Remer Itay, Bilenca Alberto
Biomedical Engineering Department, Ben-Gurion University of the Negev, 1 Ben Gurion Blvd, Be'er-Sheva, 84105, Israel.
Ilse Katz Institute for Nanoscale Science and Technology, Ben-Gurion University of the Negev, 1 Ben Gurion Blvd, Be'er-Sheva, 84105, Israel.
J Biophotonics. 2015 Nov;8(11-12):902-7. doi: 10.1002/jbio.201500156. Epub 2015 Apr 23.
Photoplethysmography is a well-established technique for the noninvasive measurement of blood pulsation. However, photoplethysmographic devices typically need to be in contact with the surface of the tissue and provide data from a single contact point. Extensions of conventional photoplethysmography to measurements over a wide field-of-view exist, but require advanced signal processing due to the low signal-to-noise-ratio of the photoplethysmograms. Here, we present a noncontact method based on temporal sampling of time-integrated speckle using a camera-phone for noninvasive, widefield measurements of physiological parameters across the human fingertip including blood pulsation and resting heart-rate frequency. The results show that precise estimation of these parameters with high spatial resolution is enabled by measuring the local temporal variation of speckle patterns of backscattered light from subcutaneous skin, thereby opening up the possibility for accurate high resolution blood pulsation imaging on a camera-phone. Camera-phone laser speckle imager along with measured relative blood perfusion maps of a fingertip showing skin perfusion response to a pulse pressure applied to the upper arm. The figure is for illustration only; the imager was stabilized on a stand throughout the experiments.
光电容积脉搏波描记法是一种成熟的用于无创测量血液搏动的技术。然而，光电容积脉搏波描记设备通常需要与组织表面接触，并从单个接触点提供数据。虽然存在将传统光电容积脉搏波描记法扩展到宽视场测量的方法，但由于光电容积脉搏波图的信噪比低，需要先进的信号处理。在此，我们提出一种基于使用手机相机对时间积分散斑进行时间采样的非接触方法，用于对包括血液搏动和静息心率频率在内的人体指尖生理参数进行无创、宽视场测量。结果表明，通过测量皮下皮肤背向散射光散斑图案的局部时间变化，能够以高空间分辨率精确估计这些参数，从而为在手机相机上进行精确的高分辨率血液搏动成像开辟了可能性。手机相机激光散斑成像仪以及测得的指尖相对血液灌注图，显示了皮肤对施加于上臂的脉压的灌注反应。该图仅用于说明；在整个实验过程中，成像仪固定在支架上。
