Prediction of Total Pressure Drop in Stenotic Coronary Arteries with Their Geometric Parameters
|
|
- Janis King
- 5 years ago
- Views:
Transcription
1 Tenth Internatonal Conference on Computatonal Flud Dynamcs (ICCFD10), Barcelona, Span, July 9-13, 2018 ICCFD Predcton of Total Pressure Drop n Stenotc Coronary Arteres wth Ther Geometrc Parameters Jaerm Km *, Dohyun Jn *, Haecheon Cho *, Jhoon Kweon **, Young-Hak Km **, Dong Hyun Yang ** and Namkug Km ** Correspondng author: cho@snu.ac.kr * Department of Mechancal and Aerospace Engneerng, Seoul Natonal Unversty, Seoul, Korea. ** Department of Cardology, Unversty of Ulsan College of Medcne, Asan Medcal Center, Seoul, Korea. Abstract: It s essental to accurately assess the severty of a coronary artery stenoss. However, assessments based on the extent of dameter or area reducton (DS or AS) s known to over- or underestmate the functonal severty of stenoss, pressure drop. Therefore, we nvestgate the effects of other geometrc characterstcs as well as AS on the total pressure drop. The numercal smulatons of 31 patent-specfc coronary arteres and 4 dealzed stenoss models are conducted. In the convergng part of the stenoss, the skewed velocty profles toward the outer wall and secondary flow structures n a curved secton are observed. Based on them, the total pressure drop n the convergng part s estmated from the classcal vscous theory assumng the vessel as a seres of curved ppes. The total pressure drop n the dvergng part s estmated by machne learnng technque usng geometrc parameters suggested n ths study. The predcton of total pressure drop s more accurate when we consder the curvature, length, and posteror structure of a stenoss n addton to the mnmum dameter or area. Keywords: Total Pressure Drop, Coronary Artery Stenoss, Curvature, Vscous Theory, Machne Learnng. 1 Introducton Coronary arteres play an mportant role n supplyng blood to the heart, so that stenoss wthn them may cause serous heart falures, and even death. Therefore, t s mportant to determne the severty of coronary artery stenoss. There are two methods to dagnose the rsk of coronary artery stenoss; an assessment of the degree of reducton n dameter (DS) or area (AS) of a stenoss from coronary angography, and an assessment of the pressure drop across a stenoss by nsertng a pressure wre nto the stenosed vessel. In clncal practce, t has been commonly used to measure DS or AS from angography, nstead of pressure drop, due to the lower prce or relatvely convenent procedure. However, some studes have shown that these geometrc-based dagnostcs are not hghly correlated wth the pressure drop whch represents the actual severty of a stenoss [1]. Therefore, a number of studes have been performed to nvestgate the effects of other geometrc factors on the pressure drop caused by stenoss [2, 3, 4]. Also, several studes have been carred out to predct the pressure drop based on the geometrc characterstcs of a stenoss [5, 6, 7]. Although Young & Tsa [5] proposed an equaton for the pressure drop approxmaton for the dealzed axsymmetrc and nonsymmetrc stenoss models, the emprcal coeffcents should be determned a posteror by regresson for each model. 1
2 Schrauwen et al. [6, 7] estmated the pressure drop n stenotc coronary arteres based on ther patentspecfc geometres. In [6], each artery was deconstructed nto four models, addng complexty; straght, tapered, stenosed, and curved models. From the smulaton results, they found the relatons between addtonal pressure drops and geometres, but the smulatons were conducted n lmted geometres such as mldly dseased arteres. In [7], they estmated the pressure drop n straghtened stenotc coronary arteres by substtutng the predcted velocty profle wth geometrc parameters nto smplfed Naver-Stokes equatons. However, t cannot be appled to real vessels havng curvatures. Therefore, n the present study, we use 31 patent-specfc coronary artery models reconstructed from CT mages and 4 dealzed stenoss models of [8]. Drect numercal smulatons are performed to dentfy the geometrc parameters that affect the pressure drop. On the bass of them, we propose a method to predct total pressure drop usng flud mechancs and machne learnng for varous shapes of patent-specfc coronary artery stenoses. 2 Numercal detals Fgure 1 shows the schematc dagram of the computatonal doman. Smulatons are conducted at the Reynolds numbers of 100, 200, and 300 based on the area and flow rate of the reference vessel (see Fgure 1). The governng equatons for blood flow are the contnuty and ncompressble Naver-Stokes equatons: u x 0, (1) 2 u uu j p u t x x x x j j j j. ( 2 ) An unstructured fnte volume method s used to solve the governng equatons [9]. We apply the second-order tme-accurate fractonal step method [10] and symmetrc nterpolaton for arbtrarly nonunform meshes [11] for the tme advancement and spatal dscretzaton, respectvely. A constant flow rate wth unform velocty profle s used at the nlet, and a resstance boundary condton [12] s appled for each coronary outlet. Fgure 1: Computatonal doman of a coronary artery model. The pont O ndcates the poston where the cross-sectonal area of a stenoss becomes the mnmum. 2
