Astrand Anders P, Jalkanen Ville, Andersson Britt M, Lindahl Olof A
Department of Applied Physics and Electronics, Umeå University, SE-901 87 Umeå, Sweden.
J Med Eng Technol. 2013 Apr;37(3):185-96. doi: 10.3109/03091902.2013.773097. Epub 2013 Apr 3.
Human tissue stiffness can vary due to different tissue conditions such as cancer tumours. Earlier studies show that stiffness may be detected with a resonance sensor that measures frequency shift and contact force at application. Through the frequency shift and the contact force, a tissue stiffness parameter can be derived. This study evaluated how the probe application angle and indentation velocity affected the results and determined the maximum parameter errors. The evaluation was made on flat silicone discs with specified hardness. The frequency shift, the force and the stiffness parameter all varied with contact angle and indentation velocity. A contact angle of ≤10° was acceptable for reliable measurements. A low indentation velocity was recommended. The maximum errors for the system were <1.1% of the measured values. It was concluded that contact angle and indentation velocity have to be considered in the clinical setting. The angular dependency is especially important in clinical use for studying stiffness of human soft tissue, e.g. in prostate cancer diagnosis.
人体组织的硬度会因不同的组织状况（如癌症肿瘤）而有所不同。早期研究表明，可以使用共振传感器检测硬度，该传感器在应用时测量频率偏移和接触力。通过频率偏移和接触力，可以推导出组织硬度参数。本研究评估了探头应用角度和压痕速度如何影响结果，并确定了最大参数误差。评估是在具有特定硬度的扁平硅胶圆盘上进行的。频率偏移、力和硬度参数均随接触角度和压痕速度而变化。对于可靠测量，≤10°的接触角是可接受的。建议采用低压痕速度。该系统的最大误差小于测量值的1.1%。得出的结论是，在临床环境中必须考虑接触角度和压痕速度。角度依赖性在临床用于研究人体软组织硬度（例如在前列腺癌诊断中）时尤为重要。
