Urine volume estimation system, urine volume estimation method, and urine volume estimation program

Abstract

A urine volume estimation system 100 comprises: ultrasonic sensors 2 that transmit ultrasonic waves into the body of a subject and receive reflected waves; and an estimator 47 that estimates the urine volume in the bladder on the basis of detection results of the ultrasonic sensors 2. The ultrasonic sensors 2 include a plurality of the ultrasonic sensors 2, with which the transmission direction of the ultrasonic waves is shifted in a prescribed direction. The estimator 47 switches between a first estimation for estimating the urine volume in the bladder on the basis of the number of the ultrasonic sensors 2 that receive reflected waves from the bladder, and a second estimation for determining, from the detection results of the ultrasonic sensors 2, the span of the bladder in the transmission direction of the ultrasonic waves from the ultrasonic sensors 2, and for estimating the urine volume in the bladder on the basis of the determined span of the bladder.

Description

Urine volume estimation system, urine volume estimation method, and urine volume estimation program

[0001] The technology disclosed herein relates to a urine volume estimation system, a urine volume estimation method, and a urine volume estimation program.

[0002] For example, a system disclosed in Patent Document 1 transmits ultrasound waves into the body and estimates the amount of urine in the bladder based on the waves reflected from the bladder.

[0003] JP 2016-43274 A

[0004] There are various methods for estimating urine volume based on the results of ultrasound detection, as described above. Each method has its own advantages, so intensive research is being conducted to improve the performance of urine volume estimation.

[0005] The technology disclosed herein has been made in consideration of the above points, and its purpose is to improve the performance of urine volume estimation.

[0006] The urine volume estimation system disclosed herein comprises an ultrasonic sensor that transmits ultrasonic waves into the body of a subject and receives reflected waves, and an estimator that estimates the urine volume of the bladder based on the detection results of the ultrasonic sensors, wherein the ultrasonic sensors include a plurality of ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction, and the estimator switches between a first estimation that estimates the urine volume of the bladder based on the number of ultrasonic sensors that receive reflected waves from the bladder, and a second estimation that determines the extent of the bladder in the transmission direction of ultrasonic waves from each of the ultrasonic sensors from the detection results of the ultrasonic sensors and estimates the urine volume of the bladder based on the determined bladder extent.

[0007] The urine volume estimation method disclosed herein includes performing a first estimation to estimate the bladder urine volume based on the number of ultrasonic sensors that receive reflected waves from the bladder of ultrasonic waves transmitted into the subject's body using a plurality of ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction; performing a second estimation to determine the bladder extension in the transmission direction of the ultrasonic waves from each of the ultrasonic sensors from the detection results of the ultrasonic sensors, and estimating the bladder urine volume based on the determined bladder extension; and switching between the first estimation and the second estimation.

[0008] The urine volume estimation program disclosed herein enables a computer to realize the following functions: a first estimation that estimates the bladder urine volume based on the number of ultrasonic sensors that receive reflected waves from the bladder of ultrasonic waves transmitted into the subject's body using multiple ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction; a second estimation that calculates the bladder expansion in the transmission direction of ultrasonic waves from each of the ultrasonic sensors from the detection results of the ultrasonic sensors and estimates the bladder urine volume based on the calculated bladder expansion; and a function to switch between the first estimation and the second estimation.

[0009] According to the urine volume estimation system, the performance of urine volume estimation can be improved.

[0010] According to the urine volume estimation method, the performance of urine volume estimation can be improved.

[0011] According to the urine volume estimation program, it is possible to improve the performance of urine volume estimation.

[0012] FIG. 1 is a schematic diagram of a urine volume estimation system. FIG. 2 is a schematic perspective view of a probe. FIG. 3 is a block diagram of the probe. FIG. 4 is a diagram showing the attached state of the probe. FIG. 5 is a diagram showing the inside of the casing with the lid removed. FIG. 6 is a cross-sectional view of the probe taken along line VI-VI in FIG. 5. FIG. 7 is a cross-sectional view of the probe taken along line VII-VII in FIG. 5. FIG. 8 is a schematic cross-sectional view of the lower abdomen of a human body with a probe attached. FIG. 9 is a block diagram showing the hardware configuration of a calculation device. FIG. 10 is a block diagram showing the functional configuration of a processor. FIG. 11 is an explanatory diagram for estimating the shape of the bladder based on the detection results of a first ultrasonic sensor. FIG. 12 is an explanatory diagram for estimating the shape of the bladder based on the detection results of a second ultrasonic sensor. FIG. 13 is a flowchart of basic processing by the control device. FIG. 14 is a flowchart of basic processing by the calculation device. FIG. 15 is a flowchart of processing by the calculation device in a urine volume estimation system according to Modification 1. FIG. 16 is a block diagram of a probe according to Modification 2. FIG. 17 is a block diagram showing the functional configuration of a processor according to Modification 2. Fig. 18 is a flowchart of the process of the control device according to Modification 2. Fig. 19 is a flowchart of the process of the arithmetic device according to Modification 2. Fig. 20 is a flowchart of the process of the arithmetic device according to Modification 3.

[0013] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Exemplary embodiments will now be described in detail with reference to the accompanying drawings. 1 is a schematic diagram of a urine volume estimation system 100. As shown in FIG.

[0014] The urine volume estimation system 100 includes an ultrasonic sensor 2 that transmits ultrasonic waves into the body of a subject and receives reflected waves, and a calculation device 4 that estimates the urine volume in the bladder based on the detection result of the ultrasonic sensor 2. The urine volume estimation system 100 estimates the urine volume in the bladder of the subject using ultrasonic waves. For example, the subject may include not only healthy individuals, but also elderly or physically disabled individuals who require care, or people who do not require care but who are physically disabled and take a long time to go to the toilet. However, the subject is not limited to these.

[0015] The urine volume estimation system 100 includes a probe 1 including an ultrasonic sensor 2. The probe 1 communicates with a computing device 4. For example, the probe 1 and the computing device 4 communicate wirelessly.

[0016] <Probe> Fig. 2 is a schematic perspective view of the probe 1. Fig. 3 is a block diagram of the probe 1. The probe 1 has an ultrasonic sensor 2 and a control device 3 that controls the ultrasonic sensor 2. The probe 1 further has a casing 10 that houses the ultrasonic sensor 2 and the control device 3. The casing 10 is formed in a flat shape. The casing 10 has a contact surface 11 that comes into contact with the skin of the subject's abdomen when the probe 1 is attached to the subject. The casing 10 has a main body 12 having an internal space, and a lid 13 attached to the main body 12. The main body 12 includes the contact surface 11.

[0017] FIG. 4 shows the attached state of the probe 1. The probe 1 is always attached to the subject. The probe 1 is placed on the subject's abdominal skin in a region corresponding to the bladder (e.g., the lower abdomen). For example, the probe 1 is attached to the subject's abdomen via an adhesive sheet 18 with the contact surface 11 in contact with the subject's abdomen. The adhesive sheet 18 has an adhesive surface and is attached to the abdomen via the adhesive surface. The adhesive sheet 18 has a holder 19 that detachably holds the probe 1. The adhesive sheet 18 and the holder 19 have an opening that exposes the probe 1 to the body surface. The probe 1 held by the holder 19 contacts the body surface through the opening. A gel or the like may be applied between the contact surface 11 and the abdomen to improve the transmittance of ultrasound to the abdomen. The probe 1 may also be attached to the subject by a method other than the adhesive sheet 18, for example, via a belt.

[0018] The ultrasonic sensor 2 transmits and receives ultrasonic waves. Specifically, the ultrasonic sensor 2 includes a piezoelectric element. The piezoelectric element vibrates in response to a drive voltage to generate ultrasonic waves, and upon receiving ultrasonic waves, generates an electrical signal in response to the vibrations. The ultrasonic sensor 2 transmits ultrasonic waves toward the subject, i.e., from the contact surface 11 of the casing 10.

[0019] FIG. 5 is a diagram showing the inside of the casing 10 with the lid 13 removed. The ultrasonic sensor 2 includes a plurality of first ultrasonic sensors 21 whose ultrasonic transmission directions are shifted in a predetermined first direction X and a plurality of second ultrasonic sensors 22 whose ultrasonic transmission directions are shifted in a second direction Y different from the first direction. Hereinafter, the direction in which the ultrasonic transmission directions of the first ultrasonic sensors 21 and the second ultrasonic sensors 22 are shifted is referred to as the "shift direction." That is, the shift direction of the plurality of first ultrasonic sensors 21 is the first direction X, and the shift direction of the plurality of second ultrasonic sensors 22 is the second direction Y. In this example, the first direction X and the second direction Y are perpendicular to each other. The probe 1 is attached to the subject so that the first direction X is oriented in the vertical direction of the body and the second direction Y is oriented in the horizontal direction (i.e., left-right direction) of the body. That is, with respect to the subject, the first direction X is the vertical direction and the second direction Y is the horizontal direction.

[0020] In this example, the ultrasonic sensors 2 include four first ultrasonic sensors 21 and three second ultrasonic sensors 22. However, one first ultrasonic sensor 21 also serves as a second ultrasonic sensor 22. Therefore, the total number of ultrasonic sensors 2 is six. When there is no need to distinguish between the first ultrasonic sensors 21 and the second ultrasonic sensors 22, they will simply be referred to as "ultrasonic sensors 2."

