Experienced User Research Articles

Hand-assisted positioning and contact pressure control for motion compensated robotized transcranial magnetic stimulation

In Transcranial Magnetic Stimulation (TMS), the principle of magnetic induction is used to stimulate the brain non-invasively. Currently, robotic TMS systems are developed to guarantee precise coil placement on the head and in this way achieve the repeatability of stimulation results. However, usability concerns such as the complicated coil positioning are still unsolved for motion compensated robotized TMS. In this paper, we demonstrate the integration of a force-torque control into a robotic TMS system to improve usability, safety, and precision. We integrated a force-torque sensor between robot effector and TMS coil. Coil calibration and gravity compensation have been developed. Based on them, we have implemented hand-assisted positioning for easy and fast coil placement. Furthermore, we have enhanced the existing motion compensation algorithms with a contact pressure control. The positioning time for an experienced user decreased up to 40% with the help of hand-assisted positioning in comparison with not hand-assisted robotized positioning. It also enabled an inexperienced user to use the system safely. Integration of a force-torque control into the motion compensated robotized TMS system greatly enhances system's usability, which is a prerequisite for integration in the clinical workflow and clinical acceptance.

Étude de reproductibilité de la cotation du « Bilan 400 points », une mesure de capacité fonctionnelle de la main

ObjectivesEvaluate the inter-rater and test-retest reproducibility of the “400 Points assessment”, a measurement of the functional ability of the hand. The scale included four tests: function of the hand, prehension strengths, handling and displacement of things, and function with both hands. MethodsThirty patients with hand injuries were participated. The inter-rate agreements were examinated between three occupational therapists. The First rater was an experienced user of this instrument (observer 1), the second one was a novice user (observer 2), the last rater is a student who had never used it before (observer 3). Subjects were tested twice by the same raters independently, with 30minutes intervals between tests. Statistical analysis was done by calculating average differences and intraclass correlation coefficient. Results(i) The difference between the three raters agreements was small for the two measurements, except for function with both hands in the second period. Every intraclass correlation coefficient was higher than 0.95. (ii) Difference between the two measurements was small for every observer. These differences are not significant except for function with both hands. Intraclass correlation coefficients are all higher than 0.82 even than 0.90 for the total score. The difference between the two periods for the overall test is small, from 5% to 10% for seven patients and from 10 to 15% for two patients. Differences at two times had the same agreement for the three observers. Conclusion“400 Points assessment” is reproducible (inter-rater and test-retest reproductibility). The test “function with both hands” requires more experience of the assessment.

Simulating Knowledge Worker Adoption Rate of KMS: An Organizational Perspective

The core research issue presented in this article is to study the factors that influence the knowledge worker's adoption of Knowledge Management System (KMS). The five- step System Dynamics research methodology was followed to design and develop the Knowledge worker adoption model. This model studies the transition of a knowledge worker from a non-user to an experienced user over a fixed time frame identified. Simulation experiments were conducted show that knowledge workers respond differently as they integrate the new technology into their work pattern. The results were analyzed for the different employee categories based on their level of expertise of usageof KMS in the organization and factors such as supervision, ease of use of technology were found to affect the knowledge worker's concerns for adopting KMS in their work. The current simulation model was built using the softwareVensim® and the outcome of the study should aid administrators and policy makers to evaluate the impact ofthe identified factors on adoption of KMS.

HIFU: Definitely ready for prime time

HIFU: Definitely ready for prime time

Automatic Classification of Ground-Penetrating-Radar Signals for Railway-Ballast Assessment

The ground-penetrating radar (GPR) has been widely used in many applications. However, the processing and interpretation of the acquired signals remain challenging tasks since an experienced user is required to manage the entire operation. In this paper, we present an automatic classification system to assess railway-ballast conditions. It is based on the extraction of magnitude spectra at salient frequencies and their classification using support vector machines. The system is evaluated on real-world railway GPR data. The experimental results show that the proposed method efficiently represents the GPR signal using a small number of coefficients and achieves a high classification rate when distinguishing GPR signals reflected by ballasts of different conditions.

