Department of Aeronautics and Astronautics, Massachusetts Institute of Technology, 77 Mass Ave., Cambridge, MA 02139, USA.
Physiol Meas. 2012 Jun;33(6):1027-42. doi: 10.1088/0967-3334/33/6/1027. Epub 2012 May 4.
Developments in photoplethysmography (PPG) hardware make this device a promising tool for non-invasive deep-tissue hemodynamic measurements. The aim of this study was to validate the use of PPG as a tool for non-invasive bone hemodynamic measurements. A new PPG device capable of measuring bone hemodynamic responses was designed, tested and validated. Validation experiments included cold exposure, arterial occlusion, skin occlusion and nitroglycerin exposure. Cold exposure resulted in a decrease in skin perfusion (p = 0.011) and bone perfusion (p = 0.005); arterial occlusion also resulted in decreased skin perfusion (p < 0.001) and bone perfusion (p = 0.008), with arterial occlusion resulting in a greater decrease in perfusion than cold exposure. The independence of the skin and bone PPG signals was demonstrated by the ability to independently increase (p = 0.003) and decrease (p = 0.005) the skin signal without significantly affecting the bone signal. Our experiments build upon and expand previous PPG developments and validation studies. Our custom-made PPG hardware represents a state-of-the-art tool for non-invasive monitoring of deep tissues, and our data support the use of PPG as a valid tool for measuring bone hemodynamic responses in vivo.
光电容积脉搏波（PPG）硬件的发展使该设备成为非侵入性深部组织血液动力学测量的有前途的工具。本研究旨在验证 PPG 作为一种非侵入性骨血液动力学测量工具的用途。设计、测试和验证了一种新的能够测量骨血液动力学响应的 PPG 设备。验证实验包括冷暴露、动脉闭塞、皮肤闭塞和硝化甘油暴露。冷暴露导致皮肤灌注（p = 0.011）和骨灌注（p = 0.005）减少；动脉闭塞也导致皮肤灌注（p < 0.001）和骨灌注（p = 0.008）减少，动脉闭塞导致的灌注减少大于冷暴露。皮肤和骨 PPG 信号的独立性通过能够独立增加（p = 0.003）和减少（p = 0.005）皮肤信号而不会显著影响骨信号来证明。我们的实验建立在以前的 PPG 开发和验证研究的基础上并进行了扩展。我们的定制 PPG 硬件代表了一种用于非侵入性监测深部组织的最先进工具，并且我们的数据支持将 PPG 用作测量体内骨血液动力学反应的有效工具。
