Presenter: Wei-Liang Hong Advisor: Dr. Chun-Ju Hou

Outline Problems and Rationale Purpose and Specific Aims Background and Literatures Review Materials and Methods Preliminary Results and Discussion Future works References 2

Problems and Rationale Incidence of renal failure and dialysis number of people (millions) Source: USRDS

Problems and Rationale Treatments for renal failure Kidney transplantation Dialysis Peritoneal dialysis: 9.17% Hemodialysis: 90.83% Native arteriovenous (AV) fistula Synthetic AV shunt (Graft) U-type transplanted fistula Linear transplanted fistula 4

Problems and Rationale 5 Native AV fistula AV graft

Problems and Rationale Complications of arteriovenous fistula (AVF) Infection Bleeding Vascular access dysfunction Stenosis Embolism Steal syndrome Venous hypertension …..

Problems and Rationale Assessments for AVF function Palpated with the fingers Strength of pulse, thrill Auscultation Appear high-pitched bruit or sea-gull murmur (200 ~ 800 Hz) when stenosis occurs Angiography Ultrasound CT

Problems and Rationale Problems in AVF care Insufficient auscultation skill Subjective Depend on individual experience Insufficient manpower Lack of objectively computerized sound analysis

Problems and Rationale Littmann 3200 Bluetooth Stethoscope Frequency of 4K Hz Anti-noise high Transmission for Bluetooth USD-$372.99

Purpose and Specific Aims Establishment of an auscultation system for the evaluation of arteriovenous fistula stenosis Hardware and software design Experimental testing

Analog circuits Wavelet transform STFT FFT Hilbert transform 11 Yen-Nien Wang, Chih-Yang Chan, & Shi-Jun Chou, “The Detection of Arteriovenous Fistula Stenosis for Hemodialysis Based on Wavelet Transform”, International Journal of Advanced Computer Science, Vol. 1, Pp , Jul (Impact Factor 0.740) Background & Literatures Review

(a) Stenosis-free representation; (b) Stenosis representation. 12 Background & Literatures Review

13 Stenosis-free Stenosis Background & Literatures Review

14 Stenosis-free Stenosis Background & Literatures Review

Equipment (BIOPAC, Inc.) 0.05~5k(Hz) Matlab Analysis method Empirical Mode Decomposition (EMD) Pablo V´asquez, Marco Mungu´ıa M., Members IEEE,lisabeth Mattsson, and Bengt Mandersson, “Application of the Empirical Mode Decomposition in the study of murmurs from Arteriovenous Fistula Stenosis”, 32nd Annual International Conference of the IEEE EMBSBuenos Aires, Argentina, August 31 - September 4, 2010 Background & Literatures Review

Equipment (BIOPAC, Inc.) MP-150 system Matlab Analysis method Windkessel Model AR modeling STFT Pablo V´asquez, Marco Mungu´ıa M., Members “Frequency tracking of resonant-like sounds from audio recordings of Arterio-Venous Fistula Stenosis”, 2012 IEEE International Conference on Bioinformatics and Biomedicine Workshops (BIBMW) Background & Literatures Review

CHIRPS ENCOUNTERED IN RECORDINGS. SubjectTypeSignalDurationFund. frequency [Hz] AFist. A1A ± 44.4 A2A ± 63.7 A3A ± 46.4 BGraft B1B ± 28.6 B2B ± 44.1 B3B ± 44.4 CFist. C1C ± 66.3 C2C ± 52.7 DFist. D1D ± 66.3 D2D ± D3D ± 69.7 D4D ± 78.4 D5D ± 85.4 Efistula E1E ± 41.9 E2E ± 90.4