Oka H, Irie T
Faculty of Engineering, Okayama University, Japan.
Med Prog Technol. 1997;21 Suppl:1-4.
The human body is a medium which consists of various tissues such as skin, fat, muscle and bone. Each of the tissues has their own biomechanical properties. We have measured biomechanical impedances by applying a random vibration (30-1000 Hz) to the layered model of human tissues to study the occurring mechanism of impedances measured at the skin surface. The data showed that the top tissue layer and the underlying layer both contribute to the impedance depending on the thickness of the top layer. The contribution of the underlying layer was clearer over the frequency range from 30 to 400 Hz. Quantitatively we found the following: The impedance measured at the surface was roughly expressed as the model which is connected in series by the impedances of the top and underlying tissues. The contribution of the underlying tissue decreased according to the increase of the thickness of the top tissue, and disappeared over a certain thickness (18 mm in this paper).
人体是一种由皮肤、脂肪、肌肉和骨骼等各种组织构成的介质。每种组织都有其自身的生物力学特性。我们通过对人体组织分层模型施加随机振动（30 - 1000赫兹）来测量生物力学阻抗，以研究在皮肤表面测得的阻抗的产生机制。数据表明，顶层组织和下层组织都对阻抗有贡献，这取决于顶层的厚度。在30至400赫兹的频率范围内，下层组织的贡献更为明显。从定量角度我们发现：在表面测得的阻抗大致可表示为由顶层和下层组织的阻抗串联而成的模型。下层组织的贡献随着顶层组织厚度的增加而减小，并在一定厚度（本文中为18毫米）时消失。
