Electromagnetic Respiratory Effort Harvester: Human Testing and Metabolic Cost Analysis

Abstract

Remote health monitoring is increasingly recognized as a valuable tool in chronic disease management. Continuous respiratory monitoring could be a powerful tool in managing chronic diseases, however it is infrequently performed because of obtrusiveness and inconvenience of the existing methods. The movements of the chest wall and abdominal area during normal breathing can be monitored and harvested to enable self-powered wearable biosensors for continuous remote monitoring. This paper presents human testing results of a light-weight (30 g), wearable respiratory effort energy harvesting sensor. The harvester output voltage, power, and its metabolic burden, are measured on twenty subjects in two resting and exercise conditions each lasting 5 min. The system includes two off-the-shelf miniature electromagnetic generators harvesting and sensing thoracic and abdominal movements. Modules can be placed in series to increase the output voltage for rectification purposes. Electromagnetic respiratory effort harvester/sensor system can produce up to 1.4 V, 6.44 mW, and harvests 30.4 mJ during a 5-min exercise stage. A statistical paired t-test analysis of the calculated EE confirmed there is no significant change ( P > 0.05 ) in the metabolic rate of subjects wearing the electromagnetic harvester and biosensor.

Microwave and wearable technologies for 5G

“…Energy expenditures were recorded for subjects with and without harvesting sensors, during sitting, standing, fast walking, and slow walking. A statistical analysis confirmed there is no significant change in the metabolic rate of subjects wearing the harvesting sensor [18]. A plot showing a comparison of energy expenditure with and without the wearable sensor is shown in Figure 9, confirming this finding.…”

“…Another source of human kinetic energy is the movement of the chest/abdominal wall during respiration [17]- [18]. Movement of the chest wall during normal breathing can be monitored [19] and harvested to facilitate self-powered wearable respiratory sensors for continuous remote monitoring.…”

“…Electric current can be generated by rotating a conducting coil inside a magnetic field, which can be achieved by physically turning the armature of a motor. A Pololu 50:1 DC brushed motor was chosen based on size, cost, and easy modification into a belt [18]. The expansion of the torso during inspiration turns the armature.…”

State feedback control for human inspiratory system

“…Shahhaidar et al [21] presented results of human testing of a weight 30 g with energy sensor of respiratory effort. The output voltage of harvester, metabolic burden, and power are tested on 20 patients in conditions of exercise and resting each lasting 5 minutes.…”

Energy Harvesting from Upper-Limb Pulling Motions for Miniaturized Human-Powered Generators

“…The human body has also been considered as an excellent platform for applying such technologies, since the body contains a lot of ambient energy [ 2 ]. There have been many attempts to supply power to mobile devices in real-time using the energy generated by the human body [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ]. They include shoe-mounted generators [ 3 , 4 , 5 ], knee-mounted generators [ 6 ], energy harvesting on a backpack [ 7 , 8 ] and harvesting energy from breathing [ 9 , 10 ].…”