The Evolution of Ultrasound Technology From A-Mode to POCUS AI

Ultrasound AI

Ultrasound technology has become integral to modern medicine, allowing physicians and healthcare professionals to see inside the human body quickly and conveniently without invasive procedures. From modest origins to today's sophistication and a future filled with potential for ultrasound AI, ultrasound's evolution into one of the world's most prevalent medical tools encompasses numerous innovations and transformative breakthroughs.

Ultrasound's Role in Healthcare in the 20th Century

The earliest recorded studies of soundwaves date back hundreds of years. However, it wasn’t until the mid-20th century that ultrasound technology revolutionized modern medicine.

1940s and 1950s

The 1940s sparked a new wave of ultrasound research and development. Researchers began experimenting with ultrasonic waves for medical diagnosis, developing “A-mode” (amplitude-mode) ultrasound in the 1940s and 1950s. Neurologist Karl Dussik is often credited with conducting some of the first experiments using ultrasound to diagnose brain tumors, employing A-mode to detect changes in ultrasound transmission through the skull. While Dussik's work laid important groundwork for developing A-mode ultrasound, other scientists and clinicians refined the technology and expanded its applications.

1950s and 1960s

As technology advanced, A-mode found applications in various fields, notably in ophthalmology and obstetrics. It was instrumental in measuring eye structures and detecting fetal heartbeats. However, the scope was limited due to its one-dimensional output, providing limited anatomical information.

Ian Donald and his colleagues in Scotland made significant advancements in the 1950s and 1960s, resulting in the first B-mode (brightness modulation) ultrasound. The images displayed different tissues as varying shades of gray based on the intensity of the reflected sound waves. Donald’s groundbreaking work led to the development of the first real-time ultrasound scanner, enabling visualization of fetal movements and heartbeat, thereby revolutionizing prenatal care.

1970s and 1980s

In subsequent decades, advancements in electronics and computing greatly enhanced B-mode ultrasound imaging. Real-time imaging became possible, dramatically increasing its diagnostic utility. Improvements in transducer design and image processing algorithms led to clearer, more detailed images.

As ultrasound technology advanced, particularly with the development of B-mode (brightness mode) and later Doppler and color Doppler modes, the use of A-mode ultrasound declined in many clinical areas. However, A-mode continued to be valuable in specific applications such as ophthalmology and neurology, where precise measurements were essential.

The integration of Doppler technology with B-mode imaging allowed the visualization of blood flow, adding functional information to anatomical details. The first portable and handheld ultrasound devices emerged during this period, expanding the technology's accessibility and applications.

Ultrasound's Role in Healthcare in the 21st Century and Beyond

Ultrasound imaging has enhanced image quality, resolution, and processing speed with digital technology. Three-dimensional (3D) ultrasound, building upon B-mode, provides volumetric representations of tissues and organs, opening new dimensions in diagnostics and procedural guidance.

Ultrasound technology's versatility extends to many applications in various medical specialties. From cardiology and radiology to urology and gastroenterology, ultrasound is now indispensable for diagnosing various conditions, ranging from tumors and cysts to vascular abnormalities, musculoskeletal injuries and more.

While ultrasound tools continue to become more accessible, technical advancements and innovations further improve image quality and resolution to enable more accurate diagnoses. Ongoing research and development will continue to push boundaries, exploring novel applications such as molecular imaging, targeted drug delivery and therapeutic ultrasound innovations. Looking forward, efforts to enhance the integration of ultrasound with other imaging modalities, such as MRIs and CT scans, will further contribute to comprehensive diagnostic insights and personalized treatment strategies.

Going Small is Huge

Despite ultrasound’s rapid evolution and groundbreaking potential, many of the early commercially available machines were large, expensive, difficult or impossible to make portable. With devices mostly confined to hospitals’ radiology, cardiology or obstetrics departments, benefits to a large population of patients were severely limited.