[0021] The four first ultrasonic sensors 21 each transmit ultrasonic waves toward a different portion of the body of the object in the first direction X. Specifically, the four first ultrasonic sensors 21 are arranged side by side in the first direction X within the casing 10. That is, the positions of the four first ultrasonic sensors 21 in the first direction X are different. When distinguishing between the four first ultrasonic sensors 21, alphabets are added to the end of the reference numerals. The four first ultrasonic sensors 21 are referred to as first ultrasonic sensor 21a, first ultrasonic sensor 21b, first ultrasonic sensor 21c, and first ultrasonic sensor 21d, in order from bottom to top in the first direction X.

[0022] Furthermore, the ultrasonic transmission angles of the four first ultrasonic sensors 21, specifically, the elevation and depression angles of the transmission directions, are different from one another. That is, the transmission directions of the four first ultrasonic sensors 21 are non-parallel to one another. FIG. 6 is a cross-sectional view of the probe 1 taken along line VI-VI in FIG. 5. The four first ultrasonic sensors 21 transmit ultrasonic waves radially in the vertical direction. Specifically, the transmission direction of the third first ultrasonic sensor 21c from the bottom is perpendicular to the contact surface 11. The transmission direction of the topmost first ultrasonic sensor 21d is more upward than the transmission direction of the first ultrasonic sensor 21c. The transmission direction of the second first ultrasonic sensor 21b from the bottom is more downward than the transmission direction of the first ultrasonic sensor 21c. The transmission direction of the bottommost first ultrasonic sensor 21a is more downward than the transmission direction of the first ultrasonic sensor 21b.

[0023] The four first ultrasonic sensors 21 transmit ultrasonic waves at approximately the same angle to the left and right. For example, in the left and right directions, i.e., the horizontal direction, the four first ultrasonic sensors 21 transmit ultrasonic waves toward the center of the subject, more specifically, toward the midline.

[0024] As shown in FIG. 5 , the three second ultrasonic sensors 22 each transmit ultrasonic waves toward a different portion of the subject's body in the second direction Y. In this example, the third-lowest first ultrasonic sensor 21c functions as the second ultrasonic sensor 22. Therefore, when describing the configuration of the third-lowest first ultrasonic sensor 21c as the second ultrasonic sensor 22, the first ultrasonic sensor 21c will be referred to as the second ultrasonic sensor 22. Specifically, the three second ultrasonic sensors 22 are arranged side by side in the second direction Y within the casing 10. That is, the positions of the three second ultrasonic sensors 22 in the second direction Y are different. Note that, when distinguishing between the three second ultrasonic sensors 22, letters will be added to the end of the reference numerals. The three second ultrasonic sensors 22 will be referred to as the second ultrasonic sensor 22a, the second ultrasonic sensor 22b, and the second ultrasonic sensor 22c, starting from the right side of the subject in the second direction Y. The second ultrasonic sensor 22b also functions as the first ultrasonic sensor 21c. The row of three second ultrasonic sensors 22 intersects with the row of four first ultrasonic sensors 21. At the intersection, a first ultrasonic sensor 21c, i.e., a second ultrasonic sensor 22b, is disposed.

[0025] Furthermore, the ultrasonic transmission angles of the three second ultrasonic sensors 22, specifically the left-right angles of the transmission directions, are different from one another. That is, the transmission directions of the three second ultrasonic sensors 22 are non-parallel to one another. FIG. 7 is a cross-sectional view of the probe 1 taken along line VII-VII in FIG. 5. The three second ultrasonic sensors 22 transmit ultrasonic waves radially in the left-right direction. Specifically, the transmission direction of the middle second ultrasonic sensor 22b is perpendicular to the contact surface 11. The transmission direction of the right-side second ultrasonic sensor 22a is more rightward than the transmission direction of the second ultrasonic sensor 22b. The transmission direction of the left-side second ultrasonic sensor 22c is more leftward than the transmission direction of the second ultrasonic sensor 22b.

[0026] The elevation and depression angles of the transmission directions of the three second ultrasonic sensors 22 are approximately the same.

[0027] 8 is a schematic cross-sectional view of the lower abdomen of a human body fitted with the probe 1. The bladder 91 is located in the lower abdomen. The pubic bone 92 is located diagonally below and in front of the bladder 91.

[0028] The probe 1 is attached to the abdomen of the subject so that the ultrasonic waves emitted from the first ultrasonic sensor 21 spread in the up-down direction and the ultrasonic waves emitted from the second ultrasonic sensor 22 spread in the left-right direction. The first ultrasonic sensor 21 transmits ultrasonic waves toward different positions in the up-down direction within the body. The second ultrasonic sensor 22 transmits ultrasonic waves toward different positions in the left-right direction within the body. The bladder 91 expands three-dimensionally as the amount of urine increases. Therefore, different positions in the up-down direction and different positions in the left-right direction correspond to directions in which the bladder 91 expands. Note that the bladder 91 expands particularly significantly in the up-down direction. That is, the first ultrasonic sensor 21 is positioned to transmit ultrasonic waves toward different positions in directions in which the bladder 91 expands relatively significantly.

[0029] <Control Device> The control device 3 is disposed on a substrate 15. As shown in Fig. 6, the substrate 15 is housed in the casing 10 (see also Fig. 7). As shown in Fig. 3, the control device 3 has a transmitter 31 that outputs a drive voltage to the ultrasonic sensor 2, a receiver 32 that receives a reception signal from the ultrasonic sensor 2, a switch 33 that switches the ultrasonic sensor 2 connected to the transmitter 31 and the receiver 32, an alarm 35 that notifies the outside of various information, a communicator 36 that communicates with the outside, a memory 37 that stores various programs and data, a processor 38 that performs overall control of the control device 3, and a memory 39.

[0030] The transmitter 31 supplies a drive voltage to the ultrasonic sensor 2. The transmitter 31 has a pulse generator 31a and an amplifier 31b. The pulse generator 31a generates a pulse signal with a predetermined pulse width and voltage value. The pulse generator 31a may be configured to be able to change the pulse width, number of pulses, and frequency. The amplifier 31b amplifies the pulse signal from the pulse generator 31a and outputs it to the ultrasonic sensor 2 as a drive voltage.

[0031] The receiver 32 receives the electrical signal from the ultrasonic sensor 2. The receiver 32 has an amplifier 32a, a detector 32b, and an A / D converter 32c. The amplifier 32a amplifies the received signal from the ultrasonic sensor 2. The detector 32b performs envelope detection on the amplified received signal. The detector 32b may also amplify the detected received signal. The A / D converter 32c A / D converts the detected received signal.

[0032] The switch 33 selectively switches the ultrasonic sensor 2 connected to the transmitter 31 and the receiver 32 from among the plurality of ultrasonic sensors 2 .

[0033] The alarm 35 is, for example, an LED lamp. The LED lamp lights up and down to notify the subject of various information (for example, that the subject has urinated).

[0034] The communicator 36 is a communication module and communicates with an external communication device such as the arithmetic device 4. For example, the communicator 36 communicates according to the Bluetooth (registered trademark) standard. As shown in FIG. 1 , the communicator 36 may be connected to the Internet via a repeater 52 and communicate with a server 51 or the like.

[0035] The storage unit 37 is a computer-readable recording medium, and is configured, for example, by a flash memory. The storage unit 37 stores various programs and information required for executing the processes of the processor 38. Furthermore, the storage unit 37 stores the received signal received by the receiver 32, information acquired from the outside via the communication unit 36, and the like.

[0036] The processor 38 controls the transmitter 31, the receiver 32, the switch 33, the alarm 35, and the communication device 36 based on the programs stored in the storage device 37. The processor 38 is configured with a processor such as a CPU (Central Processing Unit). The processor 38 performs various processes by loading the programs stored in the storage device 37 or the like into a memory 39 and executing them. The processor 38 may be realized by hardware such as an LSI (Large Scale Integration) having the same functions as a processor.

[0037] Specifically, the processor 38 receives signals from the outside. For example, the processor 38 receives signals from external devices such as the arithmetic device 4 via the communication device 36 and performs processing according to the signals (for example, activating the alarm 35). The processor 38 receives measurement commands from the arithmetic device 4. The processor 38 executes transmission and reception of ultrasonic waves by the ultrasonic sensor 2. For example, the processor 38 controls the switch 33 to switch between the ultrasonic sensors 2 connected to the transmitter 31 and the receiver 32. The processor 38 controls the transmitter 31 to output a drive voltage to the ultrasonic sensor 2. The processor 38 controls the receiver 32 to convert the received signal of the ultrasonic sensor 2 into a digital signal. The processor 38 controls the communication device 36 to transmit signals to external devices such as the arithmetic device 4. For example, the processor 38 transmits the received signal of the ultrasonic sensor 2 to the outside.

[0038] The memory 39 is a computer-readable recording medium, and is composed of, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), or a RAM (Random Access Memory).

[0039] <Calculation Device> The calculation device 4 is a portable smart device such as a smartphone or tablet terminal. The calculation device 4 is capable of communicating with the probe 1 and receives and stores the received signal transmitted from the probe 1 (i.e., the received signal (received wave) of the ultrasonic sensor 2 that has been received and processed by the receiver 32). Hereinafter, the received signal received from the probe 1 will also be simply referred to as the "received signal of the ultrasonic sensor 2." The calculation device 4 also analyzes the stored received signal of the ultrasonic sensor 2. Specifically, the calculation device 4 estimates the urine volume in the bladder based on the received signal of the ultrasonic sensor 2. The calculation device 4 stores a program, data, etc. for estimating the urine volume.

