**5. Standards for ideal on-site diagnostic microfluidic devices**

Microfluidic devices that would like to be tested and sold as on-site diagnostic devices, must first adhere to a standardized set of criteria set out by the WHO. The WHO published a list of criteria that states that on-site diagnostic devices must be "affordable, sensitive, user-friendly, rapid and robust, equipment-free and deliverable to end-users" [2]. These criteria are the 6 basic standards that prospective on-site diagnostic devices should strive to achieve, otherwise known as ASSURED. The ASSURED criteria allow researchers and healthcare professionals to assess the effectiveness of prospective on-site diagnostic devices [2]. The six criteria can be further divided into two main categories for evaluation, the technical and the practical criteria. The technical criteria include: "sensitivity", "rapid and robust", as well as "equipment-free". While the practical criteria include: "affordable", "user-friendly" and "deliverable to end users". While some criteria are not necessarily related to one another, they are nevertheless all equally important in designing an idealized on-site microfluidic device. However, the ASSURED criteria are not easy to be simultaneously and effectively implemented. Therefore, to improve the overall potential of a microfluidic device as an effective on-site diagnostic tool, several other more measurable criteria must also be addressed; as seen in **Figure 7**.

Effective diagnostic microfluidic devices that manage to address the ASSURED criteria, as best as possible, may still struggle to measure how they are addressing these criteria [2]. **Figure 7** summarizes a list of seven more measurable criteria that simplify and quantify the characteristics that best represent an ideal on-site microfluidic device used for diagnostic purposes. These "seven pillars" of integrated microfluidic device design will aid in providing developers with quantifiable metrics to better evaluate their device's efficacy and on-site diagnostic potential.
