Use of surgical video–based automated performance metrics to predict blood loss and success of simulated vascular injury control in neurosurgery: a pilot study

2021 ◽  
pp. 1-10
Keyword(s):  
Blood Loss ◽  
Vascular Injury ◽  
Performance Metrics ◽  
Surgical Instruments ◽  
Case Volume ◽  
Hemorrhage Control ◽  
Promising Alternative ◽  
Surgical Video ◽  
Task Success ◽  
And Task

OBJECTIVE Experts can assess surgeon skill using surgical video, but a limited number of expert surgeons are available. Automated performance metrics (APMs) are a promising alternative but have not been created from operative videos in neurosurgery to date. The authors aimed to evaluate whether video-based APMs can predict task success and blood loss during endonasal endoscopic surgery in a validated cadaveric simulator of vascular injury of the internal carotid artery. METHODS Videos of cadaveric simulation trials by 73 neurosurgeons and otorhinolaryngologists were analyzed and manually annotated with bounding boxes to identify the surgical instruments in the frame. APMs in five domains were defined—instrument usage, time-to-phase, instrument disappearance, instrument movement, and instrument interactions—on the basis of expert analysis and task-specific surgical progressions. Bounding-box data of instrument position were then used to generate APMs for each trial. Multivariate linear regression was used to test for the associations between APMs and blood loss and task success (hemorrhage control in less than 5 minutes). The APMs of 93 successful trials were compared with the APMs of 49 unsuccessful trials. RESULTS In total, 29,151 frames of surgical video were annotated. Successful simulation trials had superior APMs in each domain, including proportionately more time spent with the key instruments in view (p < 0.001) and less time without hemorrhage control (p = 0.002). APMs in all domains improved in subsequent trials after the participants received personalized expert instruction. Attending surgeons had superior instrument usage, time-to-phase, and instrument disappearance metrics compared with resident surgeons (p < 0.01). APMs predicted surgeon performance better than surgeon training level or prior experience. A regression model that included APMs predicted blood loss with an R2 value of 0.87 (p < 0.001). CONCLUSIONS Video-based APMs were superior predictors of simulation trial success and blood loss than surgeon characteristics such as case volume and attending status. Surgeon educators can use APMs to assess competency, quantify performance, and provide actionable, structured feedback in order to improve patient outcomes. Validation of APMs provides a benchmark for further development of fully automated video assessment pipelines that utilize machine learning and computer vision.

Volunteering as Group Spokesman as a Function of Task Effectiveness, Leader Success, and Task Similarity

1971 ◽  
Vol 28 (3) ◽  
pp. 911-917
Author(s):  
Jack M. Wright ◽  
Morgan Worthy
Keyword(s):  
Task Success ◽  
Group Members ◽  
Task Similarity ◽  
Type Apparatus ◽  
And Task

By reversing the procedure in a Crutchfield-type apparatus, the frequency of adopting the job of spokesman for one's group was studied as a function of the following variables: effectiveness of performance on a previous task, success in influencing the behavior of other group members; and task similarity. Results for 64 male Ss indicate that persons are most willing to function as spokesmen for the group when they have been effective on an earlier task. This is especially likely when the earlier task is similar to the task on which they volunteer as spokesmen or when Ss had been unable to influence other group members' judgments on the previous task. The interpretation is advanced that some types of leadership attempts occur more readily on the basis of feeling of adequacy on the task than on feelings of acceptance as leader (i.e., successful influence).

scholarly journals Resource allocation and task admission control in cloud systems

2021 ◽  
Author(s):  
Haleh Khojasteh
Keyword(s):  
Resource Allocation ◽  
Performance Metrics ◽  
Cloud Model ◽  
Blocking Probability ◽  
Arrival Rate ◽  
Cloud System ◽  
Wide Range ◽  
Priority Scheme ◽  
The Impact ◽  
And Task

