Abstract Although materials and engineered surfaces are broadly utilized in creating assays and devices with wide applications in diagnostics, preservation of these immuno-functionalized surfaces on microfluidic devices remains a significant challenge to create reliable repeatable assays that would facilitate patient care in resource-constrained settings at the point-of-care (POC), where reliable electricity and refrigeration are lacking. To address this challenge, we present an innovative approach to stabilize surfaces on-chip with multiple layers of immunochemistry. The functionality of microfluidic devices using the presented method is evaluated at room temperature for up to 6-month shelf life. We integrated the preserved microfluidic devices with a lensless complementary metal oxide semiconductor (CMOS) imaging platform to count CD4 + T cells from a drop of unprocessed whole blood targeting applications at the POC such as HIV management and monitoring. The developed immunochemistry stabilization method can potentially be applied broadly to other diagnostic immuno-assays such as viral load measurements, chemotherapy monitoring and biomarker detection for cancer patients at the POC.
In this study, controllability, safety, blood cell depletion, and hemolysis of a pulsatile roller pump in high-risk patients was evaluated. Sarns 8000 roller pump (Sarns, Terumo CVS, Ann Arbor, MI, USA) with a pulsatile control module was used as arterial pump in a clinical setting. Forty patients undergoing elective open heart surgery with high-risk either having chronically obstructive pulmonary disease or chronic renal failure were randomly included in the study to be operated on using pulsatile perfusion or non-pulsatile perfusion. Blood samples were withdrawn at induction of anesthesia, at the time of aortic clamping and de-clamping and at 1 hour and 24 hours following cessation of the bypass. Hematocrit and plasma free hemoglobin values were measured. We observed that the pulsatile roller pump perfusion and the extracorporeal circuit used in the clinical study is safe in high-risk patients undergoing cardiopulmonary bypass. We did not face any emboli, hemolysis, or technical problems. Pulsatile roller pump perfusion with Sarns 8000 heart-lung machine is a simple and reliable technique and can be easily applied during open heart surgery.
In this study, the blood compatibility of the tip-to-tip coated and flow-optimized extracorporeal circuits were investigated using poly(2-methoxyethylacrylate) PMEA-coated oxygenators and tubing sets. Total protein, human serum albumin, fibrinogen, erythrocyte, leukocyte and platelets loss quantities were analyzed on blood samples withdrawn five different times during cardiopulmonary bypass (CPB) such as: baseline (T1), during CPB (T2), end of CPB (T3), after protamine injection (T4) and intensive care (T5), no fibrinogen loss was observed for the tip-to-tip coated system. After an operation, protein desorption assays from fiber surfaces of the tip-to-tip coated and flow-optimized extracorporeal circuits showed very little desorption. Less protein desorption was found between sonicated fibers and fiber sample solutions at <0.2mg/dL and 0.58mg/dL, respectively. For tip-to-tip coated and flow-optimized extracorporeal system, no platelet aggregation and no erythrocyte, leukocyte losses were observed. Optimized flow path and eliminated straight turns due to integration of exchangers minimized turbulent flows. Larger surface areas of the fibers optimized blood flow speed and improved gentle flow conditions and lowered shear stress. Clinically, no excessive postoperative bleeding was observed by the patients with the tip-to-tip coated system after 24 hours (hemorrhage was 387mL). The average unit of red blood cell and fresh frozen plasma transfusions were 0.98 and 2.10 units, respectively. Differences in adsorbed HSA on the hollow fiber surfaces were examined by STM which indicated that less protein existed on the sample solution of the non-sonicated fiber surfaces.
With the advancements in wireless technology and digital electronics, some tiny devices have started to be used in numerous areas in daily life. These devices are capable of sensing, computation and communicating. They are generally composed of low power radios, several smart sensors and embedded CPUs (Central Processing Units). These devices are used to form wireless sensor network (WSN) which is necessary to provide sensing services and to monitor environmental conditions. In parallel to WSNs, the idea of internet of things (IoT) is developed where IoT can be defined as an interconnection between identifiable devices within the internet connection in sensing and monitoring processes. This paper presents detailed overview of WSNs. It also assesses the technology and characteristics of WSNs. Moreover, it provides a review of WSN applications and IoT applications.
