Tobii Pro Nano User manual

Tobii Pro Nano Eye Tracker
User’s Manual

User’s manual Tobii Pro Nano Eye Tracker
Version 1.0.1
11/2018
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Con en subjec o change wi hou no ice.
Please check Tobii web si e www. obiipro.com for upda ed
versions of his documen .

Table of Con en s
1 In roduc ion.................................................................................................................................... 1
1.1 Overview...............................................................................................................................1
1.2 Applica ion Areas...................................................................................................................1
1.3 Basic Opera ing Principles......................................................................................................1
1.3.1 Recommended Screen Arrangemen s .......................................................................2
1.4 Sof ware Compa ibili y and Limi a ions......................................................................................2
1.4.1 Pro Nano Compa ibili y Overview ..............................................................................2
2 Hardware Package Con en ........................................................................................................... 3
2.1 Available Accessories.............................................................................................................3
3 Produc Care ................................................................................................................................. 4
3.1 Opera ional Environmen .........................................................................................................4
3.2 Transpor a ion and S orage .....................................................................................................4
3.3 A aching and De aching he Eye Tracker o Lap ops and Table s .................................................4
3.4 Cleaning ...............................................................................................................................5
3.5 Disposing of Pro Nano............................................................................................................5
4 Se ing up Pro Nano....................................................................................................................... 6
4.1 Se ing up he Pro Nano Hardware ...........................................................................................6
4.2 Ins alling Pro Nano Drivers ......................................................................................................6
4.3 Configuring he Pro Nano Eye Tracker ......................................................................................6
4.3.1 Advice for Experienced Users ...................................................................................6
4.4 S ar Experimen ing ................................................................................................................8
4.5 Keeping Your Eye Tracker Upda ed ..........................................................................................8
4.6 Tobii Pro Suppor ...................................................................................................................8
4.7 Advanced Se ups...................................................................................................................9
4.7.1 Al erna e Se up wi h a Tripod....................................................................................9
4.7.2 Al erna e Se up wi h a Mobile Device S and ...............................................................9
Appendix A Pro Nano – Specifica ions ............................................................................................. 10
A1 Eye- racking specifica ions....................................................................................................10
A2 Eye-Tracker Specifica ions....................................................................................................11
A3 Compliance and Cer ifica ion.................................................................................................11
A4 Sof ware Op ions.................................................................................................................12
A5 Sys em requiremen s ............................................................................................................12
Appendix B Glossary ........................................................................................................................ 13
Appendix C Safe y Informa ion ......................................................................................................... 15
C1 Safe y.................................................................................................................................15
C1.1 Emergency Warning..............................................................................................15
C1.2 Infrared Warning...................................................................................................15
C1.3 Epilepsy Warning..................................................................................................15
C1.4 Child Safe y .........................................................................................................15
C1.5 Do no open Tobii Pro Nano ...................................................................................15
C1.6 Environmen .........................................................................................................16
C2 O her limi a ions and considera ions .......................................................................................16
C2.1 In ended use ........................................................................................................16
C2.2 Ligh condi ions ....................................................................................................16
C2.3 Eyelashes.............................................................................................................16
C2.4 Droopy eyelids......................................................................................................16

