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16 August 2000 Thermal effects in laser-assisted embryo hatching
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Proceedings Volume 4065, High-Power Laser Ablation III; (2000)
Event: High-Power Laser Ablation, 2000, Santa Fe, NM, United States
Diode lasers [(lambda) equals 1480 nm] are used with in-vitro fertilization [IVF] as a promoter of embryo hatching. A focused laser beam is applied in vitro to form a channel in the zona pellucida (shell) of the pre-embryo. After transfer into the uterus, the embryo hatches: it extrudes itself through the channel and implants into the uterine wall. Laser-assisted hatching can result in improving implantation and pregnancy success rates. We present examples of zone pellucida ablation using animal models. In using the laser it is vital not to damage pre-embryo cells, e.g. by overheating. In order to define safe regimes we have derived some thermal side-effects of zona pellucida removal. The temperature profile in the beam and vicinity is predicted as function of laser pulse duration and power. In a crossed-beam experiment a HeNe laser probe detects the temperature-induced change in refractive index. We find that the diode laser beam produces superheated water approaching 200 C on the beam axis. Thermal histories during and following the laser pulse are given for regions in the neighborhood of the beam. We conclude that an optimum regime exists with pulse duration <EQ 5 ms and laser power approximately 100 mW.
© (2000) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Diarmaid H. Douglas-Hamilton and Jerome D. Conia "Thermal effects in laser-assisted embryo hatching", Proc. SPIE 4065, High-Power Laser Ablation III, (16 August 2000);

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