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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.


The final version of the system
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Fig3: The final version of the system

Mentions: Gaze and head tracking The system uses IR-diodes to illuminate the face of the subject in order to minimize the effect of varying lighting conditions and use the reflections of these IR flashes on the cornea (“glints”) to find the centre of the eyes, rather than other systems where the eye centre is estimated using the head model (Fig. 2). This allows a more accurate identification of gaze direction with fewer errors in the head pose estimation. This feature, i.e. the possibility to measure both eye and head components is extremely important since the visual field proposed in this work is wide and each movement of the infant to reach the audio-visual stimulus is composed of both components. Finally, in order to complete the system and to adjust the setup according to the infant’s needs, a seat has been purposely designed allowing for adjustments to the height (the infant’s eyes should be at the height of the screen’s centre) and the distance from the screen (≈60 cm). In addition, two different accessories complete the seat that allow us to position infants that have not yet reached the stage of torso control, as well as infants that can maintain the sitting posture independently (Fig. 3).Fig. 2


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)

The final version of the system
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig3: The final version of the system
Mentions: Gaze and head tracking The system uses IR-diodes to illuminate the face of the subject in order to minimize the effect of varying lighting conditions and use the reflections of these IR flashes on the cornea (“glints”) to find the centre of the eyes, rather than other systems where the eye centre is estimated using the head model (Fig. 2). This allows a more accurate identification of gaze direction with fewer errors in the head pose estimation. This feature, i.e. the possibility to measure both eye and head components is extremely important since the visual field proposed in this work is wide and each movement of the infant to reach the audio-visual stimulus is composed of both components. Finally, in order to complete the system and to adjust the setup according to the infant’s needs, a seat has been purposely designed allowing for adjustments to the height (the infant’s eyes should be at the height of the screen’s centre) and the distance from the screen (≈60 cm). In addition, two different accessories complete the seat that allow us to position infants that have not yet reached the stage of torso control, as well as infants that can maintain the sitting posture independently (Fig. 3).Fig. 2

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.