Measurement device, program, and measurement method

Abstract

This measurement device comprises: an infusion probe that, when attached to an infusion tube, sequentially detects falling droplets inside the infusion tube by means of a sensor, irradiates the infusion tube with light from a light source, and uses a camera to capture an image of the infusion tube; and a controller that controls the infusion probe. When a first falling droplet is detected by the infusion probe during operation of the camera, the controller estimates the volume of the first falling droplet using the image captured by the infusion probe, stops operation of the camera, uses the result of estimating the volume of one or more falling droplets including the first falling droplet as a basis to calculate a predicted falling time at which a second falling droplet will occur after the first falling droplet, and resumes operation of the camera by the calculated predicted falling time.

Description

Measuring device, program, and measuring method

[0001] This disclosure relates to measuring devices, programs, and measuring methods.

[0002] Patent Document 1 discloses a drip volume measuring device comprising an imaging unit and a data processing unit. The imaging unit images a growing droplet growing at the lower end of a nozzle at multiple points in time. The data processing unit calculates the flow rate of droplets intermittently falling from the lower end of the nozzle by analyzing multiple image data acquired by the imaging unit. The drip volume measuring device also includes a counting unit. The counting unit detects when a droplet leaves the lower end of the nozzle and counts the number of droplets. The data processing unit calculates the estimated volume of the droplets falling after leaving the lower end of the nozzle by analyzing multiple image data, and calculates the flow rate from the number of droplets and the estimated volume.

[0003] Patent Document 2 discloses a flow rate control system comprising an imaging device, a volume calculation unit, a drip detection means, a drip period calculation unit, a target period calculation unit, and a drip period adjustment unit. The imaging device images the droplets dripping from the nozzle. The volume calculation unit calculates the volume of the droplets falling from the nozzle based on the image data output from the imaging device. The drip detection means detects the timing at which the droplets begin to fall away from the nozzle or the number of times the droplets have fallen away from the nozzle. The drip period calculation unit calculates the drip period of the droplets dripping from the nozzle based on this timing or number of times. The target period calculation unit calculates the target drip period based on a preset target flow rate and the volume of the droplets calculated by the volume calculation unit. The drip period adjustment unit controls a flow rate adjustment unit that changes the flow rate of the droplets dripping from the nozzle so that the drip period calculated by the drip period calculation unit approaches the target drip period.

[0004] International Publication No. 2016 / 114264, Japanese Patent Publication No. 2023-154362

[0005] The drip volume measuring device disclosed in Patent Document 1 calculates the estimated volume of at least one falling droplet, then stops the operation of the imaging unit and does not continue to image droplets falling thereafter. Therefore, the accuracy of flow rate control is low.

[0006] The flow rate control system disclosed in Patent Document 2 calculates the dripping period, but it is not configured to operate the imaging device at the precise moment when the next droplet begins to fall; instead, it keeps the imaging device running continuously. As a result, it consumes a lot of power.

[0007] The purpose of this disclosure is to provide a measuring device, program, and measuring method that can efficiently and continuously image droplets in a drip chamber.

[0008] Some aspects of this disclosure are shown below.

[0009] [1] A measuring device comprising: a sensor, a light source and a camera facing each other, an infusion probe that, when attached to an infusion chamber, sequentially detects falling droplets inside the infusion chamber with the sensor, irradiates the infusion chamber with light from the light source, and captures an image of the infusion chamber with the camera; and a controller that controls the infusion probe, wherein when the infusion probe detects a first falling droplet while the camera is operating, the controller estimates the volume of the first falling droplet using the image captured by the infusion probe and stops the operation of the camera, calculates the predicted falling time at which the second falling droplet will occur after the first falling droplet based on the estimated volume of one or more falling droplets including the first falling droplet, and restarts the operation of the camera by the calculated predicted falling time.

[0010] [2] The measuring device according to [1], wherein the controller uses a moving average of the volumes estimated for the falling droplets detected by the drip probe prior to the first falling droplet, as a result of estimating the volume of one or more falling droplets.

