PDF(Pubmed)
Abstract：
A calibrated palpation sensor has been developed for making instrumented Digital Rectal Examinations (iDREs) with a view to assessing patients for prostate cancer. The instrument measures the dynamic stiffness of the palpable surface of the prostate, and has been trialled on 12 patients in vivo. The patients had been diagnosed with prostate cancer and were scheduled for radical prostatectomy. As far as possible, patients with asymmetric disease were chosen so as to give a variation in gland condition over the palpable surface. The device works by applying an oscillating pressure (force) to a flexible probe whose displacement into the tissue is also measured in order to yield a dynamic stiffness, the static stiffness being incidentally measured at the mean oscillatory force. The device was deployed mounted on the index finger of a urologist and measurements taken at 12-16 positions on each patient using light and firm pressure and palpation frequencies of 1 or 5 Hz. In parallel, conventional DRE assessments were made by a consultant urologist for cancer. After in vivo measurement, the glands were removed and examined histologically with each palpation point being classified as cancerous (C) or not (NC). The work has established the first measurements of static modulus of living prostate tissue to be: 26.8 (13.3) kPa for tissue affected by prostate cancer (C classification), and 24.8 kPa (11.9) for tissue unaffected by cancer (NC classification), values quoted as median (interquartile range). The dynamic properties were characterised by: dynamic modulus, 5.15 kPa (4.86) for the C classification and 4.61 kPa (3.08) for the NC classification and the time lag between force and displacement at 5 Hz palpation frequency, 0.0175 s (0.0078) for the C classification and 0.0186 s (0.0397) for the NC classification, values again quoted as median (interquartile range). With the limited set of features that could be generated, an Artificial Neural Network (ANN) classification yielded a sensitivity of 97%, negative predictive value of 86%, positive predictive value of 67% and accuracy of 70% but with relatively poor specificity (30%). Besides extending the feature set, there are a number of changes in probe design, probing strategy and in mechanics analysis, which are expected to improve the diagnostic capabilities of the method.
摘要：
已开发出校准的触诊传感器，用于制作仪器化数字直肠检查（iDRE），以评估患者的前列腺癌。该仪器测量前列腺可触及表面的动态刚度，并在体内对12名患者进行了试验。患者已被诊断为前列腺癌，并计划进行根治性前列腺切除术。尽可能,选择患有不对称疾病的患者，以使可触知表面的腺体状况发生变化。该设备通过向柔性探针施加振荡压力（力）来工作，该探针进入组织的位移也被测量，以产生动态刚度。静态刚度是在平均振荡力下偶然测量的。将该装置安装在泌尿科医生的食指上,并使用轻的和坚固的压力和1或5Hz的触诊频率在每个患者的12-16个位置进行测量。并行,常规DRE评估由泌尿科顾问进行癌症.体内测量后，切除腺体并进行组织学检查，每个触诊点被分类为癌性（C）或非癌性（NC）。这项工作已经建立了活前列腺组织的静态模量的第一个测量值：对于受前列腺癌影响的组织（C分类）为26.8（13.3）kPa，未受癌症影响的组织（NC分类）为24.8kPa（11.9），引用的值为中位数(四分位数范围)。动态特性的特征在于：动态模量，C分类为5.15kPa（4.86），NC分类为4.61kPa（3.08），以及在5Hz触诊频率下力与位移之间的时滞，C分类为0.0175s(0.0078)，NC分类为0.0186s(0.0397)，值再次引用为中位数(四分位数范围)。使用可以生成的有限特征集，人工神经网络(ANN)分类的灵敏度为97%，阴性预测值为86%，阳性预测值为67%，准确性为70%，但特异性相对较差(30%)。除了扩展功能集之外，探头设计有许多变化，探测策略和力学分析，有望提高该方法的诊断能力。
