Patent ID: 12223144

DETAILED DESCRIPTION

(Detection Device)

Hereinafter, a detection device according to embodiments of the present disclosure will be described with reference to the drawings.

In the drawings, the same or corresponding parts are denoted by the same reference characters. In the description of the present embodiment, redundant descriptions of the same or corresponding parts will be omitted or simplified appropriately.

First, an outline of an operation of abnormality detection of an infusion tube by a detection device according to the present disclosure will be described with reference toFIGS.1and2.

Although details will be described below, the detection device according to the present disclosure irradiates an infusion tube attached to the detection device with an infrared ray, receives an infrared ray reflected by the infusion tube, and generates a captured image obtained by imaging the infusion tube. The detection device detects blockage of the infusion tube and air bubbles in the infusion tube based on the generated captured image.

FIG.1is a schematic diagram illustrating a path of an infrared ray emitted from the outside of the infusion tube in a width direction toward the infusion tube. InFIG.1, a solid or broken arrow indicates an infrared ray, and the thickness of the arrow indicates the intensity of the infrared ray. Furthermore, the solid arrow indicates incident light and transmitted light of an infrared ray emitted toward the infusion tube, and the broken arrow indicates an infrared ray reflected by the infusion tube. As illustrated inFIG.1, an infrared ray emitted from the outside of the infusion tube in a width direction toward the infusion tube travels in the order of air outside the infusion tube, a side wall of the infusion tube, a liquid or air bubbles in the infusion tube, a side wall of the infusion tube, and air outside the infusion tube. At this time, a part of the infrared ray passes through a boundary between substances having different refractive indexes, and the other part of the infrared ray is reflected at the boundary between the substances having different refractive indexes. As an example, it is assumed that the side wall of the infusion tube, the liquid in the infusion tube, and the air bubbles in the infusion tube are vinyl chloride, water, and air, respectively. In this case, the refractive indexes of the side wall of the infusion tube, the liquid in the infusion tube, and the air bubbles in the infusion tube are, for example, 1.54, 1.33, and 1.0, respectively. Since the refractive index of the side wall of the infusion tube is larger than the refractive index of each of the other substances, a larger amount of the infrared ray is reflected at the boundary between the side wall of the infusion tube and each of the other substances.

FIG.2is an example of a captured image of the infusion tube captured by the detection device. The captured image illustrated inFIG.2is captured in a state in which the infusion tube extending in the vertical direction of the drawing is irradiated with an infrared ray from the left side in the horizontal direction of the drawing. In the present embodiment, in the captured image captured by the detection device, a portion where the intensity of the received infrared ray is high is bright, and conversely, a portion where the intensity of the received infrared ray is low is dark. Therefore, in the captured image, a region including both side walls of the infusion tube is displayed brightly in the extending direction of the captured infusion tube.

For example, the detection device can measure a light intensity value of each pixel included in the captured image by an image process such as an edge detection process, and can specify a high light intensity region R having a light intensity value equal to or more than a predetermined threshold as a region including both side walls of the infusion tube captured in the captured image based on a light intensity distribution in the captured image.

The detection device determines whether or not the infusion tube is blocked based on a light intensity distribution in the captured image. Specifically, when the infusion tube is blocked, the amount of liquid flowing in the infusion tube changes, and the thickness of the infusion tube changes. For example, when blockage occurs on a downstream side of a portion of the infusion tube captured in the captured image, the internal pressure of the portion increases, and the infusion tube captured in the captured image becomes thicker. Meanwhile, when the blockage occurs on an upstream side of the portion captured in the captured image of the infusion tube, the amount of liquid flowing in the portion decreases, and the internal pressure of the portion decreases. As a result, the infusion tube captured in the captured image becomes thinner.

Therefore, the detection device can determine whether or not the infusion tube is blocked based on the outer diameter D of the infusion tube captured in the captured image.

The detection device can further determine whether or not there are air bubbles in the infusion tube based on a light intensity distribution in the captured image. The captured image illustrated inFIG.2is captured in a state in which there is no air bubble in the infusion tube above a broken line and there are air bubbles in the infusion tube below the broken line. In the infusion tube, the light intensity distribution in the captured image is different between the portion where there are air bubbles inside and the portion where there is no air bubble inside due to a difference in refractive index between water and air. Specifically, as illustrated inFIG.1, in a case where there are air bubbles inside, the intensity of a reflected infrared ray increases when the infrared ray is incident on the inside of the infusion tube from the side wall of the infusion tube as compared with a case where there is no air bubble inside. Therefore, as illustrated inFIG.2, in the captured image, a region R1of the infusion tube including a side wall on an infrared ray light source side is brighter and a width W1thereof is thicker in the portion where there are air bubbles inside. Furthermore, in the portion where there are air bubbles inside, when the infrared ray is incident on the inside of the infusion tube from the side wall of the infusion tube, the intensity of the reflected infrared ray increases, and the intensity of transmitted infrared ray decreases. As described above, in the captured image, in the portion where there are air bubbles inside, a region R2of the infusion tube including a side wall on a side opposite to the light source is darker and a width W2thereof is thinner.

Therefore, the detection device can determine whether or not there are air bubbles in the infusion tube based on the width W (W1or W2) of at least one of the regions R1and R2each including a side wall of the infusion tube captured in the captured image.

