Task Load Index Research Articles

A Randomized Pilot Trial of Virtual Reality Surgical Planning for Head and Neck Oncologic Resection.

Application of virtual reality (VR) for surgical planning may improve clinical outcomes for head and neck cancer (HNC) resection. There is a lack of randomized trials and meaningful metrics to assess such technological applications. Our objective was to evaluate the feasibility of a VR protocol for oncologic surgical planning and assess the impact on surgical outcomes. A randomized controlled trial utilizing a VR Case Enhancement Protocol (VRCEP) versus standard of care (SOC) surgical planning was conducted. The primary endpoint was feasibility, defined as >80% successful VRCEPs. Metrics included surgeon task-load burden (TLB) using the NASA Task-Load Index and "margin events," defined as "the need for defect-driven margins, positive frozen margins, and/or positive final margins." Margin events were used to calculate a margin event score (MES) per case and margin event rate (MER) per cohort. Thirty-four patients were included in the final analysis (17 VRCEP, 17 SOC) with 94.4% of eligible VRCEP cases completed (17/18). Surgeon TLB was unchanged with VRCEP. Cases undergoing VRCEP were associated with a lower mean MES (0.27 vs. 0.94, p = 0.014) and MER (11.6% vs. 35.6%, p = 0.0041). VRCEP was associated with decreased defect-driven margins (10% vs. 53.3%, p = 0.032). Although not statistically significant, positive frozen and final margin rates were lower in VRCEP. Completion of the VRCEP was feasible with no significantincrease in surgeon TLB appreciated. VRCEP yielded fewer MEs. Further investigation into the benefit of VR in HNC resection is warranted. Margin events may represent useful metrics for assessing novel surgical technologies. 2 Laryngoscope, 2024.

Evaluating the Usability of a Remote Ischemic Conditioning Device for Pre-Hospital Stroke Management: Insights from Paramedic Simulations

Background/Objectives: In acute stroke, often-prolonged hospital transport times present an opportunity for early interventions to salvage brain tissue. Remote ischemic conditioning (RIC), where brief cycles of ischemia–reperfusion in a limb are induced to protect the brain, is a promising treatment for this setting. We assessed the usability of a novel RIC system in a simulated emergency response scenario. Methods: Paramedics were asked to use the RIC device in an emergency stroke care and ambulance transport simulation, overseen by a confederate. Feedback on device use was collected through questionnaires, including the System Usability Scale (SUS) and the NASA Task Load Index (NASA-TLX), and a semi-structured interview. Questionnaire responses were summarized using descriptive statistics; interview transcripts were analyzed thematically. Results: Nine paramedics (including the confederate) participated, with a mean of 10.0 ± 10.3 years of professional experience. Questionnaire responses indicated high device usability (mean SUS score: 85.3 ± 12.9 out of 100) and low task-related demands, effort, and frustration (mean NASA-TLX domain scores: ≤3.9 out of 20). Seven paramedics stated they would use the device in daily practice. They expressed concerns related to display screen clarity, interference with standard procedures, cable management, device fragility, and patient discomfort. Suggested improvements included adding indicators of device performance and refining the cuff design. Conclusions: While the device was considered easy to use, paramedics also identified important areas of improvement. With a small, localized study sample, our findings are primarily applicable to the refinement of the RICovery system for use in future clinical trials in the same healthcare setting. However, feedback on the importance of mitigating potential interference of newly introduced procedures with those already established, robustness of equipment, and effective paramedic–patient communication may also help inform the design of other pre-hospital interventions.

Impact of prior experience and gender on cognitive load during initial drone use

The purpose of this demonstration study was to determine the effect of prior experiences and gender on cognitive demands at the initial educational technology experience. The task of drone operation was selected as a novel educational technological tool and videogame use was determined to be a tangential prior experience. Through the framework of embodied cognition, the NASA Task Load Index was used to measure cognitive demand. Practicing middle- and high-school science teachers were recruited to participate in this study. Participants operated drones at three instances over two weeks. An additional challenging task was also presented. A mixed ANOVA suggested a significant interaction between videogame use and time: F(2, 28) = 3.77, p<\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p<$$\\end{document} 0.05. A significant interaction between gender and time was also observed: F(2, 29) = 3.72, p<\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$p<$$\\end{document} 0.05. For both prior experience and gender, the differences were observed at the first instance of drone operation and not at subsequent trials. Results suggest prior experience and gender may only affect cognitive load at the initial experience and leveling of cognitive load occurs with continued practice. These findings can support an educator’s planning for drone-based activities and help to mitigate the stigma of gender differences regarding technology use. Additionally, these findings support the need to examine and enhance related and transferable skills, such as hand–eye coordination and spatial thinking, to lessen cognitive load at the initial educational experience.

