Foredrags- & Posterkonkurrence Abstracts 2015-6
Foredrags- & Posterkonkurrence Abstracts 2015-6 Art: F = Foredrag, P = Poster Art Hjemsted 1 2 3 F F F AAU AU DTU Forfatter – kun indsenderen er nævnt Mads Jochumsen Line Nørgaard Christensen Shadi Chreiteh 4 F AU Philip Weng 5 F AAU Mathias Brønd Sørensen 6 F Sundhedsinformation Sjælland m.fl. Erik S. Poulsen 7 F AU Morten Jensen 8 F AU Ida Lindhardt Jensen 9 F AU Tommy Bechsgaard 10 F AU Søren Nielsen Skov 11 F AU Michael Væggemose Magnetic resonance diffusion tensor imaging for evaluation of Diabetic Polyneuropathy 12 P AU Troels Lading In Vitro charachterization and comparison of the David and the Yacoub aortic root repair techniques with and without a supporting annular ring 13 P DTU Ali Hohebbi 14 15 P P DTU AU 16 P DTU Sissel Bisgaard Anders Esager Caspar Aleksander Bang Jespersen 17 P SDU Kathrine Holz 18 P DTU Alexander Neergaard Olesen 19 P AU Thomas Lindskow Nr. 13.09.2015/POR Titel Decoding movement intensions from single-trial EEG Individualised 3D printed brachytherapy applications Vital signs monitorering at the sternum Optimation og in vitro detection of mechanical heart valve cavitation Diagnosticering af knoglemetastaser hos patienter med prostacancer Considerations when starting a Medtech Company Development of a new heart valve porsthesis concept for pediatric cardiac surgery In Vitro investigation of pulmonary valve prosthesis constructed in CorMatrix in treatment of Tetralogy of Fallot Biomechanical description of aortic root repair procedures,preliminary Biomedical Features of a rigid remodeling Versus a fully flexible Mitral Annuloplasty Ring A brain computer interface for robust wheelchair control application Supportive algorithm for detection of REM Cell sorter for isolation of insulin producing cells Appnea: Novel Smartphone Based Application for Sleep Apnea Detection Evaluating the use of EEG for monitoring Patiens in the neurointensive care unit Nonparametric Bayesian Analysis of the Mouse Brain Connectome Assesment and comparision of stress distribution in the aortic root:after aortic root repair using Davids or Yacoubs technique SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Mads Jochumsen Fredrik Bajers Vej 7 D2-103, 9220 Aalborg Ø 40544421 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: MADS JOCHUMSEN, ASTRID C. NØRGAARD, MADS N. STAUSHOLM, REGITZE K. SKALS, SIMON C. DAHL & ERNEST N. KAMAVUAKO Department of Health Science and Technology, Aalborg University DECODING MOVEMENT INTENTIONS FROM SINGLE-TRIAL EEG Intentions to move can be seen in the EEG ~2 s prior movements; this may be exploited for reestablishing a disrupted motor control loop through braincomputer interfacing. In this work, movement intentions associated with three grasp types (pinch, palmar and lateral) were decoded from single-trial EEG. 14 healthy subjects performed the three grasps 100 times while EEG from 25 channels was recorded over the contralateral sensorimotor cortex. The continuous EEG was divided into epochs from the movement onset and 2 s prior this point and epochs containing background EEG (Fig. 1). To estimate movement detection, background EEG vs. movement intention classification was performed using linear discriminant analysis. The movement intentions were classified as well. Temporal (mean amplitudes) and spectral (power spectral densities) features were extracted from each channel. Dimensionality reduction was performed using Fisher’s discriminant projection. On average 89±5% (temporal features) of the movement intentions was correctly detected, and 56±11% (spectral features) was correctly classified according to the grasp type. Combining temporal and spectral features did not improve the performance. In conclusion, single-trial movement intentions can be decoded; this may be used for brain-computer interface applications for motor recovery or substitution. Fig. 1: Averaged brain potentials associated with different grasps. Abstrakt sendes til: [email protected] Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Line Nørgaard Christensen Adresse: Jerichausgade 15 St.Tv. Tlf. nr.: 42423634 E-mail: [email protected] SOFIE GUNHØJ MIKKELSEN, NITA VOLDER HANSEN & LINE NØRGAARD CHRISTENSEN Aarhus University School Of Engineering INDIVIDUALISED 3D PRINTED BRACHYTHERAPY APPLICATORS Worldwide, cervical cancer is the fourth most frequent cancer in women with an estimated 530.000 new cases in 2012. Brachytherapy is a treatment offered by Aarhus University Hospital, combining external radiation with internal localized radiation therapy. Fifty percent of all patients receive an intracavitary treatment with an applicator, forty percent receives a combined