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Who I Am
As I am a polite person, I will first introduce myself . My name is Manuel
Soriano, I work as a consultant and my passion is Linux.
I was not always a consultant, I studied at the Polytechnic of Geneva
/ Switzerland, and I must say in those years there were no Linux, Bill
Gates, Intel, etc.. The truth is that computers used to occupied complete
floors, he who had 32K of memory RAM (yes! 32K, K of Kilo) was a rich man,
especially if that was coupled with 20MB of hard disk and one or two magnetic
tapes.
In such a peculiar environment, about 200 of us gathered near the stairway
that gave access to the computer center, with our programs (FORTRAN) in
punched cards. The atmosphere was hallucinating. When you had access
to the card reader it was a magical moment, it read the cards, and after
5 or 6 minutes of waiting the printer spit out its verdict, almost always
GUILTY!. Then it was time to fix the wrong statement and return to the
queue.
Well all this is just to let you know I am not 20 years-old and that
I have spent a few years in this business of byte and bit, with or without
parity.
Discovering Linux
There have been two great events in my professional career. A Z80
multi-processor machine (yes, you read it correctly) with UNIX (3.0) but
Unix from ATT and sixteen years later.... Linux.
I was coming from huge and powerful machines (Control Data Cyber) with
zillions of megas of hard disk, tons of memory, innumerable
users thirsty for CPU time. One day someone comes and shows me a CROMEMCO
(my first micro). Surprise! It had an operating system whose name was:
Unix, what is that?
I kept it. Later in time I learned about other things, VMS, VM,
AIX, PROTEUS, MS.DOS (and its sequel), UNIX ATT 4.2, etc...
For my spare time I acquired a 386 and installed on it a UNIX ATT 4.2
with X11(R3) and Motif(1.0), but in certain magazines there were already
advertisements of a version 5 of X11, Motif 1.2.4 and an operating system
(UNIX) that cost 50 US dollars. Well, those of you with working experience
in SCO or any other, will know what their licenses cost. I invested 250
US dollars on the purchase of that OS and Motif. It arrived after a month.
It was a Yggdrasyl with kernel 0.95. I gave it a whole hard disk
first, later all the computer, and finally my professional life (and I
do not regret it).
Evaluating Linux
"Yes man it works!", "Believe me!, with X11R5 and MOTIF 1.2.4, it doesn't
hang up and my RESET button is accumulating dust due to lack of use". This
is what I told a Swiss friend of mine when he called me to Spain. He was
exploiting Solaris, X11R4 and Motif 1.1 for PC's, each license cost him
no-more-no-less than 8,000 US dollars and he was looking for something
"more economic". I mentioned Linux to him. He did not hang up the phone
on me because of our friendship but he indeed alluded to something
about "being drunk". Nevertheless, he bought it.
This good man has a company (DAPSYS SA.) devoted to healthcare informatics.
His specialty was storage and retrieval of radiological images for screen
devices, either with X11 or Motif or Win95. After trying Linux for few
days (15) he adopted it, sending to the garbage 2 AIX, 1 HP800 and 1 DEC
with Ultrix. Today he is a happy man with a "portable" and his Linux.
This company already had a few installations in Switzerland when a great
opportunity presented itself in Canada. Almost without warning two salesmen
from a large American company showed up. They were not coming to sell something
but to check "something" that "someone" mentioned to then at the RSNA in
Chicago. The RSNA is the world event in the subject of radiology. Two months
later the director of DAPSYS went to Montreal with his "portable" to demonstrate
the product to several doctors; three months later (504 years after Colon),
I'm off to the Americas to perform the first installation in that
continent of Iris. Iris is an application for the archival and retrieval
of radiological images.
This first installation clearly showed the robustness of the product,
of which Linux is great part, and that we could handle the problem correctly.
St. John
All that to get here, to what interests us: the INSTALLATION. But first
let me explain the specifics of the problem.
Radiology is a specialty that is usually very expensive both in equipment
and in film stock. This last item can take 15 to 20% of the annual budget
of any radiological department. For this and other reasons it was desirable
to eliminate film usage and substitute it for a computer screen.
Furthermore, Iris allows one to centralize ALL the radiological events
by patient. Each image has recorded in it the first and family name and
patient code. Iris permits retrieval of this information through
OCR techniques, extracting this data and archiving it together with the
existing images of the patient (in case there are any).
Iris not only saves in film expense, but it also saves storage space
(Hospitals must archive the images for all its patients for years), images
can be shared simultaneously among several physicians kilometers away (even
with an ocean in between), and they can be searched very rapidly.
In the anglophone part of Canada there is a tendency to centralize healthcare
in phases; first regionally and then at the provincial level. Each
province has a certain independence and the province that hired us for
this first installation has seven regions.
In this region we are going to connect six hospitals though a WAN ATM
of 100 and 10 Megabit, Linux has nothing to do with this network, it only
works on it, but it allows us to stress the importance of its tasks.
The headquarters for the whole system is located at St. John hospital.
