technology. Figure 4b is a graph showing examples of the time changes of low-frequency bioimpedance and high-frequency bioimpedance, respectively, when there is muscle contraction, and a graph showing an example of the time change of the ratio of high-frequency bioimpedance to low-frequency bioimpedance, according to an embodiment of this technology. Figure 5 is a flowchart showing the flow of the urine storage capacity estimation process according to the embodiment.

[0027] The embodiments of this technology will be described below with reference to the drawings. The embodiments described below are merely examples of how this technology can be implemented, and the technology is not limited to the specific configurations described below. In implementing this technology, specific configurations may be adopted as appropriate depending on the embodiment.

[0028] Furthermore, in this application, the person whose urine storage capacity is estimated using the urine storage capacity estimation system is referred to as the "person being measured" or the "user" (of the urine storage capacity estimation device), and the person who manages or assists the person's urination using the urine storage capacity estimation system is referred to as the "user" or "caregiver." Here, the "person being measured" or "user" may also be the "user" or "caregiver" who manages their own urination using the urine storage capacity estimation system.

[0029] Figure 1 is a schematic diagram of the urine storage capacity estimation system according to an embodiment of this technology. The urine storage capacity estimation system 2 comprises a urine storage capacity estimation device 4 and a terminal device 10. Note that the sizes of each device in Figure 1 do not reflect their actual sizes. As shown in Figure 1, the urine storage capacity estimation device 4 is worn by the person being measured and estimates the person's urine storage capacity, and the terminal device 10 notifies the person that it is time to urinate in accordance with the urine storage capacity estimation device 4. If the person being measured needs assistance with urination, the terminal device 10 may be held by the caregiver. If the person being measured has difficulty recognizing the urge to urinate but can urinate on their own, the terminal device 10 may be held by the person being measured. Furthermore, one terminal device 10 may be provided for multiple urine storage capacity estimation devices 4 in order to manage the urination of multiple people.

[0030] The urine storage capacity estimation device 4 estimates the urine storage capacity of the subject by applying an electric current to the subject's bladder 60 and measuring the bioimpedance, which is the electrical resistance. When urine, a body fluid with relatively high conductivity, is stored in the bladder 60, the bioimpedance value near the bladder 60 is lower than when there is no urine in the bladder 60. When there is no urine in the bladder 60, the bioimpedance value is relatively high. The urine storage capacity estimation device 4 uses this principle to estimate the urine storage capacity of the subject.

[0031] The urine volume estimation device 4 comprises a holder 6, a calculation control device 8, two current application electrodes 16, and two voltage detection electrodes 18. The holder 6 holds the calculation control device 8, the current application electrodes 16, and the voltage detection electrodes 18, and fixes the current application electrodes 16 and the voltage detection electrodes 18 to the skin near the wearer's bladder 60. Specifically, as shown in Figure 1, the holder 6 is a belt type and is attached by wrapping it around the lower abdomen of the person being measured, holding the calculation control device 8, the current application electrodes 16, and the voltage detection electrodes 18. The holder 6 is not limited to a belt type and may be attached to the person being measured in the form of underwear, a band, a belly band, etc. The method of attaching the holder 6 to the person being measured may be selected according to the wearer's physical function and lifestyle. It is desirable that the holder 6 be made of an elastic material.

[0032] The calculation control unit 8 is connected to the current application electrode 16 and the voltage detection electrode 18 by cables. The current application electrode 16 and the voltage detection electrode 18 are held in the holder 6 in a position that contacts the skin around the bladder 60 when the person being measured wears the holder 6.

[0033] To measure the bioelectrical impedance near the bladder 60, it is desirable that the current application electrode 16 be in contact with the inside of the subject's hip bone, and that the voltage detection electrode 18 be in contact with any position near the pubic symphysis on the anterior part of the bladder 60. The current application electrode 16 and the voltage detection electrode 18 are held in a position that contacts the above positions when the holder 6 is attached to the subject. Since the bladder 60 is located posterior to the pubic symphysis on the midline of the lower abdomen in both men and women, the arrangement of the electrodes may be the same for both sexes.