Object tracking with particle filtering in fluorescence microscopy images: application to the motion of neurofilaments in axons.

Neurofilaments are long flexible cytoplasmic protein polymers that are transported rapidly but intermittently along the axonal processes of nerve cells. Current methods for studying this movement involve manual tracking of fluorescently tagged neurofilament polymers in videos acquired by time-lapse fluorescence microscopy. Here, we describe an automated tracking method that uses particle filtering to implement a recursive Bayesian estimation of the filament location in successive frames of video sequences. To increase the efficiency of this approach, we take advantage of the fact that neurofilament movement is confined within the boundaries of the axon. We use piecewise cubic spline interpolation to model the path of the axon and then we use this model to limit both the orientation and location of the neurofilament in the particle tracking algorithm. Based on these two spatial constraints, we develop a prior dynamic state model that generates significantly fewer particles than generic particle filtering, and we select an adequate observation model to produce a robust tracking method. We demonstrate the efficacy and efficiency of our method by performing tracking experiments on real time-lapse image sequences of neurofilament movement, and we show that the method performs well compared to manual tracking by an experienced user. This spatially constrained particle filtering approach should also be applicable to the movement of other axonally transported cargoes.

The influence of head and neck position on ventilation with the i-gel airway in paralysed, anaesthetised patients

We hypothesised that head and neck position could affect the effectiveness of ventilation with the i-gel airway. To test this hypothesis, we investigated the influence of different head and neck positions on oropharyngeal sealing pressures and ventilation scores during ventilation with i-gel. A single, experienced supraglottic airway device user inserted the i-gel in 20 paralysed, anaesthetised patients who were scheduled for oral surgery. Oropharyngeal leak pressures and ventilation scores were measured with the head and neck in the neutral position, flexed, extended or rotated to the right. Ventilation was scored from 0 to 3 based on three criteria (no leakage with an airway pressure of 15 cmH2O, bilateral chest excursion and a square wave capnogram; each item scoring 0 or 1 point). Compared with the neutral position (25.8 ± 5.2 cmH2O), oropharyngeal leak pressure was significantly higher with flexion (28.5 ± 3.4 cmH2O, P=0.015) and lower with extension (23.0 ± 4.2 cmH2O, P=0.015), but similar with rotation (26.7 ± 5.1 cmH2O, P=0.667). Flexion of the head and neck [2 (1-3)] adversely affected the ventilation score compared with the neutral position [3 (2-3), P=0.004]. Effective ventilation with an i-gel can be performed in patients in whom the head and neck is extended or rotated, whereas flexion of the head and neck adversely affects ventilation. Clinically, flexion of the head and neck should be avoided during ventilation with the i-gel.

Questioning the relations between biography, theory and power in biographical teaching methods: a dialogue

This paper is structured around a dialogue between Hazel Wright, who is an experienced user and advocate of biographical teaching methods, and Paul Ashwin, who has some doubts about their benefits. A statement from Wright about the potential of biographical teaching methods is countered by Ashwin, who poses three challenges related to biographical teaching methods: the forms of biography that are legitimate; students’ relations to theory; and the impact of power relations. Wright responds to these by drawing on specific teaching–learning moments and the paper closes with an invitation to the reader to decide their position on the potential benefits and limitations of biographical teaching.

Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units Guidance Manual, Toolkit User's Guide and Visual-Graphic Tools

Quantitative Tools to Determine the Expected Performance of Wastewater Soil Treatment Units Guidance Manual, Toolkit User's Guide and Visual-Graphic Tools

Effects of Head-Neck Extension on Abnormality of Laryngeal Mask Airway Function Resulting From Opening the Mouth

