Design and performance evaluation of magnetic hyperthermia instrument with embedded PI control

Area of Science:

• Biomedical Engineering
• Oncology
• Materials Science

Background:

• Hyperthermia is an effective, non-invasive cancer treatment requiring precise temperature control.
• Accurate thermal dose delivery minimizes damage to healthy surrounding tissues.
• Existing hyperthermia instruments may lack affordability or indigenous design.

Purpose of the Study:

• To report the indigenous development of a custom-designed hyperthermia instrument.
• To implement an advanced RISC machine (ARM)-based embedded closed-loop proportional-integral (PI) controller for precise temperature management.
• To explore the system's potential for in vitro hyperthermia studies.

Main Methods:

• Developed a custom hyperthermia instrument featuring an ARM-based PI controller.
• Controlled the DC bias of a Mazzilli oscillator-based half-bridge inverter via the PI controller.
• Utilized an infrared (IR) radiation thermometer for real-time temperature monitoring and feedback control of alternating magnetic field (AMF) amplitude to regulate magnetic nanoparticle (MNP) temperature.

Main Results:

• Successfully conducted in vitro experiments with the custom-designed heater and controller.
• Achieved precise temperature control with a standard deviation of approximately 0.3°C and overshoot within 3°C.
• Obtained a satisfactory specific absorption rate (SAR) value, demonstrating efficient energy deposition.

Conclusions:

• The indigenously developed hyperthermia instrument and PI controller are feasible for preclinical studies.
• The system demonstrates potential for effective and precise temperature control in hyperthermia therapy.
• Customizations could enable future clinical applications.