73 research outputs found
Using eye gaze in intelligent interactive imaging training
Medical imaging, particularly in breast cancer screening, requires very skilled interpretation only carried out by specially trained radiologists. A key issue is how to train such skilled behaviour? Recent changes to breast imaging has seen the introduction of high resolution digital imaging which facilitates intelligent interactive training. It has also enabled potential computer aided detection of abnormalities. However, this also tends to increase false positive cancer detections. A series of experiments are reported which examine the role of eye gaze and expertise in inspecting these images. It is proposed that current training approaches could be augmented by including aspects of the eye gaze behaviour of expert screening radiologists together with computer aided detection in new practical interactive training systems
How much is enough? Factors affecting the optimal interpretation of breast screening mammograms
PERFORMS (Personal Performance in Mammographic Screening), a self-assessment scheme for film-readers is
undertaken as an educational tool by mammographers reading breast-screening films in the UK. The scheme has been
running as a bi-annual exercise since its inception in 1991. In addition to completing the scheme each year the majority
of film-readers also choose to complete a questionnaire, administered as part of the scheme, indicating key aspects of
their every-day reading practice. These key aspects include, volume of cases read per week, time-on-task reading
screening films, incidence and time of break periods as well as typical number of film-reading sessions per week.
Previous recommendations on best screening practice (significantly the optimum time on task) were considered in the
light of these film-readers’ self-reports on a current PERFORMS case set.
In addition we looked at performance accuracy of over 450 film-readers reading PERFORMS cases (60 difficult
mammographic cases). Performance on measures akin to True Positive (Correct Recall Percentages) and True Negative
(Correct Return to Screen Percentages) decisions were investigated. Data presented demonstrate that individual
behaviours in real life screening, for the interpretation of mammographic cases, affect film-reading accuracy on a test
set of mammograms for specificity and sensitivity (namely volume of cases read per week and film-reading
experience). The consequences for best screening practice, in real life, are considered
Detection of terrorist threats in air passenger luggage: expertise development
Currently, detecting potential threats in air passenger baggage heavily depends on the human examination of X-ray images of individual luggage items. In order to improve the performance of airport security personnel in searching images of air passenger luggage it is important first to understand fully the requirements of the demanding task. Here, an experiment is reported where eye movements of naive observers and screeners were recorded when they searched 30 X-ray images of air passenger luggage for potential terrorist threat items such as guns, knives and improvised explosive devices. Compared with novices, the advantages of the screeners were speed and accuracy in detecting threats. Eye position data revealed that screeners were faster to fixate on target areas and once they fixated on targets their hit rate was significantly higher. Most of the lEDs were missed by both naive observers and screeners due to interpretation errors which indicated the importance of training. Stimulus salience at the first fixation locations of naive observers and screeners was compared to investigate expertise development. It was found that experience did not change attention preference on stimuli properties at the beginning of the observers visual search. The implications and further studies are discussed
Direct gaze based environmental controls
Living in modern times, people at home are greatly enjoying the convenience brought about by advanced technologies. With steadily increased home automation applications, it is becoming more and more popular for individuals to use one central control interface to set up and operate of all the audio, video and many household appliances in a home. However, such interfaces often are too complicated for people with a disability to operate. However, the technology has long been available to achieve Environmental Control (EC) for disabled people with limited mobility, which then helps them live with more independence.
