Professor Sidney Weinstein(1922-2010), an American neuropsychologist, together with psychologist Dr Josephine Semmes, developed the instrument originally referred to as the Semmes-Weinstein Pressure Aesthesiometer (SWPA), a calibrated series of nylon monofilaments inspired by the Von-Frey horse-hair instrument which permitted the quantification and classification of sensory loss in brain-injured patients. They used the monofilaments to map cortical areas of the brain in monkeys. The initial publication of normative thresholds in human subjects is found in the book Somatosensory Changes After Penetrating Brain Wounds in Man. When the US DuPont company first invented...