A method for calculating urine volume in bladder by B-mode ultrasound measurement

Abstract

The present invention discloses a method for calculating the urine capacity in the bladder by measuring with B-type ultrasound. The urine capacity in the bladder is calculated by calculating the bladder volume. The ultrasound acquisition area is cut into 256 horizontal sections from top to bottom, and the spacing between each horizontal section is d and the total depth is d×256. Each horizontal section is further divided into 24 sectors, and the bladder in each sector is expanded into a circle with the current bladder radius as the radius. This circle is used as the base, and a standard cylinder is formed with the horizontal section above. The volume of a single cylinder is calculated, and the volume enclosed by the bladder area in all 24 sectors and the previous horizontal section is summed, that is, the volume enclosed by the bladder area on the current horizontal section as the base and the previous horizontal section, and the volume of a small bladder is obtained. Then the volume of 256 small bladders is summed to obtain the total bladder volume.

Description

Technical Field

[0001] The invention discloses a method for calculating urine volume in bladder, belongs to the technical field of B-type ultrasonic measurement, and specifically discloses a method for calculating urine volume in bladder by B-type ultrasonic measurement. Background Art

[0002] The bladder urine volume measuring instruments currently on the market generally have a large error between the urine volume measurement and the actual measurement results. The main reason is that there are problems with the method of calculating the bladder volume. The urine volume calculation of the urine volume measuring instruments currently on the market basically adopts ellipsoidal volume algorithms or various empirical formulas. For example, the Chinese patent with publication number CN101919713B calculates the upper and lower diameters H and the anterior and posterior diameters D of the bladder based on the transmitted and returned ultrasonic information, and then calculates the bladder urine volume according to the formula V=D×H×K, where K is the correction factor determined by the degree of bladder filling. For example, in the paper "Ultrasonic Measurement of Bladder Urine Volume and Catheterization Treatment Experience of Patients with Urinary Pig Retention" (Minimally Invasive Medicine, 2015, 10(2):3.), the method of calculating the urine volume in the bladder during ultrasound measurement is: obtain the maximum three perpendicular diameter lengths d1, d2, d3 on the maximum cross-section and maximum longitudinal section of the bladder through ultrasound, and use the empirical formula V=0.5d1×d2×d3 to obtain the urine volume value in the bladder. For example, in the paper "Research and Design of Portable Type B Ultrasonic Bladder Volume Measuring Instrument" (Li Zaiyuan, Chang'an University), an improved ellipsoid volume formula V = 0.85 × Sh × Sv / a is used, where Sh represents the maximum area of ​​the bladder cross section, Sv represents the maximum area of ​​the bladder longitudinal section, and a represents the ultrasonic detection depth in bladder detection. However, when measuring the bladder in practice, if the bladder of different people and the amount of urine are different, there will inevitably be problems if the volume of the ellipsoid or other single empirical formula is used for calculation. The more irregular the bladder shape, the greater the error. Summary of the invention

[0003] In order to overcome the problem of large measurement errors in the prior art, the present invention provides a method for calculating the urine volume in the bladder by B-type ultrasound measurement. The method can obtain the correct volume for bladders of different shapes and reduce the measurement error.

[0004] The present invention is implemented by the following technical scheme: a method for calculating the urine volume in the bladder by measuring the urine volume in the bladder by B-type ultrasound, and the specific steps are as follows:

[0005] S1. Use a mechanical fan-scanning ultrasound transmitter probe to collect bladder images.

[0006] S2. Cut the ultrasound acquisition area into 256 horizontal slices from top to bottom, with a spacing of d between each horizontal slice and a total depth of d×256. Divide each horizontal slice into 24 sectors. Since the bladder area is irregular in shape in each horizontal slice, not a standard circle, the radius in different sectors is different. Expand the bladder in each sector into a circle with the current bladder radius as the radius. With this circle as the base, form a standard cylinder with the horizontal slice above. The volume of the cylinder is expressed as V1. Since a single sector is a circle, The bladder area in this sector is the base, and the volume enclosed by the previous horizontal section is the volume of a single sector of the horizontal section.