In the present embodiment, a captured image captured by the detection device is described on the assumption that a region where the intensity of a received infrared ray is high is bright, and a region where the intensity of the received infrared ray is low is dark. Therefore, the detection device specifies a high light intensity region having a light intensity value equal to or more than a predetermined threshold in the captured image as a region including both side walls of the infusion tube captured in the captured image. However, in the captured image, a region where the intensity of the received infrared ray is high may be displayed darkly, and a region where the intensity of the received infrared ray is low may be displayed brightly. In such a case, the detection device may specify a low light intensity region having a light intensity value equal to or less than a predetermined threshold in the captured image as a region including both side walls of the infusion tube captured in the captured image.

Next, a configuration of a detection device1A, which is a first embodiment of the detection device according to the present disclosure, will be described in detail with reference toFIGS.3and4.FIG.3is a schematic diagram illustrating a schematic configuration of the detection device1A according to the first embodiment of the present disclosure.FIG.4is a perspective view of a first housing11of the detection device1A. InFIG.3, an infusion tube200attached to the detection device1A is indicated by a two-dot chain line. The detection device1A includes a receiving plate2, a contact portion3, an irradiation unit4, a light guide5, an imaging unit6, an output unit7, and a control unit8. In the present embodiment, as illustrated inFIG.3, the detection device1A includes the first housing11to which the infusion tube200is attached, and a second housing12facing the first housing11with the infusion tube200interposed therebetween. In the detection device1A, the receiving plate2, the contact portion3, and the light guide5are disposed in the first housing11, and the irradiation unit4, the imaging unit6, the output unit7, and the control unit8are disposed in the second housing12.

The receiving plate2is formed of a plate-like member. A surface of the receiving plate2abuts on the infusion tube200when the infusion tube200is attached to the detection device1A. In the present disclosure, as illustrated inFIG.3, a direction in which the infusion tube200attached to the detection device1A extends is referred to as an extending direction. A direction orthogonal to the extending direction on the surface of the receiving plate2is referred to as a width direction. A direction orthogonal to the extending direction and the width direction is referred to as a height direction. Furthermore, in the infusion tube200, a direction orthogonal to the extending direction is referred to as a radial direction. The radial direction of the infusion tube200includes the width direction and the height direction of the infusion tube200.

The contact portion3is configured to come into contact with the infusion tube200from both sides of the infusion tube200in the radial direction at two locations spaced apart from each other in the extending direction of the infusion tube200attached to the detection device1A. As illustrated inFIG.4, the contact portion3includes a first contact portion3A and a second contact portion3B. The first contact portion3A and the second contact portion3B protrude from the receiving plate2in the height direction at positions spaced apart from each other in the extending direction of the infusion tube200on the surface of the receiving plate2. Each of the first contact portion3A and the second contact portion3B includes two protrusions facing each other so as to come into contact with the infusion tube200from both sides of the infusion tube200in the width direction. As a result, in the infusion tube200attached to the detection device1A, the shape of the side wall is likely to change according to the amount of infusion flowing inside between the two locations in contact with the first contact portion3A and the second contact portion3B. Therefore, the detection device1A can more accurately detect abnormality of the infusion tube200by detecting abnormality between the two locations in contact with the first contact portion3A and the second contact portion3B of the infusion tube200. Hereinafter, a “section between the two locations in contact with the first contact portion3A and the second contact portion3B” of the infusion tube200is also referred to as a “target section” of the infusion tube200.

Referring again toFIG.3, the irradiation unit4is configured to emit an infrared ray toward the infusion tube200attached to the detection device1A. More specifically, the irradiation unit4is configured to emit an infrared ray toward the target section of the infusion tube200. The irradiation unit4includes one or more light sources. The light source is, for example, an infrared ray light emitting diode (LED). In the present embodiment, the irradiation unit4is disposed at a position of the second housing12where an incident surface51of the light guide5disposed in the first housing11can be irradiated with an infrared ray.

The light guide5is configured to guide an infrared ray emitted from the irradiation unit4to the infusion tube200attached to the detection device1A. The light guide5is, for example, an acrylic light guide member. In the present embodiment, the light guide5includes the incident surface51on which an infrared ray emitted from the irradiation unit4is incident and a reflecting surface52located on a side opposite to the incident surface51in the height direction. The reflecting surface52is an inclined surface having a predetermined inclination with respect to the height direction. In the present embodiment, the light guide5is disposed at a position sandwiched between the first contact portion3A and the second contact portion3B in the extending direction and facing the irradiation unit4in the height direction in the first housing11. As a result, as indicated by an arrow inFIG.3, an infrared ray emitted from the irradiation unit4in the height direction is incident on the incident surface51of the light guide5, is reflected by the reflecting surface52, travels in the width direction, and is emitted to the infusion tube200from the width direction of the infusion tube200attached to the detection device1A. In the present embodiment, an infrared ray emitted from the irradiation unit4is emitted to the target section of the infusion tube200attached to the detection device1A from the width direction of the infusion tube200via the light guide5.

