Safety issues with lasers systems have had to be addressed at the Laser Institute of America’s International Laser Safety Conference, due to the unimaginable advances the technology has experienced in the past ten years. Held 23-26 March in Albuquerque, New Mexico, ILSC 2015 also hosted talks focused on niche applications such as atypical research stations and space exploration.
LIA President Robert Thomas of the Air Force Research Laboratory noted: ‘Lasers of immense peak powers, hand-held laser devices with power that cannot have been imagined a decade ago, and ever-expanding applications of the laser.’
A lack of laser safety officers in healthcare facilities was indicated as a pressing area of concern, and dealing with the laser powers now available needs addressing as well.
In the medical realm, longstanding discussions of the dangers of surgical smoke and precautions to avoid patient airway fires during surgery were fuelled by many case studies of accidents — including one that resulted in $30 million in damages. In that 2012 case in Washington State, a 53-year-old woman with a history of vocal cord polyps suffered extensive burns and eventually died when the endotracheal tube being used ignited during surgery with a CO2 laser.
Numerous factors played into the accident, according to attorney Matthew Wojcik, including insufficient training of the surgeon, anaesthesiologist and ‘laser nurse.’ Furthermore, the surgeon was unfamiliar with the tube used, and the hospital’s Laser Safety Officer had left two years prior and not been replaced by someone similarly credentialed.
Amplifying the need for more certified medical laser safety officers, Richard Gama of UHS discussed the laser rental company’s informal survey that found about 40 per cent of 266 health-care facilities responding did not have a CMLSO or laser safety programme.
Robert Scroggins of Buffalo Filter shared the latest information about the deleterious particles that can be present in and transferred by surgical smoke. Surgical smoke contains over 40 hazardous chemicals, he said, including carcinogens. Interactions of chemicals in the plume can be more hazardous than individual components like benzene. Biological components like HPV, HIV, viral DNA and Hepatitis B virus can sit in the lungs; there are even documented cases of cancer in surgeons who performed laser surgeries and were subjected to the plume.
For industrial laser uses, more powerful and brighter lasers will require continuous development of hazard prevention and industrial work stations. David Havrilla of Trumpf noted that diode-pumped disk lasers could enter the terawatt regime, but are currently being combined to achieve outputs of 20kW to 30kW. He also noted that Trumpf and IFSW Stuttgart achieved more than 1.3kW average power at picosecond pulse duration.
Tim Webber of IPG Photonics detailed advances in fibre laser powers on the order of 30kW to 100kW, for instance in welding applications for shipbuilding. These significant power densities will require ‘a little bit more science and a little bit more study’ to properly address brightnesses and barrier requirements, Webber noted.
A laser will be found in a less traditional research environment when a team sets up a powerful 400mJ device at a summit camp on the Greenland ice cap. With temperatures ranging from a summer high around minus 11 degrees Celsius to winter lows around minus 50, researchers have had to model potential beam behaviour as it interacts with super-cold particles like snow and fog, said Michael O’Neill of the University of Colorado, Boulder. The goal is to protect workers in the building housing the autonomous system, which will run 24 hours a day, seven days a week in a location at 3.2km altitude and about 500 miles from the coast.
Looking beyond the horizon and into space, Patrick Shriver of Metatech examined the risks of accidental lasers strikes on satellites and their sensitive optical sensors. He suggested an international registry to document most lasers that can propagate beams into or through space, including space-based lasers. From there, safe-operation standards could be created.
Powerful protection - With lasers becoming more powerful and with solid-state systems like fibre lasers now more commonly used in manufacturing, Jessica Rowbury examines the safety precautions necessary when using laser equipment