Conceptual Design and Procedure for an Autonomous Intramyocardial Injection Catheter

Trials and tribulations of cell therapy for heart failure: an update on ongoing trials

Heart failure (HF) remains a leading cause of mortality, responsible for 13% of all deaths worldwide. The prognosis for patients with HF is poor, with only a 50% survival rate within 5 years. A major challenge of ischaemia-driven HF is the loss of cardiomyocytes, compounded by the minimal regenerative capacity of the adult heart. To date, replacement of irreversibly damaged heart muscle can only be achieved by complete heart transplantation. In the past 20 years, cell therapy has emerged and evolved as a promising avenue for cardiac repair and regeneration. During this time, cell therapy for HF has encountered substantial barriers in both preclinical studies and clinical trials but the field continues to progress and evolve from lessons learned from such research. In this Review, we provide an overview of ongoing trials of cell-based and cell product-based therapies for the treatment of HF. Findings from these trials will facilitate the clinical translation of cardiac regenerative and reparative therapies not only by evaluating the safety and efficacy of specific cell-based therapeutics but also by establishing the feasibility of novel or underexplored treatment protocols such as repeated intravenous dosing, personalized patient selection based on pharmacogenomics, systemic versus intramural cell delivery, and epicardial engraftment of engineered tissue products.

Cell Therapy in the Treatment of Coronary Heart Disease

Heart failure is a leading cause of death in patients who have suffered a myocardial infarction. Despite the timely use of modern reperfusion therapies such as thrombolysis, surgical revascularization and balloon angioplasty, they are sometimes unable to prevent the development of significant areas of myocardial damage and subsequent heart failure. Research efforts have focused on developing strategies to improve the functional status of myocardial injury areas. Consequently, the restoration of cardiac function using cell therapy is an exciting prospect. This review describes the characteristics of various cell types relevant to cellular cardiomyoplasty and presents findings from experimental and clinical studies investigating cell therapy for coronary heart disease. Cell delivery methods, optimal dosage and potential treatment mechanisms are discussed.

Contact force sensors in minimally invasive catheters: current and future applications

INTRODUCTION

Advances in catheter design for minimally invasive surgery have brought about the incorporation of contact force (CF) sensors in catheters. Two main approaches to achieve CF sensing at the catheter end-effector consist of fiber optic or magnetic solutions. CF sensing feedback can be used to assist in ablation procedures, mapping cardiac regions, identifying tissue characteristics, and enhancing robotic catheter control.

AREAS COVERED

This review covers the technological and clinical aspects of CFS in catheters. Contact force and force-time integral thresholds for ablation procedures, procedural complications, and electroanatomical mapping strategies are discussed. Future applications of improving catheter control, minimizing complications, and enhancing mapping techniques through CF are examined.

EXPERT OPINION

Fiber optic CF catheters may be more desirable compared to magnetic modalities due to the lower cost, compactness, and higher accuracy. In ablation procedures, complications due to higher ablation duration, power, contact force, and force time can be reduced through practical experience and informed training for catheter operators. Future prospects consist of the incorporation of CF sensors with remote catheter systems to assist in catheter control. We propose that CF can also be used in machine learning decision-making algorithms to prevent complications or improve tissue characterization.

Feedforward Coordinate Control of a Robotic Cell Injection Catheter

Remote and robotically actuated catheters are the stepping-stones toward autonomous catheters, where complex intravascular procedures may be performed with minimal intervention from a physician. This article proposes a concept for the positional, feedforward control of a robotically actuated cell injection catheter used for the injection of myogenic or undifferentiated stem cells into the myocardial infarct boundary zones of the left ventricle. The prototype for the catheter system was built upon a needle-based catheter with a single degree of deflection, a 3-D printed handle combined with actuators, and the Arduino microcontroller platform. A bench setup was used to mimic a left ventricle catheter procedure starting from the femoral artery. Using Matlab and the open-source video modeling tool Tracker, the planar coordinates (y, z) of the catheter position were analyzed, and a feedforward control system was developed based on empirical models. Using the Student’s t test with a sample size of 26, it was determined that for both the y- and z-axes, the mean discrepancy between the calibrated and theoretical coordinate values had no significant difference compared to the hypothetical value of µ = 0. The root mean square error of the calibrated coordinates also showed an 88% improvement in the z-axis and 31% improvement in the y-axis compared to the unmodified trial run. This proof of concept investigation leads to the possibility of further developing a feedfoward control system in vivo using catheters with omnidirectional deflection. Feedforward positional control allows for more flexibility in the design of an automated catheter system where problems such as systemic time delay may be a hindrance in instances requiring an immediate reaction.