By disposing the light guide5in the first housing11, the irradiation unit4can be disposed in the second housing12different from the first housing11to which the infusion tube200is attached. In the present embodiment, by disposing, in addition to the irradiation unit4, relatively expensive components such as the imaging unit6, the output unit7, and the control unit8in the second housing12, for example, when the infusion tube200is damaged, only the first housing11that can be contaminated with liquid in the infusion tube200can be replaced, and the second housing12can be continuously used.

The imaging unit6is configured to generate a captured image obtained by imaging the infusion tube200attached to the detection device1A. More specifically, the imaging unit6generates a captured image obtained by imaging the target section of the infusion tube200. The imaging unit6receives an infrared ray emitted from the irradiation unit4and reflected by the infusion tube200. As a result, the imaging unit6can generate a captured image obtained by imaging the infusion tube200irradiated with an infrared ray from the irradiation unit4. The imaging unit6includes an image sensor. The image sensor is, for example, a complementary metal oxide semiconductor (CMOS) image sensor, or a charge-coupled device (CCD) image sensor. In the present embodiment, the imaging unit6is disposed at a position of the second housing12facing the infusion tube200attached to the detection device1A in the height direction.

The output unit7is configured to output sound, vibration, light, an image, or the like. The output unit7includes, for example, an output device such as a speaker, a vibrator, a lamp, or a display.

The control unit8includes, for example, a memory81and a processor82.

The memory81is, for example, a semiconductor memory, a magnetic memory, or an optical memory. The memory81functions as, for example, a main storage device, an auxiliary storage device, or a cache memory. The memory81stores arbitrary information used for an operation of the detection device1A. For example, the memory81stores a system program, an application program, or embedded software.

The processor82may be, for example, a general-purpose processor such as a central processing unit (CPU) or a dedicated processor specialized for a specific process. The processor82may include, for example, a dedicated circuit such as a field-programmable gate array (FPGA) or an application specific integrated circuit (ASIC).

The control unit8is connected to each of the irradiation unit4, the imaging unit6, and the output unit7so as to be able to communicate therewith in a wired or wireless manner. As a result, the control unit8controls each unit such as the irradiation unit4, the imaging unit6, or the output unit7.

The control unit8detects blockage of the infusion tube200and air bubbles in the infusion tube200based on a light intensity distribution in a captured image. An operation of the detection device1A according to the present embodiment under control of the control unit8will be described with reference toFIGS.5and6.FIG.5is a flowchart illustrating an operation of blockage detection by the detection device1A.FIG.6is a flowchart illustrating an operation of air bubble detection by the detection device1A. These operations correspond to a detection method executed by the detection device1A. These operations will be described as being executed in a state in which the infusion tube200is attached to the detection device1A.

(Blockage Detection)

First, an operation of blockage detection by the detection device1A will be described with reference toFIG.5.

Step S101: The detection device1A images the infusion tube200.

Specifically, the control unit8causes the irradiation unit4to irradiate the infusion tube200with an infrared ray from the width direction of the infusion tube200attached to the detection device1A. The control unit8causes the imaging unit6to image the infusion tube200and generate a captured image in a state in which the infusion tube200is irradiated with the infrared ray. The control unit8may store the captured image generated by the imaging unit6.

Step S102: The detection device1A measures the outer diameter D of the infusion tube200captured in the captured image at least at one point of the infusion tube200captured in the captured image in the extending direction based on a light intensity distribution.

Specifically, the control unit8specifies a high light intensity region R (seeFIG.2) having a light intensity value equal to or more than a predetermined threshold in the captured image by an edge detection process. The high light intensity region R includes a first region R1and a second region R2distributed in the extending direction of the infusion tube200captured in the captured image. The first region R1is a region including one of the two side walls of the infusion tube200captured in the captured image. The second region R2is a region including a side wall different from the first region R1out of the two side walls of the infusion tube200captured in the captured image. In the present embodiment, the control unit8measures a distance between the farthest ends of the first region R1and the second region R2at a certain point of the infusion tube200in the extending direction captured in the captured image. The control unit8stores the measured distance between the farthest ends of the first region R1and the second region R2as the outer diameter D of the infusion tube200. However, the control unit8may measure a distance between the farthest ends of the first region R1and the second region R2at a plurality of points of the infusion tube200in the extending direction captured in the captured image. In such a case, the control unit8may define an average value, a maximum value, a minimum value, or the like of the outer diameter of the infusion tube200at each of the plurality of points of the infusion tube200in the extending direction captured in the captured image as the outer diameter D of the infusion tube200. Furthermore, the control unit8stores the outer diameter D of the infusion tube200measured by first executing step S102as an initial value Do.

Step S103: The detection device1A determines whether or not the infusion tube200is blocked based on the measured outer diameter D of the infusion tube200.

Specifically, the control unit8determines whether or not the measured outer diameter D of the infusion tube200and its initial value D0satisfy the following formula (1).
DA<D−D0<DBFormula (1)

Here, DAand DBare thresholds for blockage detection. DAand DBare an upper limit value and a lower limit value of a displacement of the measured outer diameter D of the infusion tube200from the initial value D0, respectively. In the present embodiment, DAis a negative constant, and DBis a positive constant.

