What Is an Infusion Pump?

The infusion pump is usually a mechanical or electronic control device, which controls the infusion speed by acting on the infusion catheter. It is often used in situations where strict control of infusion volume and drug volume is required, such as when using booster drugs, antiarrhythmic drugs, intravenous infusion or intravenous anesthesia in infants. In the following, we should talk about the problems that should be noticed in the daily operation, maintenance and storage of the infusion pump in combination with clinical practical applications.

Chinese name: Infusion Pump
Types of: instrument

Classification of infusion pumps: Peristaltic control type infusion pump
Reason for alarm: AIR flashes with air in the infusion tube

Infusion pump concept

Intravenous infusion is a commonly used method of administration in clinical treatment. The speed of intravenous infusion varies according to the nature of the drug and the patient's physique. If the infusion is too fast or too slow, it is difficult to achieve the desired therapeutic effect and even affect the safety of nursing. At present, the common infusion devices that are widely used in clinical practice mainly rely on the liquid level pressure to input liquid to the recipient, rely on the naked eyes of the nursing staff, and manually adjust the infusion speed to control the infusion speed. Ordinary infusion sets lack the functions of block alarm, bubble alarm, and liquid infusion alarm, which increase the burden of clinical care; 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, ensure that the drug can be uniformly speeded, and that the amount of the drug can be accurately and safely entered into the patient's body to play a role. The speed is not affected by human back pressure and the operator, and the infusion is accurate and reliable, which helps to reduce the intensity of clinical nursing work, improve the accuracy, safety and quality of infusion.

The infusion pumps have various product models and performances. According to its working characteristics, it can be divided into three types: peristaltic controlled infusion pumps, fixed volume controlled infusion pumps and syringe microinjection infusion pumps. ^[1]

System structure and working principle of medical infusion pump

The infusion pump system is mainly composed of a microcomputer system, a pump device, a monitoring device, an alarm device, and an input and display device.

Infusion pump system

The microcomputer system is the "brain" of the entire system. It intelligently controls and manages the entire system and processes the detection signals. Generally, a single-chip microcomputer system is used. For example, the infusion pump uses a highly integrated 32-bit ARMCPU system to fully control the infusion process and uses dual CPUs to ensure the safety of the system.

The pump device is the "heart" of the entire system, and it is a power source for transporting liquids. Medical infusion pumps generally use finger-shaped peristaltic pumps as the power source. Finger-type peristaltic pumps use rollers to rotate a certain part of the infusion pump pipeline, causing peristalsis, thereby pushing the liquid forward. Finger peristaltic pumps are the most widely used due to their small size, light weight, accurate quantification, and easy handling of infusion tubes. This pump has a camshaft, and there are multiple cams on the camshaft. The movement laws of these cams differ by a certain angle, and each cam is connected with a finger slider.

During work, the camshaft is driven by the stepper motor to make the slider reciprocate up and down according to a certain sequence and movement law, and squeeze the intravenous infusion tube in sequence like a wave, so that the liquid in the infusion tube is directed at a certain speed. Finger peristaltic pumps are more accurate and can control the total infusion volume and infusion speed in a wide range. When the number of "fingers" exceeds 8 (generally 12), the linearity of the pump is good, and the infusion pump is less prone to pulsation, which makes the infusion pump The safety and stability monitoring device is mainly composed of a variety of sensors.The infusion pump is equipped with an infrared drop number sensor, a pressure sensor, and an ultrasonic bubble sensor.They are used for liquid flow rate and flow, blocking pressure, and leakage and bubbles. Detection.

The alarm system is that the signal detected by the sensor is processed by a microcomputer to obtain an alarm control signal, which is then responded by the alarm device, which attracts people's attention and performs correct processing at the same time. With photoelectric alarm and audible alarm function, it can alarm the abnormal situation such as power failure, pump door not closed, low temperature, infusion completed, battery under pressure, pipeline blockage, and bubble in the pipeline during the infusion. The input part of the input and display device is responsible for setting various parameters of the infusion, such as infusion volume and infusion speed. The display part is responsible for displaying various parameters and the current working status.

