The accuracy of image-based safety analysis for robotic cochlear implantation.

PURPOSE: To evaluate the accuracy and reliability of image-based safety analysis for robotic cochlear implantation (RCI) in an ex vivo assessment. METHODS: The accuracy was evaluated in a study on 23 human temporal bones. For image analysis, a computer-assisted safety analysis based on intraoperative cone beam computed tomography was implemented. The method automatically segments the drill tunnel and predicts the distance between the tunnel and the facial nerve. In addition, the drilling error at the target is predicted. The predicted distances were compared with the actually drilled distances measured in postoperative high-resolution micro-computed tomography scans. The automatic method was compared to accuracies associated with a manual analysis of the image data. RESULTS: The presented computerized image-based analysis enabled the proximity of the facial nerve to the drill trajectory to be predicted with an accuracy of 0.22 ± 0.15 mm and drilling error at the target to be predicted with an accuracy of 0.11 mm ± 0.08 during N = 19 RCI procedures. The manual assessment of facial nerve proximity was performed with an accuracy of 0.34 ± 0.20 mm by a trained clinical expert. CONCLUSION: The assessment of intraoperative CT-based imaging presents multiple benefits over alternative safety mechanisms including early detection and applicability even in cases of malformation of the mastoid. This work presents a computer-assisted approach to image analysis that enables procedure safety measurements to be reliably performed with superior accuracy to other proposed safety methodologies, at a safe distance from the facial nerve. Its application must, however, be considered in relation to associated costs (time, cost, irradiation) and the dependence of the measure on a reliable preoperative segmentation.

Remembering mnemonics: a three-year follow-up on the effects of mnemonics training in elderly adults.

The purpose of this study was to assess the long-term impact of providing training in mnemonics to a small group of elderly adults. We wished to determine if such training could be utilized effectively some three years (34 months) after initial training. Nine of ten original subjects consented to take part in the retesting exercise. Ages ranged from 66 to 85 yrs (M = 73.5). Our results demonstrate that though loci generally were available for use in remembering a new word list, they usually were not effectively utilized to enhance recall. Our participants also agreed that the training they had received was useful. In spite of this, a majority of the respondents did not use the method of loci after training. However, adults of all ages often do not utilize mnemonics training once its effectiveness has been demonstrated. Therefore, creating effective cognitive interventions may require that we adopt techniques that have been shown to improve compliance in other areas of healthy living.

Maintenance and generalization of mnemonics for grocery shopping by older adults.

This study was designed to assess the impact and generalization of mnemonics training in older adults. We attempted to maximize the task's ecological validity and the motivation of participants. Ten older adults were initially tested in a standard free recall task. All participants were next trained to use the method of loci. This technique was then used to remember a grocery list while purchasing groceries. Four weeks later, a second grocery shopping test was conducted. After another four weeks, a second free recall test was given. Participants' memory performance was recorded in each activity and they reported mnemonic strategies they had used. Participants exhibited near perfect performance in the grocery shopping tasks, but many modified their strategies before the second shopping session. Participants who did not modify their strategies were more likely to exhibit long term maintenance of training (retention of strategy and improved performance) in the final free recall task. Factors associated with changes in a training program's impact over time, and the need to survey participants' reported strategy utilization, are discussed.