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Though now seen everywhere in the hospital and operating theater, there was a time when surgeons used no hand protection. In the late 19th century, however, as the science of bacteriology became more advanced, surgical glove usage spurred. Today, gloves serve an extremely important role, helping to maintain the sterile field and protect hospital staff from the transfer of bloodborne pathogens. Since they are so valuable, it is equally important that gloves fit properly as to not be detrimental to the surgeon. Gloves that are too tight increase fatigue rate and decrease fine finger dexterity. Gloves that are too loose can reduce tactile sensitivity caused by bunching of material at the fingers. Traditionally, the larger of measurement of hand circumference and hand length are used to determine glove size, but most select a size based on comfort of fit. To assist manufacturers with creating certain sizes, anthropometry is often used. Anthropometry is the study of the physical measures of the human body. Human-factors engineering is the science of applying anthropometric information to the design of devices intended for human use. In this study, two anthropometric databases, studies by Greiner and Pheasant, were utilized to obtain hand measurements representative of the general population, due to the population studied. For this study, 59 general surgeons (51 male, 8 female) were invited on separate dates to the Medtronic Minimally Invasive Therapies Group in North Haven, CT for Voice of Customer laboratories. While there, they completed surveys where they listed their preferred glove size, double gloving sizes, dominant hand, etc. In addition, the following six measurements were taken: hand circumference, maximum grip diameter, Digit 1 (D1) length, Digit 2 (D2) link length, Distance from D2 Metacarpo-phalangeal (MCP) to Distal Interphalangeal (DIP) joint, and D2 distal phalanx length (extrapolated). These measurements were averaged and compared to the numbers reported in the Greiner and Pheasant studies for analysis using a novel Microsoft Excel tool. Commonly used laparoscopic staplers were also measured to assess ergonomic usability amongst the surgeon population. Male surgeons had statistically significantly larger hands than female surgeons with respect to all measurements taken. Compared to men of the general population, male surgeons had significantly smaller grip diameter, D2 link length, yet a greater D1 Length. Compared to women of the general population, female surgeons had a greater hand circumference, yet smaller D2 link length. All other measurements recorded were statistically equivalent. In general, surgeons seem to select a preferred glove size based on their hand circumference (Pearson’s Correlation 0.799, R2 63.9%), followed by D2 Link Length (Pearson’s Correlation 0.631, R2 39.9%). The median glove size for male surgeons was 7.5 (0.50) and 6.0 (0.25) for female surgeons (p > 0.001). To evaluate the ergonomic usability of laparoscopic staplers, the measurement “Distance from D2 MCP to DIP joint” was developed internally to roughly assess effective trigger distance, where larger lengths would force the user to adjust their hand position. The handles of two commonly used laparoscopic staplers were measured to determine what proportion of the surgeon population could use them effectively. Based on these measurements, for the Medtronic Endo GIA™ Ultra Stapler, nearly all male surgeons and 99.8% of female surgeons could use it ergonomically. For the Ethicon ECHELON FLEX™ ENDOPATH® Stapler, only 78.2% of male surgeons and 30.9% of female surgeons could use it ergonomically. This study demonstrated that there exists a large amount of variability between each part of the hand based on the different measurements. Therefore, to best assure proper fitting gloves for the majority of users, a two metric system involving hand circumference and finger length would be useful to accommodate the inherent variability of the hand. With respect to laparoscopic stapling platforms, this study demonstrated that the instruments are simply too large to be used ergonomically by a large portion of the intended audience. Medical device manufacturers should look to create an adjustable handle such that the trigger distance can be manipulated to fit the needs of those surgeons with smaller hands.

