JP2011206399A - Medical solution feeder - Google Patents

Abstract

A chemical solution injection device capable of detecting the pressure of a chemical solution without interrupting treatment or diagnosis even when the pressure sensor fails.
The chemical injection device includes a method for determining whether the pressure of a chemical obtained based on a detection value of a pressure sensor is within a predetermined range (a detection method using a pressure sensor), and a current detection unit. It is configured so that detection can be carried out by both a method for determining whether the pressure of the chemical liquid obtained based on the detection value is within a predetermined range (a detection method using a motor current) and a method. In any method, when it is determined that the detected pressure value is not within the predetermined range, a process of issuing a warning or stopping the injection of the chemical solution is performed.
[Selection] Figure 2

Description

  The present invention relates to a chemical solution injection apparatus having a pressure sensor for detecting the pressure of a chemical solution at the time of injection of the chemical solution, and in particular, performs safe chemical injection without interrupting treatment or diagnosis even when the pressure sensor fails. The present invention relates to an apparatus for injecting a chemical solution.

At present, CT (Computed Tomography) scanner, MRI (Magnetic Resonance Imaging) apparatus, PET (Positron) as medical diagnostic imaging equipment.
Emission Tomography) devices are known. When using such an imaging apparatus, a subject may be injected with a contrast medium, physiological saline, or the like (hereinafter, also simply referred to as “medical solution”). Conventionally, various injectors (injection heads) that automatically execute this injection have also been proposed.

The injection head generally includes a syringe holding unit to which a syringe is attached and a piston drive mechanism that pushes a piston member of the syringe, and injects a drug solution in the syringe into a subject by operating the piston drive mechanism.
Patent Document 1 discloses a chemical liquid injection device in which a load cell is provided in this piston drive mechanism, and a chemical liquid pressure in a syringe is calculated by detecting a force pushing a piston member with this load cell.

JP2003-290343

  Even in the conventional chemical liquid injector as described above, the chemical pressure can be well detected using the load cell. However, when the load cell fails, it is impossible to perform a procedure or diagnosis that requires contrast medium injection until the load cell is repaired or replaced. If the chemical solution injection is executed without noticing the failure, the injection may be performed at an abnormal pressure or the syringe may be damaged.

  This invention is made in view of the said subject, The objective is to provide the chemical | medical solution injection | pouring apparatus which can perform safe chemical | medical solution injection | pouring without interrupting treatment and a diagnosis at the time of a failure of a pressure sensor. is there.

The chemical injection device of the present invention for solving the above problems is
A piston drive mechanism having a motor as a drive source and pushing the piston member of the syringe;
A pressure sensor for detecting a force by which the piston driving mechanism pushes the piston member;
Current detecting means for detecting a current flowing through the motor;
A chemical injection device comprising:
A detection value of the pressure sensor, or a method of determining whether the pressure of the chemical liquid obtained based on the detection value is within a predetermined range (detection method by the pressure sensor);
A method of determining whether the detected value of the current detection means, or the pressure of the chemical obtained based on the detected value is within a predetermined range (detection method by motor current);
It is configured so that detection by both methods can be performed,
In any one of the above methods, when it is determined that the detected value or the pressure value is not within a predetermined range, at least one of a process for issuing a warning, a process for stopping chemical injection, and a process for keeping the pressure constant. A chemical injection device that performs one.

“Determining whether or not the detected value of the pressure sensor or the pressure of the chemical obtained based on the detected value is within a predetermined range” means that the detected value (electric signal) of the sensor itself is It is intended that the determination may be performed using an index, or the pressure value corresponding to the detected value may be obtained and the determination may be performed using the magnitude thereof. The same applies to the current detection means.
“Processing for keeping the pressure constant” means controlling the operation of the piston drive mechanism so that the pressure of the detected chemical solution is within a predetermined range.
The “warning” may be audibly recognized (for example, a warning by sound) or may be visually recognized (for example, by a message displayed on a display or the like). warning).

  According to the present invention, both the detection method using the pressure sensor and the detection method using the motor current are provided and can be switched, so that either one (for example, the pressure sensor) has failed. On the other hand, pressure detection can be performed.

In another chemical liquid injector of the present invention,
In the initial setting, the detection method by the pressure sensor is set to be used,
further,
Processing to determine whether or not the pressure sensor is faulty;
As a result, when it is determined that there is a failure, a process of switching the setting so that the detection method using the motor current is used,
I do.
According to such a configuration, when the pressure sensor fails, it is automatically switched to the detection method based on the motor current, so that there is no need for the operator to perform a special operation to switch the detection method.

