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

PURPOSE

In this study, we investigate the ability of automated performance metrics (APMs) and task-evoked pupillary response (TEPR), as objective measures of surgeon performance, to distinguish varying levels of surgeon expertise during generic robotic surgical tasks. Additionally, we evaluate the association between APMs and TEPR.

METHODS

Participants completed ten tasks on a da Vinci Xi Surgical System (Intuitive Surgical, Inc.), each representing a surgical skill type: EndoWrist^® manipulation, needle targeting, suturing/knot tying, and excision/dissection. Automated performance metrics (instrument motion tracking, EndoWrist^® articulation, and system events data) and TEPR were recorded by a systems data recorder (Intuitive Surgical, Inc.) and Tobii Pro Glasses 2 (Tobii Technologies, Inc.), respectively. The Kruskal-Wallis test determined significant differences between groups of varying expertise. Spearman's rank correlation coefficient measured associations between APMs and TEPR.

RESULTS

Twenty-six participants were stratified by robotic surgical experience: novice (no prior experience; n = 9), intermediate (< 100 cases; n = 9), and experts (≥ 100 cases; n = 8). Several APMs differentiated surgeon experience including task duration (p < 0.01), time active of instruments (p < 0.03), linear velocity of instruments (p < 0.04), and angular velocity of dominant instrument (p < 0.04). Task-evoked pupillary response distinguished surgeon expertise for three out of four task types (p < 0.04). Correlation trends between APMs and TEPR revealed that expert surgeons move more slowly with high cognitive workload (ρ < - 0.60, p < 0.05), while novices move faster under the same cognitive experiences (ρ > 0.66, p < 0.05).

CONCLUSIONS

Automated performance metrics and TEPR can distinguish surgeon expertise levels during robotic surgical tasks. Furthermore, under high cognitive workload, there can be a divergence in robotic movement profiles between expertise levels.

Culture-Fair Cognitive Ability Assessment

Valid assessment with diverse populations requires tools that are not influenced by cultural elements. This study investigated the relationships between culture, information processing efficiency, and general cognitive capacities in samples of Caucasian and Mexican American college students. Consistent with the neural efficiency hypothesis, pupillary responses (indexing mental effort) and detection accuracy scores on a visual backward-masking task were both significantly related to the Wechsler Adult Intelligence Scale-Revised (WAIS-R) Full Scale scores. These measures of information processing efficiency were similar in the two groups. However, they were related only to Caucasian American, but not to a comparable sample of Mexican American, students’ WAIS-R scores. Therefore, the differential validity in prediction suggests that the WAIS-R test may contain cultural influences that reduce the validity of the WAIS-R as a measure of cognitive ability for Mexican American students. Information processing and psychophysiological approaches may be helpful in developing culture-fair cognitive ability measures.

Brief report: eye-movement patterns during an embedded figures test in children with ASD

The present study examined fixation frequency and duration during an Embedded Figures Test (EFT) in an effort to better understand the attentional and perceptual processes by which individuals with autism spectrum disorder (ASD) achieve accelerated EFT performance. In particular, we aimed to elucidate differences in the patterns of eye-movement in ASD and typically developing (TD) children, thus providing evidence relevant to the competing theories of weak central coherence (WCC) and enhanced perceptual functioning. Consistent with prior EFT studies, we found accelerated response time (RT) in children with ASD. No group differences were seen for fixation frequency, but the ASD group made significantly shorter fixations compared to the TD group. Eye-movement results indicate that RT advantage in ASD is related to both WCC and enhanced perceptual functioning.

Geomatics in injury prevention: the science, the potential and the limitations

BACKGROUND

Geomatics describes the activities involved in acquiring and managing geographical data and producing geographical information for scientific, administrative and technical endeavors. As an emerging science, geomatics has a great potential to support public health. Geomatics provides a conceptual foundation for the development of geographic information systems (GIS), computerized tools that manage and display geographical data for analytical applications. As descriptive epidemiology typically involves the examination of person, place and time in the occurrence of disease or injury, geomatics and GIS can play an important role in understanding and preventing injury.

AIM

This article provides a background to geomatics for those in the injury prevention field who are unfamiliar with spatial analysis. We hope to stimulate researchers and practitioners to begin to use geomatics to assist in the prevention of injury.

METHODS

The authors illustrate the potential benefits and limitations of geomatics in injury prevention in a non-technical way through the use of maps and analysis.

RESULTS

By analysing the location of patients treated for fall injuries in Central Toronto using GIS, some demographic and land use variables, such as household income, age, and the location of homeless shelters, were identified as explanatory factors for the spatial distribution.

