Measurement device

Abstract

To improve the accuracy of drop detection in a drip tube and an accuracy of volume estimation related to the detected drop.SOLUTION: A measurement device includes: an instillation probe which has a light source and an image sensor facing each other, irradiates, when attached to the instillation cylinder, the instillation cylinder with the light from the light source, and images an image of the instillation cylinder by the image sensor; and a controller which sequentially obtains the image imaged by the instillation probe, and assuming that a specific region in each obtained image is a first region and another specific region positioned below the first region is a second region, when it is detected, in a time order manner, a first intensity change in the first region and a second intensity change corresponding to the first intensity change in the second region, it is determined that the drop image containing a falling drop is obtained, estimates a volume of the falling drop using the drop image, and calculates a flow rate of the instillation cylinder based on the obtained estimation result.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a measurement device. [Background technology]

[0002] Patent Documents 1 to 4 disclose devices for calculating the flow rate of a drip tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2017-072497 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-148962 [Patent Document 3] Japanese Patent Application Publication No. 2020-185118 [Patent Document 4] International Publication No. 2020 / 070953 Summary of the Invention [Problem to be solved by the invention]

[0004] The volume of a droplet varies depending on various factors, such as the type of liquid, flow rate, temperature, and installation state. In order to improve the accuracy of the flow rate when estimating the volume of a droplet and calculating the flow rate of the drip tube based on the estimated result, it is important to improve the accuracy of the volume estimation or the droplet detection in the previous stage.

[0005] An object of the present disclosure is to improve the accuracy of droplet detection in a drip cylinder or volume estimation for detected droplets. [Means for solving the problem]

[0006] Some aspects of the present disclosure are set forth below.

[0007] [1] An infusion probe having a light source and an image sensor facing each other, which, when attached to an infusion tube, irradiates the infusion tube with light from the light source and captures an image of the infusion tube with the image sensor; a controller that sequentially acquires images taken by the drip probe, defines a specific region of each acquired image as a first region, and defines another specific region located below the first region as a second region, and determines that a droplet image including a falling droplet has been obtained by detecting a first luminance change in the first region and a second luminance change in the second region corresponding to the first luminance change in the second region in time sequence, estimates the volume of the falling droplet using the droplet image, and calculates the flow rate of the drip tube based on the estimated result; A measuring device comprising:

[0008] [2] The measuring device described in [1], wherein the controller detects peaks that appear in the waveform of the difference between the brightness of the first region and the second region and the moving average of the brightness of the first region and the second region within a certain period going back from the time of acquisition of the corresponding image as the first brightness change and the second brightness change, respectively.

[0009] [3] The measuring device according to [2], wherein the controller issues a warning when it determines that the peak corresponding to the first luminance change and the peak corresponding to the second luminance change are inseparable.

[0010] [4] The measuring device according to any one of [1] to [3], wherein the controller uses an image from which the first luminance change is detected as the droplet image.

[0011] [5] The infusion probe further comprises an angle sensor; The measuring device described in any of [1] to [4], wherein when the controller detects the inclination of the infusion probe relative to the direction of gravity using the angle sensor, it rotates each acquired image according to the detected inclination, and then determines whether the droplet image has been obtained.

[0012] [6] The measuring device according to any one of [1] to [5], wherein the controller extracts the contour of the falling droplet from the droplet image, estimates the volume based on the extracted result, and, when one or more defects in the contour are detected, interpolates the one or more defects before estimating the volume.

[0013] [7] The measuring device according to [6], wherein when the controller detects a defect on one side of the body as the one or more defects, the controller symmetrically interpolates the defect on the one side of the body.

[0014] [8] The measuring device according to [6] or [7], wherein when the controller detects defects on both the left and right sides that are in the same vertical position as the one or more defects, it linearly interpolates the defects on both the left and right sides.

[0015] [9] The measuring device according to any one of [6] to [8], wherein the controller issues a warning when it determines that the vertical length of the contour satisfies a warning condition.