The focus of this thesis is solving the problem of resource allocation in cloud datacenter using an Infrastructure-as-a-Service (IaaS) cloud model. We have investigated the behavior of IaaS cloud datacenters through detailed analytical and simulation models that model linear, transitional and saturated operation regimes. We have obtained accurate performance metrics such as task blocking probability, total delay, utilization and energy consumption. Our results show that the offered load does not offer complete characterization of datacenter operation; therefore, in our evaluations, we have considered the impact of task arrival rate and task service time separately. To keep the cloud system in the linear operation regime, we have proposed several dynamic algorithms to control the admission of incoming tasks. In our first solution, task admission is based on task blocking probability and predefined thresholds for task arrival rate. The algorithms in our second solution are based on full rate task acceptance threshold and filtering coefficient. Our results confirm that the proposed task admission mechanisms are capable of maintaining the stability of cloud system under a wide range of input parameter values. Finally, we have developed resource allocation solutions for mobile clouds in which offloading requests from a mobile device can lead to forking of new tasks in on-demand manner. To address this problem, we have proposed two flexible resource allocation mechanisms with different prioritization: one in which forked tasks are given full priority over newly arrived ones, and another in which a threshold is established to control the priority. Our results demonstrate that threshold-based priority scheme presents better system performance than the full priority scheme. Our proposed solution for clouds with mobile users can be also applied in other clouds which their users’ applications fork new tasks.

scholarly journals Resource allocation and task admission control in cloud systems

2021 ◽  
Author(s):  
Haleh Khojasteh
Keyword(s):  
Resource Allocation ◽  
Performance Metrics ◽  
Cloud Model ◽  
Blocking Probability ◽  
Arrival Rate ◽  
Cloud System ◽  
Wide Range ◽  
Priority Scheme ◽  
The Impact ◽  
And Task

The focus of this thesis is solving the problem of resource allocation in cloud datacenter using an Infrastructure-as-a-Service (IaaS) cloud model. We have investigated the behavior of IaaS cloud datacenters through detailed analytical and simulation models that model linear, transitional and saturated operation regimes. We have obtained accurate performance metrics such as task blocking probability, total delay, utilization and energy consumption. Our results show that the offered load does not offer complete characterization of datacenter operation; therefore, in our evaluations, we have considered the impact of task arrival rate and task service time separately. To keep the cloud system in the linear operation regime, we have proposed several dynamic algorithms to control the admission of incoming tasks. In our first solution, task admission is based on task blocking probability and predefined thresholds for task arrival rate. The algorithms in our second solution are based on full rate task acceptance threshold and filtering coefficient. Our results confirm that the proposed task admission mechanisms are capable of maintaining the stability of cloud system under a wide range of input parameter values. Finally, we have developed resource allocation solutions for mobile clouds in which offloading requests from a mobile device can lead to forking of new tasks in on-demand manner. To address this problem, we have proposed two flexible resource allocation mechanisms with different prioritization: one in which forked tasks are given full priority over newly arrived ones, and another in which a threshold is established to control the priority. Our results demonstrate that threshold-based priority scheme presents better system performance than the full priority scheme. Our proposed solution for clouds with mobile users can be also applied in other clouds which their users’ applications fork new tasks.

External Soft-Tissue Hemostatic Clamp Compared to a Compression Tourniquet as Primary Hemorrhage Control Device in Pilot Flow Model Study

2019 ◽  
Vol 34 (02) ◽  
pp. 175-181 ◽  
Author(s):  
Roland Paquette ◽  
Ryan Bierle ◽  
David Wampler ◽  
Paul Allen ◽  
Craig Cooley ◽  
...  
Keyword(s):  
Soft Tissue ◽  
Blood Loss ◽  
Flow Model ◽  
Statistical Significance ◽  
Control Device ◽  
Fluid Loss ◽  
Hemorrhage Control ◽  
Limb Function ◽  
Model Study ◽  
Primary Hemorrhage

