1. DESIGN AND DEVELOPMENT
OF A NOVEL FORCE PLATE
AYMAN SIDDIQUE [ID: 7669311]
MSC MED PROJECT SUPERVISOR: DR. GLEN COOPER

2. INTRODUCTION: DIABETES AND DIABETES MELLITUS
Diabetes Mellitus (Type 2- Diabetes) is a medical condition when the human body is unable to produce the
necessary insulin required, or develops insulin-resistance, i.e. cannot respond to its effects.
In 2013, the IDF had
estimated that the
global expenditure
attributed to the overall
treatment of diabetes
to be about USD 548
billion and USD 678
million in 2013 and
2035, respectively.

3. PATHWAY TO DIABETIC FOOT ULCERATION
“The lifetime risk of a
person with diabetes
developing a foot ulcer
could be as high as 25%
and it is believed that every
30 seconds a lower limb is
lost somewhere in the world
as a consequence of
diabetes.” –Boulton
As of 2010, 15-20 % of
patients who suffer from
foot ulcers would be in
need of an amputation,
with 85% of these foot
amputations following
diabetic foot ulceration.

4. ANATOMY OF THE HUMAN FOOT
• 7 short tarsal bones incorporate the heel and back of the instep.
• 5 metatarsal bones constitute the structure for the ball of the foot. Each metatarsal is associated with one
of the toes.
• The toe structure comprises of 14 phalanges and small bones
• Tarsal and metatarsal (MTH) bones provide the arch structure of the foot
• Bands of ligaments inter-connect and constrict the bones
• A thick layer of fatty tissue lies underneath the sole of the foot, in order to absorb the pressure and
shock during various stages of gait
A human foot consists of 26 bones,
which further constitute of 33
joints, 19 muscles, 107 ligaments
and several tendons.

5. BIOMECHANICS OF PLANTAR FOOT ULCERATION
The skin acts as the medium through which internal forces are conveyed to its surroundings as well as the
environmental external forces that act on the skin itself and its corresponding subcutaneous tissue.
The number of force repetitions
required to cause tissue injury
decreases as the force (pressure)
increases, and vice versa. This is
known as a pressure time
integral, and many researchers
have used this relationship to
determine the risk of
diabetic foot ulceration.
“Mechanical fatigue is defined as the failure of a structure or biological tissue at a
submaximal level to maintain integrity because of repeated bouts of loading.”
Ulceration is instigated due to the combination of reduced sensation (intrinsic factor) and high plantar
pressure (extrinsic mechanical factor) when the foot undergoes uncharacteristic mechanical loading.

6. PLANTAR SHEAR FORCE MEASUREMENT: A REVIEW
Optical Method (Mackey and Davis, 2006)
Strain Gauge Method (Cheng et al.,2010)
• Force sensor based on strain gauge techniques and
the shear-web principle
• The sensor was able to measure the AP and ML
shear forces and the normal force at the plantar
surface, by utilising the embedded strain gauge
rosettes
• Each strain gauge rosette provided three sensor
output channels
The evaluation of plantar stress distribution is crucial in order to identify diabetic feet that are prone to ulceration.
• Optics-based force sensor which determined pressure and
shear patterns on the plantar surface
• The system is able to measure three-dimensional (3-D) stress
tensors at all points of contact with the sole of the foot.
• The system can be calibrated automatically by simply being
activated, and measures optical phase retardance while
collecting zero-load data

7. ULTRA-SOUND TISSUE IMAGING: A REVIEW
• Soft Tissue Response Imaging Device (STRIDE)
• Simultaneously subjugated plantar soft tissue to
vertical compression and recorded the
corresponding mechanical response.
• Foot scanner with an embedded tissue ultrasound palpitation
(indentation) system (TUPS) in order to evaluate plantar soft tissue
properties under the loading of different body-weights.
• The scanner allowed real-time tracking of foot movements.
Evaluation of the mechanical properties of plantar soft tissues in conjunction with plantar shear
measurement could facilitate monitoring of diabetes development and subsequent prevention of diabetic
foot ulceration.
TUPS: (Zheng et al, 2010)
STRIDE: (Parker et al.,2015)

8. PROPOSED DESIGN: AIMS, OBJECTIVES AND SPECIFICATIONS
AIMS:
To design and develop a force plate that can simultaneously measure the
tri-axial shear forces of a specific plantar region, and determine the
mechanical characteristics of its corresponding soft tissue.
OBJECTIVES:
• To design concepts for the force sensor which incorporates strain
gauge techniques and commercial ultrasound devices
• To compare the concepts and progress one of them to the
embodiment design phase
• To validate the embodiment design through use of FEA and
numerical calculations and hence determine a final design for the
force sensor
• To commission and test the final design before proceeding with
manufacturing of force sensor

9. PROJECT SCHEDULE

10. PROPOSED DESIGN: DEVELOPMENT, EVALUATION AND FURTHER WORK
Construction and
analysis of FEA
foot model using
MRI images of foot
Integration
into matrix
array
Determination of
sensitivity, hysteresis and
non-linearity
FEA
validation of
force sensor
design

11. THANK YOU FOR LISTENING
ANY QUESTIONS?