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This dissertation explores patient trust in their physician and its impact on telemedicine. Telemedicine is using any technology to remotely communicate with a healthcare professional. The first study explores patient trust in their physician by validating the Wake Forest Trust in Physician scale for use in telemedicine research. The original (TIP) scale consists of 10 items and measures four of the five dimensions of trust: Fidelity, Competence, Honesty, and Global Trust. The final validated scale for telemedicine use (T-TIP) consisted of 12 items measuring three subscales: trustworthiness, interpersonal skills, and confidentiality. Study two explores the relationship between patient trust and delivery mode (telemedicine versus traditional interactions). The results from Study 2 indicate that patients trust their physician more in the telemedicine interaction than in the traditional interaction. There was also an effect of location, ethnicity, and frequency of doctor visits on patient trust. Study three delves further into the relationship between patient trust and telemedicine by examining the impact of communication mode on patient trust. Additionally, study three explores the relationship between usability and trust. There was no difference in patient trust scores between text and verbal communication. However, study three did find that as perceived usability of the interface increases, patient trust in their physician also increases. Also, this study found that the text interface had a higher fixation rate and shorter fixation duration than the video interface, indicating that the text interface had less cognitive load. These studies not only provide a tool for measuring patient trust in their telemedicine physician but also demonstrate that there is an impact of patient trust on telemedicine. The fact that patient trust in their physician is higher in telemedicine means that telemedicine could be used to increase patient participation in their own healthcare. Additionally, the relationship between usability and patient trust could be used to increase telemedicine use.

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Decades of visual attention research have predominantly used pictorial search paradigms that cue participants with the exact perceptual details of the target. However, in everyday life, people often search for categories rather than specific items (i.e., any pen rather than a specific pen). To study visual attention in a more realistic context, researchers can use categorical search paradigms that cue participants with text indicating the target category. In these instances, one must rely on long-term memory to retrieve categorical features of the target. Both experiments in this study were a reanalysis of experiments previously designed and collected by Schmidt and colleagues at Stony Brook University. In Experiment One, participants completed a pictorial or categorical search. Eye movements were used to assess search performance and electrophysiological data were assessed in response to the target cue and RI before search to evaluate the encoding and maintenance of the target. Although participants in the categorical condition were slower and exhibited weaker guidance, as measured by initial saccade direction (to the target, strong; to a distractor, weak), no differences in power or synchronous activity were observed when compared across target cue types. However, when the data were separated by guidance (strong or weak), categorical cues produced significantly more frontal-posterior theta synchrony before good guidance trials compared to bad guidance trials. In Experiment Two, participants were given categorical and specific text cues (i.e., the text always corresponded to a single target item). Specific text cues were expected to behave similarly to pictorial cues because participants knew the exact target features. Whereas specific text cues resulted in superior search performance across several measures, minimal neural differences were observed. The results from Experiment One implicate frontal-posterior theta synchrony as a potential neural marker of categorical information used to direct attention during visual.

Driving technology has progressed significantly since the introduction of anti-lock braking and cruise control decades ago. Current driver assist features can alert drivers of oncoming vehicles and even take control to keep the vehicle centered within its lane. The level of trust that people place in automation can impact how they monitor and accept these automated systems. Previous research has shown several performance outcomes associated with improper calibrations of trust in automation. However, there is still a need to examine trust in the context of advanced driving technologies. Research has yet to sufficiently investigate factors influencing trust in assistive driving features. The current study was designed to examine whether changes to the driving environment might influence levels of trust in various driver assist features. In addition, this study sought to evaluate if individual characteristics might also influence automation trust. A sample of 166 participants completed a series of hypothetical driving vignettes describing both high and low complexity environments using five different driver assist features. It was hypothesized that trust in driving technologies would be related to scenario complexity, and that trust would vary across driving features (forward collision warning, cruise control, lane centering assist, adaptive cruise/traffic jam assist, and fully automated driving). Results showed that trust was significantly higher in low complexity than in high complexity scenarios. Furthermore, trust significantly varied across the five driver assist features. Findings also revealed that propensity to trust technology moderated the relationship between trust and driving feature manipulations. Similarly, dispositional trust in three of the five unique driving feature moderated the relationship between trust and scenario complexity. These findings have implications for the design and acceptance of autonomous systems, especially automated/assistive driving technologies, as well as other remotely operated vehicles.

