Abstract

Introduction

Results

Acknowledgement

StudyDesign

DisplacedObjectRecognitionTask(DOR)TheDORtasktestsananimal’sabilitytorememberaspatialenvironment.Inthestandardversionofthetask,twoidenticalobjectsarepresentedtotheanimal.Afterthispresentationthesametwoobjectsareagainpresented,butthistimeoneobjectisdisplaced.Iftheanimalrememberstheoldspatialenvironmentitwillnoticethespatialchangeandwilldisproportionallyexplorethedisplacedobject.

NovelObjectRecognitionTask(NOR):TheNORtasktestsananimal’sabilitytorememberanobject.Inthestandardversionofthetask,twoidenticalobjectsarepresentedtotheanimalfora15-minuteperiodonthedayoftesting.Afterthispresentation,thehamsterwasreturnedtoitscagefora3-hourdelayinterval.Followingthedelay,thehamsterwasplacedbackintothesamecontainerbutwithoneofthetwoobjectsreplacedbyanovelobject.Iftheanimalrememberstheoldobject,itwilldisproportionallyexplorethenovelobject.

ActivityTest:Activitywasmeasuredontwoconsecutivedaysinalargeopenfieldbyavideotrackingsystem.Thetestingroomissetupwitharoundtablewithadiameterof177cm.Thetablewaspaintedwhite.Thehamsterwasplacedinthecenterofthetableandallowedtoexplorethetablefor10minuteson2consecutivedays.

StudyObjectives

Results

Discussion/FutureDirections

Conclusion

Mobile technology has become an indispensible part ofdaily life for many people. Most people already ownsmartphones that contain sensors with potentiallyhospital grade measurement capabilities. MaximIntegrated have developed MaximFAST that are currentlyinstall in phone models that are capable of sensitive,accurate, and reproducible heart rate (HR) and bloodoxygenation (SpO2) measurements, by analyzingphotoplethysmography (PPG), which would allow formonitoring of patients with chronic diseases in homesettings. Furthermore, it would also have widespreadapplication in delivering better and higher quality care inresources-poor/ -limited areas of the world. While thebiosensor has been tested experimentally against FDAapproved vital sign montior that are currently in clinicaluse, no patient testing has taken place thus far.

This pilot study, in collaboration with UCSD and Specialistin Global Health, assessed the use of MaximFAST in theoutpatient clinic and emergency department againstWelch-Allyn vital sign monitor, using either Masimo orNellcor oximetry, which are considered as the Standard-of-Care monitors currently in use at UCSD and otherhealthcare systems. Findings of this pilot studydemonstrated the accuracy and usability of MaximFASTand also provided foundation for future larger clinicalstudies, but more importantly, the importance of andmutually beneficial collaborative relationship betweenindustry and academic medical centers in the continueddevelopment of this new technology.

This study is supported by an investigator-initiated grantfrom Maxim Integrated.

1. MaximFAST can provide accurate HR and SpO2measurements that are comparable to that ofcommercially available vital sign machines.

2. Collaborative studies between industry and academicmedical centers are mutually rewarding and beneficial.

VitalSignMeasurementsusingMaximIntegratedMobilePhone-embeddedBioSensor areAccurateandComparabletoStandard-of-CareMonitorinClinicalSettings

SamuelPan,MD1, JonathanGonzalez-Garcia2,Abdul-AzizHashi3,FlorinVaida,PhD4,StevenHuang5,Ferit Boyukkececi5,CetinSeren5,SaraHBrowne,MD1

1DivisionofInfectiousDiseases,DepartmentofMedicine,UniversityofCalifornia,SanDiego,LaJolla,CA,2DepartmentofMedicine,UniversityofCalifornia,SanDiego,LaJolla,CA,3DepartmentofBiochemistryandCellularBiology,UniversityofCalifornia,SanDiego,LaJolla,CA,4DepartmentofFamilyMedicineandPublicHealth,UniversityofCalifornia,SanDiego,LaJolla,CA,5MaximIntegrated,SanJose,CA

vMaximFAST potentially have a wide range of possibleapplications, such as

a) Outpatient management of patientwith chronic conditions such asasthma, COPD, and congestive heartfailure (CHF), or post-transplantation,allowing for early intervention andavoiding unnecessary hospitalization;

b) post ED or hospital discharge follow-up;

c) Reduction of morbidity, mortality andcosts associated with unnecessaryhospital admissions/ readmissions

d) Provide much needed clinical tool inmany resource-poor/-limited areas ofthe world

v Goal is to develop a device that is mobile, wireless,user-friendly, and capable of providing the entiresuite of vital sign measurements (heart rate, SpO2,respiratory rate, and blood pressure).

