Automatic bladder volume measuring device

Abstract

The invention discloses an automatic bladder volume measuring device and method. The automatic bladder volume measuring device comprises an ultrasonic probe module, a microprocessor, an FPGA control processor, a power source and an input module. The FPGA control processor generates a driving signal of the ultrasonic probe to the probe driving circuit according to an instrument starting pre-scanning or scanning signal sent by the input module, and the probe driving circuit controls the ultrasonic probe to scan and rotate; the probe signal receiving and transmitting circuit receives an ultrasonic signal reflected by the ultrasonic probe, carries out amplification and A / D conversion, converts the ultrasonic signal into a digital signal, and transmits the digital signal to the FPGA control processor for ultrasonic imaging and image processing, and rapid groove edge and volume calculation. According to the invention, accurate and quantitative measurement of the bladder volume can be conveniently and painlessly carried out, and the measurement of the bladder volume can be applied to wider fields.

Description

Technical Field

[0001] The invention relates to detection equipment in the technical field of medical equipment, and in particular to an automatic bladder volume measuring device. Background Art

[0002] As people's medical level continues to improve, intermittent catheterization is widely used not only in developed countries, but also in more and more developing countries. For patients with paraplegia and elderly urinary incontinence at home, it is necessary to measure bladder capacity and residual urine volume so as to perform catheterization in time to avoid urine backflow, kidney damage or bladder muscle atrophy.

[0003] The bladder capacity measuring instrument developed in the world in the early days is a device that uses a 3D ultrasonic probe to take the bladder as an ellipsoid shape and calculates the major axis, minor axis, and depth of the ellipsoid according to the volume formula of the ellipsoid to measure the bladder urine volume. However, the shape of each person's bladder is different, and the shape of the bladder when it is filled and not filled will also be different. Therefore, using a single mathematical model to measure the bladder urine volume will be inaccurate for most patients. Such a device will bring many inaccuracies in the evaluation of the physiological function of the bladder and the efficacy evaluation of the treatment process of bladder diseases, affecting the correct diagnosis of doctors. In particular, with the expansion of the application scope of quantitative determination of bladder capacity, such as controlling the bladder filling to 350ml, the displacement of organs can be avoided. Achieve the effect of precise radiotherapy. Therefore, accurate determination of bladder volume can cause minimal damage to normal tissues during pelvic radiotherapy, significantly reduce radiotherapy reactions, and significantly improve the treatment effect compared with ordinary radiotherapy. In view of the shortcomings of this device, researchers invented a device for measuring urine volume in bladder using flap-type superposition technology using a 3D ultrasonic probe (invention patent number: ZL 2012 1 0215960.0). The technology described in this patent application solves the problem of using a single mathematical model to measure urine volume in different bladder shapes, and establishes a mathematical model for measuring urine volume suitable for various bladder shapes. This device uses a 3D ultrasonic probe to measure urine volume in bladder using flap-type superposition technology. The capacity calculation formula (Vn = [0.87 × S (n) × S (n)] / a) in the flap-type superposition technology is also based on the ellipsoid empirical formula of two orthogonal sections. When the bladder shape cannot be approximated to an ellipsoid, the error will become larger. Moreover, the patent application number 201610929931.9 has already pointed out the shortcomings of this algorithm. Invention patent ZL 201210215960.0 uses the orange segment integral method to calculate the bladder volume. When the central axis of the probe does not deviate from the center of the bladder, the calculation accuracy can be guaranteed. However, if the central axis deviates from the center of the bladder, then over-calculation will occur when calculating the "large orange segment", such as Fig.13As shown in the figure, the cross-sectional area of ​​the bladder is S1+S2, but due to the deviation of the central axis, two additional areas, S3 and S4, are added during the calculation, thus affecting the entire volume calculation value and causing a larger error. Fig.13 It can be seen that if the central axis deviates from the bladder cross section, the error will be greater. Since the 3D ultrasound probe currently used in the world's bladder capacity measurement device is a motor-driven mechanical probe, there will be a certain deviation in the axis during the scanning process. In addition, if the operator does not place the probe in the center of the patient's bladder, the measurement error will be large, so the operator's technique is very demanding. Patent application number 201610929931.9 proposes to first convert the 12 faces of the bladder into a 3D stereo model, and then perform integration operations from top to bottom. Although the bladder capacity calculated in this way is not affected by the shape of the bladder, the formula is used when calculating each integral face. in This formula uses the area formula of a sector (center angle is 15°, radius is Ri) to calculate the area of ​​each small sector However, this calculation method is applicable to the case where the central axis is inside all the cut surface areas (even if the central axis is offset, the calculation of the capacity will not have errors), but when the central axis appears outside the cut surface area, such as Fig.14A As shown in the figure, section 1 has deviated to the outside of the central axis. If we calculate it again at this time, there will be a large error, such as Fig. 14B As shown, when calculating the section 1, the shaded area in the figure will be over-calculated. The greater the deviation from the central axis, the greater the calculation error. Therefore, this algorithm also requires a high level of skill from the operator. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides an automatic bladder volume measuring device.

[0005] A bladder volume automatic measuring device, comprising:

[0006] An ultrasonic probe module, comprising an ultrasonic probe, a probe driving circuit and a probe signal transceiver circuit;

[0007] A microprocessor, connected to the power supply and the FPGA main control processor signal;

[0008] The FPGA control processor is connected to the probe drive circuit and the probe signal transceiver circuit for controlling the ultrasonic probe, ultrasonic imaging and image processing, and performing fast groove edge and volume calculation;

[0009] power supply;

[0010] Input module;

[0011] The FPGA control processor generates a driving signal of the ultrasonic probe to the probe driving circuit according to the instrument start pre-scan or scanning signal sent by the input module, and the probe driving circuit controls the ultrasonic probe to scan and rotate;

[0012] The probe signal transceiver circuit receives the ultrasonic signal reflected by the ultrasonic probe, amplifies and performs A / D conversion, transforms it into a digital signal and transmits it to the FPGA control processor for ultrasonic imaging and image processing, and performs rapid groove edge and volume calculation.

[0013] Furthermore, the microprocessor is a Cofex-A9 processor, which is connected to the FPGA control processor via a control line, an SPI bus and an EIM bus.

[0014] Furthermore, the FPGA control processor is an FPGA programmable logic device, which includes a main control processor, an ultrasound imaging and image processor, and a gradient calculation processor.

