Often overlooked and taken for granted, lighting is an essential element that gains attention only when it falls short. When it comes to the operating room, surgical lights play a crucial role as they enable surgeons to effectively examine and treat patients. Many people, however, would erroneously believe that brighter light is preferable. However, in the operating room, quality rather than quantity is most important. In this blog post, we will explore the essential factors that you may wish to consider when buying high-quality LED OT lights.
Technical Terminologies about LED OT Lights
Before we begin discussing the elements that go into creating high-quality LED OT lights, it’s crucial to comprehend a few technical terms.
Lux is the unit of measurement for light intensity at a certain point, which is measured with a lux meter. One lux means one lumen per square.
Color temperature refers to the evaluation of a light source’s color in relation to an optimal light source. It is measured in Kelvin and ranges from 1,000 to 10,000. Certain LED lights offer the flexibility to adjust the color temperature, enabling surgical teams to modify the light properties and enhance tissue differentiation.
Color Rendition Index (CRI)
The color rendering index (CRI) is a metric that evaluates how accurately a light source reproduces eight specific pastel colors. The idea behind CRI is that if a light source renders these colors well, it should generally render all colors accurately. CRI serves as a straightforward and useful specification for predicting the visual performance of a lighting product. It is a measure of light quality.
Typically, daylight has a CRI value of 100. The closer the CRI value of an operating theatre light is to 100, the more accurately an operating room light can render genuine colors to the human eye. Lighting products with “good” color rendition typically have a CRI value of over 80. To calculate the CRI of a light source, the differences between reference colors R1-R8 are averaged under the light source tested with a reference light source, such as incandescent light or sunlight.
While the color rendering index (CRI) does not include the measurement of R9, the discussion of LED light quality often emphasizes the importance of R9. R9 represents how accurately a light source can render a saturated deep red color. This is particularly significant in surgical settings as it allows surgeons to better recognize details in wound areas and differentiate between tissue colors and arterial or venous blood.
By the way, the color choice for the walls and surfaces in operating rooms serves a specific purpose. They are typically light blue-green because it is the complementary color of red, which is the color of blood. By using this blue-green color, operating rooms avoid a phenomenon called successive contrast, which allows individuals involved in the procedure to give their eyes a rest when they shift their gaze away from the operating table.
Surgeons will readily notice the difference when R9 values are above 70, as red tones appear more vibrant and vivid. This enhancement assists in faster and more accurate tissue identification and diagnosis. A lighting source could have a high CRI level yet a low R9 level. For example, when halogen lights produce a higher color temperature, they also emit more heat. Manufacturers often employ dichroic reflectors to reduce infrared (IR) light, which produces heat. However, in the process of filtering out the undesirable IR light in a halogen light, some of the beneficial visible red light is also filtered out. This directly causes poor R9 color rendition, despite the light’s high CRI value. In contrast, LED lighting produces light at higher levels than halogen lighting and is independent of heat and color.
Central Illuminance (Ec)
Central Illuminance refers to the illuminance (lx) at a distance of 1 meter from the light-emitting surface in the center of the light field, which is measured in lumens per square meter. To ensure optimal performance, it is crucial for the light source to be capable of achieving both a high level of illuminance and excellent color rendition simultaneously.
The alternative option in case the main power supply is disrupted.
Key Factors to Consider When Buying LED OT Lights
Illumination is a measure of light intensity that is perceived by the human eye when it hits or passes through a surface. In the context of surgical sites, tissues and organs tend to absorb a significant amount of light and have poor reflective qualities. Therefore, surgical lights need to provide sufficient illumination to enable accurate perception. However, it is important to note that more illumination does not necessarily equate to better outcomes. Excessive illumination can lead to issues such as glare, loss of contrast, and eye fatigue. IEC recommends that the light in the operating room falls within the range of 40,000 to 160,000 lux.
In the case of surgical lights, the central illumination is typically measured at a distance of 1 meter below the light head.
Effective Distribution of Light
In surgical procedures, it is crucial to have an efficient distribution of light, especially when examining deep-set body openings. Even if some of the LEDs are not in use, the illumination ought to be continuous, and shadows ought to be kept to a minimum. To achieve this, a design is required where the arrangement of LEDs ensures that the entire area is consistently illuminated at all times. This design is particularly advantageous in situations where a few LEDs may fail or become obstructed by the surgeon’s hands or head. Despite such occurrences, the performance of the dome light remains unaffected, ensuring that the surgeon’s view remains unobstructed and unhindered.
