Low-Cost, Handheld Tactile Imaging Device for Breast Cancer Screening

几个世纪以来，触诊一直是医生诊断疾病的常规方法。在临床乳房 检查(CBE)，医务人员筛查可疑病变(比 周围组织)用两个或三个手指触诊，然后以大约1-2英寸的固定接触进动 区域。避免不适和感觉更深的可触摸物体的典型压力范围为40-90 kPa. 然而，触诊是高度定性和主观性的；而且不可能在 形态变化。概念验证研究的目标是开发一种符合人体工程学的低成本(低于 5美元)类似听诊器的探头，可在触诊时捕捉触觉图像。探头将在30-90 kpa的压力下按压 压力和一系列图像将通过旋转探头在固定接触区域上进行实时记录 在类似于CBE的进动运动中约为1-2in2。这些研究将在一个具有良好特征的 物理模型，人造乳房，以及人体临床试验。触觉图像的分辨率将为 ~100µm，在距表面20-30 mm深度处对≥5 mm特征进行成像，相对硬度为≥的10倍 与周围的母体相比。开发这项技术的两个关键驱动因素是：(I)将CBE数字化 为40岁以下的女性和低收入人群提供两年一次的乳房X光检查之间的筛查记录 获得乳房X光检查的机会有限的国家；和(2)目前的数字CBE仪器(带 1 mm大小的传感器阵列(与建议的100μm大小像素相比)需要在皮肤上摩擦设备 以恒定的压力和速度通过将帧缝合在一起来创建图像，可能会导致 由于可触摸特征的动态变化而导致的扭曲/涂抹。建议的图像的灰度 设备将是线性的，使分析定量化，以检测局部硬度和评分并跟踪触诊 随着时间的推移。该设备的低功耗将允许连接到USB端口，以在 笔记本电脑或智能手机。成像更复杂的身体形态，如腋窝和颈部 对于淋巴结，该设计将允许不同大小的可互换设备头。在这个问题的核心 所提出的装置是一种~100 nm厚的纳米结构薄膜，它将压力转换为电信号，从而形成 触觉形象。该膜是由~5 nm厚的Au纳米颗粒组成的单层层状结构 聚合物层。当按压薄膜时，粒子之间的电子隧道电流调制为 测量局部压力。有两个具体的目标：(I)开发一种未包装的设备来证明 在分辨率、灵敏度、USB连接的电源要求和10倍图像处理能力方面的原理 使用物理模型在3-30毫米深的3-10毫米大小的较硬结构；以及(Ii)开发一种手持设备 人工乳房模型测试装置及对~50例不明原因乳房患者的有限临床研究 疼痛主诉或预定进行乳房X光检查的人。初步和公布的结果(按PI)表明 指定的分辨率、灵敏度和性能都是可能的。一项美国专利于2010年颁发。

Palpation has been routinely used by physicians to diagnose diseases for centuries. In Clinical Breast Examination (CBE), medical personnel screen for suspect lesions (that are 10- to 20-fold stiffer than surrounding tissue) by palpation using two or three fingers followed by precession about a fixed 1-2 in2 contact area. Typical pressure to avoid discomfort and also feel deeper palpable objects ranges from 40-90 KPa. However, palpation is highly qualitative and subjective; and it is not possible to follow progression in the morphological changes. The goal of the proof-of-concept study is to develop an ergonomic, low cost (less than $5) stethoscope-like probe to capture tactile images during palpation. The probe will be pressed at 30-90 KPa pressure and a series of images will be recorded in real time by pivoting the probe over a fixed contact area of about 1-2 in2 in a precession motion similar to CBE. The studies will be performed over a well-characterized physical model, an artificial breast, and a clinical test on humans. The tactile image would be at a resolution of ~100 µm to image ≥5 mm features at 20-30 mm depth from the surface with relative hardness of ≥10-fold compared to the surrounding matrix. Two key drivers for developing the technology are: (i) digitizing CBE will offer a screening record between biannual mammogram exams, for women below 40, and in low-income countries where accessibility to a mammogram is limited; and (ii) the current digital CBE instruments (with array of 1 mm size sensors compared to proposed 100 μm size pixels) require rubbing the device on the skin at constant pressure and speed to create an image by stitching together the frames, potentially causing distortions/smearing due to dynamics of the palpable features. The grayscale of the image for the proposed device will be linear making the analysis quantitative to detect local hardness and score and track the palpation over time. The low power of the device will allow connectivity to a USB port for power, signal, and imaging on a laptop computer or smart phone. To image more complex body topography, such as axillary and cervical lymph nodes, the design will allow for interchangeable device heads of different sizes. At the heart of the proposed device is a ~100 nm thick nanostructured film that converts pressure to electrical signal to form the tactile image. The film is a stratified structure of a monolayer of Au nanoparticles interposed by ~5 nm thick polymer layers. On pressing the film, the electron tunneling current between the particles modulates to measure the local pressure. There are two specific aims: (i) develop an unpackaged device to prove the principle in terms of resolution, sensitivity, power requirement for USB connectivity, and ability to image 10-fold harder structures 3-10 mm in size at depths of 3-30 mm using a physical model; and (ii) develop a handheld device for testing on artificial breast model and limited clinical study with ~50 de-identified patients with breast- pain complaints or who are scheduled for mammograms. The preliminary and published results (by PI) indicate that the specified resolution, sensitivity, and performance are possible. A US Patent was issued in 2010.