3 3 Result and dscusson 3.1 Total pressure drops n stenotc coronary arteres Fgure 2 (a) shows the nondmensonal total pressure drop versus the AS for 31 patent-specfc and 4 dealzed stenoss models at Re = 200. It s notceable that, even wth a smlar AS, dfferent models have smlar (e.g., P13 and P29) or sgnfcantly dfferent (e.g., P13 and P5) nondmensonal total pressure drops. Also, some models such as P13 and P29 have total pressure drops smlar to those of models havng much larger AS. Fgures 2 (b) and (c) show the nondmensonal total pressure drops n the convergng and dvergng parts, respectvely. The nondmensonal total pressure drops n the convergng part are smaller than those n the dvergng part for most models (see the y-axs scale dfferences n these fgures). The nondmensonal total pressure drop n the convergng part has less relevance to the AS, whle that n the dvergng part shows a rather strong relatonshp wth the AS. However, even wth smlar AS s, consderable dfferences n the total pressure drop are observed among varous models (Fgure 2 (c)). Therefore, there s an addtonal total pressure drop due to structural dfferences among models n the dvergng part. Fgure 2: Nondmensonal total pressure drops n the (a) whole, (b) convergng, and (c) dvergng parts of the stenoss. 3.2 Predcton of the total pressure drop n the convergng part of stenoss The P29 has a hgh nondmensonal total pressure drop n the convergng part of a stenoss among models havng smlar AS. The contours of normalzed streamwse velocty and total pressure varaton along the centerlne of the vessel are shown n Fgure 3. In the convergng part, we observe apparent curvatures of vessel centerlne and skewed velocty dstrbuton toward the outer wall. We predct the total pressure drop n the convergng part wth the classcal vscous theory by assumng the blood vessel as a seres of curved ppes [13]. We also consder the vessel as a seres of straght ppes and apply the vscous theory to predct the total pressure dstrbuton. As shown n Fgure 3 (b), the total pressure along the centerlne of the vessel s well predcted by the vscous theory wth curved ppe assumpton, whereas t s not accurately predcted wth straght ppe approaxmaton. Ths ndcates that not only AS but also length and curvature of a stenoss have sgnfcant effects on total pressure drop. On the other hand, ths smple vscous theory cannot predct the total pressure varaton n the dvergng part due to large reverse flow regon there (Fgure 3 (a)). Therefore, a separate approach s requred to predct the total pressure n the dvergng part of a stenoss. 3
4 Fgure 3: Flow characterstcs n the convergng part of P29: (a) contours of the streamwse velocty; (b) varaton of total pressure along the centerlne of the vessel and those predcted wth assumptons of straght and curved ppes. 3.3 Predcton of total pressure drops n the dvergng part of the stenoss Fgure 4 (a) shows the contours of the normalzed streamwse velocty n the dvergng parts of P3 and P10. P3 and P10 have smlar AS s but very dfferent nondmensonal total pressure drops. In the case of P3 where the total pressure loss s rather large, the flow drecton s greatly changed n the dvergng part, whereas P10 has a rather straght dvergng part. Thus, we suggest geometrc parameters, and (Fgure 4 (b)), and the total pressure drop n the dvergng part s estmated usng kernel rdge l regresson (KRR), one of the well-known machne learnng technques, wth these geometrc parameters. To consder the total pressure drop dependng on the flow rate, we consder Re = 100, 200, and 300 for each coronary artery model. The nput features nclude mnmum dameter (d mn/d ref), sn, /d ref and Re. The data set s randomly splt nto tranng and test set as 7:3 rato, and the test set s l used to valdate the machne learnng model. Fgure 5 shows the comparson of the total pressure drops n the dvergng part from CFD and machne learnng. Although the pressure drop n the dvergng part s domnantly determned by d mn/d ref (R 2 = 0.82), hgher coeffcents of determnaton are obtaned when ncludng other parameters: e.g., R 2 = 0.92, 0.84, 0.85 n Fgures 5 (b), (c) and (d), respectvely. Fgure 4: Flow characterstcs n the dvergng part of P3 and P10, and defntons of geometrc parameters: (a) contours of the streamwse velocty; (b) and l. 4
5 Fgure 5: Comparsons of the total pressure drop n the dvergng part of stenoss from CFD and machne learnng: wth varous nput feature combnatons: (a) d mn/d ref and Re; (b) d mn/d ref, /d ref and Re; (c) d mn/d ref, sn and Re; (d) d mn/d ref, denote the cases of Re = 100, 200 and 300, respectvely. 3.4 Predcton of total pressure drops n the stenotc coronary arteres Fgures 6 shows the comparson of the total pressure drops between the CFD results and present predctons n the convergng, dvergng, and whole parts, respectvely. In Fgure 6, the results from CFD and predcton are well correlated when consderng curvature, /d ref and d mn/d ref (R 2 = 0.95) than only consderng d mn /d ref (R 2 = 0.82). l /d ref, sn and Re. Here, red, green and blue symbols l l Fgure 6: Comparsons of the total pressure drop from CFD and present predcton. Here, the red symbols are the predcton consderng /d ref and d mn/d ref, and green symbols are the predcton l consderng only d mn/d ref. sold and open symbols represent the tranng and test sets. 5
