Chen Yi, Hunter Ian W
BioInstrumentation Laboratory, Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:6010-3. doi: 10.1109/IEMBS.2009.5334028.
This paper describes an indentometer device used to identify the linear dynamic and nonlinear properties of skin and underlying tissue using an in vivo test. The device uses a Lorentz force actuator to apply a dynamic force to the skin and measures the resulting displacement. It was found that the skin could be modeled as a Wiener system (i.e. a linear dynamic system followed by a static nonlinearity). Using a stochastic nonlinear system identification technique, the method presented in this paper was able to identify the dynamic linear and static nonlinear mechanical parameters of the indentometer-skin system within 2 to 4 seconds. The shape of the nonlinearity was found to vary depending on the area of the skin that was tested. We show that the device can repeatably distinguish between different areas of human tissue for multiple test subjects.
本文描述了一种压痕仪设备，该设备用于通过体内测试来识别皮肤及皮下组织的线性动力学特性和非线性特性。该设备使用洛伦兹力致动器向皮肤施加动态力，并测量由此产生的位移。研究发现，皮肤可以被建模为一个维纳系统（即一个线性动力学系统后接一个静态非线性环节）。利用随机非线性系统识别技术，本文提出的方法能够在2至4秒内识别出压痕仪-皮肤系统的动态线性和静态非线性力学参数。结果发现，非线性的形状会因测试的皮肤区域不同而有所变化。我们证明，该设备能够针对多个测试对象，对人体组织的不同区域进行重复性区分。
