Intelligent medical infusion pump and its application

I. Introduction

With the development of science and technology, more and more fields need to accurately control the flow or speed of fluid, such as the detection and analysis of trace chemical elements in the chemical field. In the medical field, it is sometimes necessary to accurately control the flow and speed of liquid drugs.

Intravenous infusion is one of the most commonly used treatment methods in clinic, and it is also a commonly used medication treatment technology in nursing specialty. Clinically, the appropriate infusion speed should be matched according to the different conditions of drugs and patients. Too fast infusion may lead to poisoning, and in more serious cases, edema and heart failure may occur;

If the infusion is too slow, it may lead to insufficient dose or unnecessary extension of infusion time, which will affect the treatment and increase the unnecessary burden on patients and nursing work. Conventional clinical infusion generally adopts infusion by hanging bottles and visual inspection, and relies on manual clips to control the dropping speed of drugs, which is difficult to accurately control the infusion speed and has a large workload.

Chemotherapy for cancer patients and rescue treatment for critically ill patients all require uniform infusion of drugs. By adjusting the input speed and time, chemotherapy drugs can be injected evenly and continuously, which can not only achieve the best effect of chemotherapy, but also minimize the side effects of chemotherapy drugs.

People with diabetes need to inject a certain amount of insulin at a certain speed when they get sick. In the past, large doses of insulin were basically injected at one time, which not only wasted a lot, but also took effect for a short time. Therefore, there is an urgent need for a continuous drug delivery device with controllable flow rate and flow rate to deliver a small amount of drugs and accurately control its delivery speed and flow rate.

When delivering some special drugs to the elderly, children and the infirm, such as anesthetics and antihypertensive drugs such as sodium nitroprusside and TPN, it is especially necessary to carefully and accurately control the infusion speed and dosage, otherwise it will cause serious consequences.

Blood is very easy to coagulate, and it is easy to block the infusion tube during blood transfusion. Ensure that the blood flow velocity is greater than a certain value, and blood transfusion can be carried out smoothly.

In addition, no matter whether it is transfusion or blood transfusion, ordinary infusion devices can't automatically give an alarm for unexpected failures such as bubbles and blockage after and during transfusion, and can't cut off the infusion channel in time, which will have adverse consequences. It should be handled in time to avoid blood backflow or other consequences.

Therefore, it is necessary to use intelligent infusion pump to control the delivery of liquid medicine and give an abnormal alarm.

Second, the function of intelligent infusion pump

Intelligent medical infusion pump can meet the needs of multiple functions. To sum up, the infusion pump can achieve the following functions:

(1) can accurately measure and control the infusion speed;

(2) The infusion volume can be accurately measured and controlled;

(3) The liquid flow has good linearity and no pulsation;

(4) It can give an alarm for air bubbles, empty liquid, liquid leakage, abnormal heart rate, blocked infusion tube and other abnormal situations, and automatically cut off the infusion channel;

(5) Intelligent control of infusion is realized.

Third, the system structure of intelligent medical infusion pump

The intelligent infusion pump system is mainly composed of the following parts:

Microcomputer system, pump device, detection device, alarm device and input display device. Figure 1 is the system structure block diagram of intelligent infusion pump.

1. Microcomputer system: It is the "brain" of the whole system, which intelligently controls and manages the whole system and processes the detection signals. Generally, single chip microcomputer system is adopted.

2. Pump device: it is the "heart" of the whole system and the power source for conveying liquid. There are many kinds of pump devices at present, which will be introduced in detail later.

3. Testing equipment:

Mainly various sensors, such as infrared droplet number sensor (responsible for detecting liquid speed and flow), pressure sensor (responsible for detecting blockage and leakage), ultrasonic sensor (responsible for detecting bubbles) and so on. , can sense the corresponding signal, after amplification, send it to the microcomputer system for signal processing, get control instructions, and then carry out corresponding control operations.

4. Alarm device:

After the signal sensed by the sensor is processed by the microcomputer, the alarm control signal is obtained, and then the alarm device reacts to attract people's attention and handle it correctly. There are mainly photoelectric alarms (light emitting diodes) and sound alarms (speakers and buzzers).

5. Input and display equipment:

The input part is responsible for setting various parameters of infusion, such as infusion volume and infusion speed. The display part is responsible for displaying various parameters and current working status. LED digital tube display and LCE liquid crystal display are mostly used.

Fourth, the pump device.

There are many kinds and classifications of pump devices, which can be divided into electromagnetic pump, pneumatic pump and piezoelectric pump according to the driving principle.

Structurally, there are centrifugal impeller pump, gear pump and peristaltic pump. Medical infusion pump needs to accurately control the flow rate and velocity of liquid, which is difficult for some types of pumps. In addition, the following types are mainly adopted, considering the factors such as convenient installation of infusion tubes and the fact that the liquid will not pollute the pump device:

1. Finger peristaltic pump

At present, finger peristaltic pump is widely used, also known as linear peristaltic pump.

Peristaltic

Pump), small size, light weight, accurate quantification, convenient use and easy installation of infusion tubes. As shown in Figure 2, this pump has a camshaft with many cams (generally 12). The laws of motion of these cams differ by a certain angle, and each cam is connected with a "finger" (that is, a slider). When working, the stepping motor drives the camshaft to rotate, so that the slider moves up and down according to a certain sequence and motion law, and sequentially squeezes the intravenous infusion tube like a wave, so that the liquid in the infusion tube flows directionally at a certain speed. This kind of pump is accurate and easy to control. Pulsation is undesirable during infusion, and the linearity of the pump is required. The linearity of the pump is related to the number of "fingers". When the number of "fingers" exceeds 8, there is obvious linearity and the pulsation is obviously reduced.

