Comparison of Strain-Gage and Fiber-Optic Goniometry for Measuring Knee Kinematics During Activities of Daily Living and Exercise

There is increasing interest in wearable sensor technology as a tool for rehabilitation applications in community or home environments. Recent studies have focused on evaluating inertial based sensing (accelerometers, gyroscopes, etc.) that provide only indirect measures of joint motion. Measurement of joint kinematics using flexible goniometry is more direct, and still popular in laboratory environments, but has received little attention as a potential tool for wearable systems. The aim of this study was to compare two goniometric devices: a traditional strain-gauge flexible goniometer, and a fiberoptic flexible goniometer, for measuring dynamic knee flexion/extension angles during activity of daily living: chair rise, and gait; and exercise: deep knee bends, against joint angles computed from a “gold standard” Vicon motion tracking system. Six young adults were recruited to perform the above activities in the lab while wearing a goniometer on each knee, and reflective markers for motion tracking. Kinematic data were collected simultaneously from the goniometers (one on each leg) and the motion tracking system (both legs). The results indicate that both goniometers were within 2–5 degrees of the Vicon angles for gait and chair rise. For some deep knee bend trials, disagreement with Vicon angles exceeded ten degrees for both devices. We conclude that both goniometers can record ADL knee movement faithfully and accurately, but should be carefully considered when high (>120 deg) knee flexion angles are required.

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Validation of three-dimensional total knee replacement kinematics measurement using single-plane fluoroscopy

International Journal Sustainable Construction & Design ◽

10.21825/scad.v7i1.3634 ◽

2016 ◽

Vol 7 (1) ◽

pp. 14

Author(s):

R. Daems ◽

Jan Victor ◽

Patrick De Baets ◽

S. Van Onsem ◽

Matthias Verstraete

Keyword(s):

Motion Tracking ◽

Sagittal Plane ◽

Tracking System ◽

Knee Kinematics ◽

In Vivo Evaluation ◽

Single Plane ◽

Validation Experiment ◽

Flexion Extension ◽

Total Knee

Instability of the knee after total knee arthroplasty (TKA) is today the number one reason for aseptic revision surgery. In vivo evaluation of knee kinematics using single-plane fluoroscopy has become an important method to investigate knee stability and compare dierent implant designs. A validation experiment was performed to assess the accuracy of this method. A total knee implant was installed on sawbones and a flexion extension movement was performed with the sagittal plane parallel to the detector panel of the fluoroscope. Simultaneously, the sawbones were tracked using a conventional motion tracking system and rigidly attached markers. That measurement can be seen as a golden standard and is therefore believed to represent the real positions. The results indicate that knee rotations can be measured with an accuracy of approximately 0.6 and sagittal plane translations can be measured with an accuracy of approximately 0.4 mm. These results prove that the method is sufficiently accurate for clinical use.

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The role of negative intra-articular pressure in the maintenance of shoulder joint stability in dogs

Veterinary and Comparative Orthopaedics and Traumatology ◽

10.1055/s-0038-1632992 ◽

2006 ◽

Vol 19 (03) ◽

pp. 157-161 ◽

Cited By ~ 3

Author(s):

R. M. McLaughlin ◽

S. H. Elder ◽

C. R. Boyle ◽

E. B. Silverman ◽

B. K. Sidaway

Keyword(s):

Shoulder Joint ◽

Motion Tracking ◽

Tracking System ◽

Weight Bearing ◽

Joint Capsule ◽

Neutral Position ◽

Joint Stability ◽

Flexion Extension ◽

Before And After ◽

Motion Tracking System

SummaryThe objective of this study was to evaluate the effect of negative intra-articular pressure on shoulder joint stability in canine cadavers. Cadaver forelimbs from 12 mature dogs were used. The forelimbs were placed in a testing frame and axially preloaded with 4 kg of weight. Shoulder joint stability was tested in flexion, extension, and neutral position before and after venting of the joint capsule. Humeral translation relative to the glenoid was induced by applying a 3 kg load in three different directions (cranial, lateral, and medial) and quantitatively measured by use of an electromagnetic motion tracking system. Peak translational data were compared in each joint position before and after venting of the joint capsule. After venting the shoulder joint capsule, a significant increase in translation was observed in the cranial direction with the joint in neutral position and in the medial direction with the joint in extension. The horizontal translations measured after venting of the joint capsule were likely not clinically relevant. Negative intra-articular pressure is not a major contributor to shoulder stability in dogs during weight-bearing.

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Desktop lighting for comfortable use of a computer screen

Work ◽

10.3233/wor-208018 ◽

2021 ◽

Vol 68 (s1) ◽

pp. S209-S221

Author(s):

Lu Han ◽

Hechen Zhang ◽

Zhongxia Xiang ◽

Jinze Shang ◽

Shabila Anjani ◽

...

