Driving Safety and Real-Time Glucose Monitoring in Insulin-Dependent Diabetes

Abstract

Our goal is to address the need for driver-state detection using wearable and in-vehicle sensor measurements of driver physiology and health. To address this goal, we deployed in-vehicle systems, wearable sensors, and procedures capable of quantifying real-world driving behavior and performance in at-risk drivers with insulin-dependent type 1 diabetes mellitus (DM). We applied these methodologies over 4 weeks of continuous observation to quantify differences in real-world driver behavior profiles associated with physiologic changes in drivers with DM (N=19) and without DM (N=14). Results showed that DM driver behavior changed as a function of glycemic state, particularly hypoglycemia. DM drivers often drive during at-risk physiologic states, possibly due to unawareness of impairment, which in turn may relate to blunted physiologic responses (measurable heart rate) to hypoglycemia after repeated episodes of hypoglycemia. We found that this DM driver cohort has an elevated risk of crashes and citations, which our results suggest is linked to the DM driver's own momentary physiology. Overall, our findings demonstrate a clear link between at-risk driver physiology and real-world driving. By discovering key relationships between naturalistic driving and parameters of contemporaneous physiologic changes, like glucose control, this study directly advances the goal of driver-state detection through wearable physiologic sensors as well as efforts to develop "gold standard" metrics of driver safety and an individualized approach to driver health and wellness.

Keywords: CGM; Safety [C1]; diabetes; driver behavior; driver physiology; driver safety; driver state detection; human engineering [C2]; naturalistic driving.

Figures

Fig. 1

The risk of driver errors depends on arousal and attention, perception, response selection and implementation (which depends on memory, decision-making and other executive functions), emotion, motor abilities, and awareness of behavior and internal status. The driver’s behavior is safe or unsafe due to errors at one or more stages in the driving task. Glucose levels affect processing at several stages.

Fig. 2

Frequency of DM Driver Exposure to Glucose Levels throughout Study Participation.

Fig. 3

Frequency of DM Driving at Varying Glucose Levels

Fig. 4

Vehicle Acceleration Variability in DM Drivers with Varying Glycemic States and Comparison Drivers. DM drivers showed significant changes in vehicle acceleration variability relative to comparison drivers. These changes increased during at-risk glycemic states and during high speed driving.

Fig. 5

Changes in Individual DM Driver’s Acceleration Variability as a Function of his or her own Glycemic State. DM drivers showed significant changes in vehicle acceleration behavior relative to their own driving at changing glycemic states.

Fig. 6

Acceleration Event Rates as a Function of the DM Driver’s In-Vehicle Glucose Levels and Vehicle Speed. Acceleration event rates significantly increased as the DM driver’s glucose levels fell. Event rates further increased during higher speed driving.

Fig. 7

A Severely Hypoglycemic (