ACCURACYSTATEMENT:HIGISTATIONANDSH-650HEALTHSTATION
Overview&RegulatoryContext
higiSHLLC(higi)isacertifiedQualityManagementSystemandMedicalDeviceStandards(ISO13485)
company.Itcomplieswithallregulationsassociatedwiththedesign,manufacturinganddistributionof
healthmonitoringtools.
InadditiontoISOcertification,higimedicaldeviceproductsreceiveFDAclearance(viathe510kprocess)
priortomarketintroductionintheUSA.
DefiningAccuracy
Accuracyrequirementsforthemedicaldevicesaregenerallyprescribedbyregulatoryauthoritiesasan
elementoftheassociatedclearanceprocess-FDA510(k)intheUSA,HealthCanadaMDLprocessin
Canada.
InthecaseoftheHealthStationsdevelopedbyhigi,accuracyisassessedbaseduponthedefinitionsfor
truenessandprecisionprovidedinISO5725(ISO5725-1).
Followingaredescriptionsofthetwocomponentswhichdefinetheaccuracyofhigimedicaldevice
products:truenessandprecision.
Trueness:Thetruenessofmeasurementistheclosenessofagreementbetweentheaveragevalue
obtainedfromalargeseriesoftestresultsandanacceptedreferencevalue.
Precision:Theprecisionofmeasurementreferstotheclosenessofagreementbetweenindependent
testresultsobtained.Inotherwords,whatresultsyoucanexpectifyouweretodorepeated
measurementsusingthesameequipmentwithinshortintervalsoftimeonthesameuser.Theprecision
ofaninstrumentisalsoawayofassessingthedesignandsensitivityofthemeasurement.
Thisdocumentdescribesinsimpletermsthetruenessandprecisionrequiredfromthedevicesonthe
higiStationandtheSH-650HealthStation(HealthStations)to:
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complywithISO13485certificationstandards,and
obtainongoingmedicaldeviceclearancefromtheUSFDAandHealthCanada.
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RegulatoryStandards
InadditiontofollowingaroutineofregularinternalandexternalISO13485audits,higiisrequiredto
certify,viathirdpartytesting,thatitsmedicaldeviceproductsmeetthefollowingstandards:
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IEC60601-1Ed.3.0B:2005,MedicalElectricalEquipment-Part1:Generalrequirementsfor
basicsafetyandessentialperformance
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IEC 60601-1-11 (2010), Medical electrical equipment, Part 1-11: General requirements for basic
safety and essential performance - Collateral Standard: Requirements for medical electrical
equipment and medical electrical systems used in the home healthcare environment
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IEC62366:2007,Medicaldevices-Applicationofusabilityengineeringtomedicaldevices
IEC60601-1-2:2007,ClassBEmissionsEMCandCB
SphygmomanometerGuidanceCollection2010(RevisionDate2013/07/01)
o ISO81060-2:2009,Non-invasivesphygmomanometers-Part2:Clinicalvalidationof
automatedmeasurementtype
IEC80601-2-30:2009,Medicalelectricalequipment—Part2-30:Particularrequirements
forthebasicsafetyandessentialperformanceofautomatednon-invasive
sphygmomanometers
Measurementagainsttheseprescribedstandards,combinedwithconsistentapplicationofourquality
managementsystemprovidesthefoundationforensuringqualityandaccuracyinhigiproducts.
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higiHealthStationDevicesandTests
ThefollowingsectionsoutlinedetailsforeachofthedevicesandtestsdeliveredviaHealthStations.
Note:TheinformationbelowgenerallyappliestoallcurrentHealthStationmodels.Whereinformation
isspecifictoacertainmodel,thecontentwillreferenceeitherthehigiStation,orSH-650HealthStation.
BloodPressureMeasurement
Metrics:Thebloodpressure(BP)testresultsinobservationsforbloodpressure(systolic&diastolic),and
heartrate.
UpperArmCircumference:Thecuffisdesignedtoaccommodateupperarmsizesfrom8.66to17.2
inches(22to43.48cm)incircumference.
BloodPressureAssessment
Foradultandpediatric(children13andolder)patientpopulations,bloodpressuremeasurementsmade
withtheAdvantageOEM(OriginalEquipmentManufacturer)BPModuleSeriesareequivalenttothose
obtainedbytrainedobserversusingthecuff/stethoscopeauscultatorymethodwithinthelimits
prescribedby:
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ANSI/AAMISP10:2002
EN1060-4:2004
ISO81060-2:2013(higiStationonly)
AccuracyRequirement:meanerrordifferenceof±5mmHgorlesswithastandarddeviationof8mmHg
orless.