[0034] The calculation control device 8 measures the bioimpedance near the bladder 60 of the person being measured by applying a weak current to the body through the current application electrode 16 and detecting the voltage with the voltage detection electrode 18. The current application electrode 16 and the voltage detection electrode 18 are made of metal, but are not limited to metal; they may be made of any conductive material, such as gel, rubber, or fibrous material.

[0035] The arithmetic control unit 8 functions as a device that calculates bioimpedance based on the voltage difference detected using the current application electrode 16 and the voltage detection electrode 18, and estimates the urine storage capacity of the subject from the calculated bioimpedance. Furthermore, the arithmetic control unit 8 functions as a device that determines the timing of urination based on the estimated urine storage capacity. The arithmetic control unit 8 also has the function of communicating with the terminal device 10.

[0036] The terminal device 10 is, for example, a smartphone as shown in Figure 1, but is not limited to this; it may also be a portable information processing device such as a laptop-type personal computer with a monitor or a tablet terminal. Furthermore, it may not be a general-purpose information processing device such as a smartphone, but a dedicated device. The terminal device 10 can accept input of various setting values ​​and display estimation and judgment results, etc. Here, as an example, an embodiment in which the terminal device 10 such as a smartphone provides notification by screen display is described, but the means of notification are not limited to this; any means that appeals to human perception may be used, such as emitting sound from an audio converter or turning on a light source.

[0037] Furthermore, in order to improve the accuracy of urine volume estimation, the terminal device 10 may receive measurement data or estimated data from multiple urine volume estimation devices 4 within the nursing care facility. In addition, by connecting to the Internet (not shown), it may be possible to receive measurement data from one or more people outside the facility (including or not including the person being measured) or statistical data thereof from an external server device. Data transmission and reception may be performed by wireless short-range communication such as Bluetooth or Wi-Fi, or by wired communication via Ethernet. These various types of data can be stored in the terminal device 10 or the server device.

[0038] Figure 2 is a functional block diagram of the urine storage level estimation system 2 of this embodiment. The calculation control device 8 of the urine storage level estimation device 4 includes a frequency setting unit 12, a current application control unit 14, a bioimpedance calculation unit 20, a urine volume estimation unit 22, a urine storage level estimation unit 24, a notification determination unit 26, a storage unit 28, and a communication unit 30. Each function performed by each unit shown in Figure 2 may, for example, be executed by the urine storage level estimation program of this embodiment in the calculation control device 8, or it may be realized by a logic circuit without using a program.

[0039] The terminal device 10 includes a communication unit 42, a notification unit 44, and a storage unit 46 in order to notify the user of the urine storage level of the subject. Similar to the arithmetic control device 8, each function executed by each unit may be executed by the terminal device 10 by a program as an example, or may be realized by a logic circuit without using a program.

[0040] First, the measurement of the bioimpedance by the urine storage level estimation device 4 will be described. The frequency setting unit 12 sets the frequency of the current flowing through the current application electrode 16 (hereinafter referred to as "current frequency"). The current frequency in the present embodiment can be arbitrarily set within a predetermined frequency range. As an example, in the frequency setting unit 12, a frequency of 50 kHz or less that does not pass through adipose tissue is set as the low frequency, and a frequency of 250 kHz or more that passes through adipose tissue is set as the high frequency.

[0041] FIG. 3 is a diagram schematically showing tissues through which high-frequency current and low-frequency current are passed. Referring to FIG. 3, the reason for measuring two types of bioimpedance using two types of currents, i.e., a high-frequency current 64 and a low-frequency current 62, will be described. As shown in FIG. 3, the bladder 60 is covered with a tissue called the bladder wall. The bladder wall is a tissue composed of an adipose layer, a muscular layer, and a mucosa in this order toward the inside of the bladder 60. The periphery of the bladder 60 is surrounded by muscles 66.