intracavitary/interstitial treatment with fixed needles in a tandem ring. The remaining ten percent of patients require additional free needles to be inserted. These are necessary when tumors are not positioned parallel to the applicator. The aim of this project is to enable construction of individualized brachytherapy applicators to fixate the free needles. A software program will be created to transfer geometrical information about the location of the tumor and applicator into CAD software, allowing individualized applicators to be designed and 3D printed with angled holes for the free needles. This optimization will make it possible to fix the free needles and optimize the final position relative to the target, yielding an optimal dose distribution for the individualized treatment. In addition to facilitating the technical transfer of information, the workflow and quality assurance of the treatment will be examined and optimized. Fig. 1.Cervical tumor with needles Fig. 2: Old version of racyteraphy applicator in cervix Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Shadi S. Chreiteh DTU Nanotech, Ørsteds Plads, 28158184 [email protected] Bygning 345B, 2800 Kgs. Lyngby SHADI S. CHREITEH1, BO BELHAGE2, KARSTEN HOPPE3 & ERIK V. THOMSEN1 1 Department of Micro- and Nanotechnology, DTU Bispebjerg Hospital 3 DELTA microelectronics 2 VITAL SIGNS MONITORING AT THE STERNUM For critically ill patients, it is highly important to obtain reliable measures of vital sign parameters, e.g. heart rate, respiration rate, and the oxygen saturation of the blood. The respiratory rate is assessed by manual count of the chest movements and pulse oximetry probes have previously been limited to the fingertip. These methods are documented to be time consuming or inaccurate when monitoring patients with low blood flow or decreased perfusion at the extremities (e.g. patients with COPD, diabetes, or heart failure). In this project, we have developed an optical sensor that can monitor the respiratory rate and the oxygen saturation of the blood at the sternum, cf. Fig.1. On a healthy group of subjects the respiratory rates were derived with a root mean squared error (RMSE) of 1.2 breaths /min during spontaneous respiration. As for the oxygen saturation it was derived with RMSE of 2 % during a hypoxia study. Recently, a clinical experiment conducted on 30 respiratory affected patients at Bispebjerg Hospital has showed that we were able to estimate the respiratory rate with a RMSE of 1.5 breaths/min compared to traditional capnography. The oxygen saturation was estimated with a RMSE of 2 %. These results indicates that, it is possible to design a unique device that can provide vital information about the respiration rate, the heart rate, and the oxygen saturation while reducing the limitations of traditional pulse oximetry probes. In the future, this new sensor is therefore expected to be able to provide continuous, reliable, and wireless monitoring of important vital signs in critically ill patients. Fig.1. Prototype of sternal reflectance photoplethysmographic sensor. The sensor is placed at the chest bone (sternum) using state of the art patch technology. Abstrakt sendes til: [email protected] Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Philip Weng Silkeborgvej 76 3. tv 40434069 [email protected] PHILIP WENG & PETER JOHANSEN Department of Engineering, Faculty of Science and Technology, Aarhus University, Denmark OPTIMIZATION OF IN VITRO DETECTION OF MECHANICAL HEART VALVE CAVITATION An in vitro setup, based on a mechanical heart valve single shot model was developed to investigate valve-closing sounds under non-cavitating to high cavitating conditions, in order to refine existing cavitation detection schemes. This was done, by placing the single shot model, including the pump, into a pressurized chamber. By also including the pump into the pressure chamber, cavitation was suppressed with unaltered valve closing velocity. As the pressure was increased, cavitation was gradually suppressed until completely suppressed. The occurrence of cavitation was verified through high-speed images of the valve closure. Dataset acquired at non-cavitating and highly cavitating conditions were initially used to identify and derive algorithms for detection and quantification of cavitation. Fig. 1 shows the result of the most successful method developed based on analysis of large negative pressure transients, which was identified within the valve closing sound signature during the cavitation conditions. At gauge pressures up to 0.8 bar, cavitation demonstrated a very stochastic behavior, which is illustrated by the large variance and box size. This