A distinguishing characteristic of high-quality LED surgical lights is their white color appearance. This is crucial for maintaining the optimal color temperature during surgeries, enabling surgeons to accurately differentiate between various body tissues, flesh colors, and fluids. Lights with various color tones can be deceptive and change how the patient’s tissues seem, endangering surgeons’ work and the safety of their patients.
The International Electrotechnical Commission (IEC) mandates that the color temperature of surgical lights falls within the range of 3,000 to 6,700 Kelvin. As a reference, daylight typically ranges between 5,500 and 6,500 Kelvin. Colors above 5,000 Kelvin are considered “cool” colors, giving off a blueish-white appearance. In longer surgeries, a 5,000 Kelvin light might be preferred to lessen eye fatigue.
Conversely, colors with lower values on the Kelvin scale are referred to as “warm” colors. Halogen bulbs, for instance, inherently produce yellow light with typical color temperatures around 3,200 Kelvin. Manufacturers have attempted to mitigate the yellow light by using expensive coatings and filters, which raises the color temperature to a more acceptable level of around 4,400 Kelvin. While this process makes halogen lighting appear whiter, it often compromises color rendition.
Color Rendering Index
Color rendition is a crucial factor in determining the quality of LED light used in surgical procedures. It plays a significant role because conventional lighting can distort the color and overall appearance of objects. According to the IEC standard, it is required to have a CRI of over 85 to ensure accurate color perception for diagnostic purposes and proper recognition of tissues by practitioners. Once the CRI surpasses 90, the human eye becomes less sensitive to discern any further differences in color rendition.
Even the brightest light will be inadequate if it leaves undesired shadows in the operating room. Shadows can be categorized into contour shadows, which are useful for differentiating fine tissue striations and vasculature, and contrast shadows, which obstruct the surgeon’s view and pose a problem. Contrast shadows are typically caused by obstructions cast by hands or instruments.
To address this issue, it is important to select a light that reduces contrast shadows while still providing enough contour shadows for optimal perception by surgeons. This is why surgical lights often have dual or triple light heads and multiple bulbs on each head, providing for lighting from various angles.
Flexibility in Movement
Flexibility in movement is also crucial for LED operating theater (OT) lighting systems. The ability to adjust the arms and rotation during surgeries is essential for the comfort and easy movement of practitioners while keeping the focus on the surgical procedure.
Lighting systems with 360-degree rotation around the central axis and at both ends of the revolving axis offer this flexibility without the need for suspension or dragging of arms. This range of movement allows for easy positioning and adjustment of the light’s direction, depth, focus, and color according to the specific requirements of the procedure. It enables the lighting system to minimize the impact of shadows and provides greater flexibility and precision during surgeries.
Before purchasing lighting equipment, it is crucial to consider the ease of sterilization, particularly for the handles. The cleanability of the lighting systems should be thoroughly examined. To prevent the retention and accumulation of dust and debris, the luminaires should be designed with smooth edge transitions. The lighting fixtures should have a high level of ingress protection and a streamlined, watershed design to facilitate adherence to rigorous sanitation protocols.
To withstand stringent infection control procedures, including the use of caustic chemicals, gas sterilization, or UV sterilization, all exposed surfaces of the light fixture should be protected against corrosion. While offering sterile controls for movement and control of the light functions, the design should also consider a simple, effective, and safe cleaning schedule without the need for harsh chemicals.
Fail-safe equipment is designed to maintain essential functions of illumination and maneuverability even in the event of a single fault condition where no safety hazard exists. Fail-safe lights are capable of providing a minimum illuminance of 40,000 lx for a duration of five seconds during any interruption.
The use of smart electronics with independent circuits can contribute to fail-safe operation by enhancing reliability and safety measures. Having double OR light configurations, as well as incorporating battery backups or utilizing mobile versions of lighting systems, can provide additional protection against potential issues or power interruptions.
If summarizing a high-quality LED light, it should be a balanced design that is equipped with high illumination, effective distribution of light, optimal color temperature, color rendering index, reduced shadow, flexibility in movement, infection control and fail safe. These criteria being met will make it easier to find products of high quality.
Choose LED OT Lights at MOKO
When choosing LED OT lights, it’s vital to find lights that balance the factors above. Mokologht is designed with this in mind. Backed by reliable test data, we offer world-class LED medical lights, including LED OT lights to clinics, medical facilities, dentist offices, operating rooms, research facilities, and more. Reach out to us today to find out more.