[First Experience with Diaphragm Pacing System in the Czech Republic]

Patients with impaired diaphragm function are dependent on long-term mechanical ventilation. It is associated with numerous health complications as well as significant economic burden. Intramuscular diaphragm stimulation through laparoscopic implantation of pacing electrodes is a safe method which enables restoring breathing using diaphragm in a considerable number of patients. The first implantation of diaphragm pacing system in the Czech Republic was performed in a thirty-four-year-old patient suffering from a high-level cervical spinal cord lesion. After eight years of mechanical ventilation support, just five months from initiation of stimulation, the patient is able to breathe spontaneously for ten hours per day on average, with expected total weaning. Once the insurance companies decide to reimburse the pacing system, a widespread use of the method even in patients with other diagnoses, including children, is expected. Key words: electrical stimulation, diaphragm, spinal cord injury, laparoscopic surgery.

Finding Eden - alternative transplantation sites for pancreatic islets

Pancreatic islets transplantation is an established treatment method for type 1 diabetic patients with the hypoglycemia unawareness syndrome in whom a therapy with modern technologies fails. Islet transplantation is most commonly done using an interventional radiology method: a tissue suspension of pancreatic islets is applied into a branch of the portal vein through a percutaneously installed catheter. Although being minimally invasive unlike pancreas organ transplant, this method is associated with many technical difficulties. Possible complications of the procedure include hemorrhage and portal vein thrombosis. Unlike their natural dispersed localization in exocrine pancreas, isolated pancreatic islets are exposed to hypoxia, toxins and immunosuppressive drugs in the liver parenchyma. Direct contact with the recipients blood causes an instant blood mediated inflammatory reaction (IBMIR) resulting in the death of more than half of the pancreatic islets shortly after their application. Therefore the size of the islet graft is often insufficient and a number of transplanted patients require administration of exogenous insulin. All of these are reasons for seeking an alternative transplantation site with more hospitable conditions for long-term islet survival. Various transplantation sites have been tested in experimental and clinical research. The advantages and disadvantages of some of them are summarized in this paper. Currently, transplantation into the greater omentum seems most promising, which has already been used in clinical practice at several institutions.

Bioluminescence Imaging In Vivo Confirms the Viability of Pancreatic Islets Transplanted into the Greater Omentum

PURPOSE

The liver is the most widely used site for pancreatic islet transplantation. However, several site-specific limitations impair functional success, with instant blood-mediated inflammatory reaction being the most important. The aim of this study was to develop a preclinical model for placement of the islet graft into a highly vascularized omental flap using a fibrin gel. For this purpose, we tested islet viability by bioluminescence imaging (BLI).

PROCEDURES

Pancreatic islets were isolated from luciferase-positive and luciferase-negative rats, mixed at a 1:1 ratio, placed into a plasma-thrombin bioscaffold, and transplanted in standard (10 pancreatic islets/g wt; n = 10) and marginal (4 pancreatic islets/g wt; n = 7) numbers into the omentums of syngeneic diabetic animals. For the control, 4 pancreatic islets/g were transplanted into the liver using the standard procedure (n = 7). Graft viability was tested by bioluminescence at days 14, 30, 60, and 90 post transplant. Glucose levels, intravenous glucose tolerance, and serum C-peptide were assessed regularly.

RESULTS

Nonfasting glucose levels < 10 mmol/l were restored in all animals. While islet viability in the omentum was clearly detected by stable luminescence signals throughout the whole study period, no signals were detected from islets transplanted into the liver. The bioluminescence signals were highly correlated with stimulated C-peptide levels detected at 80 days post transplant. Glucose tolerance did not differ among the 3 groups.

CONCLUSIONS

We successfully tested a preclinical model of islet transplantation into the greater omentum using a biocompatible scaffold made from autologous plasma and human thrombin. Both standard and marginal pancreatic islet numbers in a gel-form bioscaffold placed in the omentum restored glucose homeostasis in recipients with diabetes. Bioluminescence was shown promising as a direct proof of islet viability.

