On the Job: Redesign Rescues Afghan Maternity Hospital15 Jun, 2005 By: Cadalyst Staff Cadalyst
Scan2CAD raster-to-vector conversion technology speeds effort to overcome crowding and neglect.
An architectural consultant to UNICEF, assisting in the renovation of maternity hospitals at major locations throughout war-torn Afghanistan, has called on the raster-to-vector conversion technology Scan2CAD to help speed his redesign efforts.
In the autumn of 2001, as soon as the Taliban regime was ousted, UNICEF (United Nations Children's Fund) began urgent humanitarian work improving schools and rebuilding and extending hospitals. Afghanistan has the highest maternal mortality ratio ever recorded, 6,500 deaths per 100,000 live births. Recent studies show that in the most rural parts of the country one woman dies every 20 minutes as a result of complications in childbirth or pregnancy. More than 40% of deaths are caused by preventable complications.
Working with the Afghan Ministry of Public Health, UNICEF set out to reduce the maternal mortality rate by providing improved obstetric care facilities to women across the country. The focus of the UNICEF initiative was upgrading Afghanistan's largest maternal health facility, Malalai Maternity Hospital in Kabul (figure 1).
Figure 1. The courtyard entrance to Malalai Maternity Hospital, Kabul, Afghanistan. Like most hospitals in the country, it was in dire condition due more to poor design, overcrowding and lack of maintenance than war damage.
Calling in the Experts
David Potter, a British architect based in Katmandu, Nepal, went to Afghanistan to carry out a consultancy mission for UNICEF. His company, APON (Architectural Projects Office Nepal), specialized in designing affordable community medical stores and clinics in the difficult hill terrain and mountain regions of Nepal.
"When I arrived in Afghanistan, most Afghan hospitals were in a dire condition, due more to poor design, overcrowding and lack of maintenance than war damage," Potter said. "At each hospital, I sketched survey plans and scanned them into my computer. I tried to put these scans into my mission report but I found that in raster format they were too big, difficult to annotate and displayed very slowly on my PC".
Potter called on Scan2CAD, a low-cost raster-to-vector converter from Softcover International, to convert the scans of his sketched surveys into DXF file format for editing in AutoCAD. "This produced much smaller files that allowed me to use all AutoCAD's CAD drawing and editing tools on them. I was able to annotate and add proposed alterations and new extensions with ease. Another great benefit was that I could use the AutoCAD Stretch function to resize parts of the plans where later measurement showed that what I had sketched was badly out of size".
Not a Simple Task
Raster-to-vector conversion is seldom, if ever, perfect. Good results are determined largely by the quality of the paper drawing and its scanned image. As a result, some scans cannot be vectorized with any benefit to the user. Chief among these offending scans are weak and fuzzy photocopies (of photocopies) and drawings that are so scaled down that no clear detail is apparent. Such images cannot vectorize well. This was Potter's experience at one Afghan hospital, which was too big for him to survey in the limited time he had. "Luckily I was able to get a much-scaled-down photocopy of a fairly accurate floor plan. However, the quality of the print was very unclear and impossible to convert well (figure 2). My solution was to trace over the plan by hand with a Rotring pen, then scan it and clean the scanned image to increase its sharpness," Potter said (figure 3).
Figure 2. This is the original "very unclear" floor plan David Potter received. Although its quality might seem reasonable to anyone who understands architectural drawings, raster-to-vector conversion software sees something very different when zoomed into the detail. Users of such technology are wise to zoom into scanned images to determine the actual quality of the scanned image.
Figure 3. This is the scanned image that resulted from Potter's trace of the survey plan. When ink pens are used, ink bleeds into the paper. When scanned, this ink bleed results in fuzzy lines. Scan2CAD tools can remove this fuzziness. However, when a very thick pen is used, as in this example, parallel lines can bleed into each other and cause recognition problems in some areas. A thin pen would give better results.
"Once I had a crisp scanned image, I vectorized it with Scan2CAD (figure 4). I then imported the resulting DXF file into AutoCAD, where I was able to tidy it up, set the correct scale and add room names and my extension design proposals for improvements to the hospital building (figure 5)."
Figure 4. This is the scanned image after it was converted and during the tidying-up process using Scan2CAD's SnapTidy DXF vector-editing tools.
Figure 5. The finished drawing tidied up, scaled and annotated in AutoCAD for submission to UNICEF.
Potter's surveys allowed essential redevelopment work to commence almost immediately. UNICEF and its partners have upgraded the hospital, equipped new delivery rooms, operating theaters and antenatal care rooms and provided a comprehensive training program for obstetricians and midwives. Malalai Maternity Hospital now deals with 200 cases per day and is the largest and busiest maternity hospital in Afghanistan -- and is the first Centre of Excellence in Maternal Health in Afghanistan.
In her easy-to-follow, friendly style, long-time Cadalyst contributing editor and Autodesk Technical Evangelist Lynn Allen guides you through a new feature or time-saving trick in every episode of her popular AutoCAD video tips. Subscribe to the free Cadalyst Video Picks newsletter and we'll notify you every time a new video tip is published. All exclusively from Cadalyst!