Gebai Sarah, Hammoud Mohammad, Hallal Ali, Khachfe Hassan
Department of Mechanical Engineering, Lebanese International University, Beirut, Lebanon.
Department of Biomedical Engineering, Lebanese International University, Beirut, Lebanon.
Bioengineering (Basel). 2016 Jul 5;3(3):18. doi: 10.3390/bioengineering3030018.
Parkinson's patients suffer from severe tremor due to an abnormality in their central oscillator. Medications used to decrease involuntary antagonistic muscles contraction can threaten their life. However, mechanical vibration absorbers can be used as an alternative treatment. The objective of this study is to provide a dynamic modeling of the human hand that describes the biodynamic response of Parkinson's patients and to design an effective tuned vibration absorber able to suppress their pathological tremor. The hand is modeled as a three degrees-of-freedom (DOF) system describing the flexion motion at the proximal joints on the horizontal plane. Resting tremor is modeled as dual harmonic excitation due to shoulder and elbow muscle activation operating at resonance frequencies. The performance of the single dynamic vibration absorber (DVA) is studied when attached to the forearm and compared with the dual DVA tuned at both excitation frequencies. Equations of motion are derived and solved using the complex transfer function of the non-Lagrangian system. The absorber's systems are designed as a stainless steel alloy cantilevered beam with an attached copper mass. The dual DVA was the most efficient absorber which reduces 98.3%-99.5%, 97.0%-97.3% and 97.4%-97.5% of the Parkinson's tremor amplitude at the shoulder, elbow and wrist joint.
帕金森病患者由于其中心振荡器异常而遭受严重震颤。用于减少不自主拮抗肌收缩的药物可能会危及他们的生命。然而，机械振动吸收器可以用作替代治疗方法。本研究的目的是提供一种描述帕金森病患者生物动力学反应的人手动态模型，并设计一种能够抑制其病理性震颤的有效调谐振动吸收器。手被建模为一个三自由度（DOF）系统，描述水平面上近端关节处的屈曲运动。静止性震颤被建模为由于肩部和肘部肌肉在共振频率下激活而产生的双谐波激励。研究了单动态振动吸收器（DVA）附着在前臂时的性能，并与在两个激励频率下调谐的双DVA进行了比较。使用非拉格朗日系统的复传递函数推导并求解运动方程。吸收器系统设计为带有附加铜块的不锈钢合金悬臂梁。双DVA是最有效的吸收器，可将帕金森病患者在肩部、肘部和腕关节处的震颤幅度降低98.3%-99.5%、97.0%-97.