[0040] The arithmetic device 4 can operate an application program (hereinafter simply referred to as a "dedicated app") dedicated to the urine volume estimation system 100. By using the dedicated app, the arithmetic device 4 transmits and receives signals to and from the probe 1, analyzes signals received by the ultrasonic sensor 2, and so on.

[0041] The calculation device 4 may store information about the subject. The information about the subject includes, for example, a user ID that identifies the subject, a device ID that identifies the probe 1, and information about the subject's urine collection and urination. The user ID and device ID are registered in advance by the user. The information about the subject's urine collection and urination is, for example, an allowable urine volume (an allowable urine level, which will be described later), and a common initial value is set in advance by default.

[0042] 9 is a block diagram showing the hardware configuration of the arithmetic device 4. The arithmetic device 4 includes a processor 41, a memory 42, a communicator 43, and a storage device 44. The arithmetic device 4 may further include a touch panel.

[0043] The processor 41 is configured with a processor such as a CPU (Central Processing Unit). The processor 41 executes various processes by loading a program stored in a storage unit 44 or the like into the memory 42 and executing the program. The processor 41 may be realized by hardware such as an LSI (Large Scale Integration) having the same functions as a processor.

[0044] The memory 42 is a computer-readable recording medium, and is composed of, for example, a ROM (Read Only Memory), an EPROM (Erasable Programmable ROM), an EEPROM (Electrically Erasable Programmable ROM), or a RAM (Random Access Memory).

[0045] The communicator 43 is a communication module and communicates with the control device 3 of the probe 1. For example, the communicator 43 performs communication according to the Bluetooth (registered trademark) standard. Furthermore, the communicator 43 may communicate with external devices other than the probe 1, such as a server 51, by performing mobile communication and / or Wi-Fi communication.

[0046] The memory 44 is a computer-readable recording medium. The memory 44 stores various programs and various information necessary for executing the processing of the processor 41. For example, the memory 44 stores a urine volume estimation program 81 and thresholds used for urine volume estimation. The urine volume estimation program 81 causes the processor 41, which serves as a computer, to realize a function of continuously estimating the urine volume of the bladder based on the reflected waves from the bladder received by the ultrasonic sensor 2, which transmits ultrasonic waves into the body of the subject and receives the reflected waves.

[0047] Fig. 10 is a block diagram showing the functional configuration of the processor 41. The processor 41 realizes the functions shown in Fig. 10 by loading a urine volume estimation program 81 and the like into the memory 42 and executing it. The processor 41 has an indicator 45, an acquirer 46, and an estimator 47. The receiving function, the acquiring function, and the estimating function are realized by the processor 41 executing the urine volume estimation program 81 stored in the memory 44.

[0048] The indicator 45 outputs commands to each part of the user terminal 4 or to the probe 1. The indicator 45 accepts operation input from a user such as a subject. The calculation device 4 displays various screens and images on the display. For example, the calculation device 4 displays a screen of a urine volume estimation app on the display. The app screen includes an estimated urine volume and operation buttons, etc. For example, the app screen displays a button for executing the second estimation, which will be described later. When the user touches the button for executing the second estimation, the indicator 45 accepts input for executing the second estimation. When the indicator 45 accepts input for executing the second estimation, it outputs a measurement command to the probe 1, specifically to the control device 3.

[0049] The acquirer 46 receives, i.e., acquires, the received signal of the ultrasonic sensor 2 through communication with the probe 1. The acquirer 46 stores the received signal together with the time when the signal was received (i.e., acquisition time) in the memory 44. The calculation device 4 accumulates the received signal and the acquisition time.

[0050] The estimator 47 estimates the amount of urine in the bladder based on the received signal of the ultrasonic sensor 2, i.e., the detection result of the ultrasonic sensor 2. The estimator 47 continuously estimates the amount of urine in the bladder. Specifically, the estimator 47 analyzes the received signal of the ultrasonic sensor 2 stored in the memory 44. The estimator 47 continuously estimates the amount of urine in the bladder based on the reflected wave from the bladder received by the ultrasonic sensor 2, and stores the estimated amount of urine in the memory 44.

[0051] The estimator 47 switches between a first estimation that estimates the urine volume of the bladder based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, and a second estimation that determines the extent of the bladder in the transmission direction of ultrasonic waves from each ultrasonic sensor 2 from the detection results of the ultrasonic sensors 2 and estimates the urine volume of the bladder based on the determined bladder extent. The accuracy of the second estimation is higher than that of the first estimation. In other words, the first estimation is a rough estimate of the urine volume, and the second estimation is a more detailed estimate of the urine volume.

[0052] In this example, in the first estimation, the volume of urine in the bladder is estimated based on the detection result of the first ultrasonic sensor 21, and the detection result of the second ultrasonic sensor 22 is not used. The estimator 47 estimates the volume of urine in the bladder based on the number of first ultrasonic sensors 21 that receive reflected waves from the bladder. In detail, the estimator 47 checks whether a bladder is detected in each of the received signals of the four first ultrasonic sensors 21. The estimator 47 checks whether a reflected wave from the bladder is included in each of the received signals of the four first ultrasonic sensors 21. The reception time period during which the reflected wave from the bladder is expected to be returned is generally known. The estimator 47 determines whether a reflected wave is present in that reception time period. For example, in the first estimation, a reflected wave from the posterior wall of the bladder is used. The estimator 47 determines that the first ultrasonic sensor 21 has detected the bladder if the received signal contains a reflected wave from the bladder.

[0053] The estimator 47 then calculates the urine level based on which first ultrasonic sensor 21 is detecting the bladder. While the bladder expands upward as the urine volume increases, the multiple first ultrasonic sensors 21 transmit ultrasonic waves toward different positions in the vertical direction, as shown in FIG. 8 . Therefore, the greater the urine volume, the greater the number of first ultrasonic sensors 21 detecting the bladder. The estimator 47 determines the urine level based on which first ultrasonic sensors 21 are detecting the bladder, starting from the bottom. When none of the first ultrasonic sensors 21 is detecting the bladder, the urine level is set to "0." When the uppermost sensor detecting the bladder is the first ultrasonic sensor 21a, the urine level is set to "2.5." When the uppermost sensor detecting the bladder is the first ultrasonic sensor 21b, the urine level is set to "5." When the uppermost sensor detecting the bladder is the first ultrasonic sensor 21c, the urine level is set to "7.5." When the uppermost sensor detecting the bladder is the first ultrasonic sensor 21d, the urine level is set to "10." That is, urine levels are rated on a scale of 0-10.

[0054] The estimator 47 calculates the final current urine level by averaging the urine levels of a predetermined number of recent detections, including the current urine level. For example, the estimator 47 rounds off the average of the multiple urine levels to express the current urine level as a number with one decimal place. The estimator 47 stores the current urine level together with the time of estimation in the memory 44. The estimator 47 may display the current urine level on an application screen of the computing device 4.

[0055] In this example, in the second estimation, the urine volume of the bladder is estimated based on the detection results of both the first ultrasonic sensor 21 and the second ultrasonic sensor 22. The estimator 47 determines the extent of the bladder in the transmission direction of the ultrasonic waves from each of the first ultrasonic sensor 21 and the second ultrasonic sensor 22 from the detection results of the first ultrasonic sensor 21 and the second ultrasonic sensor 22, and estimates the urine volume of the bladder based on the determined bladder extent. In detail, the estimator 47 determines the depth of the bladder based on the received signals of the four first ultrasonic sensors 21 and two second ultrasonic sensors 22 (three if the dual-purpose first ultrasonic sensor 21 is included; the same applies below), and estimates the bladder capacity based on the bladder depths corresponding to the four first ultrasonic sensors 21 and two second ultrasonic sensors 22. The estimator 47 determines the positions of the front and rear walls of the bladder in the transmission directions of ultrasound from each of the four first ultrasonic sensors 21 and the two second ultrasonic sensors 22, based on the reflected waves from the front and rear walls of the bladder contained in the received signals. The estimator 47 determines the positions of the front and rear walls of the bladder based on the reception times of the reflected waves, the propagation times of the ultrasound waves, and the transmission directions of the ultrasound waves. This allows the positions of the front and rear walls of the bladder in up to six directions, i.e., up to 12 wall positions of the bladder to be determined.

