Biomedical engineering advances最新文献

Microneedle (MN) patches are composed of micron-sized needles organised in arrays and attached to the backing of a patch. The most common type is the transdermal patch, designed to uniformly penetrate the stratum corneum to reach the dermis of the skin. Recent advances in 3D printing technology have allowed the development of reproducible, efficient methods to create microneedles on a large scale, which had previously been a factor in the limited clinical uptake. In comparison to conventional drug delivery methods, MN patches have been shown to significantly reduce pain and scar generation while maintaining effective and reliable delivery of vaccines, immunotherapies, and slow-release drug therapies. The MN design has also been investigated as an alternative to conventional tissue biopsy, with positive results. Synchronous delivery of medications while monitoring biomarkers in dermal interstitial fluid (ISF) is also a promising clinical development with wide-reaching benefits. MNs are diverse in design and material composition, and with developments in fabrication technology, transdermal drug delivery has been applied to many clinical fields, including chronic illnesses such as arthritis or diabetes, cancer, immunotherapies, epidemic disease prevention and ocular treatments. While the majority of MN patch applications are still in the pre-clinical testing phase in animal models, further translation of this technology to the clinic could aid in medication and vaccine compliance, improve treatment access in rural and remote communities, improve targeted therapy applications and provide financial cost savings to the public health sector. This review evaluates the designs and applications of current transdermal MN patches for drug delivery, biomarker monitoring and diagnostic biopsies compared to conventional needle-based methods.

Movement research has typically been performed using three-dimensional (3D) marker-based motion capture, which is considered the “gold-standard” for biomechanical assessment. However, limitations exist due to the lack of portability, extensive preparation for data collection, marker placement training, error due to marker movement, and possible skin irritation due to marker adhesives. There is inherent error due to motion artifact stemming from skin movement and differences in marker placement between testers. Markerless motion capture systems are emerging as a new method of kinematic assessment. These methods require little preparation and there is no need to alter participant clothing. Markerless motion capture has also been validated for the lower extremity in healthy older adults during gait. However, it has not been validated for other populations or for the assessment of upper extremity (UE) motion. Therefore, the purpose of this study was to examine differences in calculated UE kinematics between marker-based and a markerless motion capture system. Participants attended two data collection sessions. Marker-based and markerless motion capture data was collected simultaneously while participants completed the Box and Blocks test (BBT). Kinematic and spatiotemporal data from both systems was exported using identical time series to ensure the same conditions for comparisons. Intraclass Correlation Coefficients (ICCs) were calculated to determine between session reliability for both systems on range of motion and peak joint angular data to ensure movement variability was not affecting measurement consistency. ICCs and Bland Altman statistics were also calculated between the systems. Root mean square deviation (RMSD) values were determined between demeaned UE joint angles for the two systems to examine movement pattern differences. The resulting between-session ICCs for each system showed that the markerless system shared similar reliability during this task as the marker-based system, further supporting the effect of variability on between-session reliability. Between-system ICCs resulted in good (0.7<ICC<0.9) to excellent (ICC>0.9) agreement. Bland Altman results confirmed the existence of measurement bias between the systems. RMSD values for all UE joint angles were found to be less than 6°. Overall, the results from this study support the use of markerless motion capture in clinical settings to examine upper extremity biomechanics in children.

In practical applications, protein fouling studies often face limitations due to their reliance on single-protein feed experiments. It is crucial to acknowledge that interprotein interactions can significantly differ from intraprotein interactions, leading to variations in adsorption and membrane fouling behaviors. In this review, we delve into the dynamics of adsorption and membrane fouling, with a specific focus on single and binary solutions of Bovine Serum Albumin (BSA) and Lysozyme (LYZ) at or near physiological pH. These two proteins differ in terms of size, charge, and conformational stability, allowing for comparisons between small and large proteins, positively and negatively charged proteins, as well as rigid and flexible proteins. To gain further insights, we compare the findings from LYZ in single and binary solutions with those of alpha lactalbumin (α-LA), which, despite having opposite charges, shares a similar size with LYZ. The formation of BSA-LYZ heteroprotein complexes may introduce unique fouling trends in binary solutions compared to single solutions. This interplay can either enhance, reduce, or leave fouling unaffected. While studies employing the Extended DLVO (Derjaguin, Landau, Vervey, and Overbeek) theory to predict fouling in protein mixtures are limited, preliminary investigations using DLVO show promise. This approach has the potential to extend to binary and multi-protein feeds, providing valuable insights into the dynamics of fouling behavior in complex protein solutions. Considering that BSA is often used as a surrogate for Human Serum Albumin (HSA), the findings of this endeavor hold particular significance. HSA ranks the most abundant plasma proteins and, therefore, represents a crucial subject in numerous protein-related studies.