When the measured outer diameter D of the infusion tube200satisfies formula (1), that is, when a displacement of the outer diameter D from the initial value D0is within a predetermined range, the control unit8determines that the infusion tube200is not blocked. When the control unit8determines that the infusion tube200is not blocked (step S103—No), the control unit8continues the process from step S101.

When the measured outer diameter D of the infusion tube200does not satisfy formula (1), that is, when a displacement of the outer diameter D from the initial value D0is not within a predetermined range, the control unit8determines that the infusion tube200is blocked. When the control unit8determines that the infusion tube200is blocked (step S103—Yes), the control unit8executes a process of step S104.

Step S104: The detection device1A outputs that blockage of the infusion tube200has been detected.

Specifically, the control unit8causes the output unit7to output that blockage of the infusion tube200has been detected, and ends the present process. For example, the control unit8may cause a display included in the output unit7to display “blockage detection”.

The control unit8may further change the output content to be output by the output unit7according to a detected state of blockage of the infusion tube200.

For example, when DAD−D0is satisfied, the control unit8determines that the outer diameter D of the infusion tube200captured in the captured image is narrower than the initial value D0by a predetermined amount or more. This is considered to be because the amount of liquid flowing through the infusion tube200captured in the captured image has decreased due to occurrence of blockage on an upstream side of the infusion tube200captured in the captured image. In such a case, the control unit8may cause the output unit7to output that blockage has occurred on the upstream side of the infusion tube200captured in the captured image.

For example, when DBD−D0is satisfied, the control unit8determines that the outer diameter D of the infusion tube200captured in the captured image is wider than the initial value D0by a predetermined amount or more. This is considered to be because the amount of liquid flowing through the infusion tube200captured in the captured image has increased due to occurrence of blockage on a downstream side of the infusion tube200captured in the captured image. In such a case, the control unit8may cause the output unit7to output that blockage has occurred on the downstream side of the infusion tube200captured in the captured image.

(Air Bubble Detection)

Next, an operation of air bubble detection by the detection device1A will be described with reference toFIG.6. In the present embodiment, an example will be described in which the detection device1A measures both the widths W1and W2of the region including the side wall of the infusion tube200captured in the captured image to perform air bubble detection. However, the detection device1A may measure one of the widths W1and W2to perform air bubble detection. In such a case, in the description of subsequent steps, a process for the other width W1or W2that has not been measured is not performed.

Step S201: The detection device1A images the infusion tube200as described in step S101.

Specifically, the control unit8causes the irradiation unit4to irradiate the infusion tube200with an infrared ray from the width direction of the infusion tube200attached to the detection device1A. The control unit8causes the imaging unit6to image the infusion tube200and generate a captured image in a state in which the infusion tube200is irradiated with the infrared ray. The control unit8may store the captured image generated by the imaging unit6.

Step S202: The detection device1A measures the width W of the region including the side wall of the infusion tube200captured in the captured image at least at one point of the infusion tube200in the extending direction captured in the captured image based on a light intensity distribution.

Specifically, the control unit8specifies a high light intensity region R having a light intensity value equal to or more than a predetermined threshold in the captured image by an edge detection process. As described above, the high light intensity region R includes the first region R1and the second region R2including the two side walls of the infusion tube200, respectively. In the present embodiment, the control unit8measures the width W1of the first region R1and the width W2of the second region R2at a certain point of the infusion tube200in the extending direction captured in the captured image. However, the control unit8may measure the widths of the first region R1and the second region R2at a plurality of points of the infusion tube200in the extending direction captured in the captured image. In such a case, the control unit8may define average values, maximum values, minimum values, or the like of the widths of the first region R1and the second region R2at the plurality of points of the infusion tube200in the extending direction captured in the captured image as the width W1of the first region R1and the width W2of the second region R2, respectively. Furthermore, the control unit8stores the width W1of the first region R1and the width W2of the second region R2measured by first executing step S202as initial values W10and W20, respectively.

Step S203: The detection device1A determines whether or not air bubbles are generated in the infusion tube200based on the measured width W of the region including the side wall of the infusion tube200.

Specifically, the control unit8determines whether or not the measured width W1of the first region R1and its initial value W10satisfy the following formula (2).
W1−W10<W1AFormula (2)

Here, W1Ais a threshold for air bubble detection. W1Ais an upper limit value of a displacement of the measured width W of the first region R1of the infusion tube200from the initial value W10. In the present embodiment, W1Ais a positive constant.

The control unit8further determines whether or not the measured width W2of the second region R2and its initial value W20satisfy the following formula (3).
W2−W20<W2AFormula (3)

Here, W2Ais a threshold for air bubble detection. W2Ais a lower limit value of a displacement of the measured width W of the second region R2of the infusion tube200from the initial value W20. W2Ais a negative constant.

When the measured width W1of the first region R1satisfies formula (2) and the measured width W2of the second region R2satisfies formula (3), that is, when displacements of the widths W1and W2from the initial values W10and W20are within the predetermined ranges, respectively, the control unit8determines that there is no air bubble in the infusion tube200. When the control unit8determines that there is no air bubble in the infusion tube200(step S203-No), the control unit8continues the process from step S201.