In another chemical liquid injector of the present invention,
The process for determining whether or not the pressure sensor has failed is:
This is automatically performed in a step prior to the step of injecting the chemical into the subject.

In another chemical liquid injector of the present invention,
Both the detection method by the pressure sensor and the detection method by the motor current are configured to be implemented,
further,
A process of comparing the pressure value obtained by the detection method using the pressure sensor with the pressure value obtained by the detection method using the motor current;
A process for issuing a warning about the motor when the difference between the pressure values is larger than a predetermined value;
I do.
“Motor warning” refers to a warning prompting replacement of motor parts or a warning prompting motor maintenance.

In another chemical liquid injector of the present invention,
Both the detection method by the pressure sensor and the detection method by the motor current are configured to be implemented,
further,
A process of comparing the pressure value obtained by the detection method using the pressure sensor with the pressure value obtained by the detection method using the motor current;
When the difference between the pressure values is larger than a predetermined value, the correction mode (the detected value of the current detection means or the pressure obtained based on the detected value so that the difference in the pressure values is within an appropriate range) To turn on the mode to correct the value)
I do.

  According to such a configuration, even when the aging of the motor has progressed, it is possible to maintain the same accuracy as the detection method using the pressure sensor without reducing the accuracy of pressure detection using the motor current. .

  As described above, according to the present invention, it is possible to provide a chemical injection device that can perform safe chemical injection without interrupting treatment or diagnosis even when a pressure sensor fails.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a chemical liquid injector according to one embodiment of the present invention and a fluoroscopic imaging system including the same. It is a schematic diagram which shows typically the structure of a chemical injection device. It is a flowchart which shows an example of operation | movement of a chemical injection device. It is a schematic diagram which shows the other example of operation | movement of a chemical injection device. It is a flowchart which shows the other example of operation | movement of a chemical injection device.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
As shown in FIG. 1, the fluoroscopic imaging system includes a chemical liquid injector 100 and a fluoroscopic imaging device 300 interconnected therewith. The chemical solution injection device 100 has an injection head 110 for injecting a contrast medium or the like to a subject, and a controller device 50 connected thereto.

  As an example, the fluoroscopic imaging apparatus 300 includes a bed 303 on which a subject is placed and moves in a horizontal direction, an apparatus main body 302 that captures a fluoroscopic image of a subject, a control unit (not shown) having a monitor, a keyboard, and the like. It has.

As the injection head 110, a conventional one can be used. In this example, a two-cylinder injection head to which a syringe A filled with a contrast medium and a syringe B filled with physiological saline are mounted is used. It's being used.
As an example, the injection head 110 is held on an upper part of a caster stand. As shown in FIG. 2, this injection head has piston drive mechanisms 120A and 120B (hereinafter also simply referred to as “piston drive mechanism 120”) for pushing in the piston members of the syringes A and B. Each piston drive mechanism has a motor 121 as a drive source, a link mechanism 122 for transmitting a force from the motor, and a member 123 that moves forward and backward by receiving the force transmitted by the link mechanism. ing. A load cell 128 for detecting a force pushing the piston member of the syringe is provided between the member 123 that moves forward and backward and the piston member of the syringe. As will be described later, the pressure of the chemical solution can be calculated based on the detected value of the load cell 128.

  The injection head 110 may have a tag reader for reading information of an IC tag attached to a part of the syringe. The IC tag may store information related to the syringe (syringe identification data, cylinder member pressure resistance, cylinder member inner diameter, piston member stroke, and the like). In the case of the prefilled type, information (for example, product name, component information, viscosity, expiration date, etc.) of the chemical solution filled in the syringe may be stored.

  As shown in FIG. 1, the controller device 50 has a touch panel display 51. For example, an image for setting injection conditions is displayed on the display 51. The display 51 may also display information on the chemical solution in the syringe, information on the pressure of the chemical solution during the injection of the chemical solution, and the like.

The controller device 50 performs a process of receiving input of various information via the touch panel, a process of performing a predetermined calculation based on the input information, a process of controlling the operation of the injection head 110, and the like. The part 55 (refer FIG. 2) is incorporated.
The control unit 55 may be a so-called one-chip microcomputer, and a CPU (Central
A processing unit (ROM), a read only memory (ROM), a random access memory (RAM), and an interface (I / F) are included. The computer unit stores a predetermined program in an information storage medium such as a ROM, and the CPU executes various processes corresponding to the program.

