Intelligent medical infusion pumps and their applications
I. Introduction
With the development of science and technology, more and more fields need to accurately control the flow rate or flow rate of fluids, such as the chemical field of trace chemical elements in the detection and analysis of the flow rate often need to be precisely controlled. The flow rate of medicinal fluids in the healthcare field is also sometimes precisely controlled.
Intravenous infusion is one of the most commonly used clinical treatments, and is a common delivery technique in the nursing profession. Clinically, the appropriate infusion rate should be dispensed depending on the drug and the patient's condition. Infusion too fast, may lead to poisoning, the more serious will lead to edema and heart failure;
Infusion is too slow may occur in the amount of medicine is not enough or unnecessarily prolong the infusion time, so that the treatment is affected and to the patient and nursing work to increase the burden of unnecessary. Conventional clinical infusion, commonly used hanging bottle infusion, and eye observation, relying on manual clamp to control the speed of drug drops, is not easy to accurately control the speed of infusion, and the workload is large.
Chemotherapy for cancer patients and rescue treatment for critically ill patients requires that the drugs be infused at a constant rate, and that the chemotherapeutic drugs be infused uniformly and continuously by adjusting the speed and time of the input to achieve the optimal effect of chemotherapy and to minimize the side effects of the chemotherapeutic drugs.
Diabetics suffer from the disease and need to be given a certain amount of insulin at a certain rate. In the past, the practice was basically to inject a large dose of insulin at a time, which not only resulted in a huge waste, but also a shorter duration of the drug's effect, so there is a great need for a continuous delivery device with controlled flow rate and velocity to deliver a small amount of the drug and accurately control its delivery speed and flow rate.
For the elderly, children and the physically weak to deliver some special drugs, such as anesthetics, antihypertensive drugs nitroprusside, TPN (pyridine triphosphate nucleotide), etc., the infusion speed and dosage especially need to be carefully and accurately controlled, or there will be serious consequences.
Blood coagulates very easily, and it is easy to block the infusion tube during transfusion. It is important to ensure that the blood flow rate is greater than a certain value in order to have a smooth transfusion.
In addition, no matter whether it is infusion or blood transfusion, ordinary infusion set can not be automatically alarmed for occasional malfunctions, such as air bubbles, blockage, etc., during the completion of infusion and infusion process, and can not cut off the infusion pathway in time, which will have adverse consequences. It should be handled in time to avoid blood backflow or other consequences.
Therefore there is a need for intelligent infusion pumps to control the delivery of medicinal fluids with abnormal alarms.
Two, intelligent infusion pump function
Intelligent medical infusion pump can meet the needs of a variety of functions, summarized, the infusion pump can achieve the following functions:
(1) can accurately measure and control the infusion rate;
(2) can be accurately measured and control the volume of infusion;
(3) liquid flow linearity is good, does not produce pulsation;
(4) liquid flow is good, does not produce pulsation;
(5) can be used to control the delivery of the infusion rate;
(6) the infusion pump is a good solution for the treatment of the blood. p>
(4) Alarm for abnormalities such as air bubbles, empty fluid, leakage, abnormal heart rate and blockage of infusion tube, and automatically cut off the infusion path;
(5) Realize intelligent control of infusion.
Three, intelligent medical infusion pump system structure
Intelligent infusion pump system is mainly composed of the following parts:
Microcomputer system, pump device, detection device, alarm device and input and display device. Figure 1 is the intelligent infusion pump system structure block diagram.
1. microcomputer system: the whole system is the "brain", the whole system for intelligent control and management, and processing of detection signals, generally using a single-chip system.
2. pump device: is the whole system of the "heart", is the transmission of liquid power source. At present, there are many kinds of pump devices, in the back of the detailed description.
3. Detection devices:
Mainly a variety of sensors, such as infrared droplet sensors (responsible for the detection of liquid flow rate and flow), pressure sensors (responsible for the detection of clogging and leakage) and ultrasonic sensors (responsible for the detection of air bubbles), etc., which can sense the corresponding signals, which are amplified and processed, and then sent to the microcomputer system for signal processing and control instructions, and then carry out the corresponding signals, which are amplified and processed, sent to the microcomputer system for signal processing, and then the control instructions. control instructions, and then carry out the corresponding control operations.
4. Alarm device:
Sensor sensed signals processed by the microcomputer, resulting in alarm control signals, and then by the alarm device response to draw attention to the same time for the correct processing. There are mainly photoelectric alarm (light-emitting diode) and sound alarm (speaker and buzzer) and so on.
5. Input and display device:
The input part is responsible for setting the parameters of the infusion, such as the infusion volume and infusion rate. The display part is responsible for displaying the parameters and the current working status, etc., mostly using LED digital tube display and LCE liquid crystal display.
Four, the pump device
Pump device is a lot of kinds of classification is also diverse, on the driving principle can be divided into electromagnetic pumps, pneumatic pumps and piezoelectric pumps, etc.;
On the structure of centrifugal impeller pumps, gear pumps and peristaltic pumps, etc.. Medical infusion pumps need to accurately control the flow of liquid and flow rate, some types of pumps is difficult to do this, and taking into account the infusion tube to be installed easily, the liquid can not be contaminated with the pump device and other factors, so the most widely used are the following:
1. Finger-like peristaltic pump
Currently widely used is the finger-shaped peristaltic pump (Finger-like), the peristaltic pump, the peristaltic pump, the peristaltic pump, the peristaltic pump, the peristaltic pump, the peristaltic pump, the peristaltic pump and the peristaltic pump. Peristaltic Pump), also known as linear peristaltic pump (Linear
Peristaltic
Pump), it is small, lightweight, accurate dosing, easy to use, easy to install the infusion tube. As shown in Figure 2, this pump has a camshaft, the camshaft has more than one (generally 12) cams, the cams of the law of motion difference of a certain angle, each cam with a "finger" (i.e., slider) connected. At work, driven by a stepper motor camshaft rotation, so that the slider in accordance with a certain order and the law of motion up and down reciprocating motion, like a wave like sequential extrusion of intravenous tubing, so that the liquid in the tubing to a certain speed of directional flow. This kind of pump is more precise and easy to control. Pulsation is not desired during infusion and requires good pump linearity. Pump linearity and the number of "fingers" related to the number of "fingers" when the number of "fingers" more than 8, there is a very clear linearity, pulsation is also significantly reduced.