[0042] When a current is applied from the current application electrode 16 disposed on the skin near the bladder 60, as described above, the tissues through which the low-frequency current 62 and the high-frequency current 64 pass are different. The low-frequency current 62 can pass through the muscles 66 around the bladder 60, but does not pass through the adipose layer of the bladder wall. Therefore, the low-frequency current 62 does not pass through tissues such as the muscular layer and mucosa in the inner direction, and the bioimpedance hardly reflects the amount of urine stored inside the bladder.

[0043] On the other hand, since the high-frequency current 64 passes through the adipose layer of the bladder wall, it can pass through not only the muscles 66 around the bladder 60 but also tissues such as the muscular layer and mucosa inside the bladder wall, and the bioimpedance is likely to reflect the amount of urine stored inside the bladder 60.

[0044] As mentioned above, it is known that the measured bioimpedance is affected by the contraction of the muscles 66 around the bladder 60, that is, by body movements and posture during measurement. One reason for this is that muscle contraction occurs due to body movements and posture during measurement, that is, changes occur in the cross-sectional area of ​​the muscles. In this embodiment, the bioimpedance measured by a high-frequency current 64, that is, the bioimpedance measured by a low-frequency current 62, that is, the bioimpedance measured by a low-frequency current 62, that is, the bioimpedance measured by a low-frequency current 62, that is, the bioimpedance measured by a low-frequency current 62, that is, the bioimpedance measured by a low-frequency current 64

[0045] Therefore, the urine storage volume estimation device 4 measures two types of bioimpedances around the bladder 60 using currents of two different frequencies and subjects them to the estimation process described later, thereby reducing the influence of muscle contraction 66 around the bladder 60 and estimating the amount of urine stored inside the bladder 60.

[0046] The current application control unit 14 controls the on / off state of the current, which is set in the frequency setting unit 12 to switch between a high-frequency current 64 and a low-frequency current 62. When the current is turned on, current flows from the current application electrode 16, which is in contact with the person being measured, towards the wearer's bladder 60. Since the urine volume estimation device 4 is intended to be worn at all times, for example, the current may be automatically turned on and off at regular intervals by a timer or clock (not shown) provided in the urine volume estimation device 4. Since the switching between the high-frequency current 64 and the low-frequency current 62 is performed in a very short time, the bioimpedance calculated for each frequency in the calculation process described later can be considered as values ​​measured at the same time.

[0047] The voltage detection electrode 18 detects the voltage generated by flowing a current through the current application electrode 16. As shown in FIG. 1, the urine storage amount estimation device 4 has two current application electrodes 16 and two voltage detection electrodes 18. The current application control unit 14 may control the two current application electrodes 16 and the two voltage detection electrodes 18 so that a current is alternately passed through the two current application electrodes 16 and voltages are alternately detected at the two voltage detection electrodes 18 in correspondence with the application of the current from the corresponding current application electrode 16.

[0048] The biological impedance calculation unit 20 calculates the biological impedance near the bladder 60, which is the electrical resistance between the current application electrode 16 and the voltage detection electrode 18 that contact the skin near the bladder 60 of the subject, based on the voltage detected by the voltage detection electrode 18. The biological impedance is calculated for each frequency for use in the correction process described later.

[0049] The urine storage amount estimation unit 22 estimates the urine storage amount in the bladder 60 based on the two types of biological impedances calculated by the biological impedance calculation unit 20. Here, the urine storage amount estimation unit 22 does not obtain the actual volume, weight, or other magnitudes of the urine stored in the bladder 60 as the urine storage amount, but obtains a variable that reflects the amount of urine stored in the bladder 60. In particular, the urine storage amount estimation unit 22 reduces the influence of the contraction of the muscle 66 around the bladder 60 of the subject by performing the following estimation process based on the biological impedance measured by the high-frequency current 64 (hereinafter referred to as "high-frequency biological impedance") and the biological impedance measured by the low-frequency current 62 (hereinafter referred to as "low-frequency biological impedance"), and estimates the urine storage amount.

