Marcus Watson

GEOGRAPHICAL VARIATION IN THE ACCLIMATION RESPONSES OF DROSOPHILA TO TEMPERATURE EXTREMES

Populations may adapt to climatic stresses by nonplastic or plastic changes in stress resistance. Plastic changes include a range of different acclimation mechanisms. A few previous studies with Drosophila suggest interspecific variation in plastic responses to climatic stresses, but there is not much evidence for variation within species. Tropical and temperate populations of Drosophila melanogaster and Drosophila sirnulans were compared for plastic responses to cold and heat stress. Tropical populations tended to be less resistant to cold stress than temper- ate populations.-In contrast, D. melanogaster populations showed similar acclimation responses to cold stress following different acclimation treatments, which included keeping adults at low temperatures for a few hours or several days and culturing larvae at a low temperature. Popula- tions of D. simulans also showed similar plastic responses to cold stress after adults were acclimated at a low temperature for several days. In the heat resistance experiments, there was no evidence for population differences in acclimation response in either D. melanogaster or D. sitnulans when adults were exposed to high and low temperatures for a few days. Genetic variation for acclimation response may therefore be mainly restricted to the interspecific level, although larger experiments are required to detect small quantitative differences between popu- lations.

Designing for attention with sound: Challenges and extensions to ecological interface design

Objective: We explore whether ecological interface design (EID) principles can be applied to the design of an auditory display for anesthesia monitoring. Background: EID examples focus almost exclusively on visual displays. In the anesthesia work environment, however, auditory displays may provide better individual and team awareness of patient state. Method: Using a work domain analysis of physiological monitoring in anesthesia, we identify information to display. Using the skills, rules, and knowledge distinction we identify cognitive control needed. Using semantic mapping we map physiological variables and constraints to auditory dimensions. Results: EID principles do not address when information should be displayed and to whom. An attentional mapping stage helps to specify answers to these questions so that a workable auditory display for anesthesia monitoring is achieved. Conclusion: EID principles of representing work domain functional structure and minimizing resource-demanding cognitive control are necessary but insufficient to specify requirements for an effective auditory display. Also needed are analyses of control tasks, strategies, and the social organization of work. Such analyses are an integral part of the broader cognitive work analysis framework from which EID emerged. Application: Actual or potential uses of this research include the design of displays that support continuous peripheral awareness in collaborative multimodal work environments.

Sonification Supports Eyes-Free Respiratory Monitoring and Task Time-Sharing

Three experiments explored the effectiveness of continuous auditory displays, or sonifications, for conveying information about a simulated anesthetized patients respiration. Experiment 1 established an effective respiratory sonification. Experiment 2 showed an effect of expertise in the use of respiratory sonification and revealed that some apparent differences in sonification effectiveness could be accounted for by response bias. Experiment 3 showed that sonification helps anesthesiologists to maintain high levels of awareness of the simulated patients state while performing other tasks more effectively than when relying upon visual monitoring of the simulated patient state. Overall, sonification of patient physiology beyond traditional pulse oximetry appears to be a viable and useful adjunct to visual monitors. Actual and potential applications of this research include monitoring in a wide variety of busy critical care contexts.

Advanced Auditory Displays and Head-Mounted Displays: Advantages and Disadvantages for Monitoring by the Distracted Anesthesiologist

BACKGROUND:In a full-scale anesthesia simulator study we examined the relative effectiveness of advanced auditory displays for respiratory and blood pressure monitoring and of head-mounted displays (HMDs) as supplements to standard intraoperative monitoring. METHODS:Participants were 16 residents and attendings. While performing a reading-based distractor task, participants supervised the activities of a resident (an actor) who they were told was junior to them. If participants detected an event that could eventually harm the simulated patient, they told the resident, pressed a button on the computer screen, and/or informed a nearby experimenter. Participants completed four 22-min anesthesia scenarios. Displays were presented in a counterbalanced order that varied across participants and included: (1) Visual (visual monitor with variable-tone pulse oximetry), (2) HMD (Visual plus HMD), (3) Audio (Visual plus auditory displays for respiratory rate, tidal volume, end-tidal CO2, and noninvasive arterial blood pressure), and (4) Both (Visual plus HMD plus Audio). RESULTS:Participants detected significantly more events with Audio (mean = 90%, median = 100%, P < 0.02) and Both (mean = 92%, median = 100%, P < 0.05) but not with HMD (mean = 75%, median = 67%, ns) compared with the Visual condition (mean = 52%, median = 50%). For events detected, there was no difference in detection times across display conditions. Participants self-rated monitoring as easier in the HMD, Audio and Both conditions and their responding as faster in the HMD and Both conditions than in the Visual condition. CONCLUSIONS:Advanced auditory displays help the distracted anesthesiologist maintain peripheral awareness of a simulated patients status, whereas a HMD does not significantly improve performance. Further studies should test these findings in other intraoperative contexts.