2. Disc peristaltic pump
This peristaltic pump has a circular inner circumference of the pump casing, there is a center wheel, the edge of the center wheel is axisymmetric distribution of a certain number of rotatable extrusion wheel installed, the pipeline clamped between the extrusion wheel and the pump casing of the circular inner circumference. At work, the stepper motor drives the center wheel rotation, the center wheel and drive its surrounding extrusion wheel rotation, the center wheel like a "star", extrusion wheel like a "planet", extrusion wheel both around the center wheel rotation, but also around their own axis rotation. Several extrusion wheel along the center wheel sequence extrusion tube, so that the liquid flow in a certain direction. As shown in Figure 3.
3. Syringe pump
This pump consists of a stepper motor and its driver, a silk rod and bracket, etc., with a reciprocating movement of the silk rod, the nut, and therefore also known as the silk rod pump. The nut is connected to the piston of the syringe, which holds the medicine. When working, the microcontroller system sends out control pulses to make the stepper motor rotate, and the stepper motor drives the silk rod to turn the rotary motion into a linear motion, pushing the piston of the syringe for injection and infusion, and inputting the medicinal liquid in the syringe into the human body. The schematic diagram is shown in Figure 4.
4. Elastic Infusion Pump
This kind of infusion pump relies on mechanical force, which consists of balloon container, infusion tube and infusion regulator, as shown in Figure 5. Balloon container that is the pump body, its inner membrane is synthetic elastic rubber (not latex). When working, the first syringe into the pump body into the liquid, and then make the pump body seal, so that the pump body has a positive pressure, open the infusion regulator, the use of synthetic rubber elasticity of the extrusion effect, you can be continuous or intermittent liquid into the body. This pump can be carried around, easy to use, mostly used for long or intermittent infusion.
V. Product introduction and development trend
Now there are a variety of infusion pumps on the market, according to different standards have different classifications:
Fixed-point pumps (Stationary) and non-fixed-point pumps (Ambulatory);
Standard and portable pumps ( Portable); External and Implantable;
Mechanical, Electronic and Gravity;
Volumetric and Peristaltic. Peristaltic), as shown in Figure 6. Fixed pumps have precise control and complete alarms, but are large;
Portable pumps are small enough for the patient to carry around, use batteries as a power source, and are only suitable for small-volume infusions;
Implantable pumps are easy to use, and patient movement does not interfere with the infusion, but they require surgical intervention;
Mechanical pumps deliver medications and fluids with positive pressure, have no power source (batteries or AC power), are small, and can be operated by a peristaltic pump (Peristaltic). ), small size, portable, mainly used for conveying small volume, long time or intermittent infusion, usually used for chemical medicine, pain or antibiotic type of infusion;
Electronic pump infusion speed up to 999mL/h, can realize intelligent control.
Foreign development of intelligent infusion pumps earlier, such as Japan, the United States and Germany and other countries in the late 1980s on the development of infusion pumps. Most of the popular on the market now are foreign products, a variety of types, better performance, such as Japan's JMS Corporation's OT-601 infusion pump (control accuracy of 10%) and SP-500 syringe pumps, the U.S. IMED Gemini
PC-2TX type infusion pumps can be realized in the four-channel control, as well as Germany's Beltran (B|BRAUN) company's Multifuse type, Perfusor
Compact type (control accuracy can be up to 2%), Infusomat P type and Infusomat
fmS type, a large number of models, and Israel also has a corresponding product.
Domestic development of infusion pumps started late, mostly in the mid-1990s began to study, there are some domestic infusion pumps on the market, such as the Beijing Keli Feng high-tech development limited liability company's ZNB series of products, Shenzhen Comfort Company also has infusion pump products. But in general, less variety, performance needs to be improved.
Infusion pumps will be more miniaturized, more portable, more accurate control, more safe and reliable development. Insulin pumps for diabetes treatment, for example, can now be carried around without interfering with most of your daily life, and you can even take the pump with you in the shower or for a swim, such as MiniMed's Model 507.
Infusion pumps are also developing in the direction of greater intelligence. For example, a continuous glucose-measuring system will later be implanted under the skin of diabetics, which includes a small sensor that detects subcutaneous body fluids at regular intervals and obtains blood glucose data. When the blood sugar is too high, the system will sound an alarm. The insulin pump measures the diabetic's blood glucose level according to the glucose sensor, and then automatically controls the pump to inject insulin into the patient's body, truly realizing intelligent delivery.
Sixth, Conclusion
Intelligent medical infusion pumps can accurately control the flow rate and flow rate of the delivered medicinal solution, and can alarm the abnormalities during the infusion process, as well as timely and automatic removal of the infusion pathway. The application of intelligent infusion pump helps to reduce the intensity of medical and nursing work, improve safety, accuracy and work efficiency, and improve the level of nursing care. Infusion pumps can be widely used in internal medicine, surgery, pediatrics, cardiovascular, emergency department and operating room, especially for infusion therapy in ICU and CCU wards.
In the field of healthcare, for the precise control of the flow rate and flow of medication, intelligent infusion pumps will have a wide range of development prospects, and she will become a magnificent flower in the precise infusion.