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Surgical lighting technology

The OT lamp: A key in the operating room

An operating room lamp is a product most people can easily envision—its shape, purpose, and key attributes come to mind when thinking of a surgical light. Yet understanding what a surgical lamp truly is—or why operating lights have certain distinctive features—isn’t as straightforward.

Whether in an operating theater or an intensive care unit, surgical lighting is crucial for creating a comfortable environment for both physician and patient. RIMSA lamps ensure homogeneous, consistent illumination of the work area, delivering a highly intense beam of light that highlights every detail:

– Surgeons are supported at every step of their work.
– Patients benefit from a welcoming, reassuring atmosphere where they feel at ease and secure before undergoing surgery.

Surgical lighting: Shadow-free light

Surgical medical lamps, also known as “surgical”, derive their name from the Greek term meaning “without shadows.” They play a critical role in operating rooms by delivering strong, reliable, and uniform light to illuminate surgical areas. Over time, their development has mirrored the increasing complexity of surgical procedures. From eliminating shadows to illuminating deep cavities and integrating with digital technologies, today’s surgical lights must address modern needs while preserving their core function: shadow suppression.

Here below we explore what surgical lighting is.

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An historical overview of the surgical lamp

What does “scialytic” mean?

Surgical lights are also called “scyalitique” which, from Greek, means: without shadows.
The main feature of a surgical light is to illuminate a local area or a cavity of the patient with a strong and reliable light.
A surgical light must be well integrated into the operating room.
Light is a fundamental element of our life. When it comes to work, especially in the medical field, it is essential for the success of diagnoses, examinations and surgical operations.
The evolution of surgical lights has been slow, but today an important milestone has been reached thanks to cutting-edge technologies that guarantee high safety and high comfort for both doctors and patients.
RIMSA has developed the best lighting technology for operating rooms with the aim of ensuring that doctors and surgeons around the world can operate on their patients in optimal conditions.

The historical evolution of the device

The history of the surgical lamp is a journey of continuous evolution, where light has always played a pivotal role in advancing surgical practice. During the Renaissance, anatomical dissections were conducted in theaters like the Padua Anatomy Theater, built in 1595. Illumination relied on natural light from skylights or artificial light from candles, offering limited visibility. By the 19th century, with the introduction of anesthesia and antisepsis, surgery advanced, requiring stable and intense light to illuminate deeper cavities rather than just surfaces. This marked a turning point where shadow reduction became essential. In 1919, Professor Louis Vérain invented the first surgical lamp, utilizing an indirect reflection system that eliminated multiple shadows—solving one of surgery’s critical lighting challenges. This innovation was based on mirrors and later on lenses that diffused light uniformly across the operating field. During the 20th century, surgical lamps evolved further with advancements like halogen bulbs, which enhanced light intensity. However, the introduction of LED technology brought a revolution: greater energy efficiency, reduced heat output, and longer operational lifespans. Today, the surgical lamp is no longer a standalone light source but an integrated system within the modern operating room. Technologies such as double reflection (patented by Rimsa), indirect reflection, and systems like Always on Focus ensure constant illumination, free of glare, with exceptional color rendering for precise anatomical distinction. Compatibility with laminar flow systems ensures a sterile environment, while integration with cameras and digital systems provides recording and streaming capabilities for remote monitoring and surgical training. The modern surgical lamp embodies a delicate balance: it must continue to eliminate shadows—its name originating from the Greek words “skia” (shadow) and “lytikos” (to eliminate)—while meeting new demands for digitization, ergonomics, and sustainability. This transformation honors its historical legacy while embracing the future of advanced operating rooms.

The evolution of surgical lamp in RIMSA

RIMSA has played a pivotal role in the history of medical lamps.
In 2002, we introduced our first LED operating room lamp at a time when LED technology was still in its infancy and anti-glare solutions—now a standard—were barely being considered.
RIMSA surgical lamps quickly found their way into operating theaters worldwide, reshaping their appearance and the way doctors work on patients. With our patented anti-glare technology, operating room accidents declined significantly, and success rates for both invasive and minimally invasive procedures improved.
The reason is simple: glare is one of the biggest hazards in an OR. RIMSA’s specialized technology, integrated into every one of our medical lamps, eliminates this risk, delivering greater safety throughout each surgical phase.
RIMSA medical lamps were also the first to feature an indirect lighting system, expanding the typical LED beam, minimizing glare, and preventing shadows when objects or limbs obstruct the light. This indirect lighting concept, built into all major RIMSA surgical lamps, allows healthcare professionals to move freely without the risk of shadow-induced errors.