Introduction:Acute blood loss represents a leading cause of death in both civilian and battlefield trauma, despite the prioritization of massive hemorrhage control by well-adopted trauma guidelines. Current Tactical Combat Casualty Care (TCCC) and Tactical Emergency Casualty Care (TECC) guidelines recommend the application of a tourniquet to treat life-threatening extremity hemorrhages. While extremely effective at controlling blood loss, the proper application of a tourniquet is associated with severe pain and could lead to transient loss of limb function impeding the ability to self-extricate or effectively employ weapons systems. As a potential alternative, Innovative Trauma Care (San Antonio, Texas USA) has developed an external soft-tissue hemostatic clamp that could potentially provide effective hemorrhage control without the aforementioned complications and loss of limb function. Thus, this study sought to investigate the effectiveness of blood loss control by an external soft-tissue hemostatic clamp versus a compression tourniquet.Hypothesis:The external soft-tissue hemostatic clamp would be non-inferior at controlling intravascular fluid loss after damage to the femoral and popliteal arteries in a normotensive, coagulopathic, cadaveric lower-extremity flow model using an inert blood analogue, as compared to a compression tourniquet.Methods:Using a fresh cadaveric model with simulated vascular flow, this study sought to compare the effectiveness of the external soft-tissue hemostatic clamp versus the compression tourniquet to control fluid loss in simulated trauma resulting in femoral and posterior tibial artery lacerations using a coagulopathic, normotensive, cadaveric-extremity flow model. A sample of 16 fresh, un-embalmed, human cadaver lower extremities was used in this randomized, balanced two-treatment, two-period, two-sequence, crossover design. Statistical significance of the treatment comparisons was assessed with paired t-tests. Results were expressed as the mean and standard deviation (SD).Results:Mean intravascular fluid loss was increased from simulated arterial wounds with the external soft-tissue hemostatic clamp as compared to the compression tourniquet at the lower leg (119.8mL versus 15.9mL; P &lt;.001) and in the thigh (103.1mL versus 5.2mL; P &lt;.001).Conclusion:In this hemorrhagic, coagulopathic, cadaveric-extremity experimental flow model, the use of the external soft-tissue hemostatic clamp as a hasty hemostatic adjunct was associated with statistically significant greater fluid loss than with the use of the compression tourniquet.Paquette R, Bierle R, Wampler D, Allen P, Cooley C, Ramos R, Michalek J, Gerhardt RT. External soft-tissue hemostatic clamp compared to a compression tourniquet as primary hemorrhage control device in pilot flow model study. Prehosp Disaster Med. 2019;34(2):175–181

scholarly journals Using objective robotic automated performance metrics and task-evoked pupillary response to distinguish surgeon expertise

2019 ◽  
Vol 38 (7) ◽  
pp. 1599-1605 ◽  
Author(s):  
Jessica H. Nguyen ◽  
Jian Chen ◽  
Sandra P. Marshall ◽  
Saum Ghodoussipour ◽  
Andrew Chen ◽  
...  
Keyword(s):  
Performance Metrics ◽  
Pupillary Response ◽  
And Task

scholarly journals Pilot Study of a Novel Swine Model for Controlling Junctional Hemorrhage Using the iTClamp in Conjunction With Hemostatic Agents

2019 ◽  
Vol 184 (Supplement_1) ◽  
pp. 367-373 ◽  
Author(s):  
Sean M Stuart ◽  
Gregory Zarow ◽  
Alexandra Walchak ◽  
Julie McLean ◽  
Paul Roszko
Keyword(s):  
Pilot Study ◽  
Blood Loss ◽  
Wound Closure ◽  
Swine Model ◽  
Application Time ◽  
Hemorrhage Control ◽  
New Device ◽  
Hemostatic Agents ◽  
Fda Approval ◽  
Novel Model

