Penile Rigidity: The Rigiscan
"Bradley and Timm (1985) first described the RigiScan Plus monitor (Timm Medical Technologies, Eden Prairie, Minnesota), an instrument designed to measure continuously both circumference and radial rigidity, and that can be used in real-time or ambulatory mode. The device consists of a recording unit, that can be strapped around the waist or thigh, and has two loops, one that can be placed around the base of the penis and the other just behind the corona. Each loop contains a cable that is tightened at discrete time intervals. Circumference is measured at 15-second intervals. The Rigiscan takes its first rigidity measure when a 20% increase in circumference is detected. This is repeated every 30 seconds (see Figure 1). To measure rigidity, the loops tighten a second time after circumference is measured, with a force of 2.8 Newton."From Janssen, E., Prause, N., & Geer, J. (2007). The sexual response. In J. T. Cacioppo, L. G. Tassinary, & G. G. Berntson (Eds.), Handbook of Psychophysiology, 3rd ed. New York: Cambridge University Press.