An apparatus and method for measuring bladder fullness

Abstract

This invention belongs to the field of medical electronics technology, specifically a device and method for measuring bladder fullness. The device comprises an ultrasonic transducer, an ultrasonic excitation module, a signal acquisition module, a calculation and processing module, and a user prompt module. The ultrasonic excitation module includes a channel selection switch and an ultrasonic pulse generation circuit. The selection switch controls the connection between the transducer array elements and the excitation and signal acquisition modules, while the pulse generation circuit generates an excitation signal. The signal acquisition module amplifies, filters, and performs analog-to-digital conversion on the ultrasonic echo signal. The calculation and processing module calculates the curvature characteristics of the anterior bladder wall surface using a specific algorithm and measures bladder fullness based on changes in these curvature characteristics. The measurement results of bladder fullness are finally presented in a user-acceptable manner through the user prompt module. This device is available in integrated and discrete versions, allowing for flexible configuration according to different user groups and application scenarios.

Description

Technical Field

[0001] This invention belongs to the field of medical electronic technology, specifically relating to a device and method for measuring bladder fullness. Background Technology

[0002] Childhood enuresis, commonly known as bedwetting, clinically refers to the involuntary urination that occurs in children over 5 years of age who are unable to wake up from their sleep at night. According to statistics from the ICCS (International Continence Society for Children), the prevalence of enuresis in children is very high, with approximately 16% of 5-year-olds and 10% of 7-year-olds suffering from it, and about 2-3% of these children will continue to have it into adulthood.

[0003] Desmopressin and bedwetting alarms are first-line clinical treatments for childhood nocturnal enuresis, effectively curing most cases of monosymptomatic nocturnal enuresis. Compared to drug therapy, bedwetting alarms are favored by doctors and parents due to their advantages of no toxic side effects, low recurrence rate, and no drug dependence.

[0004] Among numerous enuresis alarms based on different technologies, ultrasound can detect changes in the bladder located deep in the abdominal cavity in a non-invasive manner, without ionizing radiation, making it a widely used method for bladder detection due to its high safety. To measure bladder fullness, as in patent CN202110127230.4, a high-resolution ultrasound probe array converts the acquired ultrasound signals into a fine B-mode ultrasound image, and then uses a complex image processing algorithm to fit a three-dimensional model of the bladder to calculate bladder volume. This method often achieves relatively high accuracy, but requires high-end ultrasound probes, complex signal processing systems, and significant computing resources. Therefore, this method is not suitable for wearable products. Another method, as in patent CN202111055300.6, uses several single-element ultrasound transducers operating in A-mode to obtain the position of the anterior and posterior walls of the bladder and the echo amplitude information from the posterior wall, and then calculates the bladder volume using a specific algorithm. A-mode ultrasound systems have a relatively simple structure, but to obtain high signal-to-noise ratio posterior wall echo signals, high-frequency ultrasound excitation pulses are often used. High-voltage circuits increase system power consumption, and improper design or use can also pose certain safety hazards to the human body. Summary of the Invention

[0005] The purpose of this invention is to provide a device and method for measuring bladder fullness that is low in power consumption, easy to use, and safe.

[0006] The bladder fullness measurement device proposed in this invention is a low-pressure wearable ultrasound system that measures the degree of bladder fullness by detecting the radius of curvature of the anterior bladder wall. The device includes: an ultrasound excitation module 111, an ultrasound transducer 112, a signal acquisition module 113, a calculation and processing module 122, and a user prompt module 123; its usage can be divided into two forms:

[0007] Form 1 is a separation mode of sensing and measurement and calculation and display. The sensing and measurement part is composed of an ultrasonic excitation module 111, an ultrasonic transducer 112, and a signal acquisition module 113, referred to as the local sensing device 101, which is attached to the user's abdomen during use. The calculation and display part includes a calculation and processing module 122 and a user prompt module 123, serving as a remote data receiving and processing device 102. The local sensing device 101 also includes a data transmission module 114. The remote data receiving and processing device 102 also includes a data receiving module 121, used to realize communication and data transmission between the local sensing device 101 and the remote data receiving and processing device 102.