Influence of Distraction Factors on Performance in Laparoscopic Surgery in Immersive Virtual Reality: Study Protocol of a Cross-Over Trial in Medical Students and Residents-DisLapVR.

Working in an operating room (OR) is physically and mentally challenging: the operation itself demands the surgeon's full attention, while time and cost efficiency constraints, daily planning, and emergency care interfere with the procedure. Thus, multitasking becomes an integral surgical competence. This study aims to examine the effect of disruptions during surgery in a highly immersive virtual reality (IVR) operation environment combined with a virtual reality (VR) laparoscopy simulator. This study aims to identify distractions in the OR and their importance in the clinical setting. An IVR environment was created using a high-resolution, stereoscopic 360° video of the OR. Different distractions were identified, classified as auditory, visual, or audio-visual, and recorded accordingly. The surrounding was combined with a VR laparoscopic simulator. Participants-medical students and surgical residents-received proficiency-based training in basic laparoscopic skills and were blinded to the aim of the experiment. Following a cross-over design, each participant received a unique order of virtual distraction factors while performing tasks on the laparoscopic simulator. During the experiment, subjective passing of time, stress, heart rate, and visually induced motion sickness are recorded. After the experiment, validated questionnaires for usability, immersion, and stress were completed, as well as subjective evaluation of the distractions. The questionnaires used included the system usability scale, Self-Assessment Manikin score, National Aeronautics and Space Administration Task Load Index, and the immersion rating scale as described by Nichols. Performance in the laparoscopic tasks in relation to distractions will be evaluated by the Wilcoxon test and ANOVA for continuous variables. Subgroup analyses in regard to age, gender, and expertise (medical students vs surgical residents) are planned. The described trial started in August 2022 and is ongoing. By July 2024, a total of 30 medical students and 9 surgeons have completed the study. We present a study protocol aiming to identify the impact of different disruptions in OR during laparoscopic training in IVR. Hence, it may lead to an improved awareness of distractions and facilitate accommodations toward an improved work environment. Prior research leads to the hypothesis that the performance of a more experienced surgeon is less impacted by distractions than the performance of inexperienced surgeons and medical students. Furthermore, we investigate which type of distraction has the largest impact on performance. With this knowledge, specific multitasking training can be devised, which may be particularly useful in medical education, for which VR might play a leading role. Additionally, workplace surroundings in the OR can be optimized with this knowledge. German Registry for Clinical Trials DRKS00030033; https://drks.de/search/en/trial/DRKS00030033. DERR1-10.2196/59014.

Addressing mental health challenges in college students: A biomechanical approach to mitigating stress and cognitive load through physical intervention strategies

The main objective of this investigation is to find out how biomechanical actions, such as physical activity programs, balanced adjustments, and mindfulness-based posture correction, are successful at reducing Cognitive Load (CL) and levels of stress among college students. Mechanical adjustments decreased stress, physical activity reduced CL, and mindfulness-based posture correction improved Mental Health (MH), according to a long-term experiment with 28 students from four distinct educational fields. Investigators examined students’ stress, CL, and BH levels monthly. The outcome results dealt with all three predictions. A student’s Perceived Stress Scale (PSS) score dropped from 24.66 to 18.10 (mean difference = 6.56, t = 4.82, p = 0.0001) after experiencing practical changes, demonstrating a significant decrease in stress levels. Following the exercise support, CL, as determined by the NASA Task Load Index (NASA-TLX), dropped from 65.38 to 54.23 (mean difference = 11.15, t = 5.29, p = 0.00005). Ratings for BH increased significantly after exercising mindfulness-based posture correction (from 78.63 to 85.13; mean difference = −6.50, t = −4.92, p = 0.00007). The median variation in PF (VO2 Max) went from 40.46 to 45.11 (t = −3.78, p = 0.0012), and the difference in value was −4.65.