“Shadowless” is the term defining this type of professional lamp used in medical and surgical settings—commonly referred to as a surgical lamp outside the scientific community. Discover the technical specifications and regulatory requirements of RIMSA’s surgical lamps.

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The quality of light in surgical lamps: A complex balance of interdependent parameters

The quality of light in a surgical lamp hinges on three essential factors: illuminance, correlated color temperature (CCT), and color rendering index (CRI). While these parameters are crucial, evaluating them in isolation provides an incomplete picture. Their true significance lies in their interdependence, where one cannot be maximized without affecting the others.

What to consider for quality lighting

Light intensity: Lighting without compromise

The luminous intensity is the amount of light emitted and measured in lux. The IEC 60601-2-41 standard states that a scialytic lamp must provide a minimum of 40,000 lux to ensure adequate visibility during surgery, with a maximum limit of 160,000 lux to avoid visual damage to the surgeon. However, extremely high values, if not accompanied by other balanced parameters, can be unnecessary or even counterproductive. For example, too bright light with poor colour rendering can produce glare and visual fatigue, affecting the visibility of anatomical details.

Color temperature (CCT): The light shade

CCT refers to the light’s color tone, measured in Kelvin (K). Warmer lights (3,000–4,000K) are easier on the eyes but may lack the depth illumination needed for surgery. Conversely, cooler lights (5,000–5,500K) provide better surface illumination but distort natural colors, creating visual discomfort over extended periods. There is no universally perfect CCT—achieving the right balance depends on the clinical setting and specific surgical needs.

Color Rendering Index (CRI): Accurate Color Perception

The CRI measures how accurately a light source reproduces colors compared to natural light. The standard requires a CRI of ≥ 85, which is sufficient for surgical accuracy. Pushing for CRI values above 90 yields minimal perceptible benefits to the human eye while imposing significant trade-offs: increased energy consumption, reduced LED lifespan, and compromised performance. CRI values are also averages, meaning they cannot remain consistent over the lamp’s operational lifespan due to LED degradation.

Interdependence: The core of light quality

These parameters—illuminance, CCT, and CRI—are deeply interconnected:
1. Higher illuminance can diminish CRI if the LEDs are not properly optimized.
2. CCT influences CRI: Cooler light may improve brightness but at the cost of color fidelity, while warmer light enhances CRI but limits depth visibility.
3. LED lifespan suffers when any single parameter is pushed to its extreme, highlighting the need for balance.
This interdependence explains why IEC 60601-2-41 avoids imposing rigid values and instead focuses on a balanced approach. A surgical lamp should not excel at one parameter alone—it must achieve an optimal harmony of brightness, color accuracy, and temperature to ensure comfort, precision, and energy efficiency.

The need for a comprehensive index

A synthetic index that evaluates all three parameters—illuminance, CCT, and CRI—would offer a holistic assessment of light quality. Unfortunately, no such tool currently exists. Isolated measurements remain the norm, often leading to unrealistic demands, such as CRI 99 or excessive illuminance. These extreme values are inefficient, unnecessary, and environmentally unsustainable, offering no tangible benefits to surgical outcomes.
In summary, the quality of light in surgical lamps cannot be reduced to individual values. It requires a thoughtful balance of interdependent parameters to deliver stable, effective, and reliable illumination. Pushing for extreme numbers may sound impressive, but only balanced light ensures optimal performance in the operating room.

3

How to control light

In surgical lighting, reflection technology plays a vital role in ensuring precision, safety, and efficiency within the operating room. Over time, lighting technologies have evolved, offering solutions that cater to different surgical requirements and environments. Today, the choice of reflection—direct or indirect—defines the performance of surgical lamps and their ability to support complex procedures.

The evolution of reflection technologies: Direct reflection VS Indirect reflection

In the era of halogen lamps, indirect reflection was the only feasible option. This method uses reflective parabolic surfaces to diffuse light, reducing glare and enhancing the illuminated area. The advent of LED technology introduced the possibility of both direct and indirect reflection, each with its unique benefits and challenges.

Indirect Reflection

Safety and Optical Efficiency

Indirect reflection uses surfaces specifically designed to diffuse light through reflective parabolas, maximizing the luminous emission area. This approach ensures major benefits:
1. It reduces glare—essential for the surgeon’s comfort and safety—and it enhances the luminous surface area.
2. It improves efficiency by enabling uniform light distribution and reducing shadows.
However, this technology requires highly specialized production processes and is therefore often used in high-volume sectors.

