MOTION CAPTURE

Question 1

what is motion capture

Answer 1

process of recording movement of people / objects

Question 2

need for motion capture (2)

Answer 2

1. assessment of health status

2. rehabilitation process

Question 3

motion capture conventional practices (4)

Answer 3

1. low tech mainly observational
2. subjective evaluations
3. poor evaluation criterea
4. bad long term monitoring

Question 4

MOCAP applications (4)

Answer 4

1. gait analysis
2. rehabilitation & monitoring
3. patient motion capabilities & habits
4. ergonomic analysis

Question 5

biomedical model shows (5)

Answer 5

skeleton, joints, positions

velocities, acceleration (linear/angular)

Question 6

motion capture classified as (2)

Answer 6

1. invasive & internal

2. noninvasive & external

Question 7

example of invasive internal (2)

Answer 7

1. x-ray

2. fluoroscopy imaging

Question 8

4 types of motion capture

Answer 8

1. mechanic
2. magnetic
3. optical
4. inertial

Question 9

2 types of optical

Answer 9

1. markers

2. markerless

Question 10

MECHANICAL
what measures movements
what is exoskeleton composed of (2)

what does deformation of exoskeleton do

Answer 10

deformable exoskeleton
segments connected by metal or pastic geniometers
potentiometers on joins
transformed into electrical signals

Question 11

MAGNETIC
what detects
what is detected

Answer 11

magnetomeres / electromagenetic coils

orientation or movement in magentic field

Question 12

OPTICAL
what type of camera
what do cameras do (2)

what is optical-markers
what is optical-markerless

Answer 12

infrared
1. track light source or reflection
2. identify profiles from video frames
markers placed in remarkable points of the body
dedicated tool recognizes the body

Question 13

2 types of markers

Answer 13

1. passive

2. active

Question 14

what are passive markers

Answer 14

retroreflective markers

Question 15

what are active markers (2)

Answer 15

LEDs, markers

Question 16

main factors of optical markers (4)

Answer 16

1. number of cameras
2. camera resolution & frame rate
3. light condition
4. contrast: marker vs. background

Question 17

problem w/ optical marker

Answer 17

occlusion by person/obstacles

Question 18

optical marker technology (3)

Answer 18

1. VICON (passive)
2. QUALYSIS (both)
3. OPTITRACK (both)

Question 19

OPTICAL-MARKERLESS

3 benefits optical markerless

Answer 19

1. low cost
2. simple
3. portable

Question 20

optical markerless mechanism

Answer 20

human body silhouette identified, then identify body parts

Question 21

optical markerless equipment (2)

Answer 21

RGB camera / RGB depth camera

Question 22

INERTIAL

what detects

Answer 22

1. accelometers

2. gyroscopes

Question 23

inertial units

Answer 23

inertial measurement units

Question 24

inertial advantages (2)

Answer 24

1. portable

2. capture tight spaces

Question 25

inertial cons (2)

Answer 25

1. low position accuracy | 2. position drift

Question 26

1. OPTICAL MARKER (both active & passive) | pros (2)

Answer 26

1. high precision | 2. free marker positioning

Question 27

1. OPTICAL MARKER (both active & passive). | Cons (3)

Answer 27

1. high cost 2. long setup time 3. need dedicated lab

Question 28

OPTICAL MARKERLESS - RGB | pros (2)

Answer 28

1. low cost | 2. easy calibration

Question 29

OPTICAL MARKERLESS - RGB | cons (3)

Answer 29

1. low precision 2. need up to 6 cameras 3. influence of environment

Question 30

OPTICAL MARKERLESS-RGB-D | pros (3)

Answer 30

1. low cost 2. good precision 3. easy calibration

Question 31

OPTICAL MARKERLESS-RGB-D | Cons (1)

Answer 31

1. interference among sensors

Question 32

INERTIAL-3D ACCEL | pros (2)

Answer 32

1. low cost | 2. sensibility

Question 33

INERTIAL-3D ACCEL | cons 2

Answer 33

1. loose positioning | 2. long setup time

Question 34

SOFTWARE tasks for motion capture processing

Answer 34

1. joints identification 2. skeleton generation & motion 3. motion data 4. medical indexes

Question 35

motion capture flowchart steps:

Answer 35

1. camera calibration 2. capture tight spaces 3. 2D marker identification 4. subject calibration 5. 3D marker reconstruction 6. cleanup 7. skeletal motion

Question 36

example of independent mocap software

Answer 36

iPi motion capture (sony playstation)