[0050] The urine storage amount estimation unit 22 estimates, as the urine storage amount, the reciprocal of the ratio of the high-frequency biological impedance to the low-frequency biological impedance (hereinafter referred to as "impedance ratio"), that is, the reciprocal of (high-frequency biological impedance) / (low-frequency biological impedance). The urine storage amount estimation unit 22 may also estimate the urine storage amount using a regression equation with the impedance ratio as an explanatory variable and the urine storage amount as an objective variable. Hereinafter, an explanation will be given of the fact that the impedance ratio reflects the urine storage amount.

[0051] As described above, high-frequency current passes through the muscles and fat outside the bladder, then through the inside of the bladder, and then back through the muscles and fat outside the bladder again. Therefore, high-frequency bioimpedance reflects the effects of muscle contraction and the amount of urine in the bladder. In contrast, low-frequency bioimpedance passes through the muscles and fat outside the bladder but not through the inside of the bladder. Therefore, it reflects the effects of muscle contraction but does not reflect the effects of the amount of urine in the bladder or the amount of urine stored. Note that a state without muscle contraction is defined as the state in which the subject is stationary with the holder 6 attached (initial state). In a stationary state, the subject may be sitting or standing.

[0052] The upper left graph in Figure 4a shows an example of the time change of high-frequency bioimpedance when there is no muscle contraction during the measurement period, and the lower left graph in Figure 4a shows an example of the time change of low-frequency bioimpedance when there is no muscle contraction during the measurement period. As these graphs show, when there is no muscle contraction, the value of low-frequency bioimpedance does not change in the lower left graph which shows the effect of muscle contraction, and the value of high-frequency bioimpedance decreases with increasing urine volume, as shown in the upper left graph.

[0053] The upper left graph in Figure 4b shows an example of the time change of high-frequency bioimpedance when muscle contraction occurs during the measurement period, and the lower left graph in Figure 4b shows an example of the time change of low-frequency bioimpedance when muscle contraction occurs during the measurement period. As these graphs show, when muscle contraction occurs, the value of low-frequency bioimpedance in the lower left graph, which shows the effect of muscle contraction, fluctuates up and down in accordance with changes in muscle contraction and relaxation, while the value of high-frequency bioimpedance, as shown in the upper left graph, decreases with increasing urine volume and also fluctuates up and down in accordance with changes in muscle contraction and relaxation. In other words, the value of high-frequency bioimpedance is superimposed with the decrease due to increased urine volume and the fluctuations due to muscle contraction and relaxation.

[0054] Therefore, the urine volume estimation unit 22 calculates the ratio of high-frequency bioimpedance to low-frequency bioimpedance in order to remove fluctuations due to muscle contraction, etc., from the change in high-frequency bioimpedance shown in the graph in the upper left of Figure 4a, and uses the impedance ratio obtained in this way as the estimated urine volume. In other words, the urine volume estimation unit 22 corrects the high-frequency bioimpedance, which is a variable that reflects the urine volume of the bladder and muscle contraction, with the low-frequency bioimpedance, which is a variable that reflects muscle contraction, to obtain a variable that reflects only the urine volume of the bladder, and uses this as the estimated urine volume.

[0055] As a result, the urine volume estimation unit 22 can estimate the amount of urine stored in the bladder, excluding the effects of muscle contraction, as shown in the graph on the right of Figure 4b. Comparing the graph on the right of Figure 4a with the graph on the right of Figure 4b, the same impedance ratio is obtained even when there is muscle contraction (Figure 4b) as when there is no muscle contraction (Figure 4a). This indicates that the impedance ratio is not affected by muscle contraction and that (its reciprocal) reflects the amount of urine stored in the bladder.

[0056] In the examples in Figures 4a and 4b, for the sake of explanation, we described an example where low-frequency bioimpedance fluctuates only due to changes in muscle contraction and relaxation, and where the fluctuations due to changes in muscle contraction and relaxation can be completely removed from high-frequency bioimpedance by dividing it by low-frequency bioimpedance. However, in reality, low-frequency bioimpedance can fluctuate due to factors other than changes in muscle contraction and relaxation, and fluctuations in high-frequency bioimpedance due to changes in muscle contraction and relaxation do not necessarily directly translate to fluctuations in low-frequency bioimpedance. Therefore, while dividing high-frequency bioimpedance by low-frequency bioimpedance does not completely eliminate the effects of changes in muscle contraction and relaxation, it certainly reduces those effects.

