Lightfield adaptable surgical luminaire concept.

Visual performance and visual comfort are a combined effect of the illumination characteristics and the illuminated objects. Current surgical lighting systems have a fixed shape illumination pattern, whereas the wound and surroundings have a variable shape and characteristics. A lighting system that is able to adapt its shape and light distribution to the characteristics of the wound might improve visual performance. This paper describes the development of a new concept for lighting using bendable strips with LEDs. The basic idea of placing LEDs on a bendable surface is very simple and elegant. To achieve a functional system, the effects of the different design choices, such as shape of the strips, number of LEDs, number of strips, and LED power were investigated. The influence of these choices is evaluated by simulation using a computational model to identify the optimal parameters for the design. The final design is evaluated using the computational model and a physical prototype consisting of one luminaire segment. The system is able to produce light fields that can have fairly complex shapes at a good range of different sizes. Recommendations about aspects like spot size and strip number are given. The physical test model indicates that the calculated system functions close to how it would in a real-life situation. Given the results, it expected that a system, which is able to modify the light field in real time and that requires minimal control effort, could improve lighting in the operating room.

Directions for surgical capacity developments in Nepal: a population-based assessment.

OBJECTIVES: Lack of access to safe surgery is seen as a major issue that needs to be addressed. The aim of this study was to understand which combinations of factors relate to high occurrences of unmet needs and disability in Nepal, and consequently, how to focus future work to maximise impact in this country. METHODS: A large population-based survey was conducted in Nepal in 2014 to evaluate the unmet surgical needs that result in disability. Recorded factors included diseased anatomical areas, disease specifics, disease locations, injury types, reasons for having an unmet need and the types of disability. RESULTS: Included in the study were 2695 individuals. The anatomical areas facing the highest disabling unmet surgical need were Head (3.9% of population), Groin/Genitalia (2.2% of population) and Extremities (3.6% of population). Four focus areas could be defined. Increase affordability, availability and acceptability of surgical care to non-traumatic disabling conditions of (i) the eye, and (ii) extremities, and (iii) to traumatic disabling conditions of extremities and finally (iv) increase acceptability of having surgical care for non-traumatic conditions in the groin and genital area. For the latter, fear/no trust was the main reason for receiving no surgical care despite the resulting shame. CONCLUSIONS: This study defined four focus areas that showed the largest unmet needs that resulted in a perceived disability. For those areas, affordability, availability and acceptability of surgical need to be addressed through technical developments, capacity building and raising awareness.

OBJECTIFS: L'absence d'accès à une chirurgie sûre est considérée comme un problème majeur à résoudre. Le but de cette étude était de comprendre quelles combinaisons de facteurs étaient liées aux besoins non satisfaits et aux incapacités au Népal, et par conséquent, comment cibler les travaux futurs pour maximiser l'impact dans ce pays. MÉTHODES: Une vaste enquête de population a été menée au Népal en 2014 pour évaluer les besoins chirurgicaux non satisfaits qui entraînent une incapacité. Les facteurs enregistrés comprenaient les zones anatomiques, les spécificités, les localisations de la maladie, les types de blessures, les raisons pour lesquelles les besoins n'étaient pas satisfaits et les types d'incapacité. RÉSULTATS: 2695 personnes ont été incluses dans l'étude. Les zones anatomiques impliquées dans des besoins chirurgicaux les plus invalidants étaient les suivantes: tête (3,9% de la population), aine/organes génitaux (2,2% de la population) et extrémités (3,6% de la population). Quatre domaines cibles d'intervention pourraient être définis. Premièrement, augmenter l'accessibilité financière, la disponibilité et l'acceptabilité des soins chirurgicaux aux affections invalidantes non traumatiques de 1) l'œil, 2) des extrémités et 3) aux affections traumatisantes des extrémités, et enfin 4) augmenter l'acceptabilité des soins chirurgicaux pour les affections non traumatiques dans l'aine et les parties génitales. Pour ces derniers, la crainte/l'absence de confiance était la principale raison de ne pas recevoir de soins chirurgicaux malgré la honte qui en résultait. CONCLUSIONS: Cette étude a défini quatre domaines cibles d'intervention qui ont montré les besoins non satisfaits les plus importants ayant entraîné une incapacité perçue. Pour ces domaines, il convient de prendre en compte le caractère abordable, la disponibilité et l'acceptabilité des interventions chirurgicales par le biais de développements techniques, d'un renforcement des capacités et la sensibilisation.

Single-sided and small-scaled grasping of delicate tissues: effectiveness of indirect heat-induced attachment and detachment.

INTRODUCTION: Indirect heat-induced attachment and detachment (iHIAD) is a promising concept for gripping delicate tissues in microsurgery. However, the optimal settings of iHIAD are unknown. This study evaluates the effects of the instrument heating properties and initial contact force on the adhesion force, detachment success and thermal damage. MATERIAL AND METHODS: An instrument prototype was developed to test attachment and detachment for different combinations of generated energy (3.5-20.0 mJ) and pulse length (0.25-2.50 ms). The tissues tested on were kidney and eye from the pig. Thermal tissue damage was estimated with a histological analysis. RESULTS: The adhesion force F(a) depended strongly on the amount of generated energy (F(a) = 0.03-2.5 mN) and contact force (F(a) = 0.25-1.0 mN). Pulse length played a minor role. Detachment success (0-100%) was determined by generated energy (3-16 mJ). Histological analysis showed minimal damage. CONCLUSION: Adhesion forces increased with increasing contact forces. iHIAD proved sensitive to heating characteristics. Detachment success increased with generated energy. Thermal damage was minimal. iHIAD creates a potential to build better performing tissue manipulators.

Evaluation of a new surgical light source for difficult visibility procedures.

A new lighting device for open surgery of difficult access wounds was designed: the Extender add-on. The performance of the Extender is evaluated and compared with the conventional solutions used in the operating room (OR) on illumination quality. A cylindrical setup was built to measure the distribution of light in a simulated pelvic wound. The light was provided by a head-mounted light, an OR light, and a pair of Extender prototypes. The results showed that the Extender prototypes provided 12.2 lumens inside the wound, whereas the head-mounted light gave 5.7 lumens. The Extenders provided smoothly angular distributed light from 0° to 180°, whereas the head-mounted light and OR light only provided light from 115° to 180°. The Extender prototypes had a promising performance in terms of light distribution. It is expected that a more accurately produced Extender will increase performance in terms of illumination quantity and illumination distribution smoothness even further.

Indicating shortcomings in surgical lighting systems.

Ergonomic problems of surgical lighting systems have been indicated by surgeons; however, the underlying causes are not clear. The aim of this study is to assess the problems in detail. Luminaire use during 46 hours of surgery was observed and quantified. Furthermore, a questionnaire on perceived illumination of and usability problems with surgical luminaires was issued among OR-staff in 13 hospitals. The results showed that every 7.5 minutes a luminaire action (LA) takes place, intended to reposition the luminaire. Of these LAs, 74% were performed by surgeons and residents. For 64% of these LAs the surgical tasks of the OR-staff were interrupted. The amount of LAs to obtain a well-lit wound, the illumination level, shadows, and the illumination of deep wounds were most frequently indicated lighting aspects needing improvement. Different kinematic aspects of the pendant system of the lights that influence usability were also mentioned: High forces for repositioning, ease of focusing and aiming, ease of moving, collisions of the luminaire, entangling of pendant arms, and maneuverability. Based on these results conclusions regarding the improvement of surgical lighting systems are formulated. Focus for improvements should be on minimizing the need for repositioning the luminaire, and on minimizing the effort for repositioning.

Choosing surgical lighting in the LED era.

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.