Search results for "Biomedical engineering"
showing 10 items of 2020 documents
Principal component analysis and cluster analysis for measuring the local organisation of human atrial fibrillation
2001
The distribution of atrial electrogram types has been proposed to characterise human atrial fibrillation. The aim of this study was to provide computer procedures for evaluating the local organisation of intracardiac recordings during AF as an alternative to off-line manual classification. Principal components analysis (PCA) reduced the data set to a few representative activations, and cluster analysis (CA) measured the average dissimilarity between consecutive activations of an intracardiac signal. The data set consisted of 106 bipolar signals recorded on 11 patients during electrophysiological studies for catheter ablation. Performances of PCA and CA in distinguishing between organised (t…
CpG-Loaded Multifunctional Cationic Nanohydrogel Particles as Self-Adjuvanting Glycopeptide Antitumor Vaccines
2014
Self-adjuvanting antitumor vaccines by multifunctional cationic nanohydrogels loaded with CpG. A conjugate consisting of tumor-associated MUC1-glycopeptide B-cell epitope and tetanus toxin T-cell epitope P2 is linked to cationic nanogels. Oligonucleotide CpG complexation enhances toll-like receptor (TLR) stimulated T-cell proliferation and rapid immune activation. This co-delivery promotes induction of specific MUC1-antibodies binding to human breast tumor cells without external adjuvant.
A hyaluronic acid/cyclodextrin based injectable hydrogel for local doxorubicin delivery to solid tumors
2020
Localized delivery of anticancer drugs is often the most useful therapeutic approach for the treatment of solid tumors. The use of injectable polymeric systems that maximize drug concentration in the proximal area of the tumor represents an extremely advantageous therapeutic strategy. Here, the development of an injectable in situ forming hydrogel was accomplished by exploiting the azo-type Michael reaction between an amine derivative of hyaluronic and vinylsulfone functionalized -cyclodextrins complexing doxorubicin. This injectable system can be easily prepared and administered with timelines compatible with normal operating room procedures, as demonstrated by rheological tests. In vitro…
Motility analysis by means of video tracked markers
2018
Abstract The motility of the gastrointestinal tract is crucial for digestive activity and dysfunction can lead to severe disease pattern. A method for analysing the motility is needed when treatment approaches shall be evaluated. Therefore markers attached to different locations on the stomach and the bowel of pigs are video tracked in this research study. The markers are designed to provide a high contrast and have an adhesive side for fixation. Above the operation field a video camera has been placed to film the markers during the procedure. To analyse the video data a special algorithm has been implemented. The algorithm requires a registration process at the beginning of each recording …
Assessment of the tibia using ultrasonic guided waves in pubertal girls
2002
The purpose of this study was to compare low frequency ultrasonic guided wave measurements with established ultrasound and bone density measurements in terms of their ability to characterize the tibia in pubertal girls. Subjects were 12-14-year-old girls ( n=106) who were participating in a calcium and vitamin D intervention study. A prototype low frequency pulse transmission device consisting of a uniaxial scanning mechanism and low frequency transducers orientated perpendicularly to the limb was used to measure two ultrasound velocities in the tibia. The first velocity, V1, was that of the first arriving signal, similar to that measured by existing commercial tibial ultrasound devices. Th…
Treatment of Knee Osteoarthritis with Bone Marrow-Derived Mononuclear Cell Injection: 12-Month Follow-up.
2018
Objectives To evaluate the main symptoms of knee osteoarthritis (OA) and tissue structure changes after a single dose bone marrow–derived mononuclear cell (BM MNC) intra articular injection. Case series study. Patients with knee OA Kellgren Lawrence (K-L) grade II and III received 1 injection of BM MNC. The clinical results were analyzed with the Knee injury and Osteoarthritis Outcome Score (KOOS) and Knee Society Score (KSS) before, 3, 6, and 12 months after injection. Radiological evaluation was performed with a calibrated x-ray and the magnetic resonance (MR) imaging before and 6 to 7 months postinjection. Results A total of 34 knees were treated with BM MNC injections. Mean (±SD) age of…
Imaging of Temporomandibular Joint: Approach by Direct Volume Rendering
2014
Background: The purpose of this study was to conduct a morphological analysis of the temporomandibular joint, a highly specialized synovial joint that permits movement and function of the mandible. Materials and Methods: We have studied the temporom-andibular joint anatomy, directly on the living, from 3D images obtained by medical imaging Computed Tomography and Nuclear Magnetic Resonance acquisition, and subsequent re-engineering techniques 3D Surface Rendering and Volume Rendering. Data were analysed with the goal of being able to isolate, identify and distinguish the anatomical structures of the joint, and get the largest possible number of information utilizing software for post-proces…
In vitro comparison of the efficacy of two fractured implant-prosthesis screw extraction methods: Conventional versus mechanical.
2019
Abstract Statement of problem Implant-supported prostheses may be subject to esthetic, biological, or mechanical complications. Protocols for dealing with these mechanical problems are sparse. Purpose The purpose of this in vitro study was to compare the efficacy of a mechanical system for extracting fractured implant-prosthesis screws with the conventional method. Material and methods A total of 60 screws were divided into 2 groups according to their morphology (flat screws with a smooth shaft and threaded apical area and screws with a completely threaded body) and subjected to fatiguing and static load testing until fracture. The specimens were assigned to 3 operators with varying levels …
Bioengineered in vitro 3D model of myotonic dystrophy type 1 human skeletal muscle
2021
Abstract Myotonic dystrophy type 1 (DM1) is the most common hereditary myopathy in the adult population. The disease is characterized by progressive skeletal muscle degeneration that produces severe disability. At present, there is still no effective treatment for DM1 patients, but the breakthroughs in understanding the molecular pathogenic mechanisms in DM1 have allowed the testing of new therapeutic strategies. Animal models and in vitro two-dimensional cell cultures have been essential for these advances. However, serious concerns exist regarding how faithfully these models reproduce the biological complexity of the disease. Biofabrication tools can be applied to engineer human three-dim…
Biomechanical testing of different posterior fusion devices on lumbar spinal range of motion.
2019
Abstract Background Recent minimal-invasive posterior fusion devices are supposed to provide stability and obtain fusion in combination with interbody cages in the instrumented segment. The aim of the present study is to evaluate the primary stability of two minimal-invasive posterior prototypes compared to an established spinous process plate and standard pedicle screw instrumentation. Methods Seven fresh frozen human cadaver lumbar spines (L2–L5) were tested in a spinal testing device with a moment of 7.5 Nm. Spinal stability was determined as mean range of motion (RoM) in the segment L3/L4 during extension-flexion, lateral bending and axial rotation. The RoM was measured during five cond…