Low-noise circuitry is critical to image quality of medical ultrasound; an indispensable diagnostic tool. Despite the conceptual simplicity of the underlying principle, a complete, high-end ultrasound imaging system is a complicated device (Figure 1). The ultimate performance of the system is largely determined by the transducer and analog front end (AFE), while post-processing of the […]
Minimizing electrical noise to improve medical-ultrasound images, Part 1
Low-noise circuitry is critical to the image quality of medical ultrasound, an indispensable diagnostic tool. Ultrasound technology, a widely used non-invasive tool in medical diagnostics and other applications, has shifted from static to dynamic images and from black-and-white to color Doppler images. These important enhancements are largely due to the introduction of digital ultrasound technology […]
When reality intrudes on component models and equivalent circuits
Determining the utility of an equivalent-circuit model versus construction reality is often a difficult challenge. Using simplified, first-order approximations in models and equivalent circuits is a normal part of engineering life. Without them, we would get mired in the details and harsh reality of the components and their characteristics. We would never be able to […]
RFID upgrade pushes “ancient” pneumatic-tube system into the 21st century: Part 2
Adding simple RFID tags to hospitals’ widely used pneumatic-tube systems has dramatically improved performance without needing a system rebuild. Wireless solves the problem — and does more Modern electronic technology has reinvigorated the pneumatic tube system to do more and do better without requiring more tube pathways. This can apply to upgrading an existing installed […]
RFID upgrade pushes “ancient” pneumatic-tube system into the 21st century: Part 1
The addition of simple RFID tags to hospitals’ widely used pneumatic tube system has dramatically improved performance without needing a system rebuild. Although email and the web have greatly diminished the need for physical mail in many situations, it’s important to remember that there are many real-world scenarios where a tangible, physical object must be […]
Need a really long-life battery or heat? Try a radioisotope thermal source – problem solved! – Part 5
Power-generation and heating units using radioactive decay as their primary energy source have been successfully used in space and on Earth for over 60 years. RHU principles and technology are similar in many ways to those of the RTG, but with important differences in objective and implementation. Q: We’ve looked at the use of radioactive […]
Need a really long-life battery or heat? Try a radioisotope thermal source – problem solved! – Part 4
Power-generation and heating units using radioactive decay as their primary energy source have been successfully used in space and on Earth for over 60 years. Q: How much power does a single Pu-238 RTG core generate? A: The newest thermoelectric converters using PbTe/TAGS-based thermocouples can produce between 100 and 125 Watts of electrical energy from […]
Need a really long-life battery or heat? Try a radioisotope thermal source – problem solved! – Part 3
Power-generation and heating units using radioactive decay as their primary energy source have been successfully used in space and on Earth for over 60 years. This part looks at RTG operation in detail. Q: What’s this about radioactive decay and heat? A: Heat is generated when the natural or man-made unstable isotopes of elements undergo […]
Need a really long-life battery or heat? Try a radioisotope thermal source – problem solved! – Part 2
Power-generation and heating units using radioactive decay as their primary energy source have been successfully used in space and on Earth for over 60 years. This part looks at the principles and implementation of radioisotope-based heat and power. Q: What has been the solution to this challenge? A: It’s the elegant merging of two basic […]
Need a really long-life battery or heat? Try a radioisotope thermal source – problem solved! – Part 1
Power-generation and heating units using radioactive decay as their primary energy source have been successfully used in space and on Earth for over 60 years. Selecting a non-rechargeable (primary) battery to match the application is one of the many issues designers must contend with for the many situations in which recharging is neither feasible nor […]
