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

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

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

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

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

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

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

How new readers perform as compared to more experienced readers on the PERFORMS scheme

How new readers perform as compared to more experienced readers on the PERFORMS schem