JP3130658B2 - Blockage detection device for infusion pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is incorporated in an infusion pump provided with a pump unit for moving a liquid passing through a flexible tube while sequentially pressing the tube, and closing the tube on the downstream side of the pump unit. The present invention relates to a blockage detection device for detecting a blockage.

[0002]

2. Description of the Related Art Conventionally, various types of infusion pumps have been used for injecting a drug solution into a living body or performing automatic infusion, etc., which is disclosed in Japanese Patent Publication No. 61-55,393. As described above, a peristaltic finger type infusion pump is known.

As shown in FIG. 7, this type of infusion pump 10 is provided with a tube mounting portion 12 on the front surface of a main body 11 for mounting a flexible tube connected to an infusion bag or the like. . The tube mounting section 12 is provided with a pump section 13 for moving a liquid passing through the tube, and a door 14 facing the pump section 13 is attached via a hinge 15 so as to be openable and closable. Furthermore, the main body 1
An operation unit 16 for setting various operating conditions and a display unit 17 for displaying an operating state and the like are provided on the front of the unit 1. Further, as shown in FIG.
A back plate 19 that presses the tube 18 along the direction toward the pump unit 13 is provided on the inner surface 14 a facing the pump unit 13. Between the back plate 19 and the door inner surface 14a, a spring 20 for urging an elastic force for pressing the back plate 19 toward the pump portion 13 is attached.

[0004] As shown in FIG.
A plurality (for example, six) of fingers 25 movable forward and backward with respect to the mounted tube 18;
5 that slidably holds the casing 5. The casing 26 is composed of a pair of casing members 27 which are abutted with each other.
A holding groove 28 for slidably holding each finger 25 is formed in a shelf shape. In the casing 26, a support shaft 29 is rotatably mounted via a bearing 30, and a plurality of (for example, six) eccentric cams 31 are shifted on the support shaft 29 by a predetermined angle. Is fixed. The finger 25 has a substantially plate-like shape, and has a cam hole 32 with which the eccentric cam 31 slides. One end of a spindle 29 protruding from the casing 26 has a stepping motor,
A rotation drive unit (not shown) including a timing belt and the like is connected.

[0005] Then, the rotation driving means is operated to operate the support shaft 2.
When the eccentric cam 9 is driven to rotate, each of the eccentric cams 31 fixed to the support shaft 29 with the phase shifted is rotated while sliding on the inner peripheral surface of the cam hole 32 of the corresponding finger 25. As a result of this cam action, each finger 25 is moved
8, the finger 25 starts moving forward sequentially from the top, and moves to the forward limit.
The tube 18 is pressed in between to close the flow path of the tube 18. The finger 25 that has moved to the forward limit is
As the support shaft 29 further rotates, it moves toward the backward limit, and the blockage is released. In this way, by repeating the operation of sequentially moving from the finger 25 located above to the forward limit, the point of closing the tube 18, that is, the closing point 18 a sequentially moves downward along the longitudinal direction of the tube 18, The liquid in 18 is infused from the suction side to the discharge side.

In the course of performing an infusion in this way,
A part of the tube 18 on the downstream side of the pump unit 13 is bent or twisted, or a needle or the like attached to the tip of the tube 18 is clogged, so that the flow path of the tube 18 is blocked, and the internal pressure of the tube 18 increases. There was something to do.
If such an increase in the internal pressure of the tube is left untreated, the tube 18 may be damaged.
The tube mounting part 12 of the infusion pump 10 has a pump part 1
A blockage detection mechanism 35 for detecting blockage of the tube 18 on the downstream side of 3 is provided.

The blockage detection mechanism 35 is configured to detect blockage of the tube 18 by detecting expansion of the tube 18 due to an increase in the internal pressure of the tube, and uses a link mechanism or a strain gauge. Those used have been proposed.

Blockage detection mechanism 35 using link mechanism
A part of the link mechanism is brought into contact with the outer surface of the tube 18, the expansion amount of the tube 18 caused by an increase in the internal pressure of the tube is increased by the link mechanism, and the displacement of a moving member provided in the link mechanism is detected. Thereby, it is configured to detect whether or not the tube 18 is closed.

