Dynamic Load Model Systems of Tendon Inflammation and Mechanobiology.

Dynamic loading is a shared feature of tendon tissue homeostasis and pathology. Tendon cells have the inherent ability to sense mechanical loads that initiate molecular-level mechanotransduction pathways. While mature tendons require physiological mechanical loading in order to maintain and fine tune their extracellular matrix architecture, pathological loading initiates an inflammatory-mediated tissue repair pathway that may ultimately result in extracellular matrix dysregulation and tendon degeneration.

An incubatable direct current stimulation system for in vitro studies of Mammalian cells.

The purpose of this study was to provide a simplified alternative technology and format for direct current stimulation of mammalian cells. An incubatable reusable stimulator was developed that effectively delivers a regulated current and does not require constant monitoring.

A screening technique useful for testing the effectiveness of novel "self-cleaning" photocatalytic surfaces.

We describe a screening methodology that can be used to quickly determine the effectiveness of newly synthesized photocatalysts. We were particularly interested in measuring the destruction of organic molecules painted onto a photocatalytic surface by spraying, with destruction proceeding in ambient air (as a model for airborne toxin destruction). Our method can utilize photocatalysts that are synthesized as powders (such as doped and undoped titanium oxide) and which are then calcined onto a glass substrate disk at 600°C.

The effect of an electronic control device on muscle injury as determined by creatine kinase enzyme.

The medical literature on the effect of electronic control devices (ECD) on muscle injury is sparse. In this paper, we examine pooled data from five human studies that used creatine kinase (CK) as a marker for muscle injury. CK was measured in five separate studies involving four TASER ECDs with different exposure durations and number of circuits or contact points.

The physiologic effects of multiple simultaneous electronic control device discharges.

Objectives: Law enforcement and military personnel use electronic control devices to control non-compliant and actively resistive subjects. The TASER((R)) Shockwave is a new electronic control device designed specifically as an area denial device capable of delivering multiple simultaneous discharges. This is the first study to examine the effects of multiple simultaneous device discharges in humans.

Theoretical comparisons of nerve and muscle activation by neuromuscular incapacitation devices.

In this study important aspects of the TASER(R) M26 and X26 neuromuscular incapacitation device waveforms are simulated, analyzed and contrasted against electrical stimulation with rectangular waveforms (commonly used in therapeutic stimulation devices). Expected skeletal muscle forces evoked by M26 and X26 stimulation are simulated also and compared against forces expected with higher or lower frequency trains. The first half-cycle of the M26 damped 50 kHz sinusoidal wave is the main contributor to stimulation threshold with this device.

Receptive field characteristics under electrotactile stimulation of the fingertip.

Skin on human fingertips has high concentrations of mechanoreceptors, which are used to provide fine resolution tactile representations of our environment. Here, we explore the ability to discriminate electrotactile stimulation at four sites on the fingertip. Electrical stimulation was delivered to arrays of electrodes centered on the index fingertip (volar aspect).

Extended charge banking model of dual path shocks for implantable cardioverter defibrillators.

Background: Single path defibrillation shock methods have been improved through the use of the Charge Banking Model of defibrillation, which predicts the response of the heart to shocks as a simple resistor-capacitor (RC) circuit. While dual path defibrillation configurations have significantly reduced defibrillation thresholds, improvements to dual path defibrillation techniques have been limited to experimental observations without a practical model to aid in improving dual path defibrillation techniques.

Methods: The Charge Banking Model has been extended into a new Extended Charge Banking Model of defibrillation that represents small sections of the heart as separate RC circuits, uses a weighting factor based on published defibrillation shock field gradient measures, and implements a critical mass criteria to predict the relative efficacy of single and dual path defibrillation shocks.

Finite element modeling of electric field effects of TASER devices on nerve and muscle.

TASERs deliver electrical pulses that can temporarily incapacitate subjects. The goal of this paper is to analyze the distribution of currents in muscle layers and understand the electro-muscular incapacitation safety and efficacy of TASERs. The analyses describe skeletal muscle and motor nerve activation, cell electroporation and current and electric field distributions through skin, fat and muscle layers, under worst-case assumptions for TASER electrode penetration and separation.

Performance of dynamic and isovolumetric trained skeletal muscle ventricles.

Background: Dynamic training and maintaining muscle tension are important factors during skeletal muscle ventricle (SMV) conditioning that may improve SMV performance. This study sought to determine the effects of dynamic muscle training and progressive SMV resting pressure expansion on SMV pumping capability.

Materials And Methods: SMVs were constructed in 14 goats using the left latissimus dorsi muscle.

Is skeletal muscle ventricle chronic stability dependent on wall stress? Design implications.

Chronic skeletal muscle ventricle (SMV) stability is essential for clinical implementation. SMVs in animal models have chronically expanded or collapsed when exposed to physiologic pressures. SMV wall stress is a more appropriate indicator than pressure or geometry to compare SMVs between studies.

Effect of rapid biphasic shock subpulse switching on ventricular defibrillation thresholds.

Introduction: The aim of this study was to demonstrate that significant reductions in defibrillation threshold (DFT) can be achieved by rapidly switching defibrillation pulses within an overall biphasic envelope between multiple endovascular electrode sets.

Methods And Results: Defibrillation electrodes were implanted in four locations in nine anesthetized swine (41.7 +/- 8.

Linear performance characteristics of latissimus dorsi muscle: potential for cardiac assistance.

Knowledge of the quantitative performance capabilities of skeletal muscle in a linear geometry is necessary to predict the performance and to optimize the design of linearly configured, skeletal muscle powered cardiac assist devices (MCADs). This study determined the performance characteristics of goat latissimus dorsi muscle (LDM) using a linear, ex vivo experimental apparatus. In five goats, the LDM (130.

Skeletal muscle ventricle pressure-volume properties conform to dynamic and static conditioning.

Background: Chronic changes in skeletal muscle ventricle (SMV) size and strength can directly affect performance and stability. These changes may depend on the conditioning protocol or implant system. Therefore the effects of conditioning protocols on SMV geometry and contractility must be identified for optimal SMV design and application.