  As shown in FIG. 2, the control unit 55 is connected to each motor 121 of the piston drive mechanism, whereby the control of the operation of each motor 121 is performed by the control unit 55. A current detection unit 125 is connected to the motor 121, and a detection value of the current detection unit 125 is acquired by the control unit 55.

The controller 55 is configured to be able to detect the chemical pressure by two methods.
One is a method for obtaining the pressure of the chemical solution based on the detection value of the load cell 128 (hereinafter, referred to as a “detection method using a load cell”). In this method, the pressure of the chemical solution close to the actual pressure can be obtained as compared with the “detection method using motor current” described below.

The control unit 55 performs a process of determining whether or not the pressure value obtained by this method is within a predetermined range, and if it is determined that the value is not within the predetermined range, issues a predetermined warning or Processing to stop chemical injection is performed. Alternatively, a process for keeping the pressure constant may be performed.
Thereby, the injection | pouring by abnormal pressure is prevented and the bad injection | pouring with respect to a test subject can be prevented beforehand.

  The other is a method for obtaining the pressure of the chemical solution based on the detection value of the current detection means 125 (hereinafter referred to as “detection method using motor current”). In general, the current flowing through the motor 121 increases as the load applied to the motor increases, and decreases as the load decreases. Using this, in the detection method using the motor current, a pressure value corresponding to the detected motor current is calculated.

  The control unit 55 performs a process of determining whether or not the pressure value obtained by this detection method is within a predetermined range, and if it is determined that the pressure value is not within the range, as described above, issues a predetermined warning or Processing to stop chemical injection is performed. Or the process which keeps the pressure of the chemical | medical solution detected constant is performed.

  In addition, the chemical injection device may be set to perform pressure detection using both of the two methods, or may be set to perform pressure detection using only one of them. .

  Next, the operation of the chemical liquid injector of the present embodiment configured as described above will be specifically described. In addition, the process demonstrated below is only an example, Comprising: This invention is not limited by the order etc. which perform each process. In the following example, it is assumed that a detection method using a load cell is initially set as a method for detecting pressure.

  First, as shown in FIG. 3, the injection conditions are set by the operator (step S1). For example, the setting of the injection conditions may be performed by the operator inputting the weight of the subject, the imaging region, and the like through the touch panel display 51 of the controller device 50.

When the setting of the injection conditions is completed, a self-check is then performed by the chemical solution injection device 100 (step S2). This self-check is for determining whether or not the load cell 128 of the piston drive mechanism 120 is out of order, by a conventionally known method (for example, by electrically checking the resistance balance of the load cell 128). To be implemented.
As an example, the self-check may be started when the operator presses a predetermined image button on the display 51 after setting of the injection conditions is completed. Alternatively, it may be automatically performed at a predetermined timing after the setting of the injection conditions is completed.

  As a result of this self-check, when it is determined that the load cell 128 is out of order, the chemical injection device 100 displays a predetermined warning on the display 51 of the controller device 50 (step S3). This warning may be, for example, a message that the load cell may be broken, or a message that prompts repair or replacement of the load cell.

  Next, the chemical liquid injector 100 switches from the detection method using the load cell to the detection method using the motor current (step S4). Since such switching is automatically performed, even if the load cell is out of order, the pressure of the chemical solution can be detected well as described below without being affected by the failure.

  Next, chemical injection is performed (step S5). In this chemical injection, the motor 121 is driven under the control of the control unit 55. While the motor 121 is being driven, pressure detection based on the motor current is performed. Specifically, the current of the motor 121 is detected by the current detection means 125, and the control unit 55 obtains the detected value and obtains the pressure value of the chemical solution in the syringe based on the detected value. The obtained pressure value is displayed on the display 51 of the controller device 50. In addition, this pressure value may be displayed as a numerical value and may be displayed as a graph. If both the pressure value obtained by the detection method using the load cell and the pressure value obtained by the detection method using the motor current are displayed on the display, each pressure value is preferably displayed in a different color.

  The control unit 55 performs a process of determining whether or not the obtained pressure value is within a predetermined range. If it is determined that the pressure value is not within the predetermined range, for example, a predetermined message is displayed on the display 51 of the controller device 50. A warning is issued by displaying. Furthermore, chemical solution injection may be automatically stopped.

  When a predetermined amount of chemical solution is injected, the chemical solution injection is completed.

  According to the chemical injection device of the present embodiment configured as described above, both the detection method by the load cell and the detection method by the motor current are provided, and they are switchable, so the load cell has failed. Even in this case, pressure can be detected by the other method (detection method using motor current). Therefore, it is possible to continue the safe chemical injection to the subject without stopping the treatment or diagnosis.

