JP2017086907A - Droplet volume estimation device and infusion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a droplet volume estimation device that achieves accuracy in the estimation of a droplet volume as much as possible while simplifying and miniaturizing a structure and processing in estimating the droplet volume for giving an infusion to a patient with an accurate amount without complicating the structure and processing, and provide an infusion device having that function for giving an infusion to a patient with an accurate amount as close to a measured value as possible.SOLUTION: Dripping in a drip tube is recognized by a dripping sensor in step 10, dripping intervals are measured in step 131, and if there is a trend in the dripping intervals, a timing of image acquisition by an imaging sensor is determined and an image of a droplet is acquired in steps 133 and 134. A droplet volume is calculated in step 135, and the dripping intervals according to the volume calculation are determined in step 136. If the dripping intervals are not the same as the present dripping intervals as a result, the flow rate is adjusted by a flow rate adjustment unit (tube clamp) in step 137.SELECTED DRAWING: Figure 9

Description

  The present invention relates to a droplet volume estimation device and an infusion device, and more particularly to a droplet volume estimation device that estimates an accurate volume of a droplet in order to perform infusion with an accurate amount, and an infusion device having the function.

  In a current general infusion device, a drop sensor using an infrared sensor that detects a drop is used to detect a drop from the tip of the drop nozzle of the drip tube and drop the droplet. Under the premise that the number of droplets is counted and the volume of each droplet is the same, the amount of liquid to be injected and the liquid injection speed are calculated, and the infusion pump is controlled by feedback control.

  By the way, the volume of each droplet may vary depending on the type of liquid throwing, the solid difference of the drip tube used, the liquid throwing speed, and the like (see Non-Patent Document 1). For example, when an anticancer agent whose number of cases has been rapidly increasing in recent years is dispensed, an anticancer agent having a volume difference of ± 10% or more of the drop volume tolerance of the drip tube used depending on the type of the anticancer agent has come to be administered. It was. Specifically, the change in the droplet volume is 30 to 80% minus depending on the dosage type. On the other hand, in the Pharmaceutical Affairs Law, an error of ± 10% is only allowed as the allowable accuracy according to each condition. For this reason, nurses and the like confirm the flow rate correction value according to each anticancer agent, and specifically, if the change in droplet volume is 30 to 80% minus, the normal flow rate setting value For example, it is necessary to correct the flow rate setting to 130 to 180%, and the possibility of generating a human error is increased because the setting is adjusted to the correction value.

  On the other hand, a technique for calculating the volume of a droplet has also been proposed (Patent Document 1). In Patent Document 1, a two-dimensional image sensor that obtains a plurality of pieces of photographing data is used as a drop sensor, and an upper detection sensor and a lower detection sensor are provided as a plurality of two-dimensional image sensors. The upper detection sensor is set at a position where the liquid pool grows from the tip of the dropping nozzle and exceeds the residue after falling as a droplet, and the lower detection sensor is constricted when the droplet drops from the tip of the dropping nozzle. The liquid droplet immediately after being dropped from the dropping nozzle of the chemical liquid is determined by determining that a liquid droplet has dropped from the dropping nozzle based on the photographing data. The image data is specified, and the volume of the droplet of the image data is calculated.

Japanese Patent No. 55839939

Visualization Society of Japan Vol.26 No.7 (July 2006) pp.62-68 High-speed photography of droplet formation process Kotaro Sato, Tomomi Hirose, Kouji Furuya

  However, in order to calculate and estimate the volume of each droplet more accurately without assuming that the volume of the droplet is the same, as described in Patent Document 1, the liquid is set in an optimum state for estimating the droplet volume. Although it is necessary to capture the moment when the liquid drops, it is generally not easy to determine that a liquid droplet has fallen off the dropping nozzle. In the first technique, two of the upper detection sensor and the lower detection sensor are used, and the image data of the droplet immediately after dropping from the dropping nozzle is specified from a plurality of imaging data (including moving images). Complex processing by structure is required.

  Therefore, the present invention estimates the volume of a droplet while simplifying the size and size without complicating the structure and processing when estimating the volume of the droplet in order to infuse a patient with an accurate amount. In addition, an object of the present invention is to provide a droplet volume estimation device that calculates accuracy as much as possible, and an infusion device that has the function and infuses a patient with an accurate amount as close as possible to an actual measurement value.

