Continuous remote monitoring of COPD patients-justification and explanation of the requirements and a survey of the available technologies

Abstract

Remote patient monitoring should reduce mortality rates, improve care, and reduce costs. We present an overview of the available technologies for the remote monitoring of chronic obstructive pulmonary disease (COPD) patients, together with the most important medical information regarding COPD in a language that is adapted for engineers. Our aim is to bridge the gap between the technical and medical worlds and to facilitate and motivate future research in the field. We also present a justification, motivation, and explanation of how to monitor the most important parameters for COPD patients, together with pointers for the challenges that remain. Additionally, we propose and justify the importance of electrocardiograms (ECGs) and the arterial carbon dioxide partial pressure (PaCO₂) as two crucial physiological parameters that have not been used so far to any great extent in the monitoring of COPD patients. We cover four possibilities for the remote monitoring of COPD patients: continuous monitoring during normal daily activities for the prediction and early detection of exacerbations and life-threatening events, monitoring during the home treatment of mild exacerbations, monitoring oxygen therapy applications, and monitoring exercise. We also present and discuss the current approaches to decision support at remote locations and list the normal and pathological values/ranges for all the relevant physiological parameters. The paper concludes with our insights into the future developments and remaining challenges for improvements to continuous remote monitoring systems. Graphical abstract ᅟ.

Keywords: COPD; Chronic obstructive pulmonary disease; Decision support in healthcare; Patch ECG; Remote patient monitoring; Telehealth; Telehealthcare; Telemedicine; Transcutaneous measurement; eHealth.

Graphical abstract

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Fig. 1

Hypoxic pulmonary vasoconstriction and its inhibition by oxygen therapy. a Normal alveolar ventilation and perfusion. b Reduced ventilation in the darker alveolus (thus, the local pO₂ also drops) causes reduced perfusion. c Oxygen therapy increases pO₂ in all the alveoli, including the dark one, and inhibits hypoxic pulmonary vasoconstriction

Fig. 2

A prototype of a patch ECG monitor developed at the Jožef Stefan Institute, Ljubljana Slovenia [81, 82], with two self-adhesive disposable electrodes, a lithium coin battery, micro-processor, BT4 radio, and printed circuit board antenna (up). Savvy sensor, the final product (down)

Fig. 3

Representative spirograms (expired volume–time curves) for healthy subjects (FEV1/FEV ~ 4.6/5.8 = 0.8) and subjects with COPD (FEV1/FEV ~ 1.7/3.4 = 0.5)

Fig. 4

General architecture of remote monitoring systems

Fig. 5

Interval of an ECG (red) measured with a patch ECG monitor, and respiration intervals (black) measured by a thermistor near the front of the nose. The amplitude of the measured ECG signal varies with respiration. All nine respiration intervals are identified (blue circles). The presented results come from a study reported in [99]

Fig. 6

Overview of existing decision support systems. a Sensors used (Other: video/audio (five systems), physical activity (four systems), ECG (two systems), lung and heart sounds (one system), glucometer (one system)). b Patient action needed for data acquisition or automatic data acquisition. c Algorithms used. Total number of participant used in the studies is 1866, whereas the average duration of the studies was 6.4 months