[0008] This device can transmit bladder measurement data to a guardian (such as the parents or caregivers of infants or young children) or a medical worker who is physically distant from the user;

[0009] Form 2 is the overall integrated mode, which integrates the ultrasonic excitation module 111, ultrasonic transducer 112, signal acquisition module 113, calculation and processing module 122, and user prompt module 123 together; it is attached to the user's abdomen when in use.

[0010] This format is suitable for users who can make local responses independently, such as teenagers and adults.

[0011] In this invention:

[0012] The ultrasonic transducer 112 is a one-dimensional or two-dimensional multi-element array composed of at least three single-element ultrasonic transducers; it is used to emit ultrasonic signals to the human body, receive echo signals reflected from within the body, and convert them into electrical signals, which are then sent to the signal acquisition module 113 for further processing; the typical ultrasonic signal frequency is between 1-5MHz. In use, the ultrasonic transducer is attached to the abdomen of the subject, emitting ultrasonic signals under external excitation. The echo signals reflected within the subject's body are received by the ultrasonic transducer and converted into electrical signals. This invention only needs to detect the echo signal from the anterior wall of the bladder, therefore the detection depth is shallow, the required excitation electrical signal for the transducer is small, and the ultrasonic signal is less affected by tissue attenuation during propagation within the body.

[0013] The ultrasonic excitation module 111 includes a channel selection switch and an ultrasonic pulse generation circuit. The channel selection switch is used to control the connection between the ultrasonic transducer 112 array element and the ultrasonic excitation module 111 and the signal acquisition module 113. The ultrasonic pulse generation circuit is used to generate an excitation signal. The form of the excitation signal includes: a low-voltage single pulse below the human body safety voltage, a low-voltage continuous pulse, or a frequency-modulated or phase-modulated coded signal with an amplitude less than the human body safety voltage. The coded signal is compressed by a matched filter or an unmatched filter to improve the signal-to-noise ratio of the echo signal.

[0014] The signal acquisition module 113 includes a filter, a small signal amplifier, and an analog-to-digital converter. The ultrasonic echo signal is filtered to remove noise signals with frequencies different from the ultrasonic signal, and then the echo is amplified by the small signal amplifier circuit. Finally, the amplified analog signal is input to the analog-to-digital converter circuit to generate a digital signal.

[0015] The computational processing module 122 is responsible for calculating the curvature characteristics of the current anterior wall of the bladder using a specific algorithm. The geometric shape of the bladder under different filling states is as follows: Figure 2 As shown, bladder fullness can be measured based on changes in the curvature characteristics of the anterior bladder wall. Indicators describing the curvature characteristics of the anterior bladder wall include, but are not limited to, the angle θ formed by each transducer element and the anterior bladder wall, the radius of curvature r, and the average radius of curvature r0. avg etc., such as Figure 3 As shown.

[0016] When the bladder fullness calculated based on the bladder surface curvature reaches a preset threshold, the user prompt module 123 automatically emits sound, light, vibration, and other prompts to remind the subject to urinate or to remind the subject's guardian or medical staff to take appropriate measures.

[0017] The data transmission module 114 is responsible for sending the digitized echo signal to the remote data receiving and processing device 102 via Bluetooth, WiFi, mobile network communication (such as 4G / 5G, etc.); the local sensing device 101 is only responsible for collecting signals, while the more power-consuming signal analysis and data calculation functions are completed in the remote data receiving and processing device 102, which has more powerful computing capabilities and is not sensitive to power consumption.

[0018] The data receiving module 121 is responsible for receiving the digital echo signal sent by the data sending module 114, which is then processed by the calculation and processing module 122, and judged and prompted by the user prompt module 123.

[0019] This invention provides a method for measuring bladder fullness, such as... Figure 4 As shown, the specific steps are as follows:

[0020] Step S1: Initialize the system; In Form 1, the remote data receiving and processing device 102 sends a "start detection" command to the local sensing device 101, thereby starting the detection process; In Form 2, the detection process is started by activating the switch on the sensor computing integrated device 103.

[0021] Step S2: The sensing device starts the detection process; each element in the ultrasonic transducer 112 is excited in sequence to generate ultrasonic signals; after the ultrasonic signals are emitted, all elements begin to collect echo signals.

