Improved Microwave Hyperthermia Device

Category – Lifesciences, Medical devices

Applications – Hyperthermia devices, Radiation therapy, Clinical thermal therapy, Cancer Treatment

Industry – Thermal Therapy Devices

Market – The global hyperthermia devices market is expected to reach USD 621 million by 2028, with a CAGR of 5.4% during 2023-2030.

A conventional hyperthermia device generally employs an applicator which enables heat transfer to the target tissue. The commonly used heating mechanisms are acoustic and electromagnetic (EM) techniques.
Fig. 1 illustrates an exemplary prior art hyperthermia device using an applicator (microwave antenna) coupled to the tissue through a surface cooling temperature controlled water bolus.
Clinically available hyperthermia antennas at 434 MHz are bulky with fixed effective heating areas. Hence, their ability to treat varying size tissue is limited.
Irrespective of the applicator used for hyperthermia devices, heat is delivered to the target tissue through a coupling medium often referred as the bolus. However, to maintain uniform volume during treatment, the circulating temperature controlled fluid (typically 37°C – 42°C) inside the bolus is required.
Based on the foregoing, there is a need exists for an improved hyperthermia device which is compact and provides a better solution.

An improved microwave hyperthermia device with compact heating applicator and inline degassing for bolus circulation.
A family of 434 MHz patch antenna (3x3x1 cm till 10X10X2cm) with varying effective heating area for treating tissue disease of varying extent.
The bolus water circulation (Fig. 4) proposed for the 434 MHz patch antennas is a smart closed loop system capable of removing dissolved micro air bubbles real time during hyperthermia treatment.
The patch antenna comprises of a radiating patch mounted on a low loss dielectric substrate which is housed inside a metal cavity and has a low loss superstrate on the patient contacting side (Fig 2 & 3).
Temperature and flow sensors embedded in the fluid flow path can measure the temperature and flow of fluids which can be further sampled and fed to the control unit/computer for process control.
A closed loop application running on the control unit/computer sends the control signals to the pump and water heater to circulate degassed temperature controlled water at a constant flow rate.

Improved microwave hyperthermia device with compact heating applicator model when compared to dielectric loaded waveguide and horn antennas at 434 MHz (10x10x10 cm).
Miniaturized microwave antennas for power transmission to the tumor/target tissue for uniform volume heating.
The different sized patch applicator with varying effective heating area accommodates varying extent tissue diseases.
Eliminates the issues with power coupling and motion artifacts during thermal therapy using MR thermometry for volumetric dose calculation by using D20 as a coupling medium.

Advantages

Can be used with MR compatible thermal therapy devices.
Single microwave source and power sensor to monitor and control power delivered during treatment.
Smaller applicator and lower system cost for heating antenna.
No need for disposable gas permeable degasser.
Since it is completely closed loop and automated, system running cost is lower.

Prof. Kavitha Arunachalam

Department of Engineering Design

TRL 3

Proof of concept (PoC) stage

Technology Transfer