Biomedical Engineering

A close interplay with institutional partners (hospitals, medical clinics and clinical institutes) and high-tech instrumentation companies, strongly accounts for a close assessment of requirements in this field with a permanent follow up of physicians and other clinical professionals. The strengthen of already established protocols with these institutions, such as the Central Hospital of Coimbra (CHUC), Garcia da Horta Hospital (HGH), the Cardiovascular Research and Formation Institute (IIFC) and the College of Health Technology of Coimbra (ESTeSC) and Faculty of Medical Sciences (FCM), grants access to both professionals and patients in hemodynamics fields, and accounts for a strong, and growingly fruitful, interplay. The main purpose of this research line is the development of innovative instrumentation (including sensors, data acquisition systems and analysis methodologies) for a better understanding and characterization of individual patients and populations related to cardiovascular disease (CVD) pathologies.

Laser imaging studies aim to propose new instrumentation and methodology solutions for point and surface cutaneous blood perfusion measurement. The use of Doppler and laser speckle imaging techniques is the technical ground base for the developments in this field, with activities performed in collaboration with ESAIP (ÉcoleSupérieurAngevined’Informatique et de Productique – Angers, France). The microvascular blood flow (perfusion) monitoring using these laser imaging techniques is a very useful procedure to evaluate and understand the mechanisms underlying the blood delivery functions in the capillary bed of the skin tissue. Several methods have been proposed for monitoring this microvascular blood flow and provide insight to dysfunction symptomatologies. The knowledge of the sampling depth of the perfusion assessment is important as the interest of clinicians dealing with microcirculation is strongly focused on the discrimination of information in the perfusion signal from superficial (nutritive) and deeper (thermoregulatory) layers of the tissue. An efficient technique that reliably differentiates between nutritive and thermoregulatory blood flow could potentially reveal valuable diagnostic information and increase our understanding about many common medical conditions such as diabetes, peripheral vascular diseases and Raynaud’s phenomenon.

Medical Imaging is also a strong area of activity, namely MR Imaging – MR Phase Contrast flow, BOLD, Diffusion Tensor, T", volumetry, T2, fMRI and EEG/fMRI – applied to: the muscle to model fatigue, to quantify the flow of Cerebrospinal fluid in the brain, to assess Alzheimer’s disease and find the foci of the epileptic brain. At the level of optical radiation, studies have included light propagation in biological tissues: applications in ophthalmology and phototherapy, and simulation of the human eye with the view of developing new diagnose methodologies. Electrophysiological signal processing is related with the extraction and computation of relevant information from a large set of biosignal sources via advanced signal processing techniques. The biosignals under the focus of research, with the needed intruments to collect are EEG, EMG, ECG, BVP, respiration, pupillometry, Human joints angles, accelerometry, pressure, among others. The information extraction is based on a set of techniques as listed: localization of neuronal sources by dipolar approaches and minimum norm estimations (in EEG), denoising methods as principal Component Analysis, PCA, and Independent Component Analysis, ICA, classification of data by Independent Component Analysis, ICA, and Wavelet techniques, Evaluation of the brain connectivity by Reference Phase Analysis, RPA); Parallel processing of biosignals; Pattern recognition for sports performance evaluation; Data mining on human movement applied to Ambient Assisted Living; Visualization of long term biosignals; Miniaturized sensor development for electrophysiology.

Instrumentation, namely related to rehabilitation and well being, has been developed (SYPEC - System for Postural Evaluation and Correction; Device to measure spasticity; Corrective Toys) Analytical Techniques in Biomedicine include Nuclear Techniques as 41Ca and 129I AMS for bone disease and cancer studies; Atomic Techniques as X-ray fluorescence, XRF, and Electrothermal Atomic Absorption Spectrometry, ETAAS, for elemental concentration in biological tissues (toxicity studies) and Ion Mobility Spectrometry - breath analysis, quality control of biological matrices and medical devices.

These capabilities enables the creation of collaboration for the development of clinical applications, where we list the major national collaborations: Faculdade de Ciências Médicas, Faculdade de Motricidade Humana, Hospital Garcia d’Orta, Hospitais Centrais de Lisboa, Instituto de Medicina Molecular, Clínica de Ressonância Magnética de Caselas, Maternidade Alfredo da Costa, Clínica Oncológica Natália Chaves, Instituto Português de Oncologia, Instituto Champalimaud, IPATIMUP - Institute of Molecular Pathology and Immunology at the University of Porto.