A significant amount of research has investigated the underlying neural mechanisms that enable the direction of attention throughout a search array. The biased competition model (Desimone & Duncan, 1995) proposes that an attentional template (the neural instantiation of the search target) is created when the target representation in visual working memory (VWM) is communicated to frontal regions which then bias early visual areas to attend to target features. Despite this, much of the current work focuses solely on the target representation in VWM, which is only one small part of the attentional template according to biased competition. Thus, I used functional connectivity analyses, to examine theta-gamma coupling across the brain, to validate the biased competition model and add to recent work that focuses exclusively on VWM. My results show that frontal to posterior theta-gamma phase-amplitude coupling is a measure of the attentional template. Greater phase-amplitude coupling was consistently observed on trials in which attention, as measured by early search eye movements, was directed towards the target rather than a distractor and was associated with superior target recognition. These findings demonstrate that frontal to posterior biasing of early visual areas is a critical neural mechanism of the attentional template.

Older adults tend to under-utilize digital technology and online services that can yield substantial benefits to their health and wellbeing. Addressing this problem requires determining robust and consistent predictors of older adults' technology use. Also, few studies have examined older adults who are elite users of digital technology, who may provide insights into how individuals can prepare to become competent users of future technologies as they age. To address these gaps in the technology and aging literature, this dissertation offers (1) large-scale machine learning analyses, (2) longitudinal perspectives, (3) age group comparisons across the adult life span, (4) the novel recruitment of elite, older users of digital technology, and (5) the development and validation of a technology use scale focused on current innovations. In Study 1, data from the Health and Retirement Study were used. Machine learning classified Internet users versus non-users with an accuracy of ~80%. Across a 14-year span, results largely supported current models of aging and technology use. Age, cognition, and socioeconomics emerged as the most robust and consistent predictors of Internet use from competition with hundreds of variables. In Study 2, the outcome variable was expanded to include nine domains of technology use. Elite, older users exhibited many markers of successful aging, including higher levels of cognition, socioeconomics, and self-efficacy. Across studies, results suggested that skills needed to engage with technology at a basic level differ slightly from those needed to reach higher levels of technology use. Specifically, poor episodic long-term memory may pose a barrier to basic technology use among older adults (e.g., assessing the Internet), while better short-term memory is required to achieve elite-level technology use. These results highlight the potential value of exposure to new technology at a younger age – when there are fewer barriers of entry (e.g., cognitive limitations) and a foundation of technology use principles can be developed and built upon across adulthood.

Emotional design elements have recently been added to the research in cognitive load and multimedia learning (Um et al., 2012). One aspect of eliciting positive emotions is to use anthropomorphic design, which has been found to increase learning performance (Um et al., 2012; Plass et al., 2014; Park et al., 2015; Schneider et al., 2018). The current research aimed to investigate three design factors in three studies: anthropomorphism in verbal and visual design, single-frame or multi-frame illustrations, and realism of the anthropomorphic visual design. The first study confirmed that the anthropomorphic verbal and visual materials were perceived as anthropomorphic by the target population. In the second and third study, college students were tested on their learning performance, affective status, intrinsic motivation, metacognitive abilities, and cognitive load levels. The second study investigated whether learning from single-frame or multi-frame illustrations along with verbal presentation of information would impact learning performance, cognitive load, metacognition, affective and motivational experiences. The role of spatial ability was also considered. Results indicated no significant differences among the groups. However, higher spatial ability resulted in higher intrinsic motivation for individuals studying with single-frame but not multi-frame illustrations. Additionally, lower spatial ability led to higher metacognition. In the third study, realism (no anthropomorphism, low fidelity, and high fidelity) of the humanlike visual illustrations and anthropomorphic language were studied. College students' learning performances were measured by comprehension and transfer tests, and intrinsic motivation, affect, and cognitive load levels were measured by self-report measurements. Overall, it was found that the humanlike visual design and the degree of fidelity of the visual design did not impact learning performance, affective status, and motivation. However, the number of interesting details (seductive details) remembered about the anthropomorphic design elements mediated the relationship between the type of design and learning performance. Using anthropomorphic language along with realistic illustrations resulted in higher seductive details recall performance, which in turn, predicted higher learning performance on both transfer and comprehension tests. Results were discussed considering Cognitive Load Theory and Cognitive-Affective Theory of Learning with Media.