Engineers at Stanford University, Georgia Tech, USC Viterbi School of Engineering, and the University of Tokyo have developed a new digital oncology wearable with a sensor that can be attached to the skin to measure the changing size of tumors. Offering hope for advancements in cancer research and treatment, the Flexible Autonomous Sensor measuring Tumors, or FAST device, will continuously transmit results to a smartphone app wirelessly in real-time. The FAST device is sensitive, non-invasive, and battery-operated to one-hundredth of a millimeter (10 micrometers). The FAST device is discreet, non-invasive, and battery-operated to one-hundredth of a millimeter (10 micrometers). The FAST device is sensitive, non-invasive, and battery-operated to one-hundredth of a millimeter (10 micrometers). Researchers developed the FAST wearable to track the size of a tumor, a vital factor in determining the effectiveness of cancer drugs.
Digital Oncology Wearable – FAST
For a high-level understanding of the FAST digital oncology wearable, researchers have described the device as a fast, inexpensive, hands-free device and an accurate way to test the efficacy of cancer drugs. For a more complex description, the electronically sensitive, skin-like membrane can measure changes in tumor size to the hundredth of a millimeter. It represents a new, faster, and more accurate approach to screening cancer drugs. Ultimately, this new digital oncology wearable could lead to promising new directions in cancer treatment on a larger scale.
According to one research publication, assessing the efficacy of cancer therapeutics in mouse models is a critical step in treatment development. However, low-resolution measurement tools and small sample sizes make determining drug efficacy a complex and time-intensive task. Flexible body-worn sensors are the best choice for monitoring health or conducting studies for wearable device developers. Researchers believe the new FAST digital oncology wearable has the potential to replace the traditional method of tracking tumors via caliper and bioluminescence, allowing care providers to understand a drug’s effectiveness in days instead of weeks.
Researchers say the use of the FAST digital oncology wearable has three advantages over traditional care:
- It provides continuous, real-time monitoring.
- The sensor attached to the patch is sensitive to one-hundredth of a millimeter, enabling researchers to track minuscule changes to a tumor that other methods might not detect.
- The device is non-invasive, attaching to the skin like a bandage, and reusable.
FAST Wearable In-Depth

The design of the device is quite simple. This sensor achieves three main advances over other standard tumor measurement tools (Digital Oncology), such as calipers, implantable pressure sensors, and imagers. The sensors are composed of a flexible and stretchable skin-like polymer that includes an embedded layer of gold circuitry. This sensor is connected to a small electronic backpack, measuring the strain on the membrane—how much it stretches or shrinks—and transmits that data to a smartphone. The FAST digital oncology wearable allows potential therapies linked to tumor size regression to quickly and confidently be excluded as ineffective or fast-tracked for further study.
The creativity is in FAST’s flexible electronic material. Coated on top of the skin-like polymer is a layer of gold, which, when stretched, develops small cracks that change the material’s electrical conductivity. Stretch the material, and the number of cracks increases, causing the electronic resistance in the sensor to increase as well. The cracks come back into contact when the material contracts and conductivity improves.
One hurdle the researchers had to overcome was the concern that the sensor itself might compromise measurements by applying undue pressure to the tumor, effectively squeezing it. To circumvent that risk, they carefully matched the flexible material’s mechanical properties to the skin to make the sensor as pliant and supple as natural skin.
This work is a prime example of how wearable electronics can further precision health technologies — we can monitor the growth of a tumor with tens of micron resolution using just a sensor and a cell phone app. We can observe the progression 24/7, unlike any of the existing imaging techniques, and precisely tell if a drug is working on not in treating the tumor.
Yasser Khan, Assistant Professor of Electrical and Computer Engineering in the Ming Hsieh Department of Electrical and Computer Engineering at USC
Wearables & AI in Healthcare
The adoption of digital health technologies has significantly improved patient access to care, reduced unnecessary visits and costs, and personalized medicine. Patients (consumers) can also use digital health to manage their health better. Health care is now at a point where the intersection of user-friendly technology and medical knowledge can create meaningful improvements in quality and equity of care.
Interest in the use of wearables in medical care is increasing. The data generated by wearables can provide incredible value to healthcare services ide insights into an individual’s well-being. A crucial point for using wearables in oncology is if patients already under the burden of severe disease and oncological treatment can accept and adhere to the device. At the time of this article, there are no clear recommendations for wearables in oncology.
To learn about the four types of sensors, reference this Thryve.health article for an excellent overview.
In short, there are four main types of wearable sensors: chemical, electromechanical, optical, and electrical.
Healthcare challenges are deeply rooted in data problems. With much of health and health care moving onto digital platforms, there has been remarkable growth in the amount of information generated. AI enables greater accessibility, relevancy, and actionability of healthcare information. AI provides a way to discern meaning from large-scale real-world data. AI has the potential to predict that certain data points from wearables or smart sensors are associated with patient outcomes, such as hospitalization and worsening quality of life. As research in AI and other digital health tools continues, documentation of real-world outcomes, measured economically and clinically, is necessary.
As digital technologies such as wearables are used more frequently in evaluating new medical products and helping treat certain patient populations such as oncology patients, the field has focused extensively on regulatory acceptance in support of drug approval. In March 2022, the FDA issued draft guidance guiding digital health data acquisition in clinical investigations, furthering the widespread speculation that regulatory acceptance is not far ahead.
Despite the ever-increasing technologies and infrastructure associated with health care technologies, Digital Oncology as a subset of Digital Health is still in its infancy. Opportunities exist for a more concentrated focus on current or developing precision medicine strategies. Out-of-clinic monitoring is an area ripe for wearables to impact oncology patient outcomes. A coordinated effort is needed to build a viable path toward integrating and adopting wearables, such as digital oncology wearables, into routine clinical care.