The Principle Of Surgical Shadowless Lamp

What is Shadowless Operating Lamp

Surgical shadowless lights are used to illuminate surgical sites to best observe small, low-contrast objects at different depths in incisions and body cavities. Since the operator's head, hands and instruments may cause interference shadows on the surgical site, the surgical shadowless lamp should be designed to eliminate shadows as much as possible and minimize color distortion. In addition, the shadowless lamp must be able to work continuously for a long time without emitting excessive heat, because overheating will make the operator uncomfortable and dry the tissue in the surgical field.

Since the first real surgical shadowless lamp came out in 1880, it has been a century of development. During this period, its design process has experienced a long evolution from mirror reflection, light-emitting diodes, hole-type surgical lights, overall reflection shadowless lamps to led surgical shadowless lamps.

In the middle of the 19th century, people created the prototype of the surgical shadowless lamp with the help of mirror reflection.

In the 1850s, the wave of the industrial revolution swept the world, and new things sprung up, including surgical shadow removal technology. At that time, people built the operating room in a southeast facing room with excellent lighting, and opened windows on the roof. The biggest problem at that time was that the operation time had to depend on the sunny day, which was greatly affected by the weather, and the light was easily blocked by the doctor. Subsequently, people began to install mirrors at the four corners of the operating room ceiling, using the mirrors to reflect sunlight to make the operating table more light. Although this method is primitive and ancient, it has become the prototype of the overall reflection surgery shadowless lamp in the future.

At the beginning of the 20th century, surgical lamps using light-emitting diodes as light sources entered the operating room, which became a milestone in the history of the development of surgical shadowless lamps.

The emergence of surgical lights has completely got rid of the dilemma of looking at the sky for surgery, and at the same time, the brightness has also been improved on the basis of natural light sources, but the problem that follows is that the heat radiation of the light-emitting diodes is too high, which may cause lesions There is an inflammatory reaction in the tissue, which also makes the doctor's head overheated. But at that time, the controllability of the shadowless surgical light was relatively weak, and it was inevitable that there would be light deviation and diffuse heat radiation. At the same time, this kind of LED surgical lamp was used until the end of World War II.

With the passage of time, hole-type surgical lamps and overall reflective surgical lamps have come out one after another, which means that the production technology of surgical shadowless lamps has become mature.

What is the sign of a high-quality surgical shadowless lamp is the depth of illumination, the service life of the bulb, the diameter of the light spot, or the camera system. In the final analysis, it is the shadow removal rate it can achieve during clinical operations. At this stage, what the surgical shadowless lamp can do is relatively "shadowless". The surgical shadowless lamp head composed of tens of thousands of integral reflective mirrors, the shadow removal performance in the surgical area is also the most intuitive standard for measuring its quality. . At present, the most widely used operating light in the world is this kind of overall reflective surgical shadowless lamp.

The above are the four golden periods in the development history of surgical shadowless lamps

With the continuous improvement of social productivity and medical device research and development, the future surgical shadowless lamp may come into our eyes with more surprises, and at the same time it will open up new chapters one after another, let us wait and see.

Composition of shadowless lamp

The surgical shadowless lamp is generally composed of a single or multiple lamp heads, which are fixed on the cantilever and can move vertically or circularly. The cantilever is usually connected to a fixed coupler and can rotate around it. The shadowless lamp adopts a sterilizable handle or a sterilizable hoop (curved track) for flexible positioning, and has automatic braking and stop functions to control its positioning, and maintain a suitable space on and around the surgical site. The fixture of the shadowless lamp can be placed on the fixed point on the ceiling or wall, or on the track of the ceiling.

Principle of shadowless lamp

The shadowless lamp is actually not "shadowless", it just lightens the umbra so that the umbra is not obvious. Shadows are formed when light hits an object. Shadows are different everywhere on the earth. If you carefully observe the shadow under the electric light, you will also find that the middle part of the shadow is particularly dark, and the surrounding area is slightly lighter. The particularly dark part in the middle of the shadow is called the umbra, and the dark part around it is called the penumbra. These phenomena are closely related to the linear propagation of light.

If you put a cylindrical tea tube on the table and light a candle next to it, the tea tube will cast a clear shadow. If two candles are lit next to the tea canister, two overlapping but not overlapping shadows will be formed. The part where the two shadows overlap has no light at all and is completely black, which is the umbra; the place next to the umbra where only one candle can be illuminated is the half-shadow penumbra. If three or even four candles are lit, the umbra will gradually shrink, and many layers will appear in the penumbra. This is also the reason why objects 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-mentioned tea cylinder, then the umbra will completely disappear, and the penumbra will be too faint to be seen.

Scientists made a shadowless lamp for surgery based on the above principles. It arranges the lamps with high luminous intensity in a circle on the lamp panel to synthesize a large-area light source. In this way, the light can be irradiated onto 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.

Shadowless lamp installation

Surgical shadowless lamp is an essential lighting facility for surgery in the hospital. In order to align the light to the irradiated area, it is often necessary to use a large force to push up, pull down, and twist, and the force relationship of the lamp is relatively complicated. Therefore, the quality of its installation directly affects the safe use and function of the equipment. How to complete the installation of the shadowless lamp with high quality according to the different architectural structures of the operation, so that it can be used for a long time without structural failure. During installation, it is necessary to coordinate the height and process of the ceiling with the construction personnel of the ceiling to ensure the coordination and beauty of the ceiling and the shadowless lamp, and it is required to leave a maintenance channel on the ceiling.

There are roughly two types of roof structures for operating room buildings:

One is that the roof is cast-in-place concrete, and the installation components of the shadowless lamp have been pre-buried at the specified position, and the safety calculation has been passed (that is, the installation of the shadowless lamp is pre-designed in the building construction drawings). After the situation, if there is no doubt, the installation of the shadowless lamp can be carried out directly.

The other type is that the roof surface is constructed in other forms, such as the roof surface is cast-in-place reinforced concrete, but no pre-embedded installation components, or the roof surface is a prefabricated cement hollow cover plate and other structural types, which are not suitable for direct installation of shadowless lights. This situation is more common in small and medium hospitals.

When installing the shadowless lamp, one or more transformers should be installed in the remote control box on the ceiling or wall to convert the input power supply voltage into the low voltage required by the bulb. Most shadowless lights have dimming controls, and some products can also adjust the light field range to reduce the light around the surgical site (reflections and flashes from bed sheets, gauze or instruments can be uncomfortable to the eyes).

Current status of domestic shadowless lamps

my country's LED medical lighting started around 2007. As the society pays more attention to medical health, medical accidents, environmental protection, energy consumption, etc., LED medical lighting has attracted more and more attention and attention from the society, and the demand is also growing. Many manufacturers have indicated that they will actively develop LED medical lighting products. To replace the current products, LED medical lighting will be the development trend of international medical lighting. It has gradually matured from the initial market exploration. LED surgical shadowless lamps are gradually becoming more and more popular with their gorgeous shapes, long service life, natural cold light effects and energy-saving concepts. Into people's field of vision.