[0016]

[10] The measuring device according to any one of [6] to [9], wherein the controller issues a warning when it determines that the shape of the contour satisfies a warning condition.

[0017]

[11] A measuring device described in any of [6] to

[10] , wherein when the controller determines that the defect rate of the contour exceeds a threshold, instead of estimating the volume, it applies an estimation result obtained using one or more other droplet images obtained before the droplet image was acquired.

[0018]

[12] When the controller determines that the defect rate of the contour exceeds a threshold, the controller vibrates the drip tube of the drip probe to remove droplets adhering to the inner surface of the drip probe. [6] to

[11] A measuring device described in any one of

[11] to

[11] .

[0019]

[13] When the controller determines that the defect rate of the contour exceeds a threshold value, it causes the drip probe to emit ultrasonic waves into the drip tube to remove droplets adhering to the inner surface of the drip probe. A measuring device described in any of [6] to

[12] .

[0020]

[14] An infusion probe having a light source and an image sensor facing each other, which, when attached to an infusion tube, irradiates the infusion tube with light from the light source and captures an image of the infusion tube with the image sensor; A controller that sequentially acquires images taken by the drip probe, and when it is determined that a droplet image including a falling droplet has been obtained, extracts the contour of the falling droplet from the droplet image, estimates the volume of the falling droplet based on the extracted result, calculates the flow rate of the drip tube based on the estimated result, and when it detects one or more defects in the contour, interpolates the one or more defects and then estimates the volume. A measuring device comprising: [Effects of the Invention]

[0021] The present disclosure provides improved accuracy in detecting droplets in a drip tube or in estimating the volume of detected droplets. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a diagram illustrating the configuration of an infusion device and a measurement device according to an embodiment of the present disclosure. [Figure 2] 1 is a diagram illustrating the configuration of an infusion probe of a measurement device according to an embodiment of the present disclosure. FIG. [Figure 3] 1 is an example of an image captured by an infusion probe of a measurement device according to an embodiment of the present disclosure. [Figure 4] 10 is an example of a trend graph of changes in brightness of a first region and a second region of an image captured by an infusion probe of a measurement device according to an embodiment of the present disclosure. [Figure 5]10 is a flowchart illustrating the operation of a controller of the measurement device according to the embodiment of the present disclosure. [Figure 6] FIG. 10 illustrates an algorithm for extracting the contour of a falling drop by a controller of a measurement device according to an embodiment of the present disclosure. [Figure 7] FIG. 10 illustrates an algorithm for interpolating missing contours of a falling drop by a controller of a measurement device according to an embodiment of the present disclosure. [Figure 8] FIG. 10 illustrates a calculation method for estimating the volume of a falling droplet by a controller of a measurement device according to an embodiment of the present disclosure. [Figure 9] 10 is a graph showing basic characteristics of flow rate accuracy in an embodiment of the present disclosure and a comparative example. DETAILED DESCRIPTION OF THE INVENTION

[0023] Hereinafter, an embodiment of the present disclosure will be described with reference to the drawings.

[0024] In each drawing, the same or corresponding parts are denoted by the same reference numerals. In the description of this embodiment, the description of the same or corresponding parts will be omitted or simplified as appropriate.

[0025] The configuration of an infusion device 10 according to this embodiment will be described with reference to FIG.

[0026] The infusion device 10 is a medical device used to administer a liquid such as a nutrient or a medicinal solution to a living body such as a patient. The infusion device 10 forms an infusion line for transporting the liquid to the living body.

[0027] The infusion device 10 includes an infusion tube 20, an infusion container 11, a connector 12, a plurality of infusion tubes 13, a clamp 14, and an infusion pump 15.

[0028] The infusion container 11 contains a liquid. The infusion container 11 is, for example, an infusion bag. The flow rate of the liquid supplied from the infusion container 11 can be visually confirmed through the drip tube 20. The connector 12 can be connected to an indwelling needle placed in a living body. The infusion line is formed by the infusion container 11, the drip tube 20, the connector 12, and an infusion tube 13 that connects these components. A clamp 14 and an infusion pump 15 are attached to the infusion tube 13 that connects the drip tube 20 and the connector 12 in order to adjust the flow rate of the liquid flowing through the infusion line.