[0015] Furthermore, the ultrasonic probe includes a probe module, an upper motor and a lower motor, and the probe module includes a probe wafer and a probe transmitting circuit;

[0016] The lower motor is fixed at the starting position of the scanning range when scanning starts, and the upper motor drives the probe module to swing back and forth within a specified angle range, so that the ultrasonic probe acquires an ultrasonic image of the first section;

[0017] Then, the lower motor rotates to a specified angle and is fixed; the upper motor then swings back and forth within a specified angle range to obtain an ultrasonic image of the second section; this process is repeated until the lower motor rotates to the end position, the upper motor swings back and forth within a specified angle range to obtain an ultrasonic image of the nth section, and then stops.

[0018] Furthermore, the FPGA control processor generates a transmit pulse and outputs it to the probe transmit circuit. The probe transmit circuit amplifies the transmit pulse and sends it to the probe chip. The probe signal transceiver circuit includes an ultrasonic preamplifier circuit and an A / D signal conversion circuit. The ultrasonic preamplifier circuit amplifies the ultrasonic electrical signal transmitted from the probe chip and sends it to the A / D signal conversion circuit to convert it into an ultrasonic digital signal, which is then sent to the ultrasonic imaging and image processor for processing.

[0019] Furthermore, the probe transmitting circuit includes a UCC37323 chip and an amplifier circuit; the transmitting pulse is transmitted to the input end of the UCC37323 chip by the FPGA control processor, and the output end of the UCC37323 chip outputs a signal which is power amplified by the amplifier circuit and then sent to the probe chip for transmission.

[0020] Furthermore, the ultrasonic imaging and image processor performs digital scanning conversion on the received ultrasonic digital signal by adopting a coordinate conversion method of variable angle emission and variable frequency sampling.

[0021] Furthermore, the coordinate transformation method of the variable-angle emission and variable-frequency sampling is to complete the coordinate transformation in the vertical direction during the sampling and storage process of each scanning line, and to complete the coordinate transformation in the horizontal direction during the process of reading data from the memory in sequence row by row.

[0022] Further, the gradient calculation processor performs the gradient calculation by first setting the gradients of the first sampling line and the last sampling line to 0. In the gradient calculation process, the data of the two sampling lines are first saved. When sampling starts from the second sampling line, the gradients of the first sampling point and the last sampling point of the sampling line are first set to 0. Starting from the third sampling point, the horizontal gradient and the vertical gradient of the second sampling point of the second line are calculated; and so on.

[0023] The specific implementation steps of the gradient calculation processor to calculate the horizontal and vertical gradient values ​​of each sampling point of the image are as follows:

[0024] 1). Find the gradient matrix: A frame of ultrasound original image samples 400 points vertically and 201 lines horizontally, such as Figure 5 As shown, we get an original ultrasound data matrix of size 400*201; assuming that the sampling value of the xth point on the yth transmission line (horizontally) is z (x,y) , using Figure 6 The Sobel operator shown is used as the gradient operator in the x direction (vertical direction) and the gradient operator in the y direction (horizontal direction); when the Sobel operator is used to calculate the gradient of the 400*201 area, the value marked as z is obtained. (x,y) The x-direction gradient G of the sampling point x and the gradient G in the y direction y The quantities are:

[0025] G x =(z (x+1,y-1) +2*z (x+1,y) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x-1,y) +z (x-1,y+1) )

[0026] G y =(z (x-1,y+1) +2*z (x,y+1) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x,y-1) +z (x+1,y-1) )

[0027] Marked as z (x,y) The calculation formula of the gradient of the sampling point is

[0028] 2) In threshold processing, the basic global threshold is used: when the gradient value of a pixel (x, y) is ▽f (x,y) When it is greater than or equal to the set threshold T, the gray value of the point is set to 255, otherwise it is 0; that is:

[0029]

[0030] After sampling a frame of image, a 400*201 ultrasound data matrix and a 400*201 gradient data matrix are obtained.

[0031] The present invention also provides a method for measuring bladder volume, comprising the following steps:

[0032] S1, acquiring several images using a 3D ultrasound probe;

[0033] S2, bladder capacity is measured by using a technique that draws the boundary points of the bladder and performs point integration calculations.

[0034] Furthermore, in S2, the boundary data of each cross section of the bladder is obtained by fast outlining according to the image gradient value, and a number of bladder boundary segmentation points are obtained at the same time. The right side curve of the curve of each bladder boundary of the several images obtained by the bladder scan is divided into several segments such as L1, L2, L3, etc. according to the bladder boundary segmentation points. According to the divided segments of the curve, the integral value of one surface in the integral value of the L1 segment curve is first calculated, and the area values ​​corresponding to all points of the L1 segment are added to obtain the volume value corresponding to the L1 segment. Then, the positive and negative judgment of the volume value is made according to the key point of each segment. The accumulated volume values ​​corresponding to all segments are the right side volume of the bladder scan section. Similarly, the volume value of the left side of the image is calculated. The accumulated volume values ​​of the right and left sides are the volume value of a scan section. The three-dimensional volume of all scan sections combined is the volume of the entire bladder. For example, in S2, the boundary data of each cross section of the bladder is obtained by fast outlining according to the image gradient value, and a number of bladder boundary segmentation points are obtained at the same time. The right side curve of the curve of the bladder boundary of each of the 12 images obtained by the bladder scan is divided into L1, L2, L3, L4, and L5 segments according to the bladder boundary segmentation points. According to the segmentation of the curve, the integral value of one surface in the integral value of the L1 segment curve is first calculated, and the area values ​​corresponding to all points of the L1 segment are added to obtain the volume value corresponding to the L1 segment. Then, the positive and negative judgment of the volume value is made according to the key points of each segment L1, L2, L3, L4, and L5. The accumulated volume values ​​corresponding to the L1, L2, L3, L4, and L5 segments are the right side volume of the bladder scan section. Similarly, the volume value of the left side of the image is calculated. The accumulated volume values ​​of the right and left sides are the volume value of a scan section. The calculated three-dimensional volume of the 12 scan sections combined is the volume of the entire bladder. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art descriptions. Obviously, the drawings described below are only some embodiments of the present invention, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0036] Figure 1 and Fig.15 It is a schematic diagram of the structure of the bladder capacity measuring device of the present invention;

[0037] Figure 2 Take 12 image drive pulse waveform diagrams for the upper motor and the lower motor in the present invention;

[0038] Figure 3 This is a pulse waveform diagram of the forward rotation drive of the upper motor in the present invention;

[0039] Figure 4This is a pulse waveform diagram of the reverse drive of the upper motor in the present invention;

[0040] Figure 5 It is a schematic diagram of calculating the horizontal gradient and vertical gradient of the sampling point of the present invention;

