Feasibility of Home-based tES for Older Adults at Risk of Falling

In this project, the investigators propose to demonstrate the feasibility of remotely-monitored, caregiver (or spouse)-administered, home-based tES (transcranial electrical stimulation) intervention to improve mobility in ambulatory older adults with recent falls. This is a four-phase feasibility study in older, ambulatory adult participants at risk of falling due to a loss of balance (participant faller, PF) together with a willing and able participant administrator (PA) that is available during weekdays to administer tES to the PF. Phase 1 is focused on the development and refinement of our training materials for home-based tDCS (transcranial direct current stimulation) for PF/PA pairs. The objectives of this phase: 1. Identify areas of confusion and challenges for older adults. 2. Refine our training materials to accompany the home-based tDCS system. In Phase 2, the investigators will complete a pilot trial in 12 PF/PA pairs to assess the feasibility of deploying home-based tES in larger clinical trials, and to prepare for the development and implementation of such trials. The objectives of this phase: 1. Determine the mean/range number of visits needed for in-person training. 2. Compliance and retention with the study protocol. 3. Safety/side effects of home-based tES, as compared to previously established laboratory-based tES data. The investigators hypothesize that adult PAs are able to successfully administer home-based tES to PFs. The investigators also expect that PF/PA pairs will exhibit excellent adherence to the intervention and that the prevalence and severity of reported tDCS side-effects will be similar to that observed in previous laboratory-based studies. In Phase 3, the investigators will complete a pilot trial in up to 18 PF/PA pairs; i.e., those who have previously successfully completed either Phase 1 or Phase 2. The study objectives/aims for Phase 3 are: 1. Further explore compliance and retention with the study protocol over a longer time period 2. Identify safety/side effects of home-based tES over a longer time-period as compared to previously established laboratory-based tDCS interventions. In Phase 3, the investigators hypothesize that adult PA's who have previously demonstrated the ability to successfully administer tES at home, will retain competence and compliance with administration over a longer period, up to 1 year. In Phase 4, we will complete a pilot trial in up to 18 PF/PA teams; those who have previously successfully completed Phase 3. The study objective/aims for Phase 4 will be to: 1. Identify Safety, effectiveness and adherence to home-based tES over longer period of time as compared to previously established laboratory-based tES interventions. 2. Further explore the proof of Concept for the home-based tES interventions In Phase 4 we hypothesize that adult PA's who have previously demonstrated the ability to successfully administer tES at home, will adhere with the study protocol over a longer period of time, up to 3 years.