[0029] The drip tube 20 is available in two versions: one with a flow rate of 20 drops / mL (i.e., 50 μL / drop) for adults and one with a flow rate of 60 drops / mL (i.e., 16.7 μL / drop) for children. The drip tube 20 drips liquid transported from the upstream side of the infusion line and stores it in an internal drip chamber. The drip tube 20 then discharges the liquid stored in the drip chamber downstream of the infusion line. At least the portion of the peripheral wall of the drip tube 20 that is located above the liquid level in the drip chamber is made of a light-transmitting material.

[0030] The configuration of a measurement device 30 according to this embodiment will be described with reference to FIG.

[0031] The measurement device 30 includes an infusion probe 31 and a controller 32 .

[0032] The drip probe 31 can be attached to the drip tube 20. The drip probe 31 is attached around the drip tube 20 and is used to detect droplets falling inside the drip tube 20. Specifically, the drip probe 31 is attached so that it sandwiches the peripheral wall of the drip tube 20 and is positioned above the liquid level of the stored liquid, and is used to detect droplets falling inside the drip chamber of the drip tube 20.

[0033] The controller 32 may be integrated with the infusion probe 31, but in this embodiment, it is built into the infusion pump 15. The controller 32 is, for example, a computer such as a microcomputer, and includes a processor such as a CPU or GPU and memory such as RAM, ROM, or flash memory. "CPU" is an abbreviation for central processing unit. "GPU" is an abbreviation for graphics processing unit. "RAM" is an abbreviation for random access memory. "ROM" is an abbreviation for read-only memory. The functions of the controller 32 are realized by executing a program on a processor. That is, the functions of the controller 32 are realized by software. Alternatively, the controller 32 may include a programmable circuit such as an FPGA or a dedicated circuit such as an ASIC instead of or in addition to a processor. "FPGA" is an abbreviation for field-programmable gate array. "ASIC" is an abbreviation for application-specific integrated circuit. Some or all of the functions of the controller 32 may be realized by a programmable circuit or a dedicated circuit. That is, some or all of the functions of the controller 32 may be realized by hardware. The controller 32 may further include a communication module for wired or wireless communication with the infusion probe 31. Alternatively, the controller 32 may share the communication module of the infusion pump 15 for communication with the infusion probe 31.

[0034] The configuration of the infusion probe 31 according to this embodiment will be described with reference to FIG.

[0035] The infusion probe 31 has a light source 33 and an image sensor 34 facing each other. The light source 33 is, for example, a near-infrared LED. "LED" is an abbreviation for light-emitting diode. The image sensor 34 is, for example, a camera with a lens. When the infusion probe 31 is attached to the infusion tube 20, it irradiates the infusion tube 20 with light from the light source 33 and captures an image of the infusion tube 20 with the image sensor 34.

[0036] In this embodiment, the drip probe 31 further includes a lens 35. The lens 35 is, for example, an aspherical lens. When the drip probe 31 is attached to the drip tube 20, it irradiates the drip tube 20 with light from the light source 33 as parallel light via the lens 35. By adopting a parallel light optical system, if the liquid is opaque, the light rays are blocked by the liquid. If the liquid is transparent, the direction of the light rays changes due to refraction within the liquid except for the center, resulting in a shadow image in either case. A configuration using a parallel light optical system has the advantage that the falling droplets can be seen even if there are droplets adhering to the wall of the drip tube 20 facing the camera. Another advantage is that the size of the droplets captured does not change even if the droplet drop position changes forward, backward, left, or right. In other words, the size of the droplet shadow does not change even if the droplet drop position becomes farther or closer, or shifts to the left or right.

[0037] The lens 35 may be a Fresnel lens. In this case, the infusion probe 31 can be made smaller.

