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Clin Ophthalmol. 2017 May 19;11:939-944. doi: 10.2147/OPTH.S135128. eCollection 2017.

Novel positioning sensor with real-time feedback for improved postoperative positioning: pilot study in control subjects.

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Department of Ophthalmology, University of California San Francisco, San Francisco, CA, USA.
School of Medicine, University of California San Francisco, San Francisco, CA, USA.
Department of Medical Engineering, California Institute of Technology, Pasadena, CA, USA.



Repair of retinal detachment frequently requires use of intraocular gas. Patients are instructed to position themselves postoperatively to appose the intraocular bubble to the retinal break(s). We developed a novel wearable wireless positioning sensor, which provides real-time audiovisual feedback on the accuracy of positioning.


Eight healthy volunteers wore the wireless sensor for 3 hours while instructed to maintain their head tilted toward the 2 o'clock meridian with no audiovisual feedback. Positioning accuracy was recorded. The subjects repeated the experiment for 3 hours with the audiovisual feedback enabled.


With no audiovisual feedback, the percentage of time greater than 10° out of position varied from 8.9% to 93.9%. With audiovisual feedback enabled, these percentages ranged from 9.4% to 65%. Three subjects showed significant improvement in their time out of position (P<0.01, Fisher's exact test). Four subjects demonstrated a nonsignificant improvement, and one subject had a significant increase in time out of position with feedback (P<0.01). When pooled, all subjects demonstrated a statistically significant decrease in degrees out of position (P<0.001, Wilcoxon test) and a statistically significant improvement in total time out of position (P<0.001).


The novel positioning sensor showed improved positioning compliance in half of the healthy volunteers during our short pilot study. Other subjects derived little benefit from the feedback. The causes for this observation are unclear. However, given the significant improvement as a group, this new technology could be beneficial to patients who struggle with postoperative positioning.


device; intraocular gas; macular hole; pneumatic retinopexy; postoperative positioning; retinal detachment; vitrectomy

Conflict of interest statement

Disclosure The authors report no conflicts of interest in this work.

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