TransducerControlsandInspection
22 Operator's Manual
– Connectthepositiveleadtothebaremetalofthesystemconnectorhousing.
– Connectthenegativeleadtothecopperoraluminumsheetinthesalt-waterbath.
3. Setthemultimetertomeasureresistance(range>40MΩ).
4. Waitatleast2secondsandverifythattheresistanceisacceptable (greaterthan10
MΩ).
WARNING
●
To avoid injury to the patient, do not use the transducer if the resistance value is
lessthan10MΩ.Endoscopeinsulationmaybedamagedandshouldbeverified
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
Maintainingasafethermalenvironmentforthepatienthasbeenadesignpriorityat
Mindray.Itisgenerallyagreedthattoavoiddamagetobodytissues,forlongterm
exposures,tissuecontacttransducertiptemperaturesshouldbelessthan43°C.The
ultrasoundsystemincorporatesanelaboratethermalsafetysystemwhichinformsthe
physicianoftheoperatingtemperatureofthetransducer,andpreventstheoperative
temperaturefromexceedinggivenlimits.WhenevertheTEEtransducerisconnectedtothe
system,thetransducertiptemperatureisalwaysonthesystemdisplay.
Ifthetemperaturesensorisnotworkingproperlywhenyouconnectthetransducertothe
system,thetransducerwillnotbeacceptedandscanningwillnotbepossible.
3.4.1 Thermal Limits
Thesystemhastwolevelsofupperthermallimit:thersthighlimitissetat41.0°C,and
thesecondhighlimitissetat42.5°C.Ifthetemperatureofthetransducertipreaches41.0
°C,thetemperaturedisplayturnsred.Ifthetemperaturereaches42.5°C,thesystemwill
freezeunconditionally(thesystemcan’tbeunfrozenevenbyusingtheFreezekey).The
userwillnotbeallowedtoscanuntilthetemperaturehasdecreasedbelow42.0°C.To
restartscanning,theusermustpresstheFreezekey.
Thesystemhasalowerthermallimitof17.5°C.Ifthetemperatureofthetransducertip
reaches17.5°C,thetemperaturedisplayturnsred.
WARNING
To avoid the risk of esophageal burn for adult patients, reduce the time spent
imaging at distal tip temperatures in excess of 42 °C (107.6 °F). Exposure should be
limited to 10 minutes or less at 42 °C (107.6 °F) or higher. There is no sufficient data
to prove the thermal tolerance of the esophagus in neonate and pediatric patients,
but it is apparently these patients are more vulnerable than adults. Reduce the time
spent imaging at distal tip temperatures in excess of 41 °C (105.8 °F).