Integration of Augmented Reality in Temporal Bone and Skull Base Surgeries.

Augmented reality technologies provide transformative solutions in various surgical fields. Our research focuses on the use of an advanced augmented reality system that projects 3D holographic images directly into surgical footage, potentially improving the surgeon's orientation to the surgical field and lowering the cognitive load. We created a novel system that combines exoscopic surgical footage from the "ORBEYE" and displays both the surgical field and 3D holograms on a single screen. This setup enables surgeons to use the system without using head-mounted displays, instead viewing the integrated images on a 3D monitor. Thirteen surgeons and surgical assistants completed tasks with 2D and 3D graphical surgical guides. The NASA Task Load Index was used to assess mental, physical, and temporal demands. The use of 3D graphical surgical guides significantly improved performance metrics in cochlear implant surgeries by lowering mental, physical, temporal, and frustration levels. However, for Bonebridge implantation, the 2D graphical surgical guide performed better overall (p = 0.045). Participants found the augmented reality system's video latency to be imperceptible, measuring 0.13 ± 0.01 s. This advanced augmented reality system significantly improves the efficiency and precision of cochlear implant surgeries by lowering cognitive load and improving spatial orientation.

Patient Perception of Mental Effort in Voice Therapy

ObjectiveOne challenge in voice therapy is that mastering new vocal techniques is inherently cognitively effortful. While effort is critical for learning, it can also lead to frustration and reduced patient engagement. The purpose of this study was to investigate the relationship between patient-perception of voice handicap and mental effort in voice therapy, and to determine if different therapy approaches and stimuli elicit different perceptions of mental effort. MethodsA non-experimental, prospective investigation was conducted with adult patients receiving voice therapy. Prior to therapy initiation, patients completed the Voice Handicap Index-10 (VHI-10) to quantify perceived severity of their voice disorders. To assess mental effort, a Borg mental effort scale and the NASA Task Load Index (NASA-TLX) were administered following each therapy session. Therapy type and treatment stimulus/level of treatment hierarchy was documented for each session. Kruskal-Wallis H-test was used to compare differences in baseline VHI-10 and mental effort among voice disorder diagnoses. Pairwise comparisons, linear random-intercept mixed-effects model, and generalized estimating equation method were used to determine correlation between VHI-10 and mental effort, and therapy type, stimulus, and effort. ResultsTwenty-seven participants (89% female, 60% white) completed the study. There was no significant difference in VHI-10 or baseline perceptions of mental effort between races or among voice disorder diagnoses. There was a significant positive correlation between VHI-10 scores and session 1 mental effort. There was no significant difference in effort ratings among therapy types, but effort was rated as significantly greater for therapy stimuli that involved connected speech practice than other stimuli. Perceived mental effort significantly decreased over time. DiscussionVoice therapy imposes a cognitive load on the patient, and is particularly challenging for individuals with more severely perceived voice disorders. Further, patients think voice treatment approaches that utilize connected speech stimuli are more effortful than those that use simple stimuli, regardless of treatment target (e.g. resonance, flow).

Relationship of workload with fatigue and sleep quality in female exercisers

Fatigue is a critical issue for female exercisers that may lead to medical errors, degradation in performance, decreased mental acuity, and social problems. Poor sleep quality is also a contributing factor to the fatigue experienced by female exercisers. Overwork is a factor causing poor sleep quality in female exercisers. The present study aimed to investigate the relationship between workload, fatigue, and sleep quality among female exercisers in the Sleman Regency District. A cross-sectional study was conducted from December 2023 to March 2024 using a self-reported questionnaire. The questionnaire included the Workload questionnaire adapted from the National Aeronautics and Space Administration Task Load Index, the Leeds Sleep Evaluation Questionnaire (LSEQ), and the Subjective Self Rating of Fatigue Assessment Scale (FAS) from the WHO Quality of Life Assessment Instrument (WHOQOL-EF) with 200 respondents in Sleman Regency. The PLS equation model was used to analyze the relationship between workload, sleep quality, fatigue, and the indicators of each instrument. The results showed that female exercisers who were over 40 years old, had children at home, had informal work, did daily exercise in the evening, and had a work schedule in the night had a higher risk of fatigue and poorer sleep quality than those below 40 years old who didn’t have children at home, had formal work, did daily exercise in the morning, and had a work schedule in the morning. A subjective self-rating test was used to measure fatigue, sleep quality, and workload. The training load and intensity of exercise programs influenced fatigue levels, which affected sleep quality. Female exercisers may face challenges balancing exercise with other commitments, such as family responsibilities, leading to overtraining and fatigue. The PLS model test showed a significant relationship between sleep quality and the level of perceived fatigue (p-value = 0.000). Workload significantly impacts sleep quality and fatigue risk in female exercisers. Therefore, managing workload is crucial to improving sleep quality and reducing fatigue risk.

