Design of a Compact Laparoscopic Probe for Optical Stimulation of the Cavernous Nerves


TOZBURUN S., Fried N. M.

Conference on Photonic Therapeutics and Diagnostics V, San-Jose, Costa Rica, 24 - 26 January 2009, vol.7161 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 7161
  • Doi Number: 10.1117/12.807484
  • City: San-Jose
  • Country: Costa Rica
  • Keywords: optical stimulation, nerve, prostate, cavernous nerves, laparoscopic probe, ERECTILE FUNCTION, RAT PROSTATE, IDENTIFICATION
  • Dokuz Eylül University Affiliated: No

Abstract

The cavernous nerves are responsible for erectile function and course along the prostate surface, varying in size and location among patients, making preservation of sexual function challenging after prostate cancer surgery. Electrical stimulation has proven inconsistent and unreliable in identifying these nerves and evaluating nerve function. Optical stimulation of the rat cavernous nerves has recently been reported as a alternative to electrical stimulation, with potential advantages including noncontact stimulation and improved spatial selectivity. This study describes the design of a compact laparoscopic probe for future clinical use in optical nerve stimulation. The 10-Fr (3.4-mm-OD) prototype laparoscopic probe includes an aspheric lens for collimation of the laser beam with a 0.8-mm-diameter spot, coupled with a 200-mu m-core optical fiber. A 45 degrees gold-coated rod mirror in the probe tip provides side-firing delivery of the laser radiation. The probe handle houses a miniature linear motorized stage for lateral scanning of the probe tip over a 25-mm line along the prostate surface. A 5.5-W Thulium fiber laser with tunable wavelength range of 1850-1880 nm was tested with the probe. The probe fits through a standard 5-mm-ID laparoscopic port and is capable of delivering pulse energies up to 8 mJ (1.6 J/cm(2)) at a 2.5-ms pulse duration, well above the threshold (similar to 0.35 J/cm(2)) for optical stimulation of the cavernous nerves.