6 4 Conclusons We ntroduced a classcal vscous theory assumng the convergng part of a stenoss as a curvedconnected ppe and machne learnng method n the dvergng part of the stenoss, to predct the total pressure drop. 31 patent-specfc and 4 dealzed models were used n ths study. The total pressure drop across the stenoss was well predcted by the present approach. In the present study, we consder steady nflow only. In the future, pulsatle nflow condtons wll be consdered. Acknowledgments Ths work s supported by the research grants (Nos. NRF-2016R1E1A1A and NRF- 2014M3C1B ). References [1] S.-J. Park, S.-J. Kang, J.-M. Ahn, E.B. Shm, Y.-T. Km, S.-C. Yun, H. Song, J.-Y. Lee, W.-J. Km, D.-W. Park, S. Lee, Y. Km, C. Lee, G. S. Mntz and S. Park. Vsual-functonal msmatch between coronary angography and fractonal flow reserve. JACC. Cardovasc. Interv., 5: , [2] S. Kamangar, G. Kalmuthu, I. Anjum Badruddn, A. Badarudn, N. Salman Ahmed and T. Khan. Numercal nvestgaton of the effect of stenoss geometry on the coronary dagnostc parameters. Sc. World. J., 2014: , [3] K. Govndaraju, G.N. Vswanathan, I.A. Badruddn, S. Kamangar, N. Salman Ahmed and A.A. Al-Rashed. The nfluence of artery wall curvature on the anatomcal assessment of stenoss severty derved from fractonal flow reserve: a computatonal flud dynamcs study. Comput. Methods. Bomech. Bomed. Eng., 19: , [4] C. Peng, X. Wang, Z. Xan, X. Lu, W. Huang, P. Xu and J. Wang. The mpact of the geometrc characterstcs on the hemodynamcs n the stenotc coronary artery. PloS one. 11:e , [5] D.F. Young and F.Y. Tsa. Flow characterstcs n models of arteral stenoses I. Steady flow. J. Bomech. 6: , [6] J. Schrauwen, J. Wentzel, A. van der Steen and F. Gjsen. Geometry-based pressure drop predcton n mldly dseased human coronary arteres. J. Bomech., 47: , [7] J.T. Schrauwen, D.J. Koeze, J.J. Wentzel, F.N. van de Vosse, A.F. van der Steen and F.J. Gjsen. Fast and accurate pressure-drop predcton n straghtened atherosclerotc coronary arteres. Ann. Bomed. Eng., 43:59-67, [8] S.S. Varghese, S.H. Frankel and P.F. Fscher. Drect numercal smulaton of stenotc flows. Part 1. Steady flow. Journal of Flud Mechancs. 582: , [9] D. Km and H. Cho. A second-order tme-accurate fnte volume method for unsteady ncompressble flow on hybrd unstructured grds. J. Comput. Phys., 162: , [10] H. Cho and P. Mon. Effects of the computatonal tme step on numercal solutons of turbulent flow. J. Comput. Phys., 113:1-4, [11] K. Mahesh, G. Constantnescu and P. Mon. A numercal method for large-eddy smulaton n complex geometres. J. Comput. Phys., 197: , [12] I.E. Vgnon-Clementel, C.A. Fgueroa, K.E. Jansen and C.A. Taylor. Outflow boundary condtons for three-dmensonal fnte element modelng of blood flow and pressure n arteres. Computer methods n appled mechancs and engneerng. 195: , [13] C. Whte. Streamlne flow through curved ppes. Proc. R. Soc. Lond. A., 123: ,
HEMODYNAMIC SIMULATION FOR CONGENITAL HEART DISEASE
Seventh Internatonal Conference on CFD n the Mnerals and Process Industres CSIRO, Melbourne, Australa 9-11 December 2009 HEMODYNAMIC SIMULATION FOR CONGENITAL HEART DISEASE J L LIU 1, Y QIAN 1, 4*, M UMEZU
More informationUsing the Perpendicular Distance to the Nearest Fracture as a Proxy for Conventional Fracture Spacing Measures
Usng the Perpendcular Dstance to the Nearest Fracture as a Proxy for Conventonal Fracture Spacng Measures Erc B. Nven and Clayton V. Deutsch Dscrete fracture network smulaton ams to reproduce dstrbutons
More informationModeling the Survival of Retrospective Clinical Data from Prostate Cancer Patients in Komfo Anokye Teaching Hospital, Ghana
Internatonal Journal of Appled Scence and Technology Vol. 5, No. 6; December 2015 Modelng the Survval of Retrospectve Clncal Data from Prostate Cancer Patents n Komfo Anokye Teachng Hosptal, Ghana Asedu-Addo,
More informationTitle. Author(s)Salmingo, Remel; Tadano, Shigeru; Fujisaki, Kazuhiro. CitationClinical Biomechanics, 27(6): Issue Date Doc URL.
Ttle Correctve force analyss for scoloss from mplant Author(s)Salmngo, Remel; Tadano, Shgeru; Fujsak, Kazuhro CtatonClncal Bomechancs, 27(6): 545-550 Issue Date 2012-07 Doc URL http://hdl.handle.net/2115/49633
More informationStudy and Comparison of Various Techniques of Image Edge Detection
Gureet Sngh et al Int. Journal of Engneerng Research Applcatons RESEARCH ARTICLE OPEN ACCESS Study Comparson of Varous Technques of Image Edge Detecton Gureet Sngh*, Er. Harnder sngh** *(Department of
More informationInternational Journal of Emerging Technologies in Computational and Applied Sciences (IJETCAS)
Internatonal Assocaton of Scentfc Innovaton and Research (IASIR (An Assocaton Unfyng the Scences, Engneerng, and Appled Research Internatonal Journal of Emergng Technologes n Computatonal and Appled Scences
More informationEVALUATION OF BULK MODULUS AND RING DIAMETER OF SOME TELLURITE GLASS SYSTEMS
Chalcogende Letters Vol. 12, No. 2, February 2015, p. 67-74 EVALUATION OF BULK MODULUS AND RING DIAMETER OF SOME TELLURITE GLASS SYSTEMS R. EL-MALLAWANY a*, M.S. GAAFAR b, N. VEERAIAH c a Physcs Dept.,
More informationModelling and simulation of fluid-structure interactions in human snoring
19th Internatonal Congress on Modellng and Smulaton, Perth, Australa, 12 16 December 211 http://mssanz.org.au/modsm211 Modellng and smulaton of flud-structure nteractons n human snorng N.S.J. Ellott a,
More informationJoint Modelling Approaches in diabetes research. Francisco Gude Clinical Epidemiology Unit, Hospital Clínico Universitario de Santiago
Jont Modellng Approaches n dabetes research Clncal Epdemology Unt, Hosptal Clínco Unverstaro de Santago Outlne 1 Dabetes 2 Our research 3 Some applcatons Dabetes melltus Is a serous lfe-long health condton
More informationOptimal Planning of Charging Station for Phased Electric Vehicle *
Energy and Power Engneerng, 2013, 5, 1393-1397 do:10.4236/epe.2013.54b264 Publshed Onlne July 2013 (http://www.scrp.org/ournal/epe) Optmal Plannng of Chargng Staton for Phased Electrc Vehcle * Yang Gao,
More informationModeling Multi Layer Feed-forward Neural. Network Model on the Influence of Hypertension. and Diabetes Mellitus on Family History of
Appled Mathematcal Scences, Vol. 7, 2013, no. 41, 2047-2053 HIKARI Ltd, www.m-hkar.com Modelng Mult Layer Feed-forward Neural Network Model on the Influence of Hypertenson and Dabetes Melltus on Famly