Perceptions of Cognitive Load and Workload in Nurse Handoffs: A Comparative Study Across Differing Patient-Nurse Ratios and Acuity Levels.

Medical errors, often resulting from miscommunication and cognitive lapses during handoffs, account for numerous preventable deaths and patient harm annually. This research examined nurses' perceived workload and cognitive load during handoffs on hospital units with varying patient acuity levels and patient-nurse ratios. Conducted at a southeastern US medical facility, the study analyzed 20 handoff dyads using the National Aeronautics and Space Administration Task Load Index to measure perceived workload and cognitive load. Linear regressions revealed significant associations between patient acuity levels, patient-nurse ratios, and National Aeronautics and Space Administration Task Load Index subscales, specifically mental demand (P = .007) and performance (P = .008). Fisher exact test and Wilcoxon rank sum test showed no significant associations between these factors and nurses' roles (P > .05). The findings highlight the need for targeted interventions to manage workload and cognitive load, emphasizing standardized handoff protocols and technological aids. The study underscores the variability in perceived workload and cognitive load among nurses across different units. Medical-surgical units showed higher cognitive load, indicating the need for improved workload management strategies. Despite limitations, including the single-center design and small sample size, the study provides valuable insights for enhancing handoff communications and reducing medical errors.

The Use of Heart Rate Measures to Evaluate Stress Levels among Air Traffic Controllers

This paper looks at the possibility of using a heart rate monitor to evaluate stress levels among Air Traffic Controllers (ATCOs). Air Traffic Control (ATC) service requires constant good planning, situation awareness, and always making sound decisions. A study was conducted on two ATCOs for three complete work cycles: the morning shift from 8 a.m. to 4 p.m., the afternoon shift from 4 p.m. to 12 a.m., and the night shift from 12 a.m. to 8 a.m. Both participants have different roles, with Subject A being a planner controller while Subject B is a radar controller. The study used the NASA Task Load Index (NASA-TLX) survey to collect the subjective workload rating and a heart rate monitor armband to measure the heart rate reading of an ATCO and then compare it with the number of aircraft within the controlled area. Two hypotheses were investigated: the first one is the relationship between the number of traffic and heart rate readings, and the second hypothesis is the relationship between the elapsed working time and heart rate reading. The Spearman correlation test has been used to determine these relationships. Based on the results, a p-value of less than 0.05 and a positive correlation indicates a significant relationship between the number of aircraft and heart rate readings for both subjects. Elapsed time and heart rate measurement, on the other hand, do not significantly correlate with a p-value greater than 0.05 and a negative correlation was produced for both subjects. The unweighted NASA-TLX workload measure confirmed the findings for Subject A but not for Subject B. This might be due to the different roles carried out by both subjects during the experiment. This shows that different work tasks resulted in different workload-induced factors. The results show a promising outcome of using a heart rate monitor to evaluate stress levels among ATCOs. However, more subjects were needed to enable the use of this concept for future purposes of measuring ATCO stress levels to manage workload.

