Ultrasound probes - How to identify faults and avoid repairs.
Probelogic Pty Ltd
Ultrasound, Transducer, Probe
For the full article please visit: http://www.probelogic.com.au/component/acajoom/mailing/view/listid-15/mailingid-113/Itemid-130
Most people we spoke to at a recent conference in Hobart asked for advice on how to care for their transducers, which faults are commonly encountered and how they can be avoided.
Users should check regularly for the following points:
Inspect the lens of your probe. Look for any cuts and abrasions. Sometimes these can be very small but should be visible with the naked eye. Lens damage left unattended will result in the transducer crystals being corroded. strain
Inspect the cable bend relief of your probe. Ensure it is not damaged and has not seperated from the probe body. Ensure it is still flexible and not rigid. Rigid or damaged strain reliefs that are not dealt with swiftly can result in cable damage. cracked-case
Inspect your probe case for cracks. Cracks which are not repaired can allow fluid ingress. This will cause corrosion to the probe internals.
Inspect the cables of the transducer visually and by sliding your hand along the length of the cable. Damage often results from cart wheels. Damage that is not dealt with can result in further tearing and wire damage.
View the image of the ringdown from the transducer looking for sections of dropout. To do this, ensure the transducer is wiped clean of gel and is not in contact with any surfaces. Turn up the 2D gain to visualise the ringdown. Ringdown should be uniform across the face of the probe with no dark lines vertically through the image. If you do find dark lines or are unsure, contact us today for further advice.
Inspect the connector to ensure there are no bent or broken pins or signs of corrosion. Also, plug the transducer into the machine and ensure it seats correctly into the socket and latches when the locking pin is engaged. Ensure locking mechanism is not stiff as this will break the latching pin.
The following are the most common causes of damage identified by the ProbeLogic team:
Incorrect cleaning solutions or techniques are used?
The polymers used in the construction of probes will degrade resulting in crazing (spider web cracks). This causes structural damage to the probe case and will eventually result in fluid ingress into the acoustic array cavity. This can result in destruction of the array. Most vendors will not cover this damage under warranty or service agreements.
Probes are left in cleaning solutions beyond recommended times?
The polymers used in the construction of the probes will degrade and will result in swelling of the probe casing. The case will separate from the lens sealants and fluid will enter the acoustic array cavity. This can result in destruction of the array. Most vendors will not cover this damage under warranty or service agreements.
A probe is dropped (even on a carpeted floor)?
Even minor impact will jar the crystal array. The damage is not always visibly apparent but can be detected on a acoustic analyser. If even one crystal wafer is dislodged and fails, then the neighbouring wafers will decay and deteriorate over time. This results in an echo shadow in the image.
A chip appears in the plastic probe body?
As in (1) above, a chip often results in a fracture that penetrates the thickness of the probe case. This provides a path for fluid entry into the probe body or array cavity. Fluid entry may cause excessive electrical leakage and corrosion of the array.
A crack starts to appear between the lens and the plastic probe body? (separation of the lens sealant)
As above, a pathway is created for fluid entry into the array cavity causing a chemical reaction between the cleaning fluid, the crystals and the acoustic matching layer. This causes lens delamination and a build up of Verdigris (green oxidization of the matching layer and shielding) that corrodes and destroys the array.