Abstract Exsanguinating hemorrhage is a primary cause of battlefield death. The iTClamp is a relatively new device (FDA approval in 2013) that takes a different approach to hemorrhage control by applying mechanism wound closure. However, no previous studies have explored the feasibility of utilizing the iTClamp in conjunction with hemostatic packing. To fill this important gap in the literature, a novel swine model was developed, and a total of 12 trials were performed using QuikClot Combat Gauze or XSTAT sponges in conjunction with the iTClamp to treat arterial injuries through 5 cm or 10 cm skin incisions in the groin, axilla, or neck. First-attempt application success rate, application time, and blood loss were recorded. Hemostasis was achieved on all wounds, though reapplication was required in one Combat Gauze and three XSTAT applications. Application averaged ~50% slower for Combat Gauze (M = 41 seconds, 95%CI: 22–32 seconds) than for XSTAT (M = 27 seconds, 95%CI: 35–47 seconds). XSTAT application was faster than Combat Gauze for each wound location and size. The 10 cm wounds took ~10 seconds (36%) longer to close (M = 27 seconds, 95%CI: 35–47 seconds) than the 5 cm wounds (M = 27 seconds, 95%CI: 35–47 seconds). Blood loss was similar for Combat Gauze (M = 51 mL, 95%CI: 25–76 mL) and XSTAT (M = 60 mL, 95%CI: 30–90 mL). Blood loss was roughly twice as great for 10 cm wounds (M = 73 mL, 95%CI: 47–100 mL) than for 5 cm wounds (M = 38 mL, 95%CI: 18–57 mL). This pilot study supports the feasibility of a novel model for testing the iTClamp in conjunction with hemostatic packing towards controlling junctional hemorrhage.

Assessment of Groin Application of Junctional Tourniquets in a Manikin Model

2016 ◽  
Vol 31 (4) ◽  
pp. 358-363 ◽  
Author(s):  
John F. Kragh ◽  
Matthew P. Lunati ◽  
Chetan U. Kharod ◽  
Cord W. Cunningham ◽  
Jeffrey A. Bailey ◽  
...  
Keyword(s):  
Blood Loss ◽  
Blood Volume ◽  
Mixed Model ◽  
Pairwise Comparison ◽  
Ease Of Use ◽  
User Preference ◽  
Publication Type ◽  
Hemorrhage Control ◽  
Total Blood ◽  
Significant Difference

AbstractIntroductionTo aid in preparation of military medic trainers for a possible new curriculum in teaching junctional tourniquet use, the investigators studied the time to control hemorrhage and blood volume lost in order to provide evidence for ease of use.HypothesisModels of junctional tourniquet could perform differentially by blood loss, time to hemostasis, and user preference.MethodsIn a laboratory experiment, 30 users controlled simulated hemorrhage from a manikin (Combat Ready Clamp [CRoC] Trainer) with three iterations each of three junctional tourniquets. There were 270 tests which included hemorrhage control (yes/no), time to hemostasis, and blood volume lost. Users also subjectively ranked tourniquet performance. Models included CRoC, Junctional Emergency Treatment Tool (JETT), and SAM Junctional Tourniquet (SJT). Time to hemostasis and total blood loss were log-transformed and analyzed using a mixed model analysis of variance (ANOVA) with the users represented as random effects and the tourniquet model used as the treatment effect. Preference scores were analyzed with ANOVA, and Tukey’s honest significant difference test was used for all post-hoc pairwise comparisons.ResultsAll tourniquet uses were 100% effective for hemorrhage control. For blood loss, CRoC and SJT performed best with least blood loss and were significantly better than JETT; in pairwise comparison, CRoC-JETT (P < .0001) and SJT-JETT (P = .0085) were statistically significant in their mean difference, while CRoC-SJT (P = .35) was not. For time to hemostasis in pairwise comparison, the CRoC had a significantly shorter time compared to JETT and SJT (P < .0001, both comparisons); SJT-JETT was also significant (P = .0087). In responding to the directive, “Rank the performance of the models from best to worst,” users did not prefer junctional tourniquet models differently (P > .5, all models).ConclusionThe CRoC and SJT performed best in having least blood loss, CRoC performed best in having least time to hemostasis, and users did not differ in preference of model. Models of junctional tourniquet performed differentially by blood loss and time to hemostasis.KraghJFJr, LunatiMP, KharodCU, CunninghamCW, BaileyJA, StockingerZT, CapAP, ChenJ, AdenJK3d, CancioLC. Assessment of groin application of junctional tourniquets in a manikin model. Prehosp Disaster Med. 2016;31(4):358–363.