When the measured width W1of the first region R1does not satisfy formula (2) or the measured width W2of the second region R2does not satisfy formula (3), that is, when at least one of displacements of the widths W1and W2from the initial values W10and W20, respectively, is not within the predetermined range, the control unit8determines that there are air bubbles in the infusion tube200. When the control unit8determines that there are air bubbles in the infusion tube200(step S203—Yes), the control unit8executes a process of step S204.

Step S204: The detection device1A outputs that air bubbles in the infusion tube200have been detected.

Specifically, the control unit8causes the output unit7to output that air bubbles in the infusion tube200have been detected, and ends the present process. For example, the control unit8may cause a display included in the output unit7to display “air bubble detection”.

In the present disclosure, the process of detecting blockage of the infusion tube200and the process of detecting air bubbles in the infusion tube200have been individually described, but these processes may be performed in parallel. Specifically, the control unit8performs the process of detecting blockage of the infusion tube200and the process of detecting air bubbles in the infusion tube200on one captured image captured by the imaging unit6. When blockage of the infusion tube200is not detected and no air bubble in the infusion tube200is detected, the control unit8continues these processes. When blockage of the infusion tube200is detected or when air bubbles in the infusion tube200are detected, the control unit8may cause the output unit7to output the fact and end these processes.

(Second Embodiment of Detection Device)

A detection device1B, which is a second embodiment of the detection device according to the present disclosure, will be described with reference toFIG.7.FIG.7is a schematic diagram illustrating a schematic configuration of the detection device1B according to the second embodiment.

The detection device1B is different from the detection device1A described above in the first embodiment in that an irradiation unit4of the detection device1B includes two light sources (for example, a first light source4A and a second light source4B) in the second embodiment. Furthermore, the detection device1B is different from the detection device1A in including two light guides5. Hereinafter, the second embodiment will be described focusing on differences from the first embodiment. Note that portions having the same configurations as those of the first embodiment are denoted by the same reference characters.

As illustrated inFIG.7, the detection device1B includes a receiving plate2, a contact portion3, the irradiation unit4, the light guide5, an imaging unit6, an output unit7, and a control unit8.

In the detection device1B, the irradiation unit4includes the first light source4A and the second light source4B that emit infrared rays from directions facing each other in a radial direction of an infusion tube200attached to the detection device1B toward the infusion tube200. In the present embodiment, the first light source4A and the second light source4B of the irradiation unit4are disposed at positions of a second housing12where incident surfaces51of the two light guides5A and5B disposed in a first housing11can be irradiated with infrared rays, respectively.

The two light guides5A and5B may each have the same shape as the light guide5of the detection device1A described above in the first embodiment. In the detection device1B, the light guide5A is disposed at the same position as the light guide5described above in the detection device1A in the first housing11. The light guide5B is disposed at a position facing the light guide5A with the infusion tube200attached to the detection device1B interposed therebetween in the first housing11. As a result, as indicated by an arrow inFIG.7, an infrared ray emitted from the first light source4A of the irradiation unit4in the height direction is emitted to the infusion tube200from the width direction of the infusion tube200via the light guide5A. Furthermore, an infrared ray emitted from the second light source4B of the irradiation unit4in the height direction is emitted to the infusion tube200from a direction facing the infrared ray emitted from the first light source4A in the width direction of the infusion tube200via the light guide5B.

The control unit8of the detection device1B causes the irradiation unit4to emit infrared rays from both the first light source4A and the second light source4B. The control unit8of the detection device1B causes the imaging unit6to capture a captured image obtained by imaging the infusion tube200in a state in which infrared rays are emitted from both the first light source4A and the second light source4B. The control unit8of the detection device1B performs a process of detecting blockage of the infusion tube200and a process of detecting air bubbles in the infusion tube200in a similar manner to the method described above in the detection device1A based on the captured image. When blockage of the infusion tube200or air bubbles in the infusion tube200are detected based on the captured image, the control unit8of the detection device1B causes the output unit7to output the fact.

With such a configuration, the detection device1B can irradiate the infusion tube200with infrared rays from two directions facing each other to more clearly image the infusion tube200as compared with a case where the infusion tube200is irradiated with an infrared ray from one direction. As a result, the detection device1B can more accurately detect abnormality of the infusion tube200.

(Third Embodiment of Detection Device)

A detection device1C, which is a third embodiment of the detection device according to the present disclosure, will be described with reference toFIG.8.FIG.8is a schematic diagram illustrating a schematic configuration of the detection device1C according to the third embodiment.

The detection device1C is different from the detection device1A described above in the first embodiment in that an irradiation unit4of the detection device1C includes a plurality of light sources (for example, two light sources4C and4D) in the third embodiment. Hereinafter, the third embodiment will be described focusing on differences from the first embodiment. Note that portions having the same configurations as those of the first embodiment are denoted by the same reference characters.

As illustrated inFIG.8, the detection device1C includes a receiving plate2, a contact portion3, the irradiation unit4, a light guide5, an imaging unit6, an output unit7, and a control unit8.