[0022] In step S3, after receiving the echo, the sensing device immediately performs filtering, amplification and analog-to-digital conversion on the signal through the signal acquisition module 113. In the first form, the processed echo signal is transmitted to the remote data receiving and processing device 102 through the data transmission module 114. In the second form, the echo signal is directly transmitted to the local calculation and processing module 122.

[0023] Step S4: Calculate the curvature of the anterior bladder wall based on the received echo signal; the specific calculation process is as follows:

[0024] The ultrasound signal emitted by element i is reflected by the bladder wall, and the resulting echo is received by all elements. The maximum amplitude of the echo received by each element is compared. Assuming the maximum amplitude occurs in element j, the x-axis distance between elements i and j is a fixed distance dx between the elements. i-j The distance dz from the bladder wall to the element numbered i in the z-direction can be calculated based on the echo received at element number i. i ,like Figure 3 As shown, the distance can be obtained through methods such as time-of-flight or by calculating the sound wave transmission distance based on the echo amplitude and attenuation coefficient; taking the time-of-flight method as an example,

[0025]

[0026] Where v is the speed at which ultrasound travels through human tissue, and t i,0 t is the time when the ultrasonic excitation module 111 emits a pulse through the array element numbered i. i,1 The moment when the signal acquisition module 113 detects the front wall signal through the array element numbered i;

[0027]

[0028] The angle θ between each array element and the local surface of the bladder can be calculated using this method. i Where i∈[1,N], N is the total number of single array elements of the ultrasound transducer 112 array; the included angle θ can be used as an indicator of bladder fullness. As bladder fullness increases, it depends on the specific position of ultrasound transducer element i facing the anterior wall of the bladder. i It exhibits a monotonic change that either increases or decreases; utilizing the difference in angle |θ between two adjacent array elements. i+1 -θ i The radius of curvature r of the current surface can be calculated using the following formula, which is the distance dx between two adjacent array elements. i

[0029]

[0030] As bladder fullness increases, the radius of curvature of the bladder surface at a fixed location exhibits a monotonic change, either increasing or decreasing.

[0031] The curvature radii calculated from each array element are combined into a matrix [r1,…r] to characterize the current bladder surface curvature. N This matrix can be used to characterize bladder fullness through mathematical analysis or machine learning. For example, the average radius of curvature r is obtained by averaging the sum of the measured radii of curvature of each element. avg This is used to characterize bladder fullness;

[0032]

[0033] Step S5: If the remote terminal detects that the curvature characteristics of the anterior wall of the bladder reach a preset threshold, a urination prompt message is issued.

[0034] This invention provides a device for measuring bladder fullness, employing a multi-element ultrasound transducer array. The transducer operates in A-mode ultrasound, featuring a simple structure and easy wearability. Furthermore, it measures bladder fullness solely by detecting changes in the radius of curvature of the anterior bladder wall, eliminating the need to detect the posterior bladder wall located deep within the abdominal cavity as required by other ultrasound systems. Therefore, it can be implemented using a low-pressure ultrasound system, significantly improving device safety and reducing power consumption. Attached Figure Description

[0035] Figure 1 This is a block diagram of the device architecture of the present invention.

[0036] Figure 2 This diagram shows the changes in the anterior wall curvature of the bladder under different filling conditions.

[0037] Figure 3 This is a schematic diagram of the transducer array elements for transmitting and receiving signals and measuring the included angle.

[0038] Figure 4 This is a flowchart of the detection system workflow.

[0039] Figure 5 The mean radius of curvature of the anterior bladder wall changes with bladder filling under experimental conditions. Detailed Implementation

[0040] The technical solutions of the embodiments of the present invention will be described in complete and clear form below with reference to the accompanying drawings. Obviously, the described embodiments are only representative embodiments of the present invention, and not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the protection scope of the present invention.

[0041] Figure 1This is a system architecture block diagram of the device of the present invention. The device includes: an ultrasonic excitation module 111, an ultrasonic transducer 112, a signal acquisition module 113, a calculation and processing module 122, and a user prompt module 123; its usage modes include an integrated mode and a mode where sensing and measurement are separated from calculation and display. Here, the integrated mode is taken as an example.

