According to the World Health Organization, by 2050, the number of persons over 65 years old will increase by 73% in the industrialized countries and by 207% worldwide.1 This segment of population is particularly prone to suffer a cerebrovascular accident or stroke, since the relative incidence of stroke doubles every decade after age 55. Stroke survivors immediately experience hemiparesis, resulting in impairment of extremities associated with diminished health-related quality of life.2 Rehabilitation can help hemiparetic patients to learn new ways of using and moving their weak arms and legs. It is also possible with immediate therapy that people who suffer from hemiparesis may eventually regain movement. However, reductions in healthcare reimbursement place constant demands on rehabilitation specialists to reduce the cost of care and improve productivity.3 Service providers have responded by shortening the length of patient hospitalization.4,5 Additionally, early home supported discharge of subacute stroke patients has been proved to have a significant impact on motor recovery after stroke although it requires some level of innovation of methods and tools for service delivery to really become a sustainable solution for the healthcare system.6,7 All these reasons support the necessity of in-home rehabilitation systems as the one proposed in this work.
Socially, chronic stroke patients can highly benefit from innovative approaches based on home rehabilitation therapy.8 Technological and scientifically, only a few commercial systems are currently available for in-home use (e.g. HandMentor™,9 ReJoyce,10 and ArmeoBoom from Hocoma), and their performances are not comparable to in-person therapies.11 Key challenges not addressed properly for home systems include features such as affordability, autonomy, and high performance. Only if all requirements are satisfied, it will be possible to encourage national health systems, insurance companies, and patients to apply such platforms.
This work is part of an ongoing project called HomeRehab that will develop a new tele-rehabilitation robotic system for delivering therapy to stroke patients at home. Instead, Technologies has a robotic system called RoboTherapist 2D (Figure 1) developed to provide rehabilitation to patients who suffer from stroke and/or other neurological disorders.12 Currently, the system, as the majority of commercial devices, is only designed to be used in hospitals and medical centers in collaboration with nurses and medical staff.13
HomeRehab aims to modify and adapt the system so it can be used at home by patients easily and supporting the premise of tele-rehabilitation.14 This article describes in detail the mechanical design of the new HomeRehab system that adapts the RoboTherapist 2D for in-home use by making it smaller, lighter, and cheaper, but maintaining its high performance. Additionally, the system includes a third degree-of-freedom (DOF) plus a novel low-cost force sensor that were not considered for the original platform, but they are very interesting features for a complete in-home solution. Another key feature of the whole system is that it integrates patient monitoring techniques using wearable devices to monitor the physiological state of the patient and modify exercises based on that information.
The following section briefly summarizes the main requirements considered to develop a successful device, and afterward in section “Mechanical design,” the mechanical design of the new system is described in detail. Section “Robot controller” presents the controller of the robot as well as the adaptive controller implemented for the rehabilitation therapies. Section “Usability pilot study” carries out a validation phase by conducting several tests and surveys to compare the usability of RoboTherapist 2D with HomeRehab, and last section gathers main conclusions. […]