Reinventing the algometer: Synopsis of the literature and presentation of a reliable, inexpensive model

Abstract

This article summarizes the historical development ofthe algometerirtscirntiflcinvestigations and notes hallmarks in the evolution of the device. The algometer has served as a safe nociceptive stimulus for more than a century. Although the earliest renditions were inexpensive, they were often unreliable and difficult to operate. More modern versions have brought reliability, but at increased expense and complexity. Newer versions have failed to make the device easy enough to use to be practical. The "reinvented" algometer is reliable, less expensive than commercial devices, and easy to build and use. These improvements should allow greater application of the algometer in empirical research and assessment of pain.

Effects of Systematic Sleep Fragmentation on Tolerance and Threshold in a Pressure Pain Task: Associations with Sustained Attention

“…Pain measurement devices come in several varieties; the device used here, an algometer, specifically assesses pressure-pain at a distal extremity (the fingers). I utilized an administration technique for the pressure algometer that was developed by other researchers to permit measurement of both pain threshold and pain tolerance in an escape paradigm (Rainwater & McNeil, 1991; details below).…”

“…Research personnel escorted participants to the lab, which neighbored the sleep laboratory (in the same research wing) and where distractions, although likely minimal, would have been consistent across testing. The primary researcher was trained by staff of the lab that originally developed the device (Rainwater & McNeil, 1991) to provide as much behavioral consistency across administration conditions as possible.…”

“…The weight was immediately removed from the apparatus once a participant indicated that the pain was no longer tolerable. Applied pressure also affects circulation to the distal extremity, so each session was limited to three minutes of weight exposure to prevent tissue damage (Rainwater & McNeil, 1991). The algometer task was administered eight total times; twice (AM/PM) after the last night of sleep at home, twice (AM/PM) after an acclimatization night in-lab, and twice (AM/PM) after each experimental night (SHAM or FRAG) in-lab.…”

“…The goal of this research was to evaluate whether sleep fragmentation reduced pain threshold and tolerance to determine the importance of sleep continuity in the perception of and nocifensive response to pressure stimuli. This research targeted the effects of sleep fragmentation by systematically interrupting the sleep of otherwise healthy adults while extending their overall sleep opportunity to minimize sleep restriction, and used a behavioral measure of pain threshold and tolerance to a mechanical pressure stimulus for relevance to clinical populations (Rainwater & McNeil, 1991). Sustained attention performance was also measured before and after sleep fragmentation using the PVT to evaluate the extent to which attention participated in the sleep-pain relationship.…”

“…Because pain threshold and tolerance are independently defined constructs (IASP, 1986;Rainwater & McNeil, 1991) that may be differentially sensitive to sleep disruption, they were measured separately in this work. There is convincing evidence reporting changes in pain after attentional manipulation (see Introduction [p.14]).…”