1 Introduction
The Tobii Pro Nano welcomes you o he world of eye- racking s udies. Pro Nano is a small and por able eye racker ha you
can use for conduc ing s udies on lap ops, PC moni ors up o 19ʺ(16:9), mobile devices (using he mobile device s and), real-
world in erfaces, projec ions, simula ors, and TV screens. I is designed for por abili y, versa ili y and ease of use. The design al-
so encourages an in roduc ion o ex ensive s udies in o human behavior for educa ional and research purposes.
1.1 Overview
Tobii Pro Nano is our smalles , mos ligh -weigh research grade eye racker, fea uring he la es echnology advancemen s from
Tobii Pro. The Pro Nano device measures 170 mm (6.69’’) long and weigh s 59 grams (2.1 oz.), and uses a sampling ra e of 60
Hz.
Use Pro Nano on:
• Windows lap ops and Windows able s
• PC moni ors, 19″(16:9) or less as op imum size
• Mobile devices, wi h our Mobile Device S and
• Real-world se ups like physical objec s and social in erac ions, wi h he Tripod S and
• Projec ions, simula ors, and larger screens, wi h he Tripod S and
1.2 Application Areas
Pro Nano is primarily in ended for fixa ion-based eye racking s udies on lap ops and Windows able s. The Pro Nano sys em
has been es ed and proven capable of racking a large propor ion of he popula ion in regards of gender and e hnici y, wi h very
high accuracy and precision on por able screens. I s discre e appearance, wi h fully embedded processing of eye racking da a,
encourages for flexible and unob rusive da a collec ion me hods. The eye racker a aches easily wi h supplied moun ing pla es
on various screens and connec s via a USB 2.0 por o your Windows 10 compu er.
Pro Nano is perfec for any researcher who wan s o ge s ar ed wi h or explore quali y eye racking as a research me hod o
perform fixa ion-based eye racking s udies:
• Psychology and cogni ion
• Package design in marke ing research
• User in erface design and developmen
Pro Nano is our smalles research graded eye racker designed for por able labs o enable easy da a collec ion in he field:
• Make your own por able research lab ha fi s in a rucksack
• Collec da a wherever your par icipan s are, for ins ance a universi ies, hospi als, and public spaces
Pro Nano is well sui ed for equipping universi ies wi h por able eye racking solu ions o allow s uden s o ry ou eye racking
and build knowledge how he echnology can be used in differen fields, answer research ques ions and enhance commercial
endeavors.
1.3 Basic Operating Principles
During racking, eye rackers from Tobii Pro use infrared illumina ors o genera e reflec ion pa erns on he corneas of he par ic-
ipan ’s eyes. These reflec ion pa erns, oge her wi h o her visual da a abou he par icipan , are collec ed by image sensors. So-
phis ica ed image processing algori hms iden ify relevan fea ures, including he eyes and he corneal reflec ion pa erns. The
Pro Nano is a single camera sys em ha uses a combina ion of dark and brigh pupil racking. Complex ma hema ics is used o
calcula e he 3D posi ion of each eyeball, and finally he gaze poin ; in o her words, where he par icipan is looking.
Eye rackers from Tobii Pro are primarily designed for use in indoor office environmen s wi h adul par icipan s.
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US 1 In roduc ion 1

1.3.1 Recommended Screen Arrangemen s
Pro Nano is primarily in ended for eye racking s udies on small screens, such as lap ops and Windows able s. The eye racker
should herefore be moun ed on a 19” screen or smaller (aspec ra io 16:9); see sec ion 3.3. The par icipan should si 45–85
cm from he eye racker o ensure high racking accuracy on he en ire screen.
1.4 Software Compatibilit and Limitations
Pro Nano is connec ed o a compu er via a s andard USB 2.0 in erface. All eye racking processing is done in he in ernal Eye
Chip.
1.4.1 Pro Nano Compa ibili y Overview
Pla form suppor Windows 10, Professional or En erprise edi ions
Tobii Pro Sof ware suppor Tobii Pro Lab version 1.101 or la er
Tobii Pro Eye Tracker Manager version 1.11 or la er
SDK suppor Tobii Pro SDK version 1.6.0 or la er
21 In roduc ion Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

2 Hardware Package Content
Pro Nano eye racker
USB 2 ex ension cable, 1 m
Travel case
Safe y and Compliance and Ins alla ion Guide
Two cleaning wipes for cleaning he screen bezel before affixing he moun ing pla e
Four moun ing pla es wi h non-permanen adhesive for a aching he eye racker o a screen
2.1 Available Accessories
• Mobile Device S and
• Addi ional Moun ing Bracke s
• Tobii Pro Tripod S and
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US 2 Hardware Package Con en 3