Upper limb amputations are frequently the result of traumatic events, often associated with car accidents or incidents involving industrial machinery. The development of prosthetic technologies is essential to provide physical assistance to amputees and offer psychological support. In such circumstances, cosmetic gloves can be utilized to improve personal and social comfort by enhancing visual characteristics similar to those of a biological hand. In this work, we developed formulations based on natural rubber latex (NRL) with antibacterial properties by the incorporation of an additive consisting of zinc oxide coated with silver nanoparticles to manufacture cosmetic gloves designed for upper limb prostheses. The dispersion efficiency of the additive was investigated by microscopic techniques. Tensile and tear strength tests, Shore A hardness measurements, swelling indices, hydrophobicity and inhibition of bacterial growth were also conducted to ascertain the suitability and adaptability of the developed material for integration into the daily activities of patients. Moreover, processing parameters for the immersion molding production of cosmetic gloves were assessed and validated, highlighting the crucial relationship between manufacturing techniques and material properties. Overall, the results indicated that the combination of the additive with a high crosslinking density of NRL effectively improved the material mechanical properties, resulting in a tensile strength of up to 20.7 MPa and a tear strength of approximately 40 kN m⁻¹. In addition, and according to the antibacterial tests, the gloves exhibited bacteriostatic effects against Staphylococcus aureus and bactericidal effects against Escherichia coli. As a conclusion, the dataset indicates that the manufactured cosmetic gloves can be used to covering upper limb prostheses. Additionally, it underscores the considerable potential for the cosmetic glove manufacturing industry through the use of appropriate formulations and processing techniques for NRL.

In health care, early detection of diseases is important in order to increase survival rates. Regular monitoring of vital signs is necessary for the early detection of health issues. Due to the high cost, inadequacy, and complexity of monitoring devices, it is challenging for individuals to check their vital signs at home. Consequently, a cost-effective, broadly accessible, and easy-to-use system is necessary for health monitoring. For this purpose, we developed a portable and wireless acquisition electronic device to help patients record physiologically relevant signals such as ECG, EMG, EEG, and EOG for continuous monitoring. The key components of the acquisition system are a portable device, a Wi-Fi router, a SQL server, and a graphical user interface (GUI). In this study, a cost-effective, fairly low-power Internet-of-Things (IoT)-based health monitoring system was built employing a portable device incorporating analog front ends (AFE) and the ESP 32 Wroom-32. Continuous remote monitoring and diagnostics are made possible by including IoT in the architecture. In the proposed monitoring system, the lightweight Message Queue Telemetry Transport (MQTT) protocol was used. A GUI is constructed that shows near-real-time data in a web browser and can be accessed from any operating system. The accuracy of the acquired signals was validated by comparing the individual’s ECG recorded in a remote device through the IoT cloud with a conventional biomedical certified ECG machine. The AFEs were built and evaluated based on the amplitude and bandwidth of ECG, EMG, EEG, and EOG signals. The cost and power analysis, as well as other key parameters are presented. Compared to similar existing boards, our developed system demonstrates high configurable sampling frequency, high Common Mode Rejection Ratio (CMRR) and high transmission throughput with no packet loss while costing significantly less and consuming moderate power. This makes the proposed system suited for the acquisition of multichannel physiological signals for home applications.

This paper discusses the concept and model to develop a prototype extracellular vesicle bulk-isolation device (EBID). It proposes an engineering design and potential ways to mitigate limitations in the currently available extracellular vesicle (EV) isolation techniques. A more convenient isolation technique is developed and presented to ensure production-scale isolation and purification of the specific size of EV (approximately 0.1 to 0.34 µm) from a large quantity of cell-culture media or biological fluid sources. A more appropriate design concept was established based on the chitosan-assisted precipitation of EV techniques and the membrane filtration technology-based prototype. After that, a novel theoretical model for bulk isolation of EVs was developed and presented using pressure-driven circulation and particulate flow in the EBID loop, where the EV production results from the biofluid flowing through the EBID membrane filter module (MFM). Governing equations are coupled with Darcy's law to investigate the biofluid flow behavior in the EBID MFM, therefore simulating the isolation process of EVs from their biofluids. The flow characteristics of the EV isolation process within the EBID MFM are theoretically simulated and discussed for improved isolation yield with a high degree of quality and purity.

Photoplethysmography (PPG) sensors are widely used to measure a variety of physiological parameters, from heart rate to clinically important peripheral oxygen saturation (SpO₂). The ease of obtaining a PPG signal simply by placing the sensor on a body site with even remotely sufficient vasculature (typically the wrist, finger, earlobe, or temple) can easily lead to overlooking the aspect of appropriate sensor contact pressure (P_c). We sought to investigate the effects of P_c from the perspective of: (i) SpO₂, (ii) pulse arrival time (PAT), and (iii) PPG features. Consequently, we developed a finger cuff device to measure multispectral (green, red, and infrared (IR)) PPG signals at different P_c levels. The SpO₂ values were found to increase, driven by the IR component, above the theoretical maximum of 100% slightly after the level of the mean arterial pressure. The maximum variation due to P_c was approximately 1.9 percentage points. PAT values calculated using the waveform feet of the red and IR channels were the most robust. PPG features were also sensitive to varying sensor P_c levels, with each feature showing a rather unique response. However, in general, a P_c between 20–30 mmHg (a slight P_c) and the level of diastolic blood pressure is likely to produce the best results on the features. Overall, the results showed that sensor P_c is a source of inaccuracy in PPG analysis and therefore should be given more consideration in device designs.