Phenylketonuria (PKU) is an inborn error of metabolism which arises from the mutations in phenylalanine hydroxylase (PAH) gene. PAH enzymes hydroxylate phenylalanine to tyrosine in the presence of the cofactor tetrahydrobiopterin (BH4), molecular oxygen and iron. Mutations in PAH gene led to lack of one of the essential enzymes, phenylalanine hydroxylase (PAH). Lack of this crucial enzyme brings about the accumulation of L-phenylalanine and their metabolites in the newborns’ blood, urine and other body fluids, causing skin lesions, epilepsy, microcephaly, eczema, and scleroderma and, if untreated, also cause mental retardation. The amount of serum phenylalanine of healthy individual, is expected to be measured in the range of 50-110 μM, while phenylalanine in phenylketonuria patients is in the range of 0.6-3.8 mM in serum and 20-60 mM in urine. Metabolic diseases such as phenylketonuria are rare diseases but these types of illness reduce the quality of life at serious levels. If these diseases can be diagnosed early by the help of detection methods, mortality and morbidity can be prevented. For this reason, early diagnosis of metabolic diseases provides a better quality of life for the patients. Today, phenylketonuria could be determined using microbial inhibition, chromatographic and spectrophotometric methods. In Turkey, phenylketonuria test is performed by colorimetric method in screening centers. However, since these methods are time-consuming and expensive, complex instrumentation, preliminary preparation and special laboratory facilities are needed, the need in this area cannot be fully met. For this reason, there is an urgent need to develop simpler, faster and more economical assay methods and make them readily available at the clinic. For this reason, the development of new techniques and/or devices is a great need to be addressed urgently. In this context, use of affinity biosensors which are known with their sensitivity, selectivity, low cost and rapid response, to the following of phenylketonuria disease will ensure that these disadvantages are overcome. This review aims at presenting the bioreceptors to selectively and sensitively diagnose phenylketonuria by using different transducers in affinity biosensors.
The purpose of this study was to investigate the effects of pulsatile and non-pulsatile cardiopulmonary bypass (CPB) in high risk patients. We compared clinical, hemodynamic, biochemical and hematologic parameters, arterial and venous blood gases, urine output, complement proteins, TNF-/spl alpha/, interleukins and S100/spl beta/ protein before the initiation of CPB, at the times of aortic cross-clamping and de-clamping, at Postoperative 1/sup st/ and 24/sup th/ hours. We concluded that pulsatile blood flow during CPB has favourable influence on inflamatory, physiologic and hematologic parameters in patients who have high risk for open heart surgery.
Deep learning has been studied extensively for driver drowsiness detection using video data. However, since the proposed deep learning methods are computationally cumbersome, the commercial driver drowsiness detection methods are still using hand-crafted features such as lane deviation and percentage of eye closure. This study investigates a deep learning model that provides a fair drowsiness detection performance with a lightweight architecture. In the proposed method, Dlib library was used to detect the driver's face in individual frames of video data. The detected faces are fed into a pre-defined convolutional neural network architecture. Then, a long short-term memory network was used to capture the temporal information between the frame sequences to assess the state of drowsiness. The proposed model achieves a detection accuracy of 80% in a popular benchmark dataset. It was also verified that the model could be implemented on a commercial and inexpensive development board with a frame rate of 5 frames per second.
Inflammation is the primary problem associated with blood-contacting artificial organs. Leucocytes play an essential role in the generation of the inflammatory response. Inflammation can be defined in a variety of ways. The goal of this research is to develop a biosensor system that is less complicated and faster responding than conventional methods. In this study, highly sensitive QCM crystals were chemically modified to measure changes in adsorbed mass on the surface and were used to detect activated neutrophils. Leucocyte activation was quantified by measuring the change in frequency of the QCM. QCM crystals with immobilized anti-C3a were tested in vitro using different concentrations of neutrophils. The measured frequency shifts were proportional to neutrophil number, indicating that activated neutrophils attach to the surface of the QCM. These results were supported by AFM surface topography measurements and SEM images. This method presents a rapid, inexpensive, and easy bioassay that tests the inflammatory response to blood-contacting artificial organs.
Realization of interventional therapeutic procedures with guidance of Magnetic Resonance Imaging (MRI) is a promising novelty in area of interventional surgery because of eliminating x-ray exposure to patient body. Together with radiation free nature, advances in MRI techniques present superior soft tissue contrast and real time physiologic parameters from related tissue. However, the strong static magnetic field, magnetic radiofrequency (RF) pulses, and time-varying gradient fields applied during MRI, may result in exceeded heating risk over interventional instruments and adjacent tissue inside patient body. Additionally, since real time tracking and determination of device position inside patient body is critical for operators, sufficient visibility under MRI is another challenging issue to overcome. Therefore, proper biomaterials must be utilized for designing and development of MRI compatible interventional instruments by considering many factors including biocompatibility, MRI safety, MRI visibility, and other mechanical needing.