was also expected, as the occurrence of cavitation is thought to be stochastic. At pressures above 0.8 bar, the measurements shows a linear descending pattern, representing the suppression of cavitation. Fig. 1: Boxplot of all datasets at each surrounding pressure. The dataset at fully suppressed cavitation is used as a reference to determine the grade of cavitation. SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Mathias Brønd Sørensen Borgergade 21, 3 tv. 9000 Aalborg 26399128 [email protected] Aida Hejlskov Poulsen, Kasper Kunz Leerskov, Mathias Brønd Sørensen & Rosa Hansen - Sundhedsteknologi-studerende på Aalborg Universitet Vejledere: Ole Kæseler Andersen, AAU & Thomas Bohsen Schmidt, AAUH DIAGNOSTICERING AF KNOGLEMETASTASER HOS PATIENTER MED PROSTATACANCER Prostatacancer er den hyppigste cancersygdom hos mænd med circa 4.000 tilfælde og op mod 1.200 dødsfald årligt. De fleste dødsfald er forårsaget af spredning, der hos prostatacancer patienter oftest forekommer i knoglerne. Scanning for knoglemetastaser foregår i dag med SPECT/CT-teknologi, ved en knogleskintigrafi, men nye tiltag giver anledning til revurdering af den gængse scanningsmetode. Med udgangspunkt i den tilgængelige videnskabelige litteratur og med MTVtilgang sammenlignes knogleskintigrafi og 18F-NaF PET/CT inden for fire væsentlige perspektiver i sygehusregi; teknologi, organisation, økonomi og patient. Under litteraturstudiet er det fundet, at 18F-NaF PET/CT er mere sensitiv end knogleskintigrafi både med og uden SPECT. Blandt andet på grund af en bedre spatiel opløsning, hvilket betyder, at knoglemetastaser kan detekteres tidligere med PET/CT-teknologien. Den tidligere detektering er forbundet med større livskvalitet og færre senkomplikationer for patienten. På Aalborg Universitetshospitalet udføres først en planar knogleskintigrafi, der ved tvivl-tilfælde suppleres med en SPECT/CT af et eller flere områder af patienten. Ved at supplere med en SPECT/CT tager undersøgelsen længere tid, også længere tid end at udføre en 18F-NaF PET/CT-scanning, hvilket bevirker, at 18F-NaF PET/CT kan være mere scanningstids-effektiv såfremt de knogleskintigrafier, der suppleres med SPECT/CT udgør mere end 36 % af samtlige udførte knogleskintigrafier, da er en 18F-NaF PET/CT-scanning mere tidseffektiv. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Erik S. Poulsen, MD, MSc Hovmestervej 3 st. th., DK-2400 København NV 25825835 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: ERIK S. POULSEN, HEINE SKOV. In collaboration with Sundhedsinnovation Sjælland, Næstved Hospital, Bispebjerg Hospital, and Cortrium ApS. CONSIDERATIONS WHEN STARTING A MEDTECH COMPANY The aim of this talk is to discuss the Danish healthcare system’s ability to adopt novel technologies and mobile health innovations (mHealth) in general. Common key considerations and challenges when introducing novel medical technologies into medical markets and will be discussed. These range from business aspects, hard-, and software design, through legislative requirements. Further, Danish medical device startup company, Cortrium will also be briefly introduced. Cortrium has developed a simple and inexpensive vital sign monitoring system. During the talk, this system will be live-demonstrated. Finally, preliminary results from clinical pilot studies will be presented and discussed. Fig. 1:The complete back-bone of Cortrium’s medical device vital sign monitoring system displayed. This includes a hardware sensor, iOS application, cloud service, and a frontend web administrations module. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Morten Bjørn Jensen Elmegade 10, 8200 Aarhus N 51927057 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: MORTEN H. SMERUP, PETER JOHANSEN & MORTEN B. JENSEN. Department of Engineering, Aarhus University DEVELOPMENT OF A NEW HEART VALVE PROSTHESIS CONCEPT FOR PEDIATRIC CARDIAC SURGERY In infant heart valve surgery only few therapeutic options exist and there exist no off-the-shelf valve substitute. Therefore, it would be a great advantage if a heart valve substitute could be individually constructed during surgery that exactly suits the need of the specific patients. A newly developed technique may be able to present such a novel therapeutic solution in pediatric cardiac surgery. By means of preoperative echocardiographic measurements and intraoperative assessment of key anatomical dimensions, the surgeon will be able to create an artificial heart valve made of fixated autologous pericardium during surgery. Five upscaled heart valves with varying leaflet length were tested in a pulsatile left heart in vitro model with constant pressure and heart rate and varying cardiac output. Geometric and effective orifice area, mean and peak pressure gradient, regurgitant fraction, backflow, opening and closing velocity and coaptation length were assessed through pressure and flow recordings, high speed imaging and ultrasonography. The infant valve showed good hemodynamic performance with pressure gradients comparable to gradients found for other bioprosthesis. The initial in vitro testing proofed the concept of the infant valve and showed that the hemodynamic properties varied with the geometry and have led to further development of the design concepts. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Ida Lindhardt Jensen de Mezas vej 15, 2. Tv. 28772329 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: Ida Lindhardt1, Ditte Bruus1, Jonas Rasmussen2, Marcell Tjørnild2, Tommy Bechsgaard1,2, Vibeke E. Hjortdahl2, Peter Johansen1,2 1 Cardiovascular Experimental Laboratory, Aarhus University, Department of Engineering 2 Department of Cardiothoracic and Vascular Surgery T, Aarhus University Hospital. In vitro investigation of pulmonary valve prosthesis constructed in CorMatrix in treatment of Tetralogy of Fallot Tetralogy of Fallot is a congenital heart disease with pulmonary stenosis being one of the major malformations. The surgical treatment of this condition is effective, but often requires multiple surgeries with pulmonary valve replacement, in order to avoid heart failure and arrhythmia in adulthood. The aim of this present study is to evaluate in a functional perspective the geometry of a pulmonary valve prosthesis designed and manufactured in the CorMatrix material. The pulmonary valve prostheses are installed in a pulsatile in vitro flow loop and the hemodynamic characteristics of the valves are investigated based on a number of measurements conducted under the physiological conditions present in the right side of the heart in a human adult. The in vitro model is equipped with transit time flowmeters, microtip pressure catheters, and the valve operation is captured through high-speed imaging. Hence, the valve is evaluated in means of the pressure drop during systole, the valve opening area over time, the valve leaflet coaptation height and the valve leakage (during diastole). Figure 1 shows five selected high-speed images illustrating the movements of the leaflets from valve closure to valve opening during a single heart cycle. Figure 1. High-speed images of CorMatrix valve. The overall conclusion of the in vitro part is that a feasible platform has been developed that can test and evaluate various designs with different geometrical details. Hereby, a unique setup has been made available for experimental validation of various design optimization approaches. The following step is for the valves to be tested in vivo through animal experimental studies. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Tommy Bechsgaard Finlandsgade 22, 8200 Aarhus N 22558010 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: Biomechanical description of aortic root repair procedures, preliminary results T Bechsgaard1,2, T Lindskow2, TL Sørensen2, JL Hønge2, H Nygaard2, SL Nielsen2, P Johansen1,2 1 Department of Engineering, Faculty of Science and Technology, Aarhus University, Denmark 2 Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark Objectives: Patients with aortic regurgitation secondary to ascending aortic dilation or aneurism can be treated with valve sparing techniques such as the David reimplantation or the Yacoub remodeling technique. In order to quantify the physiological impact of these two repair procedures, new force transducers have been developed and tested. Materials and Methods: New force transducers were developed, manufactured and calibrated to assess the force distribution of the aortic root repair procedures. The transducers were developed using rapid prototyping in plastic material. Miniature strain gauges were meticulously mounted on the transducer. Both transducers were calibrated under static conditions. Fresh porcine aortic roots were collected from a local slaughterhouse and installed in an in vitro model along with the force transducers. Forces from the annulus and at the commissural points of the aortic root were collected, along with blood pressure and flow, 2D echocardiography and high- speed imaging. Results and Discussion: The static calibration of the force transducers revealed a linear r2 coefficient > 0.99. The forces reported were collected at a systolic pressure of 110 mmHg with a flow of 5l/min. In the systolic phase, the preliminary forces for the native, David repair and Yacoub repair were 1.1N, 0.6N, 0.7N respectively. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Søren Nielsen Skov Grønnegade 55, 2. Lej 13 – 8000 Aarhus C 40186364 [email protected] Biomechanical Features of a Rigid Remodeling Versus a Fully Flexible Mitral Annuloplasty Ring Søren Nielsen Skov1,2,3, Diana Mathilde Røpcke1,2, Christine Ilkjær1,2, Jonas Rasmussen1,2 , Marcell Juan Tjørnild1,2, Hans Nygaard1,2, Morten Olgaard Jensen3,4 and Sten Lyager Nielsen1,2 1 Dept. of Cardiothoracic and Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark Dept. of Clinical Medicine, Aarhus University Hospital, Aarhus, Denmark 3 Dept. of Engineering, Faculty of Science and Technology, Aarhus University, Aarhus, Denmark 4 Dept. of Biomedical Engineering, Georgia Institute of Technology and Emory University, Atlanta, USA 2 Different mitral valve pathologies may require different remodelling properties of annuloplasty rings. The aim of this study was to conduct a comprehensive biomechanical assessment of the remodelling effects of a rigid versus a fully flexible mitral annuloplasty ring in-vivo. The characterization of mitral annuloplasty rings was performed in-vivo in an 80 kg porcine model. 21 animals were divided into three groups: A no ring group, a rigid ring group and a flexible ring group. Mitral annular deformational forces were measured with a novel annular force transducer optimized for simultaneous force measurements in- and out of the mitral annulus plane. Geometry was measured with a sonomicrometry ultrasound technique (11 crystals). Annular motion was significantly decreased with a rigid ring compared to the no ring and flexible ring group. Accordingly, restrictive annular motion resulted in significantly lower deformational forces measured in the rigid ring. The study is the first to demonstrate significant differences of cyclic deformation and deformational forces of rigid remodelling versus fully flexible mitral annuloplasty rings. Remodelling may act intentionally for mitral valve repair, however reduction of deformational reflects forces accumulation in the ring construction and suture attachment that potentially may lead to ring dehiscence and repair failure. No Ring (n=7) Parameter Rigid Ring (n=7) Flexible Ring (n=7) Max Min Difference Max Min Difference Max Min Difference Mitral annular area [mm2] 760 ± 114 613 ± 114 147 ± 64 685 ± 101 645 ± 92 40 ± 22* 756 ± 150 658 ± 164 98 ± 63# Mitral annular circum. [mm] 112 ± 14 100 ± 16 11 ± 5 107 ± 7 104 ± 7 3 ± 1* 107 ± 10 99 ± 10 7 ± 3# Septal-lateral distance [mm] 33 ± 2 29 ± 3 4±2 29 ± 5 28 ± 6 2 ± 2* 33 ± 4 29 ± 4 4 ± 2# Commissural distance [mm] 30 ± 4 27 ± 3 3±2 32 ± 5 30 ± 5 2±1 35 ± 4 30 ± 4 4 ± 1# Table 1: Difference (Max-Min) between *: Ring vs. no ring group; #Rigid vs. flexible ring - (p<0.05) SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Michael Væggemose Aarhus Universitetshospital 20 68 50 41 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: M. Væggemose, M. Pham, S. Ringgaard, H. Tankisi, N. Ejskjaer, P. L. Poulsen, H. Andersen Magnetic resonance diffusion tensor imaging for evaluation of Diabetic Polyneuropathy Aim To evaluate the use of magnetic resonance (MR) diffusion tensor imaging (DTI) to demonstrate nerve lesions in patients with type 1 diabetes. Methods Ten type 1 diabetic patients with polyneuropathy (+PNP), 10 type 1 diabetic patients without polyneuropathy (-PNP) and 10 healthy controls (HC) were included. Diffusion tensor images were acquired to evaluate the extent of focal lesions in the sciatic and tibial nerve using a 3 Tesla scanner. DTI fractional anisotropy (FA) and apparent diffusion coefficients (ADC) were calculated. The MR scans consisted of 16 axial slices of the sciatic nerve and the tibial nerve. The presence of PNP was determined based on nerve conduction studies, vibratory perception thresholds and clinical neurological examination. Results FA values of the sciatic nerve were significantly lower in diabetic patients with PNP compared to controls and diabetic patients without PNP, (+PNP: 0.39 (0.25-0.43), -PNP: 0.47 (0.41-0.52), HC: 0.48 (0.41-0.59)) (median, range) (p < 0.01). Furthermore, there was a difference in the ADC between the groups, (+PNP: 1611 (1382-2220), -PNP: 1489 (1389-1599), HC: 1420 (1250-1608)) (p < 0.01). Results from the tibial nerve where equivalent. Conclusion Diffusion tensor imaging of the sciatic and tibial nerve showed lower FA values and higher ADC values in diabetic patients with PNP as compared to healthy controls and non-neuropathic patients. Lower FA values and higher ADC may reflect less constriction of flow along the nerve indicating demyelination and axonal loss PNP. Fig. 1- Fibertract of sciatic nerve Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Troels Lading Fuglesangs Alle 28, st. 108. 