This paper presents a specially designed EC system for use by people who have lost significant mobility but who have good control of their eye movements. Through attention responsive technology, a user will be able to perform either simple or complex operations of any electrical household appliance by directly gazing at it
Exploring eye responsive control - from a head mounted to a remote system
The Attention Responsive Technology (ART) system is designed to enable control of the environment by individuals for whom movement is difficult or undesirable. This paper reports additional development of the ART system through replacing its initial head-mounted eye-tracking technology with a remotely mounted tracking system. The new system can release the user from the need to wear any head-mounted equipment, thus improving user comfort and acceptability. Instead, eye tracking cameras and the scene camera are situated in a fixed position some small distance from the user; these then allow tracking of the user’s eye gaze and field of view, respectively. This system would suit many situations in which the user remains seated, for example, in a wheelchair or before a workstation onto which the cameras can be mounted
The implementation of an AR (augmented reality) approach to support mammographic interpretation training - an initial feasibility study
Appropriate feedback plays an important role in optimising mammographic interpretation training whilst also ensuring good interpretation performance. The traditional keyboard, mouse and workstation technical approach has a critical limitation in providing supplementary image-related information and providing complex feedback in real time. Augmented Reality (AR) provides a possible superior approach in this situation, as feedback can be provided directly overlaying the displayed mammographic images so making a generic approach which can also be vendor neutral. In this study, radiological feedback was dynamically remapped virtually into the real world, using perspective transformation, in order to provide a richer user experience in mammographic interpretation training. This is an initial attempt of an AR approach to dynamically superimpose pre-defined feedback information of a DICOM image on top of a radiologist’s view, whilst the radiologist is examining images on a clinical workstation. The study demonstrates the feasibility of the approach, although there are limitations on interactive operations which are due to the hardware used. The results of this fully functional approach provide appropriate feedback/image correspondence in a simulated mammographic interpretation environment. Thus, it is argued that employing AR is a feasible way to provide rich feedback in the delivery of mammographic interpretation training
Detection of terrorist threats in air passenger luggage: expertise development
Currently, detecting potential threats in air
passenger baggage heavily depends on the human
examination of X-ray images of individual luggage items. In
order to improve the performance of airport security
personnel in searching images of air passenger luggage it is
important first to understand fully the requirements of the
demanding task. Here, an experiment is reported where eye
movements of naive observers and screeners were recorded
when they searched 30 X-ray images of air passenger
luggage for potential terrorist threat items such as guns,
knives and improvised explosive devices. Compared with
novices, the advantages of the screeners were speed and
accuracy in detecting threats. Eye position data revealed that
screeners were faster to fixate on target areas and once they
fixated on targets their hit rate was significantly higher. Most
of the IEDs were missed by both naive observers and
screeners due to interpretation errors which indicated the
importance of training. Stimulus salience at the first fixation
locations of naive observers and screeners was compared to
investigate expertise development. It was found that
experience did not change attention preference on stimuli
properties at the beginning of the observers visual search.
The implications and further studies are discussed
A new gaze-based interface for environmental control
This paper describes a new control system interface which utilises
the user’s eye gaze to enable severely disabled individuals control electronic
devices easily. The system is based upon a novel human computer interface,
which facilitates simple control of electronic devices by predicting and
responding to the user’s possible intentions, based intuitively upon their point
of gaze. The interface responds by automatically pre-selecting and offering only
those controls appropriate to the specific device that the user looks at, in a
simple and accessible manner. It therefore affords the user conscious choice of
the appropriate range of control actions required, which may be executed by
simple means and without the need to navigate manually through potentially
complex control menus to reach them. Two systems using the head-mounted
and the remote eye tracker respectively are introduced, compared and evaluated
in this paper
Mammographic interpretation training: how useful is handheld technology?
In the UK a national self-assessment scheme (PERFORMS) for mammographers is undertaken as part of the National
Health Search Breast Screening Programme. Where appropriate, further training is suggested to improve performance.
Ideally, such training would be on-demand; that is whenever and wherever an individual decides to undertake it. To use
a portable device for such a purpose would be attractive on many levels. However, it is not known whether handheld
technology can be used effectively for viewing mammographic images. Previous studies indicate the potential for
viewing medical images with fairly low spatial resolution (e.g. CT, MRI) on PDAs. In this study, we set out to
investigate factors that might affect the feasibility of using PDAs as a training technology for examining large, high
resolution mammographic images. Two studies are reported: 20 mammographers examined a series of mammograms
presented on a PDA, specifying the location of any abnormality. Secondly, a group of technologists examined a series of
mammograms presented at different sizes and resolutions to mimic presentation on a PDA and their eye movements were
recorded. The results indicate the potential for using PDAs to show such large, high resolution images if suitable
Human-computer Interaction (HCI) techniques are employed
Mammography workstation design: effect on mammographer behaviour and the risk of musculoskeletal disorders
In the UK Breast Screening Programme there is a growing transition from film to digital mammography, and
consequently a change in mammography workstation ergonomics. This paper investigates the effect of the change for
radiologists including their comfort, likelihood of developing musculoskeletal disorders (MSD’s), and work practices.
Three workstations types were investigated: one with all film mammograms; one with digital mammograms alongside
film mammograms from the previous screening round, and one with digital mammograms alongside digitised film
mammograms from the previous screening round. Mammographers were video-taped whilst conducting work sessions at
each of the workstations. Event based Rapid Upper Limb Assessment (RULA) postural analysis showed no overall
increase in MSD risk level in the switch from the film to digital workstation. Average number of visual glances at the
prior mammograms per case measured by analysis of recorded video footage showed an increase if the prior
mammograms were digitised, rather than displayed on a multi-viewer (p<.05). This finding has potential implications for
mammographer performance in the transition to digital mammography in the UK
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