The promise of therapeutic ultrasound

In October 2023, the U.S.-based GE HealthCare announced it will develop an ultrasound product to treat type 2 diabetes and obesity without drugs or invasive surgery. The tech shows promise to regulate the body's metabolic function by using focused ultrasound waves to stimulate the nervous system.

In the same month, the world's first regulatory approval of histotripsy, an ultrasound procedure to non-invasively liquify liver tumours, was approved in the U.S.

The ultrasound has come a long way. In the past 15 years or so, doctors have used sharply focused ultrasound waves to relieve severe pain in bone metastases, and to destroy uterine fibroids and cancerous prostate tumours. More recently, doctors have begun using ultrasound waves to selectively kill off brain cells to treat tremors such as those seen in Parkinson's disease.

Developments in such non-diagnostic or 'therapeutic' ultrasound are "probably the most exciting thing (to happen) in the field," says Himanshu Shekhar, Assistant Professor, Electrical Engineering, Indian Institute of Technology (IIT) Gandhinagar, and co-lead of the institute's Medical Ultrasound Engineering (MUSE) Lab. While ultrasound diagnostics too have advanced, "as of now, therapeutic ultrasound is probably driving the field more," he adds. In March 2024, IIT Gandhinagar will host the IEEE South Asian Ultrasonics Symposium that will bring together experts from the global ultrasound research community.

The global research pipeline suggests that the ultrasound can potentially replace or complement drugs and invasive surgery to treat diseases such as bacterial infections, depression, diabetes, obesity and a range of cancers. It has been shown to reversibly open the blood-brain barrier, potentially allowing more effective drug delivery. Most of the 166 clinical applications are at an early stage of development, according to the 2023 State of the Field Report (bit.ly/ultra-state) by the U.S.-based Focused Ultrasound Foundation (FUF).