  According to a first aspect of the present invention, there is provided a droplet volume estimation device for estimating a droplet volume when a chemical solution in a drip tube is dropped as a droplet separated from an upstream side of the chemical solution by a dropping nozzle. Drop detection means for detecting that the liquid drops are separated from the upstream side of the chemical solution; and drops by a plurality of past successive drops detected by the drop detection means A measuring unit that measures the time interval of the liquid droplets, and a droplet time point that is determined by estimating a time point that the liquid droplet is separated from the upstream side of the chemical solution in the future based on the time interval measured by the measuring unit Determining means; imaging means capable of imaging the state of the droplet at the time when the droplet is determined to be a droplet by the droplet time determining means; and an image of the droplet based on the captured image obtained by the imaging means. An estimation means for calculating and estimating the volume; Those were example. Here, in the first aspect of the present invention, imaging is not always performed at the moment when droplets are actually formed, but is determined by estimating the timing at which droplets are considered from the time interval between droplets. Although it is to be imaged, volume estimation can be performed as accurately as possible from one captured image obtained in a droplet state or at least a state close to a droplet, and calculation processing for volume estimation is not complicated. It can be done.

  Note that the number of the past plurality of droplets is required to be at least three. This makes it possible to measure the time interval between at least two drops and reveals the trend. For example, when this trend satisfies a predetermined criterion, it is possible to more reliably estimate and determine the time point at which the liquid droplet is regarded as the droplet, and if the image of the droplet at that time is captured by the imaging means, An image at the time of becoming a droplet or an image close to the time of becoming a droplet can be obtained.

  According to a second aspect of the present invention, the chemical solution in the drip tube drops into droplets separated from the upstream side of the chemical solution by the dropping nozzle, and drops on the downstream side via the infusion tube. A liquid transfusion device that infuses a patient at a flow rate according to a predetermined flow rate condition, and estimates a droplet volume when the liquid drops are separated from the upstream side of the drug solution. The liquid drop volume estimation means includes a drop detection means for detecting that the liquid drop is separated from the upstream side of the chemical solution, and is detected by the drop detection means. A measuring unit that measures a time interval of dropping by a plurality of continuous droplets in the past, and a droplet that is separated from the upstream side of the future chemical solution based on the time interval measured by the measuring unit. A droplet time point determination means for determining a time point to be considered, and An imaging unit capable of imaging the state of the droplet at the time when the droplet is determined to be a droplet by the droplet time determination unit, and calculating and estimating the volume of the droplet based on a captured image obtained by imaging by the imaging unit And adjusting the flow rate of the drug solution passing through the infusion tube based on the droplet volume estimated by the estimation unit in order to infuse the patient with a flow rate according to the predetermined flow rate condition. A flow rate adjusting means is provided.

  In the second aspect, the operation of the operation button is used as a trigger, and in response thereto, the droplet volume estimation means operates to estimate the droplet volume and the flow rate adjustment means operates to estimate the volume. You may adjust the flow volume of the chemical | medical solution which passes an infusion tube based on the made volume. Moreover, it is good also considering that the trend of the time interval of drop falls satisfy | fills the predetermined reference | standard instead of setting it as a trigger that the operation button was operated.

  According to the present invention, a plurality of pieces of image data (including moving images) captured using a plurality of imaging units are not required for a single droplet drop, and a time interval between past droplets is used. It is only necessary to obtain image data for estimating a volume by one-shot imaging with one imaging means while deriving a droplet time point estimated to be a moment when a droplet is formed in the future. Accordingly, it is possible to obtain the accuracy of the estimation of the volume of the liquid droplets with a simple configuration and processing. In particular, if the trend of the drop time interval is derived from a plurality of drop time intervals, such as the last three drops, for example, the moment when the droplets become in line with the trend of the drop time interval, The specific accuracy of the estimated droplet point is increased, and the volume can be estimated with higher accuracy. Thereby, it becomes possible to perform infusion to a patient with an accurate amount close to an actual measurement value.