[0056] The estimator 47 estimates the bladder capacity based on the determined positions of the bladder walls. FIG. 11 is an explanatory diagram for estimating the shape of the bladder based on the detection results of the first ultrasonic sensor 21. FIG. 12 is an explanatory diagram for estimating the shape of the bladder based on the detection results of the second ultrasonic sensor 22. For example, the estimator 47 calculates a three-dimensional shape that approximates the bladder from the positions of the bladder walls at multiple locations. The approximate three-dimensional shape is, for example, an ellipsoid. Specifically, since the four first ultrasonic sensors 21 each transmit ultrasonic waves in the same left-right direction but in different up-down directions, as shown in FIG. 11 , the positions of multiple walls in a cross section extending in the up-down and front-back directions, i.e., a cross section perpendicular to the left-right direction, are determined from the received signals of the four first ultrasonic sensors 21. The estimator 47 calculates an ellipse E1 that approximates the bladder from the positions of the multiple walls in the cross section perpendicular to the left-right direction. On the other hand, since the three second ultrasonic sensors 22 each transmit ultrasonic waves in the same up-down direction but in different left-right directions, as shown in FIG. 12 , the positions of multiple walls in a cross section extending in the left-right and front-back directions, i.e., a cross section perpendicular to the up-down direction, can be determined from the received signals of the three second ultrasonic sensors 22. The estimator 47 determines an ellipse E2 that approximates the bladder in the cross section perpendicular to the up-down direction from the positions of the multiple walls. The estimator 47 determines an ellipsoid that approximates the bladder based on the approximate ellipses E1 and E2 of the bladder in the two orthogonal cross sections. The estimator 47 estimates the volume of the determined approximate ellipsoid as the bladder urine volume. The estimator 47 stores the estimated urine volume in the memory 44 together with the time of the estimation timing. The estimator 47 may display the estimated urine volume on an application screen of the calculation device 4.

[0057] Thus, in this example, the first estimation estimates the bladder's urine volume based on the expansion of the bladder in one dimension, specifically, the vertical direction. In the first estimation, the urine volume is represented by an index called the urine level. On the other hand, in the second estimation, the bladder's urine volume is estimated based on the expansion of the bladder in at least two dimensions, specifically, the shift direction of the ultrasonic sensor 2 and the transmission direction of the ultrasonic waves. In this example, since the shift directions of the ultrasonic sensor 2 are the vertical and horizontal directions, the bladder's urine volume is estimated based on the expansion of the bladder in three dimensions, specifically, the vertical, horizontal, and front-to-back directions. In the second estimation, the urine volume is represented by the bladder capacity.

[0058] In the first estimation, the urine volume is estimated based on the number of ultrasonic sensors 2 that detect the reflected waves from the bladder, making the estimation simple and requiring a small computational load. In the second estimation, the bladder expansion in the ultrasonic transmission direction is calculated from the detection results of the ultrasonic sensors 2, and the bladder capacity is further calculated from the bladder expansion in the transmission direction, resulting in a high estimation accuracy.

[0059] The estimator 47 normally performs the first estimation, and switches from the first estimation to the second estimation when a predetermined switching condition is met. For example, the switching condition is receipt of an execution command for the second estimation. For example, the calculation device 4 displays an application screen on the display. A second estimation execution button is displayed on the application screen. The user touches the execution button as an operation for executing the second estimation. When the execution button is operated, the indicator 45 outputs an execution command for the second estimation to the estimator 47. When the execution command for the second estimation is received, the estimator 47 switches from the first estimation to the second estimation and executes the second estimation. In this example, when the second estimation is completed, the estimator 47 switches from the first estimation to the second estimation. In other words, the condition for switching from the second estimation to the first estimation is completion of the second estimation.

[0060] <Operation of Urine Volume Estimation System> The processing of the urine volume estimation system 100 will be described in detail below. First, the operation of the probe 1 will be described. The probe 1 transmits and receives ultrasound under the control of the control device 3. Fig. 13 is a flowchart of basic processing by the control device 3.

[0061] Specifically, in step S101, the processor 38 determines whether or not the measurement conditions are satisfied. The measurement conditions are conditions for transmitting and receiving ultrasonic waves. In this example, the measurement conditions include a first measurement condition and a second measurement condition. The first measurement condition is that a predetermined measurement timing arrives. The measurement timing is the timing for transmitting and receiving ultrasonic waves for the first estimation, and is repeated at a predetermined measurement period. The second measurement condition is that a measurement command is received from an external device (e.g., the computing device 4).

[0062] The processor 38 determines whether either the first measurement condition or the second measurement condition is satisfied. The processor 38 measures time to monitor the arrival of measurement timing and monitors the reception of a measurement command. When the measurement timing arrives or a measurement command is received, the processor 38 determines that the measurement condition is satisfied. The processor 38 repeats step S101 until the measurement condition is satisfied. In other words, the processor 38 waits for the measurement condition to be satisfied.

[0063] If the measurement conditions are met, in step S102, the processor 38 switches the switch 33 to cause the four first ultrasonic sensors 21 and the two second ultrasonic sensors 22 to transmit and receive ultrasonic waves in sequence. For example, the processor 38 controls the switch 33 so that the first ultrasonic sensor 21a is connected to the transmitter 31 and the receiver 32. The processor 38 then outputs a pulse signal generation command to the transmitter 31, causing the transmitter 31 to supply a drive voltage to the first ultrasonic sensor 21a. The first ultrasonic sensor 21a transmits ultrasonic waves based on the drive voltage and receives reflected waves from within the body. The received signal from the first ultrasonic sensor 21a is amplified, detected, and A / D converted by the receiver 32. The processor 38 stores the A / D converted received signal in the memory 39. The processor 38 sequentially switches the switch 33 to perform similar control on the other ultrasonic sensors 2.

[0064] When transmission and reception of ultrasonic waves by all of the ultrasonic sensors 2 is completed, in step S103, the processor 38 transmits the reception signals of the first ultrasonic sensor 21 and the second ultrasonic sensor 22, which are stored in the memory 39, to the calculation device 4 via the communicator 36. Thereafter, the processor 38 returns to step S101 and repeats the process from step S101.

[0065] In this way, each time the measurement conditions are satisfied, the processor 38 causes all of the ultrasonic sensors 2 to transmit and receive ultrasonic waves and transmit the received signals to the calculation device 4. The processor 38 periodically causes the ultrasonic sensors 2 to transmit and receive ultrasonic waves at the measurement timing, and also causes the ultrasonic sensors 2 to transmit and receive ultrasonic waves when a measurement command is received.

[0066] Next, a description will be given of the processing of the arithmetic device 4. Fig. 14 is a flowchart of the basic processing of the arithmetic device 4. The arithmetic device 4 executes the following processing by loading the urine volume estimation program 81 and the like into the memory 42 and executing it.

[0067] In step S201, the indicator 45 determines whether or not an input to execute the second estimation has been received. As described above, the indicator 45 receives the input to execute the second estimation when the user touches the execute second estimation button on the application screen of the computing device 4. Step S201 corresponds to switching between the first estimation and the second estimation.

[0068] If the indicator 45 has not received an input for executing the second estimation, the estimator 47 determines in step S202 whether the estimation timing has arrived. The estimation timing is repeated at a predetermined estimation period. In this example, the estimation period is the same as the measurement period.

[0069] If the estimation timing has not arrived, the indicator 45 returns to the process of step S201, that is, the arrival of the estimation timing and the reception of an input to execute the second estimation are awaited.

[0070] When the estimation timing arrives, the estimator 47 performs a first estimation in step S203. The estimator 47 determines the urine level based on the most recent received signals from the four first ultrasonic sensors 21. Then, the estimator 47 determines the average value of a predetermined number of most recent urine levels, including the urine levels of the most recent received signals from the four first ultrasonic sensors 21, as the final current urine level. The final current urine level can be output in various ways. For example, the estimator 47 may display the final current urine level on the display of the computing device 4. The estimator 47 may transmit the final current urine level to an external device such as the server 51. The estimator 47 may store the final current urine level in the memory 44. Step S203 corresponds to performing the first estimation.

[0071] When the first estimation is completed, the indicator 45 returns to the process of step S201. In other words, the estimator 47 periodically executes the first estimation at the estimation timing unless the indicator 45 receives an input to execute the second estimation.

[0072] On the other hand, if the indicator 45 receives an input to execute the second estimation, the indicator 45 outputs a measurement command to the probe 1 in step S204. The measurement command is transmitted to the probe 1 via the communication device 43. As a result, the probe 1 transmits and receives ultrasound for the second estimation.

[0073] Thereafter, in step S205, the indicator 45 determines whether or not the reception signal of the ultrasonic sensor 2 has been received from the probe 1. Specifically, the indicator 45 determines whether or not the acquirer 46 has received the reception signal of the ultrasonic sensor 2. The indicator 45 repeats step S205 until the reception signal of the ultrasonic sensor 2 is received. In other words, the indicator 45 waits until the reception signal of the ultrasonic sensor 2 is returned in response to the measurement command.

[0074] When the ultrasonic sensor 2 receives a reception signal, the indicator 45 outputs a command to execute the second estimation to the estimator 47 in step S206. The estimator 47 receives the command and executes the second estimation. The estimator 47 calculates the urine volume based on the most recent reception signals of the four first ultrasonic sensors 21 and the most recent reception signals of the two second ultrasonic sensors 22. In the second estimation, the estimated urine volume is output as a volume, not as a urine level. The estimated urine volume can be output in various ways. For example, the estimator 47 may display the estimated urine volume on a display of the calculation device 4. The estimator 47 may transmit the estimated urine volume to an external device. The estimator 47 may store the estimated urine volume in the memory 44. Step S206 corresponds to executing the second estimation.

[0075] When the second estimation is completed, the indicator 45 returns to the process of step S201. That is, the estimator 47 periodically executes the first estimation as described above, and executes interrupt processing for the second estimation when a command to execute the second estimation is received.

