What is an infusion pump?

An infusion pump is a medical device used to control and regulate the speed and flow of intravenous infusion to ensure that patients receive the correct dose of liquid medicine or solution according to the doctor's instructions. It is one of the important equipment commonly used in hospitals, emergency centers and other medical institutions.

1. Introduction
Infusion pumps are usually mechanical or electronic control devices that control the infusion speed by acting on the infusion catheter. They are often used in situations where the infusion volume and drug dosage need to be strictly controlled, such as when using pressor drugs, antiarrhythmic drugs, intravenous infusion of infants or intravenous anesthesia. The following is a discussion of the issues that should be paid attention to in the daily operation, maintenance and preservation of infusion pumps in combination with clinical practical applications.

2. Concept
Intravenous infusion is a commonly used method of drug administration in clinical treatment. Depending on the nature of the drug and the patient's physique, the speed of intravenous infusion is also different. Too fast or too slow infusion is difficult to achieve the expected therapeutic effect, and even affects nursing safety.

At present, the common infusion devices widely used in clinical practice mainly rely on the pressure of liquid level difference to input liquid into the receptor, and rely on the nursing staff to observe with the naked eye and manually adjust the wheel clamp to control the infusion speed. Ordinary infusion devices lack functions such as blockage alarm, bubble alarm, and liquid infusion alarm, which increases the burden of clinical nursing; and the liquid bottle is easy to introduce external air to contaminate the liquid. Infusion pump An infusion pump is an instrument that can accurately control the number of infusion drops or the infusion flow rate to ensure that the drug can enter the patient's body at a uniform speed, accurate and safe. It is also an intelligent infusion device. The infusion speed is not affected by the back pressure of the human body and the operator. The infusion is accurate and reliable, which helps to reduce the intensity of clinical nursing work and improve the accuracy, safety and quality of infusion.

Infusion pumps have various product models and different performances. According to their working characteristics, they can be divided into three categories: peristaltic control infusion pumps, constant volume control infusion pumps and syringe micro-injection infusion pumps.

3. Operation
Prepare the liquid medicine in the treatment room according to the doctor's instructions, check the quality, deterioration, discoloration, turbidity, looseness of the bottle mouth, and expiration date of the liquid medicine, saw it open after it is correct, disinfect it with an Andofu cotton swab, aspirate the liquid medicine, add the medicine and mix it according to the principle of aseptic operation. Write the name, bed number, name of the added drug, and dosage on the bottle label. Ask a second person to check and assist the patient to take a comfortable lying position.
Adjust the infusion speed and the scheduled infusion volume according to the doctor's instructions (press the 'select' on the infusion pump panel to adjust).
Tie the tourniquet, select the blood vessel correctly, loosen the tourniquet, disinfect the skin with Andofu, wait until it is dry, prepare the infusion patch, tie the tourniquet, disinfect the skin with Andofu again, puncture, and fix it correctly (same as the infusion operation procedure).
Record the drug, liquid volume, and infusion speed in the infusion pump.