[0041] Figure 6 This is a schematic diagram of ultrasonic section sampling of the present invention;

[0042] Figure 7 Schematic diagram of a 3×3 region (Z is the gray value) and Sobel operator of an image of the present invention;

[0043] Figure 8 The improved image edge enhancement block diagram of the present invention;

[0044] Fig. 9 This is a calculation block diagram of the gradient query table of the present invention;

[0045] Fig.10 It is a schematic diagram of the right side curve division of the bladder of the present invention;

[0046] Fig.11 It is a schematic diagram that each curve of the present invention is composed of points;

[0047] Fig.12 It is a schematic diagram of the integration of a surface corresponding to each point of each curve segment of the present invention;

[0048] Fig.13 This is a schematic diagram of the error of the existing large orange peel algorithm in which the central axis deviates but is still within the bladder section;

[0049] Fig.14A and Fig. 14B Schematic diagram of the error caused by the central axis of the existing 3D imaging algorithm deviating outside the bladder section. DETAILED DESCRIPTION

[0050] In order to facilitate the understanding of the present invention, the present invention will be described in more comprehensive and detailed manner in conjunction with the accompanying drawings and preferred embodiments of the specification. However, the protection scope of the present invention is not limited to the following specific embodiments. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0051] In order to achieve the purpose of the present invention, the technical solution provided by the present invention is:

[0052] like Figure 1 and Fig.15 As shown, a bladder volume automatic measuring device comprises:

[0053] An ultrasonic probe module, comprising an ultrasonic probe, a probe driving circuit and a probe signal transceiver circuit;

[0054] A microprocessor, connected to the power supply and the FPGA main control processor signal;

[0055] The FPGA control processor is connected to the probe drive circuit and the probe signal transceiver circuit for controlling the ultrasonic probe, ultrasonic imaging and image processing, and performing fast groove edge and volume calculation;

[0056] power supply;

[0057] Input module; the input module generally includes a scanning button and / or a touch screen (generally provided with a button module).

[0058] The FPGA control processor generates a driving signal of the ultrasonic probe to the probe driving circuit according to the instrument start pre-scan or scanning signal sent by the input module, and the probe driving circuit controls the ultrasonic probe to scan and rotate;

[0059] The probe signal transceiver circuit receives the ultrasonic signal reflected by the ultrasonic probe, amplifies and performs A / D conversion, transforms it into a digital signal and transmits it to the FPGA control processor for ultrasonic imaging and image processing, and performs rapid groove edge and volume calculation.

[0060] In some embodiments, the microprocessor uses a Cofex-A9 processor, which is connected to the FPGA control processor via a control line, an SPI bus, and an EIM bus.

[0061] In some embodiments, the FPGA control processor uses an FPGA programmable logic device, which includes a main control processor, an ultrasound imaging and image processor, and a gradient calculation processor.

[0062] In a specific implementation, the ultrasonic probe includes a probe module, an upper motor and a lower motor, and the probe module includes a probe wafer and a probe transmitting circuit;

[0063] The lower motor is fixed at the starting position of the scanning range when scanning starts, and the upper motor drives the probe module to swing back and forth within a specified angle range (e.g., 120°), and the ultrasonic probe acquires an ultrasonic image of the first section;

[0064] Then, the lower motor rotates to a specified angle (e.g., 15°) and is fixed; the upper motor then swings back and forth within a specified angle range (e.g., 120°) to obtain an ultrasonic image of the second section; this process is repeated until the lower motor rotates to the end position, the upper motor swings back and forth within a specified angle range (e.g., 120°) to obtain an ultrasonic image of the nth section, and then stops.

[0065] Among them, the FPGA control processor generates a transmission pulse and outputs it to the probe transmission circuit. The probe transmission circuit amplifies the transmission pulse and sends it to the probe chip. The probe signal transceiver circuit includes an ultrasonic preamplifier circuit and an A / D signal conversion circuit. The ultrasonic preamplifier circuit amplifies the ultrasonic electrical signal transmitted from the probe chip and sends it to the A / D signal conversion circuit to convert it into an ultrasonic digital signal, which is sent to the ultrasonic imaging and image processor for processing.

[0066] In some embodiments, the probe transmitting circuit includes a UCC37323 chip and an amplifier circuit adapted thereto; the transmitting pulse is transmitted to the input end of the UCC37323 chip by an FPGA control processor, and the output signal of the output end of the UCC37323 chip is power amplified by the amplifier circuit and then sent to the probe chip for transmission.

[0067] Among them, the ultrasonic imaging and image processor digitally scan and transform the received ultrasonic digital signal by using the coordinate transformation method of variable angle emission and variable frequency sampling. In practice, since the scanning imaging method of emission and the scanning imaging display direction of TFT are different, and the imaging speed is also different, in order to realize the real-time imaging of two-dimensional sections, a digital scanning converter (DSC) is designed in the image processing and gradient calculation processing to realize the conversion of ultrasonic emission scanning format into TFT (display) scanning format. We know that the scanning method of ultrasound is mainly divided into linear array and fan-shaped method. The DSC principle of linear array scanning method is relatively simple, and the array elements in its probe emit and receive ultrasonic echoes in sequence. These ultrasonic scanning lines correspond to the column address of the image memory, and the sample points on each scanning line correspond to the row address of the image memory. The sampling values ​​are written into the row address of the image memory in sequence by column, and the data is read out from the memory in sequence by row when displayed. The sector scanning method is preferably used. Since the DSC of the sector scanning method is more complicated and requires coordinate conversion, the polar coordinates of the sector are generally converted into rectangular coordinates through calculation, and the echo information is written into an image memory corresponding to the display pixel according to the given rectangular coordinate address. When displayed, the data is read out from the memory in sequence by line. Although this method is simple, it occupies a large amount of storage resources and has great limitations on image post-processing. The most critical thing is that the storage address of the sample point obtained by this calculation method has accuracy problems, so it is difficult to achieve high-precision interpolation, which directly affects the image quality.

[0068] Therefore, in practical applications, the coordinate transformation method of the variable angle transmission and variable frequency sampling can be considered to complete the coordinate transformation in the vertical direction during the sampling and storage process of each scanning line, and the sampling frequency of each line is different. And the coordinate transformation in the horizontal direction is completed during the process of reading data from the memory in sequence by line. The biggest advantage of using this method is that all echo data are retained, so that the data interpolation link can obtain higher accuracy. The image quality has been greatly improved, but the processing speed is required to be high. The programmable logic device FPGA can be used to implement the coordinate transformation method of variable angle transmission and variable frequency sampling. Another very important function of DSC is to perform some digital image processing and compensation processing. For example: a series of processing such as averaging, enhancement, correlation, gamma correction, digital amplification, detection, logarithmic compression, smooth interpolation of image information, signal bandpass, etc. of image signals are all completed in DSC, and the image is finally displayed on the screen.

