A 4C/ZW3D Solution

Problem Definition: Deformational Plagiocephaly

It's important for babies to sleep on their back asthis reduces the risk of sudden infant death syndrome (SIDS). This means babies sleep more in thesame position. This is good to prevent SIDS, but when children are sleeping all the time in the same position, there is a possibility that Plagiocephalywill develop. Plagiocephaly means "flattening of some areas of the head", meaning a skull-deformation. More children are developing DP-issues. Posterior Plagiocephaly and Brachycephaly (Rear of Head Flatness) can also be present at birth.


It is very important to act early in the life of the infant, otherwise this deformation will become permanent. In order to correct the problem, a Cranial Orthosis Helmet, defined by a Paediatric Craniofacial Physician, will progressively correct the babies head and bring it back to its natural shape. To achieve this, the infant’s head needs to be measured and used to create a custom-shaped helmet. The baby will wear the helmet for most of the day. The progression of the reshaping is monitored through the duration of the treatment and corrective actions are applied if/as necessary.

Measurements with a 3D Scanner

Measurements of the baby’s skull used to be done manually. This would be done with plaster - a technique potentially traumatizing for a young child - or other manual measurement methods, at the expense of inaccuracy. Clearly ‘manual’ methods have limitations.

A far more accurate and baby-friendly solution is 3D scanning. The baby is placed in a rotating chair. The 3D scanner acquires the 3D data of the skull as a Point Cloud. This is a simple, easy to use, fast and accurate method. Being a noninvasive process is very important for the parents confidence in the whole procedure.

Leverage of the 3D data

1. Analytic Study/Reporting
The 3D data from the scan can firstly be used for analytic study. The amount of deformation can be calculated, by using an established method of measuring the data. Technical reports can be printed for use by the Physician and simplified reports for the parents. During the period of treatment, further scans can be made and compared to study progress

2. Designing the helmet
From the 3D data, the most optimal shape of the helmet can be defined. The DP Designer system proposes this optimal shape, which is reviewed by a Technician/ Physicianand fine tuned where necessary.

3. Producing the helmet
When the helmet shape is ready for production, the software automatically calculates the toolpath for a milling process. This can be done with standard tools available in the shop. 3D Printing is also a possibility.

The software
DP Designer was developed in close collaboration with experts in this field and reporting is done in accordance with the methods of Professor van Vlimmeren1. DP
Designer’s engine is ZW3D, presenting a task specific user interface to accommodate the Orthopaedic Technician’s requirements and skills. Automation isincorporated as much as possible since the Users are not CAD/CAM experts.

The scan information is loaded into DP Designer andwithin minutes a report is created with all the relevant data. This data is calculated fully automatically, and the technician has the possibility to choose exactly which data slice is relevant to examine within the dataset. Multiple scans can be imported and compared, and again reports produced, all within a single ZW3D file.
The final shape of the Helmet is defined with DP Designer by an Orthopaedic Technician. DP Designer presents a simple step-by-step process requiring minimal input to produce a 3D model of the helmet shape as a mould for subsequentvacuum forming. Deformations of the skull are smoothed-out via an interpolation process to create curves that are the basis of the 3D model. Since every child is different, this part of the process can be weighted by the Technician as required. DP also automates the production of a toolpath file ready for the mould machining and interactively produces edge trimming curve data for the final shape

1 a.o. described in: Plagiocephalometry: a non-invasive method to quantify asymmetry of the skull; A reliability study; European Journal of Pediatrics 165: 149-157 ,2006