JPH0636823B2 - Infusion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infusion device for injecting various medicinal solutions, blood and the like into a patient by using a syringe pump.

[0002]

2. Description of the Related Art An infusion device which operates a sucker to attach a syringe containing a drug solution or the like to a syringe mounting portion and presses the sucker with a slider that linearly moves by rotation of a motor to perform an infusion operation is, for example, JP-A-48-62289, JP-A-57-76637, JP-B-62-44
No. 505 and Japanese Patent Publication No. 63-44390.

In the conventional infusion device, the infusion operation (movement of the slider) is monitored via a rotary encoder attached to the motor shaft of the motor or a linear potentiometer attached to the slider.

[0004]

When the infusion operation is monitored by using the rotary encoder, the motion conversion mechanism between the motor and the slider is damaged or slips.
If the motor and rotary encoder run idle, monitoring of the infusion operation will be impossible or inaccurate.

Further, when the above linear potentiometer is used, it has a drawback that it is easily affected by noise from the outside, and that the mechanical contact portion of the brush of the linear potentiometer is easily worn and the service life is short. .

In view of the above points, the present invention provides an infusion device capable of accurately monitoring the infusion operation and causing no problem in its life.

[0007]

The infusion device according to the present invention comprises a syringe in which a liquid is stored, and a moving member which is linearly moved at a predetermined speed between a first position and a second position by a drive mechanism. A pickup having a slider for pressing the sucker of the syringe in conjunction with the moving member, and a light emitting element and a light receiving element mounted on the moving member and moving between the first and second positions; Reflection provided between the third and fourth positions corresponding to the first and second positions, respectively, so that the light from the light emitting device is reflected by the light receiving device and its optical path length corresponds to the position of the pickup. An encoder including a plate, and a detection unit that detects the position of the sucker based on an electric signal output from the pickup according to an optical path length corresponding to the position of the pickup, respectively. That.

The reflecting surface of the reflecting plate is formed into a flat surface, and the reflecting surface is extended between the third and fourth positions at a predetermined angle with respect to the moving direction of the pickup and extends between the third and fourth positions. The optical path length may be increased or decreased depending on the position.

The detecting means includes an A / D converter to which the analog signal from the pickup is input, and a digital signal output from the A / D converter and a plurality of boundary values set to predetermined values. The position and the like of the sucker may be detected by comparing the above.

Further, the detecting means selectively outputs a preamplifier for adjusting the offset and span of the analog signal from the pickup and outputting the analog signal, and a second analog signal adjusted by the preamplifier within a predetermined voltage range. A multiplexer, an A / D converter to which the second analog signal is input, and a processor in which a plurality of boundary values for setting a digital signal output from the A / D converter are set are provided respectively. You may comprise so that the position etc. of the said sucker may be detected.

[0011]

Embodiments of the infusion device according to the present invention will be described below with reference to the drawings.

The infusion device 1 shown in FIG. 1 includes a mounting portion 5 for mounting the syringe 3 on the upper surface of the case 2 and the syringe 3.
And an operation unit 4 for monitoring the infusion operation and the infusion state.

The syringe 3 has a total capacity of 10 depending on the application.
Standard products such as ml, 30 ml, and 50 ml are used. Since the standards such as the diameter and the length with respect to the volume of the syringe 3 are different for each manufacturer, the infusion device 1 is adjusted so as to correspond to each manufacturer of the syringe 3 to be used.

Further, on the operation section 4, a volume indicator 6 for displaying the volume of the syringe 3 mounted, a centralized indicator 7 for displaying various operating states, an infusion start indicator 8, and an infusion stop. A display unit 9 and a 4-digit numerical display unit 10 for displaying the flow rate during infusion and the cumulative flow rate in ml / hour or ml are arranged.

