Accurate non-invasive assessment of tissue elasticity in vivo is required for early diagnostics of many tissue abnormalities. We have developed a focused air-pulse system that produces a low-pressure and short-duration air stream, which can be used to excite transient surface waves (SWs) in soft tissues. System characteristics were studied using a high-resolution analog pressure transducer to describe the excitation pressure. Results indicate that the excitation pressure provided by the air-pulse system can be easily controlled by the air source pressure, the angle of delivery, and the distance between the tissue surface and the port of the air-pulse system. Furthermore, we integrated this focused air-pulse system with phase-sensitive optical coherence tomography (PhS-OCT) to make non-contact measurements of tissue elasticity. The PhS-OCT system is used to assess the group velocity of SW propagation, which can be used to determine Young's modulus. Pilot experiments were performed on gelatin phantoms with different concentrations (10%, 12% and 14% w/w). The results demonstrate the feasibility of using this focused air-pulse system combined with PhS-OCT to estimate tissue elasticity. This easily controlled non-contact technique is potentially useful to study the biomechanical properties of ocular and other tissues in vivo.

中文翻译：

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基于光学相干断层扫描的组织弹性测量的聚焦空气脉冲系统

许多组织异常的早期诊断需要对体内组织弹性进行准确的非侵入性评估。我们开发了一种聚焦空气脉冲系统，可产生低压和持续时间短的气流，可​​用于激发软组织中的瞬态表面波 (SW)。使用高分辨率模拟压力传感器来描述激励压力来研究系统特性。结果表明，空气脉冲系统提供的激发压力可以很容易地通过气源压力、输送角度以及组织表面与空气脉冲系统端口之间的距离来控制。此外，我们将这种聚焦空气脉冲系统与相敏光学相干断层扫描 (PhS-OCT) 集成在一起，以非接触式测量组织弹性。PhS-OCT 系统用于评估 SW 传播的群速度，可用于确定杨氏模量。对不同浓度（10%、12% 和 14% w/w）的明胶幻影进行了试点实验。结果证明了使用这种聚焦空气脉冲系统结合 PhS-OCT 来估计组织弹性的可行性。这种易于控制的非接触式技术可能有助于研究体内眼部和其他组织的生物力学特性。