Microwave ablation is under investigation as a minimally-invasive treatment for uterine fibroids. Computational models play a vital role in the development, evaluation and characterization of candidate ablation devices. The temperature-dependent dielectric properties of fibroid tissue are essential for accurate computational modeling. Objective: To measure the broadband temperature-dependent dielectric properties of uterine fibroids excised during hysterectomy procedures. Methods: The open-ended coaxial probe method was employed for measuring the broadband dielectric properties of freshly excised human uterine fibroid samples (n=6) obtained from an IRB-approved tissue bank. The dielectric properties (relative permittivity, ε _r, and effective electrical conductivity, σ _eff) were evaluated at temperatures ranging from 23 C–150 C, over the frequency range of 0.5–6 GHz. Linear piecewise parametrization with respect to temperature and quadratic parametrization with respect to frequency was applied to characterize broadband temperature-dependent dielectric properties of fibroid tissue. Results: The baseline room temperature values of ε _r vary from 57.55.29 to 44.55.77 units and σ _eff changes from 0.910.19 to 6.020.7 S m⁻¹ over the frequency range of 0.5–6 GHz. At temperatures close to the water vaporization point, ε _r, drops considerably i.e. to 12%–14% of its baseline value for all measured frequencies. σ _eff values initially rise till 98 C and then fall to 11%–13% of their baseline values at 125 C for frequencies≤2.45 GHz. The σ _eff follows a decreasing trend for frequencies>2.45 GHz and drops to∼6 % of their baseline room temperature values. Conclusion: The temperature dependent dielectric properties of uterine fibroid tissues over microwave frequency range are reported for the first time in this study. Parametric models of uterine fibroid dielectric properties are also presented for incorporation within computational models of microwave ablation of fibroids.

微波消融作为子宫肌瘤的微创治疗正在研究中。计算模型在候选消融装置的开发、评估和表征中起着至关重要的作用。肌瘤组织的温度依赖性介电特性对于精确的计算建模至关重要。目的：测量子宫切除术中切除的子宫肌瘤的宽带温度依赖性介电特性。方法：采用开放式同轴探针法测量从 IRB 批准的组织库获得的新鲜切除的人类子宫肌瘤样本 (n=6) 的宽带介电特性。_{介电特性（}相对介电常数，εr 和有效电导率σ _eff ) 在 23 C–150 C 的温度范围内，在 0.5–6 GHz 的频率范围内进行评估。应用相对于温度的线性分段参数化和相对于频率的二次参数化来表征纤维瘤组织的宽带温度依赖性介电特性。结果：在 0.5-6 GHz 的频率范围内， ε _r的基线室温值从 57.55.29 变化到 44.55.77 单位，σ _eff从 0.910.19 变化到 6.020.7 S m ^{-1 。}在接近水汽化点的温度下，ε _r，显着下降，即所有测量频率的基线值的 12%–14%。对于频率≤2.45 GHz， σ _eff值最初上升到 98 C，然后在 125 C 时下降到其基线值的 11%–13%。当频率>2.45 GHz 时， σ _eff呈下降趋势，并下降至其基线室温值的 6%。结论：本研究首次报道了微波频率范围内子宫肌瘤组织的温度依赖性介电特性。还提出了子宫肌瘤介电特性的参数模型，用于纳入肌瘤微波消融的计算模型中。