Introduction: Playing helps children to develop their mental, physical and social functions. On the other hand the term ‘discapacity’ means a limitation in the ability to play in some specific field. Taking these concepts into account, the percentage of suitable toys is insufficient, according to a study carried out by AIJU, titled ‘Playing, Toys and Discapacity’1.
This study has shown that only 69% of commercial toys are accessible for children with a hearing "discapacity", 27% with a visual discapacity and 18% for motor disability. They have special requirements and the toys need to be adapted for them to play with.
In other specific work of AIJU2, the authors established different recommendations, addressed to the toy manufacturers, for the design and developing of toy vehicles accessible to children with motor disabilities. All those recommendations are general rules for improving the safety and comfort of the children when playing, such as wider belts, higher back rests, bigger footrests, non-slip materials for the seats, push-buttons in different positions, etc. However, the customisation of parts of the vehicle for a unique child was not considered, since this option would be difficult and costly for the manufacturer.
The vehicle seat adaptation to a child’s body geometry is the best solution for most of the cases, as there is an important variety of health problems which lead to body deformation, paralysis or mobility handicap, that are different for each patient. The experience of parents who have disabled children confirm that the customisation of the toy seat could be a vast improvement for facilitating the use of the vehicle to the child, as the results of a survey carried out by AIJU during the project3 and included in the following section reflects.
For this reason, the aim of this work was the customisation of seats for battery powered toy vehicles (like cars and quads) for children with motor disability.
The benefit of personalization by adapting child seats for vehicles must be considered from two important aspects. The first one refers to the user's security. Let us consider a child affected by any kind of incapacity (legs, back) that prevents them from sitting in the same way a child without the disability would. In a customised seat, the child would be more tightly held within the vehicle and consequently would benefit from increased security. The second aspect, directly derived from increased safety/security, is the greater feelings of comfort that will make the child want to play longer. Finally, as the seat is personalised, the subsequent emotional involvement will allow the child to enjoy playing with the vehicle more and more. Paralelly, it creates peace of mind for the children’s tutors/parents.
Survey for parents with disabled children
With the objective of better knowing the difficulties that real people with motor disabilities have when playing and due to the social affectation the subject has, a survey was carried out in the Custom-Fit project. The answers were received through e-mail, the Custom-Fit website, CEAPAT, Government Organisation for Disabled People in Spain (ceapat.com) and Discapnet4 (discapnet.es).
The disease profile of the children is Cerebral Palsy (39%), psicomotor retardation (30%), encephalopathy (9%), Neuro-authonomic system disease (13%) and Others (9%). In the case of Other physical disabilities, Rett syndrome accounted for 67 %. The degree of severity of the diseases of the children in the study was made up of 74 % of children with a serious degree of disease and 26 % with a moderate degree.
The experience of parents who have disabled children confirm that the vehicle seat adaptation to the child’s body geometry could be the best solution for most of the cases. The results showed that, although 53% of the respondents had great difficulties in finding appropriate toys for their children and the same percentage had to modify them for their children’s playing use, a more elevated percentage (79 %) of them found it very interesting to customise the toy seat to their children’s disabilities.
When the affection grade is serious, those percentages are even higher, with 86 % considering it very interesting the customisation, 71% having difficulties in finding appropriate toys and 64% having to modify them for their children’s common playing.
Studying Initial Problems
The customisation process of the seats for battery powered toy vehicles carried out within Custom-Fit was specifically developed for a seven year old child whose left leg joints turn through 360° which hinders their attachment to any type of vehicle seat.
He had difficulties when using the original vehicle seat of the selected toy quad bike. Due to his disability the child slipped towards the left side, his left leg raised and he couldn’t put his foot on the rest foot, leading to very noticeable instability on the toy which was dangerous for him. The child could not play without tight surveillance.
The customization process begins with the geometrical data capture of the child by using a deformable inflatable cushion on the toy seat. After sitting on the cushion the child’s body shape and support points are firmly embedded onto by crating a vacuum inside and the cushion acquired the shape of the child.
By using a 3D laser scanner, several points clouds or meshes are generated from the cushion and transformed to a surface representation. The scan is translated into STL format, to be used in following design step.
The design of the external shape of the customised seat was based on the design of the original seat. The upper surface of the standard seat was modified in this case, to adapt it to the shapes according to the upper surface of the cushion, then, the seat was customised to the shapes, according the way that child was seated.
Through Delcam’s advanced 3D modelling system PowerSHAPE form Delcam, using the improved algorithms as a result of the Custom-Fit project, the design of the external shape of the customised seat was carried out by automatic combination of the files for both, the inflatable cushion with disabled child imprint and the original toy seat. A fusion was made between this surface representation and the CAD file of the car seat imported into the system. This produced a single combined digital file (cushion plus seat) representing a completely individualized seat, tailored to the special characteristics of the child.
With this information, a first prototype of the seat was manufactured by using conventional selective laser sintering with a polyamide material. However, such seats could be manufactured using other project developed technologies such as printing plastic powder (Power Plastic Printing, PPP) as this equipment is capable of printing any kind of thermoplastic, such as PP.
Once the customised seat was manufactured it was attached to the toy quad bike and was validated with the child with relevant results.
Validation Test and Results
A new photographic and video session was performed for the validation of the customised seat with the disabled child. With the customized seat the child fits perfectly onto the seat and is completely supported, reducing the possibility of falling as there was no slipping to either side.
Satisfaction was easily measurable in this case by simply observing the interrelation of the child with the toy.
With the customised seat, the child notably improves stability which implies that the quality of their playtime is vastly improved, and therefore the amount of time they spend playing will also increase as he is not afraid now. The child was very satisfied with the new situation and this emotional involvement will allow the child to enjoy playing and give his parents peace of mind as well.