Optical microsystem design and fabrication for medical image magnification

Medical imaging is an important part of diagnosis. The procedure should provide valuable information for diagnosis and, at the same time, should be minimally invasive for the patient. Therefore, when performing endoscopic imaging, a system with reduced dimensions is crucial. The performance of imaging systems, used in several diagnosis endoscopic procedures, would highly benefit from the integration of an imaging magnification optical microsystem (IMOM) able to perform in vivo and real-time tissue microscopy. This paper proposes a miniaturized IMOM: its total length is 12.164 mm and has a lateral lens assembly of 3.894 mm. A microfabricated PDMS lens was included in the system, obtained by a hanging droplet approach, a very low-cost and effective method. A paraxial magnification of 4-14 times was achieved with a good performance in every optical analysis evaluated. A modulation transfer function around 38 % at 50 lp/mm was obtained and maximum distortion about 1.8 %.