Advanced Patient Monitoring Displays: Tools for Continuous Informing

We reviewed the use of advanced display technologies for monitoring in anesthesia. Researchers are investigating displays that integrate information and that, in some cases, also deliver the results continuously to the anesthesiologist. Integrated visual displays reveal higher-order properties of patient state and speed in responding to events, but their benefits under an intensely timeshared load is unknown. Head-mounted displays seem to shorten the time to respond to changes, but their impact on peripheral awareness and attention is unknown. Continuous auditory displays extending pulse oximetry seem to shorten response times and improve the ability to timeshare other tasks, but their integration into the already noisy operative environment still needs to be tested. We reviewed the advantages and disadvantages of the three approaches, drawing on findings from other fields, such as aviation, to suggest outcomes where there are still no results for the anesthesia context. Proving that advanced patient monitoring displays improve patient outcomes is difficult, and a more realistic goal is probably to prove that such displays lead to better situational awareness, earlier responding, and less workload, all of which keep anesthesia practice away from the outer boundaries of safe operation.

Leximancer concept mapping of patient case studies

Quantitative databases are limited to information identified as important by their creators, while databases containing natural language are limited by our ability to analyze large unstructured bodies of text. Leximancer is a tool that uses semantic mapping to develop concept maps from natural language. We have applied Leximancer to educational based pathology case notes to demonstrate how real patient records or databases of case studies could be analyzed to identify unique relationships. We then discuss how such analysis could be used to conduct quantitative analysis from databases such as the Coronary Heart Disease Database.

Monitoring with Head-Mounted Displays: Performance and Safety in a Full-Scale Simulator and Part-Task Trainer

BACKGROUND: Head-mounted displays (HMDs) can help anesthesiologists with intraoperative monitoring by keeping patients’ vital signs within view at all times, even while the anesthesiologist is busy performing procedures or unable to see the monitor. The anesthesia literature suggests that there are advantages of HMD use, but research into head-up displays in the cockpit suggests that HMDs may exacerbate inattentional blindness (a tendency for users to miss unexpected but salient events in the field of view) and may introduce perceptual issues relating to focal depth. We investigated these issues in two simulator-based experiments. METHODS: Experiment 1 investigated whether wearing a HMD would affect how quickly anesthesiologists detect events, and whether the focus setting of the HMD (near or far) makes any difference. Twelve anesthesiologists provided anesthesia in three naturalistic scenarios within a simulated operating theater environment. There were 24 different events that occurred either on the patient monitor or in the operating room. Experiment 2 investigated whether anesthesiologists physically constrained by performing a procedure would detect patient-related events faster with a HMD than without. Twelve anesthesiologists performed a complex simulated clinical task on a part-task endoscopic dexterity trainer while monitoring the simulated patient’s vital signs. All participants experienced four different events within each of two scenarios. RESULTS: Experiment 1 showed that neither wearing the HMD nor adjusting the focus setting reduced participants’ ability to detect events (the number of events detected and time to detect events). In general, participants spent more time looking toward the patient and less time toward the anesthesia machine when they wore the HMD than when they used standard monitoring alone. Participants reported that they preferred the near focus setting. Experiment 2 showed that participants detected two of four events faster with the HMD, but one event more slowly with the HMD. Participants turned to look toward the anesthesia machine significantly less often when using the HMD. When using the HMD, participants reported that they were less busy, monitoring was easier, and they believed they were faster at detecting abnormal changes. CONCLUSIONS: The HMD helped anesthesiologists detect events when physically constrained, but not when physically unconstrained. Although there was no conclusive evidence of worsened inattentional blindness, found in aviation, the perceptual properties of the HMD display appear to influence whether events are detected. Anesthesiologists wearing HMDs should self-adjust the focus to minimize eyestrain and should be aware that some changes may not attract their attention. Future areas of research include developing principles for the design of HMDs, evaluating other types of HMDs, and evaluating the HMD in clinical contexts.

