It's because the supplies are expensive, and the supplies are disposable, and you have to use one copy of the supplies to turn it on, so that's why it's said.
The artificial heart-lung machine is an extracorporeal circulatory device that consists of an oxygenator, blood pump, and ancillary equipment. The device draws venous blood from the venous system, oxygenates it outside the body, and then transfers the oxygenated blood back to the arterial system via the blood pump to achieve cardiopulmonary diversion. The device is mainly used for extracorporeal circulation in cardiac surgery, auxiliary respiration in lung transplantation, macrovascular surgery and auxiliary treatment of acute respiratory failure.
During cardiac surgery, the patient's heart and lungs stop working, and the clinic uses an artificial heart (blood pump) and an artificial lung (oxygenator) to replace the work of the normal heart and lungs to maintain the patient and vital signs. Artificial heart-lung machine belongs to Class III medical devices, clinical use, need to use vena cava cannula inserted into the patient's upper and lower vena cava or the right atrium, to draw out the patient's blood.
The patient's blood in the extracorporeal line is regulated by the temperature of the heat exchange tank and flows into the artificial lung to oxygenate the venous blood into arterial blood, which is then pumped into the arterial system by the artificial heart, so that the human tissues and organs can be adequately perfused and the stability of the patient's blood circulation and internal environment can be maintained. In addition to maintaining the patient's vital signs, the artificial heart-lung machine also provides a bloodless operating field for cardiac surgery.
Artificial heart-lung machine mainly includes the following parts:
1. Oxygenator, is an important part of the heart-lung machine, the main function is to carry out gas exchange, so that the blood oxygen contract with the carbon dioxide discharged, temporarily replacing the function of human lungs. High-quality oxygenator should meet the conditions are: blood oxygenation and carbon dioxide discharge ideal, temperature control effect is good, precharge is small, blood damage is small, transmembrane pressure difference is small, easy to operate, easy to exhaust.
2. Blood pump. Artificial heart-lung machine usually has 4~5 blood pumps, each pump has a clear function, in which the main pump is used to replace the ventricular pulsation function, and the rest of the pumps are used for blood reabsorption in the operating field, ventricular decompression and exhaustion, and perfusion of the cardiac arrest fluid during surgery. Within a certain time of extracorporeal circulation, the blood pump should be slightly destructive to the blood, and the console is simple to operate with a backup emergency system.
3. Microthrombus filter. In the extracorporeal circulation, it is inevitable that some solid or gaseous microemboli will be produced, which may block blood vessels and damage tissues and organs, especially the brain and lungs, so blood filters, gas filters, leukocyte filters, and other filters must be used in the process of extracorporeal circulation.
4. Heat-exchange equipment for warming and cooling of the patient's body temperature in extracorporeal circulation and warming of the cardiac arrest fluid.
5. Tubes and cannulas. In extracorporeal circulatory surgery, the appropriate type of tubing and radius of cannulae are selected based on the patient's weight and condition. Tubes and cannulas should have good transparency, elasticity and toughness, smooth inner wall of the tubes, low resistance to blood flow, chemically stable, non-toxic, and have good biocompatibility.
6. Vital signs monitoring device, which can monitor the patient's electrocardiogram, arterial and venous pressures, body temperature, etc. during extracorporeal circulation.
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