Tuesday, November 4, 2008

SLDF now exists more than 10 years and I thought it's time to offer a discussion platform for all users of this wonderful measuring instrument.


So, I invite you to ask your questions, report your findings or - what's the main purpose - discuss.


Some words about the past of SLDF: In 1995 I started the development of a software for measurement data made by the Heidelberg Engineering Retina Flowmeter HRF.


Making a new software was necessary because the original software by HE was only a prototype with the ability to make these great 2D images of the retinal perfusion. But the software did not provide a reasonable way to analyse the data. The 10x10 (or bigger) moving rectangle analysis method was error-prone and far away from being observer-independent or reliable.


So I started implementing algorithms that provide reliable results. A colleague, Istvan Pal, provided some basic parts of the vessel recognition which I adapted and improved. And my colleague Dr. Harazny - Diploma Biologist - was (and still is) perfect in making good HRF images and could (and still can) do also complex database queries plus statistics in the twinkling of an eye :-) She also helped to improve the user interface as she was "my beta tester" sitting at the next desk. By the way, that was my first experience in "extreme programming".


Together we could evolve the algorithms and add more and more ways to analyse the HRF images.


Today SLDF can



  • analyse flow/pulsatility/cumulative frequence of RIM, temporal and nasal regions (plus a freehand aread)

  • perform vessel cross-section analysis

  • create scatter plots

  • create time plots, histograms, co-occurence plots, cumulative frequency plots

  • perform vessel wall thicknes analysis (an extension I made for Prof. Dr. Schmieder/Erlangen)

  • finally also visualize the results on a printout

For installation CDs (standard and extended versions) please contact Prof. Dr. R.Schmieder (Roland.Schmieder@uk-erlangen.de).

2 comments:

Peter Lewis said...

Is the Heidelberg doppler flowmeter still available for purchase? I have visited the UK, USA and German pages of Heidelberg engineering but can't find the flowmeter in their product-lists. Approximately how much does such an instrument cost?

Kind regards,

Peter

Dr. J.Welzenbach said...

Heidelberg Engineering does not produce new HRF instruments. (Main reason is lack of PC hardware components and main boards).

If you're interested in doing research or studies with HRF and SLDF software I recommend you to contact Prof. Dr. R. Schmieder (Roland.Schmieder@uk-erlangen.de).