The efficiency of insulin production and its content in insulin-expressing model β-cells correlate with their Zn2+ levels

Insulin is produced and stored inside the pancreatic β-cell secretory granules, where it is assumed to form Zn2+-stabilized oligomers. However, the actual storage forms of this hormone and the impact of zinc ions on insulin production in vivo are not known. Our initial X-ray fluorescence experiment on granules from native Langerhans islets and insulinoma-derived INS-1E cells revealed a considerable difference in the zinc content. This led our further investigation to evaluate the impact of the intra-granular Zn2+ levels on the production and storage of insulin in different model β-cells. Here, we systematically compared zinc and insulin contents in the permanent INS-1E and BRIN-BD11 β-cells and in the native rat pancreatic islets by flow cytometry, confocal microscopy, immunoblotting, specific messenger RNA (mRNA) and total insulin analysis. These studies revealed an impaired insulin production in the permanent β-cell lines with the diminished intracellular zinc content. The drop in insulin and Zn2+ levels was paralleled by a lower expression of ZnT8 zinc transporter mRNA and hampered proinsulin processing/folding in both permanent cell lines. To summarize, we showed that the disruption of zinc homeostasis in the model β-cells correlated with their impaired insulin and ZnT8 production. This indicates a need for in-depth fundamental research about the role of zinc in insulin production and storage.

[Hemicorporectomy as the Highest Grade of En Bloc Sacrectomy]

Hemicorporectomy or translumbar amputation is an extensive surgical procedure consisting in removing the lower portion of the body. Thakur et al. found a total of 71 hemicorporectomies described in literature before 2017. In the form of a case study we present the case of our patient with terminal pelvic osteomyelitis, in whom hemicorporectomy was subsequently performed, namely from the spine surgery perspective. The man, 19 years old, was exposed to high-voltage electricity and fell down from a height of 4 meters. He suffered an instable comminuted fracture of T10 (AO A3.3.) with paraplegia (Frankel A) and multiple third-degree burns affecting 25% of his total body surface area. Subsequently, the patient underwent a total of 16 surgical procedures performed by medical experts in various specialties (orthopaedic surgery, general surgery, plastic surgery, urology, vascular surgery), but in spite of that the extensive pelvic osteomyelitis has not been successfully managed. At first, urine and stool diversion were performed. After 3 weeks, i.e. 18 months after the injury, the removal of the lower portion of the body was scheduled. The hemicorporectomy was divided into 4 stages. The surgery started by posterior transecting the spine at L4-L5 segment with nerve root and dural sac ligation and treating the bleeding venous plexus in the spinal canal. After turning the patient to the supine position, the second stage of the operation followed, consisting in transecting large vessels and harvesting a musculocutaneous flap from the right thigh. During the third stage of the surgery the separation of the L4-L5 motion segment was completed by the transaction of the anterior longitudinal ligament and m. psoas major, subsequently followed by the amputation of the lower portion of the body. During the last stage of the surgery, the wound was closed by musculocutaneous flap from the fight thigh with preserved a. femoralis. The patient was discharged to home in a generally good condition 127 days after the amputation of the lower portion of the body. Now, 1 year after the surgery, the patient enjoys good physical as well as mental health. Hemicorporectomy is an extensive surgical technique, which can despite multiple complications be offered to patients with otherwise unmanageable condition. Terminal pelvic osteomyelitis is currently the most frequent diagnostic indication and the resulting condition makes possible a long-term survival of the patient in a satisfactory condition. The spinal surgeon is an irreplaceable member of the multidisciplinary team performing the surgical procedure, the primary treatment of the spinal column considerably limits blood losses. Key words: hemicorporectomy, en bloc sacrectomy, terminal pelvic osteomyelitis, sacral tumors.

A Trimodal Imaging Platform for Tracking Viable Transplanted Pancreatic Islets In Vivo: F-19 MR, Fluorescence, and Bioluminescence Imaging

PURPOSE

Combining specific and quantitative F-19 magnetic resonance imaging (MRI) with sensitive and convenient optical imaging provides complementary information about the distribution and viability of transplanted pancreatic islet grafts. In this study, pancreatic islets (PIs) were labeled with positively charged multimodal nanoparticles based on poly(lactic-co-glycolic acid) (PLGA-NPs) with encapsulated perfluoro-15-crown-5-ether and the near-infrared fluorescent dye indocyanine green.

PROCEDURES

One thousand and three thousand bioluminescent PIs were transplanted into subcutaneous artificial scaffolds, which served as an alternative transplant site. The grafts were monitored using in vivo F-19 MR, fluorescence, and bioluminescence imaging in healthy rats for 2 weeks.

RESULTS

Transplanted PIs were unambiguously localized in the scaffolds by F-19 MRI throughout the whole experiment. Fluorescence was detected in the first 4 days after transplantation only. Importantly, in vivo bioluminescence correlated with the F-19 MRI signal.