[0042] The ultrasonic transducer 112 employs a one-dimensional array of 10 ultrasonic transducer elements. The transducer elements are 1 square centimeter PZT piezoelectric ceramic sheets. Each element is assembled on a flexible circuit board to ensure the transducer is tightly attached to the abdomen of the object being measured. A 1 mm gap is maintained between each element.

[0043] The ultrasonic excitation module 111 includes a channel selection switch and an ultrasonic pulse generation circuit. The selection switch uses an electronic switch chip with low on-resistance. Channel selection switches are provided in both the ultrasonic signal transmission and reception channels to control the selection of different array elements during transmission and reception. To improve safety, this example uses a low-voltage (10V amplitude) coded signal in 13-bit Barker code format, where each Barker code element is composed of a sine wave. The center frequency of the sine wave is 2MHz. The echo signal uses a matched filter to achieve pulse compression, thereby improving the signal-to-noise ratio of the echo signal.

[0044] The signal acquisition module 113 includes a filter, a small-signal amplifier, and an analog-to-digital converter. The ultrasonic echo signal is filtered by a filter circuit to remove noise signals with frequencies different from the ultrasonic signal, then amplified by an amplifier circuit, and finally the amplified analog signal is input to the analog-to-digital converter circuit to generate a digital signal.

[0045] The calculation and processing module 122 calculates the curvature characteristics of the current anterior bladder wall based on the received echo signal. It measures the bladder's fullness based on changes in the curvature characteristics. When the fullness reaches a preset threshold, the system uses the user prompt module 123 to issue vibration, sound, and light prompts to the subject to urinate. Figure 2 This shows the trend of bladder contour changes as the bladder fills. As bladder volume increases, the contour of the anterior bladder wall gradually flattens from an approximately hemispherical shape due to the accumulation of urine in the bladder, and the surface curvature decreases monotonically.

[0046] The method for measuring bladder fullness provided by this invention, such as Figure 4 As shown, the specific steps are as follows:

[0047] Step S1, Initialize the system; Start the detection process by turning on the switch on the local sensing and computing integrated device 103;

[0048] Step S2: The sensing device starts the detection process; each element in the ultrasonic transducer array 112 is sequentially excited to generate ultrasonic signals; after the ultrasonic signals are emitted, all elements begin to collect echo signals.

[0049] In step S3, after receiving the echo, the sensing device immediately performs filtering, amplification and analog-to-digital conversion on the signal through the signal acquisition module 113; the processed echo signal is then transmitted to the local calculation and processing module 214.

[0050] Step S4: Calculate the radius of curvature of the anterior bladder wall based on the received echo signal; the specific calculation process is as follows:

[0051] The ultrasound signal emitted by element i is reflected by the bladder wall, and the resulting echo is received by all elements. The maximum amplitude of the echo received by each element is compared. Assuming the maximum amplitude occurs in element j, the x-axis distance between elements i and j is a fixed distance dx between the elements. i-j The distance dz from the bladder wall to the element numbered i in the z-direction can be calculated based on the echo received at element number i. i ,like Figure 3 As shown, this example uses the time-offlight method for calculation:

[0052]

[0053] Where v is the speed at which ultrasound travels through human tissue (1450 m / s), and t i,0 t is the time when the ultrasonic excitation module 111 emits a pulse through the array element numbered i. i,1 The moment when the signal acquisition module 113 detects the front wall signal through the array element numbered i;

[0054]

[0055] The angle θ between each array element and the local surface of the bladder is calculated using the above formula. i Where i∈[1,N]; using the difference in angle between two adjacent array elements |θ i+1 -θ i The radius of curvature r of the current surface can be calculated using the following formula, which is the distance dx between two adjacent array elements. i

[0056]

[0057] The curvature radii calculated from each array element are combined into a matrix [r1,…r] to characterize the current bladder surface curvature. 10 The average radius of curvature r is obtained by averaging the sum of the measured radii of curvature of each array element.avg This is used to characterize bladder fullness;

[0058]

[0059] Step S5: If the remote terminal detects that the curvature of the anterior wall of the bladder reaches a preset threshold, it sends a urination prompt message to the user through the user prompt module 123 in the form of sound, light, vibration, etc.

