What is the purpose of operating lamp?

Correct operating lamp or surgical lighting is essential for patient safety and staff comfort. It should be designed so that the medical team can focus on surgery.In this article, we will learn what the operating lamp is for.

The following knowledge points are listed below:

• The history of the operating lamp

• The purpose of the operating lamp

1. The history of the operating lamp

Before the invention of the electric light, the first operation was performed during the day. The illumination depending on the time of day and the cloud cover. By the end of the 19th century, light bulbs replaced direct sunlight, allowing people to perform operations freely throughout the day.By the 1960s, the use of halogen bulbs increased the amount of light available on the operating table to 100,000 lx, which is equivalent to the bright noon sun on a Mediterranean beach. Thirty years later, the discharge lamp almost doubled the available light to 200,000 lux.But this "more is better" method can cause eye fatigue and reduce the surgeon's work efficiency. Today, more and more surgical lights use LEDs. These bulbs use less energy to produce clearer, cooler lighting, which gives surgeons the visibility they need to make effective diagnostic decisions.

2. The purpose of the operating lamp

(1) illumination

Proper lighting is a compromise to ensure good visibility and minimal glare and prevent the surgeon from eye strain. At 1 meter from the light source, the maximum central illuminance (Ec) of the center of the light plate must be between 40,000 and 160,000 lx. The size of the light sheet can vary depending on the type of surgery to limit peripheral glare. When the illuminance is greater than or equal to 10% of the maximum illuminance (EC), the glossy sheet is calculated. The diameter of this area is called D10.

The lighting must be uniform to reduce eye fatigue caused by glare. The diameter will be measured when the illuminance is 50% of Ec (called D50) and the ratio of D50/D10 will be given. The standard stipulates that the ratio shall not be lower than 0.5.

(2) Shadow management

In terms of shadow management, what is really important is that the surgical team has useful light when performing operations under the bald head, not the power of the bald head. The quality of light used in surgery depends on the amount of useful light in the cavity. This is a balance between the amount of light and shadow management capabilities. There are two types of shadows: cast shadows and contour shadows. Casting shadows affects visibility, and contour shadows can help us measure depth and volume. Effective lighting minimizes cast shadows while enhancing contours. Cast shadows are affected by the surface of the light source, how the light is directed to the operating field, where it is most needed, and the number of light sources. More beams improve the dilution of shadows and increase the visibility of surgeons.

(3) Amount of light

Because the operating cavity is not flat, the surgeon needs three-dimensional illumination. Combining multiple light sheets together-glowing and intensities at different heights simultaneously-creates a uniform volume of light. The amount of light is measured by the IEC standard equation: L1+L2. L1 is the distance between Ec and the 60% brightness measurement point, and L2 is the distance between Ec and the point where the brightness is measured 60% away from the operating lamp cap. The best surgical lights have the largest amount of light in the cavity, even if the light is more than one meter away from the surgical site. L2 measurement is especially important for deep cavity applications

(4) Thermal management

Light is always energy, so in order to prevent tissues from drying out, safe thermal management must be carried out. Heat can be measured in two places: in the light sheet and the lamp head. High temperatures can cause discomfort to the surgeon and dry out exposed patient tissue. Although LEDs do not produce harmful infrared rays, they still have some heat. The more light, the more radiant energy. The International Electrotechnical Commission limits the irradiance to no more than 1000W/m2. Overlapping light patches are always under the control of the surgeon. In order to prevent the bald head from overheating, it is also necessary to reduce the bald head overheating. High-quality surgical lights will minimize heat to improve comfort and patient prognosis.

(5) Fail-safe surgical lighting

There is no room for error in the operating room. The design of the fail-safe equipment ensures that there is no safety hazard even under a single failure condition. It guarantees lighting and mobility, and provides a central illuminance of not less than 40,000lx. Under single fault conditions, a single lamp without any protection against light interruption is not fail-safe. A lamp with two small lamps, with independent transformers, fuses, wires and slip rings, is fail safe. For example: the power cord is disconnected or the internal cable of the device is faulty, the fuse ring is broken or faulty.

Now you know the purpose of the operating lamp.