CONCLUSIONS

We developed a trimodal imaging platform for in vivo examination of transplanted PIs. Fluorescence imaging revealed instability of the fluorescent dye and its limited applicability for longitudinal in vivo studies. A correlation between the bioluminescence signal and the F-19 MRI signal indicated the fast clearance of PLGA-NPs from the transplantation site after cell death, which addresses a major issue with intracellular imaging labels. Therefore, the proposed PLGA-NP platform is reliable for reflecting the status of transplanted PIs in vivo.

Vibrational Structure in Magnetic Circular Dichroism Spectra of Polycyclic Aromatic Hydrocarbons

Absorption and magnetic circular dichroism (MCD) spectroscopies are powerful and simple methods to discriminate among various compounds. Polycyclic aromatic hydrocarbons provide particularly strong signal, which, for example, facilitates their detection in the environment. However, interpretation of the spectra is often based on quantum-chemical simulations, providing a limited precision only. In the present work, we use time-dependent density functional theory and complete active space second-order perturbation theories to understand spectral features observed in a series of naphthalene, anthracene, phenanthrene, and three larger compounds. The electronic computations provided reasonable agreement with the experiment for the smaller molecules, while a large error persisted for the bigger ones. However, many discrepancies could be explained by vibrational splitting of the electronic transitions across the entire spectral range. Compared to plain absorption, MCD spectral bands and their vibrational splitting were more specific for each aromatic molecule. The computational tools allowing simulations of detailed vibrational features in the electronic spectra thus promise to open a qualitatively new chapter in the spectroscopy of aromatic compounds.

Multimodal Imaging Reveals Improvement of Blood Supply to an Artificial Cell Transplant Site Induced by Bioluminescent Mesenchymal Stem Cells

PURPOSE

An artificial site for cell or pancreatic islet transplantation can be created using a polymeric scaffold, even though it suffers subcutaneously from improper vascularisation. A sufficient blood supply is crucial for graft survival and function and can be enhanced by transplantation of mesenchymal stem cells (MSCs). The purpose of this study was to assess the effect of syngeneic MSCs on neoangiogenesis and cell engraftment in an artificial site by multimodal imaging.

PROCEDURES

MSCs expressing a gene for luciferase were injected into the artificial subcutaneous site 7 days after scaffold implantation. MRI experiments (anatomical and dynamic contrast-enhanced images) were performed on a 4.7-T scanner using gradient echo sequences. Bioluminescent images were acquired on an IVIS Lumina optical imager. Longitudinal examination was performed for 2 months, and one animal was monitored for 16 months.

RESULTS

We confirmed the long-term presence (lasting more than 16 months) of viable donor cells inside the scaffolds using bioluminescence imaging with an optical signal peak appearing on day 3 after MSC implantation. When compared to controls, the tissue perfusion and vessel permeability in the scaffolds were significantly improved at the site with MSCs with a maximal peak on day 9 after MSC transplantation.

CONCLUSIONS

Our data suggest that the maximal signal obtained by bioluminescence and magnetic resonance imaging from an artificially created site between 3 and 9 days after MSC transplantation can predict the optimal time range for subsequent cellular or tissue transplantation, including pancreatic islets.

On the magnetic circular dichroism of benzene. A density-functional study

Spectroscopy of magnetic circular dichroism (MCD) provides enhanced information on molecular structure and a more reliable assignment of spectral bands than absorption alone. Theoretical modeling can significantly enhance the information obtained from experimental spectra. In the present study, the time dependent density functional theory is employed to model the lowest-energy benzene transitions, in particular to investigate the role of the Rydberg states and vibrational interference in spectral intensities. The effect of solvent is explored on model benzene-methane clusters. For the lowest-energy excitation, the vibrational sub-structure of absorption and MCD spectra is modeled within the harmonic approximation, providing a very good agreement with the experiment. The simulations demonstrate that the Rydberg states have a much stronger effect on the MCD intensities than on the absorption, and a very diffuse basis set must be used to obtain reliable results. The modeling also indicates that the Rydberg-like states and associated transitions may persist in solutions. Continuum-like solvent models are thus not suitable for their modeling; solvent-solute clusters appear to be more appropriate, providing they are large enough.