[0069] In practical applications, the gradient calculation processor performs gradient calculation by first setting the gradients of the first sampling line and the last sampling line to 0. In the gradient calculation process, the data of the two sampling lines are first saved. When sampling starts from the second sampling line, the gradients of the first sampling point and the last sampling point of the sampling line are first set to 0. Starting from the third sampling point, the horizontal gradient and vertical gradient of the second sampling point of the second line are calculated; and so on; the first sampling line and the last sampling line have little effect on the final overall image gradient, so we set their gradients to 0. The specific implementation of horizontal gradient calculation and vertical gradient calculation is as follows: Figure 4 After obtaining the horizontal gradient and vertical gradient, we need to perform square and square root operations, which are very time-consuming. The advantage of FPGA implementation is that we can obtain the calculation results by querying the table, with almost no delay, which greatly reduces the time of software implementation.

[0070] The specific implementation steps of the gradient calculation processor to calculate the horizontal and vertical gradient values ​​of each sampling point of the image are as follows:

[0071] 1). Find the gradient matrix: A frame of ultrasound original image samples 400 points vertically and 201 lines horizontally, such as Figure 5 As shown, we get an original ultrasound data matrix of size 400*201; assuming that the sampling value of the xth point on the yth transmission line (horizontally) is z (x,y) , using Figure 6 The Sobel operator shown is used as the gradient operator in the x direction (vertical direction) and the gradient operator in the y direction (horizontal direction); when the Sobel operator is used to calculate the gradient of the 400*201 area, the value marked as z is obtained. (x,y) The x-direction gradient G of the sampling point x and the gradient G in the y directiony The quantities are:

[0072] G x =(z (x+1,y-1) +2*z (x+1,y) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x-1,y) +z (x-1,y+1) )

[0073] G y =(z (x-1,y+1) +2*z (x,y+1) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x,y-1) +z (x+1,y-1) )

[0074] Marked as z (x,y The calculation formula of the gradient of the sampling point is

[0075] 2) In threshold processing, the basic global threshold is used: when the gradient value of a pixel (x, y) is ▽f (x,y) When it is greater than or equal to the set threshold T, the gray value of the point is set to 255, otherwise it is 0; that is:

[0076]

[0077] After sampling a frame of image, a 400*201 ultrasound data matrix and a 400*201 gradient data matrix are obtained.

[0078] After the image data and gradient data are processed by hardware interpolation, a frame of ultrasound image data matrix 400*500 and image gradient data matrix 400*500 are obtained. Figure 7 shown.

[0079] From the above formula, we can see that to calculate the gradient value of a sampling point, only 4 shift operations, 8 addition operations, 2 subtraction operations, 2 square operations, and 1 square root operation are required. For FPGA, the addition and subtraction operations are very fast. The square operation and square root operation can be implemented by table lookup method, such as Figure 8 As shown in the figure, the calculation speed is faster than that of software. Since we perform edge enhancement on the data before imaging, the amount of calculation is reduced even more, so the speed is faster.

[0080] Using the above device, we can implement a bladder volume measurement method, including the following steps:

[0081] S1, acquiring several images using a 3D ultrasound probe;

[0082] S2, bladder capacity is measured by using a technique that draws the boundary points of the bladder and performs point integration calculations.

[0083] In S2, the boundary data of each cross section of the bladder is obtained by fast outlining according to the image gradient value, and a number of bladder boundary segmentation points are obtained at the same time. The right side curve of the curve of each bladder boundary of the several images obtained by the bladder scan is divided into several segments such as L1, L2, L3, etc. according to the bladder boundary segmentation points. According to the divided segments of the curve, the integral value of one surface in the integral value of the L1 segment curve is first calculated, and the area values ​​corresponding to all points of the L1 segment are added to obtain the volume value corresponding to the L1 segment. Then, the positive and negative judgment of the volume value is made according to the key points of each segment. The accumulated volume values ​​corresponding to all segments are the right side volume of the bladder scan section. Similarly, the volume value of the left side of the image is calculated. The accumulated volume values ​​of the right and left sides are the volume value of a scan section. The three-dimensional volume of all scan sections combined is the volume of the entire bladder. For example, in S2, the boundary data of each cross section of the bladder is obtained by fast outlining according to the image gradient value, and a number of bladder boundary segmentation points are obtained at the same time. The right side curve of the curve of the bladder boundary of each of the 12 images obtained by the bladder scan is divided into L1, L2, L3, L4, and L5 segments according to the bladder boundary segmentation points. According to the segmentation of the curve, the integral value of one surface in the integral value of the L1 segment curve is first calculated, and the area values ​​corresponding to all points of the L1 segment are added to obtain the volume value corresponding to the L1 segment. Then, the positive and negative judgment of the volume value is made according to the key points of each segment L1, L2, L3, L4, and L5. The accumulated volume values ​​corresponding to the L1, L2, L3, L4, and L5 segments are the right side volume of the bladder scan section. Similarly, the volume value of the left side of the image is calculated. The accumulated volume values ​​of the right and left sides are the volume value of a scan section. The calculated three-dimensional volume of the 12 scan sections combined is the volume of the entire bladder.

[0084] The working principle of the present invention is as follows:

[0085] 1) Main control of the whole machine

[0086] The microprocessor is the main controller of the instrument. It uses the Cofex-A9 processor, which issues instructions to instruct the FPGA control processor (hereinafter referred to as FPGA) as the slave controller to perform a series of control instructions and signals for bladder volume scanning. The FPGA then issues instructions for probe scanning, ultrasonic signal transmission and reception control, ultrasonic imaging, image processing, and gradient calculation processing. At the same time, the acquired bladder scanning image information and image gradient value information are sent to the main control Cofex-A9 processor. The master and slave controllers control each other and communicate with each other, each taking responsibility for completing the work of bladder volume measurement and managing the orderly work of each component of the whole machine.

