Implementation of a patient-specific cardiac model

2020 ◽  
pp. 43-94
Author(s):  
Viorel Mihalef ◽  
Tommaso Mansi ◽  
Saikiran Rapaka ◽  
Tiziano Passerini
Keyword(s):  
Patient Specific ◽  
Cardiac Model

In vivo application and validation of a novel non-invasive method to estimate the end-systolic elastance

2021 ◽  
Author(s):  
Stamatia Pagoulatou ◽  
Karl-Philipp Rommel ◽  
Karl-Patrik Kresoja ◽  
Maximilian von Roeder ◽  
Philipp Lurz ◽  
...  
Keyword(s):  
Heart Failure ◽  
Systolic Function ◽  
Cuff Pressure ◽  
Left Ventricular ◽  
Aortic Flow ◽  
Arterial System ◽  
Patient Specific ◽  
Correct Prediction ◽  
Non Invasive ◽  
Cardiac Model

Accurate assessment of the left ventricular (LV) systolic function is indispensable in the clinic. However, estimation of a precise index of cardiac contractility, i.e., the end-systolic elastance (Ees), is invasive and cannot be established as clinical routine. The aim of this work was to present and validate a methodology that allows for the estimation of Ees from simple and readily available non-invasive measurements. The method is based on a validated model of the cardiovascular system and non-invasive data from arm-cuff pressure and routine echocardiography to render the model patient-specific. Briefly, the algorithm first uses the measured aortic flow as model input and optimizes the properties of the arterial system model in order to achieve correct prediction of the patient's peripheral pressure. In a second step, the personalized arterial system is coupled with the cardiac model (time-varying elastance model) and the LV systolic properties, including Ees, are tuned to predict accurately the aortic flow waveform. The algorithm was validated against invasive measurements of Ees (multiple pressure-volume loop analysis) taken from n=10 heart failure patients with preserved ejection fraction and n=9 patients without heart failure. Invasive measurements of Ees (median 2.4 mmHg/mL, range [1.0, 5.0] mmHg/mL) agreed well with method predictions (nRMSE=9%, ρ=0.89, bias=-0.1 mmHg/mL and limits of agreement [-0.9, 0.6] mmHg/mL). This is a promising first step towards the development of a valuable tool that can be used by clinicians to assess systolic performance of the LV in the critically ill.

Patient-specific 3D-printed Cardiac Model for Percutaneous Left Atrial Appendage Occlusion

2018 ◽  
Vol 71 (9) ◽  
pp. 762-764 ◽  
Author(s):  
Beatriz Vaquerizo ◽  
Carmen Escabias ◽  
Daniela Dubois ◽  
Gorka Gómez ◽  
Manuel Barreiro-Pérez ◽  
...  
Keyword(s):  
Left Atrial ◽  
Left Atrial Appendage ◽  
Atrial Appendage ◽  
Patient Specific ◽  
Left Atrial Appendage Occlusion ◽  
Cardiac Model ◽  
3D Printed

Abstract 12568: Impact of Aortic Stenosis on Myofiber Stress: Translational Application of Left Ventricle-Aortic Coupling Simulations

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Andrew D Wisneski ◽  
Yunjie Wang ◽  
Reza Salari ◽  
Steve Levine ◽  
Jiang Yao ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Aortic Stenosis ◽  
Patient Specific ◽  
Element Analysis ◽  
Orifice Area ◽  
Valve Orifice ◽  
Lv Dysfunction ◽  
Cardiac Model ◽  
Hyperelastic Model ◽  
Valve Orifice Area