Innovative Educational Program for Biogas Production Carried Out at University of Hradec Králové (CZ) and at University of Opole (PL)

Recently, there is a growing pressure on a rapid construction of agricultural biogas plants, particularly in the Czech-Polish border region. It is an area with large expanses of agricultural land which can serve to supply biogas plants with biomass. This strategy should contribute to harmonize the common agricultural policy of the European Union. A need for qualified operators of these stations on this territory is also increasing. Therefore we first include a demonstration of an education program for students in the field of agricultural waste anaerobic fermentation and biogas production. We present here the first part of an innovative approach which we use in the teaching program “Physico-technical Measurements and Computer Technology” at the Faculty of Science at the University of Hradec Kralove and also in the education of internshipers from the Faculty of Natural Sciences and Technology at the University of Opole. There are requirements to fulfil labour market expectations and to make this subject more attractive for the students. Students’ theoretical and practical preparation constitutes a comprehensive source of knowledge and skills required in a real life job. Joined theoretical and practical knowledge gained by students, reinforced by the skills developed during task analysis followed by their solution, provides the future graduate higher quality abilities and better position in the labour market.

Automated Analysis of Microscopic Images of Isolated Pancreatic Islets

Clinical islet transplantation programs rely on the capacities of individual centers to quantify isolated islets. Current computer-assisted methods require input from human operators. Here we describe two machine learning algorithms for islet quantification: the trainable islet algorithm (TIA) and the nontrainable purity algorithm (NPA). These algorithms automatically segment pancreatic islets and exocrine tissue on microscopic images in order to count individual islets and calculate islet volume and purity. References for islet counts and volumes were generated by the fully manual segmentation (FMS) method, which was validated against the internal DNA standard. References for islet purity were generated via the expert visual assessment (EVA) method, which was validated against the FMS method. The TIA is intended to automatically evaluate micrographs of isolated islets from future donors after being trained on micrographs from a limited number of past donors. Its training ability was first evaluated on 46 images from four donors. The pixel-to-pixel comparison, binary statistics, and islet DNA concentration indicated that the TIA was successfully trained, regardless of the color differences of the original images. Next, the TIA trained on the four donors was validated on an additional 36 images from nine independent donors. The TIA was fast (67 s/image), correlated very well with the FMS method (R2=1.00 and 0.92 for islet volume and islet count, respectively), and had small REs (0.06 and 0.07 for islet volume and islet count, respectively). Validation of the NPA against the EVA method using 70 images from 12 donors revealed that the NPA had a reasonable speed (69 s/image), had an acceptable RE (0.14), and correlated well with the EVA method (R2=0.88). Our results demonstrate that a fully automated analysis of clinical-grade micrographs of isolated pancreatic islets is feasible. The algorithms described herein will be freely available as a Fiji platform plugin.

Unstable Expression of Commonly Used Reference Genes in Rat Pancreatic Islets Early after Isolation Affects Results of Gene Expression Studies

The use of RT-qPCR provides a powerful tool for gene expression studies; however, the proper interpretation of the obtained data is crucially dependent on accurate normalization based on stable reference genes. Recently, strong evidence has been shown indicating that the expression of many commonly used reference genes may vary significantly due to diverse experimental conditions. The isolation of pancreatic islets is a complicated procedure which creates severe mechanical and metabolic stress leading possibly to cellular damage and alteration of gene expression. Despite of this, freshly isolated islets frequently serve as a control in various gene expression and intervention studies. The aim of our study was to determine expression of 16 candidate reference genes and one gene of interest (F3) in isolated rat pancreatic islets during short-term cultivation in order to find a suitable endogenous control for gene expression studies. We compared the expression stability of the most commonly used reference genes and evaluated the reliability of relative and absolute quantification using RT-qPCR during 0–120 hrs after isolation. In freshly isolated islets, the expression of all tested genes was markedly depressed and it increased several times throughout the first 48 hrs of cultivation. We observed significant variability among samples at 0 and 24 hrs but substantial stabilization from 48 hrs onwards. During the first 48 hrs, relative quantification failed to reflect the real changes in respective mRNA concentrations while in the interval 48–120 hrs, the relative expression generally paralleled the results determined by absolute quantification. Thus, our data call into question the suitability of relative quantification for gene expression analysis in pancreatic islets during the first 48 hrs of cultivation, as the results may be significantly affected by unstable expression of reference genes. However, this method could provide reliable information from 48 hrs onwards.