[0076] In this way, the first estimation, which estimates the urine volume of the bladder based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, and the second estimation, which calculates the bladder expansion in the transmission direction of the ultrasonic sensors 2 from the detection results of the ultrasonic sensors 2 and estimates the urine volume of the bladder based on the calculated bladder expansion, are switched between. The computational load of the first estimation is reduced compared to the second estimation. The estimation accuracy of the second estimation is higher compared to the first estimation. Thus, by switching between the first estimation and the second estimation, urine volume estimation with a low computational load and urine volume estimation with high estimation accuracy can be selectively used. In other words, multiple estimation methods can be realized with a single probe 1. Since the advantages of multiple estimation methods can be enjoyed with a single probe 1, the performance of urine volume estimation can be improved.

[0077] In this example, the second estimation estimates the urine volume based on both the detection results of the first ultrasonic sensor 21 and the detection results of the second ultrasonic sensor 22. That is, in the second estimation, the expansion of the expansion in the shift direction of the first ultrasonic sensor 21 is evaluated in addition to the shift direction of the second ultrasonic sensor 22. This further improves the estimation accuracy in the second estimation.

[0078] In this example, the first estimation is normally performed, and the second estimation is performed when an execution input is received. In this example, the execution input is output when the user performs an operation to perform the second estimation in the app. Therefore, the first estimation is normally performed with a low computational load, and the highly accurate second estimation is performed at the user's discretion. Under normal circumstances, the computational load can be reduced by the first estimation. For example, since the urgency of urination is low under normal circumstances, the first estimation can be performed to monitor the approximate urine volume and predict the timing of urination. Then, when the user wants to know the precise urine volume, the second estimation is performed at the user's discretion. For example, the second estimation can be performed before and after urination to determine the precise urine volume.

[0079] <Modification 1> Next, a description will be given of a modification of the urine volume estimation system 100. The urine volume estimation system 100 according to Modification 1 differs from the above-described urine volume estimation system 100 in the conditions under which the second estimation is performed.

[0080] More specifically, in the urine volume estimation system 100 according to the first modification, the estimator 47 switches between the first estimation and the second estimation depending on the urine volume. The estimator 47 performs the first estimation when the urine volume is relatively small, and performs the second estimation when the urine volume is relatively large. In the first modification, the second estimation is also performed at the same estimation timing as the first estimation. Therefore, the measurement conditions of the probe 1 include the first measurement conditions but do not include the second measurement conditions. In other words, the probe 1 transmits and receives ultrasound at periodic measurement timings and transmits the received signals to the calculation device 4.

[0081] 15 is a flowchart of the processing of the calculation device 4 in the urine volume estimation system 100 according to Modification 1. In step S301, the estimator 47 determines whether or not the estimation timing has arrived. The estimation timing is repeated at a predetermined estimation period.

[0082] If the estimation timing has not arrived, the estimator 47 repeats the process of step S301. In other words, the estimator 47 waits for the arrival of the estimation timing.

[0083] When the estimation timing arrives, the estimator 47 determines in step S302 whether the most recent estimated urine volume is equal to or greater than a predetermined threshold value α. The most recent estimated urine volume is the urine volume estimated at the previous estimation timing, regardless of whether it is based on the first estimation or the second estimation. In this example, the estimated urine volume based on the first estimation and the estimated urine volume based on the second estimation are expressed in different formats, so the threshold value α is set for each of the estimated urine volume based on the first estimation and the estimated urine volume based on the second estimation. That is, a threshold value α expressed in urine levels and a threshold value α expressed in urine volume are set. The urine volume corresponding to the threshold value α expressed in urine levels is approximately equivalent to the threshold value α expressed in urine volume. If the previous urine volume estimation is the first estimation, the estimator 47 makes the determination in step S302 using the threshold value α expressed in urine levels. If the previous urine volume estimation is the second estimation, the estimator 47 makes the determination in step S302 using the threshold value α expressed in urine volume. The threshold value α is stored in the memory 44. Step S302 corresponds to switching between the first estimation and the second estimation.

[0084] If the most recent estimated urine volume is less than the threshold value α, the estimator 47 performs a first estimation in step S303. The process of step 303 is the same as the process of step 203. When the first estimation is completed, the estimator 47 returns to the process of step S301. Step S303 corresponds to performing the first estimation.

[0085] If the most recent estimated urine volume is equal to or greater than the threshold value α, the estimator 47 performs a second estimation in step S304. In this example, the estimator 47 performs the second estimation at the same estimation timing as in the first estimation. The received signal of the ultrasonic sensor 2 used in the second estimation is the most recent received signal of the ultrasonic sensor 2 periodically transmitted from the probe 1. The method of calculating the urine volume by the second estimation is the same as in step S206. When the second estimation is completed, the estimator 47 returns to the processing of step S301. Step S304 corresponds to performing the second estimation.

[0086] As described above, in the first modification, urine volume estimation using the first estimation or the second estimation is periodically performed at the estimated timing. The first estimation and the second estimation are selected according to the urine volume. Specifically, the first estimation is performed when the urine volume is relatively small, and the second estimation is performed when the urine volume is relatively large. The greater the urine volume, the greater the urgency of urination. Therefore, by performing the second estimation when the urine volume is relatively large, the timing of urination can be predicted based on a highly accurate estimated urine volume. On the other hand, when the urine volume is relatively small, the urine volume can be monitored while reducing the computational load.

[0087] <Modification 2> Next, a urine volume estimation system 100 according to Modification 2 will be described. The urine volume estimation system 100 according to Modification 2 differs from the basic urine volume estimation system 100 described above in the conditions under which the second estimation is performed. Components of the urine volume estimation system 100 according to Modification 2 that differ from the basic urine volume estimation system 100 are assigned reference numerals in the 300s. Of the components assigned reference numerals in the 300s, components whose reference numerals in the tens digit and below are the same as those of the basic urine volume estimation system have the same functions as the corresponding components of the basic urine volume estimation system.

[0088] The urine volume estimation system 100 according to the second modification further includes a posture sensor 312 that detects the posture of the subject, and a posture determiner 348 that determines the posture of the subject.

[0089] 16 is a block diagram of a probe 301 according to Modification 2. The probe 301 further includes an attitude sensor 312. The attitude sensor 312 is housed in the casing 10 of the probe 301. For example, the attitude sensor 312 is disposed on the substrate 15. The attitude sensor 312 detects acceleration. For example, the attitude sensor 312 is an acceleration sensor that detects acceleration along each of three orthogonal axes. An acceleration signal is output from the attitude sensor 312.

[0090] The processor 38 of the probe 301 acquires the detection signal of the attitude sensor 312 when transmitting and receiving ultrasonic waves. The processor 38 controls the communicator 36 to transmit the signals from the receiver 32 and the attitude sensor 312 to the outside.

[0091] The arithmetic device 304 receives and stores the received signals transmitted from the probe 301 (i.e., the received signals (received waves) of the ultrasonic sensor 2 received and processed by the receiver 32 and the acceleration signals from the attitude sensor 312). Hereinafter, the acceleration signals received from the probe 301 will also be simply referred to as the "acceleration of the attitude sensor 312."

[0092] 17 is a block diagram showing the functional configuration of a processor 341 according to Modification 2. The processor 341 of the calculation device 4 has an attitude determiner 348 in addition to an indicator 45, an acquirer 46, and an estimator 47.

[0093] The acquirer 46 receives, i.e., acquires, the acceleration of the attitude sensor 312 in addition to the received signal of the ultrasonic sensor 2 through communication with the control device 3. The acquirer 46 stores the received signal and acceleration together with the time when the received signal and acceleration were received (i.e., acquisition time) in the memory 44. The memory 44 accumulates the received signal, acceleration, and acquisition time.

[0094] The posture determiner 348 determines whether the posture of the subject is an estimable posture for which the second estimation is possible or an estimable posture for which the second estimation is difficult, based on the posture detected by the posture sensor 312. This posture determination function is realized by the processor 341 executing a urine volume estimation program 81 stored in the memory 44. The urine volume estimation program 81 causes the processor 341 as a computer to realize the following functions: a function of continuously estimating the urine volume of the bladder based on the ultrasonic sensor 2 that transmits ultrasonic waves into the subject's body and receives reflected waves from the bladder, and a function of determining whether the posture of the subject is an estimable posture for which the urine volume is difficult to estimate, based on the posture of the subject detected by the posture sensor 312. More specifically, the posture determiner 348 determines the direction of gravity based on the acceleration in three axes and estimates the posture of the subject based on the direction in which gravity is acting. The posture determiner 348 then determines whether the estimated posture is an estimable posture.

[0095] Here, an estimable posture is a posture in which the contact state of the probe 301 with the body surface is appropriately maintained. The estimable posture may vary depending on the shape of the probe 301, the method of attaching the probe 301 to the body surface, and the like. There are various modes of estimable postures. For example, in a standing or sitting position, the posture determiner 348 determines that the posture is estimable when the rotation angle around the left-right axis (i.e., the tilt angle in the front-to-back direction) is within a predetermined range and the rotation angle around the front-to-back axis (i.e., the tilt angle in the left-to-right direction) is also within a predetermined range. Specifically, in a standing or sitting position, a posture in which the subject is leaning backward and the tilt to the left or right is small is an estimable posture. In a lying position, the posture determiner 348 determines that the posture is estimable when the rotation angle around the midline (the axis passing through the head and trunk) is within a predetermined range. Specifically, in a lying position, a supine position or a prone position is an estimable posture.