[0087] 2) Probe scanning control

[0088] This embodiment uses a fan-scanning B-type ultrasonic diagnostic instrument, which uses a mechanical fan-shaped scanning ultrasonic probe and relies on mechanical transmission to drive the sensor to achieve fan-shaped scanning. The fan-scanning B-type ultrasonic diagnostic instrument uses a swinging (rotating) three-dimensional ultrasonic probe directly driven by a three-phase stepper motor. There are two stepper motors in the probe, the lower stepper motor (main motor) rotates 180° along the longitudinal axis, and the upper stepper motor (slave motor) swings back and forth 120°. When the scanning starts, when the lower stepper motor is fixed at the 0° starting position of the 0-180° scanning range, the upper stepper motor swings back and forth 120° to obtain an ultrasonic image. Then the lower stepper motor rotates 15° and is fixed, and the upper stepper motor then rotates 120° to obtain the second image. Next, let the lower stepper motor rotate 15° again, and the upper stepper motor scans again, and so on and so forth until the lower stepper motor rotates 180° and stops. At this time, a total of 13 images are obtained, and 12 of them are used for calculation to calculate the volume of the bladder. The upper stepper motor controls the piezoelectric chip in the probe to swing back and forth 120°. The piezoelectric chip emits an ultrasonic beam while swinging to form an ultrasonic scan. This ultrasonic wave generates a reflected or scattered wave when passing through the tissue interface in the human body. The tissue organ can be located according to its return time, and the characteristics of the tissue can be detected according to its intensity. Emitting a pulse can only obtain information on a certain plane of the tissue. To obtain a two-dimensional planar tissue image, at least 128 times are required, and then the images emitted and received in sequence are displayed on the display screen. The displayed image is the grayscale modulation of the received sound beam signal intensity, and a planar image identical to the actual section is obtained.

[0089] The driving pulse waveforms of the upper stepper motor and the lower stepper motor are shown in Figure 12. Figure 2 and Figure 3 As shown, Figure 1 Take 12 images of driving pulse waveforms for the upper stepper motor and the lower stepper motor; Figure 3 This is the pulse waveform diagram of the forward drive of the upper stepper motor; Figure 4 This is the reverse drive pulse waveform of the upper stepper motor.

[0090] 3) Ultrasonic signal transmission and reception control

[0091] The probe's transmission is based on the probe's inherent frequency. The FPGA control processor generates a transmission pulse with a corresponding pulse width and outputs it to the probe's transmission circuit. The transmission circuit amplifies the transmission pulse and sends it to the probe chip. The probe chip is actually an energy conversion device. Transmission is to convert the transmission pulse (electrical energy) into mechanical energy and then into ultrasonic energy. Reception is to convert ultrasonic energy into mechanical energy and then into electrical energy. Signal reception is the ultrasonic preamplifier circuit amplifying the ultrasonic electrical signal received from the transducer and then sending it to the A / D conversion circuit to convert it into an ultrasonic digital signal and send it to the image processor for processing. The transmission pulse is given by the programmable logic control device FPGA control processor and sent to the input end of the transmission driver UCC37323 chip. The output end of the chip is sent to the power field effect tube for power amplification and then sent to the probe chip for transmission. The probe transmission circuit is composed of a transmission driver chip and field effect tube and other devices. The probe receiving circuit is composed of a preamplifier and an A / D conversion circuit, and the programmable logic control device FPGA control processor gives a control pulse.

[0092] 4) Ultrasonic imaging, image processing and gradient calculation processing

[0093] Ultrasonic imaging and image processing: The received digital ultrasonic signal is digitally scanned and converted. In practice, since the scanning imaging mode of transmission and the scanning imaging display direction of TFT are different, and the imaging speed is also different, in order to realize the real-time imaging of two-dimensional sections, a digital scanning converter (DSC) is designed in the image processing and gradient calculation processing to realize the conversion of ultrasonic transmission scanning format into TFT (display) scanning format. We know that the scanning mode of ultrasound is mainly divided into linear array and fan-shaped mode. The DSC principle of linear array scanning mode is relatively simple, and the array elements in its probe transmit and receive ultrasonic echoes in sequence. These ultrasonic scanning lines correspond to the column address of the image memory, and the sample points on each scanning line correspond to the row address of the image memory. The sampling values ​​are written into the row address of the image memory in sequence by column, and the data is read out from the memory in sequence by row when displayed. Since the present embodiment adopts the sector scanning mode, the DSC of the sector scanning mode is relatively complex and needs to be converted into coordinates. Generally, the polar coordinates of the sector are converted into rectangular coordinates by calculation, and the echo information is written into an image memory corresponding to the display pixel one by one according to the given rectangular coordinate address. When displaying, the data is read out from the memory in sequence by line. Although this method is simple, it occupies a large amount of storage resources and has great limitations on image post-processing. The most critical thing is that the storage address of the sample point obtained by this operation method has an accuracy problem, so it is difficult to achieve high-precision interpolation, which directly affects the image quality. In the device of the present invention, a coordinate transformation method of variable angle emission and variable frequency sampling is adopted, that is, the coordinate transformation in the vertical direction is completed in the process of sampling and storing each scanning line, and the sampling frequency of each line is different. The coordinate transformation in the horizontal direction is completed in the process of reading data from the memory in sequence by line. The greatest advantage of this method is that all echo data are retained, so that the data interpolation link can obtain higher accuracy. The image quality has been greatly improved, but the processing speed is required to be high. We use a programmable logic device FPGA to implement the coordinate transformation method of variable angle emission and variable frequency sampling. Another important function of DSC is to perform some digital image processing and compensation processing. For example, a series of processing such as image signal averaging, enhancement, correlation, gamma correction, digital amplification, detection, logarithmic compression, smooth interpolation of image information, signal bandpass, etc. are all completed in DSC, and finally the image is displayed on the screen.

[0094] Gradient calculation processing: The invention uses hardware to implement gradient calculation in DSC. In gradient calculation, the first sampling line and the last sampling line have little significance for image edge enhancement, so we set their gradients to 0. The first sampling point and the last sampling point of the sampling line have little significance for image edge enhancement, so we also set their gradients to 0. Therefore, in the process of implementing the gradient calculation, we first save the data of 2 sampling lines. When the third sampling line starts sampling, starting from the third sampling point, we can calculate the horizontal and vertical gradients of the second sampling point of the second line. And so on. The first sampling line and the last sampling line have little significance for the final overall image gradient, so we set their gradients to 0. The specific implementation of horizontal gradient calculation and vertical gradient calculation is as follows Figure 5 After obtaining the horizontal and vertical gradients, square and square root operations are required. Square and square root operations are very time-consuming. The advantage of FPGA implementation is that the calculation results can be obtained by querying the table, with almost no delay, which greatly reduces the time of software implementation. Calculate the horizontal and vertical gradient values ​​of each sampling point of the image. The specific implementation steps are:

[0095] 1. Find the gradient matrix: A frame of ultrasound original image samples 400 points vertically and 201 lines horizontally, such as Figure 6 As shown, we get a raw ultrasound data matrix of size 400*201. Assume that the sampling value of the xth point on the yth transmission line (horizontally) is z (x,y) , using Figure 7 The Sobel operator shown is used as the gradient operator in the x direction (vertical direction) and the gradient operator in the y direction (horizontal direction). When the Sobel operator is used to calculate the gradient of the 400*201 area, the value marked as z is obtained. (x,y) The x-direction gradient G of the sampling point x and the gradient G in the y direction y The quantities are:

[0096] G x =(z (x+1,y-1) +2*z (x+1,y) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x-1,y) +z (x-1,y+1) )

[0097] G y =(z (x-1,y+1) +2*z (x,y+1) +z (x+1,y+1) )-(z (x-1,y-1) +2*z (x,y-1) +z (x+1,y-1) )

[0098] Marked as z(x,y) The calculation formula of the gradient of the sampling point is

[0099] 2. In threshold processing, the basic global threshold is used: when the gradient value of a pixel (x, y) is ▽f (x,y) When it is greater than or equal to the set threshold T, the gray value of the point is set to 255, otherwise it is 0. That is:

[0100]

[0101] After sampling a frame of image, we can get a 400*201 ultrasound data matrix and a 400*201 gradient data matrix. After the image data and gradient data are processed by hardware interpolation, we can get a frame of ultrasound image data matrix 400*500 and image gradient data matrix 400*500. Figure 8 shown.

[0102] From the above formula, we can see that to calculate the gradient value of a sampling point, only 4 shift operations, 8 addition operations, 2 subtraction operations, 2 square operations, and 1 square root operation are required. For FPGA, the addition and subtraction operations are very fast. The square operation and square root operation can be implemented by table lookup method, such as Fig. 9 As shown in the figure, the calculation speed is faster than that of software. Since we perform edge enhancement on the data before imaging, the amount of calculation is reduced even more, so the speed is faster.

[0103] The FPGA control processor sends the processed image information and the image gradient value to the Cofex-A9 processor, which performs a fast edge calculation on the bladder image to obtain the bladder boundary data and the key data of the bladder boundary segmentation points.

[0104] 5) Fast edge calculation and bladder volume calculation

[0105] Fast outlining operation: Cofex-A9 processor determines the boundary points of the bladder from bottom to top based on the gradient matrix of the image, starting from the central scan line of an image: after finding the maximum value of the gradient from bottom to top, there are 5 consecutive minimum values ​​of the gradient. The maximum value of this gradient is the lowest wall of the bladder. On the contrary, when the gradient values ​​are all minimum values ​​and then there are 5 consecutive maximum gradient values, the gradient minimum value becomes the maximum value, which is the upper wall of the bladder. In the same way, find the boundary value of the entire bladder image (i.e., the bladder wall) to the left or right. After completing the bladder wall (outlining) operation, determine the turning point of the coordinate change in the X and Y directions of the bladder wall. Regardless of the turning point where the coordinate changes from small to large or from large to small (i.e., the key data of the bladder boundary segmentation point), the Cofex-A9 processor will also obtain the bladder boundary data and the key data of the bladder boundary segmentation point and send it to the internal DDR3 memory for storage.

[0106] 6) Bladder volume calculation: The Cofex-A9 processor calculates the bladder volume based on the bladder boundary data and the key data of the bladder boundary segmentation points by drawing the boundary points while performing point integration operations:

[0107] 1. First, divide the right side of the bladder curve into L1, L2, L3, L4, and L5 according to the key points of the bladder boundary segmentation. Fig.10 shown.

[0108] 2. Calculate the integral system of a surface in the integral value of each segment of the curve. Take segment L1 as an example. The L1 curve consists of points p0 p1 p2 ...p n Composition (such as Fig.11 The area value corresponding to each point is (like Fig.12 As shown), tan15°*i is the length of each line segment, and the sum of their lengths is the area value.

[0109] 3. Add the area values ​​corresponding to all points in segment L1 to get the volume value corresponding to segment L1. The same method is used to obtain V L2 、V L3 、V L4 、V L5 Then the volume value is judged to be positive or negative according to the segment key points (see Fig.10 ) (Below the lowest point A of the central axis, if the curve is in a downward trend, it is negative, and the upward trend is positive. Above the highest point B, the upward trend is negative, the downward trend is positive, and the trend between AB is positive), then the volume value V1 on the right side of the image 右 =-V L1 +V L2 +V L3 +V L4 -V L5 Similarly, calculate the volume value V1 on the left side of the image 左 , then the volume value corresponding to the first image is V1=V1 右 +V1 左 .

[0110] 4. The formula for calculating the volume of the 12 faces combined (i.e. bladder capacity) is: The index is the ratio of the actual size of the bladder section to the image size.

[0111] This invention not only enables bladder volume measurement to break through the single-shape mathematical model, but also solves the problem of over-volume calculation caused by the deviation of the central axis of the flap-type superimposed volume meter, and also solves the problem of over-volume calculation caused by the central axis of the volume meter superimposed according to the ultrasound depth appearing outside the cross-sectional area through 3D imaging, thereby fundamentally ensuring the measurement accuracy of the bladder volume value.

[0112] In order to realize the calculation of bladder volume by point integration method while drawing boundary points, the device invented the hardware implementation of Sobel algorithm, obtained the gradient matrix of each pixel point of the corresponding image (previously implemented by software), and accelerated the calculation speed of bladder volume. In conjunction with this, the Cofex-A9 processor is responsible for drawing boundary points while calculating bladder volume by point integration method. It needs to integrate each pixel point in the bladder into volume (i.e., volume) according to the point integration, and also ensure the speed of volume calculation. In order to meet and ensure the implementation of the algorithm, the present invention adopts a mode of controlling and calculating with Cofex-A9 processor as the main control and FPGA controller as the auxiliary control and image acquisition, realizing the coordinated work of an Android system and an FPGA at the same time, so that the control ability, operation ability and reliability of the whole machine are decisively improved, especially the calculation speed can meet the requirement of drawing boundary points while calculating bladder volume by point integration method, so that the calculation accuracy and mismeasurement and misjudgment are fundamentally changed to the maximum extent.

