The assessment of skin viscoelastic data related to post-burn scarring: Mathematica in clinical use and biomedical research II

Iveta ((Bryjová)^(a,b,c))
 
in collaboration with Stanislav ((Hledík)^a), Hana ((Klosová)^d) & Jiří ((Štětinský)^d)

aInstitute of Physics, Faculty of Phil. & Science, Silesian University in Opava, Czech Republic
bDept. of Cybernetics and Biomedical Engineering, Technical Univ. of Ostrava, Czech Republic
cDept. of Epidemiology and Public Health, Faculty of Medicine, Univ. of Ostrava, Czech Republic
dBurn Center, University Hospital Ostrava, Czech Republic

Iveta apologizes for sending me as a substitute ...

... for the following reason (with her permission):

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Burn wounds medical care

Initial period

Up to 48 hrs; 12–24 hrs: microcirculation most compromised. Not covered here.

Medium-term (healing) period

48 hrs: repair processes create high perfusion that can meet metabolic requirements

Time ~ days up to 2-3 weeks

Blood perfusion assessment:

Discussed in the previous talk: Improving laser Doppler aided diagnostics of burn injuries

Long-term period

Time ~ weeks up to months/years

The healing of deep dermal or full thickness burns frequently develops into widespread and mutilating scars, giving rise the risk of subsequent scar hypertrophy

The assessment of postburn scarring and scar therapy response based on scales routinely used in clinical evaluation (VSS, POSAS, VAS, MSS) is inherently subjective and prone to bias

A non-invasive suction method based on the measurement of scar viscoelastic properties termed cutometry has been found reliable for scar assessment

Skin viscoelastic parameters assessment

The principle: mechanical response of the skin exposed to an underpressure of precisely defined time dependence.

The response is affected by viscoelestic properties of the skin which can be drawn from the measured strain-vs-stress curves, and customarily expressed in terms of viscoelastic parameters like gross-elasticity, net-elasticity, biological elasticity and several others.

A typical shape of strain-vs-stress curve and the measuring probe in action are depicted below right

Flawed curves may occur now and then. Below left: Example of cutometric curve corrupted presumably by air leakage around the probe aperture. Below right: Example of cutometric curve corrupted presumably by inadvertent penetration of hair remnants into the probe aperture.

How can Mathematica be helpful?

The dedicated software supplied together with the device omits the abundance of information contained in the strain-vs-stress curves.

At this point we utilized the capabilities of Mathematica to make up the methods by more advanced ones that are well fitted to reveal subtleties buried in the curves.

Package CutometerMPA580Q being developed

Mathematica creates the catalog of all curves to pick the eligible ones:

The following sample figures are taken from the publication Klosová, H. et al. Objective evaluation of the effect of autologous platelet concentrate on post-operative scarring in deep burns. Burns [online]. 2013, DOI: 10.1016/j.burns.2013.01.020 whose data were exclusively processed using Mathematica. Further method refinement is currently under development and will be presented in full version provided the contribution is accepted.

Mathematica implementation

Go to Cutometry notebook |->

(Target notebooks are not available with this presentation but can be requested at hlediks@gmail.com)

Conclusion

CutometerMPA580Q package

More flexible than original dedicated software

Allows implementation better methods of signal processing

Allows results to be seemlessly passed to statistical computations

Improvement of diagnostics and hypertrophy scarring prevention

Things to do

More exact methods for cutometric curves to be implemented

More precise location of inflections

Connection to database

Automatic detection of flawed curves

Mathematica extended package CutometerMPA580X development

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