Vacuum technology in medical applications
June 19, 2020
In most hospital rooms we find a vacuum connection at the wall delivering vacuum pressure for aspiration. Vacuum is a tool in surgery, anaesthesia and during intensive care. The vacuum 'outlets' in patient rooms and surgery rooms are connected to a central vacuum system. These are usually located in the basement floor. They consist of vacuum pump(s), buffer tank, and control. For redundancy and maximised uptime systems have a minimum of two and in most cases three or four vacuum pumps. The pumps are used alternately or started additionally when more pumping speed is required. Most pumps are single stage rotary vane pumps with ultimate pressure around 1 mbar. The buffer vessels have volumes of 100 to 1000 liters, inlet filters and a draining valve for condensed liquids and particles.
The total vacuum system underlies strong medical regulations of quality, certification (e.g. ISO 7396-1) and maintenance. Please note that the pressure measures ''Hg (inch mercury) and cfm are more commonly used that ISO standard pressure units in this application.
The anodes require water-cooling and are often rotated for better heat dissipation. Since the electrons must not be scattered by air molecules it is obvious that all x-ray tubes are evacuated to high vacuum. In general, a pressure of 10-5 to 10-6 mbar is required. Evacuation is done at the tube manufacturer by mid-size turbomolecular pumps backed by rotary vane pumps. The tubes are sealed and by using getter material, a re-evacuation in the hospital is not required.
In this blog we have shown that vacuum technology is present in numerous medical applications and research. Medical vacuum systems are fundamental for delivering vacuum pressure for aspiration and ensuring that both patient rooms and surgery rooms are safe and efficient. Vacuum technology is also pivotal for the sterilisation of medical equipment as well as the use of x-ray tubes in high vacuum conditions.