Cross-Generation Effects for Cold Resistance in Tropical Populations of Drosophila-Melanogaster and Drosophila-Simulans

Cross-generation effects on the cold resistance of Drosophila melanogaster and D. simulans were investigated by exposing adults to different levels of cold stress and testing the resistance of female F1s and F2s. Maternal and paternal treatments had different effects on progeny resistance. Maternal effects were not detected for either species when progeny were held at 25-degrees-C, but were detected when progeny were acclimated at 13-degrees-C prior to testing. When dams were exposed to a non-lethal cold stress following acclimation, the cold resistance of their progeny was increased, particularly in D. simulans. Grandmaternal exposure to 13-degrees-C and a non-lethal stress led to a small decrease in the cold resistance of D. melanogaster, and a small increase in the resistance of D. simulans. When sires of D. melanogaster and D. simulans were exposed to a cold stress, the resistance of their progeny decreased when progeny were tested without acclimation at 13-degrees-C, but decreased only in D. melanogaster when progeny were acclimated. Paternal effects were smaller than maternal effects and were not evident in the F2 generation.

The Conflicting Evidence of Three-dimensional Displays in Laparoscopy: A Review of Systems Old and New.

Objective:To describe studies evaluating 3 generations of three-dimensional (3D) displays over the course of 20 years. Summary Background Data:Most previous studies have analyzed performance differences during 3D and two-dimensional (2D) laparoscopy without using appropriate controls that equated conditions in all respects except for 3D or 2D viewing. Methods:Databases search consisted of MEDLINE and PubMed. The reference lists for all relevant articles were also reviewed for additional articles. The search strategy employed the use of keywords “3D,” “Laparoscopic,” “Laparoscopy,” “Performance,” “Education,” “Learning,” and “Surgery” in appropriate combinations. Results:Our current understanding of the performance metrics between 3D and 2D laparoscopy is mostly from the research with flawed study designs. This review has been written in a qualitative style to explain in detail how prior research has underestimated the potential benefit of 3D displays and the improvements that must be made in future experiments comparing 3D and 2D displays to better determine any advantage of using one display or the other. Conclusions:Individual laparoscopic performance in 3D may be affected by a multitude of factors. It is crucial for studies to measure participant stereoscopic ability, control for system crosstalk, and use validated measures of performance.

Sources of inaccuracy in the measurement of adult patients’ resting blood pressure in clinical settings: a systematic review

Background: To interpret blood pressure (BP) data appropriately, healthcare providers need to be knowledgeable of the factors that can potentially impact the accuracy of BP measurement and contribute to variability between measurements. Methods: A systematic review of studies quantifying BP measurement inaccuracy. Medline and CINAHL databases were searched for empirical articles and systematic reviews published up to June 2015. Empirical articles were included if they reported a study that was relevant to the measurement of adult patients’ resting BP at the upper arm in a clinical setting (e.g. ward or office); identified a specific source of inaccuracy; and quantified its effect. Reference lists and reviews were searched for additional articles. Results: A total of 328 empirical studies were included. They investigated 29 potential sources of inaccuracy, categorized as relating to the patient, device, procedure or observer. Significant directional effects were found for 27; however, for some, the effects were inconsistent in direction. Compared with true resting BP, significant effects of individual sources ranged from −23.6 to +33 mmHg SBP and −14 to +23 mmHg DBP. Conclusion: A single BP value outside the expected range should be interpreted with caution and not taken as a definitive indicator of clinical deterioration. Where a measurement is abnormally high or low, further measurements should be taken and averaged. Wherever possible, BP values should be recorded graphically within ranges. This may reduce the impact of sources of inaccuracy and reduce the scope for misinterpretations based on small, likely erroneous or misleading, changes.