[0060] A simulation experiment was conducted. A water-filled tank system was set up, and a rubber balloon was fixed in place to simulate the human bladder. A slow peristaltic pump outside the tank injected saline solution into the balloon at a flow rate of 5 ml / min to simulate the bladder filling process. An ultrasonic transducer array 112 was attached to the outer wall of the tank, with the transducers positioned directly in front of the balloon. Using the method described in this invention, the balloon volume was measured from 100 ml to 300 ml, and the change in the average radius of curvature of the balloon's front wall with volume was observed as follows: Figure 5 As shown. When the bladder volume is less than 100 ml, the bladder is often located behind the pubic bone and cannot be detected by the ultrasound system. Therefore, when the ultrasound system cannot detect a valid echo signal from the bladder, it can be determined that the current bladder volume is small, and therefore there is no need to issue a bedwetting warning. When the bladder volume is greater than 100 ml, the ultrasound system can detect bladder echoes and can continuously record the average radius of curvature of the anterior bladder wall, which monotonically increases with increasing filling degree. When the average radius of curvature exceeds a preset threshold, a urination warning can be triggered.

[0061] When a user uses the device for the first time, the system continuously records changes in the anterior bladder wall without issuing a urination alert. After the training phase, the system automatically sets an alarm threshold based on the recorded bladder changes. Once training is complete, the system operates according to the above process to provide an enuresis warning function.

Claims

1. A bladder fullness measuring device, characterized in that, The bladder fullness is measured by detecting the radius of curvature of the anterior bladder wall; the device includes: an ultrasound excitation module (111), an ultrasound transducer (112), a signal acquisition module (113), a calculation and processing module (122), and a user prompt module (123); it has two usage modes: Form 1 is a separation mode of sensing measurement and calculation display; the sensing measurement part is composed of an ultrasonic excitation module (111), an ultrasonic transducer (112) and a signal acquisition module (113), which is called a local sensing device (101). When in use, the local sensing device (101) is attached to the user's abdomen; the calculation display part includes a calculation processing module (122) and a user prompt module (123), which serve as a remote data receiving and processing device (102). The local sensing device (101) also includes a data transmission module (114); the remote data receiving and processing device (102) also includes a data receiving module (121); used to realize communication and data transmission between the local sensing device (101) and the remote data receiving and processing device (102); Form 2 is the overall integrated mode, which is the integration of an ultrasonic excitation module (111), an ultrasonic transducer (112), a signal acquisition module (113), a calculation and processing module (122), and a user prompt module (123); it is attached to the user's abdomen when in use.

2. The bladder fullness measuring device according to claim 1, characterized in that: The ultrasonic transducer (112) is a one-dimensional or two-dimensional multi-element array composed of at least three or more single-element ultrasonic transducers; it is used to transmit ultrasonic signals to the anterior wall of the human bladder, receive the echo signals reflected by the anterior wall of the bladder, convert them into electrical signals, and send them to the signal acquisition module (113) for further processing; the frequency of the ultrasonic signal is between 1-5MHz. The ultrasonic excitation module (111) includes a channel selection switch and an ultrasonic pulse generation circuit. The channel selection switch is used to control the connection between the ultrasonic transducer (112) array element and the ultrasonic excitation module (111) and the signal acquisition module (113). The ultrasonic pulse generation circuit is used to generate an excitation signal. The form of the excitation signal includes: a low-voltage single pulse below the human body safety voltage, a low-voltage continuous pulse, or a frequency-modulated or phase-modulated coded signal with an amplitude less than the human body safety voltage. The coded signal is compressed by a matched filter or an unmatched filter to improve the signal-to-noise ratio of the echo signal. The signal acquisition module (113) includes a filter, a signal amplifier, and an analog-to-digital converter. The ultrasonic echo signal is filtered to remove noise signals with frequencies different from the ultrasonic signal, and then the echo is amplified by the signal amplifier circuit. Finally, the amplified analog signal is input to the analog-to-digital converter circuit to generate a digital signal. The calculation and processing module (122) is responsible for calculating the curvature characteristics of the current anterior bladder wall and measuring the bladder fullness based on the changes in the curvature characteristics of the anterior bladder wall. The user prompt module (123) automatically emits sound, light or vibration prompts when the bladder fullness calculated based on the curvature of the bladder surface reaches a preset threshold. The data transmission module (114) is responsible for transmitting the digitized echo signal to the remote data receiving and processing device (102) via Bluetooth, WiFi or mobile network communication. The data receiving module (121) is responsible for receiving the digital echo signal sent by the data sending module (114), which is further processed by the calculation and processing module (122), and judged and prompted by the user prompt module (123).

