scholarly journals Curve Similarity Model for Real-Time Gait Phase Detection Based on Ground Contact Forces

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3235
Author(s):  
Huacheng Hu ◽  
Jianbin Zheng ◽  
Enqi Zhan ◽  
Lie Yu
Keyword(s):  
Real Time ◽  
Error Rate ◽  
Reference Method ◽  
Contact Forces ◽  
Ground Contact ◽  
Phase Detection ◽  
Gait Patterns ◽  
Similarity Model ◽  
Curve Similarity ◽  
Degree Of Similarity

This paper proposed a new novel method to adaptively detect gait patterns in real time through the ground contact forces (GCFs) measured by load cell. The curve similarity model (CSM) is used to identify the division of off-ground and on-ground statuses, and differentiate gait patterns based on the detection rules. Traditionally, published threshold-based methods detect gait patterns by means of setting a fixed threshold to divide the GCFs into on-ground and off-ground statuses. However, the threshold-based methods in the literature are neither an adaptive nor a real-time approach. In this paper, the curve is composed of a series of continuous or discrete ordered GCF data points, and the CSM is built offline to obtain a training template. Then, the testing curve is compared with the training template to figure out the degree of similarity. If the computed degree of similarity is less than a given threshold, they are considered to be similar, which would lead to the division of off-ground and on-ground statuses. Finally, gait patterns could be differentiated according to the status division based on the detection rules. In order to test the detection error rate of the proposed method, a method in the literature is introduced as the reference method to obtain comparative results. The experimental results indicated that the proposed method could be used for real-time gait pattern detection, detect the gait patterns adaptively, and obtain a low error rate compared with the reference method.

Adaptive method for real-time gait phase detection based on ground contact forces

2015 ◽  
Vol 41 (1) ◽  
pp. 269-275 ◽  
Author(s):  
Lie Yu ◽  
Jianbin Zheng ◽  
Yang Wang ◽  
Zhengge Song ◽  
Enqi Zhan
Keyword(s):  
Real Time ◽  
Adaptive Method ◽  
Contact Forces ◽  
Ground Contact ◽  
Phase Detection ◽  
Gait Phase

scholarly journals Self-Tuning Threshold Method for Real-Time Gait Phase Detection Based on Ground Contact Forces Using FSRs

Sensors ◽  
2018 ◽  
Vol 18 (2) ◽  
pp. 481 ◽  
Author(s):  
Jing Tang ◽  
Jianbin Zheng ◽  
Yang Wang ◽  
Lie Yu ◽  
Enqi Zhan ◽  
...  
Keyword(s):  
Real Time ◽  
Contact Forces ◽  
Ground Contact ◽  
Phase Detection ◽  
Threshold Method ◽  
Self Tuning ◽  
Gait Phase

scholarly journals Adjustable Method for Real-Time Gait Pattern Detection Based on Ground Reaction Forces Using Force Sensitive Resistors and Statistical Analysis of Constant False Alarm Rate

Sensors ◽  
2018 ◽  
Vol 18 (11) ◽  
pp. 3764 ◽  
Author(s):  
Fangli Yu ◽  
Jianbin Zheng ◽  
Lie Yu ◽  
Rui Zhang ◽  
Hailin He ◽  
...  
Keyword(s):  
False Alarm ◽  
False Alarm Rate ◽  
Real Time ◽  
Sliding Window ◽  
Gait Pattern ◽  
Contact Forces ◽  
Pattern Detection ◽  
Constant False Alarm Rate ◽  
Gait Patterns ◽  
Reference Methods

A new approach is proposed to detect the real-time gait patterns adaptively through measuring the ground contact forces (GCFs) by force sensitive resistors (FSRs). Published threshold-based methods detect the gait patterns by means of setting a fixed threshold to divide the GCFs into on-ground and off-ground statuses. However, the threshold-based methods in the literature are neither an adaptive nor a real-time approach. To overcome these drawbacks, this study utilized the constant false alarm rate (CFAR) to analyze the characteristics of GCF signals. Specifically, a sliding window detector is built to record the lasting time of the curvature of the GCF signals and one complete gait cycle could be divided into three areas, such as continuous ascending area, continuous descending area and unstable area. Then, the GCF values in the unstable area are used to compute a threshold through the CFAR. Finally, the new gait pattern detection rules are proposed which include the results of the sliding window detector and the division results through the computed threshold. To verify this idea, a data acquisition board is designed to collect the GCF data from able-bodied subjects. Meanwhile, in order to test the reliability of the proposed method, five threshold-based methods in the literature are introduced as reference methods and the reliability is validated by comparing the detection results of the proposed method with those of the reference methods. Experimental results indicated that the proposed method could be used for real-time gait pattern detection, detect the gait patterns adaptively and obtain high reliabilities compared with the reference methods.

Estimating Off-Road Ground Contact Forces for a Real Time Motion Simulator

2004 ◽  
Author(s):  
Paul W. Richmond ◽  
Randolph A. Jones ◽  
Daniel C. Creighton ◽  
Richard B. Ahlvin
Keyword(s):  
Real Time ◽  
Contact Forces ◽  
Ground Contact ◽  
Time Motion ◽  
Motion Simulator

Reducing Culture Reporting Errors in the Microbiology Laboratory

2019 ◽  
Vol 152 (Supplement_1) ◽  
pp. S131-S132
Author(s):  
Kathryn Hogan ◽  
Beena Umar ◽  
Mohamed Alhamar ◽  
Kathleen Callahan ◽  
Linoj Samuel
Keyword(s):  
Real Time ◽  
Error Rate ◽  
Reporting System ◽  
Error Rates ◽  
Tracking Errors ◽  
Corrective Measures ◽  
Safety Awareness ◽  
Before And After ◽  
Set Up ◽  
System Errors

Abstract Objectives There are few papers that characterize types of errors in microbiology laboratories and scant research demonstrating the effects of interventions on microbiology lab errors. This study aims to categorize types of culture reporting errors found in microbiology labs and to document the error rates before and after interventions designed to reduce errors and improve overall laboratory quality. Methods To improve documentation of error incidence, a self-reporting system was changed to an automatic reporting system. Errors were categorized into five types Gram stain (misinterpretations), identification (incorrect analysis), set up labeling (incorrect patient labels), procedures (not followed), and miscellaneous. Error rates were tracked according to technologist, and technologists were given real-time feedback by a manager. Error rates were also monitored in the daily quality meeting and frequently detected errors were discussed at staff meetings. Technologists attended a year-end review with a manager to improve their performance. To maintain these changes, policies were developed to monitor technologist error rate and to define corrective measures. If a certain number of errors per month was reached, technologists were required to undergo retraining by a manager. If a technologist failed to correct any error according to protocol, they were also potentially subject to corrective measures. Results In 2013, we recorded 0.5 errors per 1,000 tests. By 2018, we recorded only 0.1 errors per 1,000 tests, an 80% decrease. The yearly culture volume from 2013 to 2018 increased by 32%, while the yearly error rate went from 0.05% per year to 0.01% per year, a statistically significant decrease (P = .0007). Conclusion This study supports the effectiveness of the changes implemented to decrease errors in culture reporting. By tracking errors in real time and using a standardized process that involved timely follow-up, technologists were educated on error prevention. This practice increased safety awareness in our micro lab.

RTCONTACT: An Efficient Wheel-Rail Contact Algorithm for Real-Time Dynamic Simulations

2012 ◽  
Author(s):  
N. Bosso ◽  
A. Gugliotta ◽  
N. Zampieri
Keyword(s):  
Real Time ◽  
Computational Efficiency ◽  
Simulation Models ◽  
Experimental Tests ◽  
Contact Forces ◽  
Dynamic Simulations ◽  
Time Dynamic ◽  
Contact Algorithm ◽  
Complex Simulation ◽  
Precise Representation

Determination of contact forces exchanged between wheel and rail is one of the most important topics in railway dynamics. Recent studies are oriented to improve the existing contact methods in terms of computational efficiency on one side and on the other side to develop more complex and precise representation of the contact problem. This work shows some new results of the contact code developed at Politecnico di Torino identified as RTCONTACT; this code, which is an improvement of the CONPOL algorithm, is the result of long term activities, early versions were used in conjunction with MBS codes or in Matlab® environment to simulate vehicle behaviour. The code has been improved also using experimental tests performed on a scaled roller-rig. More recently the contact model was improved in order to obtain a higher computational efficiency that is a required for the use inside of a Real Time process. Benefit of a Real Time contact algorithm is the possibility to use complex simulation models in diagnostic or control systems in order to improve their performances. This work shows several comparisons of the RTCONTACT contact code respect commercial codes, standards and benchmark results.

Three-dimensional Force Perception of Robotic Bipolar Forceps for Brain Tumor Resection

2021 ◽  
Author(s):  
Xiu-Heng Zhang ◽  
Heng Zhang ◽  
Zhen Li ◽  
Gui-Bin Bian
Keyword(s):  
Brain Tumor ◽  
Real Time ◽  
Force Measurement ◽  
Measurement Techniques ◽  
Tumor Resection ◽  
Three Dimensional ◽  
Contact Forces ◽  
Surgical Instruments ◽  
Force Perception ◽  
Brain Tumor Resection

Abstract Three-dimensional force perception is critically important in the enhancement of human force perception to minimize brain injuries resulting from excessive forces applied by surgical instruments in robot-assisted brain tumor resection. And surgeons are not responsive enough to interpret tool-tissue interaction forces. In previous studies, various force measurement techniques have been published. In neurosurgical scenarios, there are still some drawbacks to these presented approaches to forces perception. Because of the narrow, and slim configuration of bipolar forceps, three-dimensional contact forces on forceps tips is not easy to be traced in real-time. Five fundamental acts of handling bipolar forceps are poking, opposing, pressing, opening, and closing. The first three acts independently correspond to the axial force of z, x, y. So, in this paper, typical interactions between bipolar forceps and brain tissues have been analyzed. A three-dimensional force perception technique to collect force data on bipolar forceps tips by installing three Fiber Bragg Grating Sensors (FBGs) on each prong of bipolar forceps in real-time is proposed. Experiments using a tele-neurosurgical robot were performed on an in-vitro pig brain. In the experiments, three-dimensional forces were tracked in real-time. It is possible to experience forces at a minimum of 0.01 N. The three-dimensional force perception range is 0-4 N. The calibrating resolution on x, y, and z, is 0.01, 0.03, 0.1 N, separately. According to our observation, the measurement accuracy precision is over 95%.

Void fraction measurements in breaking waves

2007 ◽  
Vol 463 (2088) ◽  
pp. 3151-3170 ◽  
Author(s):  
C.E Blenkinsopp ◽  
J.R Chaplin
Keyword(s):  
Void Fraction ◽  
Wave Breaking ◽  
Breaking Waves ◽  
Phase Detection ◽  
Bubble Plume ◽  
Two Phase ◽  
Void Fractions ◽  
Highly Sensitive ◽  
Energy Dissipated ◽  
Degree Of Similarity

This paper describes detailed measurements and analysis of the time-varying distribution of void fractions in three different breaking waves under laboratory conditions. The measurements were made with highly sensitive optical fibre phase detection probes and document the rapid spatial and temporal evolutions of both the bubble plume generated beneath the free surface and the splashes above. Integral properties of the measured void fraction fields reveal a remarkable degree of similarity between characteristics of the two-phase flow in different breaker types as they evolve with time. Depending on the breaker type, the energy expended in entraining air and generating splash accounts for a minimum of between 6.5 and 14% of the total energy dissipated during wave breaking.

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