Infusion pump operation

1. Prepare the medicinal solution in the treatment room according to the doctor's order, check the quality, deterioration, discoloration, turbidity, and looseness of the bottle mouth, and the expiration date, saw it open without error, disinfect the Andofo cotton swab, suck the medicinal solution, and perform aseptic operation. Dosing and mixing in principle. Indicate the name, bed number, added drug name, and dose on the bottle sign. Please check with a second person to assist the patient in a comfortable lying position.

2. Adjust the infusion speed and the predetermined infusion volume according to the doctor's order (adjust by 'Select' on the infusion pump panel).

3. Tie the tourniquet, choose the correct blood vessel, loosen the tourniquet, and disinfect the skin with Adolfo, wait for it to dry, prepare the infusion patch, tie the tourniquet, and disinfect the skin again with Adolfo, puncture and fix it properly (same as infusion Operating procedures).

4. Record medication, fluid volume, and infusion speed in the infusion pump

Infusion pump maintenance

To extend the service life of the infusion pump and maintain its infusion stability, please follow the precautions below:

1. Prevent any solid particles from entering the infusion pump body, because dust or any other impurities will wear the plunger, seal ring, cylinder and check valve, so any solid particles in the mobile phase should be removed in advance. The mobile phase is best distilled in a glass container. The commonly used method is filtration. Filters such as Millipore filters (0.2um or 0.45um) can be used. 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.

2. The mobile phase should not contain any corrosive substances, and the mobile phase containing buffer solution should not be kept in the pump, especially when the pump is stopped overnight or for a longer time. If the mobile phase containing the buffer solution is left in the pump, due to evaporation or leakage, or even just because the solution is at rest, tiny crystals of salt may precipitate, and these crystals will damage the seal ring and the plunger, etc., as the solid particles mentioned above. Therefore, pure water must be pumped and washed thoroughly before changing to a solvent suitable for column storage and pump maintenance (for reversed-phase bonded stationary phases, it can be methanol or methanol and water).

3. When the infusion pump is working, pay attention to prevent the mobile phase in the solvent bottle from running out, otherwise the empty pump will also wear the plunger, seal ring or cylinder, and eventually leak.

4. The working pressure of the infusion pump should not exceed the specified maximum pressure, otherwise the high-pressure seal ring will be deformed, causing leakage.

5. The flow box should be degassed first to avoid air bubbles in the pump and affect the stability of the flow. If there are a lot of air bubbles, the pump will not work.

The failure of the infusion pump must be identified and the corresponding measures taken to eliminate the failure:

1. There is no mobile phase flowing out and 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 large flow rate (5ml / min), and the air bubbles can be exhausted. A 50ml syringe can also be used to help the pump outlet. Extract the gas. Another reason may be that the seal ring is worn and needs to be replaced.

2. Pressure flow is unstable. The reason may be air bubbles, which need to be eliminated, or there is a foreign body in the check valve. You can remove the check valve, immerse it in acetone, and perform ultrasonic cleaning. Sometimes it may be that there are air bubbles in the sand filter rod or it is partially blocked by the small crystal particles of salt or the breeding microorganisms. At this time, remove the sand filter rod and immerse it in the mobile phase, remove the bubbles by ultrasound, or immerse the sand filter rod (piece) in Quickly remove microorganisms or dissolve salts in dilute acid (such as 4mol / L nitric acid), and then wash immediately.

3. The reason for the high pressure is that the pipeline is blocked and needs to be cleared or cleaned. The cause of the pressure drop may be a leak in the pipeline. Checking for blockages or leaks can be done step by step.

Infusion pump

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 inserted tightly during use, otherwise it will not work properly. When not in use, put it on the seat on the top of the infusion pump to lock it to avoid damage during storage. When charging, turn off the power switch before charging. If it is used for the first time or after a long period of non-use, fully charge the battery before starting to use it. This infusion pump must not be stored in a place directly blown by cold, humid (hot) air, such as fans, air conditioners, electric stoves, heaters, and humidifiers.

