Non-invasive, portable, affordable and safe to use technology

Indian Institute of Technology (IIT) Madras researchers have developed an ultrasound-based temperature tracking device for treatment monitoring. Unlike other imaging modalities, ultrasound combines several advantages such as safety (non-ionising), real-time capability and portability, among others.

The research team was awarded the SITARE - Gandhian Young Technological Innovation (GYTI) Appreciation 2020 for this project.

The solution involves obtaining diagnostic ultrasound signals from the tissue by applying non-invasive heat either through microwave applicator or high-intensity focused ultrasound (HIFU) and processing the signals with prior knowledge from physics of wave interaction with the tissue medium.

Thermal Therapy using HIFU is already in use for treating solid tumours (both cancerous and benign). The current state-of-the-art technology monitors treatment using MRI (MR-guided HIFU). A popular clinical case is for treating uterine fibroids.

The ultrasound-based technology will be accessible and affordable.

The practical benefits include:

* Non-invasive treatment and real-time monitoring of the process
* Safe to use as no to ionising radiation is involved
* Portable and suitable for point-of-care applications
* Ultrasound-based real-time feedback can be readily integrated with low-intensity ultrasound heat therapy devices that are commonly used in most physiotherapy centres
Hyperthermia, likewise, has shown promise for several ailments. Examples include using RF-electrode in liver disease treatment or disease of prostate.

The IIT Madras team's contribution involves monitoring this in real-time when microwave is used. This combination makes it completely non-invasive and affordable. The results from these studies have been presented and published in various international IEEE society conferences over the last year.

Highlighting the advantages of this technology, Arun K. Thittai, department of applied mechanics, IIT Madras, said, "Having multi-parametric image feedback allows for accurate real-time monitoring for a wide range of thermal therapies. These techniques can be incorporated as a software in existing scanners by the manufacturers and thus does not require any special electronics hardware."

IIT Madras are now working to design an integrated microwave applicator-cum-ultrasound-based real-time imaging feedback for a possible clinical application.

The research team involves faculty from the department of engineering design at IIT Madras for the microwave applicator aspect. A complete in-house set-up for HIFU has been established by researchers from department of applied mechanics.

Thermal (heat) therapy is used routinely for pain relief and rehabilitation of target tissue by inducing mild temperature elevation (60A°C in ablation) is also exploited as a treatment option for some diseases, including ablation of cancerous tumour. However, one of the major challenges that prevents these approaches from widespread use in clinical practice is the lack of reliable and affordable real-time feedback in the form of heat maps from the targeted treatment region.

Although several ultrasound-based methods have been proposed in literature for temperature tracking, mostly for HIFU-ablation, maps of changes in other properties at different temperature realm have not been exploited. IIT Madras researchers have the advantage of having access to complete signal chain of raw ultrasound data, and not just the final ultrasound image, that allows us to develop methods for tracking multiple different tissue parameter maps.

Collaborators, partner institutes and funding agencies of this project:

# Kavitha Arunachalam, associate professor, engineering design, IIT Madras
# Aliarshad Kothawala, PhD scholar, applied mechanics, IIT Madras (recently joined Philips India after graduation)
# Divya Baskaran, PhD scholar, engineering design, IIT Madras
The HIFU-Facility was established partly with funds from DST under FIST programme.

This research has been undertaken at the biomedical ultrasound laboratory at IIT Madras. Established in 2014, it is focussed on developing advanced, yet affordable, ultrasound imaging systems. They have filed for more than half a dozen technology patents in ultrasound imaging methods and devices in the last three years.

A start-up has also been floated to develop ultrasound scanner with proprietary technology that offers advanced and state-of-the art features, yet is affordable.