[0007] S3. Sum the volumes of the bladder regions in all 24 sectors and the previous horizontal section, that is, the volume of the bladder region on the current horizontal section as the base and the previous horizontal section, that is, the volume of one small piece of bladder; a total of 256 small pieces of bladder volume.

[0008] S4. The total bladder volume V is obtained by summing up the volumes of the 256 small bladders. The calculation formula is:

[0009]

[0010] Where: d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

[0011] Furthermore, the calculation formula of the total bladder volume V is obtained by the following method:

[0012] (1) First, calculate the radius information of the bladder in each sector area on all horizontal sections: the radius r of the bladder on the sector is the distance between the center line of the two-dimensional swing motor, that is, the 64th scanning line, and the bladder boundary, that is, the length r from the center line to the bladder boundary of the corresponding sector starting edge in the horizontal section. If there is no bladder boundary information in a certain horizontal section, r = 0;

[0013] (2) Calculate the volume of the bladder region of a single sector in the horizontal section and the horizontal section above:

[0014]

[0015] (3) Calculate the volume of the bladder region enclosed by the 24 sectors in the horizontal section and the horizontal section above:

[0016]

[0017] (4) Calculate the total volume of the bladder: First calculate the volume of the bladder in all sectors of the first horizontal slice and the horizontal slice above, and then obtain the volume of the small bladder on the first horizontal slice. Similarly, calculate the volume of the bladder in all adjacent horizontal slices, add them up, and obtain the volume of the entire bladder Vtotal. The calculation formula is:

[0018]

[0019] Where: d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

[0020] Furthermore, the method for collecting bladder images is: before the detection begins, the patient lies flat, and a special ultrasound coupling agent is applied to the skin 3 cm above the patient's pubic bone, and the ultrasound transmitting probe is placed there, and the scan button is pressed, the two-dimensional motor starts to swing, and the probe direction is slightly adjusted until the bladder cross section can be completely seen and the bladder cross section is centered. The two-dimensional motor swings from left to right to collect images, and no image collection is performed from right to left. At this time, image processing and display operations are performed; then the scan button is pressed again, and the two-dimensional motor and the three-dimensional motor work simultaneously. The three-dimensional motor rotates 15° when the two-dimensional motor swings from right to left; then after the two-dimensional motor swings to the leftmost side, the second image is collected until all 12 images are collected; the probe is kept still until the scan is completed, and 12 usable bladder images similar to the vertical cross-section images of the bladder are obtained.

[0021] The main innovation of the present invention lies in measuring the urine capacity in the bladder by measuring the bladder volume and the bladder volume measuring method.

[0022] The beneficial effect of the present invention is as follows: compared with the prior art, the more complex the bladder shape is when measuring the urine capacity in the human bladder, the greater the error is. When the urine capacity is less than 100ml, the error value is generally around ±15ml, and when the urine capacity is greater than 100ml, the error is generally around 15%. If the bladder shape is particularly complex, the error value may even exceed 30%. When the present invention measures the urine capacity in the human bladder, regardless of the bladder shape, when the urine capacity is less than 100ml, the error value is within ±5ml; when the urine capacity is greater than 100ml, the error value is within ±5%, and the measurement result is more accurate and consistent.

[0023] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a vertical section of the bladder;

[0025] Figure 2 It is a horizontal section of the bladder;

[0026] Figure 3 It is a top view of the rotation of the three-dimensional rotating motor;

[0027] Figure 4 The B-mode ultrasound used to collect bladder images is a schematic diagram of a mechanical fan-scanning ultrasound transmitting probe;

[0028] Figure 5 It is an operation flow chart. DETAILED DESCRIPTION

[0029] In order to enable those skilled in the art to more clearly understand the technical solution and operation method of the present invention, the technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Figure 5 Flowchart shown.