[0057] In this embodiment, the urine volume estimation unit 22 estimates the urine volume by reducing the effect of muscle contraction and relaxation superimposed on the high-frequency impedance by dividing the high-frequency bioimpedance by the low-frequency bioimpedance. However, the method for reducing the effect of muscle contraction and relaxation superimposed on the high-frequency impedance is not limited to this. For example, the urine volume estimation unit 22 may calculate an estimated urine volume with the effect of muscle contraction and relaxation superimposed on the high-frequency impedance reduced by subtracting a constant multiple of the low-frequency bioimpedance from the value of the high-frequency bioimpedance.

[0058] In other words, the urine volume estimation unit 22 may estimate the urine volume by obtaining a variable that reflects only the amount of urine stored in the bladder, by using the values ​​processed under predetermined conditions to determine the difference between high-frequency bioimpedance and low-frequency bioimpedance (hereinafter referred to as "impedance difference"). Here, although not shown in the figures, similar impedance differences can be obtained for both the case with and without muscle contraction, just as with the impedance ratio. Therefore, the impedance difference can also be used as a value that reflects the amount of urine stored in the bladder, without being affected by muscle contraction (its reciprocal).

[0059] The urine storage degree estimation unit 24 estimates the degree of urine storage, which indicates the degree of urine storage in the subject's bladder 60, based on the estimated urine storage volume obtained by the urine storage volume estimation unit 22. The urine storage degree estimation unit 24 can also use the estimated urine storage volume obtained by the urine storage volume estimation unit 22 as the urine storage degree, but in this embodiment, the urine storage degree is estimated based on the estimated urine storage volume obtained by the urine storage volume estimation unit 22 as follows.

[0060] The urine storage level estimation unit 24 estimates the urine storage level for a subject by comparing the estimated urine storage level obtained when the urine storage volume is low with the estimated urine storage volume obtained at the time of measurement, using the estimated urine storage volume obtained when the urine storage volume is low as a reference value. The estimated urine storage volume obtained when the urine storage volume is low is typically the estimated urine storage volume estimated by measuring bioimpedance immediately after urination, and is hereinafter referred to as the "estimated urine storage volume after urination." The estimated urine storage volume estimated by measuring bioimpedance when monitoring the urine storage level is hereinafter referred to as the "estimated urine storage volume at monitoring." Note that the reference value used for comparison with the estimated urine storage volume obtained at the time of measurement is not limited to the estimated urine storage volume obtained when the urine storage volume is low, but may be the estimated urine storage volume obtained from the bioimpedance measurement immediately before the measurement for the same subject. In this case, the cumulative value of the difference between the estimated urine storage volume obtained from the bioimpedance measurement immediately before the measurement and the estimated urine storage volume obtained at the time of measurement is estimated to be the estimated urine storage volume at monitoring. Note that the notification determination unit 26 may provide notification if the difference with the bioimpedance obtained in the immediately before measurement is greater than or equal to a threshold for high-frequency impedance or low-frequency impedance. Alternatively, the notification determination unit 26 may issue a notification if the difference between the estimated urine volume and the estimated urine volume obtained from the measurement of the bioimpedance immediately prior to the measurement is greater than or equal to a predetermined threshold.

[0061] The urine storage level estimation unit 24 may estimate the urine storage level as the magnitude of the change in the estimated urine storage volume during monitoring relative to the standard value, which is the estimated urine storage volume after urination. Specifically, the urine storage level estimation unit 24 estimates the urine storage level as the ratio of the estimated urine storage volume during monitoring to the standard value, which is the estimated urine storage volume after urination. Alternatively, the urine storage level estimation unit 24 may estimate the urine storage level by subtracting the standard value, which is the estimated urine storage volume after urination, from the estimated urine storage volume during monitoring.

