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。临床乳腺 检查（CBE），医务人员筛选可疑病变（比常规检查硬10至20倍）， 周围组织），然后在固定的1-2英寸2接触点附近进行旋进 区避免不适和感觉更深的可触知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的;并且不可能在 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、低成本的（低于 5美元）的听诊器样探头，以捕捉触摸过程中的触觉图像。探头将在30-90 KPa下受压 压力和一系列图像将被真实的记录，通过在固定的接触区域上旋转探头， 大约1-2英寸2的进动运动类似于CBE。这些研究将在一个充分表征的 物理模型、人造乳房和人体临床试验。触觉图像的分辨率为 ~100 µm，在距离表面20-30 mm深度处对≥5 mm的特征进行成像，相对硬度≥10倍 与周围的基质相比。开发该技术的两个关键驱动因素是：（i）数字化CBE将 为40岁以下和低收入妇女提供一年两次乳房X光检查之间的筛查记录 乳房X光检查的可及性有限的国家;以及（ii）目前的数字CBE仪器（ 与建议的100 μm尺寸像素相比，1 mm尺寸传感器阵列）需要在皮肤上摩擦装置 以恒定的压力和速度通过将帧拼接在一起来创建图像， 由于明显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，使得分析定量，以检测局部硬度并评分和跟踪触诊 随着时间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。对更复杂的身体地形进行成像，如腋窝和颈部 淋巴结，该设计将允许不同尺寸的可互换器械头。的核心 所提出的装置是一种~100 nm厚的纳米结构膜，其将压力转换为电信号以形成 触觉图像该薄膜是单层Au纳米粒子的层状结构，约5 nm厚 聚合物层。在按压薄膜时，粒子之间的电子隧穿电流调制为 测量局部压力。有两个具体目标：（一）开发一种未包装的设备，以证明 在分辨率、灵敏度、USB连接的功率要求以及10倍成像能力方面， 使用物理模型，在3-30 mm的深度处，尺寸为3-10 mm的较硬结构;以及（ii）开发手持式 用于在人工乳房模型上进行测试的器械，以及对约50名去识别乳腺癌患者进行的有限临床研究， 疼痛投诉或计划进行乳房X光检查的患者。初步和发表的结果（PI）表明 指定的分辨率、灵敏度和性能是可能的。2010年获得美国专利。

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.