Mindray XP8-2TU - Thermal Safety; Thermal Limits

TransducerControlsandInspection
Operator's Manual 25
•
Copperoraluminumsheetwithanareaofatleast25cm
2
.
•
Digitalmultimeterwith40MΩscale(calibratedtoNIST).
Bite-hole Test
1.
SubmersetheTEEtransducerwiththeendoscopeshaftinliquidtoabovethe40cm
mark(butbelowthehandle).
2.
Connecttheleadsofthemultimeter,seeFigure 3-4.
Themultimetercanbeconnectedtotransducerandcopperoraluminumsheetusing
alligatorclips.
–
Connectthepositiveleadtothebaremetalofthesystemconnectorhousing.
–
Connectthenegativeleadtothecopperoraluminumsheetinthesalt-waterbath.
3.
Setthemultimetertomeasureresistance(range>40MΩ).
4.
Waitatleast2secondsandverifythattheresistanceisacceptable(greaterthan10
MΩ).
WARNING
●
To avoid injury to the patient, do not use the transducer if the resistance value is
lessthan10MΩ.Endoscopeinsulationmaybedamagedandshouldbeverified
by a Mindray representative.
●
To avoid injury to the patient, Mindray recommends that leakage current
measurements be carried out on a regular basis. In addition, a bite-hole
inspection should be conducted prior to the use of the transducer in any surgical
procedure.
3.4 Thermal Safety
Maintainingasafethermalenvironmentforthepatienthasbeenadesignpriorityat
Mindray.Itisgenerallyagreedthattoavoiddamagetobodytissues,forlongterm
exposures,tissuecontacttransducertiptemperaturesshouldbelessthan43°C.The
ultrasoundsystemincorporatesanelaboratethermalsafetysystemwhichinformsthe
physicianoftheoperatingtemperatureofthetransducer,andpreventstheoperative
temperaturefromexceedinggivenlimits.WhenevertheTEEtransducerisconnectedtothe
system,thetransducertiptemperatureisalwaysonthesystemdisplay.
Ifthetemperaturesensorisnotworkingproperlywhenyouconnectthetransducertothe
system,thetransducerwillnotbeacceptedandscanningwillnotbepossible.
3.4.1 Thermal Limits
Thesystemhastwolevelsofupperthermallimit:thersthighlimitissetat41.0°C,and
thesecondhighlimitissetat42.5°C.Ifthetemperatureofthetransducertipreaches41.0
°C,thetemperaturedisplayturnsred.Ifthetemperaturereaches42.5°C,thesystemwill
freezeunconditionally(thesystemcan’tbeunfrozenevenbyusingthe
Freeze
key).The
userwillnotbeallowedtoscanuntilthetemperaturehasdecreasedbelow42.0°C.To
restartscanning,theusermustpresstheFreezekey.
Thesystemhasalowerthermallimitof17.5°C.Ifthetemperatureofthetransducertip
reaches17.5°C,thetemperaturedisplayturnsred.