[0011] [3] The measuring device according to [2], wherein the controller updates the total flow rate of the drip chamber based on the result of estimating the volume of one or more falling droplets.

[0012] [4] The measuring device according to [3], wherein the controller adds the volume of the second falling droplet, calculated using the image captured by the drip probe, to the total flow rate when the second falling droplet is detected by the drip probe while the camera is in operation, and adds the moving average to the total flow rate when the second falling droplet is detected by the drip probe while the camera is not in operation.

[0013] [5] The measuring device according to [3] or [4], wherein the controller adjusts the amount of fluid delivered by the infusion pump based on the result of comparing the calculated total flow rate with the expected flow rate determined according to the set flow rate of the infusion pump.

[0014] [6] The controller is a measuring device according to any one of items [3] to [5] that displays the calculated total flow rate on a monitor.

[0015] [7] The measuring device according to any one of [1] to [6], wherein the controller restarts the operation of the camera at a time obtained by subtracting a time determined according to the set flow rate of the drip chamber from the predicted drop time.

[0016] [8] A program that causes a computer to communicate with an infusion probe, which comprises a sensor, a light source and a camera facing each other, and which, when attached to a drip chamber, sequentially detects falling droplets inside the drip chamber with the sensor, irradiates the drip chamber with light from the light source, and takes an image of the drip chamber with the camera, to perform the following actions when the infusion probe detects a first falling droplet while the camera is operating: estimate the volume of the first falling droplet using the image taken by the infusion probe and stop the operation of the camera; calculate a predicted falling time when the second falling droplet will occur, following the first falling droplet, based on the result of estimating the volume of one or more falling droplets including the first falling droplet; and restart the operation of the camera by the calculated predicted falling time.

[0017] [9] A measurement method comprising: when an intravenous probe, which includes a sensor and a light source and camera facing each other, is attached to a drip chamber, the sensor sequentially detects falling droplets inside the drip chamber, irradiates the drip chamber with light from the light source, and captures an image of the drip chamber with the camera; when a controller detects a first falling droplet by the intravenous probe while the camera is operating, it estimates the volume of the first falling droplet using the image captured by the intravenous probe and stops the operation of the camera; the controller calculates a predicted falling time at which a second falling droplet will occur, based on the result of estimating the volume of one or more falling droplets including the first falling droplet; and the controller restarts the operation of the camera by the calculated predicted falling time.

[0018] According to this disclosure, it is possible to continuously image droplets in the drip chamber efficiently.

[0019] This figure shows the configuration of the infusion system and measuring device according to the embodiment of this disclosure. This is a horizontal cross-sectional view showing the configuration of the infusion probe according to the embodiment of this disclosure. This is a vertical cross-sectional view showing the configuration of the infusion probe according to the embodiment of this disclosure. This figure shows the operating period of the camera and sensor of the infusion probe according to the embodiment of this disclosure. This is an example of an image taken by the infusion probe according to the embodiment of this disclosure. This is a flowchart showing the operation of the controller according to the embodiment of this disclosure. This is a flowchart showing a modified example of the operation of the controller according to the embodiment of this disclosure.

[0020] Hereinafter, one embodiment of this disclosure will be described with reference to the figures.

[0021] In each figure, identical or corresponding parts are denoted by the same reference numerals. In the description of this embodiment, the description of identical or corresponding parts will be omitted or simplified as appropriate.

[0022] Referring to Figure 1, the configuration of the infusion system 10 according to this embodiment will be described.

[0023] The infusion system 10 is a medical device used to administer liquids such as nutritional supplements or medicinal solutions to a living body, such as a patient. The infusion system 10 forms an infusion line for transporting the liquid to the living body.

[0024] The infusion system 10 includes a drip chamber 20, an infusion container 11, a connector 12, multiple infusion tubes 13, a clamp 14, and an infusion pump 15.

[0025] The infusion container 11 contains a liquid. The infusion container 11 is, for example, an infusion bag that contains a drug such as physiological saline. The connector 12 can be connected to an indwelling needle placed in the body. Multiple infusion tubes 13 connect the components of the infusion line, namely the infusion container 11, the drip chamber 20, and the connector 12. The clamp 14 and infusion pump 15 are attached to the infusion tubes 13 connecting the drip chamber 20 and the connector 12 in order to adjust the flow rate of the liquid flowing through the infusion line.