3 Product Care
3.1 Operational Environment
The recommended range for empera ure and humidi y during opera ions is:
•Temperature: 10°C o 35°C (50°F o 95°F)
•Humidity: Max 20% o 95% (no condensa ion on he device)
3.2 Transportation and Storage
Use he provided case when raveling wi h he eye racker be ween es loca ions.
For shipping and s orage, use he original packing.
For ranspor a ion and s orage, he recommended range for empera ure and humidi y for he device is as follows:
•Temperature: -40°C o 70°C (-40°F o 158°F)
•Humidity: 20% o 95% (no condensa ion on he device)
Pro Nano is no wa erproof or wa er resis an . The device should no be kep in excessively humid, damp or we condi-
ions. Do no submerge he device in wa er or in any o her liquid. Be careful no o spill liquids on he device.
3.3 Attaching and Detaching the E e Tracker to Laptops and Tablets
To ensure quali y in eye racking da a, he Pro Nano hardware package include moun ing pla es ha can be affixed o a lap op
or a able . You can easily snap he eye racker on and off he lap op or able by using he magne ic moun ing pla e. The moun -
ing pla e s icks o he frame wi h a special adhesive ha doesn’ damage he underlying surface when he moun ing pla e is
removed.
Ensure ha he moun ing pla e is affixed horizon ally.
Remove he pro ec ion from he adhesive s icker. Pu he
moun ing pla e horizon ally below he cen er of he screen.
Snap he Pro Nano eye racker o he moun ing pla e.
43 Produc Care Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

If he screen bezel is hinner han he wid h of he eye racker, affix he moun ing pla e as low as possible on he
screen frame, or direc ly on he screen.
• Don’ use his se up if you in end o pu s imuli in he lower par of he screen, as hey migh become covered by
he eye racker.
• We recommend ha you remove he moun ing pla e before closing he lid of he lap op.
• Use Eye Tracker Manager’s Advanced Display Se up, and selec a nega ive value for he dis ance be ween he
eye racker and he lower end of he display screen. Al erna ively, use he ripod accessory and moun he eye
racker away from he screen (see 4.7.1).
3.4 Cleaning
• Before cleaning he Pro Nano eye racker, unplug i s USB cable.
• Use a sof , sligh ly damp, lin -free clo h and clean he eye racker’s fron gen ly.
• Avoid ge ing mois ure in openings on he device.
• Don’ use window cleaners, household cleaners, aerosol sprays, solven s, alcohol, ammonia, or abrasives.
Scra ches on he fron surface of he eye racker may impair i s performance.
3.5 Disposing of Pro Nano
Don’ dispose of he Pro Nano eye racker in general household or office was e. Follow your local regula ions for disposal of
elec ronic equipmen .
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US 3 Produc Care 5

