Experimental measurement of force, torque control and vibration absorber system for intraoperative tele-operated robotic-assisted femoral shaft drilling using air-controlled soft balloon damper

摘要

The use of closed intramedullary nailing fixation and drilling technique is a very common, safe and standard method for treating diaphyseal femoral fractures. However, it has several demerits such as high cutting forces and torque during drilling and this could cause high vibration and result in cracks, tool breakage and necrosis of the already fractured bone. This paper presents the measure of force, torque control and vibration absorber system for intra-operative tele-operated robotic-assisted femoral shaft drilling using air-controlled balloon damper experimentally, since bone is surrounded by soft tissues that can cause more severe injury to the tissue due to high traction force. Simulated femur bone and tissue are used for this experiment. A sensor-based model clamping system embedded with controlled pressurized air balloon to damp drilling vibration was developed; the drilling forces were monitored by the force sensor attached to the end robot effector, while the resulted vibration was measured by contact sensor during the entire surgical drilling. Forces and vibration caused by drilling forces acting on the bone at varying damper pressure at varying spindle drill speed were obtained using (EMS 309 data acquisition and then the data were processed using MATLAB R2015b. The vibration results were processed with wavelet packet transform (WPT) using Fast Fourier transform to analyze the vibration signals, frequencies and amplitude of the vibration. This modeled control system is a good concept, results clearly justify that soft clamping fixation system can be employed to reduce force, torque and vibration without causing harm to the delicate surrounding tissues. This control measures can provide surgeons with real-time information which can assist them in repositioning and repair of fracture bone within control and safe margins. It is believed that this idea will have greater future developmental prospect.