[0026] The drip chamber 20 dispenses the liquid transported from the upstream of the infusion line and stores it in its internal drip chamber. The drip chamber 20 then discharges the liquid stored in the drip chamber downstream of the infusion line. The flow rate of the liquid supplied from the infusion container 11 is visible through the drip chamber 20. The drip chamber 20 comes in, for example, an adult version with a flow rate of 20 drops / mL, i.e., 50 μL / drop, and a pediatric version with a flow rate of 60 drops / mL, i.e., 16.7 μL / drop. At least the portion of the peripheral wall of the drip chamber 20 located above the liquid level of the stored liquid in the drip chamber is made of a light-transmitting material.

[0027] Referring to Figure 1, the configuration of the measuring device 30 according to this embodiment will be described.

[0028] The measuring device 30 comprises an intravenous drip probe 31 and a controller 32.

[0029] The drip probe 31 can be attached to the drip chamber 20. The drip probe 31 is used to detect droplets falling inside the drip chamber 20 when it is attached around the drip chamber 20. Specifically, the drip probe 31 is used to detect droplets falling inside the drip chamber 20 when it is attached so as to clamp the peripheral wall of the drip chamber 20 and is positioned above the liquid level of the stored liquid. The detailed configuration of the drip probe 31 will be described later.

[0030] In this embodiment, the controller 32 is built into the infusion pump 15 as shown in Figure 1, but it may also be integrated with the drip probe 31. The controller 32 is, for example, a computer such as a microcomputer, and has 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 the processor executing a program loaded into memory. In other words, the functions of the controller 32 are realized by software. Alternatively, the controller 32 may have a programmable circuit such as an FPGA or a dedicated circuit such as an ASIC instead of or in addition to the 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 implemented by programmable circuits or dedicated circuits. That is, some or all of the functions of the controller 32 may be implemented by hardware circuits. The controller 32 may further have a communication module for communicating with the infusion probe 31 by wire or wireless. Alternatively, the controller 32 may share the communication module of the infusion pump 15 for communicating with the infusion probe 31.

[0031] Next, referring to FIGS. 2 and 3, the configuration of the drip probe 31 according to the present embodiment will be described. FIGS. 2 and 3 are a horizontal cross-sectional view and a vertical cross-sectional view showing the configuration of the drip probe 31 according to the present embodiment, respectively.

[0032] The drip probe 31 includes a sensor 44, a light source 41 and a camera 46 that face each other.

[0033] The sensor 44 is an optical sensor that detects light from the light source 41. The sensor 44 detects that a falling droplet has occurred in the drip cylinder 20 in response to the light from the light source 41 being blocked. The sensor 44 is, for example, a two-stage phototransistor or a photodiode.

[0034] The light source 41 irradiates light toward the sensor 44 and the camera 46 through the drip cylinder 20. The light source 41 is, for example, a near-infrared LED. "LED" is an abbreviation for light-emitting diode.

[0035] The camera 46 captures the inside of the drip cylinder 20 with the light from the light source 41. The camera 46 is, for example, a near-infrared camera. The camera 46 includes an image sensor and a condensing element that collects light on the image sensor. As the image sensor of the camera 46, for example, a CMOS or a CCD is used. "CMOS" is an abbreviation for complementary metal-oxide-semiconductor. "CCD" is an abbreviation for charge-coupled device. As the condensing element of the camera 46, for example, a lens or a pinhole is used.

[0036] When the drip probe 31 is attached to the drip chamber 20, it sequentially detects the falling droplets inside the drip chamber 20 with the sensor 44, irradiates the drip chamber 20 with the light from the light source 41, and takes an image of the drip chamber 20 with the camera 46. In the present embodiment, the sensor 44 has two upper and lower stages so as not to erroneously detect the splashed liquid as a falling droplet when a droplet falls into the stored liquid in the dropping chamber. That is, only the droplets detected in the order from top to bottom are determined to be falling droplets, and the droplets detected in the reverse order from top to bottom are determined not to be falling droplets. In the present embodiment, the camera 46 is disposed above the sensor 44. Therefore, even if the camera 46 is activated when the sensor 44 detects a falling droplet, it is impossible to image the falling droplet. That is, in order to image the falling droplet, the camera 46 needs to be already activated when the sensor 44 detects the falling droplet.