Modelling of Emissions from Large Biogas Plants

The main objective of the “Guidelines for the development of agricultural biogas plants in Poland within 2010-2020”, is a construction of biogas plants processing agricultural biomass resources with suitable conditions in each municipality. In the Czech Republic produces about 6.5% of energy from renewable sources. Biogas plants give - contrary to solar and wind electricity stations - the stable performance throughout the whole year. Biomass should be a key source for achieving the Czech EU commitment to produce 13% of energy from renewable sources in 2020. The experience, where 317 Agricultural biogas plants are currently in operation, has shown that there are considerable problems with a proper location of newly designed agricultural biogas plants in the landscape. The Czech-Polish border area is mainly flat wooded recreation region. For these reasons, the Gaussian model SYMOS’97 (version 2013), adapted for odour dispersion modelling from large agricultural sources is supposed to be suitable for this area. It is appropriate for training of students. For these reasons, students from the University of Hradec Kralove and the University of Opole in the frame of their academic exchange and professional internships are acquainted with the technological principles of biogas plants and in environmental mathematical and statistical modelling of the spread of emissions from large industrial and agricultural sources. In this article we present methods for education on these professional areas.

[Islet transplantation as a treatment for hypoglycemia unawareness syndrome. Evaluation of the pilot program and comparison with pancreas transplantation]

Islet transplantation (ITx) started in 2005 in IKEM as a potentially safer alternative to pancreas transplantation (PTx), which so far had represented the method of choice in type-1 diabetic patients with conservatively intractable hypoglycemia unawareness syndrome. The aim of the study was to compare these two methods with regard to severe hypoglycemia elimination and to frequency of complications.Up to November 2015 a total number of 48 patients underwent ITx. The results from 22 patients with hypoglycemia unawareness were statistically analyzed. The mean number of transplanted islet equivalents was 12,096 (6,93316,705) IEQ/kg administered percutaneously in local anesthesia under radiological control to the portal vein. 44 patients underwent PTx from 1996. We evaluated glycated hemoglobin(HbA1c), insulin dose, fasting and stimulated C-peptide, frequency of severe hypoglycemia and complications. Medians (interquartile range) were analyzed using the Wilcoxon signed-rank test.One and two years after ITx, HbA1c decreased, C-peptide became significantly positive, insulin dose and frequency of severe hypoglycemia decreased and 18 % of ITx recipients were temporarily insulin-independent. Bleeding was present in 41 % of patients. One year after PTx, 73 % of patients were insulin and hypoglycemia-free, after two years 68 % of patients were insulin and hypoglycemia-free; graftectomy occurred in 20 % of recipients.Both methods led to restoration of insulin secretion and severe hypoglycemia elimination. PTx made more recipients insulin-independent at the cost of serious complications.

[Destruction of the Humeral Head in Sensory Deficit due to the Spinal Hemorhagia. Case Report]

Degenerative changes of the shoulder are a common complication in patients after spinal cord injury. The main cause is chronic overload to the shoulder joint due to manual wheelchair propulsion and transfers. Reduced shoulder function has a significant impact on all aspects of daily life. Shoulder arthroplasty in this group of patients is a challenging procedure because of the unique demand on the shoulder. This report presents the case of a wheelchair user who additionally experienced a complete loss of sensation around her shoulder. As a result of a repetitive strain during transfers from the wheelchair to the ground, the humeral head was destroyed.

Innovation in Study of Physical and Technical Measurements. Czech-Polish Cooperation of Universities / Innowacje Studiów Fizyczne I Techniczne Metody Pomiarowe. Czesko-Polska Współpraca Uniwersytetów

In the Faculty of Science (University of Hradec Králové) the innovative program in chemistry for the study specialization Physico-technical Measurements and Computer Technology was developed. The innovation of chemistry filed study has been focused especially on increase in competitiveness and in graduates employment. Design of innovation enables graduates applying for the position of experts in physical measurements and informatics and at the same time they expand their competence in the service of the physico-chemical instrumentation in industrial ecology. Because Faculty of Science is not equipped yet in expensive instrumentation for nuclear spectrometry, cross-border cooperation with the Faculty of Natural and Technical Sciences (University of Opole) has been started. In the area of teaching about non-traditional energy sources the cross-border cooperation with the Department of Automation and Renewable Energy Sources, Faculty of Electrical Engineering (Czestochowa University of Technology) has been initiated. Well-developed system of cooperation with companies, which are equipped with the latest technology of environmental protection, was created. In the exchange system Polish students attended for practicing in these companies. The aim of the contribution is to describe one of the means of innovation of chemistry field study in the frame of bachelor study specialization oriented in physics and computer technology. We believe that the new approach will lead to increase in graduate competitiveness as well as to development of their motivation to study and better understanding of regulation principles of chemical processes and patterns.

