method, uses minimal spatial apparatus and
equipment, and is environment-friendly because it
does not release harmful by-products.
Statistical observation of the signals shows
significant VAG consistency of the normal knee
both in frequency and amplitude in most of the
tests performed. However, the OA knee shows
major inconsistency in both variables. It is also
worth noting that the high amplitude pulses on the
OA VAG indicate the most damaged areas where
the major friction between two bones is applied.
Conclusion
Figure 5: OsteoKnee™
Case Studies
The VAG signals were captured from both normal
and OA knees for the differences to be compared
and analysed . Figure 6 shows the first half of the
captured data of a normal knee and Figure 7 the
first half of a knee with severe OA.
The X, Y and Z illustrations in Figures 6
and 7 represent the vibration motion in 3D space
as shown in Figure 8. While the knee is in motion
the patella will vibrate and move in three of these
directions and the sensor will monitor and capture
these motions for recoding storage. The values
of the maximum and minimum amplitude of the
signal at each specific time will represent where in
3D space the object is placed.
Figure 6: Normal knee VAG
The use of VAG with highly accurate MEMS sensors
shows promising results in the detection of OA.
This vibrograph method possesses great promise
to diagnose other complex structural parts of the
body non-invasively in the future. This method has
major potential to pioneer technology in the field
of biomedical engineering as well as human health
care. The nature of microcontrollers and ICs also
opens up possibilities for more portable and low
cost devices that would not have been possible in
the past.
Figure 8: X, Y and Z motions on
the sensor
Figure 7: OA knee VAG
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