Tele-education in point-of-care ultrasound training

BackgroundTraditionally, ultrasound skills have been taught through a one-on-one approach, where instructors physically guide learners’ hands at the bedside or in the workshop. However, this method is frequently challenged by scheduling and cost limitations. Our objective was to create a tele-education model for point-of-care ultrasound training and evaluate its effectiveness and its impact on learners’ perceived workload compared to conventional education and self-directed learning methods.MethodsWe conducted a 3-arm randomized trial, comparing tele-education (TE), conventional education (CE) and self-directed learning (SL) methods. All subjects underwent online didactic lectures prior to a hands-on ultrasound workshop. The TE group utilized an ultrasound machine equipped with a speakerphone, a webcam for direct visualization of learner’s hand maneuvers, and an analog-to-video converter for the real-time streaming of ultrasound images. This configuration enabled remote instructors to provide immediate verbal feedback to learners. In contrast, the CE group received in-person coaching, while the SL group had no instructors present. Following the coaching session, subjects completed a scenario-based skill test and a survey on the National Aeronautics and Space Administration task load index (NASA-TLX) to measure their ultrasound competency and perceived workload, respectively.ResultsTwenty-seven ultrasound novices were randomly allocated into 3 groups. The median skill test score of TE, CE, and SL was 22 [interquartile range (IQR): 18–28], 24 [IQR: 21–31], and 16 [IQR: 15–18], respectively (p < 0.01). Pairwise comparisons of median test scores of 3 groups demonstrated a statistical significance in comparisons of TE vs. SL (22 vs. 16, p = 0.01) and CE vs. SL (24 vs. 16, p < 0.01), but not in TE vs. CE (22 vs. 24, p = 0.56). There was no statistical significance observed in the median NASA-TLX scores among the 3 groups; 54 [IQR:47–61] in TE, 57 [IQR:22–64] in CE, and 66 [IQR: 66–72] in SL (p = 0.05).ConclusionsOur tele-education model was more effective than self-directed learning. There was no statistically significant difference in effectiveness between the tele-education and the conventional education groups. Importantly, tele-education did not impose a significantly higher workload on learners compared to conventional education or self-directed learning. Tele-education has a substantial potential as an alternative to conventional ultrasound training.

A case study of the subjective workload of forest equipment operators in South Carolina

ABSTRACT Logging operations in the Southern United States have become more mechanized over time. However, extensive use of complex and heavy forest machineries for long durations increases operator workload, especially the cognitive demand. Working under demanding conditions can decrease the health of forest equipment operators over time, reducing productivity and increasing the risk of accidents. This study provides an initial assessment of the workload of logging equipment operators during timber harvesting operations using conventional wheeled feller-buncher, grapple skidder, and knuckle-boom loader harvesting systems by assessing the subjective workload of the logging equipment operators in South Carolina. In addition, we observed the heart rate of equipment operators to study the activities causing excessive physical and mental workload. Logging equipment operators self-evaluated their workload using the NASA Task Load Index, a subjective measure of workload. Results show no significant difference in the overall workload of equipment operators working at clearcut and thinning sites. The workload dimensions of Effort and Frustration contributed the most to the overall workload, while Performance had the least contribution. Sudden heart rate spikes occurred when operators conducted physical activities such as clearing debris from a felling head but were otherwise unobserved.

Speech-mediated manipulation of da Vinci surgical system for continuous surgical flow

AbstractWith the advent of robot-assisted surgery, user-friendly technologies have been applied to the da Vinci surgical system (dVSS), and their efficacy has been validated in worldwide surgical fields. However, further improvements are required to the traditional manipulation methods, which cannot control an endoscope and surgical instruments simultaneously. This study proposes a speech recognition control interface (SRCI) for controlling the endoscope via speech commands while manipulating surgical instruments to replace the traditional method. The usability-focused comparisons of the newly proposed SRCI-based and the traditional manipulation method were conducted based on ISO 9241-11. 20 surgeons and 18 novices evaluated both manipulation methods through the line tracking task (LTT) and sea spike pod task (SSPT). After the tasks, they responded to the globally reliable questionnaires: after-scenario questionnaire (ASQ), system usability scale (SUS), and NASA task load index (TLX). The completion times in the LTT and SSPT using the proposed method were 44.72% and 26.59% respectively less than the traditional method, which shows statistically significant differences (p &lt; 0.001). The overall results of ASQ, SUS, and NASA TLX were positive for the proposed method, especially substantial reductions in the workloads such as physical demands and efforts (p &lt; 0.05). The proposed speech-mediated method can be a candidate suitable for the simultaneous manipulation of an endoscope and surgical instruments in dVSS-used robotic surgery. Therefore, it can replace the traditional method when controlling the endoscope while manipulating the surgical instruments, which contributes to enabling the continuous surgical flow in operations consequentially.