In the detection device1C, the irradiation unit4includes the plurality of light sources4C and4D that emits infrared rays toward an infusion tube200from different directions. The present embodiment will be described on the assumption that the number of the plurality of light sources is two, but the number of the plurality of light sources may be three or more. In the present embodiment, the light source4C of the irradiation unit4is disposed at the same position of the second housing12as the light source of the irradiation unit4described above in the detection device1A. That is, the light source4C is disposed at the position of the second housing12where the infusion tube200can be irradiated with an infrared ray from the width direction of the infusion tube200via the light guide5disposed in a first housing11. Meanwhile, the light source4D is disposed at a position of the second housing12where the infusion tube200attached to the detection device1C can be directly irradiated with an infrared ray. That is, the light source4D is disposed at the position of the second housing12where the infusion tube200can be irradiated with an infrared ray from a direction different from the light source4C. As a result, as indicated by an arrow inFIG.8, in the detection device1C, the light source4C of the irradiation unit4can irradiate the infusion tube200with an infrared ray from the width direction of the infusion tube200. In addition, in the detection device1C, the light source4D of the irradiation unit4can irradiate the infusion tube200with an infrared ray from a direction different from the light source4C.

The control unit8of the detection device1C causes the irradiation unit4to emit infrared rays alternately from the plurality of light sources4C and4D. The control unit8of the detection device1C causes the imaging unit6to capture a first captured image obtained by imaging the infusion tube200in a state in which an infrared ray is emitted from the light source4C. The control unit8of the detection device1C causes the imaging unit6to capture a second captured image obtained by imaging the infusion tube200, for example, in a state in which an infrared ray is emitted from the light source4D. The control unit8of the detection device1C performs a process of detecting blockage of the infusion tube200and a process of detecting air bubbles in the infusion tube200in a similar manner to the method described above in the detection device1A based on each of the first captured image and the second captured image. When blockage of the infusion tube200or air bubbles in the infusion tube200are detected based on at least one of the first captured image and the second captured image, the control unit8of the detection device1C causes the output unit7to output the fact.

With such a configuration, the detection device1C can irradiate the infusion tube200with infrared rays from various directions to image the infusion tube200. As a result, the detection device1C can more accurately detect abnormality of the infusion tube200.

(Fourth Embodiment of Detection Device)

A detection device1D, which is a fourth embodiment of the detection device according to the present disclosure, will be described with reference toFIG.9.FIG.9is a schematic diagram illustrating a schematic configuration of the detection device1D according to the fourth embodiment.

The detection device1D is different from the detection device1A described above in the first embodiment in that an infrared ray emitted from an irradiation unit4of the detection device1D is emitted to an infusion tube200from a lower portion of the infusion tube200in the height direction toward an imaging unit6in the fourth embodiment. Hereinafter, the fourth embodiment will be described focusing on differences from the first embodiment. Note that portions having the same configurations as those of the first embodiment are denoted by the same reference characters.

As illustrated inFIG.9, the detection device1D includes a receiving plate2, a contact portion3, the irradiation unit4, a light guide5, the imaging unit6, an output unit7, and a control unit8.

In the detection device1D, the light guide5has an incident surface51on which an infrared ray emitted from the irradiation unit4is incident, a first reflecting surface52A located on a side opposite to the incident surface51in the height direction, and a second reflecting surface52B disposed in the width direction with respect to the first reflecting surface52A and disposed so as to be located at a lower portion of the infusion tube200in the height direction. The first reflecting surface52A and the second reflecting surface52B are each an inclined surface having a predetermined inclination with respect to the height direction. As a result, as indicated by a solid arrow inFIG.9, an infrared ray emitted in the height direction from the irradiation unit4is incident on the incident surface51of the light guide5, is reflected by the first reflecting surface52A, travels in the width direction, is reflected by the second reflecting surface52B, travels in the height direction, and is emitted to the infusion tube200from a lower portion of the infusion tube200attached to the detection device1D in the height direction toward the imaging unit6. As a result, the imaging unit6can image transmitted light (broken line arrow) of an infrared ray emitted from a side facing the imaging unit6via the infusion tube200.

The control unit8can evaluate a change in the outer diameter D of the infusion tube200in the captured image generated by the imaging unit6to determine whether or not the infusion tube200is blocked. Furthermore, the control unit8can evaluate a change in a light intensity distribution of transmitted light in the captured image generated by the imaging unit6to determine whether or not air bubbles are generated in the infusion tube200. Specifically, the control unit8can determine whether or not air bubbles are generated in the infusion tube200from a difference in intensity of transmitted light reaching the imaging unit6between a case where the infusion tube200is filled with liquid and a case where the infusion tube200includes air bubbles. Therefore, even when air bubbles are generated in a part of a cross section of the infusion tube200, the air bubbles can be more accurately detected with transmitted light passing through the infusion tube200and reaching the imaging unit6.

(Infusion Pump)

A configuration of an infusion pump100according to an embodiment of the present disclosure will be described in detail with reference toFIGS.10and11. Hereinafter, when the detection devices1A,1B,1C, and1D described above are not particularly distinguished from each other, they are simply collectively referred to as a detection device1.FIG.10is a front view illustrating a schematic configuration of the infusion pump100according to the embodiment of the present disclosure. The infusion pump100includes the detection device1according to the present disclosure. As illustrated inFIG.10, the infusion pump100may include a pump body110and an infusion cartridge120detachable from the pump body110. As a result, in the infusion pump100, the pump body110can be reused by replacing the disposable infusion cartridge120. The infusion pump100can be used, for example, as a PCA pump, but an application thereof is not particularly limited.