Advantages of Indirect Reflection

Indirect reflection means safety and comfort. Its ability to minimize glare protects the surgeon’s eyes and enhances focus during complex procedures. It also increases the luminous surface, ensuring even light distribution without the need for complex electronic adjustments. This approach is typical in high-precision applications like automotive headlights, where glare elimination is crucial.

Disadvantages of Indirect Reflection

Producing lamps with indirect reflection is more complex than using direct lighting technology. It requires accurate design and greater precision in manufacturing processes, making it less common outside high-tech sectors. Nonetheless, the benefits in terms of safety and visual comfort far outweigh the production challenges.

Direct Reflection

Limits and Challenges of Direct Reflection

Direct reflection technology sends light straight from the LEDs to the surgical field. While easier to manufacture, it presents several significant drawbacks:
1. Requires a higher number of high-power LEDs, leading to increased heat and energy consumption.
2. Smaller light-emitting surface, which reduces compatibility with laminar airflow and increases shadow formation.
3. Needs complex electronic systems to suppress shadows, raising the risk of malfunctions and reducing visual comfort.

Disadvantages of Indirect Reflection

Although direct reflection is simpler to produce, it comes with important compromises. It relies on more or stronger LEDs, which generate excessive heat and consume more energy—worsening airflow compatibility and increasing glare. The reduced light-emitting surface results in lower shadow suppression, which must then be compensated for electronically. This approach is not only inefficient but contradicts the very essence of a surgical light: eliminating shadows.

4

Risk related to the use of a surgical lamp

Surgical lights play a central role in the operating room (OR), providing the critical illumination surgeons need to perform procedures with accuracy. Yet, their use is not without significant risks. Research and professional literature highlight several issues associated with surgical lighting systems (also known as surgical luminaires or scialitiche) that can impact patient safety, as well as the overall wellbeing of the surgical team. On one hand, glare represents a major source of visual fatigue, distracting the surgeon and impairing intraoperative vision. On the other, handle contamination and disruptions to the laminar airflow can increase the risk of infections. Additionally, older lighting technologies may produce excessive heat, raising the risk of burns and altering the delicate airflow patterns designed to keep the surgical field sterile.

How to correctly use a surgical lamp

The risks of glare and excessive luminance

One of the most critical problems linked to surgical lights is glare, often caused by excessive luminance. While typical working environments require only about 700-1,500 lux, surgical lights can produce up to 160,000 lux. This intense brightness forces the surgeon’s eyes to constantly adapt, leading to eye strain, irritation, blurred vision, and difficulty maintaining focus. High-contrast transitions—such as shifting from the brightly lit surgical site to the darker surroundings—trigger continuous readjustments of the eyes. Over time, these conditions contribute to neck, shoulder, and back pain, ultimately affecting both the surgeon’s long-term health and the procedure’s outcome. Increased fatigue and discomfort heighten the risk of errors, diminishing the quality of patient care.

Contamination risks and disruption of laminar airflow

Surgical lights can also serve as unintended vehicles of contamination. The supposedly sterile handle used to adjust the light’s position is often manipulated by the surgeon, making it challenging to maintain perfect asepsis throughout a long procedure. Studies suggest that up to 50% of these handles may be contaminated by the end of certain operations. Furthermore, the physical presence of the light, combined with the heat it generates, can disrupt the laminar airflow—an engineered downward flow of filtered air intended to minimize bacterial presence at the surgical site. When this airflow is compromised, the risk of infection and postoperative complications significantly increases.

Thermal risks and patient burns

Although rare, there are documented cases where surgical lights contribute to patient burns or even operating room fires. Excessive light intensity or incorrect positioning of the light source too close to the patient’s skin can lead to heat-related injuries. Certain substances on the patient’s skin may react oddly to intense illumination, causing chemical burns. While modern LED lighting systems have greatly reduced the risk of heat emission and related injuries, vigilance remains essential.

The solutions? Technology and best practices

Modern solutions: Technology and best practices
Fortunately, advanced technology offers tangible solutions to mitigate these risks. LED-based surgical lights significantly minimize infrared emissions, thus reducing heat buildup and lowering the chance of burns. Similarly, indirect lighting systems help diffuse the beams, eliminating pinpoint hotspots and decreasing glare. Some lighting designs incorporate a “compensation area” around the surgical field, creating a smoother transition between bright and dim zones, easing the surgeon’s visual workload.
Materials and ergonomics also matter. Lightweight structures, ergonomic handles, and flexible arms make it easier to reposition lights without breaching sterility. Proper installation and careful attention to ceiling height, room layout, and the positioning of other ceiling-mounted equipment help preserve the laminar airflow. Reducing the need to frequently adjust the light source leads to fewer handle contacts, decreasing contamination risks.

