Beijing Key Laboratory of Pre-clinical Research and Evaluation for Cardiovascular Implant Materials, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Centre for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Center of Cardiac Surgery for Adults, State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Centre for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Cryo Letters. 2020 May-Jun;41(3):140-144.
Noninvasive monitoring of cryosurgery is important for performing precise monitoring of the freezing process in situ and evaluating postoperative effects after therapy. One potential approach is to monitor the normal and freeze-thawed tissues through ultrasonic backscattered signal processing.
A noninvasive method for cryosurgery monitoring based on the analysis of microstructural characteristics of in vitro porcine liver tissues at different state including normal and freeze-thawed tissues by estimating the center frequency of scatterers (CFS) using the autoregressive (AR) cepstrum of ultrasonic backscattered signals.
The method is based on the discrete scattering model described in the tissue characterization literature and the observation that most biological tissues are semi-regular scattering lattices. A total of ten in vitro porcine liver samples were used and freeze by water bath in the experiments.
Experimental results show that the CFS in porcine liver tissues decreases after pre-frozen and then thawed.
The CFS obtained using this method may be used as a characteristic parameter for tissue characterization in noninvasive monitoring the transition zone between frozen and unfrozen tissues during the surgical therapy, and evaluating postoperative effects.
在进行原位冷冻过程的精确监测和评估治疗后的术后效果时，对冷冻手术的非侵入性监测很重要。一种潜在的方法是通过超声背散射信号处理来监测正常组织和冻融组织。
提出一种基于对不同状态（包括正常和冻融组织）的体外猪肝组织微观结构特征的分析，通过对超声背散射信号的自回归（AR）倒谱估计散射体的中心频率（CFS），实现对冷冻手术的非侵入性监测。
该方法基于组织特征化文献中描述的离散散射模型，以及观察到的大多数生物组织是半规则散射晶格的现象。实验中使用了总共十个体外猪肝样本，并通过水浴进行冷冻。
实验结果表明，在预冷冻和解冻后，猪肝组织中的 CFS 会降低。
该方法获得的 CFS 可作为手术治疗过程中用于评估冷冻与未冷冻组织之间过渡区的特征参数，以及用于评估术后效果。