Common failures and treatment methods of infusion pumps

Common alarm display of infusion pump:

1. Bubble alarm

Cause: There are air bubbles in the pipeline, and the liquid in the solution bottle or bag is empty;

Treatment method: open the door of the warehouse, take out the pump tube, discharge the air bubbles, and replace the new infusion bottle;

2. Low battery alarm

Failure reason: the battery / battery power is insufficient, and the battery charging is invalid;

Treatment method: connect AC power and replace the same type of battery;

3.Drop count alarm

Reason for failure: The liquid in the infusion bottle or bag is empty, the flow rate regulator is not opened, the cap is not opened during exhaust, the sensor is placed incorrectly, the sensor is damaged, the drip pot is unstable, there is swing, the drip pot has water mist, and the drip pot liquid Too high

Handling method: replace with a new infusion, open the flow rate regulator, open the exhaust cap, place it properly, clamp the sensor to the drip pot, replace the sensor, fix the infusion pot, keep stable, shake the drip pot to remove water mist, and the liquid level in the drip pot Do not exceed 1/2 of the height of the drip pot, place the infusion bottle upright, and squeeze some liquid back into the bottle to lower the liquid level;

4. Keep open rate

Cause: The liquid in the infusion bottle or bag is empty;

Treatment method: change the infusion or stop the infusion as directed by your doctor;

5, pressure, blocking alarm

Cause of failure: The flow rate regulator (screw clamp) is not loosened, the infusion tube is discounted or compressed; the blood clot blocks the venous access, and the blood pressure at the proximal heart is too high;

Treatment method: loosen the flow rate regulator (screw clamp), release the infusion tube from being discounted or compressed, remove the blood clot, loosen the tourniquet, wear wide cuffs, and avoid measuring blood pressure on the side of the infusion limb;

Infusion pump

Features of infusion pump

The infusion pump can achieve the following functional characteristics: (l) can accurately measure and control the infusion speed; (2) can accurately measure and control the infusion volume; (3) can perform abnormal conditions such as air bubbles, empty liquid, leaking fluid, and blocked infusion tubes Report, and automatically cut off the infusion channel; (4) color OLED display; (5) realize intelligent control of infusion. Product functions cover the basic functions of many products popular in the market, and have certain potential market value. Scope of technology application: Throughout the current lack of exercise resistance, people are susceptible to illness. In the hospital ... (see more) You can often see a lot of people, and now there are many patients who need to slowly press a certain because of special conditions. Drip hourly. If the nurse stares alone, then the workload of the nurse is large and human error is easy to occur. Therefore, a medical instrument that can run and control the drip hourly speed and time according to the wishes of the nurse is needed. In terms of biopharmaceutical development and chemical industry, for example, some liquid drug raw materials must be configured in strict proportions. Now the most common is the test tube dropper configuration. This method of configuring by human eyes has many disadvantages, and the error is large. It is difficult to know the proportion of the ingredients, so an instrument that can accurately measure the output liquid is needed.

Infusion pump type

Fixed-point and non-fixed-point pumps

Extracorporeal and implantable pumps

Mechanical and electronic pumps (injection pumps & peristaltic pumps)

Development Trend of Infusion Pump

1. The function will be more comprehensive: both intravenous administration, blood transfusion, and intestinal nutrient delivery;

2.Consumables will be cheaper: There is no need to use a dedicated pressure infusion set as a consumable, ordinary gravity infusion sets will be more convenient and cheaper;

3.The safety problem is more prominent: the use of ordinary gravity infusion sets is prone to confusion of consumables, and the resulting accuracy errors and other risks are extremely great;

4.The use will be more extensive: After the cheapness and safety of consumables are solved, all bedside infusions will use infusion pumps, and the amount will be blown out;

5 Supervision will be stricter: With the increase in the number of uses and the diversification of consumables, there will be a large number of medical accidents and medical risks during the use of infusion pumps, and the relevant national institutions will face a more severe regulatory situation. More severe.