I-Corps: Sensing device to prevent and control glaucoma

青光眼是一组可以损害眼睛视神经并导致视力丧失和失明的疾病。一半患有青光眼的美国人不知道自己的病情。这是因为青光眼患者通常不会出现任何症状，直到出现无法弥补的损害。专业诊断的困难加剧了这个问题。参加所有推荐的眼科健康检查的患者将每1-2年看一次眼科医生，届时他们将接受眼压检查以检查青光眼。眼压测试只测量一次眼压，但如果患者的眼压在每年的检查中波动到较低的水平，青光眼可能不会被发现。此外，在两次访问之间的长时间间隔内，可能会发生不可逆转的损害和失明。与视力受损和失明美国人的护理相关的成本负担来自政府机构（医疗保险，特别是医疗补助），以及来自私人保险公司的额外13亿美元，以及老年人及其家庭的57亿美元自付费用。该项目旨在开发一种解决方案，通过升级目前用于白内障的植入晶体，为患青光眼风险较高的患者提供移动和持续监测。监测是通过病人在靠近眼睛的地方放置一个外部读出装置来完成的。这一简单的附加产品和程序将降低青光眼患者失明的发生率和程度，并将降低由青光眼引起的不可逆眼睛损伤的相关费用。正在开发的产品是一个由眼压传感器和相关的实时报告眼压的读取系统组成的系统。该产品实际上是由压力传感器和读取器组成的双组份系统。植入式压力传感器完全由生物相容性材料制成，形成共振结构，随着眼睛内压力的变化而改变共振频率。该传感器嵌入或层压在目前用于白内障手术的人工晶体上。传感器不包含电源或内部电路，因此它不容易失效或过时。此外，没有有害物质进入眼睛。相关的读取器通过发射低功率射频（RF）信号远程询问（ping）谐振传感器，并监测传感器反射的信号。压力的变化会使读取器读取到不同的响应频率。阅读器系统将经常跟踪压力变化以提供趋势，并在压力增加到可能永久性损伤视神经的水平时向患者和/或医生发出警报。其目的是创建一个简单的阅读器，它可以是一个独立的设备，一个使用智能手机的附加硬件，或者一个可穿戴健康监测系统的子系统。该提案的范围是完成可批量生产的压力传感器的开发，阅读器原型的开发，以及系统的鲁棒性测试，最值得注意的是确定射频链路的限制，传感器植入可靠性，以及潜在的传感器漂移或校准问题。该产品是使用无源射频传感器和外部读取器远程监测身体状况的许多潜在系统中的第一个。

Glaucoma is a group of diseases that can damage the eye's optic nerve and result in vision loss and blindness. Half of Americans living with glaucoma are unaware of their condition. This is because glaucoma sufferers often do not experience any symptoms until irreparable damage has occurred. Adding to this problem is the difficulty of professional diagnosis. Patients who attend all recommended eye wellness exams will see an ophthalmologist every 1-2 years, at which time they will receive a tonometry exam to check for glaucoma. A tonometry test takes a single measurement of the eye pressure, but glaucoma may remain undetected if the patient's pressure happened to fluctuate to the low end during the annual visit. In addition, irreversible damage and blindness could occur during the long time span between visits. The cost burden associated with nursing care for visually impaired and blind Americans amounts to $13.2 billion from government agencies (Medicare, Medicaid specifically), as well as an additional $1.3 billion from private insurance companies, and $5.7 billion in out-of-pocket expenses for seniors and their families. This project aims to develop a solution that offers mobile and continuous monitoring for patients at higher risk of developing glaucoma by upgrading currently implanted lenses for cataracts. Monitoring is performed by the patient placing an external readout unit in proximity to the eye. This simple add-on to an existing product and procedure will reduce the incidence and extent of blindness in glaucoma patients, and will decrease the costs associated with irreversible eye damage caused by glaucoma.The product being developed is a system that is comprised of an intraocular pressure sensor and an associated reader system that reports intraocular pressure in real-time. The product is really a two-component system formed of the pressure sensor and reader. The implantable pressure sensor is solely fabricated of biocompatible materials that form a resonating structure that changes in resonant frequency as the pressure in the eye varies. The sensor is embedded or laminated on current prosthetic lenses used in cataract surgeries. The sensor contains no power supply or internal circuit, hence it does not easily fail or get out of date. In addition, no hazardous materials are introduced in the eye. The associated reader remotely interrogates (pings) the resonant sensors by emitting a low power radio frequency (RF) signal and monitors the reflected signal from the sensor. Changes in pressure will cause the reader to read different response frequencies. The reader system will track pressure variation frequently to provide trends and will alert the patient and/or physician if the pressure increases to levels that can permanently damage the optic nerve. The intent is to create a simple reader that can be a standalone device, an add-on piece of hardware using smart phones, or a sub-system addition to wearable health monitoring systems. The scope of this proposal is to complete the development of mass producible pressure sensors, development of a reader prototype, and robustness testing of the system, most notably identifying limitations on the RF link, sensor implant reliability, and potential sensor drift or calibration issues. This product is the first of many potential systems for remotely monitoring conditions in the body using the passive RF sensors and with external readers.