More informationEFFICIENCY CONSIDERATIONS FOR THE PURELY TAPERED INTERFERENCE FIT (TIF) ABUTMENTS USED IN DENTAL IMPLANTS
EFFICIENCY CONSIDERATIONS FOR THE PURELY TAPERED INTERFERENCE FIT (TIF) ABUTMENTS USED IN DENTAL IMPLANTS by Dnçer Bozkaya, Graduate Student Snan Müftü 1, Ph.D. Assocate Professor Northeastern Unversty
More informationPrice linkages in value chains: methodology
Prce lnkages n value chans: methodology Prof. Trond Bjorndal, CEMARE. Unversty of Portsmouth, UK. and Prof. José Fernández-Polanco Unversty of Cantabra, Span. FAO INFOSAMAK Tangers, Morocco 14 March 2012
More informationThe Influence of the Isomerization Reactions on the Soybean Oil Hydrogenation Process
Unversty of Belgrade From the SelectedWorks of Zeljko D Cupc 2000 The Influence of the Isomerzaton Reactons on the Soybean Ol Hydrogenaton Process Zeljko D Cupc, Insttute of Chemstry, Technology and Metallurgy
More informationEfficiency Considerations for the Purely Tapered Interference Fit (TIF) Abutments Used in Dental Implants
Dnçer Bozkaya Graduate Student Snan Müftü* Ph.D., Assocate Professor Northeastern Unversty, Department of Mechancal Engneerng, Boston, MA 0115 Effcency Consderatons for the Purely Tapered Interference
More information310 Int'l Conf. Par. and Dist. Proc. Tech. and Appl. PDPTA'16
310 Int'l Conf. Par. and Dst. Proc. Tech. and Appl. PDPTA'16 Akra Sasatan and Hrosh Ish Graduate School of Informaton and Telecommuncaton Engneerng, Toka Unversty, Mnato, Tokyo, Japan Abstract The end-to-end
More informationInvestigation of zinc oxide thin film by spectroscopic ellipsometry
VNU Journal of Scence, Mathematcs - Physcs 24 (2008) 16-23 Investgaton of znc oxde thn flm by spectroscopc ellpsometry Nguyen Nang Dnh 1, Tran Quang Trung 2, Le Khac Bnh 2, Nguyen Dang Khoa 2, Vo Th Ma
More informationParameter Estimates of a Random Regression Test Day Model for First Three Lactation Somatic Cell Scores
Parameter Estmates of a Random Regresson Test Day Model for Frst Three actaton Somatc Cell Scores Z. u, F. Renhardt and R. Reents Unted Datasystems for Anmal Producton (VIT), Hedeweg 1, D-27280 Verden,
More informationA Linear Regression Model to Detect User Emotion for Touch Input Interactive Systems
2015 Internatonal Conference on Affectve Computng and Intellgent Interacton (ACII) A Lnear Regresson Model to Detect User Emoton for Touch Input Interactve Systems Samt Bhattacharya Dept of Computer Scence
More informationA MIXTURE OF EXPERTS FOR CATARACT DIAGNOSIS IN HOSPITAL SCREENING DATA
Journal of Theoretcal and Appled Informaton Technology 2005 ongong JATIT & LLS ISSN: 1992-8645 www.jatt.org E-ISSN: 1817-3195 A MIXTURE OF EXPERTS FOR CATARACT DIAGNOSIS IN HOSPITAL SCREENING DATA 1 SUNGMIN
More informationImportance of Atrial Compliance in Cardiac Performance
Importance of Atral Complance n Cardac Performance By Hroyuk Suga ABSTRACT Effects of changes n atral complance on cardac performance were analyzed usng a crculatory analog model. The atrum was assumed
More informationA-UNIFAC Modeling of Binary and Multicomponent Phase Equilibria of Fatty Esters+Water+Methanol+Glycerol
-UNIFC Modelng of Bnary and Multcomponent Phase Equlbra of Fatty Esters+Water+Methanol+Glycerol N. Garrdo a, O. Ferrera b, R. Lugo c, J.-C. de Hemptnne c, M. E. Macedo a, S.B. Bottn d,* a Department of
More informationA Novel artifact for evaluating accuracies of gear profile and pitch measurements of gear measuring instruments
A Novel artfact for evaluatng accuraces of gear profle and ptch measurements of gear measurng nstruments Sonko Osawa, Osamu Sato, Yohan Kondo, Toshyuk Takatsuj (NMIJ/AIST) Masaharu Komor (Kyoto Unversty)
More informationStatistical Analysis on Infectious Diseases in Dubai, UAE
Internatonal Journal of Preventve Medcne Research Vol. 1, No. 4, 015, pp. 60-66 http://www.ascence.org/journal/jpmr Statstcal Analyss on Infectous Dseases 1995-013 n Duba, UAE Khams F. G. 1, Hussan H.
More informationUnobserved Heterogeneity and the Statistical Analysis of Highway Accident Data
Unobserved Heterogenety and the Statstcal Analyss of Hghway Accdent Data Fred L. Mannerng Professor of Cvl and Envronmental Engneerng Courtesy Department of Economcs Unversty of South Florda 4202 E. Fowler
More informationEvaluation of the generalized gamma as a tool for treatment planning optimization
Internatonal Journal of Cancer Therapy and Oncology www.jcto.org Evaluaton of the generalzed gamma as a tool for treatment plannng optmzaton Emmanoul I Petrou 1,, Ganesh Narayanasamy 3, Eleftheros Lavdas
More informationLength of Hospital Stay After Acute Myocardial Infarction in the Myocardial Infarction Triage and Intervention (MITI) Project Registry
JACC Vol. 28, No. 2 287 CLINICAL STUDIES MYOCARDIAL INFARCTION Length of Hosptal Stay After Acute Myocardal Infarcton n the Myocardal Infarcton Trage and Interventon (MITI) Project Regstry NATHAN R. EVERY,
More informationA POROUS MEDIA APPROACH TOWARDS A DYNAMIC MECHANISTIC MODEL OF DRUG ELIMINATION BY THE LIVER. A Thesis Submitted to the
A POROUS MEDIA APPROAH TOWARDS A DYNAMI MEHANISTI MODEL OF DRUG ELIMINATION BY THE LIVER A Thess Submtted to the ollege of Graduate Studes and Research n Partal Fulfllment of the Requrements for the Degree
More informationShape-based Retrieval of Heart Sounds for Disease Similarity Detection Tanveer Syeda-Mahmood, Fei Wang
Shape-based Retreval of Heart Sounds for Dsease Smlarty Detecton Tanveer Syeda-Mahmood, Fe Wang 1 IBM Almaden Research Center, 650 Harry Road, San Jose, CA 95120. {stf,wangfe}@almaden.bm.com Abstract.
