Design and Evaluation of a Computer-Controlled Pressure Algometer

A challenge is always presented when attempting to measure the pain an individual patient experiences. Unfortunately, present technologies rely nearly exclusively on subjective techniques. Using these current techniques, a physician may use a manually operated algometer and a series of questionnaires to gauge an individual patient’s pain scale. Unfortunately these devices and test methods have been suggested to introduce error due to variability and inconsistent testing methods. Some studies have shown large variability, while others have shown minimal variability, both between patients and within the same patient during multiple testing sessions. Recent studies have also shown a lack of correlation between pain threshold and pain tolerance in pain sensitivity tests. Hand-held algometer devices can be difficult to maintain consistent application rates over multiple test periods, possibly adding to widespread variability. Furthermore, there are limited test results that correlate pain ratings with biological measures in real time. The computer-controlled pressure algometer described is not hand-held or dependent on significant examiner input. This new device is capable of recording electrocardiograph (ECG), blood pressure (BP), pressure pain threshold (PPT), and pressure pain tolerance (PPTol) in real time. One major goal is the capability of correlating pain stimuli with algometer pressure, heart rate, and blood pressure. If a predictable correlation between vital signs and pain could be established, significant gains in the understanding of pain could result. Better understanding of pain will ultimately lead to improvements in treatment and diagnosis of pain conditions, helping patients and physicians alike.