Seoul National University Movement Research Lab. Seoul National University Bundang Hospital Jiwon Jeong

1/8 Motivation (1/2) Find the best surgical plan and minimization of unexpected side effects Focus on the surgery which cause transformation of bone geometry Care about the complex side effects of single-stage multi-level surgery Movement Research Lab. SNU Personal Data (X-Ray) Automatic 3D Reconstruction Lower limb bone (Femur, Tibia) 3D mesh model Manual Simulation By person Using simulator Automatic Simulation By simulator Need policy Perform Surgery Find Best Solution Variables (position, angle, wedge, etc.)

2/8 Motivation (2/2) What is an important criterion when developing the surgical plan? Clinical measurements (neck-shaft angle, femoral version, shaft bowing etc.) Lower limb alignment (mechanical axis, anatomical axis, etc.) Movement Research Lab. SNU [Clinical measurements] [Lower limb alignment]

3/8 Approach Full Process 3D reconstruction of lower limb using X-ray images (2 biplanar X-ray images) Find the feature points in lower limb using 3D geometry model Calculate the parameters which are related with lower limb posture Find the best surgical plan (below is an example of FVDO) Input : patient’s current posture (feature points and parameters pair) predefined ideal posture (parameters) Output : wedge angle, cutting position, rotation angle and expected posture Processing : minimization of error between patient’s posture and ideal posture Movement Research Lab. SNU

4/8 Process #1 3D Reconstruction of lower limb using X-ray images Input : 2 biplanar X-ray images Output : 3D geometry model of femur and tibia Development approach Femur : already done (be sure to check it is working accurately to abnormal bone) Tibia : development approach is as same as femur reconstruction Movement Research Lab. SNU [Process of femur reconstruction]

5/8 Process #2 & #3 Find the feature points of lower limb using 3D geometry model Using vertex level processing, find the feature points Calculate the parameters which are related with lower limb posture Using the feature points, calculate the axes, planes, and parameters Movement Research Lab. SNU [Lower limb feature points & axes example] Parameters Neck-shaft angle Femoral version Hip-knee-ankle angle Condylar-tibia angle Mechanical axis deviation [Parameters example]

6/8 Process #4 (1/2) Movement Research Lab. SNU [FVDO]

7/8 Process #4 (2/2) Movement Research Lab. SNU

8/8 Action Plan Set the feature points and parameters Define important parameters for surgical plan or lower limb posture Define axes, planes, and points for calculation of parameters Formulation Tibia reconstruction Make a training set for tibia reconstruction Check the accuracy of femur reconstruction solution for an abnormal bone Develop a tibia reconstruction Movement Research Lab. SNU

9/8 Crouch Posture 논문 동영상 주요 스토리라인 Movement Research Lab. SNU 구분주요 내용 Introduction Crouch posture 특성을 보여주는 다양한 케이스 소개 Question & Hypothesis 소개 Experiment 소개 Crouch posture 장비 및 착용 영상 (crouch 각도 표시 포함 ) Crouch 실험 전반에 대한 소개 ( 미는 부분, 밀린 거리 측정 부분 설명 ) Crouch 실험 카테고리 소개 ( 속도 / 보폭, 방향, posture, crouch) Experiment 결과 및 분석 방향 소개 실험 결과 영상 ( 촬영 영상 및 이에 대응하는 motion viewer 영상 ) 분석 시 제외한 조건에 대한 설명 (2 걸음 이상 밀린 케이스 panic mode) 통계 분석 결과 Crouch 각도에 따른 통계 분석 결과 Stride 에 따른 통계 분석 결과 Speed 에 따른 통계 분석 결과 Push timing 에 따른 통계 분석 결과 통계 분석 결과 Summary 추가 진행 사항 Further exploration (gait simulation 적용 내용 )