Follow Up of a subject with Hemiparetic stroke using Interval - - PowerPoint PPT Presentation

Jorge Garza-Ulloa Electrical & Computer Engineering Doctoral Program The University of Texas at El Paso jgarzaulloa@miners.utep.edu uno@computecworld.com EE313 HUMAN LAB

“Follow Up of a subject with Hemiparetic stroke using Interval Computations ”

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Motivation

Real Case for the Follow-Up: We have a subject that had a Hemiparetic stroke. Information about the Stroke Patient  37 year old female  Hemiparetic Stroke  First visit: February 2010  Second visit: April 2010  Symptoms: Right hemiparetic  Treatment: Hydrotherapy “the best tools for balance evaluation in patients with stroke are still under debate.”

Volume 45 Number 8, 2008 Journal of Rehabilitation Research & Development

Can we do something to help?

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Outline

1.Introduction to: Interval Computations & Hemiparetic stroke

• 1. Treadmill Bortec to get data from subjects

2.Understanding the Human Gait Cycle. 3.Specification from the follow-up of the subject 4.Information of 2 visits of the subject 5.Defining Coefficients for follow-up

• 7. Conclusions

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 1.- Introduction to Hemiparetic stroke

Stroke is a sudden impairment in brain function. Usually, this is caused by the blockage, or the rupture, of a blood vessel Hemiparesis is muscle weakness on

• nly one side of the body. When

Hemiparesis happens as a result of a stroke, it commonly involves muscles in the face, arm, and leg. Hemiparesis is the most frequent neurological deficit after stroke .

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa

The treadmill analysis, it’s a split-belt instrumented treadmill (Bertec Corp.) measuring the Ground Reaction Forces (GRFs) of the subject.

How can we test a subject with Hemiparetic stroke?

Gait Cycle Ground Reaction Forces and Phases

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa

What are we measuring?

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 1.- Introduction to Interval Computations

Basic Math Operations: Example: Besides computational existence and uniqueness, interval arithmetic provides several other elementary but powerful tools. The most prominent, already mentioned, is bounding the ranges of functions.

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 1.- Introduction to Interval Computations

Application of Interval:

• Linear Systems_ Bounding the solution set of an interval linear system is as

fundamental in interval computations as in traditional point computations. An interval linear system is a system of the form AX = B;

• Nonlinear Systems/Optimization_ Because of interval arithmetic’s power to bound

ranges of functions, interval arithmetic has arguably been most successful in solution of nonlinear systems and global optimization. In global search algorithms for nonlinear systems of the form.

• Quadrature_ Adaptive quadrature is another area in which interval methods have

much to offer.

• Initial Value Problems_ provide enclosures for errors in the initial values, mathematical

truncation, and roundoff errors, so that, for each time point ti, intervals are produced that contain the actual solution .

• Boundary Value Problems and Partial Differential Equations _ in principle, be

converted to systems of ordinary differential equations or linear or nonlinear algebraic systems.

• Integral Equations and more

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 4.- Specification from the follow-up of the subject

First Visit 2-Feb-2010 She made the test a very slow Speed

• nly 2 cycles on 500 unit times

Second Visit 28-Apr-2010 She made the test medium slow Speed

• nly 3.5 cycles on 500 unit times

How can we compare both charts for Follow up?

Test: Ground Reaction Forces from the subject

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First Visit 2-Feb-2010 She made the test a very slow Speed only 2 cycles on 500 unit times

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Ranges - First Visit

Obtaining the ranges of Visit 1

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First Visit 2-Feb-2010 She made the test a very slow Speed only 2 cycles on 500 unit times

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Ranges of second Visit

Obtaining the ranges of Visit 2

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How can we compare the next charts for Follow up if they have different speed?

Average of Delta Max_Delta First Visit _Subject 0.032746 .212285 Second Visit_ Subject 0.0188 0.1027 Normal Health Subject 0.007027 0.039825

Healthy Subject has a Delta very small and the subject with stroke has a big delta

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Defining Coefficients for follow-up

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Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Defining Coefficients for follow-up GRC

We need to define a new term On Human Gait Cycle to adjust speed: GRC (Gait Relative Coefficient )= actual speed/Normal speed of the subject

Speed ( m/s ) GRC (Gait Relative Coefficient ) First Visit _Subject 0.25 0.2632 Second Visit_ Subject 0.5 0.5263 Normal Healthy Subject .95 1 The GRC must be applied on the Unit Time

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How can we differentiate when a subject is doing a good Gait cycle independent of speed? Answer: During gait cycle the normal is 60% stance 40% swing Based on this we need a Relative Coefficient Factor (CF):

RCF=ARC/ERC Where ERC is the Expected Rate Cycle and ARC the Actual Rate Cycle

RCF using X_Med (CF) RCF Coefficient ranges First Visit _Subject 3.0 [2.96,3.04] Second Visit_ Subject 2.0 [1.97,2.03] Normal Healthy Subject 1.0 [0.99 1.01]

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa Coefficient CF of Gait Cycle

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 6. Conclusions

On this case She is improving with the Rehabilitation

We have 3 parameters to measure the follow-up of a subject using his Gait Human Cycle: Relative Coefficient Factor (CF), GRC (Gait Relative Coefficient Max_Delta of Ranges

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RCF (Coefficient Factor

• f x_med

GRC (Gait Relative Coefficient ) Max_Delta Normal Healthy Subject 1.0 1.0 0.039825 Second Visit_ Subject 2.0 0.5263 0.1027 First Visit _Subject 3.0 0.2632 .212285

best

“It is not over, now that we obtain: The Get Relative Gait Cycle using data using Interval Computations theory We will have to prove it…”

Follow Up of a subject with Hemiparetic stroke using Interval Computations

Jorge Garza-Ulloa 7. Conclusions for the future

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