Aszmann O C, Dietl H, Frey M
Abteilung für Plastische und Rekonstruktive Chirurgie, Medizinische Universität Wien, Währinger Gürtel 18-20, Vienna, Austria.
Handchir Mikrochir Plast Chir. 2008 Feb;40(1):60-5. doi: 10.1055/s-2007-989415.
To date, the movement of myoelectrical arm prostheses proceeds via two transcutaneous electrodes that are controlled by two separately innervated muscle groups. The various control levels are chosen by co-contractions of these muscles and the respective level is linearly controlled by the same muscles. A harmonious course of movement as in the corresponding natural pattern of motion is not possible in this way. An appreciable improvement would be given by the control of the individual movement levels by signals that correspond neuronally with the natural pattern of motion. Just recently, prostheses with six control levels have been realised technically. The objective is to separate the major arm nerves, such as the musculocutaneous nerve, radial nerve, median nerve and ulnar nerve, from the proximal arm nerve plexus and to transfer them to the residual nerve branches of muscles near the stem in order to create meaningful neuromuscular units that can serve as impulse sources for myoelectrical prosthesis. As target muscles, above all, one can consider the major/minor pectoral muscles or, respectively, the latissimus muscle. According to the activity of the donor nerves, these muscles would contract and control the prosthesis via transcutaneous electrode. In this way, a harmonious control corresponding intuitively to the natural pattern of movement would be possible without the necessity for the patient to continuously switch between the various control levels. Prerequisites for this are intact proximal muscle groups and a more or less intact arm nerve plexus with the possibility to isolate donor nerves according to the topographic-anatomic situation. For this reason, a preoperative MRI examination, a high resolution sonographic study and balancing NLG and EMG of the residual nerve plexus are necessary. For the preoperative planning phase as well as for the postoperative follow-up, a detailed procedure has been established, in cooperation with the innovation department of the Otto Bock company, to create the most meaningful switch levels, to optimise electrode placement as well as to clarify prosthesis incorporation. Finally, a complex rehabilitation programme is necessary for the patient to achieve an optimal result.
迄今为止，肌电手臂假肢的运动是通过两个经皮电极进行的，这两个电极由两个分别受神经支配的肌肉群控制。通过这些肌肉的共同收缩来选择不同的控制水平，并且相应的水平由相同的肌肉进行线性控制。以这种方式不可能实现如相应自然运动模式那样和谐的运动过程。通过与自然运动模式在神经上相对应的信号来控制各个运动水平，将会有显著的改善。就在最近，技术上已经实现了具有六个控制水平的假肢。目标是将主要的手臂神经，如肌皮神经、桡神经、正中神经和尺神经，从近端臂神经丛中分离出来，并将它们转移到靠近残肢的肌肉的残余神经分支处，以便创建有意义的神经肌肉单元，这些单元可以作为肌电假肢的脉冲源。作为目标肌肉，首先可以考虑胸大肌/胸小肌，或者背阔肌。根据供体神经的活动，这些肌肉会收缩，并通过经皮电极控制假肢。通过这种方式，就有可能实现与自然运动模式直观对应的和谐控制，而无需患者在不同的控制水平之间持续切换。这样做的前提是近端肌肉群完好无损，并且臂神经丛或多或少完好无损，有可能根据地形解剖情况分离供体神经。因此，术前进行MRI检查、高分辨率超声研究以及对残余神经丛进行神经传导速度测定（NLG）和肌电图（EMG）平衡是必要的。为了术前规划阶段以及术后随访，已经与奥托博克公司创新部门合作制定了详细的程序，以创建最有意义的切换水平、优化电极放置以及明确假肢的植入情况。最后，患者需要一个复杂的康复计划来达到最佳效果。