[0062] The notification determination unit 26 provides notification to encourage urination according to the urine storage level estimated by the urine storage level estimation unit 24. Specifically, the notification determination unit 26 determines that it is time for the wearer to urinate when the urine storage level estimated by the urine storage level estimation unit 24 exceeds a predetermined threshold, and outputs a notification signal. Alternatively, the notification determination unit 26 may determine that it is time for the wearer to urinate when the estimated urine storage volume obtained by the urine storage volume estimation unit 22 changes the predetermined threshold, and output a notification signal.

[0063] The threshold value for which the notification determination unit 26 makes a notification determination is variable. The threshold value for notification determination may be changed by receiving an operation for threshold change via an operation unit provided on the urine collection level estimation device 4, but in this embodiment, the threshold value is changed by receiving a command to change the threshold value from the terminal device 10.

[0064] The memory unit 28 is, for example, a non-volatile memory, which is a non-temporary storage medium, and stores various data and programs used for the various calculation processes described above. The memory unit 28 stores data used for the calculation processes, such as the estimated urine volume after urination as a reference value, low-frequency bioimpedance in a state without muscle contraction, and thresholds for notification determination. The memory unit 28, as a non-temporary storage medium, may be portable.

[0065] The communication unit 30 transmits and receives data with the terminal device 10 and other devices. In particular, as described above, when the notification determination unit 26 determines to issue a notification, the communication unit 30 transmits a notification signal to the terminal device 10. The communication unit 30 further transmits to the terminal device 10 data obtained from the above calculation processes, such as the bioimpedance calculated in the bioimpedance calculation process, the estimated urine volume obtained in the urine volume estimation process, the urine volume estimation process, and the determination result of the notification determination unit 26.

[0066] The communication unit 42 of the terminal device 10 transmits and receives data with the calculation control unit 8 of the urine volume estimation device 4. In particular, the communication unit 42 receives notification signals transmitted from the calculation control unit 8 and also receives data obtained by calculation processing transmitted from the calculation control unit 8.

[0067] The notification unit 44, in response to the notification signal received by the communication unit 42, notifies the user of the terminal device 10 in a manner perceptible to the user that the estimated urine storage level has exceeded a predetermined threshold, i.e., that it is time to urinate. Specifically, the notification unit 44 is equipped with a display device and outputs a display indicating that it is time to urinate. In this case, the display screen may be determined according to a program stored in the storage unit 46. The notification unit 44 is equipped with an audio output device and may output a sound, either voice or buzzer, to indicate that it is time to urinate. Furthermore, the notification unit 44 is equipped with a vibration device and may notify the user of the time to urinate by vibration.

[0068] The memory unit 46 is, for example, a non-volatile memory, and stores various data, programs used for various processes, and the results of the determination made by the notification determination unit 26.

[0069] By estimating the amount of urine stored in the wearer's bladder 60 using the urine storage capacity estimation system 2, the timing of urination for a subject who is unable to recognize the urge to urinate or communicate the urge to urinate to a caregiver is notified, allowing the user and caregiver to be aware of this. This notification enables caregivers to provide urination assistance at the appropriate time for subjects who require it. Furthermore, even if the subject is unable to recognize the urge to urinate, the subject or their caregiver can be informed of the subject's urination timing. Therefore, this system improves the efficiency of caregiver assistance and reduces the risk of urination failure for the subject, thus maintaining a higher quality of life (QOL).

[0070] Figure 5 is a flowchart showing the flow of the urine storage level estimation process performed by the urine storage level estimation system 2.

[0071] First, the person being measured puts on the urine volume estimation device 4 (step S100). The urine volume estimation device 4 receives a threshold for notification determination transmitted from the terminal device 10 in the communication unit 30 (step S101). The urine volume estimation device 4 detects the potential difference of the current applied at each frequency by the current application electrode 16 with the voltage detection electrode 18, and measures the bioimpedance by processing the detection result in the bioimpedance calculation unit 20 of the calculation control device 8 (step S102).