The blockage detecting mechanism 35 using a strain gauge has a strain gauge attached to a leaf spring or the like that comes into contact with the outer surface of the tube 18 so that the output of the strain gauge at the start of operation and the strain during operation can be obtained. By detecting an output difference from the output of the gauge, it is configured to detect whether or not the tube 18 is closed.

[0010]

By the way, even when a certain fixed internal pressure acts on the tube 18, the bulging amount thereof changes as the temperature around the tube 18 changes. General vinyl chloride tubes and silicone tubes tend to soften at high temperatures and conversely harden at low temperatures. For this reason, even when a constant tube internal pressure is applied, the tube 18 easily expands when the temperature increases, and conversely, the tube 18 does not easily expand when the temperature decreases.

However, the conventional blockage detection mechanism 35 accurately detects the blockage of the tube 18 in response to the temperature change because the blockage detection level is kept constant even when the temperature around the tube 18 changes. I couldn't. That is, when the temperature around the tube 18 becomes higher than the design temperature when the blockage detection level is determined,
Since the tube 18 is easily swelled, there is a possibility that it is detected that the tube 18 has been blocked even though the internal pressure of the tube has not reached the predetermined blocking detection pressure. Conversely, when the temperature around the tube 18 becomes lower than the design temperature, the tube 18 hardly expands. Therefore, even though the tube internal pressure has reached the predetermined blockage detection pressure, blockage has occurred. Otherwise, it may be detected.

Accordingly, an object of the present invention is to provide a blockage detecting device capable of accurately detecting tube blockage in response to a change in the temperature of an environment in which an infusion pump is used. I do.

[0013]

According to the present invention, there is provided an infusion pump having a pump section for moving a liquid passing through a flexible tube while sequentially pressing the tube. A blockage detection device that detects blockage of the tube on the downstream side of a pump unit,
Expansion detection means for detecting expansion of the tube due to an increase in tube internal pressure due to blockage, temperature detection means for detecting a use environment temperature of the infusion pump, and blockage based on the use environment temperature detected by the temperature detection means Control means for changing a detection level and comparing the blockage detection level with the expansion of the tube detected by the expansion detection means to determine blockage of the tube; and blockage detection for an infusion pump. Device.

[0014]

The control means changes the blockage detection level based on the use environment temperature detected by the temperature detection means, and compares the changed blockage detection level with the expansion of the tube detected by the expansion detection means. Then, it is determined whether or not the tube is blocked. As described above, since the presence or absence of blockage is determined while changing the blockage detection level, even if the temperature of the environment where the infusion pump is used changes, tube blockage detection is performed in response to this temperature change. Can be done accurately. For example, when the environmental temperature increases, the blockage detection level is changed to a higher level, so that the blockage of the tube can be detected at a predetermined blockage detection pressure corresponding to the tube that has easily expanded. Further, when the environmental temperature becomes low, the blockage detection level is changed to a lower level, so that the blockage of the tube can be detected at a predetermined blockage detection pressure corresponding to the tube that has become difficult to inflate.

[0015]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a view showing an example of use of an infusion pump in which a blockage detection device of the present invention is incorporated, and FIGS.
FIG. 8 is a cross-sectional view of a main part showing an operation state of the blockage detection device shown in FIG. 1, wherein members common to those shown in FIGS. 6 and 7 are denoted by the same reference numerals, and a description thereof is partially omitted. .

As shown in FIG. 1, in the medical field,
An infusion system 5 for infusing a parenteral liquid such as a nutrient solution, a drug solution, or a physiological saline solution to the patient 8 in order to administer these liquids.
Is used. The infusion system 5 includes an infusion bag 6 for storing a nutrient solution and the like, and an infusion pump 40 for infusing the nutrient solution and the like. A flexible tube 18 is connected to the infusion bag 6 via a drip tube 7, and a tube mounting portion 12 to which the tube 18 is mounted is provided on the front surface of the main body 11 of the infusion pump 40. This tube mounting part 1
2 includes a tube 1 downstream of the pump unit 13.
8 is provided with a blockage detection device 41 for detecting blockage.