[0096] On the other hand, postures other than the estimable postures are difficult to estimate. There are various postures that are difficult to estimate. For example, one form of posture that is difficult to estimate is a lateral position. Another form of posture that is difficult to estimate is a standing or sitting position in a forward-leaning state.

[0097] The estimator 47 performs a first estimation when the attitude determiner 348 determines that the attitude is difficult to estimate, and performs a second estimation when the attitude determiner 348 determines that the attitude is estimable. For example, the estimator 47 periodically performs the first estimation at the estimation timing, and performs the second estimation when the attitude determiner 348 determines that the attitude is estimable during that time.

[0098] 18 is a flowchart of the process of the control device 3 according to the modified example 2. The process of the control device 3 according to the modified example 2 is basically the same as the process of the basic control device 3.

[0099] Specifically, in step S401, the processor 38 determines whether the measurement conditions are met. The processing in step S401 is the same as step S101. The measurement conditions include a first measurement condition and a second measurement condition. The first measurement condition is that a predetermined measurement timing occurs. The second measurement condition is that a measurement command is received from the outside (e.g., the computing device 4). When the measurement timing occurs or when the processor 38 receives the measurement command, the processor 38 determines that the measurement conditions are met. The processor 38 repeats step S401 until the measurement conditions are met.

[0100] If the measurement conditions are met, in step S402, the processor 38 switches the switch 33 to sequentially transmit and receive ultrasonic waves from the four first ultrasonic sensors 21 and the two second ultrasonic sensors 22. The processing in step S402 is similar to that in step S102.

[0101] In addition, in step S403, the processor 38 detects the acceleration of the attitude sensor 312. The processor 38 stores the acceleration signal from the attitude sensor 312 in the memory 39. The processing of step S403 is not included in the basic processing of the control device 3.

[0102] Next, in step S404, the processor 38 transmits the received signal of the first ultrasonic sensor 21, the received signal of the second ultrasonic sensor 22, and the acceleration of the attitude sensor 312, which are stored in the memory 39, to the calculation device 4 via the communicator 36.

[0103] Thereafter, the processor 38 returns to step S401 and repeats the process from step S401.

[0104] In this way, every time the measurement conditions are satisfied, the processor 38 executes transmission and reception of ultrasonic waves by all ultrasonic sensors 2 and detection of acceleration by the attitude sensor 312. Specifically, the processor 38 executes transmission and reception of ultrasonic waves by the ultrasonic sensors 2 and detection of acceleration by the attitude sensor 312 in addition to periodic measurement timing, when a measurement command is received.

[0105] Next, a description will be given of the processing of the arithmetic unit 4 according to Modification 2. FIG.

[0106] In step S501, the estimator 47 determines whether the estimation timing has arrived. The estimation timing is repeated at a predetermined estimation period. In this example, the estimation period is the same as the measurement period.

[0107] If the estimation timing has not arrived, the estimator 47 repeats the process of step S501. In other words, the estimator 47 waits for the arrival of the estimation timing.

[0108] When the estimation timing arrives, in step S502, the estimator 47 determines whether or not the determination by the posture determiner 348 is an estimable posture. Specifically, the posture determiner 348 determines whether or not the posture of the subject is an estimable posture, based on the latest acceleration of the posture sensor 312. Step S502 corresponds to switching between the first estimation and the second estimation.

[0109] If the posture determiner 348 determines that the posture is not estimable, the estimator 47 performs a first estimation in step S503. The processing in step S503 is the same as that in step S203. Note that the most recent received signal from the ultrasonic sensor 2 is used in the first estimation. The most recent received signal from the ultrasonic sensor 2 is included in the same set as the acceleration of the posture sensor 312 used to determine the posture of the subject. When the first estimation is completed, the estimator 47 returns to the processing in step S501. Step S503 corresponds to performing the first estimation.

[0110] On the other hand, if the posture determiner 348 determines that the posture is estimable, the estimator 47 performs a second estimation in step S504. The processing in step S504 is the same as that in step S206. Note that the second estimation uses the most recent received signal from the ultrasonic sensor 2. The most recent received signal from the ultrasonic sensor 2 is included in the same set as the acceleration of the posture sensor 312 used to determine the posture of the subject. When the second estimation is completed, the estimator 47 returns to the processing in step S501. Step S504 corresponds to performing the second estimation.

[0111] That is, the estimator 47 executes either the first estimation or the second estimation at periodic estimation timings. The posture of the subject is determined based on the acceleration of the posture sensor 312 corresponding to the received signal of the ultrasonic sensor 2 used for the first estimation or the second estimation, and the first estimation is selected if the posture is not an estimable posture, and the second estimation is selected if the posture is an estimable posture.

[0112] In this way, the system switches between a first estimation that estimates the urine volume based on the detection result of the first ultrasonic sensor 21 and a second estimation that estimates the urine volume based on the detection result of the second ultrasonic sensor 22. By switching between the first estimation and the second estimation, the urine volume in the bladder can be evaluated from different perspectives.

[0113] In addition, in the first estimation, the urine volume of the bladder is estimated based on the number of first ultrasonic sensors 21 that receive reflected waves from the bladder. Meanwhile, in the second estimation, the extent of the bladder in the transmission direction of the second ultrasonic sensors 22 is determined from the detection results of the second ultrasonic sensors 22, and the urine volume of the bladder is estimated based on the determined bladder extent. In other words, in the first estimation, it is sufficient to know whether or not there are reflected waves from the bladder, and the accuracy of the reception time of the reflected waves from the bladder, etc., is not necessary. Meanwhile, in the second estimation, the extent of the bladder in the transmission direction of the ultrasound is determined based on the reception time of the reflected waves from the bladder. Therefore, the estimation accuracy of the urine volume in the second estimation depends on the accuracy of the reception time of the reflected waves from the bladder, etc. Because the second estimation is performed based on reflected waves acquired when the subject's posture is an estimable posture, the estimation accuracy of the urine volume by the second estimation can be improved.

[0114] <Modification 3> Next, a urine volume estimation system 100 according to Modification 3 will be described. The urine volume estimation system 100 according to Modification 3 differs from the basic urine volume estimation system 100 described above in the conditions under which the second estimation is performed. Like the urine volume estimation system 100 according to Modification 2, the urine volume estimation system 100 according to Modification 3 further includes a posture sensor 312 that detects the posture of the subject and a posture determiner 348 that determines the posture of the subject. However, the calculation device 4 according to Modification 3 performs switching between the first estimation and the second estimation based on the posture of the subject in combination with switching based on the estimated urine volume.

[0115] 20 is a flowchart of the processing of the arithmetic unit 4 according to Modification 3. The flowchart of the processing of the arithmetic unit 4 according to Modification 3 is basically the same as the flowchart of the processing of the arithmetic unit 4 according to Modification 1. However, in the flowchart of FIG. 20, step S605 is inserted between step S302 and step S304 in the flowchart of FIG. 15.

[0116] More specifically, if it is determined in step S302 that the most recent estimated urine volume is equal to or greater than the threshold value α, the estimator 47 determines in step S605 whether the posture determined by the posture determiner 348 is an estimable posture. The posture determiner 348 determines whether the posture of the subject is an estimable posture based on the most recent acceleration of the posture sensor 312. Step S605 corresponds to switching between the first estimation and the second estimation.

[0117] If the attitude determiner 348 determines that the attitude is not an estimable attitude, the estimator 47 performs a first estimation in step S303. On the other hand, if the attitude determiner 348 determines that the attitude is an estimable attitude, the estimator 47 performs a second estimation in step S304.

[0118] As described above, in the third modification, urine volume estimation using the first estimation or the second estimation is periodically performed at the estimation timing. The first estimation and the second estimation are selected according to the urine volume and posture. Specifically, the first estimation is performed when the urine volume is below the threshold value α or the subject is not in an estimable posture, and the second estimation is performed when the urine volume is equal to or greater than the threshold value α and the subject is in an estimable posture. The greater the urine volume, the greater the urgency of urination. However, the second estimation is not selected simply because the urine volume is large; the second estimation is selected when the urine volume is large and the subject's posture is in an estimable posture. Even if the urine volume is large, the first estimation is selected when the posture is not an estimable posture. In other words, the second estimation is selected when both the necessity and feasibility of highly accurate urine volume estimation are satisfied. When the urine volume is small, the necessity for highly accurate urine volume estimation is low, so the first estimation is selected regardless of posture. As a result, when the urine volume is relatively small, the urine volume is monitored while reducing the computational load.

[0119] Other Embodiments As described above, the above-described embodiments have been described as examples of the technology disclosed in the present application. However, the technology of the present disclosure is not limited to these embodiments and can be applied to embodiments in which modifications, substitutions, additions, omissions, etc. are made as appropriate. Furthermore, the components described in the above-described embodiments can be combined to create new embodiments. Furthermore, the components described in the accompanying drawings and detailed description may include not only components essential for solving the problem, but also components that are not essential for solving the problem in order to exemplify the technology. Therefore, the fact that these non-essential components are described in the accompanying drawings or detailed description should not be interpreted as immediately determining that these non-essential components are essential.

[0120] The above embodiment may be configured as follows.

[0121] The probe 1 can be placed anywhere on the body surface. The method of attaching the probe 1 is not limited to the above method. For example, the contact surface 11 may be formed of an adhesive surface and attached to the abdomen of the subject. Alternatively, tape may be attached to the body surface from above the probe 1.