4 Setting up Pro Nano
You s ar se ing up Pro Nano by unpacking he disassembled eye racker. A he end of he se up, you have a verified ins alla-
ion ha is ready for use.
Download Pro Nano’s se up documen a ion from he Tobii Pro websi e a www. obiipro.com/pronano/ge s ar ed
4.1 Setting up the Pro Nano Hardware
1. Remove he Pro Nano eye racker from i s packaging.
2. Moun he eye racker on your compu er.
3. Connec he eye racker’s USB cable o a USB 2.0 Type A por in your compu er.
4.2 Installing Pro Nano Drivers
If you earlier ins alled he Tobii 4C eye racker in your compu er, you mus unins all all 4C-rela ed sof ware before in-
s alling he Pro Nano drivers.
When you ins all he Pro Nano drivers and sof ware on a Windows compu er, Tobii Pro Eye Tracker Manager enables you o
carry ou he procedures swif ly and almos au oma ically.
1. Download he Pro Eye Tracker Manager from www. obiipro.com/pronano/ge s ar ed and ins all i .
2. Open he Eye Tracker Manager. I displays wha eye rackers are discovered and connec ed.
3. If your Pro Nano is connec ed o he USB por bu doesn’ appear in he lis of Connec ed eye rackers, click “Ins all or
Upda e Eye Trackers”.
4. In he “Ins all or upda e Eye Trackers” dialog, selec he desired eye rackers, in his case Tobii Pro Nano, and click “In-
s all drivers”.
5. Eye Tracker Manager downloads he ins aller and execu es he ins alla ion.
6. Comple e he ins alla ion by shutting off and rebooting Eye Tracker Manager. The eye racker appears in he Eye Tracker
Manager display.
4.3 Configuring the Pro Nano E e Tracker
S ar by selec ing he eye racker you wan o use:
1. Open he Eye Tracker Manager.
2. Click on he eye racker you wan o use. (If you are uncer ain, check he serial number on he eye racker and ma ch i o
he serial number displayed in Eye Tracker Manager.) The eye racker’s se ings appear and you can configure hem.
Here is some configura ion advice:
•Eye Tracker Settings: The original values here are se by defaul .
•Display Setup: If you have a pre-exis ing Se up, selec i in he Select setup dropdown. O herwise, click on Create
New and follow he ensuing ins ruc ions.
•Calibration: Calibra e your device by clicking on he Start Calibration bu on. Follow he s ep-by-s ep ins ruc ions ha
appear on he screen.
•User Position Guide: This func ionali y helps he es person o find an apporpria e sea ing posi ion in fron of he eye
racker.
•Eye Images: This func ionali y is no suppor ed by Pro Nano.
•Diagnostics: If you con ac Tobii Pro for a suppor issue, your con ac may reques a diagnos ics file. If so, email he file
o Tobii Pro suppor .
4.3.1 Advice for Experienced Users
A par icipan can be calibra ed wi h Pro Nano even when only one eye was successfully calibra ed. Tha calibra ion
ge s copied o he “failed” eye, and his migh cause poor da a for ha eye.
64 Se ing up Pro Nano Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

Tips! Use he Lef and Righ eyes resul s in Eye Tracker Manager and Pro Lab o de ermine whe her bo h eyes were
calibra ed successfully. You can also choose o analyze he da a only for he eye ha successfully calibra ed.
For Pro Nano you ge only one vec or for he calibra ion resul s, hereby providing informa ion on he average es i-
ma ed accuracy, bu no on he es ima ed precision.
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US 4 Se ing up Pro Nano 7

4.4 Start Experimenting
When you are in Eye Tracker Manager, ac iva e Gaze Tracing by click on “Gaze Visualiza ion” a he op of he Connected Eye
Tracker screen. A hazy blob appears on he screen, indica ing where your a en ion is focused.
Use his func ionali y o verify ha your eye racker is running, ha he display is correc ly se up, and ha your eye racker is
calibra ed.
The gaze race doesn’ fully indica e curren accuracy or precision.
4.5 Keeping Your E e Tracker Updated
From ime o ime, Tobii Pro releases upda es for he eye racker’s driver and firmware in order o improve performance and/or
in roduce new func ionali ies. A Pro Nano upda e consis s of a new driver wi h ma ching firmware. Therefore, check our websi e
page regularly for news and informa ion abou upda es. Also, we recommend ha you ac iva e he func ionali y for upda e no ifi-
ca ions in Eye Tracker Manager.
Procedure for ac iva ing upda e no ifica ions:
1. Open he Se ings & No ifica ions dialog box.
2. Enable he swi ches under “No ifica ions”.
3. A fresh upda e no ifica ion is indica ed by a iny red bell on an emp y Eye Tracker ile.
You de ermine wha firmware version you use in your connec ed Pro Nano(s) by ins alling he desired driver version in your com-
pu er. Use he Eye Tracker Manager’s “Ins all or Upda e Eye Trackers” func ionali y o check available releases.
4.6 Tobii Pro Support
Our friendly suppor crew can be reached via he Tobii Pro Learn and Suppor web page.
84 Se ing up Pro Nano Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

