Publications by authors named "Melur Ramasubramanian"

This study aims to develop an organ-on-a-chip model, intervertebral Disc-on-a-Chip, to investigate integrated effects of mechanical loading and nutrition on disc health. The system consists of a detachable multilayer microfluidic chip, a Computer-Arduino-based control system, and a mechanical loading unit, which were optimized for accurate axial force measurement and the maintenance of a 21-day disc culture. To ensure accuracy of axial force, we optimized the axial mechanical loading regimen, used the Computer-Arduino-based system and low-profile force sensors (LPFS) to control the mechanical loading unit, and modeled the force distribution by using computational simulation.

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Smartphone technology has been recently applied for biomedical image acquisition and data analysis due to its high-quality imaging capability, and flexibility to customize multi-purpose apps. In this work, we developed and characterized a smartphone-microfluidic fluorescence imaging system for studying the physiology of pancreatic islets. We further evaluated the system capability by performing real-time fluorescence imaging on mouse islets labeled with either chemical fluorescence dyes or genetically encoded fluorescent protein indicators (GEFPIs).

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Islet beta-cell viability, function, and mass are three decisive attributes that determine the efficacy of human islet transplantation for type 1 diabetes mellitus (T1DM) patients. Islet mass is commonly assessed manually, which often leads to error and bias. Digital imaging analysis (DIA) system has shown its potential as an alternative, but it has some associated limitations.

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Mechanical loading plays an important role in maintaining disc health and function, and in particular, excessive mechanical loading has been identified as one of major reasons of disc degeneration. Intervertebral disc organ culture serves as a valuable tool to study disc biology/pathology. In this study, we report the development and validation of a new mouse disc organ culture system by dynamically applying compression loading in a customized micro-culture device tailored for mouse lumbar discs.

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Bioartificial pancreas made of insulin-secreting islets cells holds great promise in the treatment of individuals with Type-1 diabetes. Successful islet cell microencapsulation in biopolymers is a key step for providing immunoisolation of transplanted islet cells. Because of the variability in the size and shape of pancreatic islets, one of the main obstacles in their microencapsulation is the inability to consistently control shape, size, and microstructure of the encapsulating biopolymer capsule.

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This paper summarizes the discussions held during the First IEEE Life Sciences Grand Challenges Conference, held on October 4-5, 2012, at the National Academy of Sciences, Washington, DC, and the grand challenges identified by the conference participants. Despite tremendous efforts to develop the knowledge and ability that are essential in addressing biomedical and health problems using engineering methodologies, the optimization of this approach toward engineering the life sciences and healthcare remains a grand challenge. The conference was aimed at high-level discussions by participants representing various sectors, including academia, government, and industry.

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Current applications of the microencapsulation technique include the use of encapsulated islet cells to treat Type 1 diabetes, and encapsulated hepatocytes for providing temporary but adequate metabolic support to allow spontaneous liver regeneration, or as a bridge to liver transplantation for patients with chronic liver disease. Also, microcapsules can be used for controlled delivery of therapeutic drugs. The two most widely used devices for microencapsulation are the air-syringe pump droplet generator and the electrostatic bead generator, each of which is fitted with a single needle through which droplets of cells suspended in alginate solution are produced and cross-linked into microbeads.

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Horizontal axis washing machines are water and energy efficient and becoming popular in the USA. Unlike a vertical axis washer, these do not have an agitator and depend solely on tumbling for the agitation of laundry during the wash cycle. However, due to the constant shifting of laundry during washing, the load distribution is often unbalanced during the high speed spin cycle.

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In this paper, an integrated fiberoptic-microfluidic device for the detection of agglutination for blood type cross-matching has been described. The device consists of a straight microfluidic channel through with a reacted RBC suspension is pumped with the help of a syringe pump. The flow intersects an optical path created by an emitter-received fiber optic pair integrated into the microfluidic device.

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Human error is the most significant factor attributed to incompatible blood transfusions. A spectrophotometric approach to blood typing has been developed by examining the spectral slopes of dilute red blood cell (RBC) suspensions in saline, in the presence and absence of various antibodies, offering a technique for the quantitative determination of agglutination intensity [Transfusion39, 1051, 1999TRANAT0041-113210.1046/j.

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