Introduction: Grading aortic stenosis (AS) has traditionally relied on measuring hemodynamic parameters of transvalvular pressure gradient, ejection jet velocity, or estimating valve orifice area. Recent research has highlighted limitations of these criteria at effectively grading AS in presence of left ventricle (LV) dysfunction. We hypothesize that simulations coupling the aorta and LV will provide meaningful insight into myocardial biomechanical derangements that accompany AS. Reference data from the normal ventricle should first be obtained. Methods: A multi-domain cardiac model with representative anatomy and material properties was used to create AS simulations. Finite element analysis was performed with ABAQUS FEA®. An anisotropic hyperelastic model was assigned to the aorta and LV passive properties, while time-varying elastance function governed LV active response. Mild and severe AS were created by restricting the aortic valve orifice area. Results: Global LV myofiber end systolic (ES) stress (mean±SD) was 9.31±10.33 kPa at baseline (no AS), 13.13±10.29 kPa for mild AS, and 16.18±10.59 kPa with severe AS. Mean LV myofiber ES strains were -22.4±8.7%, -22.2±8.9%, and -21.9±9.2%, respectively. Mild and severe AS had significant stress elevation compared to baseline (mild AS vs base; p<0.01, severe AS vs base; p<0.001) and when compared to each other (p<0.01). See Figure 1 . Ventricular regions that experienced greatest magnitude ES stress were (severe AS vs baseline) basal inferior (39.87±14.73 vs 30.02±12.08 kPa; p<0.01), mid-anteroseptal (32.29±11.56 vs 24.79±12.00 kPa; p<0.001), and apex (27.99±8.44 vs 23.52±10.19 kPa; p<0.001). Conclusions: Isolated AS in a normal heart was simulated, and significantly elevated LV myofiber stress was quantified. This data serves as a comparison to future studies that will incorporate patient-specific ventricular geometries and material parameters, aiming to correlate LV biomechanics to AS severity.

Three-dimensional patient-specific cardiac model for surgical planning in Nikaidoh procedure

2014 ◽  
Vol 25 (4) ◽  
pp. 698-704 ◽  
Author(s):  
Israel Valverde ◽  
Gorka Gomez ◽  
Antonio Gonzalez ◽  
Cristina Suarez-Mejias ◽  
Alejandro Adsuar ◽  
...  
Keyword(s):  
Ventricular Septal Defect ◽  
Rapid Prototyping ◽  
Surgical Planning ◽  
Septal Defect ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Patient Specific ◽  
Complex Congenital Heart Disease ◽  
Cardiac Model ◽  
Cardiovascular Models

AbstractPurpose: To explore the use of three-dimensional patient-specific cardiovascular models using rapid prototyping techniques (fused deposition modelling) to improve surgical planning in patients with complex congenital heart disease. Description: Rapid prototyping techniques are used to print accurate three-dimensional replicas of patients' cardiovascular anatomy based on magnetic resonance images using computer-aided design systems. Models are printed using a translucent polylactic acid polymer. Evaluation: As a proof of concept, a model of the heart of a 1.5-year-old boy with transposition of the great arteries, ventricular septal defect and pulmonary stenosis was constructed to help planning the surgical correction. The cardiac model allowed the surgeon to evaluate the location and dimensions of the ventricular septal defect as well as its relationship with the aorta and pulmonary artery. Conclusions: Cardiovascular models constructed by rapid prototyping techniques are extremely helpful for planning corrective surgery in patients with complex congenital malformations. Therefore they may potentially reduce operative time and morbi-mortality.

Evaluation of a computerized cardiovascular simulation system using patient-specific data

2013 ◽  
Vol 61 (S 01) ◽  
Author(s):  
M Kaur ◽  
N Sprunk ◽  
U Schreiber ◽  
R Lange ◽  
J Weipert ◽  
...  
Keyword(s):  
Simulation System ◽  
Patient Specific ◽  
Specific Data ◽  
Cardiovascular Simulation

Effect of CT-based attenuation correction on uptake ratios in skeletal SPECT

2007 ◽  
Vol 46 (01) ◽  
pp. 38-42 ◽  
Author(s):  
V. Schulz ◽  
I. Nickel ◽  
A. Nömayr ◽  
A. H. Vija ◽  
C. Hocke ◽  
...  
Keyword(s):  
Vertebral Body ◽  
Facet Joint ◽  
One Dimension ◽  
Patient Specific ◽  
Data Sets ◽  
Facet Joints ◽  
Lumbar Vertebral Body ◽  
Ct System ◽  
Ct Data ◽  
Attenuation Corrected

