VCSEL-based spectroscopy for next generation non-invasive and wearable glucose monitoring

该项目将医学院和物理学的研究人员与光电子学，光谱学和代谢生理学的专业知识相结合，开发先进的基于VCSEL的光谱学，旨在为糖尿病患者提供一种非侵入性可穿戴传感器用于血糖监测。项目结束时将对原型进行演示和测试，这是将设备集成到手表中的核心技术。基于该平台，我们的目标是进入可穿戴技术的研究，用于医疗和运动性能设置的血糖监测.非侵入性可穿戴医疗传感器能够提供快速和连续的实时监测生理变量越来越多的需求.这样的医疗传感器对于许多医疗状况的管理是关键的，糖尿病事实上，英国有400万人被诊断患有糖尿病1-约10%为1型糖尿病，其余为2型糖尿病，估计到2025年将增加到500万2。1型糖尿病患者每天使用侵入性针刺方法检测他们的血糖水平4到8次，以控制血糖水平并保持健康。一种方便的非侵入式血糖监测仪将彻底改变糖尿病患者的自我护理。连续血糖监测技术已经存在，但传感器需要皮下注射（即侵入式），寿命只有一到两周。这些传感器的不断更换使得这些设备的成本非常昂贵（大约3,000英镑/年）。如果我们能够开发出一种非侵入性的基于激光的技术，这将使更多的患者能够持续地管理他们的病情，从而减轻全球医疗服务提供者的负担，基于激光的光谱学被认为是最有前途的技术之一。然而，可穿戴技术会受到运动、汗水和温度的影响，这将显著影响日常使用中的激光精度。该项目旨在通过开发一种技术来克服这些挑战，该技术使用扫描操作的VCSEL对，该VCSEL对在850-1650 nm的近红外波段发射两个选择性中心波长，对水和葡萄糖具有强吸收。在1650 nm处发射的VCSEL具有挑战性，这将通过使用最近开发的基于GaSb衬底的数字合金和锑化物量子阱的先进量子材料来实现。通过特定的算法，该技术能够提供稳定和准确的血糖水平测量。优化激光器的波长、功率和光斑大小对于确保安全性至关重要，同时保持设备的质量和有效性。3年计划博士生将在博士学位的第一年和第二年开发基于激光的光谱技术和算法，用于分析葡萄糖水平。这项技术将在第3年转化为基于人体的试验，与（直接）静脉血糖测量和现有的有创连续血糖监测技术进行比较。该项目的管理团队由医学院和物理系的研究人员组成，为该技术的开发和人体试验提供了良好的基础。该项目是与Cascade technologies（CAS）合作的，后者专门从事气体传感的光谱仪器，飞鸿将提供特定波长的VCSEL。CAS将提供光谱设计和装置测试的咨询（随附支持信）。

This project combines researchers from the Medical School and Physics with expertise in optoelectronics,spectroscopy, and metabolic physiology, to develop advanced VCSEL-based spectroscopy aiming to provide a noninvasivewearable sensor for glucose monitoring for patients with diabetes. A prototype will be demonstrated andtested by the end of the project, which is the core technology for the devices to be integrated into watches. Basedon this platform, we aim to step into the research of wearable technologies for glucose monitoring in medical andsports-performance settings.Non-invasive wearable medical sensors capable of providing fast and continuous real-time monitoring ofphysiological variables are in increasing demand. Such medical sensors are pivotal for the management ofnumerous medical conditions, e.g., diabetes. Indeed, 4 million people in the UK have been diagnosed withdiabetes1 - about 10% with type 1, and the remainder with type 2, which is estimated to increase to 5 million in20252. People with type 1 diabetes test their blood-sugar levels four to eight times a day, using invasive needleprickmethods, in order to manage blood sugar levels and maintain their health. A convenient and non-invasiveglucose monitor would revolutionise patient self-care for diabetes.Continuous glucose monitor technology exists but sensors require subcutaneous injection (i.e. are invasive) andhave a lifespan of only one to two weeks. Constant replacement of these sensors makes the cost of these devicesprohibitively expensive (circa £3,000/year). If we are able to develop a non-invasive laser-based technology, thiswould allow more patients to manage their condition continuously and thus reduce the burden on globalhealthcare providers.Laser-based spectroscopy has been proposed as one the most promising techniques for this purpose. However,wearable technologies are influenced by movement, sweat, and temperature, which would significantly affectlaser accuracy in everyday use. This project aims to overcome these challenges through developing a technologythat uses swept operated VCSEL pairs that emit at two selective central wavelengths in near infrared band of 850-1650 nm, which have strong absorption to water and glucose. The VCSEL emitting at 1650nm is challenging, thiswill be achieved through the use of advanced quantum materials of digital alloy and antimonide quantum wellsbased on GaSb substrate, which were developed recently3. With a specific algorithm, this technique is able toprovide stable and accurate measuring of the level of glucose in blood. Optimising the wavelengths, power, andspot size of the lasers will be vital to ensure safety as a priority, while maintaining quality and effectiveness of thedevice.3-year planThe PhD student will develop the laser-based spectroscopy technology and algorithms for analysis of glucoselevels in year one and two of the PhD. This technology will then be translated into human-based trials comparingto (direct) venous blood glucose measurement and existing invasive continuous glucose monitor technology inYear 3. The supervisory team consists of researchers in the Medical School and the Department of Physics andprovides an excellent basis upon which to help develop this technology and test in human trials.The project is a collaboration with Cascade technologies (CAS), who specialise in spectroscopic instrumentationfor gas sensing and Feihong will provide the VCSELs with specified wavelengths. CAS will provide consultancy ofthe design of the spectroscopy and test of our setup (Letter of Support enclosed).