2. Disc peristaltic pump

The peristaltic pump has a pump shell with an arc inner circumferential surface and a central wheel, and a certain number of rotatable extrusion wheels are installed on the edge of the central wheel in an axisymmetric distribution, and the infusion tube is clamped between the extrusion wheels and the arc inner circumferential surface of the pump shell. When working, the stepping motor drives the central wheel to rotate, and then drives the extrusion wheels around it to rotate. The central wheel is like a "star" and the extrusion wheel is like a "planet". The extrusion wheel rotates around the central wheel and also around its own axis. A plurality of extrusion wheels sequentially extrude the infusion tube along the central wheel to make the liquid flow in a certain direction. As shown in figure 3.

3. Jet pump

This pump is composed of stepping motor and its driver, screw and bracket. It has reciprocating screws and nuts, so it is also called screw pump. The nut is connected with the piston of the syringe, and the syringe is filled with liquid medicine. When working, the single-chip microcomputer system sends out control pulses to make the stepping motor rotate, and the stepping motor drives the screw to change the rotating motion into linear motion, pushing the piston of the syringe and injecting the liquid medicine in the syringe into the human body. The schematic diagram is shown in Figure 4.

4. Elastic infusion pump

This infusion pump relies on mechanical force and consists of a balloon-shaped container, an infusion tube and an infusion regulator, as shown in Figure 5. The balloon container is a pump body, and its inner membrane is synthetic elastic rubber (not latex). When working, the syringe is used to inject the liquid medicine into the pump body, then the pump body is sealed to make the pump body have positive pressure, the infusion regulator is opened, and the liquid medicine is continuously or intermittently input into the human body by using the elastic extrusion effect of synthetic rubber. This pump is easy to carry and use, and is often used for long-term or intermittent infusion.

Verb (abbreviation of verb) product introduction and development trend

There are various infusion pumps on the market now, which are classified according to different standards:

Fixed-point pump (fixed) and non-fixed-point pump (mobile);

Standard pumps and portable pumps; External pumps and implantable pumps;

Mechanical pumps, electric pumps and gravity pumps;

Positive displacement pump and peristaltic pump, as shown in Figure 6. The fixed pump has accurate control and complete alarm, but its volume is large;

Portable pump is small in size and can be carried by patients. It uses battery as power supply and is only suitable for a small amount of infusion.

The implantable pump is easy to use, and the patient's movement will not affect the infusion, but surgery is needed;

Mechanical pump uses positive pressure to transport drugs and liquids, without power supply (battery or alternating current), which is small in size and easy to carry. It is mainly used for small volume, long-term or intermittent infusion, and is usually used for chemotherapy, analgesia or anti-drug infusion.

The infusion speed of electronic pump can reach 999mL/h, which can realize intelligent control.

Intelligent infusion pumps developed earlier in foreign countries, such as Japan, the United States and Germany in the late 1980s. At present, most of the popular products on the market are foreign products, with various types and good performance, such as OT-60 1 infusion pump (control accuracy is 10%) and SP-500 injection pump of JMS company in Japan and Gemini of IMED company in the United States.

PC-2TX infusion pump can realize four-way control, and B|BRAUN's Multifuse and infuser are also available.

Compact (control accuracy can reach 2%), Infusomat P type and Infusomat.

There are many models of fmS, and Israel also has corresponding products.

The development of infusion pumps in China started late, and most of them began to be studied in the mid-1990s. There are also some domestic infusion pumps in the market, such as ZNB series products of Beijing Kelifeng High-tech Development Co., Ltd. and infusion pump products of Shenzhen Kangfu Company. But generally speaking, there are fewer types and the performance needs to be improved.

The infusion pump will develop in the direction of miniaturization, portability, more accurate control and safer and more reliable. For example, the insulin pump used for diabetes treatment can now be carried around without affecting most of daily life, and you can even take a bath or swim with the pump, such as the 507 product of MiniMed Company.

Infusion pumps are also developing in a more intelligent direction. For example, a continuous blood glucose measurement system will be implanted subcutaneously in diabetic patients in the future. The system includes a small sensor, which can regularly detect subcutaneous body fluids and obtain blood sugar data. When the blood sugar is too high, the system will give an alarm. The insulin pump measures the blood sugar level of diabetic patients according to the blood sugar sensor, and then automatically controls the pump to inject insulin into the patient's body to realize intelligent drug delivery.

Conclusion of intransitive verbs

The invention can accurately control the flow rate and velocity of the delivered liquid medicine, give an alarm to the abnormal situation in the infusion process, and automatically cut off the infusion channel in time. The application of intelligent infusion pump is helpful to reduce the intensity of medical work, improve safety, accuracy and work efficiency, and improve nursing level. Infusion pumps can be widely used in internal medicine, surgery, pediatrics, cardiovascular department, emergency department, operating room, especially ICU and CCU wards.

In the medical field, intelligent infusion pump will have a broad development prospect for accurately controlling the flow and velocity of liquid medicine, and it will become a magnificent flower in precise infusion.