Effects of simulated driving task screen background color combinations on visual performance and visual fatigue

ABSTRACT In-car smart devices, such as touchscreen control systems, internet interfaces and hands-free phone functions can cause problems affecting driver comfort, visual fatigue and performance, resulting in decreased reaction times, increasing the likelihood of accidents. This study utilizes a touchscreen display and driving simulator as the operational tools in experiments designed to investigate how changes in screen brightness and different color combinations affect the visual performance and the level of visual fatigue of the driver. Specifically, the aim is to explore the impact of changes in brightness and color combinations on visual fatigue and whether there are interactions between them. During the experimental process, relevant data, including the Critical Fusion Frequency (CFF), touchscreen offset, and the NASA Task Load Index (NASA-TLX), are collected and then analyzed using the SPSS statistical software to provide objective and reliable supporting data and valuable insights to related research fields. The experimental results show that the environmental illumination significantly affects the touchscreen offset, CFF and the NASA-TLX), while the color combination significantly affects touchscreen offset (movement and rotation) and the NASA-TLX.

Electromyographically controlled prosthetic wrist improves dexterity and reduces compensatory movements without added cognitive load

Wrist function is a top priority for transradial amputees. However, the combined functional, biomechanical, and cognitive impact of using a powered prosthetic wrist is unclear. Here, we quantify task performance, compensatory movements, and cognitive load while three transradial amputees performed a modified Clothespin Relocation Task using two myoelectric prostheses with and without the wrists. The two myoelectric prostheses include a commercial prosthesis with a built-in powered wrist, and a newly developed inexpensive prosthetic wrist for research purposes, called the “Utah wrist”, that can be adapted to work with various sockets and prostheses. For these three participants, task failure rate decreased significantly from 66% ± 12% without the wrist to 39% ± 9% with the Utah wrist. Compensatory forward leaning movements also decreased significantly, from 24.2° ± 2.5 without the wrist to 12.6° ± 1.0 with the Utah wrist, and from 23.6° ± 7.6 to 15.3° ± 7.2 with the commercial prosthesis with an integrated wrist. Compensatory leftward bending movements also significantly decreased, from 20.8° ± 8.6 to 12.3° ± 5.3, for the commercial with an integrated wrist. Importantly, simultaneous myoelectric control of either prosthetic wrist had no significant impact on cognitive load, as assessed by the NASA Task Load Index survey and a secondary detection response task. This work suggests that functional prosthetic wrists can improve dexterity and reduce compensation without significantly increasing cognitive effort. These results, and the introduction of a new inexpensive prosthetic wrist for research purposes, can aid future research and development and guide the prescription of upper-limb prostheses.

Robotic-Assisted Navigation in Single-Level Transforaminal Lumbar Interbody Fusion Reduces Surgeons’ Mental Workload Compared With Fluoroscopic and Computed Tomographic Techniques: A Nonrandomized Prospective Controlled Trial

Background: Pedicle screw placement during spine fusion is physically and mentally demanding for surgeons. Consequently, spine surgeons can become fatigued, which has implications for both patient safety and surgeon well-being. Purpose: We sought to assess the cognitive workload of surgeons placing pedicle screws using robotic-assisted navigation compared with fluoroscopic and computed tomography (CT)-assisted placement. Methods: We performed a nonrandomized prospective controlled trial to compare the cognitive workload of 3 surgeons performing single-level minimally invasive transforaminal lumbar interbody fusion (MI-TLIF) using robotic, CT, or fluoroscopic navigation on 25 patients (15 in the robotic navigation group and 10 in the nonrobotic group). Immediately after each procedure, surgeons submitted the National Aeronautics and Space Administration–Task Load Index (NASA-TLX), which has 6 subscales: mental demands, physical demands, temporal demands, performance, effort, and frustration. Four tasks associated with pedicle screw placement were assessed independently: (1) screw planning, (2) calibrating robot/obtaining imaging/registration, (3) pedicle cannulation, and (4) screw placement. Patient demographics and surgical characteristics were obtained and reviewed. Results: Surgeons’ self-reported cognitive workload was significantly reduced when using robotic-assisted navigation versus CT/fluoroscopic navigation. Workload was reduced for screw planning, pedicle cannulation, and screw placement. In addition, there were significant reductions in each subdomain for these 3 tasks, encompassing mental demand, physical demand, temporal demand, effort, and frustration with improved task performance. Conclusions: This study found significant reductions in mental workload with improved perceived performance for robotic-assisted pedicle screw placement compared with fluoroscopic and CT-navigation techniques. Lowering the cognitive burden associated with screw placement may allow surgeons to address the remainder of the operative case with less decision fatigue, prevent complications, and increase surgeon wellness.

