SCAN TO KNIT
A Smart Tex0le Pla3orm for Personalised Prosthe0c Tex0les
In Sweden, approximately 3000 people are amputated every year; about 90 % of which cases are amputees of the lower extremi?es and about 10 % of the upper limbs. When a person becomes a limb amputee, he or she is faced with staggering emo?onal and financial lifestyle changes. The
amputee requires a prosthe?c device(s) and services, which become a life-‐ long event. The simple truth is that if the prosthesis is uncomfortable, the person is not going to wear it. Surveys from Europe indicate that overall
sa?sfac?on with prosthe?cs among amputees is ranging between 70-‐75% .
Contact: Li Guo, Swedish School of Tex?les, University of Borås, li.guo@hb.se
ACKNOWLEDGMENT
We would like to acknowledge The Swedish Knowledge founda?on KK-‐s?Welsen for funding.
SCAN TO KNIT
Objec0ves
Improving pressure-‐, humidity-‐ and thermal-‐related comfort in a cost-‐ effec?ve manner that requires fewer skills is a challenge to the
prosthesis industry.
The human skin is a sophis?cated organ that is vulnerable to sustained and concentrated exposure of any kind.
CASE 2: Smart tex0les for home-‐based Phantom Limb
Pain (PLP) treatment
CASE 1: Personalized prosthe0c socks for improved
socket-‐stump interface comfort
CASE 3: Smart socks for controlling powered prosthe0cs
How can smart tex.les and new tex.le produc.on techniques be applied in prosthe.cs?
A slightly poor fit in the prosthe?c socket or even a poorly placed seam of a prosthesis sock can result in localised pain, bruising, redness, blisters, or skin
ulcera?ons in the residual limb. In prac?ce, true comfort is extraordinarily difficult to achieve and maintain.
Using computerised kni[ng
methods, SCAN TO KNIT allows for complex design based on, e.g.:
Intarsia technique can be used to
create pa^erns with mul?ple yarns.
Double-‐jersey techniques can create
two layers of fabrics and knit simultaneously.
Interlock kni[ng can knit two
unconnected fabrics to formulate a tubular structure.
The Vanise technique (plated
kni[ng), can handle two different yarns concurrently with the same needle and overlap, which allows
that one type of yarn can be covered (plated) by another (s?ff) yarn
resul?ng in a reinforced kni^ed fabric.
The objec?ve of the project is to inves?gate tex?le methods that contribute the missing links to develop personalised
smart tex?le solu?ons for prosthe?c limb users with a special emphasis on improving user comfort.
1. Stump volumetric data acquisi0on:
The biological data is collected at
clinical sites using e.g. Laser scanning, 3D scanning, Magne?c Resonance
Imaging (MRI) or Computer Tomography (CT).
2. Create a 3D geometric model of the residual limb: The 3D model, indicated
by a colour-‐coding system, is generated based on the measurement data and saved in “the cloud”. A mathema?cal descrip?on will be developed based on the measurement data.
3. Mathema0c transfer: convert the
mathema?cal descrip?on of the
residual limb to the kni[ng pa^ern.
4. Prototyping: The kni[ng technicians
at the tex?le manufacturing site will inspect the kni[ng pa^ern, modify it if needed and conduct the produc?on.
Background
The combina?on of smart tex?les and the new tex?le produc?on technology, i.e. Scan to Knit allow an
individualised sock/sleeve with integrated myoelectric electrodes posi?oned according to the evalua?on of remaining muscle ?ssue performed at the clinic to be produced for each amputee. Such an individualised sock/ sleeve opens up for home-‐based treatment of PLP that can be administered by the amputee without any
assistant from a prosthe?st or therapist.
Tex?le electrodes, have proven to be an a^rac?ve
alternate method of recording Electromyographic (EMG) signals. This solu?on enable the design and produc?on of a func?onal tex?le interface between the amputated limb and the socket of the prosthe?c device to improve
wearability and comfort at the same ?me facilita?ng myo-‐ electric control of powered prosthesis.
