An apparatus and method embodying the invention including utilizing a device with a limited number of interrogation devices to accomplish a large number of measurements on a target tissue. An instrument embodying the invention includes a plurality of detection devices that are arranged in a predetermined pattern on a tissue contacting face of the instrument. The face of the instrument is located adjacent the target tissue, and a plurality of tissue characteristic measurement are simultaneously conducted. The detection devices are moved to a new position, preferably without moving the tissue contacting face, and a second plurality of tissue characteristic measurements are simultaneously conducted. By conducting a series of measurement cycles in this manner, the ultimate resolution of the device is increased, while still obtaining a given resolution, which reduces potential cross-talk errors. Further, a plurality of tissue characteristics are simultaneously obtained from locations spaced across the target tissue during each measurement cycle.