SummaryThe aim of this study was to determine the clinical relevance of compensating SPECT data for patient specific attenuation by the use of CT data simultaneously acquired with SPECT/CT when analyzing the skeletal uptake of polyphosphonates (DPD). Furthermore, the influence of misregistration between SPECT and CT data on uptake ratios was investigated. Methods: Thirty-six data sets from bone SPECTs performed on a hybrid SPECT/CT system were retrospectively analyzed. Using regions of interest (ROIs), raw counts were determined in the fifth lumbar vertebral body, its facet joints, both anterior iliacal spinae, and of the whole transversal slice. ROI measurements were performed in uncorrected (NAC) and attenuation-corrected (AC) images. Furthermore, the ROI measurements were also performed in AC scans in which SPECT and CT images had been misaligned by 1 cm in one dimension beforehand (ACX, ACY, ACZ). Results: After AC, DPD uptake ratios differed significantly from the NAC values in all regions studied ranging from 32% for the left facet joint to 39% for the vertebral body. AC using misaligned pairs of patient data sets led to a significant change of whole-slice uptake ratios whose differences ranged from 3,5 to 25%. For ACX, the average left-to-right ratio of the facet joints was by 8% and for the superior iliacal spines by 31% lower than the values determined for the matched images (p <0.05). Conclusions: AC significantly affects DPD uptake ratios. Furthermore, misalignment between SPECT and CT may introduce significant errors in quantification, potentially also affecting leftto- right ratios. Therefore, at clinical evaluation of attenuation- corrected scans special attention should be given to possible misalignments between SPECT and CT.

Knowledge-Based Decision Support for Diagnosis and Therapy: On the Multiple Usability of Patient Data

1989 ◽  
Vol 28 (02) ◽  
pp. 69-77 ◽  
Author(s):  
R. Haux
Keyword(s):  
Expert Systems ◽  
Statistical Data ◽  
Patient Data ◽  
Attribute Selection ◽  
Patient Specific ◽  
Statistical Data Analysis ◽  
Inference Mechanism ◽  
Diagnosis And Therapy ◽  
Knowledge Based ◽  
Clinical Registries

Abstract:Expert systems in medicine are frequently restricted to assisting the physician to derive a patient-specific diagnosis and therapy proposal. In many cases, however, there is a clinical need to use these patient data for other purposes as well. The intention of this paper is to show how and to what extent patient data in expert systems can additionally be used to create clinical registries and for statistical data analysis. At first, the pitfalls of goal-oriented mechanisms for the multiple usability of data are shown by means of an example. Then a data acquisition and inference mechanism is proposed, which includes a procedure for controlling selection bias, the so-called knowledge-based attribute selection. The functional view and the architectural view of expert systems suitable for the multiple usability of patient data is outlined in general and then by means of an application example. Finally, the ideas presented are discussed and compared with related approaches.

Tailoring Communications for Primary Care Settings

1998 ◽  
Vol 37 (02) ◽  
pp. 171-178 ◽  
Author(s):  
B. Glassman ◽  
B. K. Rimer
Keyword(s):  
Primary Care ◽  
Health Professionals ◽  
Contact Time ◽  
Behavioral Changes ◽  
Patient Specific ◽  
Specific Information ◽  
Medical Settings ◽  
Primary Care Settings ◽  
Professional Contact ◽  
Tailored Communications

AbstractIn more and more medical settings, physicians have less and less time to be effective communicators. To be effective, they need accurate, current information about their patients. Tailored health communications can facilitate positive patient-provider communications and foster behavioral changes conducive to health. Tailored communications (TCs) are produced for an individual based on information about that person. The focus of this report is on tailored print communications (TPCs). TPCs also enhance the process of evaluation, because they require a database and the collection of patient-specific information. We present a Tailoring Model for Primary Care that describes the steps involved in creating TPCs. We also provide examples from three ongoing studies in which TPCs are being used in order to illustrate the kinds of variables used for tailoring the products that are developed and how evaluation is conducted. TPCs offer opportunities to expand the reach of health professionals and to give personalized, individualized massages in an era of shrinking professional contact time.

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