Impact of Pre-Study Exploration on System Usability Scale and Task Success Rates for Automotive Interfaces

2017 ◽  
Author(s):  
Satheesh Kumar Chandran ◽  
James Forbes ◽  
Carrie Bittick ◽  
Kathleen Allanson ◽  
Santosh Erupaka ◽  
...  
Keyword(s):  
Success Rates ◽  
System Usability Scale ◽  
System Usability ◽  
Task Success ◽  
And Task

Appearance and Task Success in Novel Avatars

2015 ◽  
Vol 24 (4) ◽  
pp. 335-346 ◽  
Author(s):  
Andrea Stevenson Won ◽  
Jeremy N. Bailenson ◽  
Jaron Lanier
Keyword(s):  
The Body ◽  
The Novel ◽  
The Third ◽  
Task Success ◽  
Normal Human ◽  
One To One ◽  
Study Participants ◽  
And Task

Novel avatar bodies are ones that are not controlled in a one-to-one relationship between the user’s body and the avatar body, for example, when the avatar’s arms are controlled by the user’s legs, or, when the avatar has a third arm. People have been shown to complete tasks more successfully when controlling novel avatar bodies than when controlling avatars that conform to the normal human configurations, when those novel avatars are better suited to the task (Won, Bailenson, Lee, & Lanier, 2015). However, the novel avatars in such studies tend to follow two conventions. First, the novel avatars still resemble biological forms, and second, the novel extensions of the avatar are connected to the avatar body. In the following study, participants operated bodies with three arms. We examined the interaction between biological appearance of the third arm and whether it was attached to the body. There was a significant effect of biological appearance on performance, such that participants inhabiting an avatar with a biological appearance did worse overall. There was also an interaction with biological appearance and an extension that appeared detached from the participant’s body such that participants in this condition performed most poorly overall. We propose a relationship between self-reported presence and task success, and discuss the implications of these findings for the design, implementation, and use of novel avatars.

scholarly journals Measuring User Experience on Massive Open Online Course with User-Centered Metrics: A Case Study

10.47028/096 ◽  
2019 ◽  
Author(s):  
Royanul Fitron ◽  
Sri Suning Kusumawardani ◽  
Ridi Ferdiana
Keyword(s):  
Student Satisfaction ◽  
User Experience ◽  
Massive Open Online Course ◽  
Research User ◽  
Task Success ◽  
E Learning ◽  
Enhanced Learning ◽  
And Task ◽  
User Centered

Evaluation of user experience (UX) in learning applications is now very important. Agood UX on MOOC will have an impact on increased completion rates and student satisfaction,student engagement, enhanced learning, and minimizing course implementation rework. In thisstudy, the authors use MOOC called E-learning: Open of Knowledge Sharing (eLOK) as theobject of research. User-centered metrics or known as HEART framework consisting of fivemetrics, including Happiness, Engagement, Adoption, Retention and Task Success. Theframework that the authors used to measure the UX of eLOK is HEART metrics. The instrumentthat used in this study is a questionnaire consists of 33 statements which delivered to 94 studentsas the sample of the research, with the the number of population 1500. The questionnaire hasbeen validated using SPSS 23 as the tools. The result of the validation is all the items of thequestionnaire are valid and reliable with the percentage of reliability is 96%. The result of thisstudy showed that the metrics obtained by Happiness was 76.5%, Engagement was 72.1%,Adoption was 73.6%, Retention was 72.6%, and Task Success was 78.6%. To achieve the GoalSignal-Metrics set on the HEART framework, it is necessary to re-design the eLOK display bypaying attention to UX and UI aspects, changing the greeting with user-guidance, improving pushnotification features and navigation.

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