v Current and future collaborations between industryand academic medical centers will be essential fordevelopment of target end-user populations,potentially unexpected user issues, and productrefinement

This is a non-randomized, one-time measurement of HRand SpO2 of patients who present to the emergencydepartment or outpatient clinics at UCSD.

After providing consent, each participant was seatedwith both arms at the sides of his/her body and theforearms resting on their legs. Participant was instructedon how to place the index finger against the sensor onthe back of MaximFAST, as shown below,

LeftIndexFinger RightIndexFinger

Measurement 1 Welch-Allyn unit1 Welch-Allyn unit2

Measurement2 MaximFAST unit1 MaximFAST unit2

Measurement3 MaximFAST unit2 Welch-Allyn unit1

Measurement 4 Welch-Allyn unit2 MaximFAST unit1

• It is essential to develop a portable and easy-to-usedevice to provide comprehensive and accurateoutpatient vital sign monitoring

• MaximFAST developed by Maxim Integrated iscapable of taking accurate vital sign measurements,based on internal company testing

• MaximFAST was tested in various clinical settings as acollaboration with the University of California, SanDiego (UCSD)

• The pilot study showed that vital sign measurementstaken by MaximFAST are accurate and comparable

Four sets of measurements were taken, as describedbelow. A stable PPG waveform must be obtained for atleast 10 seconds before the measurements areconsidered as valid and recorded.1). Welch-Allyn Spot VS monitors, unit 1 (with Masimooximetry) on left index finger and unit 2 (with Nellcoroximetry) on right index finger;2). MaximFAST on both index fingers;3). MaximFAST on left index finger and Welch-Allyn SpotVS monitor on right index finger;4). Welch-Allyn Spot VS monitor on left index finger andMaximFAST on right index finger.

DataAnalysisForMaximengineerstofillin

Table 1 – Performance comparison of MaximFAST andWelch-Allyn unitsRoot mean square error (RMSE) of measurements withrespect to reference. Success Rate is the percentage ofmeasurements that are inside an interval whose centerpoint is the corresponding reference measurement; forHR, the interval is ±5% deviation and for SpO2, theinterval is ±3% deviation.

Figure 1 – Error of MaximFAST SpO2 readings arecomparable to SpO2 readings by Welch Allyn withMasimo oximetry.Error of MaximFAST readings were calculated as RMSE ofdifferences of MaximFAST and Masimo measurementswhile holding Masimo as a constant. Published deviationfor Masimo is <±2% with maximum absolute deviation of5%, therefore, MaximFAST’s accuracy is 3% with apositive bias of 0.85 BPM.

Figure 2 – Error of MaximFAST SpO2 readings arecomparable to SpO2 readings by Welch Allyn withNellcor oximetry.Error of MaximFAST readings were calculated as RMSE ofdifferences of MaximFAST and Nellcor measurementswhile holding Nellcor as a constant. Published deviationfor Nellcor is <±3% and maximum absolute deviation is5%, therefore, MaximFAST’s accuracy is 2% with apositive bias of 0.42 BPM.

1. MaximFAST shows good performance in SpO2measurement as its deviation is in the same limits ofMassimo vs. Nellcorr deviation.

2. The analyses above show that MaximFAST’s accuracyfor SpO2 measurement can be estimated as less than±3%.

3. MaximFAST can be used in a variety of clinicalsettings and in patients with various underlyingchronic illness.

4. Collaborative study such as this provide developmentteam potential challenges and issues that mayencounter with end users.

During the study, it was noted that skin conditions, handcleanliness, excessive motions from tremors, orunderlying cardiac arrhythmia were all noted to affectMaximFAST’s ability to acquire stable PPG.