It is a general view which shows the state which uses the infusion injection | pouring system in embodiment of this invention. It is a perspective view which shows the main body of the automatic infusion apparatus of the infusion system of FIG. It is the figure which showed the state which mounts the drip tube shown with the broken line to the main body of the automatic infusion apparatus of FIG. It is the schematic of the SS cross section of FIG. It is a figure which shows the positional relationship of the drip tube of FIG. 4, an imaging sensor (camera), and a drop sensor. It is a figure for demonstrating the state of the droplet imaged with the imaging sensor (camera) of FIG. It is a block diagram which shows the control means of the automatic infusion apparatus of FIG. 2, and the structure relevant to it. It is a flowchart which shows the operation | movement of the whole automatic infusion apparatus of FIG. FIG. 9 is a flowchart for explaining (step 10) to (step 16) in the overall flow chart of FIG. 8, showing an example in which the liquid dropping is continued from the liquid droplet dropped from the liquid droplet nozzle of FIG. 5. FIG. It is the graph which showed an example of the change of the droplet size by a flow rate.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited thereto.

  FIG. 1 is an overall view showing a state in which the infusion system according to the embodiment of the present invention is used. Here, the infusion system 1 is of a natural fall type.

  The infusion system 1 includes an infusion set 5 connected to the infusion container 3 and an automatic infusion device 7. The infusion container 3 is suspended from the top of the infusion stand 9. The automatic infusion device 7 is attached to an infusion stand 9 by an attachment arm 10. The infusion set 5 includes an introduction needle 11 connected to the infusion container 3, an infusion cylinder 15 connected to the introduction needle 11 via a tube 13a, a manual clamp 17 connected to the infusion cylinder 15 via a tube 13b, and a manual clamp 17 And an infusion needle 19 connected via a tube 13c. The manual clamp 17 is for adjusting the flow rate of the infusion set 5. The infusion needle 19 is inserted into a patient's arm or the like.

  FIG. 2 is a perspective view showing the main body of the automatic infusion device of the infusion system of FIG. FIG. 3 is a view showing a state in which a drip tube indicated by a broken line is attached to the main body of the automatic infusion device of FIG. FIG. 4 is a schematic view of the SS cross section of FIG. FIG. 5 is a diagram showing the positional relationship among the drip tube, the image sensor (camera) and the drop sensor in FIG.

  As shown in FIGS. 2 and 3, here, the drip tube 40 is mounted so as to be wrapped in the main body of the automatic infusion device 30 from three directions.

  The automatic infusion device 7 is provided with a drip tube mounting portion 21 to which the drip tube 15 is mounted. The drip tube mounting portion 21 is provided with a drip tube pressing portion 23. In addition, the automatic infusion device 7 is provided with a drip tube hanger 24 at the top, and a tube door 25 at a lower position of the drip tube mounting portion 21. The tube door 25 can position and hold the tube 13b. The tube door 25 further serves not only to position the tube 13b but also to ensure that the drip tube 15 connected to the tube door 25 is properly mounted at an appropriate position.

  Further, in the automatic infusion device 7, a drop sensor 27 is provided at a position lower by a height h from the chemical solution outlet 16 which is the tip of the droplet nozzle of the drip tube 15, as shown in FIG. The drop sensor 27 detects a drop of the chemical liquid that falls as a droplet. Here, the height h is 16 mm ± 1.5 mm in the current existing product. Further, the automatic infusion device 7 is also provided with an image sensor 26 capable of photographing the state of droplets being formed into droplets at the chemical solution outlet 16.

  Further, the automatic infusion device 7 is provided with an operation panel 28, which includes an LED display unit 29, an alarm display unit 31, a fixing hook 33, an LCD display unit 35, a power key 37, a liquid volume key 39, a time / flow rate key 41, An up key 43, a down key 45, a start key 47, a stop / alarm stop key 49, an open key 51, a volume key 53, an infusion set key 55, and a flow rate adjustment unit (tube clamp) 57 are provided.

  About the LED display part 29, the alarm display part 31, and the LCD display part 35, the display as needed is performed. The liquid volume key 39, the time / flow rate key 41, the up key 43, the down key 45, the start key 47, the stop / alarm stop key 49, the release key 51, the volume key 53, and the infusion set key 55 are on the automatic infusion device 7 side. It is operated in order to set conditions for infusion injection, and is set before the automatic infusion device 7 operates. The flow rate adjusting unit (tube clamp) 57 adjusts the flow rate flowing through the tube 13b.

