He was the first to develop scintillating vapor-deposited Na(Tl) thin films for photon counting imaging detectors grown with a columnar structure for high spatial resolution.
[4] Shepherd designs and develops dual-energy X-ray absorptiometry systems, mammography and 3D optical biomarkers used to evaluate the risk of osteoporosis, breast cancer, and obesity.
[5] He serves as the principal investigator for the National Institute of Diabetes and Digestive and Kidney Diseases funded Shape Up!
Since 2020, Shepherd and his research team at the University of Hawaii Honolulu Cancer Center are working on Astro-3DO, the project which will use 3D optical cameras to measure the body shape and mass composition of astronauts in space.
[6] Since 2021, he was appointed as Deputy Director and Chief Scientific Officer at the University of Hawaii Honolulu Cancer Center.