Telemonitoring Techniques for Lung Volume Measurement: Accuracy, Artifacts and Effort

Abstract

Telemonitoring becomes more important in pulmonary research. It can be used to decrease the pressure on the health care system, to lower the costs of health care and to increase quality of life of patients. Previous studies show contradictory results regarding the effectiveness of telemonitoring. According to multiple researchers, inefficiency can be a result of poor study design, low data quality and usability issues. To counteract these issues, this review proves for an in-depth explanation of four (potential) telemonitoring systems in terms of work principle, accuracy, disturbing factors and usability. The evaluated systems are portable spirometry/breath-by-breath analyzers, respiratory inductance and magnetic plethysmography and electrical impedance tomography. These insights can be used to select the optimal technique for a specific purpose in future studies.

Keywords: Lung volumes; Telemonitoring; accuracy; artifacts; effort.

Figure 1

Lung volumes. Inspiratory capacity (IC), functional residual capacity (FRC), inspiratory reserve volume (IRV), tidal volume (TV), expiratory reserve volume (ERV), residual volume (RV), vital capacity (VC), total lung capacity (TLC).

Figure 2

Representation of techniques. (A) hand-hold spirometer, (B) schematic overview of RIP system (C) RIP incorporated in smart shirt (Hexoskin) (28), (D) portable BbB-analyser system, (E) portable BbB-analyser system worn by a patient (written informed consent was obtained from the individual for the publication of this figure), (F) schematic overview of RMP system, (G) schematic overview of EIT system.

Figure 3

Bias and limits of agreement distribution in liters for tidal volume (TV) (, , , , , , , , , , –90), end-expiratory lung volume (EELV) (36, 37, 87, 91), forced expiratory volume in 1s (FEV₁) (, , , , , –94) and forced vital capacity (FVC) (69, 74, 92, 93) per telemonitoring technique. Spiro; spirometry (including BbB-analyzers) in blue, RIP; respiratory inductance plethysmography in orange, RMP; respiratory magnetic plethysmography in gray, and EIT; electrical impedance tomography in yellow.