FIG. 2 shows a blockage detecting device 41 of this embodiment.
As shown in (A) and (B), an expansion detecting means 39 for detecting expansion of the tube 18 due to an increase in the internal pressure of the tube due to the blockage is provided, and the expansion detecting means 39 is provided when the tube 18 is closed. The tube 18 has a moving member 42 that moves as the tube 18 expands. Main unit 1
1 includes a tube mounting groove 43 in which the tube 18 is housed.
And a through hole 44 communicating with the tube mounting groove 43, and the movable element 42 is movably inserted into the through hole 44. When the infusion bag 6 is exchanged, a part of the liquid medicine may leak out and may reach the tube mounting groove 43 along the outer surface of the tube 18. A diaphragm rubber 45 is attached to the tube mounting groove 43 in order to prevent the intrusion into the main body 11 through the gap between the tube mounting groove 43. Therefore, the distal end of the moving member 42 is in contact with the outer surface of the tube 18 via the diaphragm rubber 45.
A holding member 46 is provided on the door inner surface 14a in order to hold the tube 18 in the tube mounting groove 43 between the tube 18 and the movable member 42. The holding member 46 is attached to the door inner surface 14a.
The first plate spring 47 screwed to the
It is configured by fixing the pressing plate 48 facing the third.

The mover 42 has a cylindrical shape and is fixed to a second leaf spring 49 screwed to the main body 11. The second leaf spring 49 holds the moving plate 42 against the holding plate 4.
It is resilient in the direction toward 8. The strength of the elastic force of the second leaf spring 49 is larger than the elastic force of the material of the tube 18 itself, and inhibits the smooth expansion of the tube 18 when the tube 18 is closed and the internal pressure of the tube increases. Not set to a size. The resilience of the first leaf spring 47 of the holding member 46 is the same as that of the second leaf spring 4.
9, the pressing plate 48 is set to a size that does not separate from the tube mounting groove 43 even when the tube 18 is closed and the tube 18 expands. Therefore, at the time of operation start, which is a reference for blockage detection, as shown in FIG.
Is held between the movable member 42 and the pressing plate 48 in a state where the pressing member 48 is crushed to a predetermined dimension L equal to or less than the outer diameter dimension. On the other hand, when the tube 18 is closed, the tube 18 expands by a size ΔL in accordance with the increase in the tube internal pressure, as shown in FIG. It moves by ΔL upward in the drawing against the elastic force of the leaf spring 49.

The configuration for urging the movable element 42 to resiliently is not limited to the illustrated second leaf spring 49, but may be, for example, a spring or the like. Further, the shapes and structures of the moving element 42 and the holding member 46 are not limited to those shown in the drawings, and can be changed as appropriate. Further, a configuration may be employed in which the strength of the resilient force urged by the moving element 42 can be adjusted.

The expansion detecting means 39 of the blockage detecting device 41
Further, when the tube 18 is closed,
A displacement amount detecting means 50 for detecting a moving amount, that is, a displacement amount, of the moving element 42 that moves as the element expands.
The displacement amount detecting means 50 is composed of, for example, a magnetic sensor, and is a magnet 51 that moves together with the moving element 42.
And a magnetic element 52 that outputs a signal corresponding to a change in the strength of the magnetic field due to the movement of the magnet 51. The magnet 51 is held by an adjustment screw 53 attached to a screw hole (not shown) formed in the second leaf spring 49, and heads toward the head of the adjustment screw 53 by a spring 54 provided between the magnet 51 and the second leaf spring 49. It is bounced in the direction. Therefore, by rotating the adjusting screw 53, the holding position of the magnet 51 can be adjusted vertically in the drawing. On the other hand, the magnetic element 52 is separated from the magnet 51 via a bracket 55 with a predetermined gap therebetween.
It is fixed to. The magnetic element 52 outputs a signal corresponding to a change in the strength of the magnetic field so as to draw a predetermined curve according to the positional relationship with the magnet 51. In order to accurately detect the displacement of the magnet 51, When the 51 moves from the initial position to the closed position, it is necessary to obtain a change in the output voltage from the magnetic element 52 within a linear range. For this reason, as described above, the holding position of the magnet 51 can be adjusted so as to fall within the linear range.

The infusion pump 40 is usually operated at about 10 ° C.
Although it is used in a temperature range of about 40 ° C., as shown in FIG. 3, even when a constant tube internal pressure Pi acts, the hardness of the tube 18 changes in the temperature range and the swelling of the tube 18 occurs. The amount ΔL will be different. FIG.
As is clearer, when the temperature increases, the tube 18 softens and swells easily.
8 tend to harden and hardly swell.

