Analog Devices' Data Acquisition Chip enhances CT Scanners

The ADAS1128 is a 24-bit current-to-digital converter that changes photodiode array signals into digital signals. The product offers 128 data conversion channels, provides an unparalleled increase in speed from 6kSPS (kilosamples per second) to 20kSPS, and supports four times more channels (128 versus 32) than any other integrated converter solution available on the market today. This level of performance and integration means a 50 percent reduction of a CT detection system’s electronics cost versus older designs.



“Higher slice count CT systems require an increase in the number of data acquisition channels necessary to process images. The level of integration of ADI’s ADAS1128 chip will enable lower cost CT systems by reducing the cost per channel of the data acquisition circuits, said Bernard Gordon, chairman of NeuroLogica Corporation, a provider of medical imaging equipment for healthcare facilities and private practices worldwide. A prominent pioneer in the medical imaging industry, Gordon is also the founder and former CEO of Analogic Corporation, a leading designer and manufacturer of advanced health and security systems and subsystems sold primarily to Original Equipment Manufacturers (OEMs).



CT imaging combines special X-ray equipment with sophisticated computers to produce internal 2D and 3D images of the human body. CT scans of internal organs, bone, soft tissue, and blood vessels provide more detailed images than X-ray exams, enabling physicians to more easily diagnose problems that include cancer, cardiovascular disease, and musculoskeletal disorders. Today, it is estimated that more than 62 million medical CT scans are done in the United States annually, compared to three million in 1980.



“A higher slice count is one of the principal factors that enable current CT scanners to provide more detailed images,” said Patrick O’Doherty, healthcare segment director, Analog Devices. “With the ADAS1128, diagnostic system designers can develop CT scanners that produce clearer images while reducing overall scan time compared with older machines. This is invaluable in critical care areas, such as cardiology, neurology, and angiography. The dramatic system-level cost, size, and power savings resulting from the ADAS1128 means that world-class CT scan diagnostics will become more affordable and practical in medical and security-sensitive environments throughout the world.”



“Advancements in CT scan imaging will fundamentally change the practice and economics of diagnostic imaging,” said Susie Inouye, research director, Databeans, Inc., a leading semiconductor research firm. “Current-to-digital converters that offer higher levels of channel integration will play a vital role in the design of next-generation CT scanners. By quadrupling the number of data conversion channels, ADI’s new current-to-digital converter is setting a new performance benchmark for CT detection system designs.”



The ADAS1128 replaces previous converter-based technology having low levels of channel integration. The product integrates a 24-bit resolution ADC (analog-to-digital converter) with 128 simultaneously sampled data converter channels, selectable sample rates up to 20kSPS, and on-chip temperature sensor and reference buffer into a 1 cm2 single-chip solution. Along with supporting four times more channels, the product delivers over three times the throughput of any other solution available on the market.



The ADAS1128 consumes less than half the power of other solutions (4.5 mW/channel versus 10 mW/channel at full speed). It also offers superior overall performance specs, such as no charge loss, more choices of full scale ranges, and ultra-low noise (down to 0.4 fC for low-dose X-ray systems).



Other recent medical announcements from ADI include the award-wining AD927x family of eight-channel (octal) receivers for ultrasound systems. These products, along with other ADI offerings, represent today’s broadest IC product portfolio geared specifically toward the healthcare imaging market.