Medical Device Analysis

Implanted, intracardiac device design

  • Do you need to determine the stresses and forces on your medical device after implant?
  • Do you need to analyze how your device impacts soft tissue in which it is embedded, how the tissue deforms, how much force and stress is imposed by the device on the tissue?

Insilicomed’s consultants perform large deformation stress analysis of fibrous tissue. We account for greater tissue stiffness in the fiber direction of soft tissue like myocardium or skeletal muscle. We can adjust tissue material parameters to simulate different properties in health and disease. And, we can perform parametric studies making device design modifications to optimize tissue-device interaction using inexpensive simulations, so that you can avoid trial-and-error animal experiments and preclinical studies. Contact Insilicomed for more information…

The performance and reliability of devices such as pacing leads, ventricular assist devices, coronary stents, replacement valves, catheters and other medical devices that are implanted in the heart or circulation for either short or long duration is a major concern of medical device designers and manufacturers, clinicians and FDA. We have also been engaged to analyze the mechanics of corneal implants for vision correction and eye implants to treat glaucoma. Insilicomed’s consultants can simulate the performance of new device designs in the environment of the intact cardiovascular system. Our engineers can perform computational tests before you build expensive prototypes and conduct time-consuming and expensive animal and preclinical studies.

Insilicomed’s simulations also help guide animal and preclinical testing to minimize expensive and time-consuming tests. We optimize testing protocols to help you avoid wasting time and money. Experimental and clinical data are used directly during computational model construction to obtain accurate simulation results. Parametric studies are performed to visualize and understand how changes in device parameters affect cardiac function. And Insilicomed’s detailed patient-specific simulations of cardiac disease states such as myocardial infarction and heart failure can be used to analyze how implants perform under wide-ranging conditions observed in heart disease. We have also analyzed the efficacy of corneal and other ocular implants taking advantage of specialized finite element models to obtain results much more quickly and at lower cost than conventional analysis. Insilicomed is at the forefront of precision medicine in cardiology.

Computational analysis of cardiac images

Insilicomed has deep expertise performing single- and bi-plane image processing and analysis with an entire software suite dedicated for this purpose. As new cardiac imaging technologies such as three-dimensional echocardiography, speckle tracking, cardiac MRI and delayed contrast cardiac CT emerge, a major problem facing clinicians and vendors is less the quality and information content of the images, but rather the interpretation of the increasingly large volumes of complex dynamic three-dimensional data. The next generation of imaging systems will include software that aids the clinical interpretation of the images by building in known properties of the tissues and organs being imaged to derive more fundamental and reliable clinical information. Insilicomed’s cardiac computational models are the most realistic simulations of electrical and mechanical heart function making them unique and ideal for these purposes, taking disparate clinical data such as cardiac images and other clinical measures and integrating them in realistic heart simulations.

Drug discovery

Many disease conditions, especially heart disease, involve complex interactions between networks of molecules, cells and organs. Although drugs target a specific molecule, their efficacy is unpredictable and requires extensive animal and clinical testing. By simulating the function of the normal and diseased heart from cell to organ, Insilicomed’s software platform can help pharmaceutical companies screen candidate therapies. For the first time, medical therapy can be tested in terms of its effect on cardiac function using inexpensive simulations.

Cardiac Restraint Device: Failure and Solution

A novel cardiac restraint device patented by Paracor Medical was failing in pre-clinical trials.Prototypes were cracking under loading from the beating heart. Insilicomed analyzed the problem using Continuity Pro, our custom simulation software. We found that the initial designs were much too stiff and recommended a considerably softer nitinol mesh. Using our inexpensive simulations, the treatment was redesigned and successfully implanted without cracking. This analysis avoided trial-and-error construction of additional prototypes and associated time-consuming and expensive animal testing that was likely to fail. After an initial phase of work over a few months in which Insilicomed identified this problem and determined its solution, Paracor utilized our capabilities in several other phases of follow-up work over a period of several years. More information on ventricular assist devices…

Transcutaneous Aortic Valve Replacement: Strains, Stresses and Forces

Sadra Medical, a subsidiary of Boston Scientific, hired Insilicomed to determine the loading that their transcutaneous aortic valve replacement would need to tolerate during the cardiac cycle. In an initial phase of analysis using Continuity Pro, we simulated the maximum forces that a valve leaflet in the device would “see” during loading. These forces were needed for use in a finite element analysis of the nitinol valve frame on which the leaflets were attached. In subsequent simulations Insilicomed analyzed the tissue strains and stresses in simulated bench tests of bovine pericardial tissue as a prelude to bench tests of the tissue in the Sadra’s laboratories. There is no other way to determine the forces the heart applies to the device without enormously expensive experiments in which small load cells are deployed to measure forces. Insilicomed solved this problem at a fraction of the cost.

Apical Torsion to Improve Heart Function 2: Wall Stresses

To quantify regional mechanics of the heart during the apical torsion intervention, bioengineers know that heart wall stresses accompanying the aforementioned strains must be estimated. Insilicomed analyzed these three-dimensional wall stresses. In this 65-degree case, we show substantial maximum wall stresses as illustrated in the video. Note the maximum stresses don’t correspond precisely to the maximum strains shown previously. At the base (top) of the heart and near the twist zone at apex (bottom), some stress concentrations occur. But large parts of the ventricular wall have low stresses (green signifies zero stress or strain).

More information on ventricular assist devices…

More information on whole organ simulation…

3D Bending of a Left Heart Pacing Lead

St. Jude Medical needed to perform realistic bench testing of their left heart pacing leads used for biventricular pacing in cardiac resynchronization therapy (CRT), a treatment for heart failure. They tasked Insilicomed with developing a custom software module within Continuity Pro to meet their needs. The new software enables users to perform post-processing of biplane cineradiographic images acquired in the clinic. Patients with CRT implants are imaged in the biplane imaging suites at St. Luke’s Hospital in Milwaukee, WI. Insilicomed taught SJM bioengineers how to perform the necessary calibration tasks so that 3D information could be estimated from image pairs. SJM uses these capabilities to determine time-varying bending of the pacing leads in patients. The bending estimates are used in SJM’s bench testing to satisfy FDA’s requirements for realistic bench tests. More information on pacemaker studies…

Mechanics of a Corneal Implant for Vision Correction

Insilicomed was engaged by Revision Optics to analyze the mechanics of their novel corenal implant for vision correction. Using our specialized finite elements in curvilinear coordinate systems (spherical polar coordinates), we were able to model the implant efficiently without the need for extensive finite element mesh development. The analysis showed the range of sizes and thicknesses that could be used for the implants to avoid excessive strains and stresses in the implant material. Insilicomed continued with a multi-phase project for the company. Contact Insilicomed for more information on the analysis of ocular implants.