More informationPhysical Model for the Evolution of the Genetic Code
Physcal Model for the Evoluton of the Genetc Code Tatsuro Yamashta Osamu Narkyo Department of Physcs, Kyushu Unversty, Fukuoka 8-856, Japan Abstract We propose a physcal model to descrbe the mechansms
More informationThe Study of Gearing Line Limits of the Cycloid Gear With Roller Teeth
ISSN 1224-3264, Volume 2013 No.XXVII The Study o Gearng Lne Lmts o the Cyclod Gear Wth Roller Teeth Dăscălescu, Anamara Abstract: From dynamc pont o vew, at the cyclod gear transmsson s not ratonal to
More information(From the Gastroenterology Division, Cornell University Medical College, New York 10021)
ROLE OF HEPATIC ANION-BINDING PROTEIN IN BROMSULPHTHALEIN CONJUGATION* BY N. KAPLOWITZ, I. W. PERC -ROBB,~ ANn N. B. JAVITT (From the Gastroenterology Dvson, Cornell Unversty Medcal College, New York 10021)
More informationRENAL FUNCTION AND ACE INHIBITORS IN RENAL ARTERY STENOSISA/adbon et al. 651
Downloaded from http://ahajournals.org by on January, 209 RENAL FUNCTION AND INHIBITORS IN RENAL ARTERY STENOSISA/adbon et al. 65 Downloaded from http://ahajournals.org by on January, 209 Patents and Methods
More informationResearch Article Statistical Analysis of Haralick Texture Features to Discriminate Lung Abnormalities
Hndaw Publshng Corporaton Internatonal Journal of Bomedcal Imagng Volume 2015, Artcle ID 267807, 7 pages http://dx.do.org/10.1155/2015/267807 Research Artcle Statstcal Analyss of Haralck Texture Features
More informationEstimation for Pavement Performance Curve based on Kyoto Model : A Case Study for Highway in the State of Sao Paulo
Estmaton for Pavement Performance Curve based on Kyoto Model : A Case Study for Kazuya AOKI, PASCO CORPORATION, Yokohama, JAPAN, Emal : kakzo603@pasco.co.jp Octávo de Souza Campos, Publc Servces Regulatory
More informationWHO S ASSESSMENT OF HEALTH CARE INDUSTRY PERFORMANCE: RATING THE RANKINGS
WHO S ASSESSMENT OF HEALTH CARE INDUSTRY PERFORMANCE: RATING THE RANKINGS ELLIOTT PARKER and JEANNE WENDEL * Department of Economcs, Unversty of Nevada, Reno, NV, USA SUMMARY Ths paper examnes the econometrc
More informationFast Algorithm for Vectorcardiogram and Interbeat Intervals Analysis: Application for Premature Ventricular Contractions Classification
Fast Algorthm for Vectorcardogram and Interbeat Intervals Analyss: Applcaton for Premature Ventrcular Contractons Classfcaton Irena Jekova, Vessela Krasteva Centre of Bomedcal Engneerng Prof. Ivan Daskalov
More informationStatistical models for predicting number of involved nodes in breast cancer patients
Vol.2, No.7, 641-651 (2010) do:10.4236/health.2010.27098 Health Statstcal models for predctng number of nvolved nodes n breast cancer patents Alok Kumar Dwved 1 *, Sada Nand Dwved 2, Suryanarayana Deo
More informationINITIAL ANALYSIS OF AWS-OBSERVED TEMPERATURE
INITIAL ANALYSIS OF AWS-OBSERVED TEMPERATURE Wang Yng, Lu Xaonng, Ren Zhhua, Natonal Meteorologcal Informaton Center, Bejng, Chna Tel.:+86 684755, E-mal:cdcsjk@cma.gov.cn Abstract From, n Chna meteorologcal
More informationALMALAUREA WORKING PAPERS no. 9
Snce 1994 Inter-Unversty Consortum Connectng Unverstes, the Labour Market and Professonals AlmaLaurea Workng Papers ISSN 2239-9453 ALMALAUREA WORKING PAPERS no. 9 September 211 Propensty Score Methods
More informationProject title: Mathematical Models of Fish Populations in Marine Reserves
Applcaton for Fundng (Malaspna Research Fund) Date: November 0, 2005 Project ttle: Mathematcal Models of Fsh Populatons n Marne Reserves Dr. Lev V. Idels Unversty College Professor Mathematcs Department
More informationDetection of Lung Cancer at Early Stage using Neural Network Techniques for Preventing Health Care
IJSRD - Internatonal Journal for Scentfc Research & Development Vol. 3, Issue 4, 15 ISSN (onlne): 31-613 Detecton of Lung Cancer at Early Stage usng Neural Network echnques for Preventng Health Care Megha
More informationCONSTRUCTION OF STOCHASTIC MODEL FOR TIME TO DENGUE VIRUS TRANSMISSION WITH EXPONENTIAL DISTRIBUTION
Internatonal Journal of Pure and Appled Mathematcal Scences. ISSN 97-988 Volume, Number (7), pp. 3- Research Inda Publcatons http://www.rpublcaton.com ONSTRUTION OF STOHASTI MODEL FOR TIME TO DENGUE VIRUS
More informationSparse Representation of HCP Grayordinate Data Reveals. Novel Functional Architecture of Cerebral Cortex
1 Sparse Representaton of HCP Grayordnate Data Reveals Novel Functonal Archtecture of Cerebral Cortex X Jang 1, Xang L 1, Jngle Lv 2,1, Tuo Zhang 2,1, Shu Zhang 1, Le Guo 2, Tanmng Lu 1* 1 Cortcal Archtecture
More informationValidation of a novel noninvasive cardiac index of left ventricular contractility in patients
Am J Physol Heart Crc Physol 292: H2764 H2772, 2007. Frst publshed January 19, 2007; do:10.1152/ajpheart.00540.2006. Valdaton of a novel nonnvasve cardac ndex of left ventrcular contractlty n patents Lang
More informationMyocardial Mural Thickness During the Cardiac Cycle
Myocardal Mural Thckness Durng the Cardac Cycle By Erc O. Fegl, M.D., and Donald L. Fry, M.D. An understandng of the relatonshp between forces and veloctes of contracton n muscle fbers to the pressures
More informationHIV/AIDS-related Expectations and Risky Sexual Behavior in Malawi
Unversty of Pennsylvana ScholarlyCommons PSC Workng Paper Seres 7-29-20 HIV/AIDS-related Expectatons and Rsky Sexual Behavor n Malaw Adelne Delavande RAND Corporaton, Nova School of Busness and Economcs
More information2011 American Control Conference on O'Farrell Street, San Francisco, CA, USA June 29 - July 01, 2011
011 Amercan Control Conference on O'Farrell Street, San Francsco, CA, USA June 9 - July 01, 011 Modelng the Effect of emozolomde reatment on Orthotopc Models of Gloma Francsco G. Vtal-Lopez, Costas D.
