Design, prototyping, and optimization of a handheld refrigeration probe system for dental pulp testing

Abstract

Refrigeration technology is widely used in medical applications such as dental pulp testing, therapeutic hypothermia, and cryosurgery. There is a growing trend to replace conventional cryogen-based approaches with thermoelectric cooler-based thermal management systems. This transition is driven by the notable advantages of thermoelectric (TE) coolers, which overcome the limitations of cryogens while providing a safe, flexible, reusable, stable, and environmentally friendly refrigeration temperature. Within this transition, achieving a −30 °C refrigeration temperature, which is important for pulp testing, within the confines of a handheld space remains challenging. This study successfully addressed this challenge by introducing a high-performance heat dissipation component based on the principle of conjugate heat transfer (CHT). A handheld refrigeration probe system for dental pulp testing was developed. The prototype has the salient features of achieving a −35 °C temperature with a duration time of 4 min and a response time of 30 s within a cylindrical space of ∅ 35 mm × 150 mm. Furthermore, by geometrical optimization of the TE module and topology optimization of the heat dissipation design, the lowest temperature of the proposed probe can reach −44 °C. Overall, this study demonstrates the capabilities of TE and CHT in refrigerating and highlights the potential of this combined technology to improve the dental pulp testing in a handheld, stable, and ecological manner.