DEVELOPMENT OF NORMALIZED NAVICULAR HEIGHT MEASUREMENT SYSTEM BASED ON FOOT LATERAL IMAGE

• Main Author: ALMANDA YULFIANO - NIM 13213028 , GERRY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27489
• Institution: Institut Teknologi Bandung

<p align="justify">Generally, navicular height (NHt) is measured from foot lateral x-ray image of the patient. The physician marks the most medial point of navicular tuberosity then measures its distance to the supporting surface by using standard ruler. The normalized navicular height (NNHt) is the ratio on NHt to the foot length. This work proposed a similar system by using foot lateral image from regular camera. The patient’s foot (the most medial of navicular tuberosity point) marked with red circle which then tracked by an algorithm and the distance between that marker and supporting surface was measured and normalized by dividing it to subject’s foot length. Red color detection algorithm was used to detect the red circle mark and foot length was measured by finding the distance of two extreme point (left and right) in foot contour from foot lateral image. Our designed system was implemented with raspberry pi camera (with fisheye lens) and raspberry pi 3. Fisheye lens widen the field of view of pi camera up to 180 degrees and enabled the system to shoot the whole foot lateral area in one image. Image taken by fisheye lens was not linear, so pixel calibration was needed. Two sets of calibration data was created which represent horizontal and vertical position of the image. Polynomial regression from these data generated the equation to convert position from pixel to cm unit. Result showed that NNHt measurement system has average error of 4,89%. <p align="justify">