Development of a patient-specific model of the human coronary system for percutaneous transluminal coronary angioplasty balloon catheter training and testing.

Background: To treat stenosed coronary arteries, percutaneous transluminal coronary angioplasty (PTCA) balloon catheters must combine pushability, trackability, crossability, and rewrap behavior. The existing anatomic track model (ASTM F2394) for catheter testing lacks 3D morphology, vessel tortuosity, and compliance, making evaluating performance characteristics difficult. This study aimed to develop a three-dimensional patient-specific phantom (3DPSP) for device testing and safe training for interventional cardiologists.

Design of percutaneous transluminal coronary angioplasty balloon catheters.

Background: Eight commercially available percutaneous transluminal coronary angioplasty (PTCA), including semi-compliant and non-compliant balloons, have been assessed in detail on their tip, balloon, shaft, RX-Port, and hypotube design. Important performance characteristics such as tip deformation, balloon elongation, and deflation rate have been quantified.

Methods: Five catheters of each model were evaluated during various tests.

Inverse Finite Element Approach to Identify the Post-Necking Hardening Behavior of Polyamide 12 under Uniaxial Tension.

Finite-element (FE) simulations that go beyond the linear elastic limit of materials can aid the development of polymeric products such as stretch blow molded angioplasty balloons. The FE model requires the input of an appropriate elastoplastic material model. Up to the onset of necking, the identification of the hardening curve is well established.

Temperature-dependent tensile properties of polyamide 12 for the use in percutaneous transluminal coronary angioplasty balloon catheters.

Background: Percutaneous transluminal coronary angioplasty (PTCA) balloon catheters must withstand high pressures required for the lesion treatment, pushing loads during insertion, and pulling loads during withdrawal. These loads pose a challenge especially for polymeric tubular shafts with small cross sections. In order to enable new design innovations and to better understand the mechanics of current catheter technologies, the tensile properties of polyamide (PA) 12 were investigated.

A Robot Mimicking Heart Motions: An Ex-Vivo Test Approach for Cardiac Devices.

Purpose: The pre-clinical testing of cardiovascular implants gains increasing attention due to the complexity of novel implants and new medical device regulations. It often relies on large animal experiments that are afflicted with ethical and methodical challenges. Thus, a method for simulating physiological heart motions is desired but lacking so far.

Implications of Wound Healing on Subcutaneous Photovoltaic Energy Harvesting.

Objective: Cardiac pacemakers must be regularly replaced due to depleted batteries. A possible alternative is proposed by subcutaneous photovoltaic energy harvesting. The body's reaction to an implant can cause device encapsulation.

Potential of subdermal solar energy harvesting for medical device applications based on worldwide meteorological data.

Significance: Active implants require batteries as power supply. Their lifetime is limited and may require a second surgical intervention for replacement. Intracorporal energy harvesting techniques generate power within the body and supply the implant.

A miniaturized endocardial electromagnetic energy harvester for leadless cardiac pacemakers.

Life expectancy of contemporary cardiac pacemakers is limited due to the use of an internal primary battery. Repeated device replacement interventions are necessary, which leads to an elevated risk for patients and an increase of health care costs. The aim of our study is to investigate the feasibility of powering an endocardial pacemaker by converting a minimal amount of the heart's kinetic energy into electric energy.

Unexpected high failure rate of a specific MicroPort/LivaNova/Sorin pacing lead.

Background: Pacing leads are the Achilles heel of pacemakers. Most manufacturers report a 3-year survival rate of >99% of their leads. We observed several failures of the Beflex/Vega leads (MicroPort, Shanghai, China; formerly Sorin/LivaNova).

Fat Oxidation Kinetics Is Related to Muscle Deoxygenation Kinetics During Exercise.

Purpose: The present study aimed to determine whether whole-body fat oxidation and muscle deoxygenation kinetics parameters during exercise were related in individuals with different aerobic fitness levels.

Methods: Eleven cyclists [peak oxygen uptake ( ): 64.9 ± 3.

Intracardiac Turbines Suitable for Catheter-Based Implantation-An Approach to Power Battery and Leadless Cardiac Pacemakers?