  FIG. 6 is a diagram for explaining a state of a droplet imaged by the imaging sensor (camera) of FIG. FIG. 7 is a block diagram showing the control means of the automatic infusion device of FIG. 2 and the configuration related thereto. Hereinafter, image data captured by the image sensor 26 will be described.

  First, the imaging sensor 26 is expected to image the separation state, which is the moment when the droplet is in the state of FIG. This is because the state of the droplet can be regarded as a two-dimensional circular state in the two-dimensional image data at the moment when it becomes a droplet, and it requires complicated calculation processing to estimate the volume of the droplet. This is because it is possible to estimate the volume closer to the actual measurement.

  The automatic infusion device 7 does not perform image analysis by capturing a moving image or a plurality of image data at the moment of the separation state in which droplets are formed as shown in FIG. Is detected, the time interval is measured, and based on the time interval and the height of h, it is estimated and determined. In the one-shot imaging by the imaging sensor 26, it is expected to capture the state of FIG. Here, as a process of forming droplets toward the separated state shown in FIG. 6E, necking shown in FIG. 6A, FIG. 6B, FIG. 6C, and FIG. There is a state. Therefore, even if the automatic infusion device 7 cannot perform imaging in the state of FIG. 6 (E), imaging is performed in the state of FIG. 6 (D) as close to FIG. 6 (E) as possible by determining the imaging timing described above. As described above, the time point at which it is considered to be a droplet is determined by estimation. Here, when the image is captured in the state of FIG. 6D, the volume estimation is performed by performing arithmetic processing using approximation or the like for estimation. Note that the volume estimation in this state is ± 10% of the flow rate measurement (ml / h) depending on the type of chemicals not approved by the Pharmaceutical Affairs Law, compared to the case where all the droplets are assumed to have the same volume. In view of the situation in which fluctuations in the volume may occur, it is considered that there is a high possibility that volume estimation closer to the actual measurement can be performed even with the volume estimation in the state of FIG.

  In order to accurately determine the point of time when the liquid droplet is formed, the operation button of the operation panel 28 is operated as a trigger at a timing when the time interval between the liquid droplets seems to have settled after a certain period of time, or The volume estimation may be performed by capturing an image of a droplet, using a trigger that is satisfied when the time interval between droplets is settled after a certain period of time as compared with a predetermined reference, For the previous droplets, the calculation may be performed assuming the same volume. Even if it does so, a remarkable effect will be acquired compared with the case where all are assumed to be the same volume, and the flow rate adjustment which adjusts the flow rate of the chemical solution which passes through the infusion tube is performed while satisfying the requirements of the Pharmaceutical Affairs Law. I can do it. Note that a dedicated operation button for volume estimation may be newly provided, or an existing operation button may have the function.

  Here, as the timing at which the drop time interval settles after a lapse of a certain time, at least three drops are required because a plurality of time intervals are obtained. When trying to detect a stable drop by moving to the drop-drop state, if there are preferably four drops, the trend of the time interval becomes clearer, and when the fifth drop is reached, the estimation of the moment when it becomes a drop is ensured I know it will be. In general, it has been found that the time from the start of dropping to the detection of a drop by the drop sensor is about 10 ms, and the correction of the imaging timing estimated therefrom is about ± 2 ms. This blur is a value that is difficult to judge by human visual recognition, and needless to say, it is significant to measure the time interval of dropping.

  In addition, although imaging and volume estimation may be performed for all the dropped droplets, in that case, there is a high possibility that the imaging is performed in a state before the droplets such as FIG. For this reason, as described above, it is necessary to devise in terms of the volume estimation calculation processing. In this regard, as described above, the image sensor 26 does not discriminate and capture the moment when the droplet actually becomes a droplet, but the droplet is regarded as a droplet at the time point when the droplet is dropped from the droplet drop time interval. This is due to the imaging of the converted state. That is, since it is not always possible to obtain a captured image only in a complete droplet state, it can be said that a contrivance is required in the calculation processing for volume estimation. However, the time when it is considered to be a droplet is also determined using the time interval of the droplet, and imaging is performed in the state of being a droplet or at least close to the state of being a droplet. Since volume estimation can be performed from the image, complication of calculation processing for volume estimation can be suppressed. Therefore, there is a demand for accuracy even in the Pharmaceutical Affairs Law, and in the medical field where the human body is affected, the volume estimation is much more accurate than when the conventional volume is assumed to be the same, and multiple cameras may be used. The accuracy of volume estimation can be obtained with sufficient accuracy required in the field, without the need to accurately detect the moment when a droplet is formed with complicated structure and processing by obtaining multiple images (movies). It can be said that the advantage is great in that the structure and processing can be simplified and the size can be reduced.