[0113] The present invention has the following beneficial effects and advantages:

[0114] 1. It can conveniently and painlessly perform accurate quantitative measurement of bladder volume and apply the measurement of bladder volume to a wider range of fields. The present invention adopts an algorithm for measuring bladder capacity by drawing boundary points while performing point integration, which avoids the calculation error caused by the deviation of the image from the central axis during the scanning process of the mechanical probe; and the calculation error caused by the deviation of the image from the central axis during the operation by the operator; it also avoids the calculation error and mismeasurement caused by the central axis appearing outside the section area; the measurement accuracy is more accurate, and the strict requirements on the operator's technique are changed; the most important thing is to avoid that even if the proportion of wrong test results is only 1%, the resulting judgment and diagnosis errors may cause irreparable harm to the patient, such as in the radiotherapy of tumors, as a deformable target organ in bladder cancer or an important organ that affects the target area position in cervical / cervical cancer, the bladder volume and its repeatability have certain changes between each treatment. Changes in bladder volume will cause the target position to move, thereby affecting the distribution of doses in and around the target organs. In order to minimize this effect, a certain bladder volume must be maintained before each radiotherapy. How to control the bladder filling to 350ml during pelvic radiotherapy can avoid the displacement of organs. Therefore, accurate measurement of bladder volume during pelvic radiotherapy can cause minimal damage to normal tissues and achieve the effect of precise radiotherapy. In addition, spinal cord injury is a serious trauma, with about 100,000 new patients worldwide each year. Neurogenic bladder is a common bladder dysfunction after spinal cord injury. It is mostly caused by urination disorders caused by damage to the central or peripheral nerves that control the bladder. In severe cases, it can cause urinary tract infection, vesicoureteral reflux, and renal failure. It is the first cause of late death in patients with paraplegia after spinal cord injury. Therefore, controlling or eliminating urinary tract infection, establishing autonomous urination rhythm, reducing bladder pressure, and protecting kidney function are the ultimate goals of treating neurogenic bladder in paraplegic patients. Experts at home and abroad agree that the use of bladder scanners to guide intermittent catheterization for rehabilitation care and training of patients with neurogenic bladder is the most effective treatment method; in addition, if patients after surgery have a long-term indwelling catheter during the perioperative period. Clinically, after the removal of the urinary catheter, patients sometimes have urine retention, especially those with long-term indwelling urinary catheters. The stimulation of the urethral membrane by the urinary catheter causes inflammatory reaction and edema, resulting in changes in the feeling of bladder filling, or the loss of bladder detrusor tension due to long-term indwelling of the urinary catheter. The incidence of urine retention is significantly increased. Re-indwelling of the urinary catheter may cause local damage to the urethra, increase the patient's pain and the chance of urinary tract infection. Therefore, determining the residual urine volume in the bladder is a complete evaluation method for patients suspected of urinary retention. Urinary incontinence, urinary retention and urinary tract infection are also the most common diseases in the elderly. Accurate quantitative measurement of the residual urine volume after urination of patients provides accurate quantitative basis for medical staff to correctly monitor and diagnose bladder status and evaluate bladder function, changing the original deficiency that the evaluation of bladder function, especially after surgery, was seriously affected.

[0115] 2. Eliminate the harm to patients caused by mismeasurement and misjudgment, and reduce the pain of patients. The device and method of the present invention can be used to perform quantitative catheterization on patients who need catheterization, which changes the original open catheterization or catheterization based on the patient's urine storage feeling and the experience of medical staff, thereby reducing iatrogenic urinary tract infections and the pain of frequent catheterization. In addition, since the present invention does not have strict requirements on the operator's technique, in addition to being able to meet the needs of the pelvic radiotherapy process in terms of measurement accuracy, the most critical thing is to avoid damage to the human internal organs during the radiotherapy process caused by mismeasurement and misjudgment, so that the bladder filling can be well controlled during the pelvic radiotherapy process, achieving accurate radiotherapy, reducing the damage to the patient's normal tissues during the radiotherapy process, and significantly reducing the radiotherapy reaction, significantly improving the efficacy of radiotherapy, and reducing a series of pain and organ damage caused by ordinary radiotherapy to patients.

[0116] 3. Rapidly and accurately detect bladder volume values ​​and improve the work efficiency of medical staff. The improved Sobel algorithm used to speed up the calculation of bladder capacity is implemented using FPGA hardware. The gradient value matrix of the ultrasound image is obtained while obtaining the ultrasound imaging matrix, and the software method is used to combine the image and gradient to quickly obtain the bladder calculation results.

[0117] The bladder volume measurement not only breaks through the single shape mathematical model, but also solves the problem of over-counting of volume caused by the deviation of the central axis of the flap-type superimposed volume meter, and also solves the problem of over-counting of volume caused by the central axis of the volume meter superimposed according to the ultrasound depth through 3D imaging appearing outside the cross-sectional area, thereby fundamentally ensuring the measurement accuracy of the bladder volume value.

[0118] 4. Rapidly and accurately measure the bladder volume value automatically to improve the work efficiency of medical staff. Due to the use of a variety of image processing technologies and algorithms, the device can automatically and quickly calculate the bladder volume value in the ultrasound image. This invention breaks through the defect that the bladder capacity measuring instrument in the world does not have the function of automatic calculation of bladder volume, so that the bladder capacity measuring instrument not only has the function of catheterization, but also enables doctors to detect the disease early through the thickness measurement of the bladder wall and has the function of auxiliary diagnosis. And it enables patients to diagnose and treat early, reducing their physical pain and financial pressure. In addition, it solves the operational complexity and precision inaccuracy of the previous manual measurement of bladder volume by B-ultrasound. At the same time, the ultrasonic principle is used to replace the previous CT examination of bladder wall thickening measurement method, which solves the problem of certain radiation caused to the human body by CT examination and measurement.

[0119] 5. The device can use the Android operating platform, and the Android operating system and FPGA work in parallel inside the device. The FPGA chip with dual-core CPU is selected to ensure that the technology of drawing the boundary points of the bladder while performing point integration calculations to measure the bladder capacity can be realized. The operator can easily perform system settings, patient information input, image display, key function operations, information storage, printing, and information management on the Android APP. The Android operating system is used as the main control and calculation, and the core of the large-scale programmable logic device FPGA is used as the slave control in the device. The master-slave control improves the calculation, control ability and operation reliability of the whole machine, and the calculation speed of the system has been fundamentally improved. The instrument realizes the functions of fast and automatic bladder capacity measurement and bystander wall thickness measurement.

[0120] The above embodiments are only for illustrating the technical concept and features of the present invention. The purpose is to enable ordinary technicians in the field to understand the content of the present invention and implement it, and it cannot be used to limit the scope of protection of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the scope of protection of the present invention.

Claims

1. A bladder volume automatic measuring device, characterized in that: include: An ultrasonic probe module, comprising an ultrasonic probe, a probe driving circuit and a probe signal transceiver circuit; A microprocessor, connected to the power supply and the FPGA main control processor signal; The FPGA main control processor is connected to the probe drive circuit and the probe signal transceiver circuit, and is used to control the ultrasonic probe, ultrasonic imaging and image processing, and perform fast groove edge and volume calculation; power supply; Input module; The FPGA main control processor generates a driving signal of the ultrasonic probe to the probe driving circuit according to the instrument start pre-scan or scanning signal sent by the input module, and the probe driving circuit controls the ultrasonic probe to scan and rotate; The probe signal transceiver circuit receives the ultrasonic signal reflected by the ultrasonic probe, amplifies and performs A / D conversion, transforms it into a digital signal and transmits it to the FPGA main control processor for ultrasonic imaging and image processing, and performs rapid groove edge and volume calculation.

2. The automatic bladder volume measuring device according to claim 1, characterized in that: The microprocessor is a Cofex-A9 processor, which is connected to the FPGA main control processor through a control line, an SPI bus and an EIM bus.

3. The automatic bladder volume measuring device according to claim 1, characterized in that: The FPGA main control processor is an FPGA programmable logic device, which includes a main control processor, an ultrasound imaging and image processor, and a gradient calculation processor.

4. The automatic bladder volume measuring device according to claim 3, characterized in that ,The ultrasonic probe includes a probe module, an upper motor and a lower motor, and the probe module includes a probe wafer and a probe transmitting circuit; The lower motor is fixed at the starting position of the scanning range when scanning starts, and the upper motor drives the probe module to swing back and forth within a specified angle range (120°), and the ultrasonic probe obtains an ultrasonic image of the first section; Then, the lower motor rotates to a specified angle and is fixed; the upper motor then swings back and forth within a specified angle range to obtain an ultrasonic image of the second section; this process is repeated until the lower motor rotates to the end position, the upper motor swings back and forth within a specified angle range to obtain an ultrasonic image of the nth section, and then stops.

5. The automatic bladder volume measuring device according to claim 4, characterized in that The FPGA main control processor generates a transmit pulse and outputs it to the probe transmit circuit. The probe transmit circuit amplifies the transmit pulse and sends it to the probe chip. The probe signal transceiver circuit includes an ultrasonic preamplifier circuit and an A / D signal conversion circuit. The ultrasonic preamplifier circuit amplifies the ultrasonic electrical signal transmitted from the probe chip and sends it to the A / D signal conversion circuit to convert it into an ultrasonic digital signal, which is then sent to the ultrasonic imaging and image processor for processing.

6. The automatic bladder volume measuring device according to claim 5, characterized in that The probe transmitting circuit includes a UCC37323 chip and an amplifier circuit; the transmitting pulse is transmitted to the input end of the UCC37323 chip by the FPGA main control processor, and the output signal of the output end of the UCC37323 chip is amplified by the amplifier circuit and then sent to the probe chip for transmission.

7. The automatic bladder volume measuring device according to claim 5, characterized in that The ultrasonic imaging and image processor performs digital scanning transformation on the received ultrasonic digital signal by adopting the coordinate transformation method of variable angle transmission and variable frequency sampling; the coordinate transformation method of variable angle transmission and variable frequency sampling completes the coordinate transformation in the vertical direction during the sampling and storage process of each scanning line, and completes the coordinate transformation in the horizontal direction during the process of reading data from the memory row by row.

8. The automatic bladder volume measuring device according to claim 7, characterized in that The gradient calculation processor performs the gradient calculation by first setting the gradients of the first sampling line and the last sampling line to 0. When sampling starts from the second sampling line, the gradients of the first sampling point and the last sampling point of the sampling line are first set to 0. Starting from the third sampling point, the horizontal gradient and vertical gradient of the second sampling point of the second line are calculated; and so on. The specific implementation steps of the gradient calculation processor to calculate the horizontal and vertical gradient values ​​of each sampling point of the image are as follows: 1) Find the gradient matrix: A frame of ultrasound original image samples 400 points vertically and 201 lines horizontally, as shown in Figure 5, we get an original ultrasound data matrix of size 400*201; Assume that the sampling value of the xth point on the yth transmission line (vertical direction) is z (x,y) , the Sobel operator shown in Figure 6 is used as the gradient operator in the x direction (vertical direction) and the gradient operator in the y direction (horizontal direction); when the Sobel operator is used to calculate the gradient of the 400*201 area, the value marked as z is obtained. (x,y) The x-direction gradient G of the sampling point x and the gradient G in the y direction y The quantities are: G x =(from (x+1,y-1) +2*z (x+1,y) +with (x+1,y+1) )-(With (x-1,y-1) +2*z (x-1,y) +with (x-1,y+1) ) G y =(from (x-1,y+1) +2*z (x,y+1) +from (x+1,y+1) )-(With (x-1,y-1) +2*z (x,y-1) +from (x+1,y-1) ) Marked as z (x,y) The calculation formula of the gradient of the sampling point is 2) When thresholding, use the basic global threshold: when the gradient value of a pixel (x, y) When it is greater than or equal to the set threshold T, the gray value of the point is set to 255, otherwise it is 0; that is: After sampling a frame of image, a 400*201 ultrasound data matrix and a 400*201 gradient data matrix are obtained.

9. A method for measuring bladder volume, characterized in that: The following steps are involved: S1, acquiring several images using a 3D ultrasound probe; S2, bladder capacity is measured by using a technique that draws the boundary points of the bladder and performs point integration calculations.

10. The method for measuring bladder volume according to claim 9, characterized in that: In S2, the boundary data of each cross section of the bladder is obtained by fast outlining according to the image gradient value, and a number of bladder boundary segmentation points are obtained at the same time. The right side curve of the curve of each bladder boundary of the several images obtained by the bladder scan is divided into several segments such as L1, L2, L3, etc. according to the bladder boundary segmentation points. According to the divided segments of the curve, the integral value of one surface in the integral value of the L1 segment curve is first calculated, and the area values ​​corresponding to all points of the L1 segment are added to obtain the volume value corresponding to the L1 segment. Then, the positive and negative judgment of the volume value is made according to the key points of each segment. The accumulated volume values ​​corresponding to all segments are the right side volume of the bladder scan section. Similarly, the volume value of the left side of the image is calculated. The accumulated volume values ​​of the right and left sides are the volume value of a scan section. The three-dimensional volume of all scan sections combined is the volume of the entire bladder.

Images