Development of innovative instrumentation in the scope of the biomedical engineering including sensors, electronics interface modules, front-end data acquisition platforms and architectures, for the areas of hemodynamics condition assessment (both macrocirculation and microcirculation), bioimpedance spectroscopy and tomography living tissue applications and human-machine interface (real time eye and gaze tracking platforms);

• Development of original processing methodologies (algorithms and techniques) for data analysis of the developed instrumentation modules and third-party instrumentation elements in all the research lines of biomedical engineering. Complementary, the use, and adaptation, of methods from other research fields should be promoted, since several successful examples in the past account for the benefits of this approach.
• Promotion of new large scale data mining and analysis techniques for the fine characterization of clinical populations, identification of clusters and classes with clinical relevance, improvement of diagnostics support tools and enhancement of existing methods.
• Proposal of clinical protocols (newly designed for the use of the developed systems or based on existing ones), to improve the access and understanding of the clinical professionals to the data granted by currently used and developed platforms.
• Development and application of analytical methods to the study of diseases
• Medical imaging for neurological disorders and biomechanics studies.

Under the scope of the scientific production hereby described the main goals is the production of scientific paper for publication on peer reviewed journals of reference in the field, along with the regular participation in conferences and meetings.

All the above listed items account for a broader strategic objective of turning the proposed unit into an international research group of reference in data acquisition and control systems and in electronics for biomedical instrumentation. With this in mind, a list of additional objectives will be pursuit with relevance for:

• The promotion of long term international collaborations with research units with a similar mission in the listed research fields;
• The active participation in international consortia for application of international competitive funding calls (in the scope of European research funding programs such as H2020 or others)
• The promotion of new start-up companies with activities in the scope of the research lines.
• The formation of highly specialized human resources in the biomedical engineering area (both MSc and PhD) that support the research activities and the collaborations.
• The support and initiative in the organization of international meetings (technical and/or scientific) with the peers. During the period referred in this application (2015-2020) this research Unit aims at the achievement of the status of reference center with regular participation of its members on evaluation panels and consultant expert panels for national and international funding agencies.

Biosignal Processing

• After participating in the development of a variety of algorithmic tools in the framework of complex systems, suitable for source separation rooted on synchrony phenomena, we have now started to test them in the context of cortico-muscle control, in very specific hand movement tasks.
• Study of the autonomic nervous system through, e.g., heart rate variability, pupillometry and electrodermal activity. Targeted applications include studies in cardiovascular diseases and diabetes.
• Evaluation of the effects of mindfulness meditation in stress, through the analysis of electrophysiological signals, such as, EEG, ECG and EDA.
• Integration of hemodynamics probes with other biomedical relevant measurements in assisted clinical protocols (e.g. otorhinolaryngology, physiotherapy and cardiopulmonary resuscitation).
• Instrumentation for rapid diagnostics test (RDTs) of malaria in collaboration with the companies Matibabu and Resilient African Network.

Dental Implants

• We demonstrated for the first time, with Raman spectroscopic methods, that oxygen is entrapped in dental enamel after bleaching. Further studies will be carry on since it has a significant clinical and economic impact, as dental bleaching interferes with dental adhesives, possibly due to oxygen.
• Our studies have suggested that recent class of these products, which are fluoride rich, may decrease dental erosion and be safer. We intend to foster industry partnership and contracts to continue this study.

Biomechanics

• The Vertebral Metrics, a non-invasive and ionizing radiation free solution that measures the 3D position of the vertex of the spinal process, has been clinically validate. It is currently in its clinical trial phase with the collaboration of the Sensing Future company.
• VR4NeuroPain is an innovative system that allows the collection and analysis of various physiological parameters, gathered considerable attention during Web Summit 2017.

Medical Image Analysis

• It will be applied a new machine learning method for tissue segmentation of structural magnetic resonance image (MRI) data to study tissues resulting from neurodegenerative diseases, like some tumors, in the context of characterizing patients with Down Syndrome and Alzheimer.

Medical Image Analysis

• In addition, a significant contribution made by LIBPhys’ research is to bring outcomes of Biomedical Engineering basic and applied research to solving specific questions posed by the clinic community. The rather diverse and often small projects, target as well the elderly, as the young person; healthy, or with some type of pathology.
  • RehabVisual: a new platform to stimulate children with cognitive and perceptive deficits;
  • Happy: technical toys (adaption of ludic devices to specific needs of children, and their deficit);
  • new types of multi-valence prosthetics, capable of solving particular motoric deficiencies.