This study investigated the effects of head-neck extension on abnormalities of laryngeal mask airway (LMA) function resulting from opening the mouth. A single, experienced LMA user inserted the LMA in 15 patients scheduled for elective oral surgery. Oropharyngeal leak pressure and intracuff pressure were sequentially documented in 5 mouth conditions in order (0 minutes, mouth closed plus 0° extension; 3 minutes, mouth open plus 0° extension; 6 minutes, mouth open plus 15° extension; 9 minutes, mouth open plus 30° extension; and 12 minutes, mouth open plus 45° extension). Oropharyngeal leak pressures with the mouth open plus 0° extension (30.7 ± 5.6 cm H(2)O, P < .001), mouth open plus 15° extension (29.1 ± 6.8 cm H(2)O, P < .001), and mouth open plus 30° extension (25.7 ± 6.1 cm H(2)O, P < .001) were significantly higher than with the mouth closed plus 0° extension (19.7 ± 2.8 cm H(2)O). Compared with the position with the mouth closed plus 0° extension (60.0 ± 0 cm H(2)O), intracuff pressures were also higher with the mouth open plus 0° extension (84.5 ± 14.1 cm H(2)O, P < .001), mouth open plus 15° extension (77.4 ± 11.0 cm H(2)O, P < .001), and mouth open plus 30° extension (73.6 ± 9.6 cm H(2)O, P < .001). Both measurement values returned to control levels when the position with the mouth open plus 45° extension was assumed (oropharyngeal leak pressure, 64.5 ± 6.5 cm H(2)O [P = .212]; intracuff pressure, 20.2 ± 4.9 cm H(2)O [P = .969]). In procedures requiring the patient to have an open mouth under general anesthesia using LMA, 45° head-neck extension achieves acceptable airway conditions.

Evaluation of Retroreflectivity Measurement Techniques for Profiled and Rumble Stripe Pavement Markings

The objectives of this research were to evaluate the influence of stepping distance on average, dry retroreflectivity measurements of profiled and rumble stripe pavement markings through the use of a portable (handheld) retroreflectometer and to compare these measurements with ones made with a mobile retroreflectometer. The retroreflectivity of flat, profiled, and rumble stripe thermoplastic pavement markings was evaluated by several means with the use of multiple handheld retroreflectometers and a mobile retroreflectometer. Stepping distance was found to have no practical influence on averaged retroreflectivity measurements of evaluated marking types when measured in accordance with ASTM E 1710-05. The addition of an extended base on the handheld retroreflectometer, the hand-leveling of the device, or both were suitable ways to maintain the retroreflectometer in the plane defined by the tops of the pavement marking profiles for proper measurement. The vertical structure of the profiled and rumble stripe pavement markings did not increase the dry retroreflectivity measurements of the markings. The flat segments between the depressions of the rumble stripe pavement marking were found to produce the highest retroreflectivity readings of any part of the rumble stripe. A properly calibrated, mobile retroreflectometer operated by an experienced user gave dry retroreflectivity measurements that were not practically different from those obtained with a handheld retroreflectometer in accordance with ASTM E 1710-05. These findings validated the capability of the handheld retroreflectometer to accurately measure profiled and rumble stripe pavement markings.

Tools to aid the selection of ideal attribute parameter values

In a survey of Landmark, Paradigm, Schlumberger, and TerraSpark commercial products, the median number of parameters per volume process (such as attributes, or smoothing processes) was two (Figure 1a), with some volume processes having as many as 18 parameters. Each parameter used to control a volume process represents an added dimension to the parameter space of that process. With many parameters, evaluating that parameter space to find the best combination of parameters for a given data set can be quite time-consuming. Selecting the best parameter values can be daunting for an experienced user and an effective “barrier to entry” for a potential new user, causing them to not even try and instead move on to another type of technique.

Capturing expert knowledge of mesh refinement in numerical methods of impact analysis by means of genetic programming

The mesh refinement decisions of an experienced user of high-velocity impact numerical approximation finite differences computations are discovered as a set of comprehensible rules by means of Genetic Programming. These rules that could automatically trigger adaptive mesh refinement to mimic the expert user, detect mesh cells that require refinement by evolving a formula involving cell quantities such as material densities. Various cell variable combinations are investigated in order to identify the optimal ones for indicating mesh refinement. A high-velocity impact phenomena example of a tungsten ball that strikes a steel plate illustrates this methodology.

