Design and development of a novel double-chamber syringe concept for venous catheterization.

This paper presents the optimization process for the development of an innovative double chamber syringe. Several aspects are involved such as design, functionality, fluid-structure interaction and friction between solids. To assist in the development of this medical device, a numerical based methodology was developed and validated in order to predict the syringe´s functionality, as well as its production by injection molding. The mechanical and flow behavior, during the filling and administration of medicine and washing solutions, were numerically modelled using the commercial software ABAQUS and FLUENT, respectively. The injection molding process was analyzed using the software MOLDFLOW. The aim was to evaluate the feasibility of the proposed concept in terms of mechanical design, fluid flow and production process behavior. By highlighting critical design issues in this way, it was possible to identify promising geometric changes and, consequently, optimize iteratively the syringe's design, until all the defined requirements are fulfilled. This iterative process based on numerical simulations proved to be a powerful tool for product development that generated fast and accurate results without the need to produce multiple prototypes.

Usability Assessment of an Innovative Device in Infusion Therapy: A Mix-Method Approach Study.

Background: Flushing a venous access device is an important procedure to maintain their patency and prevent malfunctioning and complications. An innovative double-chamber syringe was developed, allowing for the assessment of catheter patency, drug delivery and final flush. This study aims to assess the usability of this new device, considering three development stages (concept, semi-functional prototype, functional prototype). Methods: An iterative methodology based on a mix-method design (qualitative and quantitative) enabled the assessment of the devices' usability by their primary end-users. A usability questionnaire was developed and applied, along with focus groups and individual interviews to nurses. Results: The usability questionnaire integrated 42 items focused on four dimensions (usefulness; ease of use; ease of learning; satisfaction and intention to use). The initial psychometric findings indicate a good internal consistency and the conceptual relevance of the items. The scores seem to be sensitive to the usability evaluation of the medical devices in different stages of product development (with lower values on functional prototype evaluation), and related to nurses' perceptions about functional and ergonomic characteristics. Conclusions: Quantitative and qualitative data provided a comprehensive overview of the double-chamber syringes' usability from the nurses' point of view, informing us of features that must be addressed.

Development of an innovative double-chamber syringe for intravenous therapeutics and flushing: Nurses' involvement through a human-centred approach.

BACKGROUND: In nursing practice, flushing the catheters pre and post-drug administration is considered an important clinical procedure to prevent complications, and requires the use of several syringes to comply with international standards of care. We envisioned an innovative double-chamber syringe that enables the filling and administration of both solutions. Following current international recommendations, the development of new medical devices should integrate Health Technology Assessment. The Human-centred design is usually used for that assessment purposes, as a method that actively include end-users in the devices development process. METHOD: Application of the Human-Centred Design through the involvement of nurses in the initial stages of the device development in order to accomplish the initial stages of Technology Readiness Level. A multi-method approach was used, including literature/guidelines review, focus groups with end-users and expert panels. RESULTS: The involvement of nurses enabled the definition of user requirements and contexts of use, as well as the evaluation of design solutions and prototypes in order to accomplish with usability and ergonomic features of the medical device. CONCLUSIONS: Significant contributions were made regarding the final design solution of this innovative double-chamber syringe.

Study Protocol for Two-Steps Parallel Randomized Controlled Trial: Pre-Clinical Usability Tests for a New Double-Chamber Syringe.

A new double-chamber syringe (DUO Syringe) was developed for intravenous drug administration and catheter flushing. This study presents a protocol for pre-clinical usability tests to validate the golden prototype of this new device, performed in a high-fidelity simulation lab by nurses. A two-steps parallel randomized controlled trial with two arms was designed (with standard syringes currently used in clinical practice and with the DUO Syringe). After randomization, eligible and consented participants will be requested to perform, individually, intravenous drug administration and flushing, following the arm that has been allocated. The procedure will be video-recorded for posterior analyses. After the completion of the tasks, nurses will be asked to answer a demographic survey, as well as an interview about their qualitative assessment of the device. A final focus group with all participants will also be conducted. Primary outcomes will concern the DUO Syringe's effectiveness, efficiency, and safety, while secondary outcomes will focus on nurses' satisfaction and intention of use. The pre-clinical protocol was defined according to the legal requirements and ISO norms and was reviewed and approved by the Ethics Committee of the Health Sciences Research Unit: Nursing of the Nursing School of Coimbra.