PURPOSE: The purpose of this virtual analysis study was to compare the accuracy and precision of 3-dimensional (3D) ear models generated by scanning gypsum casts with a smartphone camera and a desktop laser scanner.
MATERIAL AND METHODS: Six ear casts were fabricated from green dental gypsum and scanned with a laser scanner. The resultant 3D models were exported as standard tessellation language (STL) files. A stereophotogrammetry system was fabricated by using a motorized turntable and an automated microcontroller photograph capturing interface. A total of 48 images were captured from 2 angles on the arc (20 degrees and 40 degrees from the base of the turntable) with an image overlap of 15 degrees, controlled by a stepper motor. Ear 1 was placed on the turntable and captured 5 times with smartphone 1 and tested for precision. Then, ears 1 to 6 were scanned once with a laser scanner and with smartphones 1 and 2. The images were converted into 3D casts and compared for accuracy against their laser scanned counterparts for surface area, volume, interpoint mismatches, and spatial overlap. Acceptability thresholds were set at <0.5 mm for interpoint mismatches and >0.70 for spatial overlap.
RESULTS: The test for smartphone precision in comparison with that of the laser scanner showed a difference in surface area of 774.22 ±295.27 mm2 (6.9% less area) and in volume of 4228.60 ±2276.89 mm3 (13.4% more volume). Both acceptability thresholds were also met. The test for accuracy among smartphones 1, 2, and the laser scanner showed no statistically significant differences (P>.05) in all 4 parameters among the groups while also meeting both acceptability thresholds.
CONCLUSIONS: Smartphone cameras used to capture 48 overlapping gypsum cast ear images in a controlled environment generated 3D models parametrically similar to those produced by standard laser scanners.
DESIGN: Part 1 involved electroacoustic measurement and biological calibration of a laptop-earphone pair used for the computer-based audiometry (CBA). Part 2 compared CBA thresholds obtained without a sound booth with those measured using the gold-standard clinical audiometry.
STUDY SAMPLE: 17 young normal-hearing volunteers (Part 1) and 43 normal and hearing loss subjects (Part 2) recruited from an audiology clinic via convenience sampling.
RESULTS: The transducer-device combination produced outputs suitable for measuring thresholds down to 0 dB HL. Threshold pairs obtained from the CBA and clinical audiometry were highly correlated (Spearman's correlation coefficient, ρ = 0.92, p 25 dB HL.
CONCLUSIONS: The use of a computer-based audiometer application with consumer insert phone-earmuff combination can offer a cost-effective solution for boothless screening audiometry.
METHODS: A randomized controlled trial was conducted in the antenatal clinic of University Malaya Medical Centre from June 2021 to June 2022. Women at 34-36 weeks gestation with self-reported night sleep duration ≤6 hours were recruited. Participants wore an actigraphy device at night for seven consecutive nights (Observation/Baseline week). Only women whose actigraphy-derived night sleep duration was confirmed to be ≤360 minutes were randomized to use EMEP or AL. Actigraphy was continued for another week (Intervention week). Primary outcome was change in actigraphy-derived night sleep duration from observation to intervention week across trial arms. Secondary outcomes include participants' sleep quality, labor, and neonatal outcome. Comparisons were by Student t-test, Mann-Whitney U test, and chi-square test.
RESULTS: A total of 210 women were randomized: 105 each to EMEP and AL. The increase in night sleep duration over baseline was significantly longer with both EMEP (mean ± SD) 23 ± 41 minutes, p