Glioblastoma multiform (GBM), the most occurring brain tumor comprises radiation therapy, chemotherapy, and surgery as its treatment modalities. A significant hurdle is the insufficient or impeded transport of drugs to the central nervous system (CNS), linked to the protective influence of the blood-brain barrier (BBB). Nanotechnology can help to deliver therapeutic drugs into the central nervous system (CNS) by crossing the BBB. Paclitaxel (PTX) is a broad-spectrum anticancer compound that possesses scientifically proven anticancer activity. Despite having limited applications due to partial solubility and toxicity due to cosolvent preparation, it has shown encouraging outcomes in the treatment of GBM. In these cases, nanotechnology and nanoparticles added certain advantages such as increasing drug half-life, lowering toxicity, and enhancing the permeability and retention across BBB in tumor targeting. This review article is aimed at summarizing the current state of research works on nanotechnology and nanoparticles (NPs) containing PTX in the treatment of Glioblastoma.

Hemodialysis therapy is a crucial life-saving treatment for severe kidney conditions, particularly in cases where organ transplantation is limited. However, the use of polymeric membranes in clinical dialyzers can trigger undesirable reactions in the blood, such as complement, leukocyte, and coagulation activations. These reactions can lead to hypertension, cardiovascular diseases, and even death, due to compatibility issues. This paper presents a study on the development and application of a novel phosphobetaine zwitterion, immobilized on polyethersulphone (PES) clinical hemodialysis membranes, to improve hemocompatibility. The study also introduces a new method for immobilizing a zwitterionic PVP-phosphobetaine polymer on a PES membrane, using a polydopamine (PDA) crosslinker. The synthesized membranes were characterized, and their performance in terms of blood-protein adsorption and subsequent interaction, specifically with fibrinogen, was investigated to evaluate hemocompatibility. The selection of the phosphobetaine polymer was driven by its capacity to form an electrically neutral zwitterionic hydration layer, which serves as a protective barrier, preventing fibrinogen adsorption. Without this zwitterionic polymer, blood proteins interact with the bare membrane, initiating biological processes that lead to inflammation when exposed to uremic blood. Molecular docking studies were conducted to understand the interactions between various ligands and specific serum protein components. The phosphate and carbonyl chemical groups on the pyrrolidinone zwitterionic moiety were found to form polar interactions with specific amino acids. Exvivo investigations involving incubated coated membranes and uremic blood samples from end-stage renal disease (ESRD) patients revealed that they caused weaker complement and coagulation activation compared to bare PES membranes. In addition, the inflammatory biomarkers have been studied to shed light on their potential impact on patients' quality of life. This study contributes to our understanding of the implications of blood-protein fouling and the hemocompatibility challenges faced by blood-contacting devices used in hemodialysis for ESRD patients, who are prone to membrane-related health complications.

Stroke has become a leading cause of disability worldwide. Early medication and rehabilitation is the key to help post-stroke survivors recover faster. Presently, doctors rely on imaging modalities like CT/MRI for diagnosing stroke patients. The diagnosis done using these modalities can be highly subjective. Apart from this, these imaging modalities are very costly, time taking and inconvenient for the patients. So there is a need of faster, portable and an automated diagnostic system for assessing post-stroke conditions so that right measures can be taken in the right time. To cater to this need EEG comes in handy because of its portable nature. So, in this work, utility of EEG has been studied to diagnose three aspects of stroke: 1) type of stoke, 2) affected artery and 3) severity of stroke. To achieve this, one-minute resting state EEG data was used to extract 57 features. The features were ranked and selected using ranking algorithm and deep learning (DL) models were trained with supervision from information extracted using MRI data. To find out type of stroke and affected artery DWI, SWI and MRA images were used, and severity of stroke was recorded in terms of NIHSS score. Three different DL models were trained for each task i.e. type of stroke, affected artery and severity of stroke. For classifying type of stroke an accuracy of 97.74% was obtained using 37 features. For stroke severity, the model gave RMSE of 2.1955 with a high correlation value (r = 0.91). The DL model for classifying affected artery used 33 features and gave accuracy of 95.7%. It was also found that less complex time domain features and QEEG features were frequently selected out of 57 features for all the DL models. Features in delta and theta sub-bands were frequently selected along with QEEG features. The work presented here established that EEG can act as a reliable modality for faster diagnosis of stroke specifics and hence can help medical professionals in speeding the decision making process.