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

描述（由申请人提供）：神经轴向麻醉手术（即硬膜外麻醉和脊髓麻醉）的当前护理标准是手动触诊脊柱骨标志，然后进行“盲”针插入。然而，在肥胖人群中，估计约占美国总人口的33.9%，脊柱骨标志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（即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荧光透视和超声引导。荧光透视检查缺乏便携性，成本较高，并且使患者暴露于电离辐射。最近的研究表明，常规超声提高了成功率（例如，从32%提高到65%）。然而，由于超声骨图像质量差，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并提高肥胖患者的神经轴向麻醉成功率。 该第一阶段提案寻求资金，以支持开发和可行性测试的低成本，手持医疗设备的神经轴向麻醉指导肥胖。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感测的超声系统，由于降低了设备成本、更高的便携性和减轻了离轴反射伪影，该系统在技术上优于标准超声。此外，该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，与单独使用标准超声相比，该方法可以实现更直观的图像解释。拟议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手术造成不良健康后果的风险。 拟议研究的第一阶段假设是，可以开发并证明一种低成本的手持式超声医学成像设备，在离体骨骼、组织和身体脂肪模拟体模实验中，在图像深度高达10 cm时，骨图像分辨率优于2.5 mm。将演示一种功能性手持式超声原型，该原型具有实时图像显示和来自骨的电子信噪比（SNR）> 15 dB，图像深度为10 cm。此外，基于模型的脊柱骨解剖位置估计技术将在模拟中开发，该设备将在体外体模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的体内试验研究。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。 公共卫生相关性：当前的神经轴向麻醉手术护理标准包括基于脊柱标志的手动触诊的盲针插入。肥胖患者的失败率很高（即40% - 80%），其中标志无法触及，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。该项目的长期目标是展示一种便携式，低成本，基于超声的医疗设备，有助于肥胖患者的神经轴向麻醉，提高成功率，并降低相关健康并发症的风险。

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.