探討諧波訊號分析磁性粒子對升溫產熱之相依性研究
Abstract
磁性奈米粒子（Magnetic Nanoparticles, MNPs）因其具備獨特的磁性行為與生物相容性，在癌症熱治療中有著重要的應用潛力，本研究結合 Labview 程式端、激發線圈與接收線圈，建構出具備溫度監控與磁場控制功能的自動控制系統，利用磁性奈米粒子於不同溫度下產生的諧波訊號，作為推估溫度的依據，實驗透過調變磁場強度（75 Oe及125 Oe）以及溫度，量測磁性奈米粒子在交流磁場下的訊號，建立其與溫度之間的對應關係。在本研究中，除了從磁性奈米粒子的磁化響應中提取溫度相關資訊（5th/3rd 諧波比值）外，亦結合程式端控制技術，實現對磁場強度的即時自動調整，進而達到溫度的自動控制，此方式依據磁性奈米粒子所回應的諧波比值變化，反映磁性奈米粒子所在環境的溫度變化，再將該比值對應至事先建立的比值與溫度關係公式，藉此推估實際溫度，系統再透過Labview程式進行控制，根據該溫度與設定目標溫度間的誤差，自動調整輸入電壓以改變線圈中的電流，從而改變外加磁場的強度，使磁性奈米粒子達到設定之目標溫度。
Magnetic nanoparticles (MNPs), owing to their unique magnetic behavior and biocompatibility, have shown great potential for applications in cancer hyperthermia therapy. In this study, a fully automated control system with integrated temperature monitoring and magnetic field regulation was developed using LabVIEW programming, an excitation coil, and a receiving coil. The system utilizes the harmonic signals generated by MNPs at different temperatures as a basis for temperature estimation. By varying the magnetic field strength (75 Oe and 125 Oe) and the temperature, the response signals of the MNPs under an alternating magnetic field were measured, allowing the establishment of a correlation between the harmonic characteristics and temperature.In addition to extracting temperature-related information—specifically, the 5th/3rd harmonic ratio—from the magnetization response of the MNPs, this study also incorporates programmatic control techniques to achieve real-time automatic adjustment of the magnetic field strength, thereby enabling automated temperature control. Changes in the harmonic ratio reflect variations in the ambient temperature of the MNPs. This ratio is then mapped to a pre-established calibration function relating harmonic ratio and temperature to estimate the actual temperature. The system, via the LabVIEW interface, adjusts the input voltage according to the error between the estimated temperature and the target temperature. This voltage modulation changes the current in the excitation coil, thereby regulating the applied magnetic field strength to bring the MNPs to the desired temperature.
Magnetic nanoparticles (MNPs), owing to their unique magnetic behavior and biocompatibility, have shown great potential for applications in cancer hyperthermia therapy. In this study, a fully automated control system with integrated temperature monitoring and magnetic field regulation was developed using LabVIEW programming, an excitation coil, and a receiving coil. The system utilizes the harmonic signals generated by MNPs at different temperatures as a basis for temperature estimation. By varying the magnetic field strength (75 Oe and 125 Oe) and the temperature, the response signals of the MNPs under an alternating magnetic field were measured, allowing the establishment of a correlation between the harmonic characteristics and temperature.In addition to extracting temperature-related information—specifically, the 5th/3rd harmonic ratio—from the magnetization response of the MNPs, this study also incorporates programmatic control techniques to achieve real-time automatic adjustment of the magnetic field strength, thereby enabling automated temperature control. Changes in the harmonic ratio reflect variations in the ambient temperature of the MNPs. This ratio is then mapped to a pre-established calibration function relating harmonic ratio and temperature to estimate the actual temperature. The system, via the LabVIEW interface, adjusts the input voltage according to the error between the estimated temperature and the target temperature. This voltage modulation changes the current in the excitation coil, thereby regulating the applied magnetic field strength to bring the MNPs to the desired temperature.
Description
Keywords
磁性奈米粒子, 磁粒子熱治療, 溫度監控, Magnetic nanoparticles, magnetic hyperthermia, Temperature monitoring