Evaluation of Wire Electrodes to Activate the Expiratory Muscles to Restore Cough

描述（由申请人提供）：本申请涉及广泛的挑战领域（06）使能技术和特定的挑战主题，06-NS-104：开发和验证辅助神经技术。呼吸系统并发症是脊髓损伤患者的主要发病率和死亡率，因为他们无法咳嗽和清除分泌物。这些人缺乏有效的咳嗽机制，因为他们的受伤往往导致几乎所有呼气肌肉的麻痹。因此，这些患者依赖于护理人员的帮助来应用手动抽吸、辅助咳嗽操作或其他气道管理方法。这些方法麻烦，通常不舒服，需要受过训练的人员，并且经常限制患者的活动性。由于大多数患者损伤水平以下的脊髓是完整的，脊髓运动神经元和外周神经肌肉装置保持功能。因此，呼气肌应服从功能性电刺激技术，以恢复有效的咳嗽机制。在一个单一的网站，试点研究四肢瘫痪的受试者，我们最近表明，呼气肌可以电激活脊髓刺激，一种方法，其中涉及通过椎板切开术切口的手术放置圆盘电极。电极定位在下胸椎和上腰椎节段的硬膜外背侧腔中。该研究的结果表明，该方法成功地实现了呼气肌激活的有效手段，如通过产生大气道压力和峰值气流速率所证明的。重要的是，这种技术有助于分泌物的清除，减少了对护理人员支持的需求，降低了呼吸道感染的发生率，提高了生活质量。因此，这种技术有可能降低医疗保健成本，提高脊髓损伤受试者的生存率。虽然成功，但由于电极放置所需的侵入性手术，许多脊髓损伤患者不愿意采用这种技术。然而，我们的假设是，呼气肌的类似激活可以用线电极实现，线电极可以通过针经皮插入，消除了对侵入性椎板切开术的需要，并且可以在门诊患者的基础上进行。后一种方法将增加患者和医生对该技术的接受度，缩短恢复时间并显著降低成本。因此，本研究的目的是直接比较线电极与先前采用的圆盘电极的功效。在6例接受永久性植入圆盘电极以恢复咳嗽的患者中，我们计划直接比较几种不同的金属丝电极系统与圆盘电极临时放置所实现的呼气肌激活程度。将通过监测手术室中使用不同电极系统进行电刺激期间实现的气道压力和峰值气流速率生成的变化来比较呼气肌激活的程度。本试验的结果将提供a）关于导致最佳呼气肌激活的线电极的尺寸和刺激配置的至关重要的数据，B）利用微创技术恢复咳嗽的其他人体研究的框架和c）可能修订我们的研究器械豁免（IDE）以通过脊髓刺激恢复咳嗽的必要数据，关于线电极的使用。 公共卫生相关性：由于他们不能咳嗽，呼吸系统并发症如肺炎是脊髓损伤受试者残疾和死亡的主要原因。本研究的目的是评价一种微创的呼气肌电激活方法，利用可经皮插入的脊髓丝电极恢复咳嗽。该技术可能会得到患者和医生的广泛接受，显著减少对护理人员支持的需求，促进呼吸道分泌物的管理，降低呼吸道感染的发生率，降低成本并改善该患者人群的生活质量。

DESCRIPTION (provided by applicant): This application addresses broad Challenge Area (06) Enabling Technologies and Specific Challenge Topic, 06-NS-104: Developing and validating assistive neuro-technologies. Respiratory complications account for significant morbidity and mortality in patients with spinal cord injury due to their inability to cough and clear secretions. These individuals lack an effective cough mechanism due to the fact that their injury often results in paralysis of virtually all of their expiratory muscles. Consequently these patients are dependent upon caregiver assistance for the application of manual suctioning, assisted coughing maneuvers or other methods of airway management. These methods are cumbersome, generally uncomfortable, require trained personnel and often restrict patient mobility. Since the spinal cord below the level of injury is intact in most patients, the motoneurons of the spinal cord and peripheral neuromuscular apparatus remain functional. Therefore, the expiratory muscles should be amenable to functional electrical stimulation techniques to restore an effective cough mechanism. In a single site, pilot study in tetraplegic subjects, we have recently shown that the expiratory muscles can be electrically activated by spinal cord stimulation, a method which involves the surgical placement of disc electrodes through laminotomy incisions. Electrodes are positioned in the dorsal epidural space at the lower thoracic and upper lumbar spinal levels. The results of this study indicate that this method is successful in achieving an effective means of expiratory muscle activation, as demonstrated by the generation of large airway pressures and peak airflow rates. Importantly, this technique facilitates secretion removal, reduces the need for caregiver support, reduces the incidence of respiratory tract infections and improves life quality. This technique therefore has the potential to reduce health care costs and improve survival in spinal cord injured subjects. While successful, many individuals with spinal cord injury are reluctant to pursue this technique due to the invasive procedure required for electrode placement. It is our hypothesis however that comparable activation of the expiratory muscles can be achieved with wire electrodes which can be inserted percutaneously through a needle, eliminating the need for the invasive laminotomy procedure and can be performed on an out-patient basis. This latter procedure would increase patient and physician acceptance of this technique, shorten recovery times and significantly reduce costs. The purpose of this undertaking therefore is to directly compare the efficacy of wire electrodes vs the previously employed disc electrodes. In 6 patients undergoing permanent implantation of disc electrodes to restore cough, we plan to directly compare the degree of expiratory muscle activation achieved with temporary placement of several different wire electrode systems with the disc electrodes. The degree of expiratory muscle activation will be compared by monitoring the changes in airway pressure and peak airflow rate generation achieved during electrical stimulation with different electrode systems in the Operating Room. The results of this trial will provide a) critically important data concerning the size and stimulus configuration of wire electrodes resulting in optimal expiratory muscle activation, b) the framework for additional human studies utilizing minimally invasive techniques to restore cough and c) necessary data for a possible amendment of our Investigational Device Exemption (IDE) to restore cough via spinal cord stimulation, with regard to use of wire electrodes. PUBLIC HEALTH RELEVANCE: Due to their inability to cough, respiratory complications such as pneumonia are a major cause of disability and death in subjects with spinal cord injury. The purpose of the proposed study is to evaluate a minimally invasive method of electrical activation of the expiratory muscles to restore cough utilizing spinal cord wire electrodes which can be inserted percutaneously. This technique would likely have wide patient and physician acceptance, significantly reduce the need for caregiver support, facilitate management of respiratory secretions, reduce the incidence of respiratory tract infections, reduce costs and improve life quality in this patient population.