Development and evaluation of a light-emitting diode endoscopic light source (original) (raw)
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Experimental Evaluation and Analysis of LED Illumination Source for Endoscopy Imaging
International Journal of Integrated Engineering, 2022
In surgery, minimally invasive techniques (MIT) are generally safer than open surgery and typically faster recovery. This biological photographic surgery has increased interest in LED-based treatments. LEDs have now become essential in medical and dental technology. But the demands placed on these devices are extreme. Minimal size, large and application-specific colour rendering index, efficient temperature control, usability, and excellent disinfection opportunities are all important. An endoscopy is a process where the doctor uses specialized instruments to look and operate on the body's internal parts like organs and vessels. It allows experts to view disease within the body without making a large body cut. Endoscopy surgery requires an average of 45 minutes. It involves the use of an external illumination source. Considering intense illuminance and colour rendering index (Ra) greater than 95, Xenon, Halogen, and Metal halide lamps are recently used as an illumination source in minimally invasive techniques. These sources emit a broad visible frequency spectrum,
Multi-channel LED light source for fluorescent agent aided minimally invasive surgery
2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2014
Cancer is one of the most common and deadly diseases around the world. Amongst all the different treatments of cancer such as surgery, chemotherapy and radiation therapy, surgical resection is the most effective. Successful surgeries greatly rely on the detection of the accurate tumor size and location, which can be enhanced by contrast agents. Commercial endoscope light sources, however, offer only white light illumination. In this paper, we present the development of a LED endoscope light source that provides 2 light channels plus white light to help surgeons to detect a clear tumor margin during minimally invasive surgeries. By exciting indocyanine green (ICG) and 5-Aminolaevulinic acid (ALA)-induced protoporphyrin IX (PPIX), the light source is intended to give the user a visible image of the tumor margin. This light source is also portable, easy to use and costs less than $300 to build.
Feasibility of using an led-probe in third-space endoscopy: a clinical study
BMC Gastroenterology, 2020
Background Third-space endoscopy is a novel, safe, and effective method for treating different gastrointestinal conditions. However, several failed endoscopic procedures are attributed to incomplete myotomy. Lighting devices are used to prevent organic injuries. We aimed to investigate the feasibility of using a hand-made LED-probe (LP) in third-space procedures. Methods This prospective study was conducted in a tertiary-care center in Mexico between December 2016 and January 2019. We included peroral endoscopic myotomy (POEM) and gastric peroral endoscopic myotomy(G-POEM) procedures. Pseudoachalasia, peptic ulcer, normal gastric emptying scintigraphy (GES) and prepyloric tumors were excluded. LP was used to guide or confirm procedures. Clinical and procedural characteristics were recorded and analyzed. Results Seventy third-space procedures were included (42POEM,28G-POEM), with an average patient age of 46.7 ± 14.3 and 43.7 ± 10.1 years, respectively. For the POEM and G-POEM groups...
Characterization of multi-emitter tuneable led source for endoscopic applications
2019
In this paper we describe our own construction of a tuneable light source based on a set of light emitting diodes covering the visible spectrum using a homogenizing rod instead commonly used low energy-efficient integrating spheres. The expected prime application of the source is a medical endoscopic system, however it is possible to use it also for other purposes requiring both multispectral operation and a tuneable white light source. We describe the construction of the source and include precise characterization of the output white light – distribution of CCT, Duv, Δu′ v ′ and colour rendering indexes (Ra, R9, Rf , Rg) of light in several planes located at various distances. The obtained results prove that our source is characterized by very good colour rendition according to the Ra and Rf method for various correlated colour temperatures (2700–6500) K. As an example of application images of the Macbeth colour chart registered with an RGB camera included in the laboratory measure...
Surgical Endoscopy and Other Interventional Techniques, 2009
Introduction Current arc-lamp illumination systems have a number of technical and ergonomic limitations. White light-emitting diodes (LEDs) are energy-efficient solidstate lighting devices which are small, durable and inexpensive. Their use as an alternative to arc-lamp light sources in minimal access surgery has not been explored. This study aims to develop an LED-based endo-illuminator and to determine its lighting characteristics for use in minimal access surgery. Methods We developed an LED endo-illuminator using a white LED mounted at the tip of a steel rod. Offline image analysis was carried out to compare the illuminated field using the LED endo-illuminator or an arc-lamp based endoscope in terms of uniformity, shadow sharpness and overall image intensity. Direct radiometric power measurements in light intensity and stability were obtained. Visual perception of fine details at the peripheral endoscopic field was assessed by 13 subjects using the different illumination systems. Results Illumination from the LED endo-illuminator was more uniform compared to illumination from an arc-lamp source, especially at the closer distance of 4 cm (0.0006 versus 0.0028 arbitrary units -lower value indicates more uniform illumination). The shadows were also sharper (edge widths of 16 versus 44 pixels for the first edge and 15 versus 61 pixels for the second edge). The overall mean image intensity was higher (127 versus 100 arbitrary units) when using the autoshutter mode despite the lower direct radiometric power, about one tenth of the arc-lamp endoscopic system. The illumination was also more stable with less flickering (0.02% versus 5% of total power in non-DC components). Higher median scores on visual perception was also obtained (237 versus 157, p \ 0.001). Conclusion The LED endo-illuminator provides more uniform illumination with sharper shadows, less flickering and better illumination for visual perception than the arclamp-based system currently used.