Seizure detection using digital trend analysis: Factors affecting utility

EEG monitoring is important for the early detection of seizures during the course of critical illness. However, the logistics of real time EEG interpretation is challenging for the neurophysiology and critical care medicine teams. This study evaluated factors affecting the utility of digital trend analysis (DTA) for rapid seizure identification in children. digital EEG files of seizures in critically ill children were retrieved for DTA. The envelop trend (ET) and compressed spectral array (CSA) were applied to the raw EEG data and presented to an experienced and inexperienced user for interpretation who were blinded to conventional EEG findings. The EEG findings with and without presence of seizures and features of seizures were analyzed. we found that a number of factors affected accurate seizure detection including factors related to interpreter's experiences, display size and type of DTA methods used for analysis in addition to baseline EEG findings. ET was more dependent on user experience, furthermore, display size and multimodal DTA application (CSA and ET combined) increased the sensitivity of seizure detection for the experienced user compared to inexperience users. The artifacts were reported as seizures regardless of experience without presence of conventional EEG recording. The maximum spike amplitude, seizure duration, and seizure frequency were other important determinants for accuracy. Electrographic seizures with shorter duration were better detected by ET, and the maximum spike amplitude was important for both the ET and CSA. Repetitive seizures are readily detected by both digital trending methods. Artifacts may be reported as seizures regardless of experience if conventional EEG recording is not available for the interpretation. DTA applied to the raw EEG data does produce a graphic display that facilitates identification of seizures. The actual characteristics of the electrographic seizure may predict which DTA method is better and the overall accuracy of seizure detection may increase when multimodal trending is used simultaneously. Application of DTA alone with display of conventional EEG is beneficial for rapid interpretation of EEG findings regardless of experience.

Optimal Degree of Mouth Opening for Laryngeal Mask Airway Function During Oral Surgery

This study was performed to determine the optimal degree of mouth opening in anesthetized patients requiring laryngeal mask airway (LMA) during oral surgery. A single, experienced LMA user inserted the LMA in 15 patients who were scheduled for elective oral surgery. Oropharyngeal leak pressure, intracuff pressure, and fiberoptic assessment of the LMA position were sequentially documented in 5 mouth conditions-opening of 1.4 (neutral position), 2, 3, 4, and 5 cm-and any resulting ventilatory difficulties were recorded. Oropharyngeal leak pressure with the mouth open 4 cm (21.8 ± 3.2 cm H(2)O, P = .025) and 5 cm (27.3 ± 7.2 cm H(2)O, P < .001) was significantly higher than in the neutral position (18.1 ± 1.5 cm H(2)O), as was intracuff pressure (neutral position, 60.0 ± 0 cm H(2)O; 4 cm, 72.6 ± 5.1 cm H(2)O [P < .001]; and 5 cm, 86.9 ± 14.4 cm H(2)O [P < .001]). LMA position, observed by fiberoptic bronchoscopy, was unchanged by mouth opening, being similar in the 5 mouth conditions (P = .999). In addition, ventilation difficulties (abnormal capnograph curves or inadequate tidal volume) occurred in 2 of 15 patients (13%) and 7 of 15 patients (53%) (P < .001) with the mouth opening of 4 and 5 cm, respectively. This study showed that a mouth opening over 4 cm led to substantial increases in oropharyngeal leak pressure and intracuff pressure of the LMA, warranting caution, because gastric insufflation, sore throat, and ventilation difficulties may occur. A mouth opening of 3 cm achieves acceptable airway conditions for anesthetized patients requiring LMA.

