0
Research Papers

Design and Evaluation of a Computer-Controlled Pressure Algometer

[+] Author and Article Information
Michael M. Zimkowski

Department of Mechanical Engineering,  University of Colorado Boulder, 1111 Engineering Drive, 427 UCB, Boulder, Colorado 80309

Emily M. Lindley

Assistant Professor Department of Orthopaedics,  University of Colorado Denver, 13001 E 17th Place, Aurora, Colorado 80045

Vikas V. Patel

Associate Professor Department of Orthopaedics,  University of Colorado Denver, 13001 E 17th Place, Aurora, Colorado 80045

Mark E. Rentschler

Assistant Professor Department of Mechanical Engineering,  University of Colorado Boulder, 1111 Engineering Drive, 427 UCB, Boulder, Colorado 80309-0427mark.rentschler@colorado.edu

J. Med. Devices 5(3), 031002 (Jul 27, 2011) (6 pages) doi:10.1115/1.4004416 History: Received August 19, 2010; Revised May 27, 2011; Published July 27, 2011; Online July 27, 2011

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.

FIGURES IN THIS ARTICLE
<>
Copyright © 2011 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

The computer-controlled pressure algometer (CCPA) design, with a load cell contained in a custom housing, and an application tip driven by an actuator

Grahic Jump Location
Figure 2

The cross section of the computer-controlled pressure algometer (CCPA). The device consists of an air cylinder with piston, load cell, and an application tip connected via two plates.

Grahic Jump Location
Figure 3

The identical applications tips used on the Wagner FDIX and the CCPA

Grahic Jump Location
Figure 4

The basic computer-controlled pressure algometer (CCPA) design flow diagram, outlining two data acquisition systems and their respective input and output components

Grahic Jump Location
Figure 5

The basic computer-controlled pressure algometer (CCPA) control box design diagram, outlining the air flow path from the inlet to the actuator, and the redundant emergency stops controlling the air solenoid operation

Grahic Jump Location
Figure 6

The subject’s testing position, with the computer-controlled pressure algometer (CCPA) placed on the tibialis anterior muscle

Grahic Jump Location
Figure 7

Algometer pressure graph of the computer-controlled pressure algometer (CCPA), showing algometer pressure, and a threshold event at 226 kPa and tolerance event at 350 kPa

Grahic Jump Location
Figure 8

Application rate calculation of the computer-controlled pressure algometer (CCPA), showing a 10 kPa/s application rate around the threshold event

Grahic Jump Location
Figure 9

Blood pressure graph of the computer-controlled pressure algometer (CCPA), showing systolic and diastolic blood pressure as a function of voltage and time

Grahic Jump Location
Figure 10

Electrocardiograph of the computer-controlled pressure algometer (CCPA), showing clearly visible R-R wave intervals, enabling heart rate calculation on the order of seconds

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In