[0037] In the present embodiment, the drip probe 31 further includes an optical element 42, a first condenser 43, and a second condenser 45. The optical element 42, the first condenser 43, and the second condenser 45 are, for example, aspherical lenses or Fresnel lenses.

[0038] When the drip probe 31 is attached to the drip chamber 20, it irradiates the drip chamber 20 with the light from the light source 41 as parallel light through the optical element 42. The first condenser 43 and the second condenser 45 condense the parallel light that has passed through the drip chamber 20. In the present embodiment, the first condenser 43 is a cylindrical lens that has the same curved surface as the second condenser 45, condenses light in the horizontal direction, but does not condense light in the vertical direction. The sensor 44 detects the interruption of the light emitted from the first condenser 43 as the fall of a droplet. In the present embodiment, the second condenser 45 is a condenser lens that condenses light in both the horizontal and vertical directions. The camera 46 converts the light emitted from the second condenser 45 into an image.

[0039] By adopting a parallel light optical system, if the liquid is opaque, the light rays will be blocked by the liquid, and if the liquid is transparent, the traveling direction of the light rays will change due to refraction in the liquid except at the center. In either case, an image of a shadow can be obtained.

[0040] Furthermore, a configuration employing a parallel optical system has the characteristic that the size of the imaged droplet does not change even if the droplet's falling position changes forward, backward, left, or right. In other words, the size of the droplet's shadow does not change whether the droplet's falling position is farther away, closer, shifted to the left, or shifted to the right. This prevents droplets adhering to the wall of the drip chamber 20 on the camera 46 side from being captured at a large size. As a result, the camera 46 can reduce the influence of droplets adhering to the wall and capture droplets falling near the center of the drip chamber 20.

[0041] In this embodiment, the drip probe 31 further comprises a first optical transducer 51 and a second optical transducer 52. The first optical transducer 51 and the second optical transducer 52 are aspherical lenses designed by performing optical simulations using parameters such as the refractive index of the drip chamber wall material and the curvature of the drip chamber wall.

[0042] In a configuration employing a parallel light optical system, the parallelism of the incident light may be lost towards the periphery due to the refraction of light from the drip chamber wall, and the subject may appear smaller the further it is from the camera 46. Therefore, the first optical converter 51 converts the optical paths of multiple light components contained in the parallel light emitted from the optical element 42, so that multiple light components travel non-parallel to each other before entering the drip chamber 20, are refracted at least partially when entering the drip chamber 20, and travel parallel to each other inside the drip chamber 20 after entering the drip chamber 20. The second optical converter 52 converts the optical paths of multiple light components that travel parallel to each other inside the drip chamber 20, are emitted from the drip chamber 20, and are refracted at least partially when emitted from the drip chamber 20, so that it emits parallel light.

[0043] This allows the infusion probe 31 to accurately image the peripheral area of ​​the wall surface of the drip chamber 20.

[0044] Referring to Figures 4 and 5, an overview of the operation of the controller 32 according to this embodiment will be described.

[0045] When the sensor 44 detects the fall of the first droplet 80 in the drip chamber 20, the controller 32 stops the operation of the camera 46. The controller 32 calculates the volume of the first droplet from the image 70 related to the first droplet 80 captured by the camera 46. Based on the calculated volume of the first droplet, the controller 32 calculates a moving average of the droplet volumes. Based on the calculated moving average of the droplet volumes, the controller 32 predicts the fall time of the second droplet that follows the first droplet 80. The fall time of the next droplet can be predicted from the set flow rate of the infusion pump 15. Based on the predicted fall time, the controller 32 determines when to restart the operation of the camera 46. In the camera operation periods P1 to P4 shown in Figure 4, if the droplet could not be captured at the predicted fall time, as in P4, the controller 32 continues the operation of the camera 46 until the droplet can be captured.

