medical Syringe pumps and Infusion pumps have very precise flow control requirements, and the slight errors in measurement may affect the treatment effect and safety of patients, and the flow accuracy has a very important impact on the health and safety of patients. The quality of its technical performance will directly affect the quality of medical care, and it is important to regularly inspect syringe pumps and infusion pumps. The following introduces the working principle of Medical syringe pumps and infusion pumps, and discusses the problems encountered in the calibration process of medical infusion pumps and syringe pumps, and proposes solutions.

In 2010, China promulgated and implemented JJFl259-2010 "Calibration Specification for Medical Syringe Pumps and Infusion Pumps", and began to effectively supervise and control the performance and quality of medical syringe pumps (infusion pumps), and then revised them, and now the new industry standard is "JJF 1259-2018 Calibration Specifications for Medical Syringe Pumps and Infusion Pumps". At present, the metrology and verification departments across the country have widely carried out the calibration of medical syringe pumps (infusion pumps), and the main calibration items include pre-calibration inspection, flow error and blocking alarm error. Among them, the inspection before calibration is subdivided into visual inspection, patient leakage current inspection, door opening alarm, bubble alarm, alarm before the end of injection, alarm after injection completion, power cord off alarm and syringe identification.

Considerations for Calibrating Medical Syringe Pumps and Infusion Pumps:

At present, medical syringe pumps and infusion pumps are widely used in various medical departments of hospitals and are frequently used. Through the detection of medical syringe pumps and infusion pumps in major hospitals, it is found that the medical syringe pumps and infusion pumps with large infusion flow error deviations in various hospitals are not only due to the problems of the instrument itself, but also related to the use and maintenance of the instrument. There are many factors that affect the performance of medical syringe pumps and infusion pumps, and the following factors need to be paid attention to in the testing process in order to do a good job in the calibration and testing of medical syringe pumps and infusion pumps.

1. Infusion equipment needs to be matched

The size of the infusion error of infusion pump and syringe pump is related to the material elasticity, thickness, pipe diameter and production process of infusion set and syringe. However, when the infusion pump syringe pump is set up at the factory, it is generally the original accessory by default, which leads to significant differences in the infusion accuracy of infusion sets and syringes from different manufacturers. The original infusion set and syringe matched with the infusion pump syringe pump have obvious advantages in both the overall error range and the error distribution range, so it is necessary to pay attention to the matching of the infusion equipment and the infusion pump syringe pump in the calibration process. When a mismatch is found during the testing process, it is necessary to adjust the parameters on the infusion pump and syringe pump (infusion sets and syringes from different manufacturers generally have specific codes) to make the two match.

2. The detection medium must meet the requirements

Because most of the valves in the infusion pump and syringe pump detector are made of high-quality stainless steel, they are not completely rust-proof. When such valves are exposed to salt solutions and oxygen dissolved in water for long periods of time, corrosive pitting can occur, so the use of normal saline as a test fluid is not recommended. Similarly, tap water contains a small amount of minerals, which will cause an opaque film to form on the glass tube wall in the instrument after long-term use, which will affect the precision of the instrument. Therefore, medical syringe pumps and infusion pumps need to use deionized water or distilled water for calibration, so as to extend the life of the valves in the standard, ensure the precision of the instrument, and ensure the trouble-free operation of the instrument.

3. The flow detection needs to be stable

Medical infusion pumps and syringe pumps require a process from the beginning of infusion to stabilization to the set infusion rate. During this process, the infusion rate slowly rises to the set parameters and eventually stabilizes. In the actual test, we found that this process is common in medical infusion pumps and syringe pumps produced by different manufacturers, and the length of time is different. In order to ensure the reliability and accuracy of the test, when testing the measured value of medical infusion pump and syringe pump, the value must be recorded only after the flow rate is stable, and each flow point must be measured at least 3 times.

4. Calibration is required to improve the accuracy of infusion

In the actual test, we found that after many years of use, medical infusion pumps and syringe pumps generally have various problems, resulting in poor infusion accuracy. The medical syringe pump is driven by the rotation of the screw to drive the piston for injection, due to the frequent use and poor maintenance, after a long period of use, there are some coagulated drugs on the screw of the medical syringe pump, resulting in poor screw pushing, so that the infusion accuracy of the syringe pump becomes poor. To do this, it is necessary to scrub with alcohol and gasoline and then make a calibration measurement. Medical infusion pumps generally use finger peristaltic pumps as the power source, and by squeezing the medical infusion pump pipeline, peristaltic movement is generated, thereby pushing the liquid forward flow. After long-term use, the camshaft or extrusion strip inside will be aged and worn, and the elasticity of the spring will deteriorate, which will reduce the accuracy of the infusion. It needs to be recalibrated during the inspection, and the error is eliminated by the software setting method.

5. The alarm inspection should be comprehensive

In the design of medical infusion pumps and syringe pumps, many sound and light alarm functions are adopted, and the detection of these alarm functions is also very important in the calibration process of medical syringe pumps and infusion pumps. The inspection of alarm functions such as door opening alarm, alarm before the end of injection, alarm after injection, power cord off alarm and syringe identification is relatively simple, and it can be operated in accordance with the regulations, only the inspection of bubble alarm needs special attention. The method of detecting air bubbles in medical infusion pumps is mainly ultrasonic detection technology, which detects the existence of air bubbles through the change of sound impedance. Therefore, the cause of the bubble alarm is sometimes not the presence of air bubbles in the tubing, but the material of the infusion tube. The silica gel content in the infusion tube directly affects the elastic coefficient of the pipeline, and some infusion tubes with relatively low silica gel content will not rebound in the tube wall during long-term use, resulting in a bubble alarm generated by the medical infusion pump. In this case, a new infusion line will need to be replaced. In addition, there is talcum powder on the surface of some special silicone tubing, and if there is too much talcum powder, it will also cause bubble alarm of medical infusion pumps. In this case, the tubing should be removed, wiped with alcohol, and re-installed for testing.