Alleviating Dyspnea With Non-Invasive Neuromodulation

The goal of this feasibility sham-controlled randomized trial is to assess the feasibility of studying non-invasive neuromodulation techniques, specifically transcutaneous vagal nerve stimulation (tVNS) and transcutaneous electrical nerve stimulation (TENS) of the trigeminal nerve to alleviate dyspnea in patients with chronic pulmonary disease. The main question it aims to answer is: Despite challenges in dyspnea generation and measurement, could non-invasive neuromodulation be reliably studied in chronic obstructive pulmonary disease (COPD) with severe dyspnea? Researchers will compare tVNS and trigeminal TENS to a sham (where the device is applied, but without stimulation) in order to see if non-invasive neuromodulation could relieve dyspnea. At the time of rehabilitation pre-assessment, participants routinely undergo a baseline maximal Cardiopulmonary Exercise Testing (CPET) on ergocycle to measure VO2max with repetitive assessments of the Borg scale and continuous monitoring of vital signs (oxygen saturation, heart rate, blood pressure, respiratory rate) throughout the test. Spirometry and symptom questionnaires (CAT score) are also routinely measured. In two dedicated study visits conducted 2 weeks apart from each other, n=8 participants will perform a submaximal constant workrate (CRW) at 80% workload of the VO2 max, either with cervical tVNS (n=4) or trigeminal TENS (n=4). In a cross-over design, both patient groups will undergo sham and active treatment of the neuromodulation technique in a randomly assigned number.