Three-dimensional (3D) ultrasonic imaging can enable post-facto plane of interest selection. It can be performed with devices such as wobbler probes, matrix probes, and sensor-based probes. Ultrasound systems that support 3D-imaging are expensive with added hardware complexity compared to 2D-imaging systems. An inertial measurement unit (IMU) can potentially be used for 3D-imaging by using it to track the motion of a one-dimensional array probe and constraining its motion in one degree of freedom (1-DoF) rotation (swept-fan). This work demonstrates the feasibility of an affordable IMU-assisted manual 3D-ultrasound scanner (IAM3US). A consumer-grade IMU-assisted 3D scanner prototype is designed with two support structures for swept-fan. After proper IMU calibration, an appropriate KF-based algorithm estimates the probe orientation during the swept-fan. An improved scanline-based reconstruction method is used for volume reconstruction. The evaluation of the IAM3US system is done by imaging a tennis ball filled with water and the head region of a fetal phantom. From fetal phantom reconstructed volumes, suitable 2D planes are extracted for biparietal diameter (BPD) manual measurements. Later, in-vivo data is collected. The novel contributions of this paper are (1) the application of a recently proposed algorithm for orientation estimation of swept-fan for 3D imaging, chosen based on the noise characteristics of selected consumer grade IMU (2) assessment of the quality of the 1-DoF swept-fan scan with a deflection detector along with monitoring of maximum angular rate during the scan and (3) two probe holder designs to aid the operator in performing the 1-DoF rotational motion and (4) end-to-end 3D-imaging system-integration. Phantom studies and preliminary in-vivo obstetric scans performed on two patients illustrate the usability of the system for diagnosis purposes.

中文翻译：

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使用运动约束扫频扇形扫描的 IMU 辅助手动 3D 超声成像

三维 (3D) 超声成像可以实现事后感兴趣平面的选择。它可以使用摆动探头、矩阵探头和基于传感器的探头等设备来执行。与 2D 成像系统相比，支持 3D 成像的超声系统价格昂贵，而且硬件复杂性也更高。惯性测量单元 (IMU) 可用于跟踪一维阵列探头的运动并将其运动约束在一个自由度 (1-DoF) 旋转（扫描扇形）中，从而可用于 3D 成像。这项工作展示了经济实惠的 IMU 辅助手动 3D 超声扫描仪 (IAM3US) 的可行性。消费级 IMU 辅助 3D 扫描仪原型设计有两种扫扇支撑结构。正确的 IMU 校准后，适当的基于 KF 的算法会估计扫扇期间的探头方向。一种改进的基于扫描线的重建方法用于体积重建。 IAM3US 系统的评估是通过对充满水的网球和胎儿模型的头部区域进行成像来完成的。从胎儿体模重建体积中，提取合适的二维平面用于双顶径 (BPD) 手动测量。随后，收集体内数据。本文的新颖贡献是 (1) 应用最近提出的用于 3D 成像的扫扇方向估计的算法，该算法是根据所选消费级 IMU 的噪声特性进行选择的 (2) 1- 质量评估使用偏转探测器进行 DoF 扫频扇形扫描，并监控扫描期间的最大角速率；(3) 两个探头支架设计可帮助操作员执行 1-DoF 旋转运动；(4) 端到端 3D-成像系统集成。对两名患者进行的模型研究和初步体内产科扫描说明了该系统用于诊断目的的可用性。