Dip TIPS as a facile and versatile method for fabrication of polymer foams with controlled shape, size and pore architecture for bioengineering applications

The porous polymer foams act as a template for neotissuegenesis in tissue engineering, and, as a reservoir for cell transplants such as pancreatic islets while simultaneously providing a functional interface with the host body. The fabrication of foams with the controlled shape, size and pore structure is of prime importance in various bioengineering applications. To this end, here we demonstrate a thermally induced phase separation (TIPS) based facile process for the fabrication of polymer foams with a controlled architecture. The setup comprises of a metallic template bar (T), a metallic conducting block (C) and a non-metallic reservoir tube (R), connected in sequence T-C-R. The process hereinafter termed as Dip TIPS, involves the dipping of the T-bar into a polymer solution, followed by filling of the R-tube with a freezing mixture to induce the phase separation of a polymer solution in the immediate vicinity of T-bar; Subsequent free-drying or freeze-extraction steps produced the polymer foams. An easy exchange of the T-bar of a spherical or rectangular shape allowed the fabrication of tubular, open- capsular and flat-sheet shaped foams. A mere change in the quenching time produced the foams with a thickness ranging from hundreds of microns to several millimeters. And, the pore size was conveniently controlled by varying either the polymer concentration or the quenching temperature. Subsequent in vivo studies in brown Norway rats for 4-weeks demonstrated the guided cell infiltration and homogenous cell distribution through the polymer matrix, without any fibrous capsule and necrotic core. In conclusion, the results show the "Dip TIPS" as a facile and adaptable process for the fabrication of anisotropic channeled porous polymer foams of various shapes and sizes for potential applications in tissue engineering, cell transplantation and other related fields.

Activation of the Jak/Stat signalling pathway by leukaemia inhibitory factor stimulates trans-differentiation of human non-endocrine pancreatic cells into insulin-producing cells

Differentiation of pancreatic β-cells is regulated by a wide range of signalling pathways. The aim of our current work was to evaluate the effect of the Jak/Stat signalling pathway on the differentiation of human non-endocrine pancreatic cells into insulin-producing cells. Activation of the Jak/Stat signalling pathway by leukaemia inhibitory factor (LIF) stimulated differentiation of C-peptide-negative human non-endocrine pancreatic cells into insulin-producing cells in 6.3 ± 2.0 % cells (N = 5) and induced expression of pro-endocrine transcription factor neurogenin 3, Notch signalling pathway suppressor HES6 and stimulator of β-cell neogenesis REG3A. The expression of the REG3A gene and increased rate of differentiation into insulin-producing cells (10.2 ± 2.1 %) were further stimulated by a combination of LIF with nicotinamide and dexamethasone. Glucose-stimulated (5 vs. 20 mM) C-peptide secretion confirmed proper insulin secretory function of trans-differentiated insulin-producing cells (0.51 vs. 2.03 pmol C-peptide/μg DNA, P < 0.05). Our results indicate that Jak/Stat signalling critically contributes to trans-differentiation of non-endocrine pancreatic cells into functional insulin-producing cells. The positive effect of the Jak/Stat signalling pathway on trans-differentiation is mediated by the key genes that activate differentiation of pancreatic β-cells.

Force plate monitoring of human hemodynamics

BACKGROUND

Noninvasive recording of movements caused by the heartbeat and the blood circulation is known as ballistocardiography. Several studies have shown the capability of a force plate to detect cardiac activity in the human body. The aim of this paper is to present a new method based on differential geometry of curves to handle multivariate time series obtained by ballistocardiographic force plate measurements.

RESULTS

We show that the recoils of the body caused by cardiac motion and blood circulation provide a noninvasive method of displaying the motions of the heart muscle and the propagation of the pulse wave along the aorta and its branches. The results are compared with the data obtained invasively during a cardiac catheterization. We show that the described noninvasive method is able to determine the moment of a particular heart movement or the time when the pulse wave reaches certain morphological structure.

CONCLUSIONS

Monitoring of heart movements and pulse wave propagation may be used e.g. to estimate the aortic pulse wave velocity, which is widely accepted as an index of aortic stiffness with the application of predicting risk of heart disease in individuals. More extended analysis of the method is however needed to assess its possible clinical application.