Vincent Chan
The information and models provided in this upload are the result of a nine-month Mechanical Engineering capstone at the University of Washington.
The goal of this project was to create a quantitative, accurate means of measuring capillary refill time (CRT) in children. The provided solution uses a clothespin-like apparatus and a smartphone camera to apply blanching pressure to a subject's fingertip and detect changes in skin color.The procedure closely follows that of the nail blanch test, substituting the hand and eye of an clinician with a mechanical presser and an onboard video-processing algorithm.
The device consists of three seperate 3D-printable entities and a companion Android application. Some additional components are required to complete the final device: the smartphone itself (an HTC Desire 620G Dual Sim), a small 12 in-lb torsion spring, and a 21.4 mm x 21.4 mm x 11.75 mm block of clear plastic. The printable components are as follows:
An early version of the Android app used to interface with the device is available. The app prompts the user to apply and release pressure, takes a video of the finger during and after the process, and performs colorimetric analysis on the video data to determine CRT. Please contact creator personally for further information.