Narrow-Band Imaging Flexible Cystoscopy: A New User's Experience

We and others have demonstrated previously an improved detection rate for bladder cancer recurrences with narrow-band imaging (NBI) flexible cystoscopy when compared with conventional white-light imaging (WLI) flexible cystoscopy. We investigated whether a "new user" of NBI flexible cystoscopy, previously unfamiliar with this technique, could reproduce these results. The same protocol from our previous study was used by a new user (ZHS) for this second study at The Queen Elizabeth Hospital, Birmingham, United Kingdom. NBI flexible cystoscopy was performed on 23 patients with known recurrences of urothelial cancer (UC) of the bladder after initial conventional WLI flexible cystoscopy with the same switchable Olympus Lucera sequential red/green/blue instrument. NBI detected 15 additional UCs in 8 of the 23 (35%) patients: Six of these patients had one additional UC, one had four additional UCs, and one had five additional UCs when compared with WLI, with a mean of 0.65 additional UCs per patient (standard deviation 1.30; Wilcoxon P = 0.01). When this second series is compared with our first published series, there is no statistical evidence that the excess number of UCs detected by NBI is different (Wilcoxon [unpaired] signed-rank test P = 0.74), which suggests that there is no difference between a new user and an experienced user in the application of NBI. We and others continue to demonstrate a significantly improved detection rate of bladder UCs with NBI cystoscopy when compared with conventional WLI cystoscopy, even for new users previously unfamiliar with this technology.

Training needs and preferences of adult public library clients in the use of online resources

This article presents the results of a study into the provision of Internet training for adult public library clients. The study, which was completed in 2008, forms part of a larger investigation into the characteristics, preferences and needs of adult public library clients in New South Wales. The aim of this section of the investigation is to gain an understanding of client needs and preferences when being trained in the use of online resources in order to assist public library staff in providing relevant guidance and instruction to the community. The research takes the form of a multiple exploratory case study based on naturalistic inquiry, using grounded theory as an operational characteristic. Twenty-four public library clients were interviewed to gain an understanding of client needs in an online environment. The study identifes two main approaches to face-to-face training on Internet resources, client preferences for informal and formal tuition depending on their level of expertise. With the study indicating that computers inspire mixed feelings for the less experienced user, it is important to establish training courses tailored to specific needs to ensure the development of confidence in the use of online resources.

A scale based trust model for multi-context environments

When interactions among users of a system have to take place, for example, over the internet, establishing trust relationships among these users becomes crucial. However, the way this trust is established depends to a certain extent on the context where the interactions take place. Most of the time, trust is encoded as a numerical value that might not be very meaningful for a not very experienced user. In this paper we propose a model that takes into account the semantic and the computational sides of trust. This avoids users having to deal directly with the computational side; they instead deal with meaningful labels such as Bad or Good in a given context.

The Influence of Mouth Opening on Oropharyngeal Leak Pressure, Intracuff Pressure, and Cuff Position With the Laryngeal Mask Airway

The aim of this study was to investigate the influence of mouth opening on oropharyngeal leak pressure, intracuff pressure, and cuff position of the laryngeal mask airway (LMA). Fifteen patients who were scheduled for elective oral surgery were recruited into this study. A single, experienced LMA user inserted the LMA according to the manufacturer's recommended technique. Oropharyngeal leak pressure, intracuff pressure, and fiberoptic assessment of the LMA position were documented under 3 mouth conditions: neutral position (1.4-cm distance between upper and lower incisors), mouth open (5- to 6-cm distance between upper and lower incisors), and return to the neutral position. Any ventilation difficulties under the 3 mouth conditions were recorded. Oropharyngeal leak pressure with the mouth open was higher than in the neutral position (P < .001). Compared with the neutral position, intracuff pressure was also higher with the mouth open (P < .001). Both measurement values returned to control levels when the neutral position was once again assumed. The LMA position observed by fiberoptic bronchoscopy was unchanged by mouth opening and was similar in the 3 mouth conditions (P = .998). Although ventilatory difficulties occurred after mouth opening in 8 of 15 patients (P < .001), it did not occur when the neutral position was reassumed. This study showed that mouth opening led to substantial increases in oropharyngeal leak pressure and intracuff pressure of the LMA, warranting caution because gastric insufflation, sore throat, and ventilation difficulties may occur.

Analyzer allows testing of polar response patterns of directional hearing aids

Analyzer allows testing of polar response patterns of directional hearing aids