JPH0436705B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infusion pump used for quantitatively administering a medicinal solution to a patient. More specifically, the present invention relates to an infusion pump using a tube pump that transfers a drug solution by squeezing a tube.

[Conventional technology]

Conventionally, in order to administer a predetermined amount of medicinal fluid into a vein at a constant rate, a medicinal solution bottle was hung at a high place, and the injection was performed while adjusting the flow rate with a clamp using the height difference from the patient. However, with this method, the flow rate fluctuates greatly over time and accurate infusion is difficult, so the use of infusion pumps, which perform infusion by attaching a pump to an infusion circuit, has been increasing in recent years. In infusions using such infusion pumps, tube occlusion detectors and bubble detectors are provided to ensure patient safety.

Conventionally used tube occlusion detectors, as described in JP-A-56-31758 and JP-A-56-13083, press the tube with a constant pressure to make it slightly depressed. When the tube is closed and the pressure inside the tube increases, the recessed portion is mechanically and electrically detected as it tries to recover.

[Problem to be solved by the invention]

Conventional tube occlusion detectors have had the disadvantage that the tube is required to be provided with the above-mentioned mechanical means, making the device bulky. In addition, the structure was complicated and manufacturing was troublesome.

[Means to solve the problem]

The present invention detects tube occlusion only by electrical means without providing mechanical means to the tube. To this end, a pulse motor is used as the drive source for the pump, and a phenomenon unique to the pulse motor is used to detect tube occlusion.

In other words, a pulse motor drives a motor by passing current in a pulsed manner at regular intervals.
The torque increases when the current flow time per pulse is increased, and the torque decreases when the current flow time is shortened. The ratio of the time during which this current is applied to the total time is called duty, and duty can be easily changed electrically. In the case of a pulse motor, if the load on the motor exceeds the torque, a phenomenon called slip occurs and the motor stops rotating. The present invention utilizes such a phenomenon to detect tube occlusion.

To specifically illustrate the present invention, in an infusion pump comprising a pump body for transferring a drug solution by squeezing a tube, and a pulse motor for driving the pump body, the pulse motor is a motor duty cycle pump. When performing infusion, the duty can drive the pump body when the tube is open, and when the tube is closed, the duty can be adjusted to a range where the motor slips, and the presence or absence of rotation of the motor can be detected. This infusion pump is characterized in that it detects tube occlusion.

[Effect]

In the infusion pump of the present invention, when the tube is open, the pump body can be driven, but when the tube is closed, the motor duty is adjusted to such a range that the motor slips. Stop. Therefore, if you constantly check the rotation of the motor electrically,
Can detect whether or not the tube is blocked.

〔Example〕

FIG. 1 is a block diagram schematically showing the present invention. The tube pump is composed of a pump body 1 that transfers liquid by squeezing the tube while rotating a plurality of rollers, a motor for driving the pump body 1, and a motor drive circuit that controls the drive of the motor. The control circuit instructs the motor rotation speed to achieve a predetermined flow rate, and this is sent as an electrical signal to the motor drive circuit to control the motor rotation speed. A means for detecting the presence or absence of rotation is connected to the motor, which checks the presence or absence of rotation and sends it as an electrical signal to the control circuit. If the tube is blocked for some reason, the motor will trip and stop, and the rotation detection means will send a signal indicating that the motor is not rotating to the control circuit. to instruct the alarm to activate the alarm.

FIG. 2 is a block diagram showing the configuration of the present invention more specifically. In this example, the presence or absence of rotation of the motor is monitored using an encoder and a counter.

FIG. 3 is an example of a circuit diagram of a pulse motor equipped with a variable duty circuit, and the duty is adjusted by adjusting the pulses generated by the pulse oscillator.

〔Effect of the invention〕

According to the present invention, there is no need to provide a mechanical means to the tube, and there is an advantage that blockage of the tube can be detected using only a simple electric means.

[Brief explanation of drawings]

FIG. 1 is a block diagram schematically showing an infusion pump of the present invention, and FIG. 2 is a block diagram that further embodies this. Figure 3 is a circuit diagram of a pulse motor equipped with a variable duty circuit.
This is an example.

Claims (1)

[Claims] 1. An infusion pump comprising a pump body that squeezes a tube to transfer a medicinal solution and a pulse motor for driving the pump body, the pulse motor comprising means for detecting whether or not the motor is rotating; Furthermore, when the tube is open, the pump body can be driven, and when the tube is closed, the pump duty is adjusted to a range where the motor slips.By detecting whether or not the motor is rotating, the pump body can be driven. An infusion pump characterized by being configured to detect.