[0072] The urine volume estimation unit 22 estimates the amount of urine stored in the subject's bladder 60 based on the high-frequency and low-frequency bioimpedances calculated by the bioimpedance calculation unit 20 (step S104). At this time, the urine volume estimation unit 22 reduces the influence of muscle contraction by correcting the high-frequency bioimpedance value using the low-frequency bioimpedance value, thereby eliminating the influence of muscle contraction and estimating the amount of urine stored.

[0073] The urine storage level estimation unit 24 estimates the urine storage level of the subject's bladder 60 based on the estimated urine storage volume obtained by the urine storage volume estimation unit 22 (step S106). In this case, the urine storage level estimation unit 24 estimates the urine storage level by comparing the urine storage volume measured after urination and the estimated urine storage volume during monitoring, which are stored in the memory unit 28.

[0074] The notification determination unit 26 determines whether the urine storage level estimated by the urine storage level estimation unit 24 has reached a predetermined threshold (step S108). If the urine storage level is below the threshold (NO in step S108), the process returns to step S102, and the high-frequency bioimpedance and low-frequency bioimpedance are calculated again using the current application electrode 16, voltage detection electrode 18, and bioimpedance calculation unit 20.

[0075] If the urine storage level reaches a threshold (YES in step S108), the notification determination unit 26 generates a notification signal indicating that the urine storage level determined by the urine storage level estimation unit 24 has reached a predetermined threshold, and transmits it from the communication unit 30 of the calculation control device 8 to the communication unit 42 of the terminal device 10 (step S110).

[0076] On the terminal device 10 side, the caregiver connects the terminal device 10 to the urine collection level estimation device 4 (step S112). The caregiver or the person holding the terminal device 10 sets a threshold by inputting an arbitrary threshold to the terminal device 10 (step S114). The communication unit 42 transmits the input threshold to the urine collection level estimation device 4 via the communication unit 42 (step S115).

[0077] Furthermore, when the terminal device 10 receives a notification signal transmitted from the arithmetic control unit 8 in step S110 (step S116), the notification unit 44 notifies the user of the terminal device 10 that it is time to urinate in a manner that the user can perceive (step S118).

[0078] Although the present technology has been described above using the embodiments described above, the technical scope of the present technology is not limited to the scope described in the embodiments. Various modifications or improvements can be made to the embodiments without departing from the gist of the present technology, and such modified or improved forms may also be included in the technical scope of the present technology in accordance with the claims.

[0079] A modified embodiment of this technology will now be described. First, the urine storage capacity estimation unit 24 may have the function of estimating body composition values, including muscle fiber density and muscle mass around the bladder 60, using the bioelectrical impedance measurements taken by the urine storage capacity estimation device 4, and user information such as the age, sex, height, and body type of the person being measured. With such body composition values, it is possible to obtain an index that allows for the confirmation of changes over time, for example, regarding the results of continuous muscle training around the bladder 60 performed by the person being measured, and whether the urination control ability of each person has improved.

[0080] Furthermore, the urine storage capacity estimation device 4 may also be equipped with a urination completion indicator unit having a urination completion button. When the person being measured has completed urination, they can press the button themselves, allowing the calculation control device 8 to calculate the bioimpedance immediately after urination and estimate the amount of urine stored immediately after urination. This amount of urine stored immediately after urination can then be used as a reference value for estimating the urine storage capacity. In addition, this modification allows for the accumulation of bioimpedance measurement data from the person being measured, which can contribute to improving the accuracy of subsequent urine storage capacity estimations.

[0081] In the above embodiment, the urine volume estimation unit 22, the urine storage degree estimation unit 24, and the notification determination unit 26 were implemented in the calculation control device 8 of the urine storage degree estimation device 4. However, some or all of the urine volume estimation unit 22, the urine storage degree estimation unit 24, and the notification determination unit 26 may be located in the terminal device 10. In this case, the bioimpedance calculated by the bioimpedance calculation process and the urine volume estimated by the urine volume estimation unit 22 may be transmitted to the terminal device 10.