Objective: Cardiac pacemakers are powered by batteries, which become exhausted after a few years. This is a problem in particular for leadless pacemakers as they are difficult to explant. Thus, autonomous devices powered by energy harvesters are desired.

Radiofrequency ablation lesion assessment using optical coherence tomography - a proof-of-concept study.

Background: Radiofrequency catheter ablation (RFA) is an effective treatment for atrial fibrillation. However, ablation lesions are usually only assessed functionally. The immediate effect of RFA on the tissue is not directly visualized.

Leadless cardiac resynchronization therapy: An in vivo proof-of-concept study of wireless pacemaker synchronization.

Background: Contemporary leadless pacemakers (PMs) only feature single-chamber ventricular pacing. However, the majority of patients require dual-chamber pacing or cardiac resynchronization therapy (CRT). Several leadless PMs implanted in the same heart would make that possible if they were able to synchronize their activity in an efficient, safe, and reliable way.

Leadless Dual-Chamber Pacing: A Novel Communication Method for Wireless Pacemaker Synchronization.

Contemporary leadless pacemakers only feature single-chamber pacing capability. This study presents a prototype of a leadless dual-chamber pacemaker. Highly energy-efficient intrabody communication was implemented for wireless pacemaker synchronization.

An Intracardiac Flow Based Electromagnetic Energy Harvesting Mechanism for Cardiac Pacing.

Contemporary cardiac implantable electronic devices such as pacemakers or event recorders are powered by primary batteries. Device replacement due to battery depletion may cause complications and is costly. The goal of energy harvesting devices is to power the implant with energy from intracorporeal power sources such as vibrations and blood flow.

Endocardial Energy Harvesting by Electromagnetic Induction.

Objective: cardiac pacemakers require regular medical follow-ups to ensure proper functioning. However, device replacements due to battery depletion are common and account for ∼25% of all implantation procedures. Furthermore, conventional pacemakers require pacemaker leads which are prone to fractures, dislocations or isolation defects.

Energy Harvesting by Subcutaneous Solar Cells: A Long-Term Study on Achievable Energy Output.

Active electronic implants are powered by primary batteries, which induces the necessity of implant replacement after battery depletion. This causes repeated interventions in a patients' life, which bears the risk of complications and is costly. By using energy harvesting devices to power the implant, device replacements may be avoided and the device size may be reduced dramatically.

Towards Batteryless Cardiac Implantable Electronic Devices-The Swiss Way.

Energy harvesting devices are widely discussed as an alternative power source for todays active implantable medical devices. Repeated battery replacement procedures can be avoided by extending the implants life span, which is the goal of energy harvesting concepts. This reduces the risk of complications for the patient and may even reduce device size.

[Future cardiac pacemakers – technical visions].

Cardiac pacemakers are routinely used for the treatment of bradyarrhythmias. Contemporary pacemakers are reliable and allow for a patient specific programming. However, pacemaker replacements due to battery depletion are common (~25 % of all implantation procedures) and bear the risk of complications.

Corticotomy-Assisted Le Fort I Osteotomy: An Alternative to Segmentation of the Maxilla in Orthognathic Surgery.

Purpose: The aim of this study was to describe a surgical technique that can be used to solve dentofacial deformities associated with narrow interradicular spaces of the anterior teeth of the maxilla and inadequate overbite/overjet seen in hand-articulated models. This is presented here as an alternative to segmentation of the maxilla in Le Fort I osteotomy.

Methods: Six patients with dentofacial deformities (classes II and III malocclusions) had Le Fort I osteotomy accompanied by buccal alveolar corticotomies of the maxilla.

The first batteryless, solar-powered cardiac pacemaker.

Background: Contemporary pacemakers (PMs) are powered by primary batteries with a limited energy-storing capacity. PM replacements because of battery depletion are common and unpleasant and bear the risk of complications. Batteryless PMs that harvest energy inside the body may overcome these limitations.

Successful pacing using a batteryless sunlight-powered pacemaker.

Aims: Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications.