Motion Analysis and Performance Improved Method for 3D LiDAR Sensor Data Compression

Author(s):  
Chenxi Tu ◽  
Eijiro Takeuchi ◽  
Alexander Carballo ◽  
Chiyomi Miyajima ◽  
Kazuya Takeda
Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 516
Author(s):  
Brinnae Bent ◽  
Baiying Lu ◽  
Juseong Kim ◽  
Jessilyn P. Dunn

A critical challenge to using longitudinal wearable sensor biosignal data for healthcare applications and digital biomarker development is the exacerbation of the healthcare “data deluge,” leading to new data storage and organization challenges and costs. Data aggregation, sampling rate minimization, and effective data compression are all methods for consolidating wearable sensor data to reduce data volumes. There has been limited research on appropriate, effective, and efficient data compression methods for biosignal data. Here, we examine the application of different data compression pipelines built using combinations of algorithmic- and encoding-based methods to biosignal data from wearable sensors and explore how these implementations affect data recoverability and storage footprint. Algorithmic methods tested include singular value decomposition, the discrete cosine transform, and the biorthogonal discrete wavelet transform. Encoding methods tested include run-length encoding and Huffman encoding. We apply these methods to common wearable sensor data, including electrocardiogram (ECG), photoplethysmography (PPG), accelerometry, electrodermal activity (EDA), and skin temperature measurements. Of the methods examined in this study and in line with the characteristics of the different data types, we recommend direct data compression with Huffman encoding for ECG, and PPG, singular value decomposition with Huffman encoding for EDA and accelerometry, and the biorthogonal discrete wavelet transform with Huffman encoding for skin temperature to maximize data recoverability after compression. We also report the best methods for maximizing the compression ratio. Finally, we develop and document open-source code and data for each compression method tested here, which can be accessed through the Digital Biomarker Discovery Pipeline as the “Biosignal Data Compression Toolbox,” an open-source, accessible software platform for compressing biosignal data.


2000 ◽  
Vol 203 (11) ◽  
pp. 1659-1669 ◽  
Author(s):  
T. Schwerte ◽  
B. Pelster

The analysis of perfusion parameters using the frame-to-frame technique and the observation of small blood vessels in transparent animals using video microscopy can be tedious and very difficult because of the poor contrast of the images. Injection of a fluorescent probe (fluorescein isothiocynate, FITC) bound to a high-molecular-mass dextran improved the visibility of blood vessels, but the gray-scale histogram showed blurring at the edges of the vessels. Furthermore, injection of the fluorescent probe into the ventricle of small zebrafish (Danio rerio) embryos (body mass approximately 1 mg) often resulted in reduced cardiac activity. Digital motion analysis, however, proved to be a very effective tool for analysing the shape and performance of the circulatory system in transparent animals and tissues. By subtracting the two fields of a video frame (the odd and the even frame), any movement that occurred within the 20 ms necessary for the acquisition of one field could be visualised. The length of the shifting vector generated by this subtraction, represented a direct measure of the velocity of a moving particle, i.e. an erythrocyte in the vascular system. By accumulating shifting vectors generated from several consecutive video frames, a complete trace of the routes over which erythrocytes moved could be obtained. Thus, a cast of the vascular system, except for those tiny vessels that are not entered by erythrocytes, could be obtained. Because the gray-scale value of any given pixel or any given group of pixels increased with the number of erythrocytes passing it, digital motion analysis could also be used to visualise the distribution of blood cells in transparent tissues. This method was used to describe the development of the peripheral vascular system in zebrafish larvae up to 8 days post-fertilisation. At this stage, food intake resulted in a clear redistribution of blood between muscle tissue and the gut, and alpha-adrenergic control of peripheral blood flow was established.


Author(s):  
Felix von Bechtolsheim ◽  
Florian Oehme ◽  
Michael Maruschke ◽  
Sofia Schmidt ◽  
Alfred Schneider ◽  
...  

