Figure 3-18-19 Mistake-Proofing the Design of Health Care Processes - Figure 3.18. A commercially available, automatic wheelchair locking device Return to Document Figure 3.19. Wheelchair does not move, locking device engaged Return to Document Current as of May 2007 Internet Citation: Figure 3-18-19: Mistake-Proofing the Design of Health Care Processes -. May 2007. Agency for Healthcare Research and Quality, Rockville, MD. http://www.ahrq.gov/professionals/quality-patient-safety/patient-safety-resources/resources/mistakeproof/mistakefig3-18-19.html