3. The bladder fullness measuring device according to claim 2, characterized in that, The calculation and processing module (122) calculates the curvature characteristics of the current anterior bladder wall, and measures the bladder fullness based on the changes in the curvature characteristics of the anterior bladder wall. The specific process is as follows: The distance in the z-direction of the element numbered i in the ultrasonic transducer (112) array was calculated using the time-of-flight method. : in, This refers to the speed at which ultrasound travels through human tissues. The moment when the ultrasonic excitation module (111) emits a pulse through the array element numbered i, The moment when the signal acquisition module (113) detects the front wall signal through the array element numbered i; Calculate the angle between each array element and the local surface of the bladder. : in, , The total number of single array elements in the ultrasonic transducer (112) array; the interval between array elements numbered i and j in the x-direction is the fixed distance between array elements. ; Utilizing the difference in the angle between two adjacent array elements Spacing between two adjacent array elements The radius of curvature of the current surface is calculated using the following formula. The curvature radii calculated from each array element are combined into a matrix to characterize the current curvature of the bladder surface. This matrix becomes a feature characterizing bladder fullness through mathematical analysis or machine learning methods; specifically, the average radius of curvature is obtained by averaging the sum of the measured radii of curvature of each array element. This is used to characterize bladder fullness:

4. A method for measuring bladder fullness using the bladder fullness measuring device as described in any one of claims 1-3, characterized in that, The specific steps are as follows: Step S1, Initialize the system; In Form 1, the remote data receiving and processing device (102) sends a start detection command to the local sensing device (101) to start the detection process. In the second form, the detection process is started by activating the switch on the sensor-computing integrated device (103); Step S2: The sensing device starts the detection process; each element in the ultrasonic transducer (112) is excited in sequence to generate ultrasonic signals; after the ultrasonic signals are emitted, all elements start to collect echo signals. In step S3, after the sensing device receives the echo, it immediately performs filtering, amplification and analog-to-digital conversion on the signal through the signal acquisition module (113). In the first form, the processed echo signal is transmitted to the remote data receiving and processing device (102) through the data transmission module (114). In the second form, the echo signal is directly transmitted to the local calculation and processing module (122). Step S4: Calculate the curvature of the anterior bladder wall based on the received echo signal; the specific calculation process is as follows: The ultrasound signal emitted by element i is reflected by the bladder wall, and the resulting echo is received by all elements. The maximum amplitude of the echo received by each element is compared. Assuming the maximum amplitude occurs at element j, the x-axis distance between elements i and j is a fixed distance between elements. The distance from the bladder wall to the i-th element in the z-direction is calculated based on the echo received at element number i. The time-flight method is used for calculation: in, This refers to the speed at which ultrasound travels through human tissues. The moment when the ultrasonic excitation module (111) emits a pulse through the array element numbered i, The moment when the signal acquisition module (113) detects the anterior wall signal through the array element numbered i; the angle between each array element and the local surface of the bladder. for: in, , The total number of individual elements in the ultrasonic transducer (112) array; included angle As an indicator of bladder fullness, the degree of bladder fullness depends on the specific position of ultrasound transducer element i relative to the anterior bladder wall. It exhibits a monotonic change that either increases or decreases; it utilizes the difference in the angle between two adjacent array elements. Spacing between two adjacent array elements The radius of curvature of the current surface is calculated using the following formula. : The curvature radii calculated from each array element are combined into a matrix to characterize the current curvature of the bladder surface. This matrix becomes a feature characterizing bladder fullness through mathematical analysis or machine learning methods; specifically, the average radius of curvature is obtained by averaging the sum of the measured radii of curvature of each array element. This is used to characterize bladder fullness: Step S5: If the remote terminal detects that the curvature characteristics of the anterior wall of the bladder reach a preset threshold, a urination prompt message is issued.

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