| | | The use of sensors in medical deuces has been increasing and will continue to do so with newer technologies. As such, learning more about the specifics of these components is essential for designers to be successful and provide the greatest array of capabilities in their products. This article looks specifically at image sensors and provides an excellent overview of the technology. By Niels Wartenherg Like most electronic devices, image sensors are smaller, faster, and far more economical than they were even a few years ago. The capabilities of image sensors today have dramatically increased, due in large part to the advancements of megapixel technology. Depending upon the application, engineers could replace four to ten sensors inside their device with a single megapixel unit, reducing the complexity of the device's design while also lowering its total cost of ownership (Figure 1). Imagers and other sensors are one of the most important components for ensuring accuracy of instrumentation. They can also be one of the most expensive. It is important to understand the key differences among the types of imagers available, (he performance and value (hey provide, and their ease of integration Image Sensor Technology Advancements To understand the performance advantages and application opportunities megapixel imagers provide, careful review ol imaging technology options and the limitations of each is recommended. Laser scanners have historically been (lie most common type of data collection device embedded into medical devices. While laser has a distinct speed advantage, i( is unlikely to remain the most commonly used technology because it is limited to strictly reading bar codes, where as an imager can perform a broader range of functions (Figure 2). An image sensor is a device that converts a visual image into an electric signal. Image sensors rely on a variety of technologies to perform this, but the majority use an array of CCD (charge-coupled device) or CMOS (complementary-metal oxide semiconductor) sensors such as active-pixel sensors. CCD-based imagers typically perform faster and collect light more efficiently. In general, they are often recommended for challenging, very low contrast or high-speed applications. CMOS sensors are usually less costly to manufacture and therefore provide a more cost-efficient solution. In the past, there has been a trade-off between cost and performance. However, CMOS technology has improved so rapidly, that some sensors today rival the performance ol CCDs. | | |