It has two archives, the first one has the following specs:
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1 Pentium Pro 200Mhz
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112G of Hard Disk
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1 DAT robot with 200G in tapes
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1 Network card 10Mb
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1 Network card 100Mb
The second one is identical but with "only" 27Gb in St. Joseph.
In a first phase the network will consist of six hospitals, with two
more being added during the second phase of the project. In the first phase
we are going to connect the following:
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4 stations X11 with double screen for diagnostics in the hospitals themselves.
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12 stations W95 for examinations in various hospitals.
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17 stations W95 for doctors outside the hospitals.
To the backbone of the hospital's system will be connected all the doctors,
radiologists or not, who wish to send their patients to the state hospitals.
What is Linux doing in a Hospital ?
Right, why Linux?.
In the healthcare environment Linux has an incomparable strength: its
price and the type of hardware it uses.
For the same functionality the final cost usually is about 50% or less
compared to Sun, HP, IBM or DEC stations and Linux functionality has nothing
to envy in the others.
The saving on Linux allows hospitals to install a larger number of stations
and more hardware throughout the hospital and it allows them to increment
its services, which in Canada are not public but semi-public. The
hospitals are regional and depend on the regional governments, but their
budgets are only partly supported by the regional tax-payers. The
other part comes from the services provided to local establishments. Linux,
therefore means better and more services for less costs and more income.
It also means that hospitals can pass down to smaller clinics and patients
the savings and can stay competitive.
With regard to the robustness of Linux , all I have to say is that
I have a server with a record up-time of 26 months.
Nobody and that means NOBODY, has given us any objections to using Linux
for the installation. What really counts is the solution and that the solution
WORKS. This concept is very far from the old idea of setting up an
operating system (with a known name) as a solution and then a program that
sharpens that solution.
The truth is that we have not had any problems putting Linux into the
various hospitals, or suffered any funny comments. On the contrary I have
detected a certain respect with regards to the word Linux, but for some
reason, this system seems to be most supported in the USA rather
than Canada (although this may appear strange, because Canada is, in a
sense, like the USA).
What are those two servers doing?
A radiological image usually has a size from 256x256x1 to 8192x4096x2,
which means it takes up a lot of storage space and so will only hold up
to 6 months worth of information. After this time, the study of a
patient passes to a different support (non mobile), and for the moment,
on to DAT tapes. In the future we will most probably change to magneto-optical
robots of 600Gb.
The topology of the network is very simple, for each hospital:
1) Ethernet of 10Mg/bits for
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- Radiology Halls
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- Iris Servers (2)
2) Ethernet of 100Mg/bits for
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- Iris Servers(2)
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- Visualization Servers
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- Router to the WAN of the remaining hospitals and network of medical services.
For understandable reasons, the radiological equipment is not in contact
with the hospital network. The Linux servers are in charge of retrieving
images, archiving and serving them to the visualization stations that require
them.
In a server
For a given patient several X-ray explorations can be presented in various
modalities. An exploration is a radiological exam, each exam may have one
or more X-ray images or shots. A modality is a device capable of producing
radiological images by means of X-rays, ultrasound, NMR, etc..
When the images are shot, they arrive directly to the server which has
to be capable of "reading" the image and extracting the patient data in
order to forward it to the visualization stations and archive them with
the other patient data.
Before archiving an image, it goes through a process of "clean up" and
non-destructive compression. We now achieve compression ratios of 60%.
We could achieve higher ratios, but it would be at the expense of performance
in the archival process and later restoration of the images.
According to the tests performed, an image of 512x512x2 takes 0.3 seconds,
on average, to appear on the computer screen from the beginning of the
transaction. I speak of averages because a study is not always a single
image, this average can be improved both by means of hardware and by improving
the method of retrieval.
St.John has 12 halls producing 1,000 images per day, this gives us an
idea of the volume the servers must handle. During the test period we were
reaching the CPU usage of nearly 2%, with 6 halls sending images.
In a client
This is the easy part, there are three types of clients:
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SGI workstations
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IRIS/Motif workstations
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IRIS/Win95 workstations
The SGI receives the images that "bounce" on the servers. This way
the radiologists have at their disposition the images of the day. These
stations are not ours, nor Linux and the stations have 2 screens
of 20 inches each.
The workstations IRIS/Motif are, mainly, for visualization work with
diagnostics. Since they can pilot up to 4 screens, but for the moment they
only have two screens of 20 inches each. The searches of the database can
be summarized by:
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- Patient Data
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- Exam Date, Patient birth date
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- Modality
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- Pathology
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- Keyword
The IRiS/Win95 workstations perform the same task than the Motif stations,
except that they usually are installed on existing material and are only
good for supporting diagnostic work and not for diagnosis itself.
Conclusion
To finish, I can only say that this system has as much room for expansion
as any other OS. An Operating System is only the support, and this support
can be good or bad. The success of the solution depends upon the system
and the application being able to work together.
Lately someone in a magazine has managed to spread the idea that the
solution for a problem stops by his favorite OS, but if we are good professionals
we must be able to convince people that WE know better than any journalist
what works or not.
Have fun with Linux...
Bye
Manu
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