Biomedical Engineering Reference
In-Depth Information
Fig. 1
Separable steps for production and development of the Fraunhofer ivD-platform
product (Fig.
1
). This workflow is divided into vertical and horizontal lines. While
the horizontal line represents the production of the cartridge, the various vertical
lines represent steps of development or preproduction steps.
Starting from a biomarker, the first essential step is the development of an assay
which determines the specific biomarker. After having established this in a normal
laboratory workflow, for example as an Enzyme-Linked Immunosorbent Assay
(ELISA), the assay has to be transferred into the LoC design. Hence, the basis
body has to be treated to match the needs of the specific assay. Further develop-
mental steps are then reagent production and sensor manufacturing combined with
spotting of the capture molecules on the sensor and blocking for the reduction of
un-specifically bound analyte molecules (all shown as vertical lines in relation to
the horizontal production line). Finally, before obtaining a marketable product the
detector and the software also have to be adapted to the specific assay to provide
results in an appropriate design for the specific application.
Because of the open and modular form of the systems the workflow has many
degrees of freedom. Depending on the application and specifically depending on
the targeted analytes (i.e., proteins, DNA, or small molecules) different techniques
for surface treatment, different reagents, different analytes, or also a different
sensor have to be chosen. In particular, the different degrees of freedom includes
sample preparation, clean up and amplification, labeling (e.g., fluorescence or
redox-cycling), synthesis of probe and binding molecules, spotting, printing,
immobilization, hybridization, incubation, microfluidics, detection, data collec-
tion, and data analysis. In this regard many steps can be modified to match in all
cases the requirements of the assay enabling a detection of the analyte in the
medically relevant range.
2.2 Cartridge
The core of the ivD-platform is a cartridge the size of a credit card exhibiting an
outer diameter of 85 9 45 mm and a height of 3.8 mm. The cartridge mainly
