Integrating functional and anatomical information to facilitate cardiac resynchronization therapy

Multiple imaging modalities are required in patients receiving cardiac resynchronization therapy. We have developed a strategy to integrate echocardiographic and angiographic information to facilitate left ventricle (LV) lead position. Full three-dimensional LV-volumes (3DLVV) and dyssynchrony maps were acquired before and after resynchronization. At the time of device implantation, 3D-rotational coronary venous angiography was performed. 3D-models of the veins were then integrated with the pre- and post-3DLVV. In the case displayed, prior to implantation, the lateral wall was delayed compared to the septum. The LV lead was positioned into the vein over the most delayed region, resulting in improved LV synchrony.     

Utility of the INTERMACS profile at the time of assessment for heart transplant

The Interagency Registry of Mechanically Assisted Circulatory Support (INTERMACS) profiles are associated with mortality in heart failure patients undergoing ventricular assist device (VAD) implantation and heart transplantation (HTx). We assessed the prognostic value of the INTERMACS profile at the time of assessment for HTx or durable VAD implantation as bridge to candidacy (BTC). A total of 503 consecutive patients considered for HTx or VAD between 2006 and 2016 were included. The associations between INTERMACS profile and (a) waitlist mortality or delisting, (b) probability of HTx, and (c) overall mortality or delisting were evaluated using multivariable analysis. Median follow-up time was 2.9 years (IQR: 0.9-5.5) during which 184 received VAD, 347 received HTx, and 73 died (27 waitlist, 46 post-transplant). INTERMACS I-II profile was associated with higher waitlist mortality or delisting (HR: 3.83, 95% CI: 1.22-12.03), and this risk was reversed by VAD implantation (HR: 0.12, 95% CI: 0.03-0.50). INTERMACS III-IV profile was associated with a higher probability of HTx (HR: 1.82, 95% CI: 1.37-2.40). INTERMACS profile was not associated with the composite outcome of overall mortality or delisting. These results emphasize the prognostic utility of INTERMACS at time of decision for advanced therapies and its potential value in selecting patients for different interventions.     

A novel approach to formulation factor of aceclofenac eye drops efficiency evaluation based on physicochemical characteristics of in vitro and in vivo permeation

The purpose of the present study was to evaluate aceclofenac eye drop through excised goat cornea. Raising pH of the formulation from 6.0 to 8.0, effect of different preservatives or effect of viscosity enhancer decreases apparent permeability coefficient. Topical ophthalmic NSAID are used to treat ocular surface and anterior segment inflammation as well as post operative management of pain and inflammation. Aceclofenac’s unique chemical structure makes it both a potent anti inflammatory drug and lipophilic molecule that penetrates ocular tissue, ensuring relief of pain in cataract and refractive surgery and corneal abrasion. The octanol/water partition coefficient of aceclofenac drug is 1.86 ± 0.75. Permeation characteristics of the drug were evaluated by putting 1 ml formulation on freshly excised goat cornea fixed between donor and receptor compartments of an all-glass modified Franz diffusion cell and measuring the drug permeated in the receptor by spectrophotometry at 275 nm, after 120 min. The results suggest that aceclofenac ophthalmic solution (pH 7) containing BAC provides increased in vitro ocular availability through goat corneas. The combination of methyl paraben and propyl paraben MP–PP preservative in aceclofenac ophthalmic eye drop 0.1% formulated in phosphate buffer increases transcorneal permeation. The developed formulations were evaluated for their pharmacodynamics in albino rabbits, by measuring in-vivo study and were compared to a marketed voltrane ophthalmic solution.     

Effect of Ankle Torque on the Ankle–Foot Orthosis Joint Design Sustainability

The ankle joint of a powered ankle–foot orthosis (PAFO) is a prominent component, as it must withstand the dynamic loading conditions during its service time, while delivering all the functional requirements such as reducing the metabolic effort during walking, minimizing the stress on the user’s joint, and improving the gait stability of the impaired subjects. More often, the life of an AFO is limited by the performance of its joint; hence, a careful design consideration and material selection are required to increase the AFO’s service life. In the present work, a compact AFO joint was designed based on a worm gear mechanism with steel and brass counterparts due to the fact of its large torque transfer capability in a single stage, enabling a compact joint. Further, it provided an added advantage of self-locking due to the large friction that prevents backdrive, which is beneficial for drop-foot recovery. The design was verified using nonlinear finite element analysis for maximum torque situations at the ankle joint during normal walking. The results indicate stress levels within its design performance; however, it is recommended to select high-grade structural steel for the ankle shaft as the highest stresses in AFO were located on it.