CONCLUSION

By supporting novel approaches to injury prevention, geomatics has a great potential for efforts to combat the burden of injury. Despite some limitations, those with an interest in injury prevention could benefit from this science.

Identifying cognitive state from eye metrics

INTRODUCTION

This paper describes a new approach for identifying cognitive state by using information obtained only from the eye. Data are collected from cameras mounted on a lightweight headband. A set of eye metrics captures essential eye information from the raw data of pupil size and point-of-gaze. The metrics are easily calculated every second, so that the entire set of metrics can be computed in real time.

METHODS

Three studies provide empirical evidence to test whether the eye metrics are sufficient to discriminate between two different cognitive states. The first study examines the states of relaxed and engaged in the context of problem solving. The second study looks at the states of focused and distracted attention in the context of driving. The third study inspects the states of alert and fatigued in the context of visual search. Two statistical models are used to classify cognitive state for all three studies: linear discriminant function analysis and non-linear neural network analysis. Data for the models are eye metrics computed at 1-, 4-, and 10-s intervals.

RESULTS

All discriminant function analyses are statistically significant, and classification rates are high. Neural network models have equal or better performance than discriminant function models across all three studies.

DISCUSSION

The seven eye metrics successfully discriminate between the states in all studies. Models from individual participants as well as the aggregate model over all participants are successful in identifying cognitive states based on task condition. Classification rates compare favorably with similar studies.

Pupillary responses on the visual backward masking task reflect general cognitive ability

Cognitive processing efficiency requires both an ability to attend to task-relevant stimuli with quickness and accuracy, also while filtering distracting or task-irrelevant stimuli. This study investigated cognitive processing efficiency by using pupillary responses as an index of attentional allocation to relevant target and irrelevant masks on a visual backward masking task. The relationship between attentional allocation on this task and general cognitive ability on the scholastic aptitude test (SAT) was examined in college students (n=67). A principle components analysis of the pupillary response waveform isolated a late component that appeared to index the attentional demands associated with processing masks on the backward masking task. This pupillary response index of wasteful resource allocation to the mask accounted for significant variance in SAT scores over and above that accounted for by socio-economic status and target detection accuracy scores. Consistent with the neural efficiency hypothesis, individuals who allocated more resources to processing irrelevant information performed more poorly on cognitive ability tests.

A new mixed micellar preparation for oral vitamin K prophylaxis: randomised controlled comparison with an intramuscular formulation in breast fed infants

OBJECTIVE

To compare a new oral preparation of vitamin K1 (Konakion MM) containing lecithin and glycocholic acid with a standard intramuscular (IM) preparation during the first 8 weeks of life in exclusively breast fed infants.

METHODS

Infants were randomised at birth to the IM group (1 mg vitamin K) or the oral group (2 mg given at birth and repeated at 7 and 30 days of life). Prothrombin time (INR), plasma vitamin K1, and PIVKA II (undercarboxylated prothrombin) were monitored at 14, 30, and 56 days of age.

RESULTS

Seventy nine infants were randomised to the oral group and 77 to the IM group. Sixty seven infants in each group completed eight weeks of the study. Prothrombin times did not differ between the two groups. Mean (SD) plasma vitamin K1 values (in ng/ml) decreased in both groups over time, but were higher in the oral group at 14 and 56 days: 2.0 (1.6) v 1.3 (1.1) at 14 days; 0.5 (0.3) v 0.5 (0.7) at 30 days; and 0.5 (0.8) v 0.2 (0.2) at 56 days of life. PIVKA II was raised (> or = 0.1 AU/ml) in cord blood in 47% of the infants. By 14 days, only one infant in each group had a raised PIVKA II value and both of these initially had high concentrations of PIVKA II in cord blood. At 30 days, there were no raised PIVKA II values. At 56 days, there were no raised PIVKA II values in the oral group, although three infants in the IM group had raised values.

CONCLUSIONS

Plasma vitamin K concentrations were at least equal or significantly higher in babies given oral vitamin K supplements compared with IM treated babies at the time points measured. Through the first 8 weeks of life, multiple doses of the new oral preparation maintain haemostasis and vitamin K status in breast fed infants at least equal to that of the intramuscular preparation.

Improving the vitamin K status of breastfeeding infants with maternal vitamin K supplements

OBJECTIVE

To increase the phylloquinone (vitamin K1) concentration of human milk with maternal oral phylloquinone supplements such that both the phylloquinone intake of breastfed infants and their serum concentrations of phylloquinone would approach those of formula-fed infants who are known to be at much less risk for hemorrhagic disease of the newborn.