Light-Emitting Diode-Assisted Narrow Band Imaging Video Endoscopy System in Head and Neck Cancer
Clinical Endoscopy, 2015
The use of narrow band imaging (NBI) is currently considered of great benefit in detecting superficial mucosal lesions over the pharyngeal mucosa. 3 A literature review revealed that the effectiveness of NBI in the early detection of head and neck squamous cell carcinoma (SCC) of the larynx, 4 mouth floor, 5 nasopharynx, 6 oropharynx, and hypopharynx 7,8 has been documented over time. The NBI system (Olympus Medical Systems, Tokyo, Japan) is a noninvasive optical device that uses reflected light to visualize the superficial structure and enhance vasculature within the mucosal layer. NBI provides a unique image that emphasizes the morphological and structural character of lesions as well as their surface capillary patterns. The first clinical study of the NBI system for the diagnosis of gastrointestinal tumors was reported by Sano et al. 9 in 2001. Unique images are created by the sequential lighting of the tissue through an endoscope, and the sequence of light is produced by a rotation disk with red, green, and blue optical filters placed in front of a high-power white light source, typically a xenon lamp. The physical phenomena are based on the fact that the penetration depth of light is dependent on its wavelength (i.e., Background/Aims: To validate the effectiveness of a newly developed light-emitting diode (LED)-narrow band imaging (NBI) system for detecting early malignant tumors in the oral cavity. Methods: Six men (mean age, 51.5 years) with early oral mucosa lesions were screened using both the conventional white light and LED-NBI systems. Results: Small elevated or ulcerative lesions were found under the white light view, and typical scattered brown spots were identified after shifting to the LED-NBI view for all six patients. Histopathological examination confirmed squamous cell carcinoma. The clinical stage was early malignant lesions (T1), and the patients underwent wide excision for primary cancer. This is the pilot study documenting the utility of a new LED-NBI system as an adjunctive technique to detect early oral cancer using the diagnostic criterion of the presence of typical scattered brown spots in six high-risk patients. Conclusions: Although large-scale screening programs should be established to further verify the accuracy of this technology, its lower power consumption, lower heat emission, and higher luminous efficiency appear promising for future clinical applications.
Endoscopic Observation of Tissue by Narrowband Illumination
Optical Review, 2003
We propose a new illumination method for a medical endoscope: narrow band imaging (NBI), in which the spectral bandwidth of the filtered light is narrowed. To confirm how the spectral specifications of the filtered light influence a reproduced image, an experiment was conducted observing the endoscopic images of the back mucosa of a human tongue. In addition, the effect of NBI on endoscopic images was investigated through preliminary clinical tests in colonoscopy and upper gastrointestinal endoscopy. It has been shown that NBI can enhance the capillary pattern and the crypt pattern on the mucosa. These patterns are useful features for diagnosing an early cancer.
Journal of Biomedical Optics, 2014
The near-infrared (NIR) fluorescence signal in the 700 to 900 nm from molecular probes used in fluorescence image-guided surgery (FIGS) is usually weak compared to the NIR component from white light-emitting diode surgical light, which is typically switched off during FIGS to enhance the molecular fluorescence contrast of the image. We propose a simple solution to this critical issue in FIGS by removing NIR light from surgical light with a low cost commercial 3M cool mirror film 330.
Choosing Surgical Lighting in the LED Era
Surgical Innovation, 2009
Background. The aim of this study is to evaluate the illumination characteristics of LED lights objectively to ease the selection of surgical lighting. Methods. The illuminance distributions of 5 main and 4 auxiliary lights were measured in 8 clinically relevant scenarios. For each light and scenario, the maximum illuminance E c (klux) and the size of the light field d 10 (mm) were computed. Results. The results showed: that large variations for both E c (25-160 klux) and d 10 (109-300 mm) existed; that using auxiliary lights reduced both E c and d 10 by up to 80% and 30%; that with segmented lights, uneven light distributions occurred; and that with colored LED lights shadow edges on the surgical field became colored. Conclusions. Objective illuminance measurements show a wide variation between lights and a superiority of main over auxiliary lights. Uneven light distributions and colored shadows indicate that LED lights still need to converge to an optimal design.
Asian journal of endoscopic surgery, 2014
Organic electroluminescence displays (OELD) use organic materials that self-emit light with the passage of an electric current. OELD provide high contrast, excellent color reproducibility at low brightness, excellent video images, and less restricted viewing angles. OELD are thus promising for medical use. This study compared the utility of an OELD with conventional liquid crystal displays (LCD) for imaging in orthopedic endoscopic surgery. One OELD and two conventional LCD that were indistinguishable in external appearance were used in this study. Images from 18 patients were displayed simultaneously on three monitors and evaluated by six orthopedic surgeons with extensive surgical experience. Images were shown for 2 min, repeated twice, and viewed from the front and side (diagonally). Surgeon rated both clinical utility (12 parameters) and image quality (11 parameters) for each image on a 5-point scale: 1, very good; 2, good; 3, average; 4, poor; and 5, very poor. For clinical uti...