Abstract: An apparatus for measuring skin tactile thresholds and, thus, skin irritation comprises a set of unitarily formed monofilaments whose tips are textured and curved. The unitary tip of the monofilament accordingly does not break or fall off, and due to its texture and curvature is accordingly capable of contacting a skin surface with substantially no slippage for eliciting tactile pressure stimulations that are more consistently of the pressure type than the conventional esthesiometer, which elicits both pressure and pain stimulations randomly. The present apparatus consistently stimulates a skin site with pressure stimuli of various intensities and the perceptual experience of each pressure stimulation can accordingly be accurately recorded in each of two modalities: touch and pain.

Abstract: A method of measuring the itch sensitivity of a skin surface of a subject patient comprises applying a unitarily formed elongated stimulating monofilament having a curved, textured stimulating tip at a free end thereof to contact the skin surface of the subject patient. The stimulating monofilament is dragged both distally and proximally across the skin surface, and a degree of itch rating of the subject patient is recorded. An apparatus for delivering such pressure-induced sensations to a subject skin surface includes a handle having a distal portion for applying a stimulus and a proximal portion grippable by a user. The apparatus further includes a plurality of heads coupled to the distal portion of the handle, and a plurality of elongated stimulating monofilaments of varying diameters each attached to a respective one of the plurality of heads for contacting the subject skin surface.

Abstract: A method of measuring the itch sensitivity of a skin surface of a subject patient comprises applying a unitarily formed elongated stimulating monofilament having a curved, textured stimulating tip at a free end thereof to contact the skin surface of the subject patient. The stimulating monofilament is dragged both distally and proximally across the skin surface, and a degree of itch rating of the subject patient is recorded. An apparatus for delivering such pressure-induced sensations to a subject skin surface includes a handle having a distal portion for applying a stimulus and a proximal portion grippable by a user. The apparatus further includes a plurality of heads coupled to the distal portion of the handle, and a plurality of elongated stimulating monofilaments of varying diameters each attached to a respective one of the plurality of heads for contacting the subject skin surface.

Abstract: Apparatus for the determination of corneal thresholds, for example the corneal center, through the use of air flow to specific corneal sites, comprises a "stimulate" air flow path leading from an air compressor through a stimulate nozzle to the cornea for stimulation, and a "non-stimulate" air flow path leading from the air compressor to a calibrate nozzle, so that the force in the stimulate nozzle may be set before stimulation. A further "exhaust" air flow path is provided quickly to exhaust air from the stimulate nozzle to provide a sharp turn-off of the force of the air flow applied to the optic cornea, thereby obtaining a substantially rectangular stimulation characteristic. The nozzle is wide and flat with a dimple or recess formed substantially at or near the center thereof where air exits therefrom, so that the force and extent of air needed to stimulate the cornea is limited.