no noise from working units.
Enhanced background lighting: Power LED RUBINA provides more background illumination than normal Xenon D‐Light P sources, resulting in improved surgical visualization and accuracy.
Improved Safety. Since the Power LED Rubina contains only LED technology and no laser light or Xenon bulbs, these units do not require the use of specific wavelength polarized protecting goggles during procedures, thus resulting in increased safety, freedom, and better ergonomics for the surgeons.
These modern units allow for image overlay of NIR/ICG imaging over the standard white light image, enhancing the surgeons tissue perception.
Light Cables
A fiber optic cable transmits the light from the source to the telescope. It consists of a bundle of thousands of optical glass fibers ranging in size from 30 to several hundred microns, surrounded by a protective jacket, and equipped with metal fittings at each end. Cables with additional armoring last longer than ones without this protection. The cable is inserted into the light source at one end and attached to the light post of the telescope at the other end. Light cables are available in various styles and diameters, depending on the diameter of the telescope. Correct matching prevents overheating or under illumination. Generally, a smaller scope requires a smaller light cable. The most common cable used with 5‐mm telescopes for small animal MIS is 3.5 mm in diameter and 300 cm long (Table 3.2) [1–5]. The extended length 300 cm light cables provide better ergonomics since in most laparoscopic and thoracoscopic procedures a minimum of 1.5 m distance exists between the operating table and the surgical field. A free range of motion increases the surgeon's ability and ergonomics resulting in faster and safer procedures and also avoids excess drag to the imaging equipment setup.
Table 3.2 Matching diameter of telescope and light cable for optimal illumination and to avoid overheating.
| Telescope diameter (mm) | Recommended cable diameter (mm) |
|---|---|
| 6.5–12 | 4.8–5.0 |
| 3.0–6.5 | 3.0–3.5 |
| 0.8–2.9 | 2.0–2.5 |
Careful handling of a light cable will prolong its life span, avoiding discoloration of the ends and breakage of individual fibers. Light cable integrity is assessed by looking through one end of the cable toward a room light or window. However, over time discoloration reduces light transmission and can change the color of the light that is emitted. Broken fibers will appear as small black or gray areas. When more than 30% of the fibers are broken, replacement of the cable is recommended. Excessive bending, twisting, or crushing of light cables should be avoided to minimize fiber breakage.
Contemporary light cables are autoclavable, but manufacturers' recommendations for time and cycle should be carefully followed using an appropriate sterilizer. Light cables should always be stored alone in adequate containers in a loosely coiled position, to minimize stress on the glass fibers.
When considering fluorescence technologies, a specific light cable is mandatory due to intrinsic wavelengths' transmission ability. Depending on the configuration of the video system, one should consider “fluorescence fluid” or “fluorescence fiberoptic” light cables. Since the most common fluorescence applications in veterinary surgery use ICG, the more frequently chosen type of cable corresponds to the fiber optic version.
Endoscopic Video Cameras
The video camera system consists of the camera head, CCU, and monitor. Heads include adapters with different focal lengths that determine the displayed image size. However, image size and magnification can be adjusted more conveniently with an integrated optical zoom knob located on the camera head. Optical zoom produces a true magnified image without compromising the resolution, unlike digital zoom, which merely increases pixel size [1–5, 8, 13].
An important consideration may be the flexibility of the chosen camera for different procedures and different endoscopes. It may be prudent to consider both a variable focal distance head as well as a CCU that is compatible with all the types of scopes that might be used in practice (fiberscopes, videoendoscopes, and rigid telescopes). Multidisciplinary and versatile systems may support a broad endoscopy service for a reasonable investment. Larger practices may, however, consider having separate systems for different services [1–5].
Medical cameras contain a computer “chip,” which transforms the optical image into an electronic signal transmitted to the CCU. Recent improvements in miniaturization of complementary metal‐oxide‐semiconductor (CMOS) “chips” have led to standardization of CMOS cameras as high‐end quality devices whose performance and image quality are equivalent or superior to earlier CCD (charge‐coupled device) cameras [1–5].
Although endoscopic camera quality has previously been defined by single‐chip or three‐chip technology, it is currently more relevant to embrace HD image technology. An HD image can be produced with either a single CMOS chip or three‐chip camera, which provides a wide screen display (Figure 3.8a). The HD aspect ratio of 16 : 9 more closely approximates the human visual field than the historical 4 : 3 standard and allows the surgeon to observe instruments entering the surgical field sooner than with a traditional monitor [1–5].
However, HD cameras differ in resolution and light sensitivity, performance characteristics that affect detail recognition, color, features, and price. Some newer cameras, for example, have integrated image capturing capabilities or image processing options that enhance contrast or brighten dark areas (see Enhanced Contact Endoscopy section below). Full HD cameras deliver superior picture resolution (1920 × 1080 pixels) and progressive scanning, as opposed to interlaced scanning. The progressive scanning method simultaneously displays all 1080 lines for every frame, thus producing the smoothest, clearest image, especially when the video content is motion intensive.
New generation full HD camera heads have titanium bodies, making them light, robust, and autoclavable, in contrast to older models only sterilizable by gas or soaking [1–5, 8, 9]. Newer camera heads provide intraoperative access to customizable functions with the push of a button on the head, such as white balance, image capture, video recording, image enhancement, zoom, and many others.
For standard veterinary abdominal and thoracic MIS procedures, a CMOS single‐chip FULL HD camera head and CCU are considered the standard of care, bringing to practice the best and most affordable medical technology. Nevertheless, for specific or more advanced applications, dedicated technologies are also available.
Figure 3.8 (A) FULL HD CMOS single chip lightweight camera, 1920 × 1080 pixels. Zoom can be activated by programmed touch button in camera head. (B). 4K camera with NIR/ICG, IMAGE 1 STM 4U RUBINA.
Source: © KARL STORZ SE & Co. KG, Germany.
It is critical to remember that for endoscopic images to be displayed in HD, each component of the imaging chain must be HD compatible, from
