Recent Patents on Biomedical Engineering (Discontinued) - Volume 5, Issue 3, 2012

Many health problems remaining to be untreatable throughout the human history can be overcome by utilizing new biomedical materials. Healing cartilage defects is one of the problems causing significant health issue due to low regeneration capacity of the cartilage tissue. Scaffolds as three-dimensional functional networks provide promising tools for complete regeneration of the cartilage tissue. Diversity of materials and fabrication methods give rise to many forms of scaffolds including injectable and mechanically stable ones. Various approaches can be considered depending on the condition of cartilage defect. A scaffold should maintain tissue function within a short time, and should be easily applied in order to minimally harm the body. This review will cover several patents and other publications on materials for cartilage regeneration with an outlook on essential characteristics of materials and scaffolds.

Orthoses are a form of exoskeleton that attach to a limb or to the torso. Upper extremity orthoses have been developed in response to two distinct needs; improved rehabilitation therapy and devices that aid persons with disabilities in performing activities of daily living. In the past, therapists have provided therapy to those affected by conditions such as stroke by repetitive manipulation of the affected body segments. Several types of upper extremity orthoses have been developed which enable the therapist to increase the dosage and intensity of therapy. Orthoses have also been developed for persons with more permanent disabling conditions to improve their functional independence. These devices focus on enabling specific tasks that are usually associated the workplace or daily living. This article primarily reviews patents related to powered upper extremity orthoses used in rehabilitation or as assistive devices and their current applications. Concluding remarks explore possible future developments in both of these areas.

Congestive heart failure accounts for a high morbidity worldwide. The only effective treatment for end-stage patients is heart transplantation or, in light of the shortage of suitable donors, an artificial heart or ventricular assist device (VAD). The newer-generation continuous-flow rotary VADs allow for a significant reduction in size and an improvement in reliability. However, the invasive implantation still limits this technology from being offered to critically ill patients. To benefit more heart failure patients, there is a need to develop a long-term VAD which can be implanted via minimally invasive procedure. Recently, expandable/deployable devices have been investigated as a potential solution. Such a device can be inserted percutaneously via the peripheral vessels in its collapsed form and operate in its expanded form at the desired location. This paper reviews significant patents on foldable VADs using mechanical and/or material means. Mechanically folded structures adapt joints and links to facilitate the folding process whilst utilization of elastic materials allows the structure to be bent or twisted without permanent deformation. Current and future developments of foldable VADs are discussed. Foldable pumps could generate less blood damage and mechanical wear as compared to current miniature percutaneous VADs. Therefore, foldable VADs have the potential for longer-term application and minimally invasive insertion, providing a promising solution for heart failure patients.

Quantum dots (QDs) are nanometer-scale crystals, which have tunable fluorescence signatures, narrow emission spectra, brighter emissions and good photostability. These properties enable QDs as powerful inorganic fluorescent probes for biological applications, such as imaging (in vitro and in vivo), biosensing, biolabeling, gene expression studies, protein studies or medical diagnostics. High quality QDs are usually synthesized in nonpolar solvents with hydrophobic coatings. For in vivo applications, QDs have been surface modified by substituting their hydrophobic coating molecules with various hydrophilic capping agents of biofunctional linkers. This article focuses on recent patents on the preparation of QDs and potential applications in biomedicine, including core-shell QDs, water-soluble QDs, biofunctionalized QDs and encapsulated QDs. Energy transfer between QDs and dye acceptors has been reported through fluorescence resonance energy transfer or bioluminescence resonance energy transfer technologies.

Heart valve disease is a serious problem, especially in aging societies. If left untreated, many patients can die from the disease itself or complications associated with it. However, many are denied open-heart replacement surgeries due to advanced age and co-morbidities. Thus, other solutions had to be explored. One successful solution is transcatheter heart valve implantation and is now seen as the only viable treatment. Transcatheter heart valve implantation is a minimally invasive technique of inserting an artificial heart valve by means of a catheter without requiring open heart surgery. However, challenges are always there with every successful technology. Obstacles that need to be overcome include anatomical constraints, appropriate delivery technique, satisfactory performance of the transcatheter heart valve and so on. In this review, these challenges associated with aortic and mitral valve will be analyzed due to the prevalence of the diseases associated with them. On top of that, design considerations, hemodynamic performance and current stateof- the-art and recent patents of aortic and mitral valves are discussed, with particular emphasis on their engineering aspects.

In medicine, exploration of the digestive tract by non-invasive means is designed to improve patient monitoring. Exfoliated epithelial cells can be isolated from several body fluids (i.e., breast milk, urines, and digestive fluids) as a cellular mixture (senescent, apoptotic, proliferative, or quiescent cells). Exfoliation is a phenomenon that participates in the maintenance and evolution of the mucosal architecture. By quantifying the degree of this phenomenon, i.e. by assessing the loss of epithelial cells or closely related molecular compounds from the gut mucosa, it is possible to evaluate pharmacological or nutritional stress in clinics as well as during epidemiological surveillance. Two methods have been proposed to obtain relevant biological information from exfoliated epithelial cells. The first is based on microscopic examination and the immunophenotyping of parietal cells isolated from gastric fluids aspirates. The second proposes to recover all eucaryote transcripts to perform microarray analysis. This minireview will introduce recent methodological developments and patents in the field of gastrointestinal exfoliation.

In ultrasound imaging, radiologists often need to attain different penetration depths. It is well known that the maximum penetration depth decreases when the frequency of the ultrasound increases. Based on related research and reviewing of recent patents, we suggest an approach based on Golay coding to improve the penetration depth. During our simulations, we successfully achieved a maximum penetration depth of 60 cm as the frequency ranged from 0.0625 to 4 MHz with uniform signal to noise ratio of 6 dB. Implementing this result will mean that a unique 4 MHz transducer can be used for a variety of examinations where probes of different frequencies were needed.