As described above, since the temperature greatly affects the swelling amount of the tube 18, the blockage detecting device 41 of the present embodiment has the temperature detecting means 38 for detecting the operating environment temperature of the infusion pump 40. . This temperature detecting means 38
Is composed of, for example, a thermistor or a thermocouple. As shown in FIGS. 1 and 2, the thermistor 38 as a temperature detecting means can detect a use environment temperature of the infusion pump 40, for example, an outer surface of the main body 11, preferably the tube mounting section 12, and more preferably. Is attached to the door inner surface 14a close to the moving element 42.

FIG. 4 shows the change with respect to the temperature of the swelling ratio ΔL / Pi (the ratio of the swelling amount 内 L to the tube internal pressure Pi) obtained from FIG. As is clear from FIG. 4, the swelling ratio ΔL / Pi approximates a linear function with respect to temperature and is given by the following equation (1). ΔL / Pi = Kn · t + a (1) Here, ΔL: swelling amount of tube Pi: tube internal pressure Kn: proportional constant a: swelling ratio at 0 ° C. t: temperature (° C.)

The holding position of the magnet 51 is adjusted by an adjusting screw 53.
When the magnet 51 moves along with the expansion of the tube 18, the output voltage from the magnetic element 52 can be changed in a linear range.

At this time, the swelling amount of the tube 18 △
L is proportional to the change ΔVd in the detection voltage due to the change in resistance of the magnetic element 52, and is given by the following equation (2). ΔVd / ΔL = Km (2) where Km is a proportional constant.

From the equations (1) and (2), ΔVd = Km △ L = Km · (Kn · t + a) · Pi = a · Km · (1 + Kn / at · t) · Pi (3)

From this equation (3), if the internal pressure of the tube to be detected (blocking detection pressure) is Pth, the corresponding detection voltage ΔVth is ΔVth = a · Km · (1 + Kn / at · t) · Pth (4) Therefore, if the constants a, Km, and Kn are determined in advance by experiments or the like, it is possible to detect the presence or absence of the blockage of the tube 18 at a predetermined blockage detection pressure Pth even when the temperature changes.

FIG. 5 shows the tube 18 based on the signal from the magnetic sensor 50 and the signal from the thermistor 38.
FIG. 4 is a block diagram showing a processing circuit for determining blockage of a block.

The magnetic element 52 forms a bridge with the resistors R 1, R 2 and R 3, and a constant voltage is applied to the bridge from the constant voltage circuit 61. The movement of the magnet 51 changes the resistance of the magnetic element 52, and outputs a signal corresponding to this change to the differential amplifier 60. The differential amplifier 60
The signal from the magnetic element 52 is appropriately amplified, and an output voltage having a correlation with the tube internal pressure is output to the A / D converter 62. The A / D converter 62 converts a detection signal from the differential amplifier 60 into a digital code and outputs the digital code to a microprocessor unit 63 as control means. On the other hand, the thermistor 38 forms a bridge with the resistors R4, R5 and R6, and a constant voltage is applied to the bridge from the constant voltage circuit 64. The resistance of the thermistor 38 changes due to the temperature change, and a signal corresponding to this change is output to the differential amplifier 65. The differential amplifier 65 appropriately amplifies the signal from the thermistor 38, and outputs an output voltage having a correlation with the temperature to the A / D converter 66. In the A / D converter 66,
The signal from the differential amplifier 65 is converted into a digital code,
Output to the microprocessor unit 63. The storage means 67 is connected to the microprocessor section 63, and the above equation (4) is obtained.
In addition, a constant value and a blockage detection pressure Pth to be detected are stored. Then, the microprocessor unit 63 detects the ambient temperature based on the information from the thermistor 38, calculates ΔVth from the equation (4) based on the temperature, and calculates the ΔVth obtained by calculating the signal from the A / D converter 62. If it exceeds, it is determined that the tube 18 has been blocked. In this manner, the calculated ΔVth functions as a blockage detection level for detecting blockage, that is, a threshold value.

Next, the operation of this embodiment will be described.

When the infusion pump 40 is driven by mounting the tube 18 on the tube mounting section 12, the pump section 13 sequentially repeats the operation of sequentially moving from the upper finger 25 to the forward limit, thereby connecting the tube 18 to the tube 25. The closing point, that is, the closing point 18a sequentially moves downward along the longitudinal direction of the tube 18, and the liquid in the tube 18 is infused from the suction side to the discharge side.

