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Chow, et al.
finite element models (FEMs) are commonly used to the patient. During the study, she was ordered to wear a
enhance the design of orthoses or prostheses through customized pressure sleeve with a silicone insert at all
numerical simulation. For instance, Zolfagharian et al. times except when she had to bathe or apply the silicone
[44]
demonstrated the use of FE analysis (FEA) in the design gel, which was done twice a day. The study was approved
of a patient-specific 3D-printed splint for mallet finger by the Human Subjects Ethics Sub-committee of The
injury to ensure that the mechanical properties of the Hong Kong Polytechnic University (Reference Number:
design meet the requirements but production consumes HSEARS20171214001) and Joint Chinese University
the least amount of material. These customized products of Hong Kong-New Territories East Cluster Clinical
first incorporated the geometric shape of the body part Research Ethics Committee (CREC Ref No: 2018.467).
obtained through 3D scanning to cater to each patient
based on his/her needs. After that, FEA can be adopted 2.2. Evaluation of current treatment
to modify the design to enhance the performance of the Current treatment with silicone sheets is problematic in
product based on the material properties of the 3D printed that the silicone sheet debonds from the skin. To evaluate
materials without any further trial and error fittings, thus the adhesion between the silicone sheet and skin under
minimizing the volume of material waste during the different conditions, ASTM D5169 Standard Test Method
design process. for Shear Strength (Dynamic Method) of Hook and Loop
In this study, we propose a novel framework to Touch Fasteners was referenced and the Instron 5566
manufacture a bespoke garment for HSs using a workflow universal mechanical test frame was used. Pigskin was
of 3D scanning, 3D printing, FEA, and computer-aided used to represent human skin, which was cleaned using
design and manufacturing software. The 3D printed a nonionic detergent and then padded dry with paper
silicone insert which conforms to the profile of the HS is towel. The size of the specimens is 2.54 × 7.62 cm. The
attached to a pressure garment to eliminate the problem of temperature of the wrist is approximately 34 – 36°C
its displacement. Hence, scar treating gel can be applied depending on the activity and the environment [45,46] .
with a silicone insert, thus helping patients toward a Testing was therefore carried out in a temperature-
quicker recovery. The integration of pressure, silicone controlled chamber and the specimens were kept at a
sheet, and silicone gel therapies will surely open new paths temperature of 35°C to simulate normal skin temperature.
of development in HS treatment. A female participant In the experiment, two different commercial silicone
was invited for a clinical study to observe the feasibility sheets, CICA-CARE and Mepiform , were evaluated
®
of the suggested therapy. Our proposed framework is also under four different skin conditions, which are normal dry
valuable for different types of customized products in the skin and skin separately coated with three different types
clinical field. of scar care gels, which are SILBIONE BLEND 4001
®
®
2. Materials and methods (Elkem), Hiruscar , and Contractubex . The suggested
dosage and mode of application are discussed as follows.
2.1. Details of clinical case 2.3. Design framework
A 51-year-old female patient with a body mass index of
21.5 kg/m who has undergone surgical operation on her Figure 1 illustrates the overall design framework that
2
right wrist was recruited for the study. The patient has given involves the combination of three different types of
her written informed consent to publish the pictures and therapies. The details will be discussed in the following
her personal data. In December 2018, the patient suffered sections.
a radial bone fracture near her right wrist. During surgery, (1) Three-dimensional scanning and modeling
metal screws were applied to stabilize the radial during
the healing process. About 1 month after surgery, an HS The first and second steps of the design framework are to
with a raised and dark red appearance developed on her conduct 3D scanning and modeling (Figures 1A and B).
hand. Afterward, she underwent silicone sheet therapy to The geometry of the wrist and shape of the HS of the
increase scar maturation and improve the appearance of patient was obtained using a structured light handheld 3D
the HS. However, the silicone sheet frequently debonded. scanner (Artec Eva, Luxembourg). The scanner captures
For example, the silicone sheet would debond when she the texture and color of the scanned object which is
sweated (wet skin), came into contact with other surfaces convenient during the silicone insert modeling process
due to the friction (excessive friction between the silicone to differentiate between the healthy skin and HS. The
sheet with the desk when typing on a keyboard, or with scanned data were registered using Artec Studio 13 and
the bed sheets while she slept at night). To address these then imported into a 3D model processing software (3ds
problems, a bespoke HS treatment that combines pressure, Max, Autodesk). To create a model that corresponds with
silicone gel, and silicone sheet therapies was designed for the scar, a box object with a similar length and width

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