Motorized Robotic Closed Cervical Traction

Abstract

Study Design. Biomechanical study Objective. To demonstrate that robotic cervical traction can apply closed cervical traction as effectively as manual weight-and-pulley traction in extension spring and cadaveric models. Summary of Background Data. Closed cervical traction is used to reduce subaxial cervical spine dislocation injuries and to distract the intervertebral space during cervical spine surgery. Weight-and-pulley cervical traction relies on cumbersome and imprecise technology without any safeguard to prevent over-traction or weights being pulled/released inadvertently. Methods. A prototype robotic traction device was designed and manufactured by the authors with real-time tensile force measurement, ±1-lbs (5 N) force application accuracy, locking/non-backdriveable linear actuators with actuator position sensing, 200-lbs (900 N) maximum force capability, up to 20° of flexion/extension manipulation, <25-lbs (111 N) device weight, and compatibility with Gardner-Wells tongs or Mayfield head clamp. The device was tested using an extension spring model and an intact fresh cadaver specimen to assess applied and desired force over time and radiographic changes in the cervical spine as traction force increased. The cadaver was tested in manual traction initially and then robotic traction in 10-lbs (50 N) increments up to 80-lbs (355 N) to compare methods. Results. The prototype device met or exceeded all requirements. In extension spring testing, the device reached the prescribed forces of both 25-lbs (111 N) and 80-lbs (355 N) accurately and maintained the desired weight. In cadaveric testing, radiographic outcomes were equivalent between the prototype and manual weight-and-pulley traction at 80-lbs (355 N; disk space measurements within ±10% for all levels), and the device reached the desired weight within±1-lbs (5 N) of accuracy at each weight interval. Conclusion. This preliminary work demonstrates that motorized robotic cervical traction can safely and effectively apply controlled traction forces.

A six degrees-of-freedom cable-driven robotic platform for head–neck movement

“…For example, as the head houses multiple important sensory organs such as vestibular and visual systems, there is growing interest in studying how human participants integrate and process these sensory inputs through techniques like applying directional force perturbations on the head 24 – 26 . Additionally, cervical deformity surgery and other spinal maneuvers require force and moment to be applied on the head to help achieve optimal cervical joint alignment and pain relief 27 . Because the proposed robotic system allows for full 6-DoF head–neck motion and force/moment application on the head, it can potentially be used in these applications with small design and control modifications.…”