[0038] An outline of the operation of the controller 32 according to this embodiment will be described with reference to FIGS.

[0039] The controller 32 sequentially acquires images captured by the drip probe 31. The controller 32 stores each acquired image in memory as a captured image 40. When a specific region of the captured image 40 is designated as a first region 41 and another specific region located below the first region 41 is designated as a second region 42, the controller 32 determines that a droplet image 51 containing a falling droplet 60 has been obtained by detecting a first brightness change in the first region 41 and a second brightness change in the second region 42 corresponding to the first brightness change in the first region 41 in time sequence. The controller 32 estimates the volume of the falling droplet 60 using the droplet image 51. The controller 32 calculates the flow rate of the drip tube 20 based on the obtained estimation result. The controller 32 performs flow rate control based on the obtained calculation result. If the controller 32 is integrated with the drip probe 31 instead of being built into the infusion pump 15, the controller 32 may communicate with the infusion pump 15 via wired or wireless communication, thereby notifying the infusion pump 15 of the calculation results and causing the infusion pump 15 to perform flow rate control.

[0040] According to this embodiment, droplets that cause brightness changes in the two regions in the up-down order are detected as falling droplets 60, so when a droplet falls into the liquid stored in the drip chamber, the splashed liquid is less likely to be erroneously detected as falling droplets 60. This improves the accuracy of droplet detection in the drip tube 20. As a result, the volume of the detected droplets is estimated, and the flow rate of the drip tube 20 is calculated based on the estimated result with improved accuracy.

[0041] 3 and 4, the algorithm for detecting falling droplets 60 by controller 32 will now be described.

[0042] In this embodiment, the controller 32 detects peaks in the waveform of the difference between the luminance of the first region 41 and the second region 42 and the moving average of the luminance of the first region 41 and the second region 42 over a certain period of time prior to the capture of the corresponding image as the first luminance change and the second luminance change, respectively. For example, in the captured image 40 shown in FIG. 3, the sum of the pixel luminance along a horizontal line within each region is defined as the "region luminance." As shown in the example shown in FIG. 4, when a trend graph is created by subtracting the current "region luminance" from the moving average of the "region luminance" over a certain period of time, a falling droplet 60 is detected when peaks appear in the first region 41 and the second region 42 in that order. That is, the controller 32 determines that a droplet image 51 has been obtained when it detects a first peak 43 corresponding to the first luminance change and a second peak 44 corresponding to the second luminance change in sequence within a certain period of time. The droplet image 51 is an image taken at the time of detection of the falling droplet 60. In this embodiment, the controller 32 uses the image from which the first luminance change was detected as the droplet image 51, but may also use the image from which the second luminance change was detected as the droplet image 51. In the example shown in FIG. 4, the controller 32 captures the droplet image 51 at the rising point of the first peak 43, and then captures the reference image 52 a predetermined time later. The reference image 52 is an image taken after the passing of the falling droplet 60.

[0043] The controller 32 may determine that the first peak 43 and the second peak 44 are not separable, i.e., occur almost simultaneously, and therefore do not constitute detection of a falling droplet 60. When the controller 32 determines that the first peak 43 and the second peak 44 are not separable, due to the possibility of blockage or empty liquid, the controller 32 may issue a warning to notify a user, such as a medical professional, of an abnormality. Alternatively, the controller 32 may issue a warning to notify a user, such as a medical professional, of an abnormality when a high detection region in which no peaks can be detected continues. Any method of notification may be used, such as displaying a warning message on a screen or outputting a sound, lighting or flashing a warning lamp, or outputting a warning sound.

[0044] The operation of the controller 32 according to this embodiment will be described in detail with reference to Fig. 5. The measurement method according to this embodiment includes at least steps S1 to S6 shown in Fig. 5. The flow shown in Fig. 5 starts when the controller 32 starts acquiring images taken by the infusion probe 31, and ends when the controller 32 finishes acquiring images taken by the infusion probe 31.