DESIGN

Two stages: stage I, longitudinal, randomized study of 6 weeks' duration; and stage II, longitudinal, randomized, double-blind, placebo-controlled study of 12 weeks' duration.

SETTING

Patients from a private pediatric practice in Madison, WI.

PATIENTS

Stage I: sequential sampling of 20 lactating mothers to determine the level of maternal supplementation needed in stage II. Ten mothers received 2.5 mg/d oral phylloquinone, and 10 mothers received 5.0 mg/d oral phylloquinone. Stage II: sequential sampling of 22 human milk-fed infants and lactating mothers. All infants received 1 mg of phylloquinone at birth. Eleven mothers received a placebo; 11 mothers received 5 mg/d phylloquinone.

MEASUREMENTS AND RESULTS

In stage I, both 2.5 and 5.0 mg/d phylloquinone significantly increased the phylloquinone content of human milk at both 2 and 6 weeks. As expected, 5.0 mg had a greater effect (mean +/- SD, 58.96 +/- 25.39 vs 27.12 +/- 12.18 ng/mL at 2 weeks). In stage II, the vitamin K-supplemented group had significantly higher maternal serum phylloquinone concentrations, higher phylloquinone milk concentrations, and higher infant plasma phylloquinone concentrations at 2, 6, and 12 weeks compared with the placebo group. At 12 weeks infant phylloquinone intakes were significantly higher for the vitamin K group than the placebo group (9.37 +/- 4.55 vs 0.15 +/- 0.07 microgram/kg per day). This corresponded to a plasma phylloquinone concentration in the vitamin K group of 2.84 +/- 3.09 vs 0.34 +/- 0.57 ng/mL in the placebo group. At 12 weeks, the prothrombin times did not differ between the groups, but the des-gamma-carboxy-prothrombin (partially carboxylated prothrombin thought to be a measure of vitamin K deficiency) was significantly elevated in the placebo group compared with the vitamin K group (1.48 +/- 1.19 vs 0.42 +/- 0.55 ng/mL).

CONCLUSION

In exclusively breastfed infants who receive intramuscular phylloquinone at birth, the vitamin K status as measured by plasma phylloquinone and des-gamma-carboxy-prothrombin concentrations is improved by maternal oral supplements of 5 mg/d phylloquinone through the first 12 weeks of life.

Perceived anxiety of pediatric patients to magnetic resonance

Magnetic resonance imaging (MRI), a nonionizing radiologic technique without known adverse physical effects, is utilized frequently in children and adolescents. The MRI technique requires prolonged immobility in a narrow, confined space, and concern has been raised regarding possible patient anxiety and noncompliance. Several reports suggest that up to 10% of adults undergoing MRI may experience anxiety and/or claustrophobia. 1 However, to our knowledge, no studies of the subjective MRI experiences of children and adolescents have been published. We report here the general characteristics of 491 consecutive Pediatric patients who were evaluated with MRI at our institution, including the experience of anxiety in 85 older children and adolescents.

Liquid feed passage route into stomach compartments, influence of abomasal infusions on plasma glucose, and supplementation of dry rations with liquid feeds from lick-wheel feeders

Passage route into stomach compartments of liquid feeds containing a marker was studied by feeding a liquid supplement and molasses from a lick-wheel feeder and by infusing the liquid supplement into the reticulorumen 30 min prior to sampling contents of the reticulorumen and abomasum and 4 h prior to sampling blood for plasma glucose. Recovery from reticulorumen and concentration of marker in abomasal ingesta gave no evidence of rumen bypass, this supported by a gross correlation of .92 between rumen ammonia nitrogen and nonprotein nitrogen intake from liquid feeds. Plasma glucose values were not different. Preinfusion and postinfusion plasma glucose values were similar for abomasal infusion of about 454 g of molasses, 20% crude protein liquid supplement, and for the basal diet. Values were lower for abomasal infusion of the 35% crude protein liquid supplement (Pro-Lix) than for the 20% crude protein liquid supplement. When complete rations containing 11.5, 13.0, and 14.5% crude protein were supplemented with either molasses or a 20% crude protein liquid supplement fed from lick-wheel feeders, intake averaged .53 and .34 kg per animal daily for the respective liquid feeds. There was no effect on milk yield, solids-corrected milk, milk fat content, protein content, solids-not-fat percent, or body weight change. There was an interaction of protein level and liquid feeds in which plasma glucose was increased by liquid feeds in higher but not in lower protein diets.