title: Design, testing, and clinical studies of a handheld polarized light camera.
abstract: Polarized light imaging has been used to detect the borders of skin cancer and facilitate assessment of cancer boundaries. A design for an inexpensive handheld polarized camera is presented and clinical images acquired with this prototype are shown. The camera is built with two universal serial bus (USB) color video cameras, a polarizing beamsplitter cube, and a 4x objective lens. Illumination is provided by three white LEDs and a sheet polarizer. Horizontal and vertical linearly polarized reflected images are processed at 7 frames/s and a resulting polarized image is displayed on screen. We compare the performances of cheap USB camera and a 16-bit electronically cooled camera. Dark noise and image repeatability are compared. In both cases, the 16-bit camera outperforms the USB cameras. Despite these limitations, the results obtained with this USB prototype are very satisfactory. Examples of polarized images of lesions taken prior to surgery are presented.
authors.affiliation: Oregon Medical Laser Center, Providence St. Vincent Medical Center, Portland, Oregon, USA.
authors.forename: Jessica C
authors.initials: JC
authors.lastname: Ramella-Roman
authors.forename: Ken
authors.initials: K
authors.lastname: Lee
authors.forename: Scott A
authors.initials: SA
authors.lastname: Prahl
authors.forename: Steven L
authors.initials: SL
authors.lastname: Jacques
mesh_terms: D003195:Computer Communication Networks / Q000295:instrumentation; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D008545:Melanoma / Q000473:pathology*; D008859:Microscopy, Polarization / Q000295:instrumentation* / Q000379:methods; D018715:Microscopy, Video / Q000295:instrumentation* / Q000379:methods; D008904:Miniaturization; D010781:Photography / Q000295:instrumentation / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*; D012878:Skin Neoplasms / Q000473:pathology*; D014741:Video Recording / Q000295:instrumentation* / Q000379:methods