[0122] The number of the multiple ultrasonic sensors 2 is not limited to six. The number of the first ultrasonic sensors 21 is not limited to four and may be three or less or five or more. The number of the second ultrasonic sensors 22 is not limited to three and may be two or less or four or more. One of the first ultrasonic sensors 21 does not have to also serve as the second ultrasonic sensor 22. The multiple ultrasonic sensors 2 may include only the first ultrasonic sensor 21 and not the second ultrasonic sensor 22. Alternatively, the multiple ultrasonic sensors 2 may include only the second ultrasonic sensor 22 and not the first ultrasonic sensor 21. In addition to the first ultrasonic sensor 21 and the second ultrasonic sensor 22, the multiple ultrasonic sensors 2 may further include another ultrasonic sensor whose shift direction is different from that of the first ultrasonic sensor 21 and the second ultrasonic sensor 22.

[0123] The arrangement of the multiple ultrasonic sensors 2 is not limited to the arrangement described above. It is sufficient that the ultrasonic transmission directions of the multiple first ultrasonic sensors 21 are at least offset in the first direction X. For example, the ultrasonic transmission directions of the multiple first ultrasonic sensors 21 may be further offset in a direction different from the first direction X. That is, the multiple first ultrasonic sensors 21 may also be offset from each other in the second direction Y, i.e., arranged in a staggered pattern. As long as the arrangement of the multiple first ultrasonic sensors 21 is offset in the first direction X, the elevation and depression angles of the multiple first ultrasonic sensors 21 may be parallel to each other. The same applies to the second ultrasonic sensor 22. The first direction X and the second direction Y do not have to be perpendicular to each other.

[0124] Furthermore, the casing 10 is not limited to the above configuration. For example, a protrusion may be provided on the contact surface 11 of the casing 10. The ultrasonic sensor 2 may be built into the protrusion. In this case, the protrusion improves the adhesion of the part of the casing 10 where the ultrasonic sensor 2 is built into the skin (body surface), facilitating the incidence of ultrasonic waves into the human body. This improves the bladder detection capability. The casing 10 may be formed in a roughly disk shape.

[0125] The control device 3 is integrated with the probe 1, i.e., housed in the casing 10, but is not limited to this. The control device 3 may be formed separately from the probe 1. In this case, the control device 3 may be connected to the probe 1 by wire or wirelessly. The control device 3 may be divided, with a part of the control device 3 housed inside the probe 1 and the remaining part of the control device 3 located outside the probe 1.

[0126] The configuration of the control device 3 is not limited to the above-described configuration. For example, although the transmitter 31 inputs a pulse signal as a drive signal to the probe 1, the drive signal is not limited to a pulse signal. The drive signal may be a burst wave instead of a pulse wave. Furthermore, the alarm 35 is not limited to an LED lamp, but may be a display, an alarm, or a vibrator.

[0127] The measurement conditions for transmitting and receiving ultrasound waves in the probe 1 are not limited to the above-mentioned conditions. For example, the calculation device 4 may monitor periodic measurement timings, and when the measurement timing arrives, the calculation device 4 may transmit a measurement command to the probe 1. In this case, the measurement condition is that the control device 3 receives the measurement command. In other words, the calculation device 4 may manage the timing for transmitting and receiving ultrasound waves, and the control device 3 may passively transmit and receive ultrasound waves.

[0128] The measurement conditions of the probe 1 may include measurement conditions for the first estimation and measurement conditions for the second estimation. When the measurement conditions for the first estimation are satisfied, the probe 1 may cause only the ultrasonic sensor 2 used for the first estimation to transmit and receive ultrasonic waves. When the measurement conditions for the second estimation are satisfied, the probe 1 may cause only the ultrasonic sensor 2 used for the second estimation to transmit and receive ultrasonic waves. For example, when the measurement conditions for the first estimation are satisfied, the probe 1 may cause only the first ultrasonic sensor 21 to transmit and receive ultrasonic waves, but may not cause the second ultrasonic sensor 22 to transmit and receive ultrasonic waves. When the measurement conditions for the second estimation are satisfied, the probe 1 may cause both the first ultrasonic sensor 21 and the second ultrasonic sensor 22 to transmit and receive ultrasonic waves.

[0129] The communication between the calculation device 4 and the probe 1 may be wired rather than wireless. The communication between the calculation device 4 and an external device such as the server 51 is not essential.

[0130] The arithmetic device 4 does not have to be a smart device such as a smartphone. The arithmetic device 4 may be a personal computer, a server, or the like. In this case, the probe 1 may be connected to the Internet via a repeater 52 and communicate with the arithmetic device 4 via the Internet. Furthermore, the arithmetic device 4 may be capable of communicating with a user terminal such as a smart device. A user may perform an execution operation such as the second estimation via the user terminal, and an execution input may be transmitted from the user terminal to the arithmetic device 4.

[0131] The estimation methods for the first estimation and the second estimation are not limited to the above-described methods. In the first estimation, the detection result of the second ultrasonic sensor 22 may be used in addition to the detection result of the first ultrasonic sensor 21. Specifically, in the first estimation, the urine volume of the bladder may be estimated based on the number of first ultrasonic sensors 21 and second ultrasonic sensors 22 that receive reflected waves from the bladder. Alternatively, in the first estimation, only the detection result of the second ultrasonic sensor 22 may be used. Specifically, in the first estimation, the urine volume of the bladder may be estimated based on the number of second ultrasonic sensors 22 that receive reflected waves from the bladder.

[0132] The second estimation may use only the detection results of the first ultrasonic sensors 21 or only the detection results of the second ultrasonic sensors 22. Specifically, the second estimation may determine the bladder extension in the transmission direction of ultrasonic waves from each of the first ultrasonic sensors 21 from only the detection results of the first ultrasonic sensors 21, and estimate the bladder urine volume based on the determined bladder extension. Alternatively, the second estimation may determine the bladder extension in the transmission direction of ultrasonic waves from each of the second ultrasonic sensors 22 from only the detection results of the second ultrasonic sensors 22, and estimate the bladder urine volume based on the determined bladder extension. Note that, in estimating bladder capacity from the cross-section of the bladder in the second estimation, the cross-section of the bladder may approximate a shape other than an ellipse. For example, the cross-sectional shape of the bladder may be determined by spline interpolation of multiple bladder wall positions determined based on received signals.

[0133] For example, if the multiple ultrasonic sensors 2 have a first ultrasonic sensor 21 but do not have a second ultrasonic sensor 22, in the first estimation, the amount of urine in the bladder is estimated based on the number of first ultrasonic sensors 21 that receive reflected waves from the bladder, and in the second estimation, the extent of the bladder in the transmission direction of the ultrasonic waves from each of the first ultrasonic sensors 21 is determined from the detection results of the first ultrasonic sensors 21, and the amount of urine in the bladder is estimated based on the determined bladder extent.

[0134] The attitude sensor 312 is not limited to an acceleration sensor that detects acceleration in three orthogonal axes. The attitude sensor 312 may be a gyro sensor. The attitude sensor 312 may also have the function of the attitude determiner 348. For example, the attitude sensor 312 may have an internal threshold value for determining the attitude and output a signal according to the attitude determination result. The attitude sensor 312 may be separate from the probe 1. For example, the attitude sensor 312 may be attached to the subject separately from the probe 1 and be capable of communicating with the computing device 4.

[0135] The conditions for executing the first estimation or the second estimation in the arithmetic device 4 may be set arbitrarily. For example, in the basic processing of the arithmetic device 4 in FIG. 14 , the first estimation may be executed when an input to execute the first estimation is received, rather than when the estimation timing arrives. For example, an execute first estimation button and an execute second estimation button may be displayed on the application screen of the arithmetic device 4. The arithmetic device 4 may execute the first estimation when the execute first estimation button is operated, and the arithmetic device 4 may execute the second estimation when the execute second estimation button is operated. When an execution input is received, a measurement command is output to the probe 1 as in step S204. In steps S301 or S501 in other flowcharts, it may also be determined whether an execution input to execute urine volume estimation is received, rather than when the estimation timing arrives. When an execution input is received, a measurement command is output to the probe 1 as in step S204.

[0136] The above-described flowcharts are merely examples. Steps in the flowcharts may be changed, replaced, added, omitted, etc. as appropriate. The order of steps in the flowcharts may also be changed, and serial processing may be performed in parallel.

[0137] The functions performed by the components described herein may be implemented in circuitry or processing circuitry, including general-purpose processors, application-specific processors, integrated circuits, ASICs (Application Specific Integrated Circuits), a Central Processing Unit (CPU), conventional circuits, and / or combinations thereof, programmed to perform the described functions. A processor includes transistors and other circuits and is considered a circuit or processing circuit. A processor may also be a programmable processor that executes a program stored in a memory.

[0138] In this specification, a circuit, unit, or means is hardware that is programmed to realize or performs the described functions, which may be any hardware disclosed herein or any hardware known to be programmed to realize or perform the described functions.

[0139] If the hardware is a processor considered to be a type of circuitry, the circuit, means, or unit is a combination of hardware and software used to configure the hardware and / or processor.

[0140] [Aspects] The above-described embodiments are specific examples of the following aspects.

