Wearable Sensors for Monitoring of Cigarette Smoking in Free-Living: A Systematic Review

Abstract

Globally, cigarette smoking is widespread among all ages, and smokers struggle to quit. The design of effective cessation interventions requires an accurate and objective assessment of smoking frequency and smoke exposure metrics. Recently, wearable devices have emerged as a means of assessing cigarette use. However, wearable technologies have inherent limitations, and their sensor responses are often influenced by wearers' behavior, motion and environmental factors. This paper presents a systematic review of current and forthcoming wearable technologies, with a focus on sensing elements, body placement, detection accuracy, underlying algorithms and applications. Full-texts of 86 scientific articles were reviewed in accordance with the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) guidelines to address three research questions oriented to cigarette smoking, in order to: (1) Investigate the behavioral and physiological manifestations of cigarette smoking targeted by wearable sensors for smoking detection; (2) explore sensor modalities employed for detecting these manifestations; (3) evaluate underlying signal processing and pattern recognition methodologies and key performance metrics. The review identified five specific smoking manifestations targeted by sensors. The results suggested that no system reached 100% accuracy in the detection or evaluation of smoking-related features. Also, the testing of these sensors was mostly limited to laboratory settings. For a realistic evaluation of accuracy metrics, wearable devices require thorough testing under free-living conditions.

Keywords: ECG; IMU; RIP; cigarette smoking; respiration; signal processing; smoke exposure; wearable sensor.

Figure 1

Flow diagram depicting the systematic review strategy.

Figure 2

An illustration of a smoking-specific respiration pattern (horizontal axis: Time in milliseconds, vertical axis: Breath volume).

Figure 3

The instrumented lighters: (a) UbiLighter v1; (b) UbiLighter v2; (c) UbiLighter v3; (d) the Personal Automatic Cigarette Tracker (PACT) lighter (image source: [60,61]).

Figure 4

The concept of proximity sensor: Closeness of hand to mouth, i.e., the closeness of module 1 to module 2.

Figure 5

An instance of inertial sensor implementation on the dominant hand of smoking for detecting smoking hand gestures.

Figure 6

(a) RIP breathing sensor on chest; (b) sensor components.

Figure 7

Acoustic sensor attached to the suprasternal notch to detect smoke related breathing.

Figure 8

Egocentric camera attached to the eye-glass temple to captured details of smoking event.