Hyperspectral Compressive Sensing Spectrometer for Adult Neuromonitoring in Cardiac Surgery

心脏手术是一项挽救生命的手术，但也有脑损伤的高风险。如今，在加拿大每年接受心脏手术的4万名患者中，有3-6%的人会遭受严重的脑损伤，主要是由于手术导致的脑部血流量不足（脑缺血）。不幸的是，目前还没有能够可靠地检测心脏手术中成人脑缺血的无创神经监测仪。我们之前开发了一种安全的近红外光谱（NIRS）技术，可以通过监测细胞色素-c氧化酶（oxCCO）的氧化还原状态来检测新生儿脑缺血，oxCCO是线粒体中的一种跨膜蛋白，对脑缺血高度敏感。这种便携式设备将是理想的神经监测设备；然而，将这项技术扩展到成年人身上仍然是一个未遇到的挑战，因为他们的头骨很厚。我们的目标是开发一种近红外光谱技术，可以无创地监测成人大脑中的oxCCO，并证明在接受心脏手术的患者中获得这些测量值的可行性。我们将建立一个时间分辨的近红外装置，可以测量几十个波长的深层组织吸收，如oxCCO测量所需。短脉冲光（持续时间为皮秒）将被送入组织，光子的飞行时间将使用先进的量子探测技术进行精确测量。我们将选择在激光脉冲很久之后到达探测器的光子，因为它们在头部深处传播，并且很有可能探测到大脑。这一点很重要，因为非侵入性光学探头将被放置在皮肤上，光线在到达大脑之前必须穿过头皮和厚（10毫米）的成人头骨。为了满足设备的严格技术要求，告知其设计并验证它，我们组建了一个跨学科团队，他们在生物医学设备开发，量子传感和新技术的临床应用方面具有专业知识，以改善患者的预后。为了培训加拿大未来的科学工作人员，将招募三名研究生，使用当前EDI的最佳实践，并培训他们在临床中开发、验证和使用该设备。这一提议将导致一种技术的发展，这种技术可以减少心脏手术相关脑损伤的发生率，并使这种常见的外科手术更安全，因为全世界每年有100万人接受这种手术。

Cardiac surgery is a life-saving operation but carries a high-risk of brain injury. Today, 3-6% of the 40,000/year patients undergoing heart surgery in Canada will suffer from serious brain injury, mainly caused by inadequate blood flow to the brain (cerebral ischemia) resulting from the operation. Unfortunately, there is currently no noninvasive neuromonitor that can reliably detect adult cerebral ischemia in cardiac surgery.We previously developed a safe near-infrared spectroscopy (NIRS) technique that can detect cerebral ischemia in neonates by monitoring the redox state of cytochrome-c-oxidase (oxCCO) - a transmembrane protein in the mitochondria that is highly sensitive to cerebral ischemia. Such a portable device would be ideal for neuromonitoring; however, extending the technique to adults remains an unmet challenge because of their thick skull.Our objective is to develop a NIRS technique that can noninvasively monitor oxCCO in the adult brain and demonstrate the feasibility of acquiring these measurements in patients undergoing heart surgery.We will build a time-resolved NIRS device that can measure deep-tissue absorption at several dozens of wavelengths, as required for oxCCO measurement. Short pulses of light (picosecond in duration) will be sent into tissue and the time-of-flight of the photons will be precisely measured using advanced quantum detection. We will select photons that arrive at the detector long after the laser pulse, as they travelled deep in the head and have a high probability of probing the brain. This is important because the noninvasive optical probes will be placed on the skin and light must travel through the scalp and thick (10 mm) adult skull before reaching the brain.To meet the stringent technical requirements of the device, inform its design, and validate it, we have assembled an interdisciplinary team with expertise in biomedical device development, quantum sensing, and clinical applications of novel technologies to improve patient outcome. To train Canada's future scientific workforce, three graduate students will be recruited, using current best practices in EDI, and trained to develop, validate, and use the device in the clinic. This proposal will lead to the development of a technique that could reduce the incidence of heart surgery related brain injuries and make this common surgical operation safer for the 1 million people who undergo it around the world every year.