Purpose

Augmented reality (AR) and head-mounted displays (HMD) in medical practice are current research topics. A commonly proposed use case of AR-HMDs is to display data in image-guided interventions. Although technical feasibility has been thoroughly shown, effects of AR-HMDs on interventions are not yet well researched, hampering clinical applicability. Therefore, the goal of this study is to better understand the benefits and limitations of this technology in ultrasound-guided interventions.

Methods

We used an AR-HMD system (based on the first-generation Microsoft Hololens) which overlays live ultrasound images spatially correctly at the location of the ultrasound transducer. We chose ultrasound-guided needle placements as a representative task for image-guided interventions. To examine the effects of the AR-HMD, we used mixed methods and conducted two studies in a lab setting: (1) In a randomized crossover study, we asked participants to place needles into a training model and evaluated task duration and accuracy with the AR-HMD as compared to the standard procedure without visual overlay and (2) in a qualitative study, we analyzed the user experience with AR-HMD using think-aloud protocols during ultrasound examinations and semi-structured interviews after the task.

Results

Participants (n = 20) placed needles more accurately (mean error of 7.4 mm vs. 4.9 mm, p = 0.022) but not significantly faster (mean task duration of 74.4 s vs. 66.4 s, p = 0.211) with the AR-HMD. All participants in the qualitative study (n = 6) reported limitations of and unfamiliarity with the AR-HMD, yet all but one also clearly noted benefits and/or that they would like to test the technology in practice.

Conclusion

We present additional, though still preliminary, evidence that AR-HMDs provide benefits in image-guided procedures. Our data also contribute insights into potential causes underlying the benefits, such as improved spatial perception. Still, more comprehensive studies are needed to ascertain benefits for clinical applications and to clarify mechanisms underlying these benefits.

中文翻译：

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增强现实中的超声：图像引导干预中头戴式显示器的混合方法评估。

目的

医疗实践中的增强现实 (AR) 和头戴式显示器 (HMD) 是当前的研究课题。AR-HMD 的一个常见用例是在图像引导干预中显示数据。尽管技术可行性已得到充分证明，但 AR-HMD 对干预的影响尚未得到充分研究，这阻碍了临床适用性。因此，本研究的目标是更好地了解该技术在超声引导干预中的优势和局限性。

方法

我们使用了 AR-HMD 系统（基于第一代 Microsoft Hololens），该系统在超声换能器的位置正确地在空间上叠加实时超声图像。我们选择超声引导的针头放置作为图像引导干预的代表性任务。为了检查 AR-HMD 的效果，我们使用混合方法并在实验室环境中进行了两项研究：(1) 在随机交叉研究中，我们要求参与者将针头放入训练模型中，并使用AR-HMD 与没有视觉叠加的标准程序相比，以及 (2) 在一项定性研究中，我们在超声检查和任务后的半结构化访谈期间使用大声思考协议分析了 AR-HMD 的用户体验。

结果

参与者 ( n  = 20) 更准确地放置针头（平均误差为 7.4 毫米与 4.9 毫米，p  = 0.022）但没有显着更快（平均任务持续时间为 74.4 秒与 66.4 秒，p  = 0.211）与 AR-HMD . 定性研究的所有参与者( n  = 6) 都报告了 AR-HMD 的局限性和不熟悉，但除了一个人之外，所有人都清楚地指出了好处和/或他们希望在实践中测试该技术。

结论

我们提供了额外的但仍然是初步的证据，证明 AR-HMD 在图像引导程序中提供了好处。我们的数据还有助于深入了解潜在好处的潜在原因，例如改善空间感知。尽管如此，还需要更全面的研究来确定临床应用的益处并阐明这些益处的潜在机制。