[0046] Referring to Figure 6, the operation of the controller 32 according to this embodiment will be described in detail. The operation described below corresponds to the measurement method according to this embodiment. That is, the measurement method according to this embodiment includes steps S101 to S116 shown in Figure 6.

[0047] In S101, the controller 32 sets the flow rate of the infusion pump 15. Known methods can be used to set the flow rate.

[0048] In S102, the controller 32 starts the operation of the camera 46. This means that the camera 46 is turned on at the start so that the first drop is always captured.

[0049] In S103, the controller 32 detects the first dripping droplet D from the drip probe 31 while the camera 46 is in operation. １ Wait until a drop is detected. The drip probe 31 sequentially detects the drip droplets inside the drip chamber 20 using the sensor 44. Known methods can be used to detect the drip droplets. While the camera 46 is operating, the drip probe 31 continues to capture images of the drip chamber 20 with the camera 46.

[0050] While the camera 46 is in operation, a droplet D falls from the drip probe 31. １If this is detected (YES in S103), in S104, the controller 32 stops the operation of the camera 46.

[0051] In S105, the controller 32 uses the image captured by the drip probe 31 to determine the falling droplet D １ We estimate the volume of the falling droplet. Known methods can be used to estimate the volume of the falling droplet.

[0052] In S106, the controller 32 determines the falling droplet D estimated in S105. １ The volume is stored in memory as the total flow rate of the drip chamber 20.

[0053] In S107, the controller 32 determines the falling droplet D estimated in S105. １ The volume is stored in memory as a moving average of droplet volumes.

[0054] In S108, the controller 32 compares the total flow rate stored in memory with the expected flow rate at the current time. The expected flow rate at the current time is the total flow rate at the current time calculated based on the flow rate of the infusion pump 15 set in S101.

[0055] If the total flow rate stored in memory is less than the expected flow rate at the current time, in S109, the controller 32 increases the fluid delivery rate of the infusion pump 15.

[0056] If the total flow rate stored in memory is greater than the expected flow rate at the current time, in S110, the controller 32 reduces the amount of fluid delivered by the infusion pump 15.

[0057] After S109 or S110, or when the total flow rate stored in memory matches the expected flow rate at the current time, in S111, when i is an integer of 2 or more, the controller 32 determines the next falling droplet D based on the moving average of droplet volumes stored in memory. ｉ Calculate the predicted fall time at which the event will occur.

[0058] In S112, the controller 32 waits until the time α determined according to the set flow rate of the drip chamber 20 reaches the time obtained by subtracting the predicted drop time calculated in S111. It is desirable that the time α be 5% or more and 20% or less of the theoretical value of the drop interval of the falling liquid droplets calculated from the set flow rate of the drip chamber 20.

[0059] When the time obtained by subtracting the time α from the predicted drop time is reached (YES in S112), in S113, the controller 32 resumes the operation of the camera 46. In S114, the controller 32 waits until the i-th falling liquid droplet D is detected by the drip probe 31. ｉ until it is detected.

[0060] When the falling liquid droplet D is detected by the drip probe 31 ｉ (YES in S114), in S115, the controller 32 determines whether the camera 46 is operating.

[0061] When the camera 46 is not operating (NO in S115), the falling liquid droplet D ｉ occurs earlier than predicted, and the camera 46 fails to image the falling liquid droplet D ｉ . Therefore, in S116, the controller 32 adds the most recent droplet volume moving average stored in the memory to the most recent total flow rate stored in the memory instead of the volume of the falling liquid droplet D to update the total flow rate. ｉ to update the total flow rate.

[0062] On the other hand, when the camera 46 is operating (YES in S115), the steps after S104 are executed again. That is, in S104, the controller 32 stops the operation of the camera 46. In S105, the controller 32 estimates the volume of the falling liquid droplet D using the image captured by the drip probe 31. ｉ

[0063] In S106, the controller 32 adds the volume of the falling liquid droplet D estimated in S105 ｉ to the most recent total flow rate stored in the memory to update the total flow rate.