[0141] (Aspect 1) A urine volume estimation system 100 includes an ultrasonic sensor 2 that transmits ultrasonic waves into the body of a subject and receives reflected waves, and an estimator 47 that estimates the urine volume of the bladder based on the detection results of the ultrasonic sensors 2, the ultrasonic sensors 2 including a plurality of ultrasonic sensors 2 whose ultrasonic transmission directions are shifted in a predetermined direction, and the estimator 47 switches between a first estimation that estimates the urine volume of the bladder based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, and a second estimation that determines the extension of the bladder in the transmission direction of ultrasonic waves from each of the ultrasonic sensors 2 from the detection results of the ultrasonic sensors 2 and estimates the urine volume of the bladder based on the determined bladder extension.

[0142] With this configuration, in the first estimation, the urine volume of the bladder is estimated based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, allowing the urine volume of the bladder to be estimated with a relatively simple calculation. In the second estimation, the urine volume of the bladder is estimated based on the extension of the bladder in the transmission direction of ultrasonic waves from each ultrasonic sensor 2, allowing the urine volume of the bladder to be estimated with higher accuracy than in the first estimation. In other words, the estimator 47 can switch between a urine volume estimation with a simple calculation and a urine volume estimation with high accuracy. As a result, the advantages of multiple estimation methods can be enjoyed without changing the configuration of the ultrasonic sensors 2, thereby improving the performance of urine volume estimation.

[0143] (Aspect 2) In the urine volume estimation system 100 according to aspect 1, the estimator 47 normally performs the first estimation, and switches from the first estimation to the second estimation when a command to perform the second estimation is received.

[0144] According to this configuration, the estimator 47 basically performs the first estimation. Then, the estimator 47 performs the second estimation when receiving an execution command for the second estimation. For example, an execution command is input from the indicator 45 to the estimator 47 in response to an input operation from the user. Therefore, the first estimation is usually performed, and the second estimation is performed at the user's will. Alternatively, the execution command may be input to the estimator 47 due to a factor other than an input operation from the user. For example, the execution command may be input from the indicator 45 to the estimator 47 when a predetermined condition is satisfied. The predetermined condition may be a predetermined time. In this case, the second estimation is performed at a predetermined time every day. Alternatively, the predetermined condition may be that the estimated urine volume according to the first estimation reaches a predetermined value, or that the subject assumes a predetermined posture.

[0145] (Aspect 3) In the urine volume estimation system 100 according to aspect 1 or aspect 2, the estimator 47 switches from the first estimation to the second estimation when the urine volume estimated based on the first estimation reaches a predetermined threshold value α.

[0146] According to this configuration, the first estimation is performed when the estimated urine volume is less than the threshold value α, and the second estimation is performed when the estimated urine volume is equal to or greater than the threshold value α. As a result, the first estimation and the second estimation are switched depending on the urine volume. For example, if the estimation accuracy of the second estimation is higher than that of the first estimation, a urine volume estimation with high estimation accuracy is performed when the estimated urine volume is relatively large. As a result, a urine volume estimation with high estimation accuracy is performed when the urgency of urination is high.

[0147] (Aspect 4) The urine volume estimation system 100 according to any one of Aspects 1 to 3 further includes a posture sensor 312 that detects the posture of the subject, and a posture determiner 348 that determines whether the posture of the subject is an estimable posture for which the second estimation is possible or a difficult-to-estimate posture for which the second estimation is difficult, based on the posture detected by the posture sensor 312, and the estimator 47 performs the first estimation when the posture determiner 348 determines that the posture is the difficult-to-estimate posture, and performs the second estimation when the posture determiner 348 determines that the posture is the estimable posture.

[0148] According to this configuration, the posture sensor 312 and the posture determiner 348 determine whether the posture of the subject is an estimable posture or a difficult-to-estimate posture. Then, if the posture of the subject is an estimable posture, the second estimation is performed, and if the posture of the subject is an estimable posture, the first estimation is performed. The urine volume estimation is performed by receiving reflected waves of ultrasound transmitted into the body of the subject. Therefore, some postures of the subject are suitable for transmitting and receiving ultrasound, and some are not. By performing the second estimation when the posture is suitable for the second estimation, the accuracy of the second estimation can be improved.

[0149] (Aspect 5) A method for estimating urine volume includes: performing a first estimation to estimate the urine volume of the bladder based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder of ultrasonic waves transmitted into the body of a subject using a plurality of ultrasonic sensors 2, each of which has a transmission direction of the ultrasonic waves shifted in a predetermined direction; performing a second estimation to determine the extent of the bladder in the transmission direction of the ultrasonic waves from each of the ultrasonic sensors 2 from the detection results of the ultrasonic sensors 2, and estimating the urine volume of the bladder based on the determined bladder extent; and switching between the first estimation and the second estimation.

[0150] With this configuration, in the first estimation, the urine volume of the bladder is estimated based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, allowing the urine volume of the bladder to be estimated with a relatively simple calculation. In the second estimation, the urine volume of the bladder is estimated based on the extension of the bladder in the transmission direction of ultrasonic waves from each ultrasonic sensor 2, allowing the urine volume of the bladder to be estimated with higher accuracy than in the first estimation. In other words, the estimator 47 can switch between a urine volume estimation with a simple calculation and a urine volume estimation with high accuracy. As a result, the advantages of multiple estimation methods can be enjoyed without changing the configuration of the ultrasonic sensors 2, thereby improving the performance of urine volume estimation.

[0151] (Mode 6) The urine volume estimation program 81 causes the computer to realize a function of executing a first estimation that estimates the urine volume of the bladder based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder of ultrasonic waves transmitted into the subject's body using multiple ultrasonic sensors 2 whose ultrasonic transmission directions are shifted in a predetermined direction; a function of executing a second estimation that determines the bladder expansion in the transmission direction of ultrasonic waves from each of the ultrasonic sensors 2 from the detection results of the ultrasonic sensors 2 and estimates the urine volume of the bladder based on the determined bladder expansion; and a function of switching between the first estimation and the second estimation.

[0152] With this configuration, in the first estimation, the urine volume of the bladder is estimated based on the number of ultrasonic sensors 2 that receive reflected waves from the bladder, allowing the urine volume of the bladder to be estimated with a relatively simple calculation. In the second estimation, the urine volume of the bladder is estimated based on the extension of the bladder in the transmission direction of ultrasonic waves from each ultrasonic sensor 2, allowing the urine volume of the bladder to be estimated with higher accuracy than in the first estimation. In other words, the estimator 47 can switch between a urine volume estimation with a simple calculation and a urine volume estimation with high accuracy. As a result, the advantages of multiple estimation methods can be enjoyed without changing the configuration of the ultrasonic sensors 2, thereby improving the performance of urine volume estimation.

[0153] 100 Urine volume estimation system 2 Ultrasonic sensor 21 First ultrasonic sensor 22 Second ultrasonic sensor 312 Orientation sensor 47 Estimator 348 Orientation determiner X First direction Y Second direction

Claims

1. An ultrasonic sensor that transmits ultrasonic waves into the body of a subject and receives reflected waves, and an estimator that estimates the urine volume in the bladder based on the detection result of the ultrasonic sensor, wherein the ultrasonic sensor includes a plurality of ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction, and the estimator includes: a first estimation that estimates the urine volume in the bladder based on the number of the ultrasonic sensors that receive the reflected waves from the bladder; and a second estimation that obtains the expansion of the bladder in the ultrasonic transmission direction from each of the ultrasonic sensors from the detection result of the ultrasonic sensors and estimates the urine volume in the bladder based on the obtained expansion of the bladder, and switches between the first estimation and the second estimation. A urine volume estimation system.

2. The urine volume estimation system according to claim 1, wherein the estimator normally performs the first estimation and switches the first estimation to the second estimation when a command to execute the second estimation is received.

3. The urine volume estimation system according to claim 1, wherein the estimator switches the first estimation to the second estimation when the urine volume estimated based on the first estimation reaches a predetermined threshold.

4. The urine volume estimation system according to claim 1, further comprising a posture sensor that detects the posture of the subject, and a posture determination device that determines whether the posture of the subject is a posture that enables the second estimation or a posture that makes the second estimation difficult based on the posture detected by the posture sensor, wherein the estimator performs the first estimation when the determination by the posture determination device is the posture that makes the second estimation difficult, and performs the second estimation when the determination by the posture determination device is the posture that enables the second estimation.

5. Performing a first estimation of estimating the urine volume in the bladder based on the number of the ultrasonic sensors that receive the reflected waves from the bladder of the ultrasonic waves transmitted into the body of the subject using a plurality of ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction; obtaining the expansion of the bladder in the ultrasonic transmission direction from each of the ultrasonic sensors from the detection result of the ultrasonic sensors and performing a second estimation of estimating the urine volume in the bladder based on the obtained expansion of the bladder; and switching between the first estimation and the second estimation. A urine volume estimation method.

6. A urine volume estimation program that causes a computer to implement a function of performing a first estimation of estimating the urine volume in the bladder based on the number of ultrasonic sensors that receive the reflected wave from the bladder of the ultrasonic waves transmitted into the body of the subject using a plurality of ultrasonic sensors whose ultrasonic transmission directions are shifted in a predetermined direction; a function of obtaining the expansion of the bladder in the ultrasonic transmission direction from each of the ultrasonic sensors from the detection results of the ultrasonic sensors and performing a second estimation of estimating the urine volume in the bladder based on the obtained expansion of the bladder; and a function of switching between the first estimation and the second estimation.

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