Physical therapist burden delivering gait training for a patient with lateropulsion after stroke during inpatient rehabilitation: a single-case design

Background/Aims Gait training for patients with lateropulsion after stroke improves outcomes (eg reduced lateropulsion and improved function) but can be burdensome on the physical therapist. This study describes the physical therapist burden and performance of a patient with moderate lateropulsion during three gait training approaches during inpatient rehabilitation. Methods A physical therapist delivered gait training (one session each of overground robotic exoskeleton, overground supported walking, and body weight-supported treadmill training) for a patient with lateropulsion (scoring 8 out of 17 on the Burke Lateropulsion Scale). Outcomes were physiological burden (heart rate, metabolic equivalents, respiratory exchange ratio and energy expenditure), which were measured via a wearable metabolic system and perceptual burden (National Aeronautics and Space Administration Task Load Index) on the physical therapist. Patient performance (step count, time walking, time spent upright and time in moderate-to-vigorous intensity) was recorded. Results During overground robotic exoskeleton gait training, the physical therapist's physiological metrics included an average heart rate of 116 beats per minute (minimum–maximum: 98–127, time in moderate-to-vigorous intensity was 0%), average metabolic equivalents of 3.2 (minimum–maximum: 1.7–4.3), a respiratory exchange ratio of 0.79 (minimum–maximum: 0.70–0.93), an energy expenditure of 228 kcal/hour and a perceptual burden of 33.3. The patient walked 228 steps, spent 15.4 minutes upright, 8.7 minutes walking and achieved 0% in moderate-to-vigorous intensity. During overground supported walking, the physical therapist's metrics included an average heart rate of 145 beats per minute (minimum–maximum: 113–164, time in moderate-to-vigorous intensity was 87%), average metabolic equivalents of 4.7 (minimum–maximum: 2.7–6.0), a respiratory exchange ratio of 0.96 (minimum–maximum: 0.81–1.16), an energy expenditure of 343 kcal/hour and a perceptual burden of 60.8. The patient walked 588 steps, spent 19.6 minutes upright, 10.5 minutes walking and achieved 38% in moderate-to-vigorous intensity. During body weight-supported treadmill training, the physical therapist's metrics included an average heart rate of 112 beats per minute (minimum–maximum: 69–137, time in moderate-to-vigorous intensity was 34%), average metabolic equivalents of 3.9 (minimum–maximum: 3.2–4.4), a respiratory exchange ratio of 0.89 (minimum–maximum: 0.82–0.95), an energy expenditure of 281 kcal/hour and a perceptual burden of 32.5. The patient walked 682 steps, spent 16.0 minutes upright, 10.0 minutes walking and achieved 0% in moderate-to-vigorous intensity. Conclusions As concordance between physical therapist burden and patient gait performance was low in this study, future efforts to identify gait training approaches that minimise therapist burden while maximising outcomes for the patient with lateropulsion are necessary for the health of both. Implications for practice Physical therapists may consider advanced technology use such as overground robotic exoskeletons to reduce the burden during the provision of gait training for patients with lateropulsion. Gait training performance of patients with lateropulsion may vary across different gait training approaches with low correspondence to therapist burden.

Augmented reality visualization for ultrasound-guided interventions: a pilot randomized crossover trial to assess trainee performance and cognitive load