More informationThe effect of salvage therapy on survival in a longitudinal study with treatment by indication
Research Artcle Receved 28 October 2009, Accepted 8 June 2010 Publshed onlne 30 August 2010 n Wley Onlne Lbrary (wleyonlnelbrary.com) DOI: 10.1002/sm.4017 The effect of salvage therapy on survval n a longtudnal
More informationOPTIMIZE THE POSITION OF MECHANICAL COMPONENTS OF AN EXTERNAL FIXATOR USING NEURAL NETWORKS AND GENETIC ALGORITHMS
SYMOMP 2013 Lsbon, 9-10 September 2013 EOMAS, Portugal OPTIMIZE THE POSITION OF MEHANIAL OMPONENTS OF AN EXTERNAL FIXATOR USING NEURAL NETWORKS AND GENETI ALGORITHMS Mguel Samarra 1,3, Lus Rosero 2,3 *,
More informationExperimental Study of Dielectric Properties of Human Lung Tissue in Vitro
Journal of Medcal and Bologcal Engneerng, 34(6): 598-64 598 Expermental Study of Delectrc Propertes of Human Lung Tssue n Vtro Je-Ran Wang 1 Ben-Yuan Sun 1 Hua-Xang Wang 1,* Shan Pang 1 Xao Xu Qng Sun
More informationHIV/AIDS-related Expectations and Risky Sexual Behavior in Malawi
HIV/AIDS-related Expectatons and Rsky Sexual Behavor n Malaw Adelne Delavande Unversty of Essex and RAND Corporaton Hans-Peter Kohler Unversty of Pennsylvanna January 202 Abstract We use probablstc expectatons
More informationEstimation of System Models by Swarm Intelligent Method
Sensors & Transducers 04 by IA Publshng, S. L. http://www.sensorsportal.com Estmaton of System Models by Swarm Intellgent Method,* Xaopng XU, Ququ ZHU, Feng WANG, Fuca QIAN, Fang DAI School of Scences,
More informationGene Selection Based on Mutual Information for the Classification of Multi-class Cancer
Gene Selecton Based on Mutual Informaton for the Classfcaton of Mult-class Cancer Sheng-Bo Guo,, Mchael R. Lyu 3, and Tat-Mng Lok 4 Department of Automaton, Unversty of Scence and Technology of Chna, Hefe,
More informationOptimization of Neem Seed Oil Extraction Process Using Response Surface Methodology
ISSN 4-186 (Paper) ISSN 5-091 (Onlne) Vol., No.6, 01 Optmzaton of Neem Seed Ol Extracton Process Usng Response Surface Methodology Tunmse Latfat Adewoye 1 and Oladpupo Olaosebkan Ogunleye 1 Department
More informationEffect of Bone to Implant Contact Percentage on Bone Remodelling Surrounding a Dental Implant
Effect of Bone to Implant Contact Percentage on Bone Remodellng Surroundng a Dental Implant Author Lan, Z., Guan, Hong, Ivanovsk, Saso, Loo, Yew-Chaye, Johnson, Newell, Zhang, H. Publshed 2010 Journal
More informationUsing Past Queries for Resource Selection in Distributed Information Retrieval
Purdue Unversty Purdue e-pubs Department of Computer Scence Techncal Reports Department of Computer Scence 2011 Usng Past Queres for Resource Selecton n Dstrbuted Informaton Retreval Sulleyman Cetntas
More informationST Segment Tracking for Rapid Determination of Patency of the Infarct-Related Artery in Acute Myocardial Infarction
JACC Vol. 26, No. 3 675 ST Segment Trackng for Rapd Determnaton of Patency of the nfarct-related Artery n Acute Myocardal nfarcton ALAND R. FERNANDEZ, MD, RAFAEL F. SEQUERA, MD, FRCP, FACC, SMON CHAKKO,
More informationVolume 30, Issue 1. International Capital Mobility in African Countries: Do the legal origins matter?
Volume 30, Issue 1 Internatonal Captal Moblty n Afrcan Countres: Do the legal orgns matter? Chrysost Bangaké LEO, Unversty of Orléans (France) Jude Eggoh LEO, Unversty of Orléans (France) Abstract Ths
More informationThis article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and
Ths artcle appeared n a journal publshed by Elsever. The attached copy s furnshed to the author for nternal non-commercal research and educaton use, ncludng for nstructon at the authors nsttuton and sharng
More informationAPPLICATION OF GENERALIZED PERTURBATION THEORY TO SENSITIVITY ANALYSIS IN BORON NEUTRON CAPTURE THERAPY
211 Internatonal Nuclear Atlantc Conference - INAC 211 elo Horzonte,MG, razl, October 24-28, 211 AOCIAÇÃO RAILEIRA DE ENERGIA NUCLEAR - AEN IN: 978-85-99141-4-5 APPLICAION OF GENERALIZED PERURAION HEORY
More informationMuscle Activating Force Detection Using Surface Electromyography
Muscle force, F v (v m ) (Fracton of maxmum sometrc force) Muscle force, F l (l m ) (Fracton of maxmum sometrc force) Muscle Actvatng Force Detecton Usng Surface Electromyography Saran KEERATIHATTAYAKORN
More informationNHS Outcomes Framework
NHS Outcomes Framework Doman 1 Preventng people from dyng prematurely Indcator Specfcatons Verson: 1.21 Date: May 2018 Author: Clncal Indcators Team NHS Outcomes Framework: Doman 1 Preventng people from
More informationISOBARIC VAPOR-LIQUID EQUILIBRIUM FOR THE BINARY MIXTURE OF ETHANOL (1) + 1-HEXANOL (2) AT 100 kpa
ISOBARIC VAPOR-LIQUID EQUILIBRIUM FOR THE BINARY MIXTURE OF ETHANOL (1) + 1-HEXANOL (2) AT 100 Pa Dhon Hartanto 1), Asall Mustan 2), Bayu Trwbowo 1), Aula Septan Muta 1) 1) Department of Chemcal Engneerng,
More informationARTICLE IN PRESS Neuropsychologia xxx (2010) xxx xxx
Neuropsychologa xxx (200) xxx xxx Contents lsts avalable at ScenceDrect Neuropsychologa journal homepage: www.elsever.com/locate/neuropsychologa Storage and bndng of object features n vsual workng memory
More informationINTEGRATIVE NETWORK ANALYSIS TO IDENTIFY ABERRANT PATHWAY NETWORKS IN OVARIAN CANCER