[0082] In the above embodiment, the notification unit 44 was provided on a terminal device 10, which is a separate device from the urine volume estimation device 4 worn on the person being measured. However, the notification unit 44 may also be located on the urine volume estimation device 4. In this case, the notification unit 44 may be a device that outputs a buzzer sound. The buzzer sound notifies the person being measured or a caregiver nearby of the timing of urination. Furthermore, the terminal device 10 having the notification unit 44 may not be a portable device, but a stationary device that can notify multiple caregivers. For example, a device installed in a nurse's station may be a device that outputs a buzzer sound, and the buzzer sound notifies multiple caregivers present in the nurse's station of the timing of urination.

[0083] In the above embodiment, historical information such as the estimated urine volume, urine storage level, and notification judgment result obtained by the calculation control device 8 was stored in the terminal device 10. However, in addition to this, or instead, this historical information may be stored in a device other than the terminal device 10, and in particular, it may be stored in a cloud-based storage device. By analyzing and evaluating the changes in the historical information over time, the effectiveness of bladder training can be measured.

[0084] The notification determination unit 26 does not have to use a threshold to make a notification determination. For example, the urine storage level estimated by the urine storage level estimation unit 24 may be transmitted to the terminal device 10, and the terminal device 10 may output the change over time. In this case, the caregiver may, based on the urine storage level displayed on the terminal device 10, make their own judgment and assist the person being measured with urination.

[0085] 2 Urine storage volume estimation system 4 Urine storage volume estimation device 6 Holder 8 Calculation control device 10 Terminal device 12 Frequency setting unit 14 Current application control unit 16 Current application electrode 18 Voltage detection electrode 20 Bioimpedance calculation unit 22 Urine storage volume estimation unit 24 Urine storage volume estimation unit 26 Notification judgment unit 28 Memory unit 30 Communication unit 42 Communication unit 44 Notification unit 46 Memory unit 60 Bladder 62 Low frequency current 64 High frequency current 66 Muscles around the bladder

Claims

1. A urine storage capacity estimation system comprising: measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and estimation means for estimating the urine storage capacity of the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the bladder and surrounding muscles, and a frequency that can be applied to the surrounding muscles.

2. The urine storage capacity estimation system according to claim 1, wherein the estimation means estimates the urine storage capacity of a subject by comparing the estimated urine storage capacity based on the at least two types of bioelectrical impedance measured by the measurement means with the estimated urine storage capacity based on the at least two types of bioelectrical impedance measured by the measurement means, using the estimated urine storage capacity based on the at least two types of bioelectrical impedance as a reference value when the amount of urine stored is small relative to the capacity of the subject's bladder.

3. The urine storage level estimation system according to claim 1, further comprising a notification means for notifying when the urine storage level exceeds a predetermined threshold.

4. The urine storage level estimation system according to claim 3, wherein the threshold is variable.

5. The urine storage capacity estimation system according to claim 1, wherein the measuring means measures at least two types of bioimpedances, namely a first bioimpedance measured by passing a high-frequency current that can be passed through the bladder and surrounding muscles, and a second bioimpedance measured by passing a low-frequency current that can be passed through the surrounding muscles, and the estimation means calculates the estimated urine storage capacity by correcting the value of the first bioimpedance using the value of the second bioimpedance to estimate the urine storage capacity.

6. The urine storage capacity estimation system according to claim 5, wherein the estimation means calculates the estimated urine storage volume by dividing the second bioimpedance by the first bioimpedance.

7. A computer functions as a measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and as an estimation means for estimating the amount of urine stored in the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the muscles of the bladder and surrounding muscles, and a frequency that can be applied to the muscles surrounding the bladder.

8. A urine storage capacity estimation device comprising: measuring means for measuring at least two types of bioimpedances corresponding to each frequency by applying current to the bladder at at least two different frequencies, and estimation means for estimating the urine storage capacity of the bladder based on the at least two types of bioimpedances, wherein the at least two frequencies include a frequency that can be applied to the bladder and surrounding muscles, and a frequency that can be applied to the surrounding muscles.

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