The centralized indicator 7 is provided with various indicators indicating the operating state of the infusion device. Further, the operation unit 4 has a one-shot button 11 capable of sending a larger amount of liquid medicine than an ordinary liquid supply in an emergency, an infusion amount button 12 for selecting the display content of the numerical display 10, an infusion start / stop button 13, Fast-forward button 14, learning function setting button 1
7 and the power button 15 are arranged. Furthermore, above and below the numerical display 10, flow rate setting buttons 16 for setting the flow rate for each digit are arranged.

Next, a syringe 3 is attached to the pump mounting portion 5.
An outer cylinder 21 is mounted on the mounting portion 22, and a holding portion 26 that presses and fixes the syringe 3 from above is pressed, and a sucker 23 that slidably moves in the syringe 3 is pressed to push the sucker 23. A slider 24 for moving 23 in the direction of arrow a is further provided. The slider 24 is movably supported by a part of a drive mechanism 25 covered with a bellows 29. A syringe diameter detector (not shown) is provided below the holder 26.

Therefore, the outer cylinder 21 of the syringe 3 is held between the mounting portion 22 and the holding portion 26, and the rear end portion of the sucker 23 contacts the slider 24. A flexible infusion pipe (not shown) communicating with the injection needle is connected to the tip of the syringe 3. Therefore, when the syringe 3 is mounted on the mounting portion 22 and the slider 24 presses the sucker 23 in the direction of arrow a at a predetermined speed by the driving means, the drug solution in the syringe 3 is pushed out at a predetermined flow rate, and the infusion pipe. And injected into the patient via a needle.

The learning function setting button 17 will be described later with information about the syringe to be newly placed when changing the setting of the syringe to be placed on the infusion device 1 or adding the type of syringe. Used when inputting to the processor.

FIG. 2 is a sectional view showing a main part of the infusion device 1 according to the present invention. As shown in FIG. 2, the drive mechanism 25 of the sucker 23 includes a main shaft 30 and a release shaft (not shown) slidably supported by the frame 5a of the mounting portion 5. This spindle 3
0 has one end fixed to the slider 24 and the other end the moving member 3
Fixed to 2. On the other hand, the release shaft is arranged on the opposite side of the main shaft 30 and is not shown, but one end thereof is pivotally supported by the slider 24 and the other end thereof is pivotally supported by the moving member 32.
One end is fixed to the release button 28 via an arm, and the other end is fixed to an engaging claw (not shown) of the moving member 32.

Similar to the slider 24, the moving member 32 is slidably supported within the frame 5a of the mounting portion 5 and is reciprocated by the feed screw 34 which can be engaged with the engaging claw. That is, each of the moving members 32 is a guide rod (which is arranged in front of the feed screw 34, but not shown) arranged in parallel with the main shaft 30 and the release shaft within the frame 5a of the mounting portion 5.
Also, it is slidably attached to the feed screw 34. The feed screw 34 is axially supported by the frame 5a of the mounting portion 5 and is supported so as to be slightly movable in the axial direction. One end 34a abuts the pressure sensor 40, and the large gear 41 is fixed to the other end. The large gear 41 meshes with a small gear fixed to the rotating shaft of a motor (not shown).

Next, the encoder 27 for detecting the position of the sucker 23 is, as shown in FIG. 2, a pickup 35 attached to the lower end of the moving member 32 and its reflecting surface 33a.
, And a reflector 33 arranged so as to face the pickup 35. The pickup 35 includes a light emitting element 36 and a light receiving element 37.

As shown in FIG. 2, the pickup 35
Is a moving member 32 that is moved by the rotation of the feed screw 34.
Move with. As shown in FIG. 3, the pickup 35 moves between a second position at the left end shown by a two-dot chain line and a first position shown by a one-dot chain line. The first and second positions of the pickup 35 are wider than the moving range of the sucker 23.

Next, the reflecting plate 33 is located at the first and second positions, which are the moving range of the pickup 35, and at the third position corresponding to the first position, which is the position where the light from the light emitting element 36 can be reflected. And between the second position and the corresponding fourth position.

