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A new system for quantitative evaluation of infant gaze capabilities in a wide visual field.

Pratesi A, Cecchi F, Beani E, Sgandurra G, Cioni G, Laschi C, Dario P - Biomed Eng Online (2015)

Bottom Line: We developed a system able to measure infant's gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°.The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.The proposed system is suitable for measuring and evaluating infant's gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment.

View Article: PubMed Central - PubMed

Affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025, Pontedera, Pisa, Italy. a.pratesi@sssup.it.

ABSTRACT

Background: The visual assessment of infants poses specific challenges: many techniques that are used on adults are based on the patient's response, and are not suitable for infants. Significant advances in the eye-tracking have made this assessment of infant visual capabilities easier, however, eye-tracking still requires the subject's collaboration, in most cases and thus limiting the application in infant research. Moreover, there is a lack of transferability to clinical practice, and thus it emerges the need for a new tool to measure the paradigms and explore the most common visual competences in a wide visual field. This work presents the design, development and preliminary testing of a new system for measuring infant's gaze in the wide visual field called CareToy C: CareToy for Clinics.

Methods: The system is based on a commercial eye tracker (SmartEye) with six cameras running at 60 Hz, suitable for measuring an infant's gaze. In order to stimulate the infant visually and audibly, a mechanical structure has been designed to support five speakers and five screens at a specific distance (60 cm) and angle: one in the centre, two on the right-hand side and two on the left (at 30° and 60° respectively). Different tasks have been designed in order to evaluate the system capability to assess the infant's gaze movements during different conditions (such as gap, overlap or audio-visual paradigms). Nine healthy infants aged 4-10 months were assessed as they performed the visual tasks at random.

Results: We developed a system able to measure infant's gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°. Moreover, the same system, thanks to different integrated software, was able to provide different visual paradigms (as gap, overlap and audio-visual) assessing and comparing different visual and multisensory sub-competencies. The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.

Conclusions: The proposed system is suitable for measuring and evaluating infant's gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment.

No MeSH data available.


Gaze calibration procedure. The red dot shows where the current un-calibrated gaze intersects a plane, orthogonal to the current world point and a vector pointing towards the centre of the eye. The blue dots represent all saved samples, whereas the green dots show the samples once the calibration algorithm has been run on them. Ideally the green dots should be in the middle of both the target. One circle in the target corresponds to ±2° of accuracy. We carefully checked that the blue dots were close together without outliers, and any outliers that were found were cleared and new samples were added again. We manually repeated this operation until the noise became smaller
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Fig5: Gaze calibration procedure. The red dot shows where the current un-calibrated gaze intersects a plane, orthogonal to the current world point and a vector pointing towards the centre of the eye. The blue dots represent all saved samples, whereas the green dots show the samples once the calibration algorithm has been run on them. Ideally the green dots should be in the middle of both the target. One circle in the target corresponds to ±2° of accuracy. We carefully checked that the blue dots were close together without outliers, and any outliers that were found were cleared and new samples were added again. We manually repeated this operation until the noise became smaller

Mentions: Thanks to SmartEye Pro 5.9 application, it was also possible to quantify the accuracy of the calibration points obtained during recording (Fig. 5). For each point we checked the accuracy and standard deviation of the calibration. The accuracy depended on various parameters such as: (a) distance from the cameras, that we assumed remained fixed (60 cm); (b) distance and position of the screens (fixed at 60 cm); (c) individual differences among infants that we did not include in this study [29]. The calibration was repeated until all calibration points had accuracy lower than 1°.Fig. 5


A new system for quantitative evaluation of infant gaze capabilities in a wide visual field.

Pratesi A, Cecchi F, Beani E, Sgandurra G, Cioni G, Laschi C, Dario P - Biomed Eng Online (2015)

Gaze calibration procedure. The red dot shows where the current un-calibrated gaze intersects a plane, orthogonal to the current world point and a vector pointing towards the centre of the eye. The blue dots represent all saved samples, whereas the green dots show the samples once the calibration algorithm has been run on them. Ideally the green dots should be in the middle of both the target. One circle in the target corresponds to ±2° of accuracy. We carefully checked that the blue dots were close together without outliers, and any outliers that were found were cleared and new samples were added again. We manually repeated this operation until the noise became smaller
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4562110&req=5

Fig5: Gaze calibration procedure. The red dot shows where the current un-calibrated gaze intersects a plane, orthogonal to the current world point and a vector pointing towards the centre of the eye. The blue dots represent all saved samples, whereas the green dots show the samples once the calibration algorithm has been run on them. Ideally the green dots should be in the middle of both the target. One circle in the target corresponds to ±2° of accuracy. We carefully checked that the blue dots were close together without outliers, and any outliers that were found were cleared and new samples were added again. We manually repeated this operation until the noise became smaller
Mentions: Thanks to SmartEye Pro 5.9 application, it was also possible to quantify the accuracy of the calibration points obtained during recording (Fig. 5). For each point we checked the accuracy and standard deviation of the calibration. The accuracy depended on various parameters such as: (a) distance from the cameras, that we assumed remained fixed (60 cm); (b) distance and position of the screens (fixed at 60 cm); (c) individual differences among infants that we did not include in this study [29]. The calibration was repeated until all calibration points had accuracy lower than 1°.Fig. 5

Bottom Line: We developed a system able to measure infant's gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°.The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.The proposed system is suitable for measuring and evaluating infant's gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment.

View Article: PubMed Central - PubMed

Affiliation: The BioRobotics Institute, Scuola Superiore Sant'Anna, Viale Rinaldo Piaggio 34, 56025, Pontedera, Pisa, Italy. a.pratesi@sssup.it.

ABSTRACT

Background: The visual assessment of infants poses specific challenges: many techniques that are used on adults are based on the patient's response, and are not suitable for infants. Significant advances in the eye-tracking have made this assessment of infant visual capabilities easier, however, eye-tracking still requires the subject's collaboration, in most cases and thus limiting the application in infant research. Moreover, there is a lack of transferability to clinical practice, and thus it emerges the need for a new tool to measure the paradigms and explore the most common visual competences in a wide visual field. This work presents the design, development and preliminary testing of a new system for measuring infant's gaze in the wide visual field called CareToy C: CareToy for Clinics.

Methods: The system is based on a commercial eye tracker (SmartEye) with six cameras running at 60 Hz, suitable for measuring an infant's gaze. In order to stimulate the infant visually and audibly, a mechanical structure has been designed to support five speakers and five screens at a specific distance (60 cm) and angle: one in the centre, two on the right-hand side and two on the left (at 30° and 60° respectively). Different tasks have been designed in order to evaluate the system capability to assess the infant's gaze movements during different conditions (such as gap, overlap or audio-visual paradigms). Nine healthy infants aged 4-10 months were assessed as they performed the visual tasks at random.

Results: We developed a system able to measure infant's gaze in a wide visual field covering a total visual range of ±60° from the centre with an intermediate evaluation at ±30°. Moreover, the same system, thanks to different integrated software, was able to provide different visual paradigms (as gap, overlap and audio-visual) assessing and comparing different visual and multisensory sub-competencies. The proposed system endowed the integration of a commercial eye-tracker into a purposive setup in a smart and innovative way.

Conclusions: The proposed system is suitable for measuring and evaluating infant's gaze capabilities in a wide visual field, in order to provide quantitative data that can enrich the clinical assessment.

No MeSH data available.