In particular, in this embodiment, as shown in steps S2 to S4 of FIG. 3, the chemical injection device automatically performs a self-check (S2), and automatically switches to a detection method based on a motor current when a load cell fails ( S3). Therefore, there is no need for the operator to perform a special operation for switching the detection method, and a safer and easier-to-use chemical liquid injector can be provided.

In addition, when the detection value from a load cell is not obtained during chemical | medical solution injection | pouring, it may be determined that the load cell has failed, and the detection method using the load cell may be automatically switched from the detection method using the motor current.
According to this, even if the load cell fails after the self-check (step S3) as shown in FIG. 3, switching to the detection method based on the motor current can be performed in response to the failure.

  Further, the timing at which the self-check is performed is not limited to the timing at step S2 in FIG. 3, but is performed before the injection conditions are set (for example, when the power of the chemical injection device is turned on). It may be.

[Other operation example 1]
Advantages of having both the detection method using the load cell and the detection method using the motor current include the following.
That is, in general, the detection method based on the motor current has an advantage that it can be manufactured at a lower cost than the load cell, but the detection method based on the motor current is used when the motor is not driven (that is, no current flows through the motor). ) Has a problem that pressure cannot be detected. On the other hand, according to the detection method using a load cell, pressure can be detected even when the motor is not driven, but there is a problem in cost because the load cell is relatively expensive. As described above, each detection method has advantages and disadvantages. However, when both methods are provided as in the present embodiment, a chemical solution injection device that is more user-friendly according to the demands of the medical site is provided by appropriately using them. can do.

For example, as shown in FIG. 4, consider a case in which the chemical solution of syringe A out of two syringes A and B is being injected into a subject. In this example, Y-shaped chemical liquid tubes 161 are connected to the syringes A and B, and a switching valve or the like is not provided at the branching portion 161a.
In such a configuration, if only the piston drive mechanism (not shown) on the syringe A side is operated while the piston drive mechanism (not shown) on the syringe B is stationary, the chemical solution in the syringe A rises. At the same time, the pressure of the chemical solution in the syringe B also increases, and in some cases, the piston member of the syringe B may be pushed out (pushed back). In this case, for the following reason, basically, the pressure of the chemical solution in the syringe B cannot be detected by the detection method using the motor current. That is, depending on the specifications of the chemical injection device, when the piston member is pushed back and the motor rotates in reverse, it is generally determined that some error has occurred and pressure detection is not performed. Because.

Therefore, in this case, it is preferable that the pressure of the chemical solution in the syringe B is detected by the load cell. Thereby, even if it is a case where the pressure of the chemical | medical solution in the syringe B rises by the above phenomena, the pressure of the chemical | medical solution in the syringe B can be detected favorably.
In the case of the configuration of FIG. 4, since the pressure of the chemical solution in the syringe A and the pressure of the chemical solution in the syringe B are basically the same, the pressure of the chemical solution in both the syringes A and B should be detected by one load cell. There is also an advantage of being able to.

  Note that the phenomenon in which the syringe B is pushed back as described above is not limited to the time when the chemical liquid in the syringe A is being injected, but may also be caused by the residual pressure after the chemical liquid is injected.

Focusing on the point of detecting the pressure of both the syringes A and B with one load cell,
This chemical injection device
A syringe holding unit for holding two syringes;
Two piston drive mechanisms that push in the piston member of each syringe;
A pressure sensor (load cell) provided in at least one of the two piston drive mechanisms for detecting the force by which the piston drive mechanism pushes the piston member;
May be provided.

  This chemical injection device performs a process of detecting the pressure of the chemical in both syringes with one load cell.

[Other operation example 2]
The chemical liquid injector 100 shown in FIGS. 1 and 2 may further perform the following operation. In general, in the case of a detection method using a motor current, when the motor deteriorates over time, the value of the motor current detected by the current detection means changes, resulting in a large error between the actual chemical pressure and the calculated pressure. May be. The following operations are for reducing such errors.

  In this example, first, both the pressure detection by the motor current and the pressure detection by the load cell are performed, and the respective pressure values are obtained. Then, as shown in FIG. 5, the pressure values are compared (step S11).

Next, it is determined whether or not the difference is larger than a predetermined value (step S12). If the difference is smaller than the predetermined value, it is considered that the pressure detection based on the motor current is normally performed, and thus the process ends at this point.
On the other hand, if the difference is larger than the predetermined value, it is considered that the aging of the motor is progressing. Therefore, in this case, for example, a warning prompting replacement of a motor part or a warning prompting motor maintenance ( Step S13).

