IIT Madras develop ultrasound-based temperature tracking for treatment monitoring

Non-invasive and portable, this is safer to use as there is no exposure to ionising radiation and is suitable for point-of-care applications

The IIT Madras Research Team was reportedly awarded the ‘SITARE – Gandhian Young Technological Innovation (GYTI) Appreciation 2020’ for this project.

This solution involves obtaining diagnostic ultrasound signals from the tissue region of interest inside the body, where heating is applied non-invasively from outside either through microwave applicator or High-intensity Focused ultrasound (HIFU), and processing these signals, specifically, using 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 technology developed by IIT Madras researchers will be ultrasound-based monitoring, instead of MRI, thus making it accessible and affordable.

The release lists the practical benefits of this technology including that it is a non-invasive treatment and real-time monitoring of the process. It is also safe to use as no exposure to ionising radiation is involved. Thirdly, it is portable and suitable for point-of-care applications and fourthly, the ultrasound-based real-time feedback can be readily integrated with low-intensity ultrasound heat therapy devices that are commonly used in most physiotherapy centers

Hyperthermia, likewise, has shown promise for several ailments. Examples include using RF-electrode in liver disease treatment or disease of prostate. The IIT Madras researchers’ contribution is to monitor this in real-time when, specifically, 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 compared to existing technologies, Prof Arun 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.”

Currently, the IIT Madras researchers have demonstrated the feasibility of the methods using experiments done on tissue mimicking phantoms and ex-vivo tissue samples. They are now working to convert these proof-of-concept methods 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 ablation has been established by the researchers from Department of Applied Mechanic, IIT Madras.

Thermal (heat) therapy is used routinely for pain relief and rehabilitation of target tissue by inducing mild temperature elevation (<42°C) on them. Sufficient heating of target tissue inside the body (42°C-45°C: in hyperthermia; and >60°C in ablation) is also exploited as a treatment option for some disease, including ablation of cancerous tumour. However, one of the major challenges that prevents these approaches from wide-spread 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 a different temperature realm have not been exploited. IIT Madras Researchers have the advantage of having access to a 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.

The List of Collaborators, partner institutes and funding agencies of this project include Dr Kavitha Arunachalam, Associate Professor, Dept. of Engineering Design, IIT Madras; Aliarshad Kothawala, PhD scholar, Dept. of Applied Mechanics, IIT Madras (recently joined Philips India after graduation); and Divya Baskaran, PhD scholar, Dept. of 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 spun-off to develop ultrasound scanner with proprietary technology that offers advanced and state-of-the art features, yet is affordable.