Surgical Endoscopy

, Volume 23, Issue 3, pp 518–526

Solid-state semiconductors are better alternatives to arc-lamps for efficient and uniform illumination in minimal access surgery

  • Alex C. H. Lee
  • Daniel S. Elson
  • Mark A. Neil
  • Sunil Kumar
  • Bingo W. Ling
  • Fernando Bello
  • George B. Hanna
Article

DOI: 10.1007/s00464-008-9854-7

Cite this article as:
Lee, A.C.H., Elson, D.S., Neil, M.A. et al. Surg Endosc (2009) 23: 518. doi:10.1007/s00464-008-9854-7

Abstract

Introduction

Current arc-lamp illumination systems have a number of technical and ergonomic limitations. White light-emitting diodes (LEDs) are energy-efficient solid-state 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 arc-lamp-based system currently used.

Keywords

Illumination Light-emitting diode Minimal access surgery Solid-state semiconductor 

Copyright information

© Springer Science+Business Media, LLC 2008

Authors and Affiliations

  • Alex C. H. Lee
    • 1
  • Daniel S. Elson
    • 1
  • Mark A. Neil
    • 2
  • Sunil Kumar
    • 2
  • Bingo W. Ling
    • 3
  • Fernando Bello
    • 1
  • George B. Hanna
    • 1
  1. 1.Department of Biosurgery and Surgical TechnologyImperial College LondonLondonUK
  2. 2.Blackett Laboratory, Department of PhysicsImperial College LondonLondonUK
  3. 3.Centre for Digital Signal Processing ResearchKing’s College LondonLondonUK