Wearable ultrasound technology for real-time muscle monitoring ushers in a new era of possibilities in healthcare and human-machine interaction.

Scientists under the leadership of Professor Sheng Xu, a renowned expert in chemical engineering at the University of California, San Diego, published their groundbreaking research findings last October. 31 in . The research was a joint endeavour with Dr. Jinghong Li, a renowned pulmonologist, intensive care specialist, and professor of medicine at the University of California, San Diego’s Health Sciences.

In pneumology, a wearable device was designed to monitor diaphragmatic movement and thickness via the rib cage, providing valuable insights into respiratory health assessment. “According to Joseph Wang, a renowned professor in the Aiiso Yufeng Li Family Department of Chemical and Nano Engineering and co-author of the study, monitoring diaphragm exercise may potentially benefit individuals with respiratory conditions and those relying on mechanical ventilation.”

Researchers leveraged the forearm-mounted device to effectively capture hand and wrist movements, thereby enabling it to serve as a human-machine interface controlling a robotic arm and engaging in a digital game.

Wearable ultrasound technology could offer a groundbreaking alternative to traditional medical standards, electromyography (EMG), which typically involves applying metal electrodes to the skin to record electric muscle activity. Despite its well-established history, Electromyography (EMG) is plagued by limited predictive power and inadequate outcome measures. However, due to the complexity of signals combining from numerous muscle fibers, it can be challenging to accurately determine the specific contribution of individual fibers.

Despite its limitations, ultrasound nonetheless excels at delivering high-resolution images through deep tissue penetration, offering nuanced views of muscle function and performance. The ultrasound technology honed by Xu’s team and its partners boasts added advantages in being portable, wireless, and energy-efficient. Xiangjun Chen, a Ph.D. candidate in UC San Diego’s Materials Science and Engineering program, observed that this expertise could be seamlessly integrated into daily routines for long-term monitoring.

The gadget features a versatile silicone elastomer casing, comprising three key components: a single transducer responsible for transmitting and receiving ultrasound waves, a custom-designed Wi-Fi circuit controlling data transmission to a PC; and a lithium-polymer battery capable of powering the system for at least three hours.

This breakthrough feature lies in its ability to employ a solitary ultrasound transducer to accurately detect deep tissue structures. The transducer sends out intensity-managed ultrasound waves and records radiofrequency signals carrying rich information, facilitating medical applications such as measuring diaphragmatic thickness. By leveraging these indicators, the device can achieve exceptional spatial resolution, thereby enabling the precise identification of specific muscle movements. Using the extracted indicators, researchers created an artificial intelligence algorithm that linked them to specific muscle patterns, allowing for the precise identification of distinct hand movements with high accuracy and dependability.

By attaching this device to the rib cage, precise measurements of diaphragm thickness are possible with an accuracy of near one millimeter. The diaphragmatic thickness measurement is a clinical parameter employed to assess diaphragmatic dysfunction and forecast outcomes in patients receiving mechanical ventilation. By examining muscle activity, scientists might also identify various breathing patterns, such as subtle and profound respirations. This performance may help diagnose circumstances associated with respiratory irregularities, such as bronchial asthma, pneumonia, and chronic obstructive pulmonary disease (COPD). Researchers conducted a small-scale trial to assess the efficacy of the device in distinguishing between the respiratory patterns of individuals with chronic obstructive pulmonary disease (COPD) and those of healthy participants.

“According to Muyang Lin, a postdoctoral researcher at the University of California San Diego’s Department of Chemical and Nano Engineering, this research has significant potential for medical applications in respiratory care.”

While worn on the forearm, this device provides precise tracking of finger and wrist movements. Thanks to the cutting-edge unreal intelligence algorithm crafted by the crew, the system has the capability of identifying a multitude of hand gestures exclusively through ultrasound signals. The innovative system is engineered to recognize and safeguard 13 distinct levels of freedom, meticulously shielding 10 critical finger joints and three precise rotation angles of the wrist. As a result, it could potentially respond to even minimal wrist and finger movements with heightened sensitivity.

During proof-of-concept tests, participants utilized the wearable device on their forearm to control a robotic arm that successfully dispensed water into beakers using pipettes.

During another demonstration, users employed the device to control a digital bird’s flight through obstacles using wrist movements, showcasing its capabilities in playing a digital recreation. According to Wentong Yue, co-first author of the research and Ph.D., these demonstrations highlight the vast potential of the expertise in areas such as prosthetics, gaming, and various human-machine interfaces. A Ph.D. candidate within the Aerosol and Interface Sciences Group of the Department of Mechanical and Aerospace Engineering at the University of California, San Diego.

Transferring forward, researchers intend to significantly boost the expertise’s precision, mobility, efficacy, and computational prowess.