Abstract Background Coffee can increase vigilance and performance, especially during sleep deprivation. The hypothetical downside of caffeine in the surgical field is the potential interaction with the ergonomics of movement and the central nervous system. The objective of this trial was to investigate the influence of caffeine on laparoscopic performance. Methods Fifty laparoscopic novices participated in this prospective randomized, blinded crossover trial and were trained in a modified FLS curriculum until reaching a predefined proficiency. Subsequently, all participants performed four laparoscopic tasks twice, once after consumption of a placebo and once after a caffeinated (200 mg) beverage. Comparative analysis was performed between the cohorts. Primary endpoint analysis included task time, task errors, OSATS score and a performance analysis with an instrument motion analysis (IMA) system. Results Fifty participants completed the study. Sixty-eight percent of participants drank coffee daily. The time to completion for each task was comparable between the caffeine and placebo cohorts for PEG transfer (119 s vs 121 s; p = 0.73), precise cutting (157 s vs 163 s; p = 0.74), gallbladder resection (190 s vs 173 s; p = 0.6) and surgical knot (171 s vs 189 s; p = 0.68). The instrument motion analysis showed no significant differences between the caffeine and placebo groups in any parameters: instrument volume, path length, idle, velocity, acceleration, and instrument out of view. Additionally, OSATS scores did not differ between groups, regardless of task. Major errors occurred similarly in both groups, except for one error criteria during the circle cutting task, which occurred significantly more often in the caffeine group (34% vs. 16%, p < 0.05). Conclusion The objective IMA and performance scores of laparoscopic skills revealed that caffeine consumption does not enhance or impair the overall laparoscopic performance of surgical novices. The occurrence of major errors is not conclusive but could be negatively influenced in part by caffeine intake.


2001 ◽  
Vol 199 (1-4) ◽  
pp. 77-81 ◽  
Author(s):  
José A Ferrari ◽  
César D Perciante ◽  
Alejandro Lagos ◽  
Erna M Frins

Author(s):  
Steph Michailovs ◽  
Stephen Pond ◽  
Megan Schmitt ◽  
Jessica Irons ◽  
Matthew Stoker ◽  
...  

How team cognition is conceptualized has evolved rapidly in the last decade with the emerging use of a systems approach, moving the focus from the cognition residing in the heads of individuals, to that distributed across the team. This is referred to as ‘distributed cognition’. Increasingly, network approaches are being explored in attempts to model team distributed cognition. The specific domain of interest in the present study is the sociotechnical system within a maritime control room. This comprises human, machine and software agents interacting to interpret sensor data in order to develop a timely and accurate picture of surrounding contacts at sea. To achieve the goal, information is shared or integrated across the maritime control room consoles. The aim of this study was to develop and apply a suite of workload, situation awareness and team performance measures, including network analysis techniques, to examine how the distributed cognition of a team might change as a function of console configuration and information integration within a control room, and how these changes, if any, impact overall team performance. Sixteen teams of six novices conducted two one-hour scenarios operating generic maritime control room positions. Each team completed a one-hour simulation in each of two console configuration layouts with the order counter-balanced (within-subject design). Half the teams conducted the two scenarios in a high integration condition, and half in a low integration condition (between-subjects). The human machine interface (HMI) designs for the high integration condition emerged from a series of task analyses and user-centered design workshops. The emergent cognitively –oriented HMI designs are based on the assumption that each console can freely share information with other consoles. To create an analogue of current, less-integrated, and more stove-piped systems, a low integration condition was created where not all information was shared across consoles, but instead was shared verbally by console operators. Contacts detected at sea were introduced into the simulation and the team’s task was to assess, report and derive a solution (location, course, and speed) for each detected contact. Individual situation awareness was measured through the Situation Present Assessment Method (SPAM) and individual workload through the Air Traffic Workload Indicator Task (ATWIT). Team interaction from the scenarios were video recorded and we applied the Event Analysis of Systemic Teamwork (EAST) approach to examine the task, social and information networks which emerged. Team performance was measured as the accuracy and timeliness of the solutions We found higher information integration lowered average team workload, and improved average team situation awareness and team performance (faster solutions and a more accurate tactical picture). We found no impact of console configuration on team performance or any other dependent measure. The EAST method uncovered patterns in the network analysis that are potentially explanatory for the team workload, situation awareness and performance findings as a function of the information integration manipulation. This experiment showed that there can be reductions in workload, and improvements to situation awareness and performance when information is shared between consoles in a considered design. This has implications for HMI design within a team setting. The set of diagnostic metrics developed were largely effective in examining teamwork and team performance. Acknowledgements. The authors would like to thank Justin Hill (Royal Australian Navy) for his subject matter expertise, Graeme Muller (elmTEK) for his software, technical and infrastructure support, David Munro-Ford (Total Technology Partners) for his simulation programming, Dr Aaron Roberts for his advice on general aspects of the experiment, and Professor Paul Salmon for his advice on EAST.


2013 ◽  
Vol 25 (11) ◽  
pp. 2434-2447 ◽  
Author(s):  
Nguyen Quoc Viet Hung ◽  
Hoyoung Jeung ◽  
Karl Aberer

Sign in / Sign up

Export Citation Format

Share Document