Use Instructions

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RIMS-IFU-001 /Rev.1  Page6/43
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4. PrincipleofOperation
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Theproductisusedtoassistwithanepiduralprocedurethatdetectstheepiduralspacebyautomatically
pushingthesyringebarreltoinserttheepiduralneedleintotheepiduralspace. 
Themotorrotatesbyusingtheelectricpowerofa3Vbattery,andtherotationalmotionisconvertedtoa
linearmotionofthesyringebarrelandtheneedlefixedtothesyringeholder. 
Whiletheepiduralneedleisbeinginsertedintothebody,thepressuresensorinthesyringeholderdetects
thepressurechangebetweeneachtissue.Thedetectedpressurechangeisconvertedandstoredasdigital
dataanddisplayedasagraphonthedisplaydevice. 
When the epidural needle is inserted into the body, the pressure will gradually increase in the
subcutaneous(①)andligamenttissue(②),andthepressurewillrapidlydropwhenitreachestheepidural
space(③).Inthisway,theoperatorscanverifywhethertheneedletiphassuccessfullyenteredintothe
epiduralspace. 
EPIAalsomakesuseofthisphenomenonanddetectsreactionforce,whichismadeagainsttheforcethat
theneedlepenetratesthetissue.Whilethetipofneedleinsertsthroughthesubcutaneousandligament
tissue,thereactionforceaswellaspressureatthetipoftheneedleincreases(①and② inthegraph
below).When the tip of needle reaches the epidural space,the pressureand the reactionforce rapidly
decrease(③).ThepressuresensorofEPIAdetectsthischangeinreactionforceandconvertitasvisualdata.
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Decrease of
∆𝒇
∆𝒕
at ③
indicates epidural space
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