[0045] In S1, the controller 32 determines whether or not a droplet image 51 has been obtained using the algorithm described with reference to Figures 3 and 4. If it is determined that a droplet image 51 has been obtained, i.e., if a falling droplet 60 has been detected, step S2 is executed. On the other hand, if it is determined that a droplet image 51 has not been obtained, i.e., if a falling droplet 60 has not been detected, step S1 is executed again.

[0046] In S2, the controller 32 extracts the contour 61 of the falling droplet 60 from the droplet image 51 obtained in S1 using the algorithm shown in FIG. 6. Specifically, the controller 32 subtracts the droplet image 51 from the reference image 52 obtained a predetermined time after the droplet image 51 was obtained to generate a difference image 53. The controller 32 binarizes the generated difference image 53 to generate a binarized image 54. The controller 32 tracks the contour 61 of the falling droplet 60 in the generated binarized image 54 to generate a first extracted image 55. The controller 32 searches the reference image 52 for each point of the contour 61 in the generated first extracted image 55, and deletes any contour points with shadows around them, assuming them to be the contour of an attached droplet. The controller 32 then extracts the remaining portion of the contour 61 to generate a second extracted image 56.

[0047] In S3, the controller 32 determines whether or not one or more points of the contour 61 have been deleted in S2. If it is determined that one or more points of the contour 61 have been deleted, i.e., if one or more defects of the contour 61 have been detected, step S4 is executed. On the other hand, if it is determined that no points of the contour 61 have been deleted, i.e., if no defects of the contour 61 have been detected, step S5 is executed.

[0048] In S4, the controller 32 interpolates the one or more defects detected in S3 using an algorithm such as that shown in FIG. 7. Specifically, in S41, the controller 32 slices the contour 61 at equal intervals along the horizontal direction and vertically with reference to the second extracted image 56. In S42, the controller 32 finds a centerline using slices with both ends. In S43, the controller 32 symmetrically interpolates the one-sided defective slice about the centerline. That is, when the controller 32 detects one-sided defects on either the left or right side as one or more defects, the controller 32 symmetrically interpolates the one-sided defects on either the left or right side. In S44, the controller 32 interpolates the bilaterally defective slice with a straight line or an approximate curve. That is, when the controller 32 detects one-sided defects on both the left and right sides that are in the same vertical position as one or more defects, the controller 32 linearly interpolates the left and right defects on both sides.

[0049] In S5, the controller 32 estimates the volume of the falling droplet 60 based on the extraction result obtained in S2 or the extraction result obtained in S4 after interpolating defects, using a calculation method such as that shown in Fig. 8. Specifically, the controller 32 calculates an approximate value of the volume of the falling droplet 60 by slicing the contour 61 at equal intervals in the vertical direction along the horizontal direction with reference to the second extracted image 56 generated in S2, or by integrating a cylinder corresponding to each slice using the image sliced in S4.

[0050] In S6, the controller 32 calculates the flow rate of the drip tube 20 based on the estimation result obtained in S5. A known method can be used to calculate the flow rate from the droplet volume.

[0051] According to this embodiment, the missing portion of the detected droplet's contour is interpolated, improving the accuracy of the volume estimation of the detected droplet. As a result, the accuracy of the flow rate when calculating the flow rate of the drip tube 20 based on the obtained estimation result is improved.

[0052] For example, as shown in FIG. 9, in "drop integration," which integrates a droplet volume of 50 μl, the flow rate accuracy varies greatly between when the liquid is water and when it contains 50% glucose, whereas in "cylinder integration," which integrates the droplet volume as a horizontally sliced cylinder using the above-described operation, the flow rate accuracy is almost the same between when the liquid is water and when it contains 50% glucose. In other words, compared to "drop integration," in the "cylinder integration" of this embodiment, the flow rate accuracy is less affected by the type of liquid. Moreover, compared to "drop integration," in the "cylinder integration" of this embodiment, the flow rate accuracy is also less affected by the flow velocity.