4.7 Advanced Setups
4.7.1 Al erna e Se up wi h a Tripod
Pro Nano moun ed on a ripod in fron of a wide silver screen.
If you wish o use a movie screen, you se up he hardware in a sligh ly differen manner:
1. Selec a sui able loca ion and se up he screen.
2. Se up he projec or and connec i o he lap op.
3. Moun he Pro Nano eye racker on a separa e ripod and connec i s USB cable o he lap op.
4. Place he par icipan 45–85 cm from he eye racker. Use he posi ioning guide in he Eye Tracker Manager o de ermine
whe her he eye racker can de ec he par icipan ’s eyes.
4.7.2 Al erna e Se up wi h a Mobile Device S and
Tobii Pro has published a PDF wi h de ailed descrip ion for how o se up a mobile device s and: Tobii Pro Mobile Device S and
user manual. Download i he Tobii Pro websi e.
Procedure for se ing up a Pro Mobile Device S and and a Pro Nano eye racker.
1. Go o chap er 3 in he user manual for he Pro Mobile Device S and.
2. Selec a sui able loca ion and se up he mobile device s and as described in chap er 3.
3. Moun he Pro Nano eye racker in i s slo , see sec ion 3.1, i ems 10 and 11.
4. Connec he Pro Nano’s USB cable o your lap op.
5. A ach your mobile device in he s and, as described in sec ion 3.2, and connec i o your lap op.
6. Place he par icipan 45–85 cm from he eye racker. Use he posi ioning guide in he Eye Tracker Manager o de ermine
whe her he eye racker can de ec he par icipan ’s eyes.
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US 4 Se ing up Pro Nano 9

Appendix A Pro Nano – Specifications
A1 E e-tracking specifications
The charac eris ics of he gaze da a from an eye racker can be described in erms of accuracy and precision. Accuracy de-
scribes he angular average dis ance from he ac ual gaze poin o he one measured by he eye racker. Gaze precision de-
scribes he spa ial varia ion be ween successive samples collec ed when he subjec fixa es a a specific poin on a s imuli.
Eye- racking echnique Corneal reflec ion, dark and brigh pupil illumina ion, one cam-
era sys em
Sampling frequency 60 Hz
Accuracy* 0.3° a op imal condi ions (down o 0.1°)
Precision* 0.10° RMS a op imal condi ions (down o 0.06°)
Binocular eye racking Yes
To al sys em la ency 17 ms
Blink recovery ime 1 frame (immedia e)
Gaze recovery ime 250 ms
Freedom of head movemen Wid h × heigh : 35 cm × 30 cm (13,78" × 11,81") a 65 cm (a
leas one eye racked)
Opera ing dis ance 45–85 cm (18”–33”) from he eye racker’s reference poin
Max gaze angle 30 degrees
Max screen size 19” (16:9 aspec ra io)
Da a sample ou pu ** Times amp
Gaze origin
Gaze poin
Pupil diame er
Validi y code
*Tobii Pro uses an ex ensive es me hod o measure and repor performance and quali y of da a. The da a quali y es repor
provides de ailed informa ion. Download i a : h ps://www. obiipro.com/pop-ups/me rics-repor -nano/
** For more informa ion abou ou pu da a and he supplemen ary da a s ream, download he Pro SDK documen a ion from Tobii
Pro’s websi e: h p://www. obiipro.com/produc -lis ing/ obii-pro-sdk/.
10 Appendix A Pro Nano – Specifica ions Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