4. Maintenance

To extend the service life of the infusion pump and maintain its infusion stability, please follow the following precautions:
Prevent any solid particles from entering the infusion pump body, because dust or any other impurities will wear the plunger, sealing ring, cylinder and one-way valve, so any solid particles in the mobile phase should be removed in advance. The mobile phase is best distilled in a glass container, and the commonly used method is filtration, which can be used with filters such as Millipore filter membranes (0.2um or 0.45um). The inlet of the pump should be connected to a sand filter rod (or sheet), and the filter of the infusion pump should be replaced frequently.
The mobile phase should not contain any corrosive substances, and the mobile phase containing buffer should not be retained in the pump, especially when the pump is stopped overnight or longer. If the mobile phase containing buffer is left in the pump, tiny salt crystals may precipitate due to evaporation or leakage, or even just due to the stillness of the solution. These crystals will damage the sealing ring and plunger, etc. like the above-mentioned solid particles. Therefore, pure water must be pumped in for thorough cleaning, and then replaced with a solvent suitable for column storage and pump maintenance (for reversed-phase bonded stationary phases, it can be methanol or methanol and water).
When the infusion pump is working, be careful to prevent the mobile phase in the solvent bottle from running out, otherwise the empty pump operation will also wear the plunger, sealing ring or cylinder, and eventually cause leakage.
The working pressure of the infusion pump should not exceed the specified maximum pressure, otherwise it will cause the high-pressure sealing ring to deform and cause leakage.
The flow box should be degassed first to avoid bubbles in the pump, which will affect the stability of the flow rate. If there are a large number of bubbles, the pump will not work.
If the infusion pump fails, the cause must be found out and appropriate measures must be taken to eliminate the fault:
No mobile phase flows out and there is no pressure indication. The reason may be that there is a large amount of gas in the infusion pump. At this time, the pressure relief valve can be opened to make the pump run at a larger flow rate (5ml/min) to exhaust the bubbles. A 50ml syringe can also be used to help extract the gas at the pump outlet. Another reason may be that the sealing ring is worn and needs to be replaced.
The pressure flow is unstable. The reason may be bubbles, which need to be eliminated, or there are foreign objects in the one-way valve. The one-way valve can be removed, immersed in acetone, and ultrasonic cleaning. Sometimes there may be bubbles in the sand filter rod or it may be partially blocked by tiny crystals of salt or growing microorganisms. At this time, remove the sand filter rod and immerse it in the mobile phase, ultrasonically remove bubbles, or immerse the sand filter rod (sheet) in dilute acid (such as 4mol/L nitric acid) to quickly remove microorganisms or dissolve salt, and then clean it immediately.
The reason for the high pressure is that the pipeline is blocked and needs to be cleared or cleaned. The reason for the reduced pressure may be that the pipeline is leaking. Check for blockage or leakage section by section. 5. Storage
When operating the infusion pump, do not touch the power plug with wet hands, and do not use it under direct sunlight or strong light. The sensor plug must be plugged in tightly when in use, otherwise it will not work properly. When not in use, put it on the seat at the top of the infusion pump and lock it to avoid damage during moving and storage. When charging, turn off the power switch before charging. If you use it for the first time or use it again after a long period of non-use, fully charge the battery before starting to use it. This infusion pump is prohibited from being stored in a place where it is directly blown by cold and wet (hot) airflows such as fans, air conditioners, electric stoves, heaters, humidifiers, etc. 6. Common faults and solutions of infusion pumps
Common alarms of infusion pumps:
Bubble alarm
Cause of fault: There are bubbles in the pipeline, and the liquid in the solution bottle or bag is empty;
Solution: Open the door to remove the pump tube, discharge the bubbles, and replace the new infusion bottle;
Battery low voltage alarm
Cause of fault: The battery/accumulator is low in power, and the battery charging is invalid;
Solution: Connect the AC power supply and replace the same type of battery;
Drop count alarm
Cause of fault: The liquid in the infusion bottle or bag is empty, the flow rate regulator is not opened, the small cap is not opened when exhausting, the sensor is placed incorrectly, the sensor is damaged, the drip pot is unstable, there is swinging, there is water mist in the drip pot, and the liquid level in the drip pot is too high;
Solution: Replace the new infusion, open the flow rate regulator, open the exhaust cap, place it correctly, clamp the sensor on the drip pot, replace the sensor, fix the infusion pot, keep it stable, shake the drip pot, remove the water mist, the liquid level in the drip pot cannot exceed 1/2 of the drip pot height, and the infusion Place the bottle upright, and then squeeze some of the liquid back into the bottle to lower the liquid level;
Maintain the opening rate
Failure cause: The liquid in the infusion bottle or bag is empty;
Handling method: Replace the infusion or stop the infusion according to the doctor's advice;
Pressure, blockage alarm
Failure cause: The flow rate regulator (screw clamp) is not loosened, the infusion tube is folded or compressed; blood clots block the venous access, and the proximal blood vessel pressure is too high;
Handling method: Loosen the flow rate regulator (screw clamp), remove the fold or pressure of the infusion tube, remove the blood clot, loosen the tourniquet, wear clothes with wide cuffs, and avoid measuring blood pressure on the infusion limb side;

7. Features
The infusion pump can achieve the following functional features:
(l) Accurately measure and control the infusion speed;
(2) Accurately measure and control the infusion volume;
(3) Can report abnormal conditions such as bubbles, empty liquid, leakage and infusion tube blockage, and automatically cut off the infusion access;
(4) Color OLED display;
(5) Realize intelligent control of infusion. The product functions cover the basic functions of many popular products on the market and have certain potential market value.

Scope of technical application: Looking at the current people who lack exercise and have poor resistance and are prone to illness, you can often see a large number of people receiving intravenous drips in hospitals. Now there are also many patients who need to receive intravenous drips slowly at a certain speed due to special diseases. If they rely solely on nurses to watch, the workload of nurses is very large, and it is easy to produce human errors. Therefore, a medical instrument that can run and control the speed and time of intravenous drips according to the nurse's wishes is needed.

In the research and development of biopharmaceuticals and chemical industries, for example, some liquid drug raw materials must be configured according to strict proportions. The most common configuration is now a test tube dropper configuration. This method of configuration through the human eye has many disadvantages and large errors. It is difficult to grasp the proportion of drug components, so an instrument that can accurately measure the output liquid is needed.

8. Types

Fixed-point pumps and non-fixed-point pumps
Extracorporeal pumps and implantable pumps
Mechanical pumps and electronic pumps (push syringe infusion pumps & peristaltic infusion pumps)

9. Development trends
The functions will be more comprehensive: It can not only administer drugs intravenously, but also deliver blood, enteral nutrition solutions, etc.;
Consumables will be cheaper: There is no need to use a dedicated pressure infusion set as a consumable, and ordinary gravity infusion sets will be more convenient and cheaper;
Safety issues will be more prominent: The use of ordinary gravity infusion sets is prone to consumable confusion, and the resulting accuracy errors and other risks are extremely high;
The scope of use will be wider: After solving the cheapness and safety of consumables at the same time, all bedside infusions will use infusion pumps, and the usage will explode;
Supervision will be stricter: With the increase in the number of uses and the diversification of consumables, a large number of medical accidents and medical risks will occur during the use of infusion pumps, and relevant national agencies will face a more severe regulatory situation, and regulations and measures will be more stringent.

In general, the infusion pump is an important device widely used in the medical field. It ensures that patients receive safe and effective treatment by accurately controlling the infusion rate and flow rate.