As illustrated inFIG.10, a display unit111on which various types of information are displayed and an operation unit112in which operation switches and the like are arranged are disposed on a front surface of the pump body110. For example, a liquid feeding rate, an integrated dose, and the like are displayed on the display unit111. Furthermore, information indicating that blockage of the infusion tube200or air bubbles in the infusion tube200have been detected by the detection device1is displayed on the display unit111. The display unit111may be a liquid crystal screen with a touch panel used for setting a liquid feeding rate and the like. The operation unit112includes one or more operation switches. The operation switches disposed in the operation unit112are, for example, a fast delivery switch that makes liquid feeding at a liquid feeding rate higher than a set liquid feeding rate (mL/h) possible while being pressed, a start switch that starts liquid feeding by being pressed, a stop switch that forcibly stops liquid feeding by being pressed, and a power supply switch for instructing ON/OFF of power supply of the pump body110.

FIG.11is a perspective view of the infusion cartridge120of the infusion pump100. The infusion cartridge120includes a case122for storing an infusion pack filled with an infusion therein.

On a side of the case122facing the pump body110when being attached to the pump body110, the infusion tube200, a tube receiving portion121that receives the infusion tube200and sandwiches the infusion tube200between the tube receiving portion121and the pump body110, and a filling port123connected to an infusion pack stored in the case122are formed. The tube receiving portion121according to the present embodiment includes a groove into which the infusion tube200is fitted. To the filling port123, the infusion pack is connected from the inside of the case122, and the infusion tube200is connected from the outside of the case122. As a result, the infusion in the infusion pack stored in the case122can be fed to the outside via the infusion tube200.

Referring again toFIG.10, the pump body110includes a liquid feeding unit113that sandwiches the infusion tube200of the infusion cartridge120with the tube receiving portion121of the infusion cartridge120to be attached and feeds the infusion in the infusion tube200from an upstream side of the infusion tube200to a downstream side of the infusion tube200. The liquid feeding unit113includes a plurality of fingers and a drive portion that drives the fingers. The plurality of fingers is disposed on a side surface of the pump body110facing the tube receiving portion121located on a side surface of the infusion cartridge120. The plurality of fingers are arranged in the extending direction of the infusion tube200. Each of the fingers is driven by the drive portion so as to reciprocate in a direction facing the tube receiving portion121of the infusion cartridge120. Each of the fingers moves so as to approach the infusion cartridge120, and the infusion tube200is thereby sandwiched between each of the fingers and the tube receiving portion121. As a result, the infusion tube200is closed under pressure. The drive portion sequentially drives the fingers from the upstream side of the infusion tube200toward the downstream side of the infusion tube200in the extending direction of the infusion tube200. As a result, the infusion tube200is sequentially closed under pressure from the upstream side of the infusion tube200toward the downstream side of the infusion tube200, and peristaltically moves. Therefore, the infusion pump100can feed the infusion in the infusion tube200from the upstream side of the infusion tube200toward the downstream side of the infusion tube200.

The infusion cartridge120includes the first housing11of the detection device1. The pump body110includes the second housing12of the detection device1at a position facing the first housing11disposed in the infusion cartridge120. In the present embodiment, the second housing12is disposed at a position on the downstream side of the infusion tube200with respect to the liquid feeding unit113, but may be disposed on the upstream side of the infusion tube200with respect to the liquid feeding unit113.

The pump body110and the infusion cartridge120are not limited to the configurations of the present embodiment. The pump body110and the infusion cartridge120may each include, for example, portions different from the above-described portions. In addition, as described above, the liquid feeding unit113of the pump body110in the present embodiment has a configuration in which the infusion tube200is pressed by the plurality of fingers. However, the liquid feeding unit113may have a different configuration as long as the infusion in the infusion tube200can be fed.

As described above, the detection device1according to the present disclosure includes: the irradiation unit4that emits an infrared ray toward the infusion tube200; the imaging unit6configured to generate a captured image obtained by imaging the infusion tube200irradiated with the infrared ray by the irradiation unit4; and the control unit8that detects blockage of the infusion tube200and air bubbles in the infusion tube200based on a light intensity distribution in the captured image. According to such a configuration, the detection device1can detect blockage of the infusion tube200and air bubbles in the infusion tube200by a single mechanism. Therefore, the detection device1can improve a technique for detecting abnormality of the infusion tube200.

In the detection device1as an embodiment, the control unit8can detect blockage of the infusion tube200based on the outer diameter of the infusion tube200captured in the captured image. According to such a configuration, the detection device1can easily detect blockage of the infusion tube200based on the captured image of the infusion tube200captured by emitting an infrared ray.

In the detection device1as an embodiment, the control unit8can detect air bubbles in the infusion tube200based on the width of the region including the side wall of the infusion tube200captured in the captured image. According to such a configuration, the detection device1can easily detect air bubbles in the infusion tube200based on the captured image of the infusion tube200captured by emitting an infrared ray.