[0030] The B-mode ultrasound used in the present invention to collect bladder images is a mechanical fan-scan ultrasound transmitting probe with two motors, wherein the two-dimensional swing motor swings 128°, with each 1° being a step. Figure 1 As shown in the vertical section of the bladder, one swing has 128 steps, that is, the entire scanning surface has 128 scanning lines; the three-dimensional rotation motor rotates 180°, with each 15° being a step. Figure 3 As shown in the top view of the three-dimensional rotating motor, two fan-shaped areas can be obtained for each step, with a total of 12 steps and 24 fan-shaped areas. From section 1 to section 12, there are 12 available bladder images in one scanning cycle, with the first and seventh images being perpendicular to each other, the second and eighth images being perpendicular to each other, and so on.

[0031] The specific operation method for collecting bladder images is as follows: Figure 4 As shown, Figure 4 The left half of the picture is a schematic diagram of the detection from the right side of the patient, and the right half is a schematic diagram of the detection from the patient's footsteps; because the bladder is located in the lower abdomen of the human body, below the pubic bone. Before the test begins, apply the ultrasound coupling agent to the skin 3 cm above the patient's pubic bone. The patient lies flat, and the ultrasound transmitter probe is placed here. Press the scan button, and the two-dimensional motor starts to swing. Figure 4 As shown in the figure, slightly adjust the probe direction according to the actual situation until the bladder cross section can be fully seen and the bladder cross section is centered, as shown in the figure. Figure 1 As shown in the vertical section of the bladder, the 2D motor swings from left to right to collect images, and does not collect images from right to left. At this time, other operations such as image processing and display are performed. Then press the scan button again. At this time, the 2D motor and the 3D motor work simultaneously. The 3D motor rotates 15° when the 2D motor swings from right to left, which does not affect image collection. Then, after the 2D motor swings to the far left, the second image is collected, until all 12 images are collected. Keep the probe still until the scan is completed, and you can get 12 images. Figure 1The vertical section of the bladder shown is similar to available bladder images.

[0032] The ultrasound acquisition area is cut into 256 horizontal slices from top to bottom, with a spacing of d between each horizontal slice and a total depth of d×256. Each horizontal slice is then divided into 24 sectors. Because the bladder area is an irregular shape in each horizontal slice, not a standard circle, the radius in different sectors is different, such as Figure 2 The horizontal section of the bladder is shown in r1, r13, r2, r14, etc. The bladder in each sector is expanded into a circle with the current bladder radius as the radius, with this circle as the base, and the horizontal section above forms a standard cylinder, and the volume of the cylinder is expressed as V1. Then the volume enclosed by the bladder area in this sector and the previous horizontal section is

[0033] The volume of the bladder area in all 24 sectors and the previous horizontal section is summed up, that is, the volume of the bladder area on the current horizontal section and the previous horizontal section, that is, the volume of one small bladder. Then, the bladder volume calculation formula is used to sum up the volumes of the 256 small bladders to obtain the total bladder volume V.

[0034]

[0035] Where d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

[0036] The bladder volume calculation formula is derived as follows:

[0037] The formula for the volume of a known cylinder is: V = S 底面积 ×d 高 =π*r 2 *d,

[0038] First, find out the radius r of the bladder in each sector area on all horizontal sections: the radius r of the bladder on the sector is the distance from the center line of the two-dimensional swing motor, that is, the 64th scanning line, to the bladder boundary, such as Figure 1 The vertical section of the bladder shows r1, r13, r1', etc. Figure 3 The r1, r4, r16, r24, etc. shown in the top view of the three-dimensional rotating motor, such as the r1, r13, r2, r14, etc. shown in the horizontal section of the bladder; that is, the length of the corresponding fan starting edge from the center line to the bladder boundary in the horizontal section. If there is no bladder boundary information in a horizontal section, r = 0, such as the vertical section of the bladder Figure 1 Then find the volume of the bladder region of a single sector in the horizontal section and the volume enclosed by the horizontal section above Then calculate the volume of the bladder area of ​​the 24 sectors in the horizontal section and the horizontal section above: j indicates that the bladder is in the jth sector; then the total volume of the bladder is calculated: first calculate the volume of the bladder in all sectors of the first horizontal section and the horizontal section above, and the volume of the small bladder on the first horizontal section is obtained, and so on. Calculate the volume of the bladder in all adjacent horizontal sections, and add them up to get the algorithm formula for the volume of the entire bladder:

[0039]

[0040] Where d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

[0041] Specific implementation steps in the code based on the formula:

[0042] (1) Data cache: The acquired bladder images are cached in an external SRAM, occupying an address space of 256*128*12, 256 points in depth*128 scan lines*12 vertical slices.

[0043] (2) Find the radius information of the bladder in each sector:

[0044] The radius information of two sectors can be obtained at the intersection of each vertical and horizontal section. For example, in the horizontal section of the bladder, vertical section 1 intersects with this horizontal section to obtain r1 and r13, vertical section 2 intersects with this horizontal section to obtain r2 and r14, and so on to obtain 24 sector radii.

[0045] The specific method is: for the 128 scanning lines of each vertical section of the bladder, the 128 points that intersect with the corresponding horizontal section at different depths are processed by the bladder boundary detection related algorithm, and the obtained boundary information is the corresponding radius information.

[0046] The process is as follows: starting from the first horizontal section: the first point of the first scan line, the first point of the second scan line, ..., the first point of the 128th scan line, a total of 128 points, complete the bladder boundary detection where the first vertical section intersects with this horizontal section; then repeat the operation of the bladder boundary detection where the first vertical section intersects with this horizontal section, complete the bladder boundary detection where the remaining 11 vertical sections intersect with this horizontal section, and you can get 24 boundary information on the current horizontal section. Then continue with the bladder boundary detection of the second horizontal section, process the second point of all scan lines, and so on.

[0047] Complete edge detection for all horizontal slices.

[0048] The cache is stored in the internal RAM, and the address space occupied is 24*256, that is, 24 radius information of each horizontal slice * 256 horizontal slices.

[0049] (3) Optimizing radius information: The cached bladder boundary information is further processed jointly, and outliers are eliminated to optimize the bladder boundary to obtain more accurate radius information, which is cached in the internal RAM, occupying an address space of 24*256.

[0050] (4) Calculate the volume: Read the radius information from the RAM and use it in the above bladder volume formula to calculate the bladder volume.

[0051] The following experimental examples further verify the effect of the method of the present invention:

[0052] Experimental Example 1: Human Bladder Phantom Test

[0053] Table 1. Human bladder phantom test.

[0054]

[0055]

[0056] 1. Verify the 20ml volume measurement accuracy.

[0057] Table 2: Using a 20 mL ellipsoidal target of the human bladder phantom KS215BP-1, the actual value V0=20 ml.

[0058]

[0059] 2. Verify the 99ml volume measurement accuracy.

[0060] Table 3. Using the 99 mL ellipsoidal target of the human bladder phantom KS215BP-1, the actual value V0=99 ml.

[0061]

[0062] 3. Verify the 137ml volume measurement accuracy.

[0063] Table 4: Using a 137 mL ellipsoidal target of the human bladder phantom KS215BP, the actual value V0 = 137 ml.

[0064]

[0065] Experimental Example 2: Human Bladder Test

[0066] Table 5

[0067] Serial number Name Test value Catheterization actual value Deviation value 1 Participant 1 423 411 2.9％ 2 Participant 2 507 520 -2.5％ 3 Participant 3 389 404 -3.7％ 4 Participant 4 309 323 -4.3％ 5 Participant 5 314 301 4.3％ 6 Participant 6 370 355 4.2％ 7 Participant 7 254 246 3.3％ 8 Participant 8 428 411 4.1％ 9 Participant 9 480 499 -3.8％ 10 Participant 10 396 400 -1.0％

[0068] The actual sample tests of the above two experimental examples show that no matter what the bladder shape is, when the urine volume is less than 100ml, the error value is within ±5ml; when the urine volume is greater than 100ml, the error value is within ±5%, and the measurement results are more accurate and consistent.