[0064] In S107, the controller 32 uses the falling liquid droplet D estimated in S105 ｉBased on the volume, the most recent droplet volume moving average stored in memory is updated. The moving average width should preferably be between 4 and 32 recent droplets.

[0065] In S108, the controller 32 compares the total flow rate stored in memory with the expected flow rate at the current time.

[0066] For steps S108 and beyond, the first falling droplet D １ The explanation is omitted as it is the same as when [another condition] was detected.

[0067] As described above, in this embodiment, when the first dripping droplet is detected by the drip probe 31 while the camera 46 is operating, the controller 32 estimates the volume of the first dripping droplet using the image captured by the drip probe 31 and stops the operation of the camera 46. Based on the estimated volume of one or more dripping droplets, including the first dripping droplet, the controller 32 updates the total flow rate of the drip chamber 20 and calculates the predicted dripping time for the second dripping droplet, which follows the first. The controller 32 restarts the operation of the camera 46 by the calculated predicted dripping time.

[0068] For example, the first falling droplet D １ If we consider this as the first falling droplet, then the second falling droplet D ２ This corresponds to the second falling droplet. The second falling droplet D ２ If we consider this as the first falling droplet, then the third falling droplet D ３ This corresponds to the second falling droplet.

[0069] According to this embodiment, the camera 46 can be operated to coincide with the timing when the next droplet begins to fall. Therefore, it is possible to prevent the camera 46 from continuing to operate while no droplets are falling, and thus efficiently image the droplets inside the drip chamber 20.

[0070] In this embodiment, the controller 32 estimates the volume of one or more falling droplets, including the first falling droplet, and uses a moving average of the volumes estimated for falling droplets detected by the drip probe 31 before the first falling droplet. Therefore, even if a second falling droplet is detected by the drip probe 31 while the camera 46 is stopped, the controller 32 can maintain the accuracy of calculating the total flow rate by adding the moving average to the total flow rate. Furthermore, if a second falling droplet is detected by the drip probe 31 while the camera 46 is operating, the controller 32 simply adds the volume of the second falling droplet, calculated using the image captured by the drip probe 31, to the total flow rate.

[0071] For example, the first falling droplet D １ If we consider this as the first falling droplet, then falling droplet D １ The estimated volume of the second falling droplet D corresponds to the moving average of the estimated volumes of falling droplets detected before the first falling droplet. ２ If we consider this as the first falling droplet, then falling droplet D １ Estimated volume and falling droplet D ２ The sum of the estimated volume of the first droplet and the second droplet, divided by two, corresponds to the moving average of the estimated volumes of droplets detected before the first droplet.

[0072] In this embodiment, the controller 32 adjusts the fluid delivery rate of the infusion pump 15 based on the result of comparing the calculated total flow rate with the expected flow rate determined according to the set flow rate of the infusion pump 15. However, as one modification, the controller 32 may display the calculated total flow rate on a monitor. Alternatively, the controller 32 may adjust the fluid delivery rate of the infusion pump 15 based on the result of comparing the flow rate set in the infusion pump 15 with the calculated moving average.

[0073] Referring to Figure 7, the operation of the controller 32 in such a modified example will be described in detail. The operation described below corresponds to the measurement method according to one modified example of this embodiment. That is, the measurement method according to one modified example of this embodiment includes the steps S201 to S213 shown in Figure 7.

[0074] Steps S201 to S206 are the same as steps S102 to S107 shown in Figure 6, so their explanation will be omitted.

[0075] In S207, the controller 32 displays the total flow rate stored in memory and the hourly flow rate calculated from the total flow rate on the monitor. The monitor is, for example, provided on the infusion pump 15, but may also be provided on other devices such as the drip probe 31, or as a separate device. This allows the user to adjust the hourly flow rate by operating the clamp 14, etc., based on the hourly flow rate displayed on the monitor. In other words, it is easier to adjust the hourly flow rate accurately than by adjusting it while observing the interval between droplets falling in the drip chamber 20. Furthermore, the display of the total flow rate on the monitor enables the user to accurately manage the administration time.