BackgroundAugmented reality (AR) technology involving head-mounted displays (HMD) represents a significant innovation in medical education, particularly for training in guided invasive procedures. Novice physicians often face challenges in simultaneously identifying anatomical landmarks and performing procedures when learning point-of-care ultrasound (POCUS). Our primary objective was to determine the effectiveness of AR in enhancing physician training for ultrasound-guided interventions using AR visual overlays. The secondary objective was to compare cognitive load between traditional ultrasound training settings and AR-assisted training settings.MethodsThis randomized crossover study, conducted from 2021 to 2022, compared performance and cognitive load of trainees attempting accurate central venous catheter (CVC) placement using an AR-HMD to display ultrasound images (AR-US), compared with standard ultrasound without visual overlay (S-US). We enrolled 47 trainees, including 22 final-year undergraduate medical students and 25 postgraduate physicians (years 1–4) from three hospitals in Taiwan. All participants had basic training in US-guided CVC placement but lacked AR-US experience. Performance and cognitive load were assessed using time measurements and NASA Task Load Index (NASA-TLX), covering the dimensions of Mental-, Physical- and Temporal Demand, and Performance, Effort and Frustration.ResultsWe found AR technology reduced the time required for critical steps in CVC placement, while minimizing users’ neck strain. Female and junior trainees using AR-US identified anatomy and localized veins faster than those using S-US. Using AR-US, female trainees significantly outperformed males in anatomical identification [mean difference (MD): -10.79 s (95% CI: -2.37 to -19.21)]. The NASA-TLX cognitive load assessment showed mental workload trending lower in all dimensions except performance while using AR-US, compared to S-US. Similarly, junior trainees’ effort- and frustration scores were lower [MD: -2.73 (95% CI: -5.04 to -0.41) and -2.41 (95% CI: -4.51 to -0.31), respectively], as were female trainees’ effort scores [MD: -3.07 (95% CI: -6.10 to -0.03)] when using AR-US, compared to S-US, whereby these differences were statistically significant.ConclusionsAR technology helped improve trainee performance and reduced cognitive load during ultrasound-guided CVC placement. These findings support the application of AR technology to enhance physician training in ultrasound-guided interventional procedures, suggesting that AR-HMDs could be a valuable tool in medical education.Trial registrationThe trial was registered with Clinicaltrials.gov on 20/09/2023 as a clinical trial, under the identifier NCT 06055400.

Analysis on pulse rate variability for pilot workload assessment based on wearable sensor

AbstractThe workload levels of pilots directly affect their flight performance and the safety of the whole flight. To explore the real‐time workload of pilots in different flight phases (takeoff, cruise, and landing), this paper leveraged National Aeronautics and Space Administration Task Load Index (NASA‐TLX), a subjective evaluation scale, and PhotoPlethysmoGraphy (PPG) signals of 21 participants using a flight simulator and a wearable sensor. First, the workloads of pilots under different phases were explored by the NASA‐TLX scales; secondly, the pulse rate variability (PRV) features were selected by variance analysis and random forest importance evaluation; finally, the performances of the k‐nearest neighbor (KNN), random forest (RF), and support vector machine (SVM) were compared for workload levels identification. It is shown that the workloads are ranked as follows: landing &gt; takeoff &gt; cruise. SDNN, CVCD, CVNNI, LF, TP, SD2, and SD2/SD1 were used as selected features with significant differences in different flight phases. In addition, machine learning models can effectively identify pilot workloads, and feature selection enhances the performance of both KNN and RF classifiers. The best identification of workload was achieved using the selected PRV features as inputs to the KNN classifier, with an average accuracy of 88.9%. Our results indicate that the KNN classifier and PRV features are suitable for identifying pilot workload. The pilot workload is highest during the landing phase, which provides a reference for flight safety management. The findings from this research could contribute to developing a robust pilot workload detection system and improve current flight operation safety regulations.

Usability of Pseudo-Haptic Feedback for Manual Precise Manipulation of Objects in Augmented Reality

Manual precise manipulation of objects is a critical skill in daily life, and Augmented Reality (AR) is increasingly used to support such tasks. In this study, we propose a system utilizing pseudo-haptic feedback to support precise manipulation for six degrees of freedom (6DOF). Two types of AR instruction interfaces were developed: Visual Deviation Instruction Interface (VDI) and Pseudo-Haptic Instruction Interface (PHI). A user study with 18 participants compared the two instruction interfaces in terms of performance and user experience. The objective measures of performance (task completion time, deviation), and the subjective measures (system usability scale, NASA Task Load Index) were collected. Results show that both instruction interfaces effectively support manual precise manipulation, achieving position deviations under 2 mm and orientation deviations under 1°. PHI outperformed VDI in speed, mental effort, physical demand, performance, perceived workload, custom user experience elements and reduction deviations of manual precise manipulation. Finally, we discuss research limitations and future directions.