How does the medical electric device cooling down

         With the rapid development of medical electronics technology, the electronic system cooling is a very important part of medical electronic design. Heat affects the system reliability, performance and its life cycle. To ensure the life and proper operation of electronic devices, the reliable cooling systems need to be designed. Thermal cooling  is one of the most important considerations in medical electronics engineering.

           This article will introduce the common heat dissipation schemes of medical electronic equipment, including natural convection cooling, forced convection cooling, liquid cooling and other forms.

Natural convection cooling:

       Natural convection cooling is a kind of cooling solution for medical electronics equipment, which relies on surrounding air or other media to dissipate heat through natural convection. Compared with traditional forced convection cooling, natural convection has the advantages of low cost, low noise and no need for a power supply.

     The cooling  effect of natural convection cooling mainly depends on the temperature difference between the heat source and its surroundings as well as on the surrounding area, thickness and whether it is blocked or not, thereby forming an airflow on the surface of the device due to the buoyancy induced by the temperature difference. The air flow carries heat away from the surface of the medical electronic device and dissipates to the outside environment.

Forced convection cooling:

       Forced convection cooling is a type of heat dissipation scheme for medical electronic equipment, which utilizes an external power source to artificially drive the air convection, which can enhance the thermal conductivity of the device, thereby increasing the cooling rate.

      Forced convection cooling can be divided into three categories: axial fan cooling, centrifugal fan cooling and cross-flow fan cooling. Each type of fan cooling has its respective advantages and disadvantages that must be taken into account when designing.

       Axial fan cooling is characterized by simple structure, small size and low cost. But it can only move air in a single direction, so air flow is usually not balanced and inefficiency is easy to occur.Centrifugal fan cooling is characterized by high air pressure and high flow rate. But the noise is louder and the shape is bulgy, which is not suitable for the miniaturization of the medical electronic device.Cross-flow fan cooling is characterized by small size, uniform air flow and low noise. But due to its complicated structure, it is difficult to maintain and costly.

Liquid cooling:

     Liquid cooling is a kind of high efficiency cooling solution for medical electronics equipment, which uses liquid as a medium to carry heat away from the device in order to dissipate it.

      The liquid cooling system is usually composed of two parts: the heat transfer and the heat dissipation part. The former is usually made of copper or aluminum for heat transfer and heat exchange; the latter is mainly composed of a radiator and a fan. The radiator's heat dissipation capability is to a large extent dependent on the type of liquid used and the cooling fan's speed.

         For medical electronic equipment, it is very important to design an efficient and reliable cooling system, taking into account the cooling requirements, product cost and environment of the device. Different schemes of heat dissipation have their respective advantages and disadvantages, and should be carefully considered when used. Generally speaking, the thermal solution should be chosen according to the practical application environment, product requirements, cost and other factors.