Helen,
Most of the older theatres in GRH are fitted with Vistamatics on the main doors, and I recall having a meaningful discussion with the HSE inspector a few years back about the safety of these 'hit-and-miss' windows, which are constructed of overlapping panes of glass which can be moved so that the stripes of opaque (frosted?) glass can be be aligned out of phase to obscure the window, or aligned in phase, as it were, so that one can see through the coincident gaps. The HSE inspector argued that they were a laser hazard, but I argued that while they represented a small but finite risk of an escaping visible beam, they were a better option than someone actually opening the door, to see if Dr X was in theatre, or Sister Y was on duty. Vistamatics can be ordered with laser-resistant filters for certain wavelengths, but this is not a fail-safe option obviously, since other wavelengths may be used in the same theatre, and they appear not to be retro-fittable, so that even that option becomes expensive if plain glass Vistamatics are fitted, since they can be only be replaced completely, not a popular suggestion under financial constraints.
I still maintain that the risk of the Vistamatic being opened briefly at the same time as a laser beam strike hits the door is low, and can be warned against with suitable signage outside the door, abut that it is preferable to sticking your head round the door to see who is operating.
Our newer theatres are not fitted with such inspection windows, but this introduces the alternative risk of having to enter the theatre. As always, the Risk Assessment is the key; if you are aware of the risk, and do something about it, you should be able to justify their presence. If you can't justify it, there's always the option of an obscuring panel that covers the window and avoids the issue altogether. But this may start the discussion about door-locking instead, another knotty problem area that is largely defined by the views of our Fire Safety Officer - but that's a different discussion.
David.
______________________________________________________________________
David Taylor, MA CPhys MInstP MIPEM - Consultant Medical Physicist ([log in to unmask])
(previously Head of Non-ionising Radiation Physics / Laser Protection Adviser)
Medical Physics Department, Leadon House
Gloucestershire Royal Hospital, Great Western Road
GLOUCESTER, GL1 3NN, UK
Tel: +44 (0)8454 225976
Fax: +44 (0)8454 226489
Past Secretary/Treasurer - British Photodermatology Group (www.BPG.org.uk)
______________________________________________________________________
-----Original Message-----
From: British Medical Laser Association on behalf of Helen Amatiello
Sent: Tue 1/7/2014 10:44
To: [log in to unmask]
Subject: Vistamatic blinds
Dear Mailbase
I wondered what fellow LPA's take on the use of Vistamatic blinds were please?
These are sandblasted frosted glass panels that seem to be very popular for use in theatres and other locations.
I have made some rudimentary transmission checks on samples and they seem to have ~80% transmission in 280 to 800nm range that we are able to test. I do not think that this takes any account of any diffusion of the source that the sandblasting may have though.
Do LPA's use these in their locations? And if so, are other control measures put in place?
Many thanks for your responses in advance,
regards
Helen Amatiello
Clinical Scientist/Radiation Protection Adviser
*****************************************************************************
The information in this email and in any attachment(s) is commercial in confidence.
If you are not the named addressee(s) or if you receive this email in error then any
distribution, copying or use of this communication or the information in it is strictly prohibited.
Please return it to the sender and delete all copies. Thank you.
Whilst e-mail and attachments are virus checked Gloucestershire Healthcare Community
does not accept any liability in respect of any virus which is not detected.
Please note that any views or opinions presented in this email are those of the author
and do not necessarily represent those of their respective organisation.
2gether NHS Foundation Trust : http://www.2gether.nhs.uk
Gloucestershire Care Services NHS Trust : http://www.glos-care.nhs.uk
Gloucestershire Clinical Commissioning Group : http://www.gloucestershireccg.nhs.uk
Gloucestershire Hospitals NHS Foundation Trust : http://www.gloshospitals.org.uk
*****************************************************************************
|