The development of medical protective clothing

 Generally speaking, there are two main ways to protect medical staff in the process of treating patients. The first is vaccination and the second is personal protection. However, it takes a long time for an infectious disease to be promoted to the market from the emergence to the development of corresponding vaccines, and it cannot adapt to the outbreak at all. Therefore, personal protection is the most timely and appropriate way. Medical protective clothing is the most important part of personal protective equipment for medical personnel. It can cut off the transmission route of COVID-19 virus, prevent the spread and transmission of the virus, and control cross-infection in medical institutions. It is of great significance to protect the health and life safety of medical workers. At the same time, during the epidemic, a large number of personnel in epidemic prevention, medical waste disposal and other work are needed to ensure the orderly and smooth implementation of the prevention and control work, and these personnel also need necessary protection during their work.

The development history, production process, raw materials and usage of protective coveralls are summarized and introduced, and the development direction of medical protective gown is further pointed out, providing guidance and reference for medical protective clothes manufacturers, use and standard formulation units and public medical supplies reserve departments.

1 The transmission process of the virus

Novel Coronavirus is a respiratory infection virus with a diameter of 60-140 nm. It cannot exist on its own but must attach to something, such as droplets, particulate matter, etc. At present, the main transmission routes in the world are contact transmission, droplet transmission, aerosol and feces transmission. The nucleic acid of the virus was detected in throat swabs, blood and urine of patients with mild symptoms, but it is difficult to detect in blood and urine, while it can be detected in all patients with severe symptoms. Therefore, for a large number of patients with early mild symptoms, the virus is mainly transmitted by droplets. In daily life, the respiratory organs of the human body, such as the mouth and nose, will carry out physiological activities such as breathing, sneezing, spitting, talking, and runny nose. These behaviors will produce liquid substances, which become carriers of viruses, and may be attached to the human body or other substances indirectly touch the human body. For human beings, communication is inevitable. Especially when doctors and patients are in close contact with each other, the vibration of vocal cords drives liquid small molecules to spread from the mouth to the air. These substances, which are almost invisible to the naked eye, are easy to directly or indirectly contact the skin and oral mucosa of close contacts, resulting in disease. Studies have shown that hot water treatment at 56 ℃ for 30 min, chloroform, peracetic acid 75% ethanol and chlorine-containing disinfectant can inactivate novel coronavirus, which has an important guiding role in daily epidemic prevention and control.

Development of medical protective coveralls

Medical protective gown is a general term. It can be divided into four types according to different application scenarios and requirements: daily clothing for identification, surgical gown, isolation gown for blocking common infections, and protective clothing for isolating high infection risks. Due to the particularity of its use environment, medical protective clothing is mostly used in the department of infectious diseases, but rarely used in daily life. Therefore, the academic and business circles focus more on the research and development of surgical gowns, surgical drapes and other commonly used protective materials, while medical protective gown usually pays little attention to. This article will focus on medical protective suit for virus protection.

2.1 Early medical protective coveralls

The early surgical cure rate was very low. In 1867, Joseph , a Victorian British surgeon, first proposed that post-operative infection was caused by external factors, and then the surgical cure rate gradually improved. The material of early medical protective gown is generally made of natural cotton fiber, which ensures its comfort. However, cotton fiber is easy to absorb water, which brings a disadvantage. It has a certain blocking effect in dry conditions, but once it is soaked, it will lose its blocking effect, which will bring danger to patients. Therefore, it is necessary to improve the barrier of medical protective clothing to protect patients. In 1952, William et al. first proposed that medical clothing should have the effect of preventing liquid from entering, but all kinds of materials on the market could not achieve perfect unity in isolation and air permeability. In 1969, GORE made microporous breathable membranes from PTFE resin and lubricants. They were excellent waterproof and breathable materials, providing both isolation and air permeability. However, PTFE microporous breathable membranes were expensive, so they were used in small quantities on the market. In 1977, Goldman put forward the "4F" principle for functional clothing, namely fashion, fit, feel and function. Since then, medical protective clothes has basically followed the development of this concept. But at this point, medical protective clothing refers more to surgical clothing.

2.2 Modern medical protective coveralls

After the 1980s, with the development of science and technology and the deepening understanding of various infectious diseases and infections, medical protective clothing attracted the attention of all countries. Medical protective gown has been expanded from surgical gown to surgical clothing, supplemented by non-surgical protective clothes, from the safety of patients as the starting point to the comprehensive consideration of patients and medical staff safety. At the same time, the development of nonwoven materials and membrane products more cater to the market, providing a basis for the development of medical protective clothing. In terms of standard formulation, the United States took the lead in formulating standards related to surgical clothes and laying sheets in 1991, followed by the European Union in implementing the Guidelines for Medical Devices in 1998. Foreign medical protective clothing research is becoming more perfect. For example, Biowear material developed by DuPont can protect against pathogens carried in blood, and Bactekiller from Japan has sustained antibacterial effect. Aire Group in the UK makes TyvekF/microporous membrane/TST protective suits for civilian reuse. While improving the protective performance, more attention should be paid to the psychological and physiological conditions of medical staff wearing protective clothing. This is because wearing medical protective clothing has been found to increase the likelihood of thermal fatigue, reduce executive ability by 16% to 34%, and require greater effort to administer iv and ventilation assistance to patients.