Affordable and super-portable: what’s next in medical ultrasound

Medical ultrasound technology has come a long way since the first Somascope. Fashioned from a horse trough and converted radar frame, the instrument fascinated readers of Life magazine in 1954. Its developers – a physician, a radiologist and two electrical engineers at the Denver Veterans Affairs Hospital – had obtained 2-D images of a kidney by submerging one of the engineers in a water bath and sending sound waves echoing through his body with a clunky transducer.

Today, of course, ultrasound is an invaluable medical tool. Harmless and noninvasive, its use of sound waves to visualize biological structures that X-rays can’t detect has a wide variety of applications, including cancer, gynecology, cardiology, physical therapy and vascular medicine. In the six decades since the debut of the Somascope, sonography has drastically improved through both advances in electronics and piezoelectric materials and the integration of Doppler ultrasound, with increasingly sophisticated imaging technology and exponentially faster processing power.

Still, modern ultrasound isn’t perfect. It’s expensive and places large demands on power supplies. Instruments generate interfering noise and produce vast amounts of data that result in less-than-precise images. That’s why our company continues to help make innovative improvements to the technology.

Ultrasound for everyone

Designers can shape the next generation of medical ultrasound scanners with reference designs in the TI Designs reference design library and our integrated circuit portfolio. Recently unveiled reference designs will enable smarter ultrasound scanners that, with fewer components, will be more power-efficient. More precise imaging and an enhanced signal-to-noise ratio help generate higher-quality images and clearer data readings, while cart-based scanners benefit from more compact, low-noise power solutions.

The objective is affordable, compact ultrasound devices capable of producing real-time, high-resolution 3-D images – especially of the heart – for more accurate diagnoses and treatment plans. Some industry observers predict that ultrasound scanners could replace stethoscopes hanging around physicians’ necks – and that’s not far away.

It’s a future in which ultrasound is so widely available that underserved populations worldwide will benefit from improved medical care. That time is approaching fast, and some communities are already benefiting. For example:

  • Portable, cart-based ultrasound equipment helped 10 U.S. medical professionals in Mwanza, Tanzania perform surgeries on pediatric patients with anorectal malformations.
  • In rural Uganda, access to low-cost, robust ultrasound machines has improved prenatal care by drawing pregnant women to clinics for imaging.
  • Technology innovators in Nairobi, Kenya, have developed a wind-up portable Doppler ultrasound machine that doesn’t require any power. The machine also creates a digital readout of a fetus’ heartbeat.
  • In Nigeria, a three-year program will train some midwives and healthcare providers to use a handheld machine the size of a smartphone.
  • A Netherlands professional soccer team plans to begin using portable ultrasound, which works through a smartphone app and a handheld transducer to assess player injuries on the field.

At upwards of $100,000 for a complete immovable system and around $40,000 for a portable system – that is, any unit not permanently attached to a cart – ultrasound technology is out of reach for many populations.

But one of our company's medical systems architects – Ravindra Munvar in Bangalore, India – says that technological improvements are reducing costs. For instance, as channel count increases to improve the depth and resolution of ultrasound images, the cost per channel has dropped from more than $20 to less than $2. Such developments could push the price point of portable ultrasound as low as $5,000, he said. One vendor is even promising to bring a $2,000 smartphone plug-in probe to market in early 2018.

Power-efficient and more precise

Our company is taking several approaches to address customers’ needs for combining minimal power consumption, miniaturization and low noise with high-quality imaging.

Ravindra explained why improving the power efficiency of medical ultrasound scanners is important. “As the number of channels increases, so does the use of power,” he said. “Our customers are trying to maintain a power budget, so we have a big responsibility to improve power efficiency, especially for portable and handheld systems.” Cooling system requirements are also dependent on power efficiency, he said. Moving parts such as fans can interfere with image precision, so “innovative cooling mechanisms are needed.”

To improve power efficiency for cart-based ultrasound technology, new reference designs from our company enable designers to reduce the size of bulk capacitors, maintain optimized efficiency and minimize power-supply components while maximizing efficiencies in various ultrasound systems.

Our reference designs also cater to the makers of smaller systems. Innovative packaging enables more efficient power use, keeps devices cooler and ensures electromagnetic compatibility. A high level of integration in analog front-end and similar devices means that more electronics can fit inside a probe.

The High-Resolution, High-SNR True Raw Data Conversion Reference Design for Ultrasound CW Doppler addresses key ultrasound design challenges with the industry’s best signal-to-noise ratio, as well as the flexibility to implement digital filtering to further improve signal-to-noise ratio  and resolution. The industry’s lowest noise time-gain compensation makes more precise imaging possible.

With the advent of smart probes that can connect to any processing or display system, wireless features are key.

“Smart probes process most data internally, but if you have to reduce power dissipation, then some of the data processing might need to take place on the display system,” Ravindra said. “Many customers use TI’s WiLink™ devices to achieve this goal.”

What’s next in ultrasound?

Engineers from our company continue to contribute innovations that will enable designers to offer higher-quality ultrasound at reduced price points. To serve populations in the developing world, improvements that contribute to affordability and portability are key. And where backup systems and repair service are unavailable, robustness and reliability are crucial too. Ravindra predicts that the “digital stethoscope that can see inside your body” will become an easy-to-use commodity.

But handheld ultrasound machines won’t make larger machines obsolete. Niche and new applications such as real-time 3-D imaging and elastography will still happen on cart-based systems. And hospitals might prefer to invest in instruments that can’t easily walk away in someone’s pocket.

Soon enough, Ravindra said, the challenge will no longer be to develop smaller, more affordable ultrasound technology. Instead, it will be processing, transferring and storing the massive amounts of data that the ubiquitous instruments produce. Limitations will arise in terms of the number of radiologists and other doctors who can decipher meaningful information from this vast data. However, in the future this will also drive toward more automation in diagnosis and standardization of analysis.

The possibilities are vast, but, more importantly, the impact that our innovations can have on improving the quality of life and saving human lives is significant. See what technology TI has in store for your next ultrasound design.