The reflecting plate 33 has a reflecting surface 33.
The distance between a and the pickup 35 is configured to change in the moving range of the pickup 35. In the embodiment, as shown in FIGS. 2 and 3, the flat reflecting plate 33 is arranged at the third and fourth positions while being inclined at a predetermined angle with respect to the moving direction of the pickup 35. With this configuration, as shown in FIG. 3, when the pickup 35 is at the first position, the distance between the reflection plate 33 and the pickup 35 is minimized, and the distance is gradually increased as the pickup 35 moves to the second position. The distance becomes maximum when the pickup 35 is in the second position.

That is, the light from the light emitting element 36 is reflected by the reflector 3
The optical path length after reaching the light receiving element 37 after being reflected by 3 changes depending on the position occupied by the pickup 35.

Next, the detecting means 38 for detecting the position of the sucker 23 will be described with reference to FIG. First, the light emitting element 36 emits a constant amount of light so that the constant voltage power source 39
Predetermined electric power is supplied from (hereinafter referred to as power supply 39).
Then, the light emitted from the light emitting element 36 is reflected by the reflecting plate 33 shown in FIGS. 2 and 3, and is received by the light receiving element 37. The light receiving element 37 is supplied with a current from a power source 39 via a resistor R (which may be a constant current element or a circuit) and outputs an analog signal (voltage) corresponding to the intensity of the received light.

The light emitting element 36 always emits a constant amount of light, and the amount of light received by the light receiving element 37 increases or decreases according to the change in the optical path length.

In the embodiment shown in FIG. 4, when the amount of light received by the light receiving element 37 decreases, the voltage of the analog signal output from the light receiving element 37 increases, and when the amount of light received increases, the voltage of the analog signal output. Decreases.

Next, the analog signal from the light receiving element 37 is input to the preamplifier 42 via the resistor R2. Note that this analog signal has a resistance R3 and +
Offset adjustment is performed by the variable resistor R4 to which Vcc and −Vcc are applied, and span adjustment is performed by the variable resistor R1 to form a second analog signal within a predetermined voltage width, which is input to the multiplexer 43.

The second analog signal selectively output from the multiplexer 43 is input to the A / D converter 44, converted into a digital signal, and then supplied to the processor 45. This processor 45 has a map 46 in which a plurality of boundary values are preset for the position of the sucker 23, and this digital signal indicating the position of the sucker 23 is compared with those boundary values.

Although not shown, this processor 45
Is supplied with an output signal from the syringe diameter detector, and information such as the volume and length of the syringe 3 mounted on the infusion device 1 is set therein. As described above, the processor 45 includes information such as the volume and length of the syringe 3 and the sucker 23 that moves.
The position information and the position information are input and the infusion flow rate and the like are displayed on the display device 18 based on these information.

Next, the operation of the infusion device 1 will be described. First, the syringe 3 containing a desired volume of drug solution or the like is placed on the placing portion 22 as shown in FIG. 2, and the outer cylinder 21 is pressed from above by the syringe retainer 26 and fixed to the infusion device 1. Then, the motor is started to drive the drive mechanism 2
When the slider 24 is moved in the direction of the arrow a in FIG. 2 by 5, the slider 24 comes into contact with the end of the sucker 23, and a load is generated on the slider 24. This load causes the feed screw 34
Moves to the right in FIG. 2 and presses the pressure sensor 40. The output of the pressure sensor 40 is also supplied to the processor 45, and the processor 45 determines the start of infusion.

Thereafter, as the sucker 23 is pushed by the slider 24 and moves at a constant speed in the direction of arrow a in FIG. 2, the chemical solution or the like flows out from the syringe 3 at a constant flow rate. And the sucker 23
The signal indicating the position of is continuously output from the encoder 27, is A / D converted, and is then supplied to the processor 45.

