Application of laser microporous films in the medical industry

The use of thin films can be seen everywhere in medical places, such as filter membranes on liquid pipelines, breathable membranes on urine bags to balance internal and external pressures, gas exchange membranes in artificial heart-lung machines, dialysis membranes used in dialysis, barrier membrane nets to repair atrial defects, and anti-adhesive membranes to prevent intestinal adhesion after abdominal surgery. In order to achieve the purpose of use, these medical films not only have different specifications of membrane pore sizes and mechanical strength, but more importantly, they are non-toxic, easy to sterilize, and the materials cannot cause allergic and inflammatory reactions. When the film needs to achieve ventilated and watertight holes, the laser process here is particularly important. In traditional mechanical punching holes, even if there are cracks on the edges of the holes, it is easy to stretch the film during use, causing tearing.

The scope of medical membranes is very wide and can be roughly divided into three categories: in vitro use, blood contact and in vivo placement. The following are possible applications and the special requirements required.

For in vitro use:

Since this film does not come into direct contact with the patient's body tissue or body fluid, it does not pay attention to the so-called tissue or blood adaptability, but it still needs to meet the requirements of sterility and non-toxicity. Therefore, due to the different surface intimacy and hydrophobicity of its materials, it is divided into ventilated and impermeable membranes and intravenous injection membranes.

Ventilated and impermeable membrane

In order to balance the pressure inside and outside the container, medical supplies must use a ventilated but impermeable film. For example, when dripping, the pressure in the bottle will continue to decrease as the liquid is continuously injected into the body. If there is no external gas injection, the dripping water in the bottle will not be able to drip out due to the low pressure. Therefore, nursing staff often insert a needle with a ventilated but impermeable film into the rubber at the bottom of the bottle, so that external gas can enter the bottle, but the liquid in the bottle will not leak. Since the external gas may contain bacteria, the film must be able to prevent microbial invasion, and the size of the pores on the film must be controlled at about 0.2 microns. In addition, in order to meet the requirements of ventilation but impermeability, most of these films use hydrophobic materials such as polypropylene or Teflon. In order to ensure sterility and non-toxicity, the solvents and plastic agents used in the production process must not remain, and disinfection should be true. Just be careful not to change the biological or chemical properties of the film.

Films for similar purposes can also be found on urine bags, artificial anuses, and surgical pumps. The difference is that the film of this device is designed to prevent body fluids from escaping and contaminating during the exhaust process, but its production requirements and specifications are similar to those of the above applications.

Filter membrane for intravenous injection

The most common membrane used for extracorporeal fluid filtration is drip infusion, especially the filter membrane on the pipeline during blood transfusion. This filter membrane is the last line of defense for foreign fluids to enter the human body, and is used to block insoluble particles that may be contained in the injected drugs or polymers produced during blood transportation and storage. This membrane must allow liquid to pass easily, so hydrophilic polymer membranes are often used, and the commonly used materials are mainly nylon. The membrane pores for drug injection are about 15 microns, and the blood transfusion membrane can reach about 200 microns!

One of the special membranes is the membrane used to inject platelets into patients. When patients cannot make enough platelets due to blood diseases or chemotherapy, external platelet supplementation is required. Fresh blood donations are separated into three layers of red blood cells, platelets and plasma proteins after centrifugation. The platelet portion is removed and collected into a bag and then injected into the patient. However, the platelets provided by a single platelet donor are usually not enough for a transfusion. They need to collect blood bags from multiple people to get enough platelets. Since platelets are the main part, it will cause a strong reaction of the immune system, so medical staff usually use platelet filters for filtering. The filter membrane pores of this filter are about 5 microns. This size allows platelets to pass through, but blocks white blood cells. It is particularly important that the surface of the membrane still needs special treatment to avoid platelet activation causing thrombotic reactions.

Therefore, Laser punching membranes are widely used in the medical industry. Huayue Laser has unique advantages in film punching and front and back ends. From the increase in hole density to the speed of the equipment, it has continuously broken the monopoly of foreign countries in this technology and achieved diversified innovation.