Prager Ross, Pageau Paul, Hodges Timothy, Yan Christina, Woo Michael, Nemnom Marie-Joe, Millington Scott, Holden Matthew, St-Gelais Raphael, Cheung Warren J
Department of Medicine University of Ottawa Ottawa Ontario Canada.
Department of Emergency Medicine University of Ottawa Ottawa Ontario Canada.
AEM Educ Train. 2022 Apr 1;6(2):e10733. doi: 10.1002/aet2.10733. eCollection 2022 Apr.
Point-of-care ultrasound (POCUS) has become an important diagnostic tool in acute care medicine; however, little is known about the biomechanical differences between novice and expert practitioners.
A low-cost ($50 CAD) gyroscope and accelerometer integrated sensor was assembled and affixed to an ultrasound probe. Seventeen participants, nine novices and eight experts, were recruited to perform three abdominal and four cardiac scans on a standardized patient. Participant demographics, time per scan, average acceleration, average angular velocity, decay in acceleration and angular velocity over time, and frequency of probe movements were analyzed. Video capture with blinded video review was scored.
On video review, experts had higher image optimization and acquisition scores for both abdominal and cardiac scans. Experts had shorter scan times for abdominal (7 s vs. 26 s, = 0.003) and cardiac (11 s vs. 26 s, < 0.001) scans. There was no difference in average acceleration () between novices and experts performing abdominal (1.02 vs. 1.01, = 0.50) and cardiac (1.01 vs. 1.01, = 0.45) scans. Experts had lower angular velocity (°/s) for abdominal scans (10.00 vs. 18.73, < 0.001) and cardiac scans (15.61 vs. 20.33, = 0.02) There was a greater decay in acceleration over time for experts performing cardiac scans compared to novices (-0.194 vs. -0.050, = 0.03) but not for abdominal scans or when measuring angular velocity. The frequency of movements (Hz) was higher for novices compared to experts for abdominal (16.68 vs. 13.79, < 0.001) and cardiac (17.60 vs. 13.63, = 0.002) scans.
This study supports the feasibility of a low-cost gyroscope and accelerometer integrated sensor to quantify the biomechanics of POCUS. It may also support the concept of "window shopping" as a method by which experts obtain abdominal and cardiac views, where sliding is used to find an acoustic window, then smaller rocking and tilting probe movements are used to refine the image.
床旁超声（POCUS）已成为急性护理医学中的一项重要诊断工具；然而，对于新手和专家从业者之间的生物力学差异知之甚少。
组装了一个低成本（50加元）的陀螺仪和加速度计集成传感器，并将其固定在超声探头上。招募了17名参与者，其中9名新手和8名专家，对一名标准化患者进行三次腹部扫描和四次心脏扫描。分析了参与者的人口统计学数据、每次扫描的时间、平均加速度、平均角速度、加速度和角速度随时间的衰减以及探头移动频率。通过盲法视频回顾对视频采集进行评分。
在视频回顾中，专家在腹部和心脏扫描的图像优化和采集评分方面更高。专家进行腹部扫描（7秒对26秒，P = 0.003）和心脏扫描（11秒对26秒，P < 0.001）的时间更短。在进行腹部（1.02对1.01，P = 0.50）和心脏（1.01对1.01，P = 0.45）扫描时，新手和专家的平均加速度没有差异。专家进行腹部扫描（10.00对18.73，P < 0.001）和心脏扫描（15.61对20.33，P = 0.02）时的角速度较低。与新手相比，专家进行心脏扫描时加速度随时间的衰减更大（-0.194对-0.050，P = 0.03），但腹部扫描或测量角速度时并非如此。新手进行腹部（16.68对13.79，P < 0.001）和心脏（17.60对13.63，P = 0.002）扫描时的移动频率高于专家。
本研究支持使用低成本的陀螺仪和加速度计集成传感器来量化POCUS生物力学的可行性。它也可能支持“窗口搜索”的概念，即专家获取腹部和心脏视图的一种方法，通过滑动找到声学窗口，然后使用较小的摇摆和倾斜探头移动来优化图像。
