As a new type of instrument with small size, simple operation and easy to use, microinjection pump (injection pump for short) has been widely used in laboratory sample injection. It can make the liquid more accurate, trace, uniform and continuous into the target instrument, and can adjust the concentration and speed of the liquid at any time according to the experimental requirements, so as to maintain the effective concentration of the liquid in the experimental link.
In the experiment, when the micro pump is used to pump into the experimental target, the isotonic solution is usually dripped slowly in the same channel to keep the pipeline unobstructed, prevent the liquid from reflux as far as possible, and make the reflux liquid flow into the pipeline in time. Properly shorten the micro pump alarm delay time, so as to reduce the occurrence of pipe blockage and improve the safety of drug administration. So when the speed of the injection pump reaches how many milliliters, we can keep the pipe unobstructed without using intravenous drips of liquid?
In the current experimental process, it is still in the exploratory stage for how much the pump speed of the injection pump can reach without continuing the pump. Wang Jiaan et al have shown that in clinical work, appropriate vascular volume should be given when micro-pumping drugs are injected, preferably with a micro-pump or infusion pump at a constant speed, but vascular volume is not needed in all cases, only when the pumping speed is less than 9ml/h.
Whether or not to use the continuous pump liquid also needs to consider the following factors:
First, the difference between manufacturers.
The sensitivity of pressure alarm of injection pump with different specifications from different manufacturers is different.
Injection pump and blocking pressure gear.
A kind of injection pump has different blocking pressure gears and different blocking alarm pressure values, which is directly related to the set value of flow velocity.
Third, pressure alarm delay error.
JJF1259-2018 “Calibration Specification for Medical injection pumps and Infusion pumps” stipulates that the maximum allowable error of blockage alarm is ±13.33kPa (±100 mmHg) or ±30% of the setting value of blockage alarm, and the setting value of flow velocity and alarm response time are not clearly specified. However, the pressure value of blockage alarm is directly related to the setting value of flow velocity.
Fourth, extend the hardness of the tube.
The hardness of the pipeline has a great influence on the detection results of the blocking alarm pressure. The infusion extension tube with high hardness and low elasticity can detect the data of the microinjection pump more accurately.