基于红外热像LBP的面瘫客观评估方法

Objective Assessment of Facial Paralysis Using Local Binary Pattern in Infrared Thermography

面瘫是一种多发的面神经疾病,表现为面部一侧横纹肌运动失调。目前,尚缺乏一种客观量化的诊断和评估方法。正常人体面部的温度分布双侧对称,面瘫通常会使这种温度分布的对称性发生改变。因此,本文提出利用面部温度分布的不对称度来客观评估面瘫的严重度,利用面部红外热像图健患双侧的局部二值模式(LBP)的直方图距离来表示面部温度分布的不对称度。对面瘫患者和健康人群作对照试验,结果表明:此方法的敏感性和特异性平均为0.86和0.89,不对称度与面瘫的严重度评分正相关,平均为0.657。因此,红外热像的双侧LBP直方图距离是一项有效的用于面瘫的诊断和评估的临床指标。

Facial paralysis is a frequently-occurring disease, which causes the loss of the voluntary muscles on one side of the face due to the damages the facial nerve and results in an inability to close the eye and leads to dropping of the angle of the mouth. There have been few objective methods to quantitatively diagnose it and assess this disease for clinically treating the patients so far. The skin temperature distribution of a healthy human body exhibits a con- tralateral symmetry. Facial paralysis usually causes an alteration of the temperature distribution of body with the dis- ease. This paper presents the use of the histogram distance of bilateral local binary pattern （LBP） in the facial infra- red thermography to measure the asymmetry degree of facial temperature distribution for objective assessing the se- verity of facial paralysis. Using this new method, we performed a controlled trial to assess the facial nerve function of the healthy subjects and the patients with Bell＇s palsy respectively. The results showed that the mean sensitivity and specificity of this method are 0.86 and 0.89 respectively. The correlation eodficient between the asymmetry de- gree of facial temperature distribution and the severity of facial paralysis is an average of 0. 657. Therefore, the his- togram distance of local binary pattern in the facial infrared thermography is an efficient clinical indicator with respect to the diagnosis and assessment of facial paralysis.