In the detection device1as an embodiment, the irradiation unit4includes the first light source4A and the second light source4B that emit infrared rays toward the infusion tube200from directions facing each other in a radial direction of the infusion tube200, and the control unit8can detect blockage of the infusion tube200and air bubbles in the infusion tube200based on a captured image obtained by imaging the infusion tube200in a state in which the infrared rays are emitted from both the first light source4A and the second light source4B. According to such a configuration, the detection device1can irradiate the infusion tube200with infrared rays from two directions facing each other to more clearly image the infusion tube200as compared with a case where the infusion tube200is irradiated with an infrared ray from one direction. As a result, the detection device1can more accurately detect abnormality of the infusion tube200.

In the detection device1as an embodiment, the irradiation unit4includes a plurality of light sources that emits infrared rays toward the infusion tube200from different directions, and the control unit8can detect blockage of the infusion tube200and air bubbles in the infusion tube200based on a plurality of captured images obtained by imaging the infusion tube200in a state in which the infrared rays are emitted from different light sources. According to such a configuration, the detection device1can irradiate the infusion tube200with infrared rays from various directions to image the infusion tube200. As a result, the detection device1can more accurately detect abnormality of the infusion tube200.

The detection device1as an embodiment further includes the contact portion3that comes into contact with the infusion tube200from both sides of the infusion tube200in the radial direction at two locations spaced apart from each other in the extending direction of the infusion tube200, and the control unit8can detect blockage of the infusion tube200and air bubbles in the infusion tube200based on a light intensity distribution between the two locations in the extending direction of the infusion tube200captured in the captured image. According to such a configuration, the detection device1can easily change the shape of the infusion tube200between the two locations in contact with the contact portion3of the infusion tube200in the extending direction. Therefore, the detection device1can more accurately detect abnormality.

The infusion pump100according to the present disclosure includes the detection device1described above. According to such a configuration, the infusion pump100can detect blockage of the infusion tube200and air bubbles in the infusion tube200by a single mechanism. Therefore, the infusion pump100can improve a technique for detecting abnormality of the infusion tube200.

Although the present disclosure has been described with reference to the drawings and examples, it should be noted that those skilled in the art can make various variations and modifications based on the present disclosure. Therefore, it should be noted that these variations and modifications fall within the scope of the present disclosure. For example, functions and the like included in each means, each step, or the like can be rearranged so as not to be logically inconsistent, and a plurality of means, steps, and the like can be combined into one or divided.

For example, in the above-described embodiments, the detection device1has been described as including the first housing11and the second housing12, in which the receiving plate2, the contact portion3, and the light guide5are disposed in the first housing11, and the irradiation unit4, the imaging unit6, the output unit7, and the control unit8are disposed in the second housing12. However, in the detection device1, all of the above-described components may be disposed in one housing. This makes it possible to manufacture the detection device1by a simpler manufacturing method, and to suppress manufacturing cost. Alternatively, at least one of the components described as being disposed in the first housing11or the second housing12may be disposed in the other housing.

Alternatively, in the above-described embodiments, the detection device1has been described as including the light guide5. However, when the irradiation unit4is disposed at a position where the irradiation unit4can directly irradiate the infusion tube200attached to the detection device1with an infrared ray, the light guide5may be omitted. This makes it possible to manufacture the detection device1by a simpler manufacturing method, and to suppress manufacturing cost.

Alternatively, in the above-described embodiments, the detection device1has been described as including the receiving plate2, the contact portion3, the irradiation unit4, the light guide5, the imaging unit6, the output unit7, and the control unit8. However, at least one of these components may be provided by the infusion pump100on which the detection device1is mounted. That is, the detection device1according to the present disclosure may be the infusion pump100itself. For example, the control unit8of the detection device1may be a control device included in the infusion pump100. Specifically, a program describing processing contents executed by the control unit8of the detection device1according to an embodiment can be stored in a memory of the control device of the infusion pump100, and the program can be read and executed by a processor of the control device of the infusion pump100. Alternatively, the output unit7of the detection device1may be the display unit111included in the infusion pump100.

Alternatively, in the above-described embodiments, the thresholds DAand DBfor blockage detection and the thresholds W1Aand W2Afor air bubble detection have been described as being constants. However, these values may be variables that can vary depending on the temperature of an environment in which the detection device1is used. In such a case, the control unit8of the detection device1may store a correspondence relationship between the temperature of the environment and thresholds of blockage detection and air bubble detection, and set the above-described thresholds when performing abnormality detection. As a result, the detection device1can more accurately detect abnormality of the infusion tube200in consideration of factors that vary depending on the temperature of the environment, such as an expansion ratio of the infusion tube200.

REFERENCE CHARACTER LIST

1(1A,1B,1C,1D) Detection device11First housing12Second housing2Receiving plate3Contact portion3A First contact portion3B Second contact portion4(4A,4B,4C,4D) Irradiation unit (light source)5(5A,5B) Light guide51Incident surface52(52A,52B) Reflecting surface6Imaging unit7Output unit8Control unit81Memory82Processor100Infusion pump110Pump body111Display unit112Operation unit113Liquid feeding unit120Infusion cartridge121Tube receiving portion122Case123Filling port200Infusion tubeR (R1, R2) High light intensity regionD (D0) Outer diameterDA, DBThreshold of blockage detectionW (W1, W2, W10, W20) WidthW1A, W2AThreshold of air bubble detection