The use of information technologies in the first level of attention in health represents advances not only in improving medical diagnosis but also in patient care [1]. These advances allow the data exchange between medical institutes or health professionals. Often, there is not a practical objective in the technologies used, and its final use is confusing. Thus, inclusion in the clinical field is carried out at different speeds and with slightly homogeneous technological models [1]. Finally, inefficient implementations that affect adherence to the use of the devices are obtained. In this paper is introduced a model for assistive technologies developing. This document is formed by three essential parts: model, validation (tests stage) and results and discussion. The first, the criteria for assistive technologies development criteria are defined with an interdisciplinary approach. Then, a use-case-in which the model is applied-is shown. It is proposed that the use of a simulator to test two proposed components. With health professionals, the relationship between scientific criterion and expected results in a clinical environment are verified. The application of the metodology and use of the simulator leads to the detection of improvements in the requirements analysis. The improvements imply the reduction of development time of a technology that assists the functional reach test.