INTEGRATIVE NETWORK ANALYSIS TO IDENTIFY ABERRANT PATHWAY NETWORKS IN OVARIAN CANCER LI CHEN 1,2, JIANHUA XUAN 1,*, JINGHUA GU 1, YUE WANG 1, ZHEN ZHANG 2, TIAN LI WANG 2, IE MING SHIH 2 1The Bradley Department
More informationThe Effect of Fish Farmers Association on Technical Efficiency: An Application of Propensity Score Matching Analysis
The Effect of Fsh Farmers Assocaton on Techncal Effcency: An Applcaton of Propensty Score Matchng Analyss Onumah E. E, Esslfe F. L, and Asumng-Brempong, S 15 th July, 2016 Background and Motvaton Outlne
More informationA comparison of statistical methods in interrupted time series analysis to estimate an intervention effect
Peer revew stream A comparson of statstcal methods n nterrupted tme seres analyss to estmate an nterventon effect a,b, J.J.J., Walter c, S., Grzebeta a, R. & Olver b, J. a Transport and Road Safety, Unversty
More informationIntroduction ORIGINAL RESEARCH
ORIGINAL RESEARCH Assessng the Statstcal Sgnfcance of the Acheved Classfcaton Error of Classfers Constructed usng Serum Peptde Profles, and a Prescrpton for Random Samplng Repeated Studes for Massve Hgh-Throughput
More informationRelevance of statistical techniques when using administrative health data: gender inequality in mortality from cardio-vascular disease
Relevance of statstcal technques when usng admnstratve health data: gender nequalty n mortalty from cardo-vascular dsease Julan Perelman Céu Mateus June 2010 Escola Naconal de Saúde Públca, Unversdade
More informationOptimum Degree of Bone-Implant Contact in Bone Remodelling Induced by Dental Implant
Optmum Degree of Bone-Implant Contact n Bone Remodellng Induced by Dental Implant Author Lan, Z., Guan, Hong, Loo, Yew-Chaye Publshed 2011 Journal Ttle Proceda Engneerng DOI https://do.org/10.1016/j.proeng.2011.07.374
More informationAnalysis of Correlated Recurrent and Terminal Events Data in SAS Li Lu 1, Chenwei Liu 2
Statstcs & Analyss Analyss of Correlated Recurrent and ermnal Events Data n SAS L Lu 1, Chenwe Lu 2 1 he EMMES Corporaton, Rockvlle, MD 2 Core Genotypng Faclty, Dvson of Cancer Epdemology and Genetcs,
More informationUsing Finite Element Method to Determine Pad Positions in a Boston Brace for Enhancing Corrective Effect on Scoliotic Spine: A Preliminary Analysis
Journal of Medcal and Bologcal Engneerng, 3(1): 9-35 9 Usng Fnte Element Method to Determne Pad Postons n a Boston Brace for Enhancng Correctve Effect on Scolotc Spne: A Prelmnary Analyss Wen-Ka Chou 1
More informationKOUJI KAJINAMI, MD,*t HIROYASU SEKI, MD,t NOBORU TAKEKOSHI, MD,t HIROSHI MABUCHI, MD* Kanazawa, Japan
JACC Vol. 26, No. 5 209 November I, 995:209-2 Nonnvasve Predcton of Coronary Atheroscleross by Quantfcaton of Coronary Artery Calcfcaton Usng Electron Beam Computed Tomography: Comparson Wth Electrocardographc
More informationStatistically Weighted Voting Analysis of Microarrays for Molecular Pattern Selection and Discovery Cancer Genotypes
IJCSNS Internatonal Journal of Computer Scence and Network Securty, VOL.6 No.2, December 26 73 Statstcally Weghted Votng Analyss of Mcroarrays for Molecular Pattern Selecton and Dscovery Cancer Genotypes
More informationTHE NORMAL DISTRIBUTION AND Z-SCORES COMMON CORE ALGEBRA II
Name: Date: THE NORMAL DISTRIBUTION AND Z-SCORES COMMON CORE ALGEBRA II The normal dstrbuton can be used n ncrements other than half-standard devatons. In fact, we can use ether our calculators or tables
More informationFinite element simulation of bone remodelling in human mandible around osseointegrated dental implant
IOP Conference Seres: Materals Scence and Engneerng Fnte element smulaton of bone remodellng n human mandble around osseontegrated dental mplant To cte ths artcle: Z Q Lan et al 2010 IOP Conf. Ser.: Mater.
More informationDisease Mapping for Stomach Cancer in Libya Based on Besag York Mollié (BYM) Model
DI:0.034/APJCP.07.8.6.479 Dsease Mappng for Stomach Cancer n Lbya: Bayesan Study RESEARC ARTICLE Dsease Mappng for Stomach Cancer n Lbya Based on Besag York Mollé (BYM) Model Maryam Ahmed Salem Alhdr *,
More informationAUTOMATED DETECTION OF HARD EXUDATES IN FUNDUS IMAGES USING IMPROVED OTSU THRESHOLDING AND SVM
AUTOMATED DETECTION OF HARD EXUDATES IN FUNDUS IMAGES USING IMPROVED OTSU THRESHOLDING AND SVM Wewe Gao 1 and Jng Zuo 2 1 College of Mechancal Engneerng, Shangha Unversty of Engneerng Scence, Shangha,
More informationDirect 4D Parametric Imaging in Dynamic Myocardial Perfusion PET
Arman Rahmm et al. Drect 4D Parametrc Imagng n Dynamc Myocardal Perfuson PET Drect 4D Parametrc Imagng n Dynamc Myocardal Perfuson PET Arman Rahmm 1,2*, Jng Tang 3, and Hassan Mohy-ud-Dn 1,2 1. Department
More informationMathematical model of fish schooling behaviour in a set-net
ICES Journal of Marne Scence, 61: 114e13 (004) do:10.1016/j.cesjms.004.07.009 Mathematcal model of fsh schoolng behavour n a set-net Tsutomu Takag, Yutaka Mortom, Jyun Iwata, Hrosh Nakamne, and Nobuo Sannomya
More informationNormal variation in the length of the luteal phase of the menstrual cycle: identification of the short luteal phase
Brtsh Journal of Obstetrcs and Gvnaecologjl July 1984, Vol. 9 1, pp. 685-689 Normal varaton n the length of the luteal phase of the menstrual cycle: dentfcaton of the short luteal phase ELIZABETH A. LENTON,
More informationReceived 23 January 2003; accepted 4 July 2003
