The transmission line modelling (t.l.m.) method is well established as a numerical routine for the solution of electromagnetic wave problems and electrical lumped networks. In this paper the method is adapted for the solution of dynamic mechanical systems. The method provides discrete models suitable for manipulation by digital computer and straightforward modelling of non-linearities. A complete modelling example of a bearing with non-linear friction characteristics is presented.

Purpose: The introduction of whole slide imaging and digital pathology has enabled greater scrutiny of visual search behaviors among pathologists. We aim to investigate zooming and panning behaviors, external markers of visual processing capabilities, and the changes with experience.Approaches: Twenty digitized breast core needle biopsy histopathology slides were obtained from the circulating slides from the main digital pathology trial (IRAS number: 258799). These were presented to five pathologists with varying experience (1.5 to 40 years) whose examinations were recorded. Data of visual fixations were collected using eye-tracking cameras, and the magnification data and zooming behaviors were extracted in an objective fashion by an automated algorithm. The relationship between experience and metrics was analyzed using mixedeffects regression analyses.Results: There was a significant association between experience and both reading times (p < 0.001) and a number of fixations (p < 0.001), with these relationships being inversely proportional. The greater experience was also associated with greater diagnostic accuracy (p ¼ 0.033). We found that experience was significantly associated with greater use of magnification changes (p < 0.001). Conversely, less experience showed a near significant association with the increased proportion of time spent panning (p ¼ 0.070).Conclusions: Fewer fixations needed to reach a diagnosis and quicker reading times are indicative of greater cognitive and visual processing capabilities with greater experience. These cognitive capabilities may be a prerequisite for the more frequent zooming changes that are more prevalent with increasing experience.

Objectives: The interpretation of digital breast tomosynthesis (DBT) screening examinations is a complex task for an already overstretched workforce which has the potential to increase pressure on readers leading to fatigue and patient safety issues. Studies in non-medical and medical settings have suggested that changes in blink characteristics can reflect fatigue. The purpose of this study is to investigate the use of blink characteristics as an objective marker of fatigue in readers interpreting DBT breast screening examinations. Methods: Twenty-six DBT readers involved in the UK PROSPECTS trial interpreted a test set of 40 DBT cases while being observed by an eye tracking device from November 2019 to February 2021. Raw data from the eye tracker were collected and automated processing software was used to produce eye blinking characteristics data which were analysed using multiple linear regression statistical models. Results: Of the 26 DBT readers recruited, eye tracking data from 23 participants were analysed due to missing data rendering 3 participants’ data uninterpretable. The mean reading time per DBT case was 2.81 min. There was a statistically significant increase in blinking duration of 0.38 ms/case as the reading session progressed (p < 0.0001). This was the result of a significant decrease in the number of ultra-short blinks lasting ≤50 ms (p = 0.0005) and a significant increase in longer blinks lasting 51–100 ms (p = 0.008). Conclusion Changes in blinking characteristics could serve as objective measures of reader fatigue and may prove useful in the development of DBT reading protocols. Advances in knowledge: Blink characteristics can be used as an objective measure of fatigue; however there is limited evidence of their use in radiological settings. Our study suggests that changes in blink duration and frequency could be used to monitor fatigue in DBT reading sessions.

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Digital Breast Tomosynthesis (DBT) increases breast cancer detection rates but produces a significantly greater number of images for screeners to read compared to traditional two-dimensional (2-D) mammograms. Putting screeners at risk of fatigue and therefore error in detecting cancers. The aim of this study was to explore if screeners showed differences in subjective fatigue, blink metrics and diagnostic accuracy during a DBT reading session with and without breaks. Prospective study including 45 participants from 6 different hospital sites around England between December 2020 to April 2022. Non-intrusive, screen mounted eye tracking cameras (60Hz sampling rate) were set up in the participant’s natural reading environment. Forty DBT cases were read in a random order (47.5% malignant, 12.5% benign, 40% normal). Each breast was rated as normal or benign (return to screen) or indeterminate, suspicious or highly suspicious (recall). Twenty-one participants had a break at approximately 40 minutes into the session. Participants without a break showed a significantly greater difference in subjective fatigue before and after the reporting session (44% vs 33%, p=0.037). Furthermore, those without breaks exhibited significantly greater blinks per minute (15.75 vs 13.25, p<0.001) and blink duration (milliseconds) (296 vs 286, p<0.001). There was no significant difference in overall accuracy between the cohorts (p=0.921). Blink metrics have the potential to be used in identifying early onset of fatigue during reading sessions.