Continuous-wave (CW) and time-resolved (pTOFS) diffuse reflectance spectroscopy measurements are rapid, non-invasive optical methods widely adopted to gain diagnostic information of tissue. The most flexible approach to these methods is fiber-optic contact probes used with spectroscopy systems. A challenge when using these methods is that the external pressure on the tissue caused by the probes can significantly affect the tissue optical properties as well as the light coupling out of and into the probes, and thus influence the recorded spectrum.