Knee Replacement – Pre and Post-Operative Physical Therapy Machine

Challenge:

Halley Orthopedics an innovator in pre and post operative therapy machines for knee replacement patients had a critical project to implement a number of improvements in their next generation therapy machine in development.

Key objectives of the project included:

• Portability:
  • The new generation X10 machine needed to weigh significantly less to make it portable. The previous actuation system weighed over 80 lbs.
  • Portability would significantly open the market for the X10.
• Special sequencing and control features:
  • Incorporation of new safety features in the actuator to prevent over-travel.
  • Real-time communications with the patient for therapy settings and recording of leg travel.

Kyntronics Solution:

Kyntronics worked closely with X10 Therapy Engineers during the design phase to develop and configure a rotary actuator that would meet these requirements for their next generation machine.

The new system incorporated Kyntronics Electro-Mechanical SMART Actuator, a modified model R2400 which provided 2,400 in-lbs of torque capability. Using Kyntronics standard actuator building blocks, this modified actuator was configured to be compact and lightweight… only 8 lbs. compared with the previous competitor’s model that weighted over 80 lbs.

An innovative mechanical gear arrangement was also incorporated that prevented over-travel and provided an additional measure of safety for the patient. In addition, a Modbus communications interface to the patient graphical controller was provided along with special software that met all requirements the new X10 design needed for the next generation machine.

Results:

The Kyntronics SMART Hydraulic Actuator (SHA) combines the power of hydraulics with the precision of servo control resulting in an actuation system that exceeded the Couch OEM’s force requirements while fitting into the constrained space available in the Couch mechanism. The SHAs quiet operation and compact packaging allowed the new Couch design to be used in field retrofits increasing the market opportunity for this OEM customer.