Backward-Chaining Rule-Based Systems. Elnaz Nouri December 2007. Chapter 7 overview:. Introduction Medical consultation systems Example 1:Meningitis Diagnosis Expert System Example 2:Meningitis Prescription Expert System Example 3:Alternative Prescription Expert System
Prove or disprove “Infection is meningitis”
This can be proven if the user already knows that the patient has meningitis or the system can infer it.
SYSTEM: “After considering your info, I believe the infection is Menningitis.”
- The rules are shown in next slide.
- We have one goal to prove :
“Prescription is ? Prescription”
GOAL : Determine proper series of drugs
SYSTEM : “My first recommendation is this :
Ampicillin --- Dose : 3.8 g
Gentamicin --- Dose : 131 mg ”
SYSTEM : To drive goal ”Prescription is ? Prescription” I considered:
-RULE1(1.1 is known to be true)
-To drive 1.2 I considered RULE3
-To drive 3.1 I asked you. your answer was 8.
-RULE 3 was concluded.
-RULE 1 was concluded.
- Using existing knowledge
- Using general knowledge
- Determine problem area
- Determine specific fault
USER: won’t start
USER: does turn
USER: normally but won’t start
USER: does move
USER: star occasionally
The specific problem is DIRTY CARBURETOR.
My recommendation is REBUILD THE CARBURETOR.
The cost for such repair is 100 dollars.