  The automatic infusion device 7 has a configuration as shown in FIG. 7 in order to perform the above processing. The droplet drop sensor 27 is connected to the control means 65, and the image sensor 26 is also connected. Further, an input unit 67, a display unit 69, a calculation unit 71, a clock unit 73, a sound source unit 75, and a memory 77 are connected to the control unit 65. These input means 67, display means 69, calculation means 71, clock means 73, sound source means 75, memory 77 are the production date / time of the infusion set, the position and number of the side tube, the material, the type of bottle needle, the drip tube This means is required for processing such as inputting information about the drop amount (drops / ml).

  The drop sensor 27 is provided with a light emitting part 27a and a light receiving part 27b, and it is detected that a liquid drop of the chemical liquid drops between them. A detection signal is input to the control means 65. The control means 65 controls the operation of the clock means 57 based on the detection signal of the drop sensor 27 so that the time interval of drop is measured. The measured time interval is stored in the memory 77. The memory 77 also stores the above height h as data.

  Based on the time interval and height h stored in the memory 77 by the computing means 71, the image sensor 26 captures the liquid droplets in order to capture the separation state representing the state at the time when the liquid droplets became the liquid droplets of FIG. Estimate and determine the time point at which it is considered that the image has become, and take an image at one-shot imaging timing. The computing means 71 computes and estimates the volume of the droplet based on the imaging data. A volume estimation device is configured by such means for estimating the volume of the droplet, and is incorporated in the automatic infusion device 7.

  A driver 81 for driving the actuator 79 is connected to the control means 65, and the actuator 79 is driven by the control means 65 to adjust the flow rate by the flow rate adjusting unit (tube clamp) 57. The operation of the control means 65 is enabled by a power supply unit 83 having a boost converter 83a. Specifically, the flow rate adjustment is performed by intermittently repeating the narrow pressure and release with the pressing body according to the estimated value of the volume of the droplet. As a result, the actual flow rate is corrected, and it is possible to infuse the patient with an amount closer to the actually measured value.

  FIG. 8 is a flowchart showing the overall operation of the automatic infusion device of FIG. FIG. 9 is a flowchart for explaining (step 10) to (step 16) in the overall flow chart of FIG. 8, in the case where the liquid drop is continued from the liquid drop obtained from the liquid drop nozzle of FIG. It is the flowchart which showed the example.

  In step (step 1), an infusion set is set. This infusion set is set by operating the infusion set key 55 in FIG. In step (step 2), the infusion scheduled amount is input. This input is performed by the input means 67 in FIG. 7 by operating the liquid volume key 39 in FIG. In step (step 3), an input of a flow rate per hour is performed. This input is performed by the input means 67 of FIG. 7 by operating the time / flow rate key of FIG. In step (step 4), the flow rate per unit time is calculated. This calculation is performed by the calculation means 71 of FIG. In step (step 5), the drop interval is determined. In step (step 6), the infusion set information is stored, and then the processing after the infusion set is attached is performed.

  In step (step 7), the tube clamp 57 is closed, but in step (step 8), the manual clamp 17 is opened, in step (step 9), the tube clamp is opened, and in step (step 10), the droplet drops. Is detected. Hereinafter, with reference also to FIG. 9, the drop drop detection is performed by the drop sensor 27 of FIG. 7. In step (step 11) of FIG. 8, it is determined whether or not the flow rate is within ± 10%. If it is not within ± 10% of the set flow rate, processing such as normalizing the infusion line or raising the infusion bag is performed in step (step 12), and loop processing is performed so that it is within ± 10% of the set flow rate. Done. In a step (step 13) after this process, the droplet volume is calculated. This step (step 13) includes the processing of steps (step 131) to (step 136) in FIG. 9 as more specific processing.

