Principle of surgical led surgical lights
Surgical led surgical 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.
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 denser the light source of the luminous object surrounds the illuminated 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.
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.
The development of surgical shadowless lamp has experienced the development of porous shadowless lamp, single reflection shadowless lamp, porous focus shadowless lamp, LED surgical shadowless lamp and so on.
The picture on the right is a traditional multi-hole shadowless lamp, which mainly achieves the shadowless effect through multiple light sources. The picture on the left shows a single reflection shadowless lamp that is more popular in China, which is characterized by high illuminance and focusability.
More popular in foreign countries is the porous focusing surgical shadowless lamp, which is a higher-end surgical shadowless lamp. In addition, the LED surgical shadowless lamp that is becoming more and more mature has gradually entered people's minds with its gorgeous shape, long service life, natural cold light effect and energy saving concept. in the field of vision.
For shadowless lamps installed on the ceiling, 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 most light bulbs. 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).
1. Daily inspection
- Lamp working status (PRX6000 and 8000). Method: Put a piece of white paper on the working area , if there is an arc-shaped shadow, replace the corresponding light bulb. - Sanitize handles in place. Method: Two "clicks" when installing. - Cleaning: Use a weak alkaline solvent (soapy water) to scrub the exterior; avoid using chlorine-containing lotions (damage to metals) and alcohol-based lotions (damage to plastics and paints).
2. moon moon
Mainly to check whether the backup power system (battery) is normal. Method: Cut off the 220V power supply to see if the backup power supply is activated .
3. lamp life
Halogen lamps , that is, overall reflective surgical shadowless lamps, have an average lifespan of 1,000 hours; more LED surgical shadowless lamps are used , and the bulb life is basically about 60,000 hours. For the lamp holder , it is basically replaced once a year.
4. Annual inspection
Four steps of maintenance (performed by a licensed engineer) - Tighten the power cord connector ( at the input and output of the control box ). Screw brushes at each connection - adjust the rotation limit (for example, 4000 type lamp head around its lamp head arm) bulb operating voltage (23V AC+DC) each joint brake - check the verticality of the suspension tube and the balance of the suspension system at each part of the connection Whether the fastening of the screws is normal Whether the brakes rotate normally when the joints are moving. The effect of heat dissipation. The status of the light bulb. The installation of the disinfection handle .
Operating room surgeons must be able to accurately distinguish contours, colors and movements. As a surgeon, therefore, light intensities close to daylight quality are required . A light of 100,000 lux 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% visible light in the operating field .
No heat production guarantee
When the light is bright, it will be accompanied by heat generation. If there is heat generated during the operation, it will bring great harm to the surgeon and the patient. Therefore, what we need during surgery is lighting with only light but no heat.
Pathogen Free Guarantee
One of the basic elements of surgery is to keep the number of pathogens to a minimum during the operation . Therefore, we adopt the best shape design of the surgical shadowless lamp , with the appropriate placement (behind the surgeon), which can effectively control the number of pathogens.
Color temperature guarantee
Color perception is determined by the color temperature of the light. For example, the color temperature of sunlight is 5600 kelvin; the light perceived by human research under the color temperature of 5600 kelvin is white light. Therefore, experts recommend that the color temperature of light in the operating room should be at least 4000 kelvin; so it can produce the same light as sunlight therapy. For human eyes, the color is only clear in daylight, which makes the diagnosis more accurate and does not make the eyes of medical staff tired from long hours of work.
No Shadow Guarantee
Through the polygonal reflector , the shadowless lamp can meet the requirements of shadowless lighting. This reflection is designed by computer, and it is formed by industrial stamping at one time . The reflectivity is as high as 95%. Its shape is very special: it is composed of many reflective surfaces that reflect light and illuminate the entire operation area . As a result, many light and shadows are superimposed to form an absolutely homogeneous beam of light . The operation is carried out in this beam of light, that is, the beam of light formed from 80cm below the lamp panel and reaching the operation area.
Due to the design of the reflective surface and the large size of the light reflecting surface, this same light column is not only as bright as daylight but also has no shadows. And when the light source is partially blocked by the surgeon's shoulder, hand or head, it can still remain very uniform.