A2 E e-Tracker Specifications
Dimensions 170 mm × 18 mm × 13 mm (6.69“ × 0.71“ × 0.51“)
Weigh 59 g (2.1 oz)
Connec ors USB 2.0 Type A
Eye racker processing Tobii EyeChip™ wi h fully embedded processing
Power consump ion Typically* 1.5 W via single USB 2
*Typical power consump ion for an office wi h he par icipan si ing a 65 cm from he eye racker. If he par icipan si s far from
he eye racker, he illumina ors need more power o genera e good eye- racking. In such a case he average power ops a 2.3
W. A USB 2.0 por s ypically ou pu s 2.5 W. If, for some reason your compu er USB 2 por doesn’ provide enough power o
he eye racker, he Pro Nano will no work. In hose rare cases, we recommend connec ing an ex ernal powered USB hub be-
ween he compu er and he eye racker.
A3 Compliance and Certification
The cer ifica ion and compliance s a emen s in his sec ion apply o he Pro Nano eye racker uni .
Pro Nano has been es ed and found safe for indoor use, and is in ended for office and indus rial environmen s, and for labora o-
ries, classrooms and homes. The produc complies wi h regula ions rela ed o elec ro-magne ic safe y and eye safe y. Pro Nano
adheres o he regula ions rela ed o sus ainabili y, such as res ric ions for hazardous subs ances and was e.
Pro Nano has marke compliance in he following coun ries or regions:
• European Economic Area
• USA
• Canada
• Japan
• China
• Aus ralia
• New Zealand
• Sou h Korea
Safety
Safe y s andards: • IEC 60950-1:2005 +A1 +A2, Safe y of Informa ion Technol-
ogy Equipmen
• IEC/EN 62471:2008, Pho o Biological Safe y of Lamps and
Lamp Sys ems
Cer ifica ion and declara ion
of conformance:
CE, RCM
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US Appendix A Pro Nano – Specifica ions 11

EMC
EMC s andards: • EN 55032:2015, Elec romagne ic compa ibili y of mul imedia
equipmen . Emission requiremen s
• EN 55024:2010+A1:2015, Informa ion echnology equip-
men , Immuni y charac eris ics, Limi s and me hods of
measuremen
• EMC Emission: EN 61000-6-3:2007, Generic Emission
s andard for residen ial, commercial and ligh indus ry
environmen s
• EMC Immuni y: EN 61000-6-1:2007, Generic Emission
s andard for residen ial, commercial and ligh indus ry
environmen s
• FCC par 15, Class B
• ICES-003, Class B
• AS/NZS CISPR32:2015, Elec romagne ic compa ibili y of
mul imedia equipmen - Emission requiremen s
• KC s andard (KC-KN-32/35)
Cer ifica ion and declara ion
of conformance: CE, FCC par 15, Class B, ICES-003 Issue 5, KC s andard (KC-
KN-32/35), RCM
Direc ives: 2014/30/EU (EMC) - Elec romagne ic Compa ibili y Direc ive
Sustainability
Direc ives: • 2011/65/EU (RoHS) - Res ric ion of Hazardous Subs ances
Direc ive
• 2012/19/EU (WEEE) - Was e Elec rical and Elec ronic
Equipmen Direc ive
A4 Software Options
The Pro Nano eye racker is connec ed by an USB-cable o he compu er running he sof ware applica ion.
The Pro SDK offers a broad se of ools in order o make i simple o develop niche applica ions or scrip s across mul iple pla -
forms and in a wide range of programming languages.
Download links
• Tobii Pro SDK: h p://www. obiipro.com/produc -lis ing/ obii-pro-sdk/
• Tobii Pro Eye Tracker Manager: h ps://www. obiipro.com/produc -lis ing/eye- racker-manager/
• Tobii Pro Lab: h ps://www. obiipro.com/produc -lis ing/ obii-pro-lab/
Pro Nano is no compa ible wi h Pro SDK version 1.5 or older, Eye Tracker Manager version 1.10 or older, nor Pro
Lab version 1.98 or older. Pro Nano is no compa ible wi h Tobii S udio.
A5 S stem requirements
Opera ing sys em Windows 10 Professional or En erprise edi ions
CPU 1 GHz, 2 cores
RAM 2 GB RAM memory
Sof ware for eye- racking research migh require higher RAM
Connec ors USB 2.0 Type A
12 Appendix A Pro Nano – Specifica ions Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US