[0053] According to this embodiment, it is also possible to automate the settings of the infusion pump 15 or detect free flow. For example, it is possible to detect a sudden liquid leak when the drip tube 20 is accidentally removed and notify a user such as a medical professional. Any method of notification can be used, such as displaying a warning message on a screen or outputting a sound, lighting or flashing a warning lamp, or outputting a warning sound.

[0054] As described above, the controller 32 may issue a warning when it determines that the first peak 43 and the second peak 44 are inseparable. This warning may be set as a preliminary free flow warning. When free flow occurs, the falling droplet 60 may become a liquid column within the drip probe 31. The outline of the liquid column is considered to extend longer in the direction of gravity than the outline of the falling droplet 60 under normal conditions when free flow is not occurring. The outline of the liquid column is considered to be elongated rectangular, whereas the outline of the falling droplet 60 under normal conditions when free flow is not occurring is circular. That is, when free flow occurs, the controller 32 is considered to extract an elongated rectangular outline as the outline 61 of the falling droplet 60 in S2. Therefore, the controller 32 may issue a warning when it determines that the vertical length of the extracted outline satisfies a warning condition, such as 70% or more, preferably 80% or more, of the vertical length of the captured image 40. This warning may be set as a main free flow warning. Alternatively, the controller 32 may issue a warning when it determines through image shape comparison that the shape of the extracted contour satisfies a warning condition, such as that the shape is rectangular. This warning may be set as a main free flow warning. The preliminary free flow warning may be set to be distinguishable as a warning of a shorter duration than the main free flow warning. When free flow occurs, there is a risk of unintentionally administering a large amount of medicinal liquid. However, according to the above example, the two-stage determination of free flow makes it possible to issue a warning to users such as medical personnel with high accuracy, thereby improving safety.

[0055] The drip probe 31 may further include an angle sensor. In such a modification, the controller 32 detects the tilt of the drip probe 31 relative to the direction of gravity using the angle sensor, rotates each acquired image according to the detected tilt, and then determines whether or not a droplet image 51 has been obtained. In other words, if the drip tube 20 and the drip probe 31 are tilted obliquely relative to the vertical direction, the controller 32 rotates the captured image 40 so that the center line of the captured image 40 faces vertically, and then performs the droplet volume calculation process.

[0056] The controller 32 may determine whether the loss rate of the contour 61 exceeds a threshold. In such a variation, if the controller 32 determines that the loss rate of the contour 61 exceeds a threshold, instead of estimating the volume of the falling droplet 60, it applies an estimation result obtained using one or more other droplet images obtained before the acquisition of the droplet image 51. The threshold is, for example, 50%, but can be changed as appropriate. Since there are no attached droplets at the start of the drip, the loss rate is considered low. However, as time passes, the number of attached droplets gradually increases, and the loss rate is expected to increase. However, if the droplet volume is estimated for a certain period of time, the volume thereafter will not change, or even if it does change, it will only change slightly. Therefore, once the loss rate exceeds the threshold, a certain level of accuracy can be maintained by using the average of the droplet volume estimates obtained previously. In another variation, if the controller 32 determines that the loss rate of the contour 61 exceeds a threshold, it causes the drip probe 31 to vibrate the drip tube 20 to remove droplets attached to the inner surface of the drip probe 31. For example, drip probe 31 may have a vibration actuator for vibrating drip tube 20. In yet another variation, when controller 32 determines that the defect rate of contour 61 exceeds a threshold, it causes drip probe 31 to emit ultrasonic waves into drip tube 20 to remove droplets adhering to the inner circumferential surface of drip probe 31. For example, drip probe 31 may have an ultrasonic source for emitting ultrasonic waves.

