5GL Doctor

Purchase and Download 5GL-Doctor Displays Architecture

Medical Diagnosis Expert System(s) - Professional Editions Page(s)
(A Diagnosis Aid for Heath Care Professionals - for Windows computers - any Windows version, even 64 bit version available)

Large database, matching symptoms/signs/labs using expert system mathematics

5GL-Doctor is a large medical database. An inquiry consists of symptoms and signs and lab results. This is matched against known conditions and a short list is produced (the database is so large this is rarely a short "short list" but there are options to focus the resultant short list). The matching is performed using a number of mathematical like "expert system" functions. Thus say we have the inquiry "facial paralysis, poor horizontal gaze, tingling sensations in left side of the body". The expert system modules use various combinations in an attempt to find the disease pattern that best satisfies the inquiry. How common a disorder is enters the equation. History can enter the equation. Lab results can enter the equation (however, there is a function just for lab results). Physicians who use it tend to comment that the software is a memory aid usually listing a huge number of potential conditions in response to an inquiry. For most physicians, that is precisely all that is required and the skill of the physician can focus on the items more relevant.


Click on images for larger version

Not just diseases - drugs and labs database, in particular those aspects of value to physicians. Different functions even finding a condition closest to a given condition. All conditions are defined as symptoms/sign patterns in the database. The symptoms/sign list contains about 9000 items.

If all else fails, do not forget the search functions!

In brief:
- USA or British English supported, select at installation time
- large database (information from Harrisons, Merck, e-medicine, to name a few. However, most of the wording is slightly changed because the software is a highly intelligent program that scans entries during a process known as the building of a Compilation Matrix, and puts together intelligent insights into a particular condition. Thus, it needs specific wording in some cases to pick up the intelligent insights.)
- about 9000 symptoms/signs/labs predefined
- about 4000 disease entries (but in some entries there are 20 or more variations or combinations)
- known aliases or other names of a condition included, in some cases this is a large list in its own right
- different diagnosis functions including based on history alone or labs alone
- typical operations: find the most appropriate symptoms/signs from the Selection List, select, and click on the doctor's icon, later select relevant patient history from a list
- some warnings are provided should symptoms/signs satisfy an "emergency" condition
- the database is completely updateable and so are the "expert system" rules which means, for example, you can introduce as many warnings as you like
- there is a conversation compiler in the software. Two versions of the software are available, one for physicians and nurses and allied professionals, the other for personal use. The conversations are intended for the personal user however such can be used to design diagnosis algorithms as well. These are included in the professional editions as examples of how to define conversations.

5GL-Doctor Displays

There are a number of functions. A drug database and a medical procedures database are also included. One function will list all similar conditions to a given condition. Another function will look at history alone and produce a short list. Another function "simulates" a condition by assuming one symptom/sign is incorrect and then manipulates possible conditions and produces a short list. While there is an extensive tutorial, you probably will never read it because it is easy to use - unless you want to design "conversations" which can be even used to tally specific symptoms/signs/history in order to differentiate between various conditions. Some entries are more "generic" and there to point you in the right direction more so than providing a diagnosis. You can make an analysis using exact and precise symptoms/signs or use symptom groups. With a huge symptoms/signs list of around 9000 entries, you can usually find an exact and precise symptom/sign be such specific such as "flesh colored lesion on finger" or more general such as "chest tightness". You can add any new symptom/sign or rename ours if you find a particular definition not as good as it could be.

Sample of the large selection list (it just goes on and on; while medical names are also used, the software is also purchased by non-medical people hence the decision was made to define symptoms/signs in such a way that non-medical people can find the most appropriate and correct symptom/sign)


Click on images for larger version


Click on images for larger version


Click on images for larger version


Written in Visual Basic. Available for 64 bit machines as well as 32 bit. Any Windows version. Note that Windows "clones" to date have not been able to cope with the size of this software.

A large database is the foundation. Every medical condition is defined using a "symptom/sign" pattern, sometimes with labs. The latter not that important because there is a distinct lab analysis function.

Important to understand is that it is not only medical professionals who purchase the software - a person with a serious condition may also purchase. The latter group was a larger market initially and for this reason the decision was made to use as simple a description of a symptom and sign as possible (but there are aliases that map each symptom/sign onto proper medical names too). There is an "explanation" capability too hence any term  not clear can be "explained".

The inquiry, consisting of symptoms and signs and other keys, is matched against the disease pattern. The matching is mainly mathematical type using what are called ESDPs (expert system decision process). Each ESDP considers different aspects of how well the matching satisfies. One ESDP may consider how common a conditions is. Another how many others are sufficiently similar hence the likely "error" in the short list. Another might go through the top short listed entries and then scan a differential diagnosis table and adjust the "measure values" on the short list.

There are a number of analysis functions. Note that a few are only suitable for large displays (say 21 inch) because the information is not going to fit onto smaller displays (but with most laptops this does not matter nowadays as you can make the display smaller).

The symptoms/sign selection list is simply huge with any variation you can think of likely being on the list. Anytime you add a disease entry, you can either also add new symptoms signs or these will be picked up and understood during the Compilation Matrix building.

Some ESDPs attempt to imitate the thinking of an expert in medicine. Such put emphasis on certain keys or the sequence of presentation of symptoms and signs.

The software is also a partial compiler. It can compile code into conversations. This was developed for the Personal Edition but also left in the professional editions. That code is easy to put together and explained in the comprehensive tutorials. However, some features of the compiler are used at many levels thus suddenly a compiler message might come up warning about a conflict, or that the best result (from the "compiler's" point of view) is in fact not on the top short list, etc. This option can be switched off because it can be a nuisance if you are refining a particular inquiry and do not want to see all the warning or information messages again. (the image library is also shared by the personal and professional editions, which means some images are basic).

Perhaps the biggest weakness is the fact that as many conditions as are defined, medicine is still a large field and there are ever so many extremely rare conditions. How many of these does the database know about? No way to be certain - but when Medscape sends us new cases studies, such often also contain extremely extremely rare situations and so far about 50% of these are not on the database (that is, are added as they come to light and available in each new version, but of course you can add these yourself very easily).

The medical database can be replaced with any other database and the expert system technique used against it. This could be useful for perhaps researchers who wish to put together a specific database.

Purchase and Download

5GL-Doctor Professional.
Two activation codes supplied which means you can install on your laptop as wel.
After purchase come back to this page and
Click to download 5GL-Doctor Professional Edition for 32 (the vast majority) bit machines

5GL-Doctor Professional Expanded.
This edition contains more analysis functions and a slightly larger database as well as improved matching in more complex situations.
Two activation codes supplied which means you can install on your laptop as well.
After purchase come back to this page and.
Click to download 5GL-Doctor Professional Expanded Edition for 32 bit machines (size 18 MB)

Click to download 5GL-Doctor Professional Expanded Edition for 64 bit machines (size 18 MB)