Our Technology


About Prosthetic & Orthotic Associates

Our Prosthetic Technology – NPS (Vacuum) Socket System

The prosthetic technology is our patented NPS system utilizes a vacuum chamber to remove air from the space between a sheath or sock, the socket of the prosthesis and the liner. The vacuum created by the removal of the air attaches the liner evenly to the socket wall without squeezing. The liner acts like a “second skin,” so the residual limb is not directly exposed to the vacuum. Unlike other prosthetic suspension systems which focus the weight and force of the prosthesis on one point at the bottom of the socket, vacuum systems spread the pressures evenly over the entire socket. The limb does not shift within the socket because captured air is forced out through an opening at the bottom of the socket, which maintains the vacuum with a valve that closes the opening.

Negative Pressure Suspension (NPS) Socket Technology – For ALL Levels of Amputation.

The Negative Pressure Suspension (NPS) socket system developed by Stan Patterson, CP, has been used with considerable success for persons with transtibial (BK), transfemoral (AK), hip disarticulation, and hemipelvectomy/transpelvectomy amputations. POA has successfully fit more than 30 hip disarticulation patients in the past year and has fit up to three hemipelvectomy patients in a single week.

Benefits of NPS System:

The prosthetic technology in our patented Vacuum Chamber System (less weight and moving parts, healthier skin, more intimate fit, less volume change throughout the day) incorporated into AK, BK, hip disarticulate and hemipelvectomy sockets.

Proven results with AK systems including lower trim lines and unique alignment techniques which allow for a more natural gait. Successfully fit over 30 Vacuum Hip Disarticulate sockets in the past year including many soldiers from Walter Reed Army Medical Center. R & D Center dedicated to improving technology and finding solutions for hard-to-fit patients. Intense Gait and Activity Training specialized to Your Needs!

Negative Pressure Suspension provides remarkable benefits for the Transfemoral Amputee: Negative Pressure Suspension, Transfemoral Amputee:

  • Reduces pistoning and limb movement.
  • Maintains limb volume throughout the day.
  • Increases blood flow and oxygenation of tissue.
  • Decreases skin abrasions, blisters, and friction.
  • Permits evaporation of perspiration.
  • Allows for lower trim lines.
  • More adaptable to weight gain/loss.
  • Increases comfort, control, and proprioception.
  • Light-weight; no moving parts.

NPS sockets provide a superior interface with skin and tissue. Studies have shown that conventional methods of interfacing residual limbs with prosthetic devices (figure A) decrease blood flow and oxygenation of tissue, cause blisters, traps perspiration, and causes sores and abrasions. The NPS Socket promotes healthier skin and increased comfort.