# Design Methodology for Soft Wearable Devices--The MOSAR Case
## 2 Design Methodology  
The design of soft devices must guarantee a safe operation since these systems could be in contact with patient's skin, tissues, organs or surgical tools [30]. To couple a SWD to human limbs to operate intuitively as a whole system, with easy donn-doff, without obstructing natural motions and nor causing deterioration of the patient is still a challenge.  
To face these challenges, MFV strategies consider technology to assess the physical condition of the patient. For instance, brain activity is mostly evaluated by electroencephalography and magnetic resonance imaging tests [31] while muscle impairment and joints ROM assessment use EMG (Electromyography) tests [32].  
The field of soft wearable devices requires new methodologies that empathize with patients' needs to analyze their physical condition and not only to cope with people demands. The methodology proposed in this paper combines MFV phases with BTM principles in order to create a patient-centered design whose respective solution is scaled, depending on patient's limitations, to reach a general procedure.  
This new methodology proposes the conception and manufacturing of soft wearable devices based on integral assessment about patient health (medical technology and experts' feedback). Basically, it seeks to unify medical, therapeutic and engineering guidelines for the continuous improvement of:  
* Research. It starts with a custom analysis about patient's clinical condition considering specialists' criteria and available medical technology. From these assessments, valuable information is obtained to define constraints and operation conditions prior to SWD design.
* Development. It encompasses SWD design to obtain a virtual model, its manufacture and control. This paper proposes reverse engineering as a CAD tool to model and obtain a morphological reference of the target limb for the design concept of SWD.
* Innovation. It relies on the reverser engineering approach to accelerate the manufacturing and implementation of SWD systems as available products.  
The interaction between research, development and innovation is illustrated in Figure 1, where the next 8 aspects are highlighted.  
1. A continuous improvement action is illustrated by arrows in a counter-clock wise direction.
2. Innovation and development share information and actions in both senses.
3. The clinical state of a patient is assessed by a neurologist, therapist and EMG tests.
4. Development is based on the reverse engineering approach.
5. The target limb characterization involves ROM testing, casting molds and 3D scanning techniques for its 3D digitalization.
6. During the development, detail engineering is applied for changes on the modeling and manufacturing phases.
7. Experimental validation is carried out, firstly, on a dummy limb and later on the patient.
8. A continues review of the states of the art and the technique (A&T) are considered on the process.  
Figure 1: Structure of the design methodology for soft wearable devices (SWDs).  
To achieve the objective of this methodology, it is divided into two stages (A and B) and four phases (1 to 4). The methodology is integrated by 29 steps distributed as it is shown in Table 1 and detailed in Figure 2. The description of these phases and steps is provided in the following paragraphs.