Appendix B Glossar
Binocular eye racking Tracks and repor s da a for bo h lef and righ eye.
Blink recovery ime ( ime o racking recovery for blinks) When a subjec blinks, he eye racker loses he abili y o
rack eye gaze because he eye is covered by he eyelid. If
he pupil is occluded for only a shor period (a few hundred
milliseconds), he sys em will regain racking immedia ely
when he pupil becomes visible again, bu only if he subjec
has main ained approxima ely he same head posi ion during
he blink. Da a during blinks are only los when he pupil is
occluded, i.e. during he eye lid movemen i self or when he
eye is closed.
Eye- racking processing uni The CPU in which he gaze processing and calcula ions are
made. Tobii Pro eye rackers have ei her an embedded CPU
in he eye racker or an ex ernal processing uni .
Eye- racking echnique Tobii Pro Eye Trackers use wo echniques o de ermine eye
posi ion: 1. Brigh pupil eye racking, where an illumina or is
placed close o he op ical axis of he imaging device, caus-
ing he pupil o appear li up ( he same phenomenon ha
causes red eyes in pho os). 2. Dark pupil eye racking where
he illumina or is placed away from he op ical axis, causing
he pupil o appear black.
Freedom of head movemen Describes he region in space where he par icipan may
move his/her head and s ill have a leas one eye wi hin he
eye racker’s field of view.
Gaze accuracy Describes he angular average dis ance from he ac ual gaze
poin o he one measured by he eye racker.
Gaze da a ou pu frequency The number of da a samples per second ou pu for each eye.
Gaze precision Describes he spa ial angular varia ion be ween individual
and consecu ive gaze samples (Roo Mean Square), calcu-
la ed on raw da a.
Gaze precision fil ered Describes he spa ial angular varia ion be ween individual
and consecu ive gaze samples (Roo Mean Square), calcu-
la ed af er a smoo hing fil er has been applied o he raw da a
- Savi zky A. and Golay, J.E., 1964. Smoo hing and Differen-
ia ion of Da a by Simplified Leas Squares Procedure Sa-
vi zky-Golay. Anal. Chem., vol.36, pp. 1627-1639. Fil er
se ings: Polynomial order 2, wi h a 20 millisecond sampling
window.
Gaze recovery ime ( ime o racking recovery af er los
racking)
An eye racker working in a na ural user environmen may oc-
casionally lose rack of he subjec ’s eyes, e.g., when he
subjec comple ely urns away from he racker. If a period of
a few hundred milliseconds elapses during which he eye
racker is unable o de ec he eyes in close proximi y o
where hey were las de ec ed, he eye racker will s ar
searching for he eyes wi hin he en ire head movemen box.
The s a ed measuremen is he ypical ime o racking recov-
ery in such a si ua ion.
Max gaze angles The maximum gaze angle for wi ch he eye racker can per-
form robus and accura e racking by finding a leas one eye.
The gaze angle is he angle ABC wi h A = cen er of he eye
racking sensors (midpoin be ween he wo eye racking
sensors, for dual camera sys ems, and cen er of he eye
racking sensor for single camera sys ems), B = eye posi ion
(midpoin be ween he lef and he righ eye) and C = s imuli
poin .
Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US Appendix B Glossary 13

Max head movemen speed Describes he maximum head movemen speed allowed
while main aining robus racking. The specified number is
for sideways head movemen .
Opera ing dis ance Describes he minimum and maximum dis ances be ween
he subjec ’s eyes and he surface covering he eye racker
sensors a which eye racking can be done while main aining
robus racking.
Processing La ency Describes he ime required by he eye racker processor o
perform image processing and eye gaze compu a ions.
Sampling ra e Number of da a samples per second.
Times amp precision as specified in each da a sample The emporal devia ion of he imes amp in he da a sample
received by he clien applica ion. This includes any offse in
he clock sync be ween he eye racker processing uni and
a ypical clien compu er.
To al sys em la ency The dura ion from he mid-poin of he eye image exposure,
o when a sample is available via he API on he clien com-
pu er. This includes half of he image exposure ime, image
read-ou and ransfer ime, processing ime and ime o
ransfer he da a sample o a clien compu er.
14 Appendix B Glossary Tobii Pro Nano Eye Tracker User’s manual v.1.0.1 - en-US