NEGATIVE AIR PRESSURE SYSTEM
WITH BURNING UNIT FOR THE CONTROL AND MANAGEMENT OF AIR-BORNE INFECTION
Almed Equipments has developed a specialized modular Operation theatre which satisfies the unprecedented demand for solution to avoid nosocomial infection. This system is central to create safe healthcare environment. It is made keeping in mind the need of proper use of positive air pressure and negative air pressure inside the operation theatre. In principle, a positive pressure operating theatre with adequate air changes could quickly eliminate the virus from the environment, and it has been shown that the risk of cross-contamination from airborne infection is low if the staff is adequately protected with appropriate personal protective equipment (PPE). However, a negative pressure operating theatre offers optimal protection to personnel working in adjacent areas. Hence use of both positive pressure systems and negative pressure systems at the same time to establish an area safe and secure enough to treat patients is necessary. In this system positive pressure is generated through air handling unit which provides fresh and temperature regulated air inside the OT whereas the negative pressure is provided through Laminar air flow system that absorbs the infected air from the operating table using negative air pressure system and further is passed through ultrasonic burning unit that generates heat between 80-85 degree Celsius, thus deactivating biological burden.
This is a guaranteed system and has been tested in NABL accredited SRL laboratory. It proves to be the best solution as it bestows complete solution with Air handling unit and Laminar air flow. system. This system can be used even after the pandemic is over as it maintains proper air cycle and class II quality of air as per instructions given by NABH. More seriously, improper control of hospital Indoor Air Quality may cause hospital-acquired (nosocomial) infections and occupational diseases. It is recommended to use both positive and negative pressure systems in such a manner that it reduces the chances of infection. The positive pressure system is required to complete the need for fresh air inside the OT whereas the negative system helps to maintain the cycle of the oneway flow pattern of air and secured environment to treat patients.
The negative pressure room works on the principle of creating pressure lower than that of surroundings to allow air to flow into the room but not to escape from the room, as air will naturally flow from areas with higher pressure to areas with lower pressure, thereby preventing contaminated air from escaping the room. To create this negative pressure inside the room a backward curved fan (BCF) of 400 Diameter, which has the velocity of 1500 cubic feet per minute (CFM), A miniplate HEPA filter of 0.1
micron which has a nano-particle coating of Ethanol, Hydrogen peroxide, Silver nitrate, Sodium Hypochlorite, and Keratin is used. Silver nitrate has bactericidal and virucidal property and keratin helps to clear VOC (volatile organic chemical) that is used to remove the unwanted smell from the experimented room and absorbs gases. This type of
HEPA filter has an ability to trap the virus and deactivate it with the use of chemical coating on it. Finally, an ultrasonic ceramic heater, which has the capacity to heat from 900 to 1000 degree Celsius and is controlled using an air rating controller to maintain the temperature between 80 to 85 degrees, in this temperature it is observed that the virus is destroyed. Thus, it fulfills the requirement of disinfecting air and creating a safe indoor air quality for the healthcare facility.
The positive pressure room works on the principle of maintaining a higher pressure inside the treated area than that of the surrounding environment. This means air can leave the room without circulating back in. In this way, any airborne particle that originated in the room will be filtered out. In healthcare facilities, a positive pressure room acts as a protective environment that allows staff to keep vulnerable patients safe from infectious disease. A proper operation theatre with good quality of indoor air quality plays a major role in avoiding the chances of spreading of this post-operative infection. Windows and split air conditioners are major pockets of microbial growth, hence they are not suggested in intense care units or operation theatres, central air conditioners are one of the options but it requires 24 hours of AHU blowers to avoid stagnant air inside operation theatre hence it adds up to operating cost and thus is also not powerefficient plus AHU of each operation theatre should be dedicated and should not be linked to another service area as that may lead to Nosocomial infection. To Obtain perfect condition inside the Operation theatre factors such as air changes per hour, Air Velocity, positive pressure inside the room, temperature, and relative humidity must be taken into consideration. There must be at least 20 air changes per hour in the room, air velocity must be unidirectional and on the table, air velocity should be 2535 FPM (feet per minute) which could be obtained using a laminar airflow system, minimum positive pressure recommended is 2.5 Pascal (0.01 inches of water) and humidity 55% for 18-27 degree Celsius temperature. The display includes Actual Temperature Display with control, Humidity (Rh) Display with control, Pressure of Air Flow from HEPA Filter, Air Cycle Per Hour (ACH) which helps to know whether the room has enough air cycles and is ready for operation, Gas Sensor detecting CO2 which helps the fresh air damper to open and occupy desired air Quality, Air Particle Quality, HEPA Filter working status, Positive Pressure (Pascal) inside the room. This helps to know whether the desired environment is maintained in the room. In this system, the positive pressure system helps to absorb fresh air from the environment. Thus, it acts as an essential unit to generate air cycles in the room. Hence, this system provides good air quality and creates class II (particle count less than 100) quality of air which is measured through a particle count device. It has two types of filter prefilter and HEPA filter of 0.1 microns which helps to block all kinds of virus, bacteria, and a negative ion generator to deactivate pathogens.
The negative and positive pressure system works together to create a oneway ventilation system which according to ASHRAE guidelines is necessary for rooms in which COVID-19 patients are treated. The positive pressure air system takes the fresh air from the environment into the room, the fresh air is prefiltered in the system using a HEPA filter which has a filter size of 0.1 Micron, after filtration from the HEPA filter 100% fresh air is released in the experimented room. This way the patients in the room will get fresh air and since this is a oneway ventilation system the patients in the room are always assured to have good Indoor air quality. This air is then passed through the negative pressure system which destroys the VOC, filters, and burns the virus with the help of an ultrasonic ceramic heater this reduces the biological burden that means the air before leaving the room is stripped off from all the virus, bacteria, etc. This makes our system more suitable to use.