[0076] After S207, steps S208 and onward are executed. Steps S208 to S213 are the same as steps S111 to S116 shown in Figure 6, so their explanation is omitted.

[0077] This disclosure is not limited to the embodiments described above. For example, two or more blocks shown in the block diagram may be combined, or one block may be divided. Instead of executing two or more steps shown in the flowchart in chronological order as described, they may be executed in parallel or in a different order, depending on the processing capacity of the device performing each step, or as necessary. Other modifications are possible without departing from the spirit of this disclosure.

[0078] 10 Infusion system 11 Infusion container 12 Connector 13 Infusion tube 14 Clamp 15 Infusion pump 20 Drip chamber 30 Measuring device 31 Drip probe 32 Controller 41 Light source 42 Optical element 43 First light-gathering element 44 Sensor 45 Second light-gathering element 46 Camera 51 First optical transducer 52 Second optical transducer 70 Image 80 First droplet

Claims

1. A measuring device comprising: a drip probe comprising a sensor, a light source and a camera facing each other, which, when attached to a drip chamber, sequentially detects falling droplets inside the drip chamber with the sensor, irradiates the drip chamber with light from the light source, and captures an image of the drip chamber with the camera; and a controller that controls the drip probe, wherein when a first falling droplet is detected by the drip probe while the camera is operating, the controller estimates the volume of the first falling droplet using the image captured by the drip probe and stops the operation of the camera, calculates the predicted falling time at which the second falling droplet will occur after the first falling droplet based on the estimated volume of one or more falling droplets including the first falling droplet, and restarts the operation of the camera by the calculated predicted falling time.

2. The measuring device according to claim 1, wherein the controller uses a moving average of the volumes estimated for falling droplets detected by the drip probe prior to the first falling droplet, as a result of estimating the volume of one or more falling droplets.

3. The measuring device according to claim 2, wherein the controller updates the total flow rate of the drip chamber based on the result of estimating the volume of one or more falling droplets.

4. The measuring device according to claim 3, wherein the controller adds the volume of the second falling droplet, calculated using the image captured by the drip probe, to the total flow rate when the second falling droplet is detected by the drip probe while the camera is in operation, and adds the moving average to the total flow rate when the second falling droplet is detected by the drip probe while the camera is not in operation.

5. The measuring device according to claim 3 or 4, wherein the controller adjusts the amount of fluid delivered by the infusion pump based on the result of comparing the calculated total flow rate with an expected flow rate determined according to the set flow rate of the infusion pump.

6. The measuring device according to claim 3 or 4, wherein the controller displays the calculated total flow rate on a monitor.

7. The measuring device according to claim 1, wherein the controller restarts the operation of the camera at a time obtained by subtracting a time determined according to the set flow rate of the drip chamber from the predicted drop time.

8. A program that causes a computer to communicate with an infusion probe, which comprises a sensor, a light source and a camera facing each other, and which, when attached to a drip chamber, sequentially detects falling droplets inside the drip chamber with the sensor, irradiates the drip chamber with light from the light source, and takes an image of the drip chamber with the camera, to execute the following actions when the drip probe detects a first falling droplet while the camera is operating: estimate the volume of the first falling droplet using the image taken by the drip probe and stop the operation of the camera; calculate a predicted falling time when the second falling droplet will occur, following the first falling droplet, based on the estimated volume of one or more falling droplets including the first falling droplet; and restart the operation of the camera by the calculated predicted falling time.

9. A measurement method comprising: when an intravenous probe, which includes a sensor and a light source and camera facing each other, is attached to a drip chamber, the sensor sequentially detects falling droplets inside the drip chamber, irradiates the drip chamber with light from the light source, and captures an image of the drip chamber with the camera; when a controller detects a first falling droplet by the intravenous probe while the camera is operating, it estimates the volume of the first falling droplet using the image captured by the intravenous probe and stops the operation of the camera; the controller calculates a predicted falling time at which a second falling droplet will occur, based on the result of estimating the volume of one or more falling droplets including the first falling droplet; and the controller restarts the operation of the camera by the calculated predicted falling time.

Images