[0057] The present disclosure is not limited to the above-described embodiments. For example, two or more blocks shown in the block diagrams may be integrated, or one block may be divided. Two or more steps shown in the flowcharts may be executed in parallel or in a different order, instead of being executed in chronological order as described, depending on the processing capabilities of the device executing each step, or as needed. Other modifications are possible within the scope of the present disclosure. [Explanation of symbols]

[0058] 10 Infusion device 11 Infusion container 12 Connectors 13 Infusion tube 14 Clamp 15 Infusion pump 20 Drip tube 30 Measuring Equipment 31 Infusion probe 32 Controller 33 Light source 34 Image Sensor 35 Lens 40 captured images 41 First area 42 Second area 43 First Peak 44 Second Peak 51 droplet images 52 Reference Images 53 Difference Image 54 Binarized Images 55 First extracted image 56 Second extracted image 60 falling droplets 61 Contour

Claims

1. An infusion probe having a light source and an image sensor facing each other, which, when attached to an infusion tube, irradiates the infusion tube with light from the light source and captures an image of the infusion tube with the image sensor; a controller that sequentially acquires images taken by the drip probe, defines a specific region of each acquired image as a first region, and defines another specific region located below the first region as a second region, and determines that a droplet image including a falling droplet has been obtained by detecting a first luminance change in the first region and a second luminance change in the second region corresponding to the first luminance change in the second region in time sequence, estimates the volume of the falling droplet using the droplet image, and calculates the flow rate of the drip tube based on the estimated result; A measuring device comprising:

2. The measuring device of claim 1, wherein the controller detects, as the first luminance change and the second luminance change, peaks that appear in waveforms of differences between the luminance of the first region and the second region and the moving averages of the luminance of the first region and the second region within a certain period going back from the time of acquisition of the corresponding images.

3. The measurement device according to claim 2 , wherein the controller issues a warning when it determines that the peak corresponding to the first luminance change and the peak corresponding to the second luminance change are inseparable.

4. The measuring device according to claim 1 , wherein the controller uses an image from which the first luminance change is detected as the droplet image.

5. The infusion probe further comprises an angle sensor; The measuring device described in claim 1, wherein when the controller detects the inclination of the infusion probe relative to the direction of gravity using the angle sensor, it rotates each acquired image according to the detected inclination and then determines whether the droplet image has been obtained.

6. 2. The measurement device according to claim 1, wherein the controller extracts a contour of the falling droplet from the droplet image, estimates the volume based on the extracted result, and, if one or more defects in the contour are detected, interpolates the one or more defects before estimating the volume.

7. The measurement device according to claim 6 , wherein when the controller detects a unilateral defect as the one or more defects, the controller symmetrically interpolates the unilateral defect.

8. The measuring device according to claim 6 , wherein when the one or more defects are detected as defects on both the left and right sides that are in the same vertical position, the controller performs linear interpolation between the defects on both the left and right sides.

9. The measuring device according to claim 6 , wherein the controller issues a warning when it determines that the vertical length of the contour satisfies a warning condition.

10. The measuring device according to claim 6 , wherein the controller issues a warning when it determines that the shape of the contour satisfies a warning condition.

11. The measurement device of claim 6, wherein when the controller determines that the missing rate of the contour exceeds a threshold, instead of estimating the volume, the controller applies an estimation result obtained using one or more other droplet images obtained before the droplet image was acquired.

12. The measuring device according to claim 6, wherein when the controller determines that the contour loss rate exceeds a threshold, the controller vibrates the drip tube to remove droplets adhering to the inner surface of the drip probe.

13. The measuring device described in claim 6, wherein when the controller determines that the contour defect rate exceeds a threshold value, the controller causes the drip probe to emit ultrasonic waves into the drip tube to remove droplets adhering to the inner surface of the drip probe.

14. An infusion probe having a light source and an image sensor facing each other, which, when attached to an infusion tube, irradiates the infusion tube with light from the light source and captures an image of the infusion tube with the image sensor; A controller that sequentially acquires images taken by the drip probe, and when it is determined that a droplet image including a falling droplet has been obtained, extracts the contour of the falling droplet from the droplet image, estimates the volume of the falling droplet based on the extracted result, calculates the flow rate of the drip tube based on the estimated result, and when it detects one or more defects in the contour, interpolates the one or more defects and then estimates the volume. A measuring device comprising:

Images