The Use of Non-Ionizing Radiation to Temporarily Change the Index of Refraction of Biological Tissues
Life Sciences : Medical Devices
Available for licensing
- Ashley Welch, Ph.D. , Biomedical Engineering
- Rebecca Vincelette, Ph.D. , Biomedical Engineering
- H. Grady Rylander III, M.D. , Biomedical Engineering
- Thomas Milner, Ph.D. , Biomedical Engineering
When a biological sample is exposed to a laser radiation source, some of the radiation is absorbed, creating a temperature profile in the exposed area. Laser-radiation wavelengths in the near-infrared region are strongly absorbed in water, and subsequently, in many biological tissues. This temperature gradient leads to a change in the index of refraction and consequently the laser beam’s profile in the tissue. As long as the exposure conditions are safely below damage threshold conditions, the alterations in the media induced by the absorption of laser radiation are completely reversible.
When the biological sample is the eye, the near-infrared laser radiation disrupts the path length the light travels through the eye, impacting visual acuity. If the refractive conditions are known, the degree of visual alteration from a selected near-infrared wavelength could be known when the characteristics of the thermal lens are well understood. Exposure conditions, below the maximum permissible exposure level, to the retina from near-infrared laser radiation can induce a significant thermal lens, safely, and reversibly disrupting visual acuity.
- The induced change in the index of refraction is temporary and reversible as long as the exposure to the near-infrared radiation source is below damage threshold.
- The use of a near-infrared laser as the source for creating the index of refraction change allows for specific localized control of the reversible process.
Has market applications as a visual disruptor.