We have developed a new lens measurement system (LMS) that simultaneously measures the intensities of fluorescence and Rayleigh components at various distances into the lens along the optical axis. The noninvasive measurement is performed through an undilated pupil, and with the assistance of a pupil tracking system that facilitates maintaining the x and y positions of the sample volume (ca. 300 m in length, 600 m high, and 80 m wide) to within Ϯ100 m of any programmed ''lock'' position. The intensity of the Rayleigh component that is used to normalize the measured fluorescent signal serves to correct the attenuation effects due to absorption and lens light scatter (Mie-Tyndall type). This report, resulting from a SpectRx Site L clinical study using a refined instrumentation (SpecRx Scan V), presents analysis of fluorescence and Rayleigh data from the lenses of 923 controls and 239 diabetic subjects (45 Type I and 194 Type II) ranging from 23 to 75 years old. Fluorescence and Rayleigh data have been obtained via confocal mode from various locations nominally along the lens optical axis (the true trajectory of a sample volume could be shown in a figure) for controls and diabetics, at different ages, using three pairs of excitation and collection wavelengths: 364/495 nm, 434/495 nm, and 485/515 nm. For control subjects, there exists a strong, almost linear relationship between age and fluorescence, while diabetic subjects tend to deviate from this age-fluorescence relationship. Our data show that the lenses of diabetic patients are subject to an accelerated aging process, presumably due to an elevated level of brown and fluorescent protein adducts and crosslinks from nonenzymatic glycosylation (Maillard-Amadori reactions). We have also shown that by using the measured Rayleigh profiles to normalize the measured fluorescence, most of the absorption effects are removed and therefore the separation between the fluorescence of diabetics and controls is greatly improved. Thus, the device for measuring fluorescence/Rayleigh ratios can be used to noninvasively screen populations for possible undiagnosed diabetes.

The MicroSensors Systems (MSS) Program is developing a layered sensor network to detect dismounted threats approaching high value assets. The MSS subsystem elements include sensitive receivers (capable of detecting << 1 Watt emissions in dense signal or degraded signal environments) and low power, miniature, disposable sensors (acoustic, magnetic, and infrared). A novel network protocol has been developed to reduce the network traffic resulting in conservation of system power and lower probability of detection and interception. The MSS program will provide unprecedented levels of real-time battlefield information, greatly enhancing combat situational awareness when integrated with the existing Command, Control, Communications, Computers, Intelligence, Surveillance and Reconnaissance (C4ISR) infrastructure. This system will provide an important boost to realizing the information dominant, network-centric objective of Joint Vision 2020. The program has established two Centers of Excellence for Sensor Technology each of which is capable of designing and building next generation, networked microsensor systems. The Defense Microelectronics Activity has teamed with the Centers of Excellence and industry to preserve long-term Department ofDefense access to key next generation manufacturing technologies.The military's current battlefield sensor technology falls short in its ability to detect dismounted threats. To date, the current sensor systems lack the ability to identify a dismounted threat, which results in high false alarm rates, as well as have costs that prohibit the deployment of a large sensor field. The Defense Microelectronics Activity (DMEA) is managing a four-year program, MicroSensors Systems (MSS), to develop a low-cost, disposable, networked microsensor system that is focused on detecting dismounted threats. MSS aims to have a sensor cost of $25, which will allow the deployment of large sensor networks. MSS also has many potential applications in military, government, and commercial sectors.A major focus of the program has been to use commercial off-the-shelf (COTS) electronics and high density, low cost assembly methodologies. Selection of the appropriate COTS microelectronics was profoundly influenced by the need to exploit all possible low power techniques and technologies to ensure a reasonable sensor and hub service life. The MSS design attempts to limit the power consumption of the system to achieve the goal of a 14-day or longer mission life. Other applications and concept of operations (CONOPS) require optimization of other system-level features, resulting in system performance variations in terms of signal processing speed, communication range and service life.The program has established two Centers of Excellence (COEs) for sensor technology at the University of Alaska Fairbanks and North Dakota State University. These centers are designing and building the next generation, networked microsensor systems as well as developing new technologies that enable cost and size reduction of the sensors. DM...

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