Hi,
I have an Ultrasound probe where the seal has gone. The probe failed mains on applied parts when submerged in saline. Can anyone recommend a suitable way of repairing it? It's the seal on the body of the probe rather than the lens cover.
It might all depend on the type of material you are trying to seal and finding a suitable compatible sealant (adhesive). I might be able to suggest a couple but I don't have them to hand at the moment. As I recall some were expensive and cost about £40-50 a tube and were only available from specialist suppliers.
There are also a number of different companies that offer to fix this sort of problem for you and that might be a better way to go but it will cost you.
Thanks for your reply Sonix. I was hoping to fix it in house. The last time we sent a probe away it took over 2 weeks to get it back. The probe is from a Philips HDI5000 if that helps.
The Silicone Rubber Adhesive Sealant that I'd had previous experience of is made by various companies and is known generically as TSE 392C, the tube I have was made by Momentive Performance Materials, Geneva
www.momentive.com although I'm sure it was also made by Dow Corning but if you 'Google' TSE 392C you will find lots of data sheets for it.Its air drying and acetic acid free!
Where I have seen it being used was for sealing two halves of a transducer clam shell together, it was also used to fix the transducer array inside the shell. As it has little mechanical strength itself I'd be careful where and how I used it.
I hope that helps.
I would be careful about sealing in moisture. If it has failed an electrical safety test when putting the proble in saline it means that there was a conductive path inside the probe. Make sure it is totally dry inside before you do any sealing.
Robert
Thanks for your help guys. I spoke to MIUS, they recommend Dow Corning 732. The probe has been sat in a warm place for about a week now so I'll take my chances on it having dried out.
Interesting post this as a frequent maintenance request from our ultrasonographers is to reseal the cable grommet where it enters the probe housing. We haven't come up with a good solution (and I don't mean silicon solution) but it has reactivated interest in finding a suitable adhesive sealant that would do the job. From our point of view it would have to be approved for medical use as some of these probes are used invasively plus you don't want to have any liability issues arising from users, patients or the manufacturer if the product used causes say an allergic reaction or damages other materials used in the probes. We have contacted some manufacturers & supplier & generally they are cagey in either recommending or supplying a product for this purpose & we've been asked to sign disclaimers.SO, if anyone can stand over an adhesive sealant that would meet the above criteria then do let us know.
Cheers
Following on we've been in touch with Dow Corning & they have a product that should tick the boxes - Silastic medical adhesive silicone type A. It has various medical applications including glueing medical devices to patients but of interest to us it's approved for use for medical device assembly & it looks like it sticks to lots of materials - now to find a source of supply.
Nice one, Paul.
Here's the
link (note also the .pdf available on the left).
Regarding a supplier ... have you made enquiries at Dow Corning in Belgium?
Could try
Xiameter they seem to deal with DOw Corning stuff.
Just an update on progress in sourcing the DC Silastic Adhesive - a company called Azelis is the appointed distributor but I suspect they like to deal in DRUM quantities, however, they do supply it but it may take a while to go through a 'qualifying phase'. In the meantime I've found a US supplier who appears to do mail order -
http://www.factor2.com/Silicone_Adhesive_p/a-100.htm - but that's just as much a problem to get. In the meantime I bet one of the hospital departments either use the stuff routinely for procedures or it comes as part of an implant kit, anyone on for finding out?
Has anyone checked with our friendly Gloucester-based ultrasound servicing company?
Maybe they can supply a few tubes of the stuff.
The price of the Silastic is a bit too rich for us - £280 for a carton of 6 tubes 57grams each. Hey-ho, something will turn up.
You could try
Polymer Systems Technology ltd
Unit 6, Vernon Building,
Westbourne Street,
High Wycombe,
Buckinghamshire,
HP11 2PX
tel 01494 446610
Ask to speak to Derek Williams. The trick to an effective repair is a clean joint and proper use of the primer. It may be worth while to drill a small inspection hole in the case. X-ray it first to ensure you are not drilling into any circuitry. Flush out any debris, which is likely to be hardened gel. The silicone has a general cleaning agent which could be used to flush out the debris, through the inspection hole. Use the silicone to seal the joint and the inspection hole.
One way to ensure good flow of the silicone into the body of the probe is to use a vacuum line into the inspection hole. Seal the ends. Apply the silicone mixture, Well mixed ) librally to the joint. Under a vacuum gauge control, reduce and maintain the pressure with a stop valve. You can try this out on some old plastic box first to get the technique right. With the cured silicone drawn into the probe body you should have made an effective repair. Do your electrical safety test with salt water, or just water it doesnt matter.
If you are into repair of ultrasound probes you might want to consider testing them as well.
http://www.northernphysics.co.uk/home/UltraSound_QC.htmlDisconnected elements can effect the quality of your image.