Conclusions

A surgical light is far more than a simple lamp; it is a sophisticated medical device that directly affects safety, comfort, and surgical outcomes. By embracing the latest technologies—LED lighting, indirect illumination, advanced materials, and well-planned room configurations—healthcare facilities can effectively reduce glare, contamination, and thermal hazards. The key is to prioritize light quality over sheer intensity and adhere to best practices. With the right combination of technology and proper handling, the operating room becomes a safer, more efficient environment for both patients and surgical staff.

5

Exclusive RIMSA lights features

The advantages of RIMSA surgical lamps

Indirect Reflection

LED technology has significantly reduced the light emission surface area. A smaller emission surface negatively impacts the surgical effect—namely, shadow prevention. Aware of this issue, RIMSA introduced an Indirect Light technology that increases the light emission surface, delivering an optimal surgical effect.

Double Reflection​

In 2017, RIMSA patented its double-reflection technology, maximizing the light emission surface area. Implemented in the UNICA series and certain veterinary lamps, this innovation achieves exceptional shadow-free illumination while offering a fully glare-free lighting environment.

Compensation Area

Certain surgical specialties—like thoracic, abdominal, and cesarean procedures—demand a wider, high-intensity lighting field. An additional optical system expands the illuminated field to 30 cm (approx. 12 inches) while maintaining 6000 Lux at the outer edge, without reducing central light intensity (Ec).

Luminous Emission Surface

RIMSA shadowless lamps excel in illumination quality thanks to a luminous emission surface designed for even and intense light diffusion. This results in superior brightness and ideal visibility across various surgical applications.

Constant Focus

RIMSA lamps feature an advanced “always-in-focus” system, ensuring precise and uniform illumination, even if the reflector is moved. This technology maintains optimal visibility in the operative field at all times, with no need for frequent adjustments.

RIMSA’s Solution: Indirect Reflection with Double Reflection

At RIMSA, we believe in the superiority of indirect reflection and enhance it further with our double-reflection technology. This approach boosts the light emission surface and further reduces glare, guaranteeing maximum safety and comfort for surgeons. Double reflection represents the future of surgical lighting, and RIMSA stands at the forefront of this technological revolution.

6

OR Integrations

Modern operating rooms have evolved into sophisticated, interconnected ecosystems designed to enhance surgical precision, improve efficiency, and support better patient outcomes. RIMSA recognizes the importance of modular systems that accommodate various needs and seamlessly integrate with other OR devices. We provide the full array of equipment required to design a comprehensive and efficient operating suite.

7

Positioning

RIMSA shadowless lamps offer extraordinary flexibility in positioning and configuration, adapting to the diverse demands of each operating room. Depending on the type of surgery, they can be set up individually or used in combination to ensure optimal lighting at all times. This adaptability maximizes the surgeon’s visual comfort and enhances the overall patient experience, contributing to a safer, more efficient surgical environment.

RIMSA lamp configuration

Unica 520 + 520
Unica 860 + 520
U29 + U29
Pentaled 63N + 63N
Pentaled 63N + 30N

Unica 860 + 520
U29 + U29
Pentaled 63N + 63N

Unica 860 + 520 + 520
Unica 520 + 520 + 520
U29 + U29 + U29
Pentaled 63N + 63N + 30N

Pentaled 30N + 30N
Pentaled 30E + 30E
Pentaled 28 + 28

Unica 520
U29
Pentaled 63N

Unica 520 + 520
U29 + U29
Pentaled 63N + 30N

Alfa Flex

Unica 520
U29
Pentaled 63N

Pentaled 30N
Pentaled 30E

L88 Led
Prima Fix

Prima Fix

Pentaled 30N
Pentaled 30E
Pentaled 28
Pentaled 12

Pentaled 12
Pentaled 28
Saturno Led

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Medical Disciplines

Drawing on more than 80 years of experience and technological expertise, RIMSA produces medical lamps for every department and setting. Whether you need lighting for an operating room, an outpatient clinic, or a routine medical exam, the RIMSA catalog offers the ideal medical lamp to suit your needs.
Explore all our solutions!

We’ve compiled a series of concise video segments showcasing the key features of RIMSA’s shadowless lamps, offering a clear and immediate overview of our exceptional surgical lighting. Each piece highlights a fundamental aspect of RIMSA’s technology, developed to best support operating room professionals with reliable, innovative, and high-performing solutions.

Light sources in the operating room

Lighting technologies

Glare effect

Compensation area

Maneuverability

Laminar flow

Camera

Double reflection

Learn more!

“Emergency lighting” is the RIMSA manual that contains all information about the technologies of our lamps.

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