Keyword(s):

High Intensity ◽

Motion Tracking ◽

Tracking System ◽

Computer User ◽

Eye Tracker ◽

Computer Screen ◽

Task Load ◽

Trunk Movements ◽

Motion Tracking System ◽

Nasa Task Load Index

BACKGROUND: The contrast between a bright computer screen and a dark ambient environment may influence comfort of the users, especially on their eyes. OBJECTIVE: The objective of this research is to identify the optimal desktop lighting for the comfortable use of the computer screen in a dark environment. METHODS: An experiment was designed where seven illumination setups were introduced for the users to perform their leisure tasks on a computer screen. Fifteen healthy subjects participated in the experiments. During each session, durations of the eye blinks, fixations and saccades of the user were recorded by an eye tracker. His/her neck and trunk movements were recorded by a motion tracking system as well. The comfort/discomfort questionnaire, localized postural discomfort questionnaire, NASA task load index and computer user questionnaire were used to record the overall comfort/discomfort, the local perceived physical discomfort, the cognitive workload, and general/eye health problems, respectively. RESULTS: Subjective and objective measurement results indicated that users felt more comfortable with high intensity warm lights using a computer screen. We also identified that the eye fixation durations, as well as the scores of two questions in the computer user questionnaire, have significant negative correlations with comfort. On the other side, the durations of blinks and the scores of three questions in the computer user questionnaire, were significantly correlated with discomfort. CONCLUSION: The warm (3000K) and high intensity (1500 lux) light reduced the visual and cognitive fatigue of the user and therefore improve the comfort of the user during the use of a computer screen.

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IoT-Based Motion Tracking System for Orthopedic Patients and Athletes

2020 Medical Technologies Congress (TIPTEKNO) ◽

10.1109/tiptekno50054.2020.9299223 ◽

2020 ◽

Author(s):

Gizem COBAN ◽

Faruk AKTAS

Keyword(s):

Motion Tracking ◽

Tracking System ◽

Motion Tracking System ◽

Orthopedic Patients

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Multi-sensor three-dimensional Monte Carlo localization for long-term aerial robot navigation

International Journal of Advanced Robotic Systems ◽

10.1177/1729881417732757 ◽

2017 ◽

Vol 14 (5) ◽

pp. 172988141773275 ◽

Cited By ~ 2

Author(s):

Francisco J Perez-Grau ◽

Fernando Caballero ◽

Antidio Viguria ◽

Anibal Ollero

Keyword(s):

Monte Carlo ◽

Motion Tracking ◽

Robot Navigation ◽

Tracking System ◽

Three Dimensional ◽

Measurement Unit ◽

Indoor Environments ◽

Localization Algorithm ◽

Monte Carlo Localization ◽

Motion Tracking System

This article presents an enhanced version of the Monte Carlo localization algorithm, commonly used for robot navigation in indoor environments, which is suitable for aerial robots moving in a three-dimentional environment and makes use of a combination of measurements from an Red,Green,Blue-Depth (RGB-D) sensor, distances to several radio-tags placed in the environment, and an inertial measurement unit. The approach is demonstrated with an unmanned aerial vehicle flying for 10 min indoors and validated with a very precise motion tracking system. The approach has been implemented using the robot operating system framework and works smoothly on a regular i7 computer, leaving plenty of computational capacity for other navigation tasks such as motion planning or control.

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Low-cost respiratory motion tracking system

10.1117/12.772922 ◽

2008 ◽

Author(s):

Mohammed Goryawala ◽

Misael Del Valle ◽

Jiali Wang ◽

James Byrne ◽

Juan Franquiz ◽

...

Keyword(s):

Motion Tracking ◽

Respiratory Motion ◽

Tracking System ◽

Low Cost ◽

Motion Tracking System

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Evaluation of the SteamVR Motion Tracking System with a Custom-Made Tracker

Applied Sciences ◽

10.3390/app11146390 ◽

2021 ◽

Vol 11 (14) ◽

pp. 6390

Author(s):

Marcin Maciejewski

Keyword(s):

Motion Tracking ◽

Tracking System ◽

Training System ◽

Random Errors ◽

Operational Conditions ◽

Custom Made ◽

Systematic And Random Errors ◽

Position And Orientation ◽

Motion Tracking System ◽

System Operating

The paper presents the research of the SteamVR tracker developed for a man-portable air-defence training system. The tests were carried out in laboratory conditions, with the tracker placed on the launcher model along with elements ensuring the faithful reproduction of operational conditions. During the measurements, the static tracker was moved and rotated in a working area. The range of translations and rotations corresponded to the typical requirements of a shooting simulator application. The results containing the registered position and orientation values were plotted on 3D charts which showed the tracker’s operation. Further analyses determined the values of the systematic and random errors for measurements of the SteamVR system operating with a custom-made tracker. The obtained results with random errors of 0.15 mm and 0.008° for position and orientation, respectively, proved the high precision of the measurements.

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