At the start of operation, the blockage detecting device 41 is in the state shown in FIG.
Is held between the pressing plate 48 and the movable element 42 to which the resilient force of the second leaf spring 49 is urged, in a state of being crushed to a predetermined dimension L equal to or less than the outer diameter dimension. Further, during normal infusion, the moving element 42 and the magnet 51 do not move, and the output signal from the magnetic element 52 is constant.
Further, the microprocessor unit 63 detects the ambient temperature based on information from the thermistor 38, and calculates ΔVth from Expression (4) based on the detected temperature. Then, while the normal infusion is being performed, the microprocessor unit 63
It is determined that the signal from the A / D converter 62 does not exceed the calculated ΔVth, and it is determined that the tube 18 is not blocked.

If the flow path of the tube 18 downstream of the pump unit 13 is blocked during the transfusion,
The internal pressure of the tube 18 gradually increases. Then
As shown in FIG. 2 (B), the tube 18 which has been crushed to a predetermined size L expands by a size ΔL in response to an increase in the tube internal pressure against the elastic force of the second leaf spring. The mover is also pushed upward by the same amount in the upward direction in the figure. At this time, since the tube 18 has been crushed in advance at the start of the reference operation, the amount of expansion of the tube 18 itself can be made relatively large. The displacement amount is also relatively large. When the moving element 42 moves in this manner, the magnet 51
Also moves by the same amount, the output signal from the magnetic element 52 changes according to the change in the strength of the magnetic field due to the movement of the magnet 51. In the microprocessor section 63, A
The signal from the / D converter 62 and the calculated ΔVth are constantly compared.

When the tube internal pressure exceeds the blockage detection pressure Pth, the signal from the A / D converter 62 calculates the calculated ΔVt
h, and the microprocessor unit 63 determines that the tube 18 has been blocked. Since the ΔVth obtained from the equation (4) is compared with the signal from the A / D converter 62, even if the use environment temperature changes, the ΔVth, that is, the threshold value does not automatically change according to the change. Therefore, the blockage of the tube 18 is reliably detected at the predetermined blockage detection pressure Pth. When the blockage detection device 41 detects the blockage of the tube 18, the operation of the pump unit 13 is stopped. It is forcibly stopped or an alarm is issued. As a result, the reliability of the infusion pump 40 is increased, and the nurse can be engaged in other tasks with peace of mind, and the patient receiving the infusion can be treated with peace of mind.

As described above, according to the blockage detecting device 41 of the present embodiment, the microprocessor section 63 adjusts the temperature around the tube detected by the thermistor 38 in accordance with the temperature.
Since the blockage detection level is automatically corrected and the presence or absence of blockage is determined based on the corrected blockage detection level, even if the temperature of the environment using the infusion pump 40 is different from the design temperature, Blockage detection of the tube 18 can be accurately performed in response to a temperature change in the environment. That is, when the temperature around the tube 18 increases, the equation (4)
As is clear from FIG. 7, since the threshold value is corrected to be higher, the blockage of the tube 18 can be detected at a predetermined blockage detection pressure Pth corresponding to the tube 18 that has become easily bulged. Conversely, when the temperature around the tube 18 decreases, the threshold value is corrected to a lower value, so that the predetermined blockage detection pressure Pth corresponding to the tube 18 that has become less likely to swell.
Can detect the blockage of the tube 18.

FIG. 6 is a block diagram showing another processing circuit for judging the blockage of the tube based on the signal from the magnetic sensor 50 and the signal from the thermistor 38.

As in the processing circuit described above, the magnetic element 52
Constitute a bridge, and are driven by the constant voltage circuit 61. Further, the differential amplifier 60 appropriately amplifies the signal from the magnetic element 52 to obtain a detection signal 70. The differential amplifier 60 is adjusted so that the detection signal 70 when the tube 18 is mounted on the infusion pump 40 becomes zero. The detection signal 70 from the differential amplifier 60 is output to the comparator 71. On the other hand, the thermistor 38 forms a combined resistance RC together with the correction resistance Rs. The combined resistance Rc changes according to the following equation (5) depending on the temperature.

RC = RC0 (1−Kc · t) (5) where RC0 is the value of Rc at 0 ° C. Kc is a proportional constant.

