IEC TS 63070-2019 pdf free.Ultrasonics – Field characterization – Infrared imaging techniques for determining temperature elevation in tissue-mimicking material and at the radiation surface of a transducer in still air.
Measurement of the temperature inside a phantom is one goal for observations by the lR-camera.So one of the most important requirements of the phantom is its ability to be split intotwo pieces of TMM with flat (or slightly convex) cross-sectional surfaces that can be exposedto the IR-camera. TMM is vulnerable to dehydration and mechanical damage. A practicalphantom may be kept in a rigid housing in order to avoid dehydration and malfunction causedby cracking the TMM during the operation of combination and separation during themeasurement procedure.See Annex A.
The TMM should have acoustic and thermal properties that mimic the appropriate tissue ofthe human body.The emissivity of the split surface should be known.One of the applicablematerials equivalentto softtissue isspecified in IEC 60601-2-37:2007 andIEC 60601-2-37:2007/AMD1:2015; its emissivity was determined in[7] to be 0,94 bycomparison with black body tape.
Minimizing multiple reflections of ultrasound between the transducer and the bottom surfaceof the phantom should be taken into consideration. Lining material,which is used in othercircumstances to absorb ultrasound propagating in a water tank and has a high attenuationproperty,may be appropriately placed at the bottom of the phantom to be effective for thispurpose.Bone-mimicking material or sterilized bone fragments [8] [9] [10] should be used asnecessary with soft-tissue mimicking material.
lf high temperature rise is expected in the TMM,such as when heating with a HITU system,then the properties of the TMM should be known and stable,over the range of expectedtemperature rises during the measurement.
7.2Periodic validation
Periodic validation should be performed from the viewpoint of both acoustic and thermalproperties. The specified values of attenuation coefficient,thermal conductivity and heatcapacity in lEC 60601-2-37:2007 and lEC 60601-2-37:2007/AMD1:2015 should be maintainedwithin the specified tolerances.The period between validations should be one year.
The replacement with new split TMM phantom should be considered when the structuralabnormality like cracks andlor the degradation like change of colour are found by visualinspection.
The properties of the selected tissue-mimicking phantom should be appropriate to the tissuebeing simulated and the purpose of the measurement.IEC TS 63070 pdf download.