Next, a mode (hereinafter referred to as “correction mode”) for correcting the pressure value obtained by pressure detection by the motor current is turned on so that the difference between the pressure values is within an appropriate range (step S14).
When pressure detection based on the motor current is performed with this mode turned on, the detection value of the current detection means or the pressure of the chemical obtained based on the detection value is corrected according to a predetermined algorithm.

The “predetermined algorithm” is an algorithm for bringing the pressure value obtained by pressure detection by the motor current closer to the pressure value obtained by pressure detection by the load cell. As an example, using a predetermined calculation formula, You may correct | amend a detected value or a pressure value corresponding to it.
By performing such correction, it is possible to perform highly accurate pressure detection with a small difference from the actual pressure even if the motor has deteriorated over time.

  A series of steps for determining whether or not the motor has deteriorated as shown in FIG. 5 and turning on the correction mode as necessary is automatically and periodically performed by the chemical injection device. It is preferable that it is adapted. In order to realize this, the chemical injection device may include a timer for measuring the total usage period, for example. Or the chemical injection device may have a built-in counter for counting the number of times of use.

While one embodiment of the present invention has been described above, the present invention is not limited to the above and can be variously modified.
For example, instead of the two-tube injection head 110 as shown in FIGS. 1 and 2, a single-tube injection head may be used. 2 may be built in the injection head 110. FIG. The controller device 50 may be provided as an independent device, or may be provided as a part of the function of another device. For example, a controller device may be incorporated in a part of the control device of the fluoroscopic imaging device.

In the above description, a plurality of steps are described in order, but as described above, the description order does not limit the order in which the plurality of steps are performed. For this reason, when implementing the data processing method of this invention, the order of the some process can be changed in the range which does not interfere in content.
The data processing method of the present invention is not limited to being executed at a timing when a plurality of steps are different from each other. For example, another process may be performed during execution of a certain process.

50 controller device 51 display 55 control unit 100 chemical solution injection device 110 injection head 121 motor 122 link mechanism 125 current detection means 128 load cell 161 chemical solution tube 300 fluoroscopic imaging device 302 device main body 303 bed A, B syringe

Claims (7)

A piston drive mechanism having a motor as a drive source and pushing the piston member of the syringe;
A pressure sensor for detecting a force by which the piston driving mechanism pushes the piston member;
Current detecting means for detecting a current flowing through the motor;
A chemical injection device comprising:
A detection value of the pressure sensor, or a method of determining whether the pressure of the chemical liquid obtained based on the detection value is within a predetermined range (detection method by the pressure sensor);
A method of determining whether the detected value of the current detection means, or the pressure of the chemical obtained based on the detected value is within a predetermined range (detection method by motor current);
It is configured so that detection by both methods can be performed,
In any one of the above methods, when it is determined that the detected value or the pressure value is not within a predetermined range, at least one of a process for issuing a warning, a process for stopping chemical injection, and a process for keeping the pressure constant. A chemical injection device that performs one. In the initial setting, the detection method by the pressure sensor is set to be used,
further,
Processing to determine whether or not the pressure sensor is faulty;
As a result, when it is determined that there is a failure, a process of switching the setting so that the detection method using the motor current is used,
The chemical | medical solution injection device of Claim 1 which performs. The process for determining whether or not the pressure sensor has failed is:
The chemical injection device according to claim 2, which is automatically performed in a step prior to the step of injecting a chemical into a subject. Both the detection method by the pressure sensor and the detection method by the motor current are configured to be implemented,
further,
A process of comparing the pressure value obtained by the detection method using the pressure sensor with the pressure value obtained by the detection method using the motor current;
A process for issuing a warning about the motor when the difference between the pressure values is larger than a predetermined value;
The chemical injection device according to any one of claims 1 to 3, wherein: Both the detection method by the pressure sensor and the detection method by the motor current are configured to be implemented,
further,
A process of comparing the pressure value obtained by the detection method using the pressure sensor with the pressure value obtained by the detection method using the motor current;
When the difference between the pressure values is larger than a predetermined value, the correction mode (the detected value of the current detection means or the pressure obtained based on the detected value so that the difference in the pressure values is within an appropriate range) To turn on the mode to correct the value)
The chemical injection device according to any one of claims 1 to 3, wherein:   The chemical injection device according to any one of claims 1 to 5, wherein the pressure sensor is a load cell. Two piston drive mechanisms are provided,
A syringe filled with physiological saline and a syringe filled with contrast medium are attached.
The chemical injection device according to any one of claims 1 to 6.

Images