Autonomous animal heating and cooling system for temperature-regulated magnetic resonance experiments

Area of Science:

• Preclinical research
• Biomedical engineering
• Magnetic resonance imaging

Background:

• Temperature significantly impacts magnetic resonance (MR) properties like T1, T2, and diffusion.
• Accurate thermoregulation is critical in preclinical animal models, especially under anesthesia, to maintain physiological stability and experimental integrity.
• Existing methods for temperature control in animal studies can be inadequate, affecting physiological parameters and MR data.

Purpose of the Study:

• To develop and validate an open-source, actively controlled heating and cooling system for precise animal temperature regulation in preclinical settings.
• To demonstrate the system's efficacy in maintaining stable animal body temperatures during MR experiments.
• To showcase the system's capability in modulating specific tissue temperatures, such as brain temperature.

Main Methods:

• Design of an open-source system utilizing Peltier modules for heating/cooling a circulating water bath.
• Implementation of active temperature feedback using a rectal thermistor and a proportional-integral-derivative (PID) controller.
• Validation in phantom, mouse, and rat models, with additional demonstration using invasive optical probes and noninvasive MR spectroscopic thermometry.

Main Results:

• The system achieved precise temperature regulation, with a standard deviation of less than 0.1°C in animal models upon convergence.
• Successful demonstration of modulating brain temperature in mice using both invasive and noninvasive techniques.
• The system proved effective in maintaining stable physiological conditions for preclinical MR studies.

Conclusions:

• The developed open-source system provides a reliable and accurate solution for animal thermoregulation in preclinical research.
• Precise temperature control is essential for reproducible and high-quality preclinical magnetic resonance data.
• This technology facilitates advanced research by enabling controlled modulation of animal body and brain temperatures.