Providedtheuser’sarmiswithinthedefinedrange,andthedeviceisusedasdescribedintheon-screen
instructions,thebloodpressurecuffiscertifiedtomeettheaccuracystandardrequirementoverablood
pressurerangeof:
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Systolic:78—214mmHg
Diastolic:40—131mmHg
GeneralNotesonBloodPressureMeasurements
Ingeneral,obtainingconsistentBPmeasurementscanbehighlydependentontheuserwhoistaking
themeasurement.Postureisimportant,asiswhattheuserwasdoingbeforesittingdowntotakea
measurement.
InAppendixI,wehaveincludedasuggestedSOPfortakingbloodpressuremeasurementstohelp
ensureconsistencywhenausertakesrepeatedBPmeasurementsoverlongperiodoftime.
HeartRateAssessment
Heartrate(pulse)isrecordedwhentakingabloodpressuretest.Thepulsenumberisprovidedinbeats
perminute(bpm).Thisvalueismeasuredviathesamemoduleusedtomeasurebloodpressure,usinga
methodtodeduceheartratethatisproprietarytothebloodpressuremodulemanufacturer.
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WeightMeasurement
Metrics:Theweighttestresultsinobservationsfortotalbodyweight,andbodymassindex(BMI).
TotalBodyWeightAssessment
MaximumMeasurableWeight:
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higiStation:440lbs(199.6kg)
SH-650HealthStation:500lbs(227kg)
MeasurementPrecision:Weightismeasuredin0.1lbincrements.
Accuracy&Repeatability:ThescalesusedinhigiHealthStationsaredesignedtocommercialand
medicalgradestandards.
Whilethescalesarehighlyaccurate,thesettinginwhichmeasurementsaretakenintroducescertain
variablesthatinfluencethefinalresults(e.g.randomextraweightfromtheuser’sclothes).
Withthisinmind,thefocusforweightmeasurementsisondeliveringrepeatabilitytogenerate
consistenttrendsovertime.Aftereachuse,thescaleisclearedandresettozerotoensurethatthe
precisionofeachuseiswithinthetoleranceof0.1lb.
Asaresult,repeatedmeasurementsunderthesameconditionsshouldnotvarybymorethan±0.1lb.
GeneralNotesonWeightMeasurements
Theweightassessmentisconductedwhileseatedatthekiosk.Forweighttobemeasuredcorrectly:
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Feetmustbeofftheground,andplacedonthefootrest
Handsandarmsshouldnotbetouchinganythingonthekiosk.
Bodyweightmeasurementsincludeanyweightfromclothing,shoes,andanythingtheusermaybe
holding.Thescaledoesnotadjustfortheseitemsandthus,theshownvaluewillbehigherthanthe
user’sactualtrueweight.
Theaddedweightdoesaffecttheresultsofothermeasurementsthatleveragetheweightassessment
duringthesameusersession:BMI,bodyfatmass,andhydration.
Tohelpwiththeaccuracyofthesemeasuresitisrecommendedthatusersminimizethefactorsthat
contributeadditionalweight.Optionsinclude:
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Removecoatsandotherheavyouterwear.
Removeheavybootsorshoes,ifpractical.
Donotholdpurses,bags,keys,orotheritemswhiletakingaweightmeasurement.
Alwaystakeauser’sweightmeasurementsaroundthesametimeofday.
Wearsimilarclothingeachtimeaweightmeasurementistakentomaximizeconsistencyin
trendsovertime.
Asweightandbodycompositionaremostusefulastrendsovertime,themostimportantconsideration
istotakeweightmeasurementsunderconditionsthatareasconsistentaspossible.
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BodyMassIndexAssessment
BodyMassIndex(BMI)isanumberthatiscalculatedusingweightandheight.
Thisnumberprovidesanindicationofbodyfatnessandisusedtoscreenforweightcategoriesthatmay
leadtohealthproblems(CentersforDiseaseControlandPrevention,2013).
Accuracy:AsBMIisnotadirectmeasurement,itstruenessandprecisionisdirectlyrelatedtothe
accuracyofthevaluesusedtocalculateit:
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totalbodyweight(measured)
height(manuallyenteredbytheuser)
TohelpwithaccuracyoftheBMIresult,itisimportantthattheuserenterstheirtrueheight.
GeneralNotesonBMICategories
ThecategoriesdisplayedforBMIresultsarecurrentlybaseduponadultdesignations.
AlthoughtheBMInumberiscalculatedthesamewayforchildrenandadolescents,thecriteriato
interpretthemeaningofBMIisdifferentandthereforetheadultmethodshouldnotbeusedfor
children.
BodyCompositionMeasurement
Metrics:Thebodycompositiontestresultsinobservationsforbodyfatpercentage,andhydration(see
notes,below).
BodycompositioniscurrentlypresentedasanelementoftheweighttestonHealthStationswithan
installedhigibodycompositionanalysisdevice(currentlySH-650HealthStations).
Inadditiontothebio-impedancereadingperformedattheHealthStation,anumberofotherdata
pointsareutilizedinbodycompositionmeasurements:age,gender,andheight.
BodyFatMassAssessment
TheHealthStationbodycompositionanalyzerisbasedonthehigiBC4/BCMhardwareandsoftware.
The510(k)filingforthismedicaldevicewasclearedbytheFDAinJanuaryof2011.Proprietaryhigi
algorithms,baseduponextensivestudies,areusedtodeliverhighlyaccurateandrepeatableresults.
Properuseofthebodycompositiontesthasbeenshowtoresultinreliable,repeatablebodyfat
percentagevalues.
Accuracy:TheaccuracyofhigiBC4/BCMtechnologyhasbeenindependentlyvalidatedinchildrenand
adults(ErcegDN,2010).Resultsofthisvalidationshow:
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Groupaveragepercentbodyfatandleanbodymassweregenerallywithin1percentagepointof
thereferencemethod.
Themajorityofindividualreadingsweregenerallywithin5percentagepointsofthetruebody
fatandleanbodymassvalues.
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Theprecisionofmeasureonaveragevariesbylessthan2percentagepointswhen
measurementsaremadebacktoback,assumingtheusermaintainsthecorrecthandandbody
positionforeachmeasurement.
In2013,theSH-650HealthStationreceived510(k)clearancefromtheFDA.Aspartofthisclearance,
newstudiescomparingtheSH-650HealthStationtothehandheldBC4/BCMshowedthat:
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ThepositionofthebodycompositionanalyzerelectrodesontheSH-650HealthStationprovide
bodyfatvaluesonaveragelessthan1percentagepointdifferentthantheBC4/BCMdevice.
MeasurementsmadeusingtheHealthStationareequallyreliablefromaprecisionpointofview.
GeneralNotesonBodyFatMeasurements
Muchlikeweight,bodyfatpercentageismostusefulasatrendovertime.Usersshouldtrytotake
measurementsinasconsistentamanneraspossible.
Thefollowingcancausefluctuationsinbodyfatpercentageresults:
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Inconsistentbodyorhandposition(inconsistentwiththeon-screeninstructions)
Fluidintakeandmeals(duetotheireffectontotalbodyweight,whichisusedincalculations)
Inadditiontothegeneralguidelinesprovidedforweightmeasurements,thefollowingpracticeshelpto
ensureaccurateandrepeatablebodyfatmeasurements:
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Maintainproperbodyposition,asdescribedintheon-screeninstructions.
Takemeasurementsatroughlythesametimeofday.
Avoidconsumingamealorfluidspriortotakingabodycompositiontest.
HydrationAssessment
Note:Whilehydrationismeasuredduringthebodycompositiontest,theresultsarenotcurrently
presentedtotheuser.Presentationofthisdatawillbeaddedinafuturereleaseoftheproduct.
ThehigiHydrationIndex
DuringthedevelopmentofthehydrationmeasurementtechnologyusedonhigiHealthStations,a
reviewofpublishedworksonhowbesttopresentaperson’shydrationstatuswasconducted.In
addition,higiSHLLCconductedaclinicaltrialonthesubject.Therewasinconsistencyinthepublic
literatureonthebestwaytopresenthydration.
Whatwasclear,however,wastheneedforabetterwaytoreporthydrationresultstousers,sohigiSH
LLCdevelopedtheHydrationIndex.TheHydrationIndexcalculates,onanindividualbasis,aperson’s
specifichydrationstatus.
Higicalculateshydrationasapercentofyourtotalbodyweight,andnormalizesthattoanindividualized
zeropoint(baseline).
Putsimply,theHydrationIndexshowsauser’shydrationstatusrelativetowhatisexpectedfortheir
age,gender,height,weight,andbodyfatpercentage:
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Well-hydrated(positivenumber)
Normal(zero)
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Under-hydrated(negativenumber)
HowItWorks
1. Theuser’stotalbodywater(TBW)iscalculatedbaseduponheight,weight,ageandgenderusing
aproprietaryalgorithm.
2. Theuser’sTBWgoaliscalculatedbasedontotalbodyweight,leanmass,andbodyfat(data
fromthebodyfatcalculation,above).
3. TBWgoaliscomparedtotheTBWactualvaluestocalculatetheHydrationIndex.
Theresultisnormalizedsothatavalueofzerorepresentsnormalhydration,positivenumbersindicatea
well-hydratedstate,andnegativenumbersindicateanunder-hydratedstate.
Thisapproachmakesreviewofauser’sdataovertimeverysimple,aszeroisanabsoluterepresentation
ofnormalhydration,regardlessofotherfactors(weight,bodyfat,etc.).
Accuracy:TheaccuracyofthetwodatapointsusedtocalculateHydrationIndex(totalbodywater,and
bodywatergoal)isplusorminus2%.Theproprietaryalgorithmsusedtocalculatehydrationwere
developedbaseduponclinicalstudiesusingtheHeavyWaterReferenceMethodthatgivesadirect
measureofthewatercontentofyourbody.
GeneralNotesonHydration
Everypartofthehumanbodycontainsfluids.Infact,fluidsarethehumanbody’slargestcomponent.
Hydrationisthetotalamountofwaterandotherfluidscontainedwithinthestructureofthehuman
body,includingbones,muscle,fat,andorgans.
Properhydrationiscriticaltowell-being.Under-hydration,ordehydration,isacommonconditionthat
canresultinimpairedperformanceorday-to-dayconditionssuchasheadaches,poorskinandhair
texture.Anathlete’sperformancecanbeimpairedbybeingunder-hydrated.
Extremedehydrationcanbedangerousandwhenneglected,canresultindamagetomajororgansand
evendeath(Popkin,2010).
Amajorityofthepopulationhasbeenfoundtobeunder-hydrated.Thismaybeduetodrinkingtoo
manycaffeinatedbeveragesthatactuallycausethebodytoexpelfluidsandnothavingenoughdietary
fluidintake.
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AppendixI:RecommendedSOPforBloodPressureMeasurement
Itiswellknownthatbloodpressurevariescontinuouslyinaperson,andcanbeinfluencedbymany
factors.ThefollowingSOPisintendedtohelphealthcareprofessionalsensureareliableandaccurate
readingbloodpressuremeasurement.
Thesestepscanbetakenwhenassistingapatientintakingabloodpressuremeasurement.
1. Removeoutercoatsandsweaters.
2. Askthepersontobeseated,andadjusttheirseatingpositiontobecomfortable.Feetshould
restonthefloor,andbackshouldbecomfortablystraight.
3. Demonstratehowtoinitiatetestingonthetouchscreen,andhavethepersontaketheweight
andBMItestpriortotakingtheirbloodpressure.Alternatively,askthemtorelaxforatleasttwo
minutes(preferablytheAHA-recommended5minutes)beforetakingthebloodpressuretest.
4. Makesurearmcircumferenceiswithintherecommendedsizelimits.Ifitisoutsideofthelimits,
amanualreadingwillneedtobetaken.
5. Havethepersonplacearminthecuff.Ensurethattheelbowisclearofthecuff,andthearmis
relaxed.Ifpossible,thearmshouldberestingonthesurfaceoftheboardwithpalmup.
6. Checkthatthepersonisasuprightaspossible,andnotethelevelofthebottomofthecuff
housinginrelationtothelevelofthesternumonthechest(upperatrialposition).Preferably,
theyshouldbelevelwitheachother.Ifthatcannotbeachievedcomfortably,makesurethatthe
samepositionisusedeachtimeyoumeasurethatperson.
7. Asktheusertopressthestartbutton,andtakethetest.
8. Readtheresults.Iftheyarehigh,itishighlyrecommendedtotakeanothertestaftera90
secondrelaxationtime.
9. Resultscanbemanuallyrecordedfromwhatisonscreen,sentbyemail,orsavedtothe
person’shigiaccountatuser’sdiscretion.
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References
(2003).ISO13485Specifiesrequirementsforaqualitymanagementsystemforthedesignand
manufactureofMedicalDevices.Geneva,Switzerland:InternationalOrganizationfor
Standardization.
(1994).ISO5725-1Accuracy(truenessandprecision)ofmeasurementmethodsandresults.Geneve,
Switzerland:InternationalOrganizationforStandardization.
CentersforDiseaseControlandPrevention.(2013).BodyMassIndex.RetrievedfromCentersfor
DiseaseControlandPrevention:http://www.cdc.gov/healthyweight/assessing/bmi/
ErcegDN,D.-C.C.(2010).TheStayhealthybioelectricalimpedanceanalyzerpredictsbodyfatinchildren
andadults.NutritionResearch,30(5),297-304.doi:10.1016/j.nutres.2010.04.009
Popkin,B.D.(2010).Water,hydration,andhealth.68(8),439-458.doi:10.1111/j.17534887.2010.00304.x
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