  In step (step 131) in FIG. 9, the clock means 73 measures the drop interval based on the detection by the drop sensor 27 in FIG. In step (step 132), it is determined whether there is a drop interval trend. This determination requires detection of at least 3 drops. There is a trend of drop intervals, and when the trend settles, in step (step 133), the calculation means 71 can determine and determine the timing of image acquisition from the drop interval and the height h described above. . This timing is a timing regarded as the moment when the droplet is formed. Here, instead of observing the moment when an actual droplet is formed by image processing, the moment when it becomes a droplet is determined by using the time interval of the droplet to determine the moment when it is considered to be a droplet. The point that has been confirmed is an important point. The control means 65 controls the operation so that the image sensor 26 captures an image at the determined timing, and in step (step 134), one-shot imaging can be performed in a separated state or a state close thereto. ing. In step (step 135), a volume calculation process is started from the obtained image by the calculation means 71 to determine the estimated volume. In step (step 136), a drop interval according to volume calculation is determined.

Returning to FIG. 8, it is determined in step (step 14) whether or not it is within ± 10% with respect to the reference droplet volume. If it is not within ± 10% with respect to the reference droplet volume, in step (step 15). The flow rate adjustment unit (tube clamp) 57 operates to adjust the flow rate, and the drop drop interval is adjusted in accordance with the droplet volume calculation. Specifically, for example, if the reference value of the droplet volume falling from the droplet nozzle is 20 drops / ml and 20 drops is set as 1 ml, the volume of one drop is 50 mm ³ , ± volume Assuming that allow an error of 10% whether beyond the scope of 45mm ³ ~55mm ³ is determined. If it is within ± 10% with respect to the reference droplet volume, the infusion is continued as shown in step (step 16). Note that the processing of steps (step 14) to (step 16) in FIG. 8 is expressed in another way as shown in steps (step 137) to (step 139) of FIG.

  Hereinafter, a device for further improving the accuracy will be described in consideration of a change in the droplet size due to the flow rate based on the error in the integrated amount accompanying the flow rate change.

  FIG. 10 is a graph showing the trend of measuring the error of the integrated amount accompanying the flow rate change using a general 20 drops / mL infusion set. Here, the horizontal axis is the flow rate, and the integrated amount error corresponding to the flow rate is set on the vertical axis, and the integrated amount error due to the flow rate change is represented.

  Referring to FIG. 10, since it is not easy to measure one of the droplets, an attempt is made to determine the size of the droplet based on a certain integrated amount according to each flow rate. Here, the integrated amount can be measured by counting the number of droplets for a certain time. While the droplet size error of infusion sets approved for medical use is determined to be within ± 10%, the ± 0% flow rate set by each infusion set manufacturer is approximately 100 mL / h to around 200 mL / h (200 mL / h in FIG. 10) and there is a variation. The variation occurs even when the manufacturer is different, and even if it is the same product, it also occurs as individual differences. In addition, due to each infusion set manufacturer and the individual differences, the fluctuation width of the error corresponding to the flow rate setting varies.

  It can be said from FIG. 10 that the droplet size increases as the flow rate increases, and the droplet size tends to decrease as the flow rate decreases. The droplet size at a flow rate of 200 mL / h shown in FIG. 10 is ± 0%, but when the infusion set is used, the correction value at 400 mL / h is −6%. Conversely, the correction value at 10 mL / h is + 4%, and it can be said that the correction of the droplet size when the flow rate changes can be kept within ± 5% of the target. This can be said to be a viewpoint that can improve the accuracy to ± 5% compared to ± 10% in FIG.

  This will be described with reference to FIG. 6A to 6D, the change from the necking state in which the shape changes to the separation state to the separation state (E) has a short drop interval (for example, 2 drops / second: 20 drops / mL infusion set). If the flow rate is 360 mL / h), the speed of the change will naturally become faster, and it will be necessary to obtain an instantaneous photographing timing for a shorter time. The force pulling the tension downward acts strongly and becomes vertically long. On the other hand, when the drop interval becomes too long (for example, 1 drop / 9 seconds: 20 mL / h in the case of an infusion set of 20 drops / mL), the necking state in which droplets are formed as shown in FIGS. It takes a long time to change the shape of the image, and it is assumed that it is difficult to grasp the trend of the accurate time interval for measuring the shooting timing of the separation state (E), and it requires a corresponding measurement time, which is practical. It is desirable to set a correct measurement flow rate (time interval).

