CENTRAL NERVOUS SYSTEM EFFECTS OF LASER RADIATION
Abstract
Experiments were conducted to determine the effects of focused and unfocused laser radiation upon the scalp, cranium, and brain parenchyma of mice and rats. With an unfocused beam, no gross on microscopic lesions of the brain parenchyma were produced when the beam was directed onto the intact and unshaved scalp and cranium. With a beam focused on the unshaved scalp the skin was burned, but the cranium was intact. Subdural, subarachnoid, and focal intracerebral hemorrhage was produced in the brain parenchyma of mice but not of rats under these conditions. When the beam was aimed onto the head and focused so that the focal point would be inside the cranium and within the brain parenchyma along a track that corresponded with the focal depth, most of the mice died within minutes after such experiments when the output was about 20-40 joules. Similar lesions were produced in rats, but the rats were less affected generally and the results were not immediately fatal. The experiments suggest that the human hair, scalp, and skull would be sufficiently thick and dense to protect the brain from focused or unfocused laser radiation up to the 40-joule output and probably much higher energies, but the brains of small animals such as rats and mice can be severely damaged by a focused beam that is partially transmitted through the scalp and skull.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1963
- Accession Number
- AD0612442
Entities
People
- J. R. Hayes
- Kenneth M. Earle
- Martin A. Ross
- Stirling Carpenter
- Uros Roessmann
Organizations
- Armed Forces Institute of Pathology