# Semi-Automatic Adaptation of Diagnostic Rules in the Case-Based Reasoning Process
## 2 Materials and Methods
### Decision Support System (DSS)  
DSS is an interactive and flexible computer system that helps subjects make decisions and solve various types of problems. There are many types of DSS, but for the medical field, the most well-known are knowledge based DSS, also called expert systems (ES). These systems are equipped with the knowledge of an expert a specialist in a specific area (the knowledge base), and an inference mechanism able to derive valid conclusions based on the input information and the knowledge base. As a result, ES can propose solutions similar as the human expert would do.  
In recent years, the use of DSS in the healthcare domain has increased. The systems assist medical staff in day-to-day decision-making processes such as diagnosing one or more diseases, proposing appropriate treatment, diagnosing the absolute absence of some illness, or looking for their causes. Older expert systems were designed to handle only one problem [23; 24; 25], such as heart disorders [26]. Current expert systems already cover a wide range of medical issues, from diagnosis and response to test results to prescribing drugs for various diseases [27].  
The first medical expert systems have existed since 1960 [23; 28; 29] and are still being developed with gradual improvements for today. Typical representatives of these systems are DENDRAL [24]--its primary goal was to study the formation of hypotheses and discoveries in science, which resulted in a specific task: to assist chemists identifying unknown organic molecules by analyzing their spectra using knowledge from chemistry. MYCIN [23]--its main task was to help doctors identify bacteria causing serious infectious diseases and to recommend treatment with antibiotics at a dose adjusted according to the patient's body weight (the name MYCIN derived from antibiotics with the suffix \"-mycin\"). MOLGEN [25]--the best-known ES in genetics, provides an intelligence consultant to a molecular geneticist in designing experiments, including DNA treatment. INTERNIS-1 [30]--is an educational project developed at the University of Pittsburgh in the early 1970s. This system aimed to assist healthcare professionals in the diagnosis of diseases in general internal medicine. The Expert Disease Program [26] focused on treating heart disease. It allowed the physician to write-in information about the patient's history, physical examination, and laboratory tests, and then generate a detailed explanation of the differential diagnoses indicating the clinical data that support each diagnosis of heart disease. PUFF [31]--expert system PUFF (Pulmonary Function System) diagnoses the results of a pulmonary function (PF) test, such as lung volume, the patient's ability to move air to and from the lungs, as well as the lung's ability to get oxygen to the blood and carbon dioxide. The result is a set of interpreted patient statements and diagnoses. Other expert systems include, for example, ONCOCIN (aimed at treating patients with chemotherapy), or TRAUMA Advisor, whose primary role is to help clinicians in rural areas in the diagnosis and treatment of trauma patients with head injuries. The work of [PERSON] et al. [32] provides a brief overview of medical diagnostic expert systems based on already existing studies.