  In other words, the measurement of the past time interval is 1 drop / 1 second to 1 drop / 3 second (with a 20 drop / mL infusion set, 1 drop / 1 second is 180 mL / h, and 1 drop / 3 second is 60 mL / h. By measuring a fixed trend within a range of approximately, it is possible to stabilize the drop shape and increase the specific accuracy of the drop point estimated as the moment when the drop was formed. By such a technique, it can be made more accurate.

DESCRIPTION OF SYMBOLS 1 ... Infusion system, 3 ... Infusion container, 5 ... Infusion set, 7 ... Automatic infusion device, 9 ... Infusion stand, 10 ... Mounting arm, 11 ... Introducing needle 13a, 13b, 13c ... tube, 15 ... drip tube, 16 ... medicinal solution outlet, 17 ... manual clamp, 19 ... infusion needle, 21 ... drip tube mounting part, 23 ... Drip tube presser, 24 ... Drip tube hanger, 25 ... Tube door, 26 ... Image sensor, 27 ... Drip sensor, 27a ... Light emitting unit, 27b ... Light receiving part, 28 ... Operation panel, 29 ... LED display part, 31 ... Alarm display part, 33 ... Fixed hook, 35 ... LCD display part, 37 ... Power key, 39 ..Liquid volume key, 41 ... Time / flow rate key, 43 ... Up key, 45 ... Down key, 47 ... start key, 49 ... stop / alarm stop key, 51 ... release key, 53 ... volume key, 55 ... infusion set key, 57 ... flow rate adjustment section (tube Clamp), 65 ... control means, 67 ... input means, 69 ... display means, 71 ... calculation means, 73 ... clock means, 75 ... sound source means, 77 ... memory 79 ... Actuator, 81 ... Driver, 83 ... Power supply, 83a ... Boost converter

Claims (2)

A droplet volume estimation device for estimating a droplet volume when a drug solution in a drip tube drops as a droplet separated from the upstream side of the drug solution by a dropping nozzle,
Drop-drop detecting means for detecting that the liquid drops are separated from the upstream side of the chemical liquid;
A measuring means for measuring a time interval of dropping by a plurality of past successive drops detected by the dropping detection means;
A droplet time point determination unit that estimates and determines a time point that is considered to be a droplet separated from the upstream side of the future chemical solution based on the time interval measured by the measurement unit;
An imaging unit capable of imaging a state of a droplet at a time point regarded as a droplet by the droplet time point determination unit;
A droplet volume estimation apparatus comprising: an estimation unit that calculates and estimates a volume of the droplet based on a captured image obtained by imaging by the imaging unit. The liquid medicine in the drip tube drops as a liquid droplet separated from the upstream side of the liquid medicine by the dropping nozzle, and the liquid medicine dropped on the downstream side corresponds to a predetermined flow rate condition via the infusion tube. An automatic infusion device that infuses a patient with a flow rate,
A droplet volume estimating means for estimating a droplet volume when dropping from the upstream side of the chemical solution as a separated droplet;
The droplet volume estimation means includes
Drop-drop detecting means for detecting that the liquid drops are separated from the upstream side of the chemical liquid;
A measuring means for measuring a time interval of dropping by a plurality of past successive drops detected by the dropping detection means;
A droplet time point determination unit that estimates and determines a time point that is considered to be a droplet separated from the upstream side of the future chemical solution based on the time interval measured by the measurement unit;
An imaging unit capable of imaging a state of a droplet at a time point regarded as a droplet by the droplet time point determination unit;
An estimation unit that calculates and estimates the volume of the droplet based on a captured image obtained by imaging by the imaging unit;
In order to infuse the patient with a flow rate according to the determined flow rate condition, the flow rate adjusting means adjusts the flow rate of the drug solution passing through the infusion tube based on the droplet volume estimated by the estimation means, Automatic infusion device.