Low-cost handheld medical device for neuroaxial anesthesia guidance in the obese

描述（由申请人提供）：目前神经轴麻醉程序（即硬膜外麻醉和脊髓麻醉）的护理标准是手动触诊脊柱骨标记，然后“盲”针头插入。然而，在肥胖人群中，估计约占美国总人口的33.9%，脊柱骨地标被厚厚的脂肪层覆盖，无法通过触诊检测到。因此，手术失败率很高（40% - 80%），导致许多健康并发症：头痛、血肿、背痛、血管穿刺、胸膜穿刺、气胸和瘫痪。盲法的替代方法包括透视和超声引导。透视缺乏便携性，成本较高，并使患者暴露于电离辐射。最近的研究表明，常规超声可以提高成功率（例如，从32%提高到65%）。然而，由于骨超声图像质量差，失败率仍然很高。需要新的医疗设备技术来克服标准超声的局限性，提高肥胖患者的神经轴麻醉成功率。这个第一阶段的提案寻求资金支持一种低成本的手持式医疗设备的开发和可行性测试，用于肥胖患者的神经轴麻醉指导。该项目的关键技术创新包括具有少量单元件换能器和多模态位置传感的超声系统，由于设备成本降低，便携性更高，并且减轻了离轴反射伪影，因此在技术上优于标准超声系统。此外，本项目还包括一种基于主动形状模型的骨表面位置估计方法，用于自动识别针头插入位置，比单独使用标准超声更直观地进行图像解释。该项目的长期目标是将一种便携式、低成本、基于超声的医疗设备商业化，以降低神经轴向麻醉过程中不良健康结果的风险。本研究的第一阶段假设是开发一种低成本的手持式超声医学成像设备，并在离体骨、组织和体脂模拟模拟实验中，在图像深度达10厘米的情况下，实现优于2.5毫米的骨图像分辨率。将展示一个具有实时图像显示和电子信噪比（SNR）的功能性手持式超声原型，图像深度为10 cm，来自骨骼> 15 dB。此外，基于模型的脊柱骨骼解剖位置估计技术将在模拟中开发，该设备将在离体模拟实验中进行实验验证，以证明成像分辨率< 2.5 mm。第二阶段的研究计划包括工业设计、软件和用户界面开发，以及在弗吉尼亚大学医院进行体内试验研究。据估计，美国每年进行1800万例手术，估计美国市场规模约为2.08亿美元/年，全球市场规模为5.66亿美元/年。

DESCRIPTION (provided by applicant): The current standard of care for neuroaxial anesthesia procedures (i.e. epidural and spinal anesthesia) is manual palpation of spinal bone landmarks followed by "blind" needle insertion. However, in the obese segment of the population, estimated at approximately 33.9% of the total US population, spinal bone landmarks are covered with thick layers of fat and are not detectable via palpation. As a result, procedure failures occur at high rates (i.e. 40% - 80%) resulting in numerous health complications: headache, hematoma, backpain, vascular puncture, pleural puncture, pneumothorax, and paralysis. Alternative approaches to the blind method include fluoroscopy and ultrasound guidance. Fluoroscopy lacks portability, has a higher cost, and exposes the patient to ionizing radiation. Recent studies have shown that conventional ultrasound improves success rates (e.g. 65% from 32%). However, failure rates remain high due to poor image quality of bone with ultrasound. New medical device technology is needed to overcome limitations of standard ultrasound and improve neuroaxial anesthesia success rates in the obese. This Phase I proposal seeks funding to support the development and feasibility testing of a low-cost, handheld medical device for neuroaxial anesthesia guidance in the obese. Key technological innovations of this project include an ultrasound system with a low number of single-element transducers and multi-modality position sensing, which is technologically advanced over standard ultrasound due to reduced device cost, greater portability, and mitigation of off-axis reflection artifacts. In addition, this project includes an active shape model-based bone surface position estimation method for automated identification of needle insertion location, which enables more intuitive image interpretation than with standard ultrasound alone. The long-term goal of the proposed project is to commercialize a portable, low-cost, ultrasound-based medical device to lower the risk of adverse health outcomes from neuroaxial anesthesia procedures. The Phase I hypothesis of the proposed research is that a low-cost handheld ultrasound-based medical imaging device can be developed and demonstrated to achieve bone image resolution better than 2.5 mm at image depths up to 10 cm in ex vivo bone, tissue, and body fat-mimicking phantom experiments. A functional handheld ultrasound prototype with real-time image display and electronic signal-to-noise ratio (SNR) from bone > 15 dB at image depths of 10 cm will be demonstrated. In addition, model-based spinal bone anatomy position estimation techniques will be developed in simulation and the device will be experimentally validated in ex vivo phantom experiments to demonstrate imaging resolution < 2.5 mm. Research plans for Phase II include industrial design, software and user interface development, and an in vivo pilot study at the University of Virginia Hospital. With an estimated 18 million procedures performed in the US per year, the estimated US market size is approximately $208 M/yr with a worldwide market of $566 M/yr. PUBLIC HEALTH RELEVANCE: The current standard of care for neuroaxial anesthesia procedures includes blind needle insertion based on manual palpation of spinal bone landmarks. Failures occur at high rates (i.e. 40% - 80%) in the obese where landmarks are impalpable, which results in numerous health complications: headache, hematoma, back pain, vascular puncture, pleural puncture, pneumothorax, and paralysis. The long-term goal of this project is to demonstrate a portable, low-cost, ultrasound-based medical device that facilitates neuroaxial anesthesia in the obese, improves success rates, and lowers the risk of associated health complications.