Claims

1. A method for calculating the urine volume in the bladder by B-mode ultrasound measurement, characterized in that The urine volume in the bladder is calculated by calculating the bladder volume. The specific method is as follows: S1, using a mechanical fan-scanning ultrasound transmitter probe to collect bladder images; S2. Cut the ultrasound acquisition area into 256 horizontal slices from top to bottom, with a spacing of d between each horizontal slice and a total depth of d×256. Divide each horizontal slice into 24 sectors. Because the bladder area is irregular in shape in each horizontal slice, not a standard circle, the radius in different sectors is different. Expand the bladder in each sector into a circle with the current bladder radius as the radius, with this circle as the base, and form a standard cylinder with the horizontal slice above. The volume of the cylinder is expressed as V1. Because a single sector is a circle, The volume enclosed by the bladder area in this sector and the previous horizontal section is S3, summing the volume of the bladder area in all 24 sectors and the previous horizontal section, that is, the volume of the bladder area on the current horizontal section as the base and the previous horizontal section, to obtain the volume of one small piece of bladder; a total of 256 small pieces of bladder volume; S4. Sum the volumes of the 256 small bladders to obtain the total bladder volume V, which is calculated as follows: Where: d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

2. The method for calculating the urine volume in the bladder by B-type ultrasound measurement according to claim 1, characterized in that The mechanical fan-sweep ultrasound transmitter probe used has two motors.

3. The method for calculating the urine volume in the bladder by B-type ultrasound measurement according to claim 1, characterized in that The method of collecting bladder images in step S1 is: Before the test begins, the patient lies flat, and a special ultrasound coupling agent is applied to the skin 3 cm above the patient's pubic bone. The ultrasound transmitting probe is placed there, and the scan button is pressed. The two-dimensional motor starts to swing, and the probe direction is slightly adjusted until the bladder cross section can be fully seen and the bladder cross section is centered. The two-dimensional motor swings from left to right to collect images, and no image collection is performed from right to left. At this time, image processing and display operations are performed; then the scan button is pressed again, and the two-dimensional motor and the three-dimensional motor work simultaneously. The three-dimensional motor rotates 15° when the two-dimensional motor swings from right to left; then after the two-dimensional motor swings to the leftmost side, the second image is collected, until all 12 images are collected; keep the probe still until the scan is completed, and 12 usable bladder images similar to the vertical cross-section images of the bladder are obtained.

4. The method for calculating the urine volume in the bladder by B-type ultrasound measurement according to claim 1, characterized in that The total bladder volume V is obtained as follows: ① First, find out the radius information of the bladder in each sector area on all horizontal sections: the radius r of the bladder on the sector is the distance from the center line of the two-dimensional swing motor, that is, the 64th scanning line, to the bladder boundary, that is, the length r from the center line to the bladder boundary of the corresponding sector starting edge in the horizontal section. If there is no bladder boundary information in a certain horizontal section, r = 0; ② Calculate the volume V1 enclosed by the single sector bladder area in the horizontal section and the upper horizontal section: ③ Calculate the volume of the 24 sectors of the bladder area in the horizontal section and the upper horizontal section: j indicates that the bladder is in the jth sector; ④ Calculate the total volume of the bladder: First calculate the volume of the bladder in all sectors of the first horizontal section and the horizontal section above, and get the volume of the small bladder on the first horizontal section. And so on; calculate the volume of the bladder in all adjacent horizontal sections, add them up, and get the volume V of the whole bladder. Calculation formula: Where: d is the distance between adjacent horizontal slices, r ij is the radius of the jth sector of the bladder on the i-th horizontal section.

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