A FUZZY EXPERT SYSTEM DESIGN FOR ANALYSIS OF SOUNDS PRODUCED BY THE HUMAN BODY & DESIGN OF AN UNIQUE ELECTRONIC STETHOSCOPE

B.HEMA KUMAR Under the guidance of Mr.G.BALASUBRAMANIAN Senior Lecturer, Biomedical Signal Processing & Instrumentation SASTRA Deemed university

 FES for heart sounds, lung sounds, intestinal sound analysis  Design of an electronic circuit to detect and amplify sounds from human body.  Comparison of electronic stethoscope with conventional stethoscope.

SOFTWARE Twenty volunteers and twenty patients in each category (for cardiac sounds, lung sounds and intestinal sounds) randomly selected with different age, sex and clinical symptom, who were referred to the outpatient department of a major hospital. Auscultatory findings were given to the engineer for designing a FES for each category of cases. Fuzzy expert system design was done using fuzzy logic toolbox of MATLAB 6.1 MATERIALS AND METHODS

HARDWARE The electronic stethoscope was developed under the guidance of an electronic expert. On a scale of three (1. Good 2. Better 3. Best) the doctors were asked to evaluate the overall performance of both the conventional and electronic stethoscope as per the questionnaire given to them.

STRUCTURE OF FUZZY EXPERT SYSTEM SOUND ANALYSIS (MAMDANI) CONDITION INPUT 1 INPUT 2 INPUT 3 INPUT 4

HEART SOUNDS ANALYSIS INPUT VARIABLES  Heart sound absence or presence (HSA, HSP)  Intensity (NOR, DEC, INC)  Number of heart sounds heard (L2S, M2S)  Presence or absence of added sounds (ASP,ASA)  Character of the heard sound (NOR, ABN) OUTPUT VARIABLE Patient condition (CDN)

DISEASES  PERICARDIAL EFFUSION  LEFT VENTRICULAR FAILURE  AORTIC STENOSIS  MITRAL STENOSIS SAMPLE RULE If (HSP/A is HSP) and (INT is INC) and (CHAR is ABN) then (CDN is MS)

CDN = AORTIC STENOSIS

LUNGS SOUNDS ANALYSIS INPUT VARIABLES  Breath sound absence or presence (BSA, BSP)  Normal vesicular or Bronchial (NORV, NORB)  Presence or absence of added sounds (ASP,ASA)  If added sounds present (rals or rhonchi) (ASRA, ASRO)  Nature of the heard sound ( tubular or cavernous ) (T, C) OUTPUT VARIABLE Patient condition (CDN)

DISEASES  Lung Consolidation  Lung cavity  Lung Parenchymal Disease  Lung Bronchial Disease SAMPLE RULE If (BSP/A is BSP) and (ASA/P is ASP) and (ASRA/RO is ASRO) then (CDN is LBD)

CDN =Lung bronchial disease

INTESTINAL SOUNDS ANALYSIS INPUT VARIABLES  Intestine sound absence or presence (ISA, ISP)  Intensity (NOR, DEC, INC)  Duration (SD, LD)  Site of the heard sound (UA, LA) OUTPUT VARIABLE Patient condition (CDN)

DISEASES  PERITONITIS  PERFORATION  LARGE INTESTINAL OBSTRUCTION  SMALL INTESTINAL OBSTRUCTION SAMPLE RULE If (ISA/P is ISP) and (INT is INC) and (DUR is LD) and (SITE is UA) then (CDN is SIO)

CDN = Small intestinal obstruction

PREAMPLIFIER Amplify low level signals BUFFER AMPLIFIER Second stage of amplification FILTER CIRCUIT To suppress whistling sound due to high feedback MAIN AMPLIFIER TBA 810 versatile audio amplifier

1Intensity12 2Number12 3Opening snap12 4Murmur12 5Click12

1Vesicular12 2Bronchial breath sound12 3Added sounds12 1Intensity12 2Character12

The paper describes a design of a fuzzy expert system for determination of the possibility of the diagnosis of the abnormal body sounds, which can be used by the doctors with hearing impairment and by the students for learning the sounds. Developed FES for various body sounds were compared with the clinical data given by the doctor under different clinical settings

The electronic stethoscopes scored over conventional stethoscopes by its better audibility, quality etc. A good CS cost about Rs 125/- whereas a good ES will cost any where between 7000 to 8000 (About seventy times) whereas ours /- One distinct advantage of ES is its extent of audibility of sounds for in a CS only the examining doctor can hear the sound.