Anytime, Anywhere Nystagmus Observation Compact and easy to use, the F-Loupe with Fresnel. Lens enhances the visibility of subtle nystagmus in clinical practice—no power source required, and ideal for bright environments. • Provides compact convenience for any location • Supports use in emergency rooms, field clinics, and training • Offers an affordable, reliable option to powered devices • Blocks visual fixation to enhance nystagmus visibility • Magnifies eye movements with a 2x Fresnel lens • Weights only 24g - ultra-light and easy to carry _ mf-- _ m DAIICHI MEDICAL CO., LTD. wwn.first-med.co.jp/en E/V I f llsl 2-27-16, Hongo, Bunkyo-ku, 113-0033, Tokyo, Japan Phone: (SI) 3-3814-0111 Fax: (81) 3-3814-0135 Email: international'2g.first-med.co.jp Color on printed materials differ from color of actual product. Design and specifications are subject to change without prior notice.

Tsunoda et al. International Journal of Emergency Medicine https://doi.org/10.1186/s12245-024-00791-2 International Journal of Emergency Medicine Open Access New Fresnel lens loupe for nystagmus observation suitable for use by medical staff in emergency departments Reiko Tsunoda1,2*, Yumi Dobashi1, Masao Noda1,3 and Hiroaki Fushiki1,2 Abstract Background Reduction of spontaneous nystagmus by fixation, a characteristic feature of peripheral nystagmus, is important for differentiating between peripheral and central vestibular disorders. In the emergency room, Frenzel goggles are recommended to...

Tsunoda et al. International Journal of Emergency Medicine Background Peripheral vestibular disorders are the most common cause of vertigo; however, at diagnosis, central disorders must be ruled out. The Head Impulse, Nystagmus, Test of Skew (HINTS) and the STANDING algorithm are well known bedside tests for differentiating between central and peripheral dizziness in patients with acute vestibular syndrome [1–3]. However, the accuracy of the results of the HINTS examination administered by emergency physicians is lower than that achieved by neurologists and otolaryngologists [4, 5]. A study investigating...

Tsunoda et al. International Journal of Emergency Medicine Fig. 1 Portable loupe based on the Fresnel lens. (a) The size of the loupe when the lens is in the storage cover is 90 × 90 × 10 mm. (b) The dimensions of the loupe when in use are 160 × 90 × 10 mm. (c) Its storage size is appropriate for covering one eye in the test of skew darkened, and the lights inside the goggles were turned on (Fig. 2a). When using the loupe, the right eye was covered with a Fresnel lens, and the left eye with a storage cover, with the ceiling-light on (Fig. 2b). Each participant underwent caloric test for both...

Tsunoda et al. International Journal of Emergency Medicine Fig. 2 Participants’ eyes when using the nystagmus observation tools. (a) When using Frenzel goggles, the room remains darkened, and the lights inside the goggles are turned on. (b) When using the loupe, the ceiling light is turned on, the right eye is covered by the lens and the left eye is covered with the storage cover

Tsunoda et al. International Journal of Emergency Medicine Fig. 3 Electronystagmography during the active phase of caloric nystagmus. Black arrow, 30 s after the end of the stimulus. In the complete darkness condition, the mean slow-phase velocity (SPV) of nystagmus was measured 25–30 s after the end of the stimulus. (a) For the Frenzel goggles (Frenzel), the mean SPV was measured 5–10 s after applying the Frenzel goggles. (b) For the loupe, mean SPV was measured 5–10 s after applying the loupe Fig. 4 Electronystagmography during the decay phase of caloric nystagmus. Black arrow, 60 s after the...

Tsunoda et al. International Journal of Emergency Medicine Table 1 Mean SPV and VIS of the loupe vs. the Frenzel Tool Ears Mean SPV of Mean SPV VIS Mean dif- complete of mean ference darkness using tool (SD) in VIS Data are presented as the mean (standard deviation) and mean difference in VIS (95% confidence interval) SPV, slow-phase velocity (deg/s); SD, standard deviation; Frenzel, Frenzel goggles; VIS, visual impact susceptibility; mean difference in VIS, mean difference in VIS between the loupe and Frenzel; 95%CI, 95% confidence interval Concomitant with the ENG recording, nystagmus was recorded...

Tsunoda et al. International Journal of Emergency Medicine because the ceiling lights are turned on when using the loupe, and when using Frenzel goggles, the room is dark but the lights inside the goggles are turned on. We were the first to introduce VIS to assess the visual impact of the tools in this study, based on the method of the visual suppression test [11]. VIS, which was described as the ratio of the mean SPV during the use of the nystagmus observation tool to the maximum SPV, was considered appropriate for assessing the impact of vision. Furthermore, nystagmus, which was weakened in...

2. Gottlieb M, Peksa GD, Carlson JN. Head impulse, nystagmus, and test of skew examination for diagnosing central causes of acute vestibular syndrome. Cochrane Database Syst Rev. 2023;11:CD015089. 3. Gerlier C, Hoarau M, Fels A, Vitaux H, Mousset C, Farhat W, et al. Differentiating central from peripheral causes of acute vertigo in an emergency setting with the HINTS, STANDING, and ABCD2 tests: a diagnostic cohort study. Acad Emerg Med. 2021;28:1368-78. 4. Dmitriew C, Regis A, Bodunde O, Lepage R, Turgeon Z, Mclsaac S, et al. Diagnostic accuracy of the HINTS exam in an emergency department: a...