With the improvement of medical level, the configuration of operating room continues to improve. Shadowless lamp is an indispensable equipment in operating room. The use of shadowless lamp also makes the field of vision of surgery brighter, and can eliminate the influence of shadows on surgery as much as possible.

So what is the working principle of the shadowless lamp?

First, let's talk about the formation of shadows. Shadows are formed when light illuminates an object. The scenes in which shadows are formed are also different, and the effects of shadows in different places are also different. When we look at the shadows under the light, we will also find that the shadows are particularly dark in the middle and slightly lighter around. The dark part in the middle of the shadow is called the umbra, and the dark part around it is called the penumbra. The generation of these phenomena is closely related to the linear propagation of light. If a cylindrical object is placed on a table and a candle is lit next to it, the object will cast a clear shadow on both sides. If two candles are lit next to the object, two overlapping shadows will be formed. The overlapping part of the two shadows has no light at all, and is completely black, which is the umbra; the place where only a candle can shine next to the umbra is the half-light and half-dark penumbra. If three or even four candles are lit, the umbra will gradually shrink and the penumbra will appear many layers. The same is true for objects that can generate shadows composed of umbra and penumbra under electric light. Obviously, the larger the area of the luminous object, the smaller the umbra. If we light a circle of candles around the above object, the umbra disappears completely, and the penumbra fades out of sight. Scientists have made a shadowless lamp for surgery based on the above principles. It arranges the lamps with high luminous intensity into a circle on the lamp panel to synthesize a large-area light source. In this way, light can be irradiated on the operating table from different angles, which not only ensures sufficient brightness of the surgical field of view, but also does not produce obvious umbra, so it is called a shadowless lamp.

What are the components of the shadowless lamp? To put it simply, the surgical shadowless lamp is generally composed of single or multiple lamp heads. The commonly used one is composed of two lamp heads. The lamp head is fixed on the cantilever. The doctor can move vertically or cyclically through the handle of the shadowless lamp. The cantilever is usually connected to the base next to it. On the seat, the cantilever can rotate around it. The shadowless lamp adopts a sterilizable handle or a sterilized hoop (curved rail) for flexible positioning, and has automatic braking and stopping functions to control its positioning, maintaining a suitable space above and around the surgical site. The shadowless lamp handle can also be sterilized by a disposable shadowless lamp handle protective cover, which can avoid cross-infection between operations.

Fixtures for shadowless lamps can be placed on fixed points on the ceiling or wall, or on the ceiling rails.

Five technical requirements for shadowless lamps

1. Brightness requirements

Operating room surgeons must be able to precisely distinguish contours, colors, and movements. As a surgeon, therefore, a light intensity close to sunlight quality is required. 100,000 lux of light is determined to be equivalent to the brightness of the sun at noon. In addition, in the surgical environment, most of the light is absorbed rather than reflected, which means that the surgical shadowless lamp must provide greater brightness. The shadowless lamp can produce a maximum brightness of 150,000lux, and the brightness can be adjusted steplessly. Only at this brightness can the surgeon have 50% of the visible light in the operating area.

2. No heat generation requirement

Bright light is accompanied by heat generation. If heat is generated during the operation, it will bring great harm to the surgeon and the patient. Therefore, what we need during surgery is lighting that has only light and no heat.

3. Pathogen-free requirements

One of the basic elements of surgery is to keep the number of pathogens at a minimum during the operation. Generally, the handle of the shadowless lamp needs to be repeatedly sterilized. After each operation, the handle of the shadowless lamp is removed, and then sent to the disinfection supply room for disinfection. After disinfection, it is installed and used. At the same time, a disposable shadowless lamp protective cover can also be used to avoid pathogen infection.

4. Color temperature requirements

Color perception is determined by the color temperature of the light in which it is placed, for example: the color temperature of sunlight is 5600kelvin; at 5600kelvin, the light perceived by human research is white light. Therefore, experts recommend that the light color temperature in the operating room be at least 4000kelvin; so it can produce the same light as sunlight therapy. For human eyes, the color is only clear in sunlight, which makes the diagnosis more accurate and does not cause the eyestrain of medical staff due to long working hours.

5. No shadow requirement

Through the polygon reflector, the shadowless lamp can meet the requirements of shadowless lighting. Because of its special shape: it consists of many reflective surfaces that reflect light and illuminate the entire surgical area. As a result, many light and shadows are superimposed to form an absolutely homogenous beam of light. The operation is carried out in this light column, that is, the light column formed from 80cm below the lamp plate and reaching the surgical area is carried out. Thanks to the perfect design of the reflective surfaces and the large size of the light-reflecting surfaces, this co-light beam is not only as bright as sunlight but also without shadows. And while the surgeon's shoulders, hands or head block some of the light source, it remains very uniform.

The above is the working principle of the shadowless lamp. Our company can provide a disposable shadowless lamp protective cover, which saves the process of disinfection and sterilization through the supply room, which is convenient for medical staff and reduces the workload.