Next, in the processor 45, the flow rate of the drug solution or the like flowing out from the syringe 3 is measured based on the information from the encoder 27 or the like, and the infusion is completed when a predetermined volume is delivered. Since the load of the slider 24 is further increased when the sucker 23 comes into contact with the wall surface of the outer cylinder 21, the pressure sensor 40 can detect the increase of the load and complete the infusion.

In the infusion device 1 of this embodiment, since information indicating the position of the sucker 23 and information indicating the volume of the syringe 3 are input to the processor 45, the flow rate per unit time and the delivered volume can be accurately determined. Since the information that can be managed and the load of the slider 24 is also input to the processor 45, the delivery state of the drug solution or the like from the syringe 3 can be monitored and highly accurate infusion can be performed.

[0036]

Since the infusion device according to the present invention has the structure using the encoder as described above, the infusion operation can be accurately monitored while the structure is simple, and the life of the device can be improved because the non-contact pickup is used. Furthermore, since the pickup is optical, it is not affected by external noise.

Further, the structure of the encoder can be further simplified by using a flat reflection plate which is provided at a predetermined angle with respect to the moving direction of the pickup as the reflection plate used for the encoder.

Further, since the analog signal output from the encoder is converted into a digital signal by the A / D converter and the position of the moving sucker is detected, the encoder can be adjusted by circuit adjustment with almost no mechanical adjustment. Can be adjusted and the work in the manufacturing process of the infusion device can be facilitated.

Then, output from the encoder, A
If the D / D-converted digital signal is input to the processor together with various information using a multiplexer, the position information of the sucker can be processed together with various information in the processor, and a more accurate infusion operation can be easily realized. .

[Brief description of drawings]

FIG. 1 is an external perspective view of an infusion device using an encoder of the present invention.

FIG. 2 is a side view showing an encoder according to the present invention with a part of an infusion device cut away.

FIG. 3 is a side view showing an enlarged main part of the encoder shown in FIG.

FIG. 4 is a block diagram showing an embodiment of a detection unit to which a signal from an encoder according to the present invention is input.

[Explanation of symbols]

 3 Syringe 23 Absorber 25 Drive mechanism 27 Encoder 33 Reflector 33a Reflective surface 35 Pickup 36 Light emitting element 37 Light receiving element 38 Detection means 42 Preamplifier 43 Multiplexer 44 A / D converter 45 Processor

Claims (4)

[Claims] 1. A syringe that stores a liquid, a moving member that linearly moves between a first position and a second position at a predetermined speed by a drive mechanism, and a syringe member that interlocks with the moving member. A slider having a slider for pressing the sucker, a pickup having a light emitting element and a light receiving element attached to the moving member and moving between the first position and the second position, and light from the light emitting element to the light receiving element. The third position corresponding to the first position and the second position so that the optical path length thereof is reflected and corresponds to the position of the pickup.
An encoder including a reflector extending between the position and the fourth position, and the position of the sucker or the like is detected based on an electric signal output from the pickup according to an optical path length corresponding to the position of the pickup. An infusion device, each of which has a detecting means for 2. The reflection surface of the reflection plate is formed into a flat surface, and the reflection surface is inclined between the third position and the fourth position at a predetermined angle with respect to the moving direction of the pickup, and the pickup is provided. The infusion device according to claim 1, wherein the optical path length is increased or decreased depending on the position of. 3. The detection means includes an A / D converter to which an analog signal from the pickup is input, and a digital signal output from the A / D converter and a plurality of boundary values set to predetermined values. The infusion device according to claim 1, wherein the position and the like of the sucker are detected by comparing the above. 4. The detection means selectively outputs a preamplifier for adjusting the offset and span of the analog signal from the pickup and outputting the second analog signal adjusted within a predetermined voltage range by the preamplifier. A multiplexer, an A / D converter to which the second analog signal is input, and a processor in which a plurality of boundary values for setting a digital signal output from the A / D converter are set are provided respectively. The infusion device according to claim 1, wherein the position of the sucker is detected.