The miniaturization of ultrasound devices and the advent of portable ultrasound systems in the past two decades represent the industry’s most significant breakthrough in democratizing access to medical imaging. Portable point-of-care ultrasound (POCUS) devices can offer flexibility, affordability and ease of use, particularly in resource-limited settings, empowering healthcare providers to perform rapid assessments and interventions at the patient's bedside.

Laptop- and cart-based systems are easier to relocate across hospital settings and clinical offices. At the same time, handheld models are even easier and smaller and often offer significant cost savings over larger alternatives. Research And Markets project the global portable ultrasound equipment market will reach $2.5 billion by 2026 and $2.9 billion by 2030.

As hospital systems across the globe look to expand access to medical imaging at the point of care, POCUS devices have been growing in popularity as an avenue to accomplish this goal. Also, for healthcare professionals working in remote or rural settings, the portability of handheld ultrasound represents access to medical imaging in locations where previously it would be difficult or impossible to bring that option to patient care.

Wearable Tech

University of California researchers and MIT engineers are among the pioneers developing ultrasound stickers and patches. This technology represents a significant advancement in wearable, portable, user-friendly ultrasound applications. With convenient, continuous and non-invasive imaging capabilities, ultrasound patches are widely used in ambulatory settings, remote patient monitoring, and personalized in-home healthcare.


Recent innovative research illuminates the possibilities for using ultrasound to precisely activate specific neurons that can influence brain functions. The relatively small but growing field known as sonogenetics explores the intersection of neurology and ultrasonic technologies. Using ultrasound for non-invasive brain stimulation and communication carries significant implications for treating neurological disorders and enhancing neuroimaging techniques.


The emerging field of acousticeuticals involves using therapeutic ultrasound as a form of drug-free treatment and medication. Using ultrasound waves to trigger or modulate biological effects without pharmaceuticals opens new treatment pathways for various conditions, offering non-invasive and side-effect-free alternatives to traditional drug therapies.

High-Intensity Focused Ultrasound

While high-intensity focused ultrasound (HIFU) has existed for decades, research and advancements continue to expand its capabilities and potential applications while improving its efficacy and safety profile. HIFU is increasingly popular in non-invasive surgeries, particularly in oncology for tumor ablation, as well as for pain management and treating conditions, including uterine fibroids.

A New Frontier: Ultrasound AI

The ongoing integration and adoption of artificial intelligence (AI) algorithms in ultrasound represent significant, exciting possibilities in enhancing diagnostic capabilities and lowering the barrier of entry to learning ultrasound scanning.

Ultrasound AI leverages artificial intelligence's ability to draw from training on medical imaging datasets, which may consist of thousands of sonograms annotated by human experts. AI algorithms can help analyze ultrasound images, detect abnormalities, quantify tissue characteristics and assist clinicians in making more accurate diagnoses.

AI offers easier image capture, higher accuracy and more consistent scanning, allowing more caregivers to perform a higher volume of ultrasounds and deliver better outcomes. Research from a 2021 Nature study shows AI assistance helps radiologists decrease false positive rates by 37.3 percent and reduce biopsy requests by 27.8 percent while maintaining the same level of sensitivity.

While AI technology within modern medicine is in its early stages of widespread adoption, healthcare professionals recognize its vast potential. Nearly 80% of Exo’s 2023 POCUS Survey Report respondents say AI will positively impact point-of-care ultrasound. Healthcare providers and educators believe learning assistance on properly using ultrasound is one of AI’s most impactful benefits. With AI tools guiding nurses to administer central lines or helping medical students perform a lung assessment, AI can play a critical role in helping soften ultrasound’s learning curve and expanding POCUS usage worldwide.

Exo and Ultrasound AI

Ultrasound technology’s journey from nascent beginnings to contemporary sophistication and the future’s horizon is a testament to human ingenuity and relentless pursuit of excellence.

With Exo’s AI, new learners and seasoned experts can arrive at helpful answers accurately and efficiently. Learn about Exo’s AI, including our AI manifesto of how we approach testing and designing our AI to meet the needs of patients and caregivers.