Aim: We designed a vest to apply transcutaneous electrical stimulation to elicit vibration to the chest wall, as a method to help mobilize secretions.A pilot study (Phase 1 of the entire research protocol ELECTROVEST) was designed to evaluate safety, possible secondary effects and grade of tolerability, in a group of healthy people.

Methods: Four sessions of thoracic vibrations with the prototype vest were applied to a gruoup of 10 healthy subjects, with at least 24 hours between them. Prior and after the study sessions, we measured the estimated glomerulus filtration rate (eGFR) and forced expiratory volume in the first second (FEV1) as the primary variables, and others of pulmonary function, exercise performance (6min walk test) and respiratory muscle strength, as the secondary ones. Regarding comfort, the visual analog scale was applied to describe discomfort.

Results: No statistically significant difference was found in most of the variables: the median eGFR was 112 vs 107 (p: 0.067), FEV1 96% vs 94% (p: 0.221), before and after therapy. The rest of the secondary variables did not show significant decreases with respect to baseline. 90% of the subjects described values of 2 or less in the comfort scale. No serious adverse effects occurred.

Conclusions: The application of thoracic vibrations through electrostimulation therapy (ELECTROVEST), is safe and offers an adequate tolerability and comfort. Although there were no serious adverse effects, in the following phases of the study, creatine kinase should be monitored more frequently.

Funded by Consejería Salud, Junta de Andalucía. PIP-0218-2021