DES N ON ELSEVER Desalnaton 164 (2004) 3-62 p,, www.elr~lcr:convl~ale]desal Evaluaton of the performance of tght-uf membranes wth respect to NOM removal usng effectve MWCO, molecular weght, and apparent
More informationEffects of Estrogen Contamination on Human Cells: Modeling and Prediction Based on Michaelis-Menten Kinetics 1
J. Water Resource and Protecton, 009,, 6- do:0.6/warp.009.500 Publshed Onlne ovember 009 (http://www.scrp.org/ournal/warp) Effects of Estrogen Contamnaton on Human Cells: Modelng and Predcton Based on
More informationTOPICS IN HEALTH ECONOMETRICS
TOPICS IN HEALTH ECONOMETRICS By VIDHURA SENANI BANDARA WIJAYAWARDHANA TENNEKOON A dssertaton submtted n partal fulfllment of the requrements for the degree of DOCTOR OF PHILOSOPHY WASHINGTON STATE UNIVERSITY
More informationSurvival Rate of Patients of Ovarian Cancer: Rough Set Approach
Internatonal OEN ACCESS Journal Of Modern Engneerng esearch (IJME) Survval ate of atents of Ovaran Cancer: ough Set Approach Kamn Agrawal 1, ragat Jan 1 Department of Appled Mathematcs, IET, Indore, Inda
More informationAppendix for. Institutions and Behavior: Experimental Evidence on the Effects of Democracy
Appendx for Insttutons and Behavor: Expermental Evdence on the Effects of Democrac 1. Instructons 1.1 Orgnal sessons Welcome You are about to partcpate n a stud on decson-makng, and ou wll be pad for our
More informationSTOCHASTIC MODELS OF PITCH JITTER A D AMPLITUDE SHIMMER FOR VOICE MODIFICATIO
STOCHASTIC MODELS OF PITCH JITTER A D AMPLITUDE SHIMMER FOR VOICE MODIFICATIO Dma Runsky,2 and Yzhar Lavner Department of Computer Scence, Tel-Ha Academc College, Israel 2 Israel Development Center, Intel
More informationMaize Varieties Combination Model of Multi-factor. and Implement
Maze Varetes Combnaton Model of Mult-factor and Implement LIN YANG,XIAODONG ZHANG,SHAOMING LI Department of Geographc Informaton Scence Chna Agrcultural Unversty No. 17 Tsnghua East Road, Bejng 100083
More informationA Mathematical Model of the Cerebellar-Olivary System II: Motor Adaptation Through Systematic Disruption of Climbing Fiber Equilibrium
Journal of Computatonal Neuroscence 5, 71 90 (1998) c 1998 Kluwer Academc Publshers. Manufactured n The Netherlands. A Mathematcal Model of the Cerebellar-Olvary System II: Motor Adaptaton Through Systematc
More informationJournal of Engineering Science and Technology Review 11 (2) (2018) Research Article
Jestr Journal of Engneerng Scence and Technology Revew () (08) 5 - Research Artcle Prognoss Evaluaton of Ovaran Granulosa Cell Tumor Based on Co-forest ntellgence Model Xn Lao Xn Zheng Juan Zou Mn Feng
More informationA Geometric Approach To Fully Automatic Chromosome Segmentation
A Geometrc Approach To Fully Automatc Chromosome Segmentaton Shervn Mnaee ECE Department New York Unversty Brooklyn, New York, USA shervn.mnaee@nyu.edu Mehran Fotouh Computer Engneerng Department Sharf
More informationEXAMINATION OF THE DENSITY OF SEMEN AND ANALYSIS OF SPERM CELL MOVEMENT. 1. INTRODUCTION
JOURNAL OF MEDICAL INFORMATICS & TECHNOLOGIES Vol.3/00, ISSN 64-6037 Łukasz WITKOWSKI * mage enhancement, mage analyss, semen, sperm cell, cell moblty EXAMINATION OF THE DENSITY OF SEMEN AND ANALYSIS OF
More informationPSI Tuberculosis Health Impact Estimation Model. Warren Stevens and David Jeffries Research & Metrics, Population Services International
PSI Tuberculoss Health Impact Estmaton Model Warren Stevens and Davd Jeffres Research & Metrcs, Populaton Servces Internatonal June 2009 Ths document may be freely revewed, quoted, reproduced or translated,
More informationSTAGE-STRUCTURED POPULATION DYNAMICS OF AEDES AEGYPTI
Internatonal Conference Mathematcal and Computatonal Bology 211 Internatonal Journal of Modern Physcs: Conference Seres Vol. 9 (212) 364 372 World Scentfc Publshng Company DOI: 1.1142/S21194512543 STAGE-STRUCTURED
More informationInfluence of concentration of sugar on mass transfer of pineapple slices during osmotic dehydration
J. Bangladesh Agrl. Unv. 2(: 22 226, 24 ISSN 8-33 Influence of concentraton of sugar on mass transfer of pneapple slces durng osmotc dehydraton S. A. A. Khanom, M. M. Rahman 2 and M. B. Uddn 3* Vegetable
More informationWe analyze the effect of tumor repopulation on optimal dose delivery in radiation therapy. We are primarily
INFORMS Journal on Computng Vol. 27, No. 4, Fall 215, pp. 788 83 ISSN 191-9856 (prnt) ó ISSN 1526-5528 (onlne) http://dx.do.org/1.1287/joc.215.659 215 INFORMS Optmzaton of Radaton Therapy Fractonaton Schedules
More informationDrug Prescription Behavior and Decision Support Systems
Drug Prescrpton Behavor and Decson Support Systems ABSTRACT Adverse drug events plague the outcomes of health care servces. In ths research, we propose a clncal learnng model that ncorporates the use of
More informationNon-linear Multiple-Cue Judgment Tasks
Non-lnear Multple-Cue Tasks Anna-Carn Olsson (anna-carn.olsson@psy.umu.se) Department of Psychology, Umeå Unversty SE-09 87, Umeå, Sweden Tommy Enqvst (tommy.enqvst@psyk.uu.se) Department of Psychology,
More informationAre Drinkers Prone to Engage in Risky Sexual Behaviors?
Amercan Internatonal Journal of Socal Scence Vol. 2 No. 5; July 2013 Are Drnkers Prone to Engage n Rsky Sexual Behavors? Ana Isabel Gl Lacruz Zaragoza Unversty Department of Busness Organzaton and Management
More information