The output Vc of the amplifier 72 connected to the thermistor 38 is given by the following equation (6).

Vc = −RF / RC · (−V) = RF / (RC0 (1−Kc · t)) · V = RF / RC0 (1 + Kc · t) · V (6) where (Kc · t) ) ² <1 where -V is a reference voltage.

Therefore, as apparent from the comparison between the equations (4) and (6), by selecting the values of RF / RC0, Kc, and V, the output Vc from the amplifier 72 becomes equal to ΔVth. Become. Therefore, the control means including the comparator 71 and the amplifier 72 converts the detection voltage 70 and the temperature-compensated Vc output from the amplifier 72 into the comparator 7.
The blockage of the tube 18 can be detected by performing the comparison in step 1, and the detection signal 73 corresponding to the blockage is output.

Even with such a processing circuit, since the temperature correction function is provided similarly to the above-described embodiment, even if the environmental temperature at which the infusion pump 40 is used is different from the design temperature. In addition, it is possible to accurately detect the blockage of the tube 18 in response to a temperature change in the environment where the infusion pump 40 is used.

Although the peristalic finger type infusion pump 40 is shown, the blockage detecting device 41 of the present invention can be incorporated in another type of infusion pump. Further, the expansion detecting means 39 is not limited to the one shown in the figure, and any structure having a conventionally known link mechanism, a strain gauge, It is good also as composition which has.

[0044]

According to the present invention, there is provided an occlusion detecting apparatus for an infusion pump, comprising: an expansion detecting means for detecting expansion of the tube due to an increase in the internal pressure of the tube due to the occlusion; And changing a blockage detection level based on the use environment temperature detected by the temperature detection unit, and comparing the blockage detection level with the expansion of the tube detected by the expansion detection unit to determine blockage of the tube. Control means, even if the environmental temperature of the infusion pump changes, the presence / absence of blockage is determined while the blockage detection level is changed accordingly. This is effective in that it can be performed accurately in response to

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of use of an infusion pump incorporating a blockage detection device of the present invention.

FIGS. 2A and 2B show the blockage detection device shown in FIG. 1, and FIG. 2A is a cross-sectional view of a main part showing an operation state at the start of operation. B) is a sectional view of a principal part showing an operating state when the tube is closed.

FIG. 3 is a graph showing the relationship between the internal pressure of a tube and the amount of swelling of the tube due to a temperature change.

FIG. 4 is a graph showing a relationship between a temperature and an expansion rate of a tube.

FIG. 5 is a block diagram showing an embodiment of a processing circuit of the blockage detection device.

FIG. 6 is a block diagram showing another embodiment of the processing circuit of the blockage detection device.

FIG. 7 is a perspective view showing the appearance of a general infusion pump.

FIG. 8 is an essential part cross-sectional view showing a general pump part incorporated in an infusion pump.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 13 ... Pump part 18 ... Flexible tube 38 ... Thermistor (temperature detection means) 39 ... Expansion detection means 40 ... Infusion pump 63 ... Microprocessor part (control means) 71 ... Comparator (control means) 72 ... Amplifier (control means)

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-1-249064 (JP, A) JP-A-2-289260 (JP, A) JP-A-1-129857 (JP, A) JP-A-4- 22368 (JP, A) JP-A 1-170248 (JP, U) JP-A 64-43937 (JP, U) JP 5-62254 (JP, U) (58) Fields surveyed (Int. Cl. ⁷ , DB name) A61M 5/00 335 A61M 5/142 A61M 5/168

Claims (1)

(57) [Claims] An infusion pump (40) having a pump section (13) for moving a liquid passing through the flexible tube (18) while sequentially pressing the flexible tube (18), wherein the pump section ( 13)
A blockage detection device that detects blockage of the tube (18) on a downstream side of the tube (18), the tube (18) associated with an increase in tube internal pressure due to blockage.
Expansion detecting means (39) for detecting the expansion of the infusion pump, a temperature detecting means (38) for detecting an operating environment temperature of the infusion pump (40), and the operating environment temperature detected by the temperature detecting means (38). Control means for changing the blockage detection level and comparing the blockage detection level with the expansion of the tube (18) detected by the expansion detection means (39) to determine the blockage of the tube (18). (71, 72)). A blockage detection device for an infusion pump, comprising: