Department of Anesthesiology, Pharmacology & Therapeutics, The University of British Columbia, Vancouver, BC, Canada.
Anesth Analg. 2012 Sep;115(3):588-94. doi: 10.1213/ANE.0b013e31825d638c. Epub 2012 Jun 13.
Vibro-tactile displays use human skin to convey information from physiological monitors to anesthesiologists, providing cues about changes in the status of the patient. In this investigation, we evaluated, in a real-time clinical environment, the usability and wearability of a novel vibro-tactile display belt recently developed by our group, and determined its accuracy in identifying events when used by anesthesiologists.
A prospective observational study design was used. During routine anesthesia, a standard physiological monitor was connected to a software tool that used algorithms to automatically identify changing trends in mean noninvasive arterial blood pressure, expired minute ventilation, peak airway pressure, and end-tidal carbon dioxide partial pressure. The software was wirelessly interfaced to a vibro-tactile belt worn by the anesthesiologist. Each physiological variable was mapped to 1 of 4 tactor locations within the belt. The direction (increase/decrease) and 2 levels of change (small/large) were encoded in the stimulation patterns. A training session was completed by each anesthesiologist. The system was activated in real-time during anesthesia alongside routine physiological monitors. When the algorithms detected changes in the patient, the belt vibrated at the appropriate location with the pattern corresponding to the level and direction of change. Using a touch screen monitor the anesthesiologist was to enter the vibro-tactile message by first identifying the variable, then identifying the level and direction of change. Usability and wearability questionnaires were to be completed. The percentage of correct identification of the physiological trend, the direction of change, and the level of change were primary outcome variables. The mean usability score and wearability results were secondary outcome variables. We hypothesized that anesthesiologists would correctly identify the events communicated to them through the vibro-tactile belt 90% of the time, and that anesthesiologists would find the vibro-tactile belt usable and wearable.
Seventeen anesthesiologists evaluated the display during 57 cases. The belt was operational for a mean (SD) duration of 75 (41) minutes per case. Seven cases were excluded from analysis because of technical failures. Eighty-one percent (confidence interval [CI], 77% to 84%) of all stimuli were decoded. The physiological trend, the direction of change, and the level of change were correctly identified for 97.7% (CI 96%-99%), 94.9% (CI 92%-97%), and 93.5% of these stimuli (CI, 91%-96%), respectively. Fourteen anesthesiologists completed the usability and wearability questionnaires. The mean usability score was 4.8 of a maximum usability score of 7.
Anesthesiologists found a vibro-tactile belt to be wearable and usable and could accurately decode vibro-tactile messages in a real-time clinical environment.
振动触觉显示器利用人体皮肤将生理监测器的信息传达给麻醉师，为患者的状态变化提供线索。在这项研究中，我们在实时临床环境中评估了我们小组最近开发的新型振动触觉腰带的可用性和可穿戴性，并确定了麻醉师使用时识别事件的准确性。
采用前瞻性观察研究设计。在常规麻醉期间，将标准生理监测器连接到一个软件工具，该工具使用算法自动识别平均无创动脉血压、呼气分钟通气量、气道峰压和呼气末二氧化碳分压的变化趋势。软件通过无线接口与麻醉师佩戴的振动触觉腰带连接。每个生理变量都映射到腰带内的 4 个传感器位置之一。刺激模式编码了方向（增加/减少）和 2 个变化水平（小/大）。每位麻醉师都完成了一个培训课程。系统在麻醉期间与常规生理监测器一起实时激活。当算法检测到患者的变化时，腰带会在适当的位置振动，并带有与变化水平和方向相对应的模式。麻醉师通过首先识别变量，然后识别变化的水平和方向，使用触摸屏监视器输入振动触觉信息。完成可用性和可穿戴性问卷。正确识别生理趋势、变化方向和变化水平的百分比是主要结果变量。平均可用性评分和可穿戴性结果是次要结果变量。我们假设，麻醉师通过振动触觉带识别传达给他们的事件的正确率为 90%，并且麻醉师会发现振动触觉带是可用的和可穿戴的。
17 名麻醉师在 57 例中评估了该显示器。每条腰带在每个病例中的平均（SD）运行时间为 75（41）分钟。由于技术故障，有 7 例被排除在分析之外。81%（置信区间[CI]，77%至 84%）的所有刺激都被解码。生理趋势、变化方向和变化水平的正确识别率分别为 97.7%（CI 96%至 99%）、94.9%（CI 92%至 97%）和 93.5%（CI 91%至 96%）。14 名麻醉师完成了可用性和可穿戴性问卷。平均可用性评分为 7 分制的 4.8 分。
麻醉师发现振动触觉带是可穿戴的且可用的，并且可以在实时临床环境中准确解码振动触觉信息。
