# Design and Modelling a Graduated Dispenser for Metabolic Diseases--Phenylketonuria
## 3 Results  
The first step was to design this object (digital modeling) and then generate a file (usually in STL format) that contains all the technical geometrical information needed to export and convert this model into a list of instructions that the 3D printer can execute. According to these instructions, the process of creating the object began by using the 3D technology called FFT (Fused Filament Fabrication). This technology was also used to make this graduated dispenser and consists in modeling the object by melting a plastic filament and overlapping several layers of material. After the printing process was completed, the object was detached from the printing platform, the extra parts were removed, and the object was finished [11].  
The CAD design of the medicine tank was done in the Autodesk Inventor program and is presented in Figure 2. The device is composed of eight parts and two gaskets used to seal the powder in the dispenser. The component parts are:  
* transparent tube;
* tip;
* rod;
* two O-rings;
* two caps;
* a powder loading funnel in the dispenser body.  
The dispenser is graduated and can dose 12 g of substitute powder (12 g \(\times\) 0.6 = 7.2 g protein). The dispenser body, tip, rod, caps, and funnel were made on the 3D printer, and the clear tube and gaskets were purchased commercially.  
Obtaining the component parts through 3D printing (prototype) using the Prusa I3 MK3+ Printer (Figure 2), the working time related to the 3D printing of the dispenser was 12 h, the long time being due to printing with a support to achieve a quality as high as possible.  
This dispenser was designed for children (aged 6 months-1 year) and made for a protein substitute powder because it is easier to administer if they are in a different place than home. This substitute powder is stored in 500 g drums and this quantity is not always available to be transported. The substitute is administered only enteral, being in the form of powder that dissolves in water, syrups and fruit juices.  
In the following, we present the physical achievement of this dispenser in our CAD laboratory (Figure 3). The dimensions of the dispenser (Figure 4) are suitable for a bag and a food box and after use it can be washed easily.  
The dispenser dimensions (Figure 4) are suitable for a bag and a food box and after use it can be washed easily. The dispenser is pre-filled with protein substitute powder and can be transported this way because it has two caps that prevent the flow of the powder during transport, as can be seen in Figure 5.  
In phenylketonuria, L-amino acids from protein substitutes without phenylalanine do more than provide replacement proteins for growth and to maintain muscle mass, having a role in controlling blood phenylalanine and inhibiting its transport to the brain and absorption in the gut. Evidence suggests that a higher intake of formula increases satiety and thus favors better adherence to treatment and avoids transgressions [3; 12; 13; 14].  
Figure 2: The modelling and making process of the dispenser using the Prusa I3 MK35+ Printer: (**a**) stage 1 and (**b**) stage 2.  
At the time of dosing, the two caps are removed, the rod is fixed and attached to the tip of the dispenser, and the powder is pushed into the prepared container with liquid so  
Figure 4: The overall drawing of the dispenser.  
Figure 5: The alternative prepared for dosing (**a**) and transport (**b**).  
Figure 3: The physical achievement of this dispenser: (**a**) Prusa I3 MK3S+ Printer and (**b**) adjusting the printer parameters.  
that it can be mixed and ingested (Figure 5). After completely emptying the powder, this dispenser is washed and left to dry. It is a very convenient dosing variant in conditions where a scale is not available.