1. Smart Joint Methods and Optimal Sensor Placement
Omid Karimpour
Author to whom correspondence should be addressed; E-Mail: okarimpour@gmail.com; Tel.: +1-647-447-5915

2. 1.introduction
2. Gait Analysis
3.Optimal placement of
accelerometers
2

3. Introduction
• most striking feature of human movement
• Different kind of sensors and their location
• kinematics and kinetics method

4. Gait Analysis
• Not only gait kinematics but also gait kinetics
• sports, rehabilitation and so on.
• hip, knee, and ankle joints
• estimate 3D ground reaction forces (GRFs)

5. • walking is a periodic movement • eight different gait phases

6. using both accelerators and gyroscopes
Gait Kinematic
• force = mass × acceleration
• increase accuracy
• initial sensing system
• measure angular rate and the angle of various joints
• using Kalman and Gaussian filter to evaluate the hip angle

7. Gait Kinetics
• Force and Moments
• force plate between foot
and ground
• five mounted sensor
• Center of Pressure
measurement

8. EMG and Muscle Force
• small electric current
• connecting to skin
• muscle force calculation
• strike to strike timing

9. Optimal Placement of
accelerators
• everyday activities
• six wireless sensor in chest, foot, hip and so on
• Hip is the best single location
• using on chest, wrist and hip = 92% accuracy

10. works summary by Reference

11. summary of the time take in
different activities

12. • energy value for each axis
• axis correlation

13. most accurate activities
• Machine learning algorithms
• NB,NN,SVM and C4.5 DT
• SVM has significant accuracy
• Real time and work reliable on noisy data sets
• F-Measure=2 x(precision x recall)/(precision + recall
SVM = support vector machine
F-measurement = performance index to evaluate the SVM's ability

14. hip represent best total body
movement

15. number of sensor that is
sufficient to use
• average correctly
classified instance
• two location has the best
performance