Pilot Study of Smartphone Infrared Pupillography and Pupillometry

Figures & data

Table 1 Intraclass Correlation Coefficient for Pupillary Diameter Measurements When Using Computer and When Using Smartphone (n = 46)

	Computer Measurements			Smartphone Measurements
	ICC	95% CI	P	ICC	95% CI	p
Overall	0.995	0.992–0.997	<0.001*	0.984	0.975–0.991	<0.001*
1 vs 2	0.995	0.991–0.997	<0.001*	0.982	0.968–0.990	<0.001*
1 vs 3	0.995	0.991–0.997	<0.001*	0.985	0.974–0.992	<0.001*
2 vs 3	0.995	0.991–0.997	<0.001*	0.986	0.974–0.992	<0.001*

Note: *Statistically significant at P ≤ 0.05.

Abbreviations: CI, confidence interval; ICC, intraclass correlation coefficient.

Table 2 Comparison Between Desktop and Smartphone-Based Pupillary Diameter Measurements

	Desktop	Smartphone	T	P
Mean ± SD	4.27 ± 1.14	4.24 ± 1.12	1.169	0.248
Difference	0.03 ± 0.15

Note: t, Paired t-test; P, P value for comparing desktop and smartphone measurements.

Table 3 A Summary of Prior Reports of Smartphone Use in Pupillography and Pupillometry

	Visible Light Source	Infrared Light Source	Camera	Software	Hardware Add-on	Goal
Shin et al.^Citation4	Smartphone LED	None	Smartphone camera	Custom, iPhone-based	None	General pupillography
McAnany et al.^Citation8	Smartphone LED	None	Smartphone camera	Sensitometer™iPhone-based	None	General pupillometry
Neice et al.^Citation9	Smartphone LED	None	Smartphone camera	Custom, iPhone-based	None	Study of pupillary hippus in TBI
McKay et al.^Citation10	Smartphone LED	None	Smartphone camera	Commercially available iPhone application by BL; Brightlamp Inc., Indianapolis, IN, USA	None	General pupillometry
Mariakakis et al.^Citation5	Smartphone LED	None	Smartphone camera	iPhone-based trained convolutional neural networks	VR set-like 3D printed phone adapter	General pupillometry
Calandra et al.^Citation12	Smartphone LED	None	Smartphone camera	Sober-Eye application, iPhone-based	None	Self-assess pupillary reaction to light to identify drug/alcohol intoxication
Piaggio et al.^Citation13	Smartphone LED	None	Smartphone camera	Custom, Android-based	None	General pupillometry for low resource setting
Kim et al.^Citation15	White LED addons	Infrared LED addons	Smartphone camera	Custom, Android-based	White and infrared LEDs	General pupillometry
Chang et al.^Citation14	Smartphone LED	Externally powered infrared source	Infrared camera connected to a laptop	Custom laptop MATLAB	Slit lamp bound infrared camera, a laptop, and an infrared light source	General pupillography and pupillometry
Our design	External pen light source	Mini infrared source powered by the smartphone	Two synchronized minicameras connected to the smartphone	CameraFi smartphone app to capture videos/pictures Custom designed Pupil Gauge Smartphone application	Pocket size device consisting of 2 minicameras and mini-infrared light source	General pupillography and pupillometry

Figure 1 (A) Infrared camera module connected to smartphone. (B) Infrared camera module-smartphone complex mounted on slit lamp for steadier pupillography. Two mini-infrared cameras (arrows) and infrared light source (arrowhead) are shown.

Figure 2 Measurement of pupillary diameter of both eyes in dark (A) and in light (B) illumination conditions using our custom designed application in a patient with anisocoria.

Figure 3 Bland Altman plot and one sample t-test for agreement between smartphone and desktop-based measurements of pupillary diameter.

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