8210 Aarhus V 51966830 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: In vitro charachterization and comparison of the David and the Yacoub aortic root repair techniques with and without a supporting annular ring Lading TS1, Røpcke DM1, Lindskov T, Bechsgaard T2, Johansen P2, Nygaard H2, Hasenkam JM1, Nielsen SL1 1 Department of Cardiothoracic & Vascular Surgery, Aarhus University Hospital, Aarhus, Denmark 2 Department of Engineering, Faculty of Science and Technology, Aarhus University, Denmark Corresponding author: troels.lading @gmail.com Objectives: The aim of this study is to compare the aortic remodeling techniques, with and without a supporting ring, in vitro, comparing biomechanics of the native aortic root and valve to the root and valve after a Yacoub and a David repair technique. In total five groups will be analyzed and compared; Native aortic root as reference, native aortic roots with a supporting annular ring, Davids reimplantation technique, Yacoubs remodeling technique and Yacoubs remodeling technique with a supporting annular ring. The measurements used for comparison are leaflet dynamics, annular and aortic force distribution and hemodynamics. Materials and Methods: Twenty-five porcine aortic roots (100 kg) will be prepared and randomized to either no aortic remodeling (n=5), no aortic remodeling with addiotional supporting annular ring (n=5), or to a David (n=5), or to a Yacoub (n=5) repair technique or to a Yacoub repair technique with addiotional supporting annular ring (n=5), which will be performed ex vivo before mounting the aortic root in the in vitro model.Two circular force transducers will be placed in the aortic annulus and at the sinotubular junction, respectively, These transducers will measure annular contraction and dilation of the root. The annulus transducer consists of six strain gauges allowing individual force measuremets at each strain gauge point of the ring. The forces at each commisure of the aortic valce will be measured by attachment of three strain gauges mounted on the transducer ring at the sinotubular junction. Microtip pressure catheters will be used for pressure measurements, and a highspeed camera will be used for digital imaging of the leaflet motion and -dynamics throughout heart cycle. Results: Pending Discussion: Biomechanical and hemodynamic analysis of the aortic root remodeling techniques, with and without a supporting ring, will hopefully provide increased insight in the remodeling technique and provide knowledge for optimizing surgical procedures for aortic root repair in the relevant patient groups. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Ali Mohebbi Søborg Hovedgade 72A, 3 tv. 2860 Søborg +4552764078 [email protected] Ali Mohebbi, Signe K.D. Engelsholm, Sadasivan Puthusserypady, Troels W. Kjaer, Carsten E. Thomsen, Helge B.D. Sorensen Technical University of Denmark, Department of Electrical Engineering A Brain Computer Interface for Robust Wheelchair Control Application Based on Pseudorandom Code Modulated Visual Evoked Potential In this pilot study, a novel and minimalistic Brain Computer Interface (BCI) based wheelchair control application was developed. In this context, a LEGO Mindstorm robot was used as a miniature version of a real wheelchair. By presenting visual stimuli to the eye, desired visual evoked potentials (VEPs) can be provoked and detected in the electroencephalogram (EEG, one channel). One useful method for generating detectable EEG patterns (c-VEP) is by coding the stimulus in repetitive pseudorandom binary sequences. The visual stimuli in the scheme were generated based on the Gold code, and the VEPs were recognized and classified using subject-specific algorithms. The intention of the user is identified by comparing recorded real-time EEG sequences with 4 predefined templates, one for each option provided on the stimulus display. The options were presented as directional targets indicating forward, backward, left and right. When a target was identified by the c-VEP based BCI system, the robot was controlled corresponding to the directional command. Ten healthy subjects were evaluated in testing the system where an average accuracy of 97% was achieved. The promising results illustrate the potential of this approach when considering a real wheelchair application. Figure 1 BCI Flow Diagram Figure 2 Classification Algorithm Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Sissel Bisgaard Grønningen 9, 4th 28990599 [email protected] Authors: Sissel Bisgaard, Bolette Duun-Christensen, Lykke Kempfner, Helge B.D. Sorensen and Poul Jennum. Abstract:The purpose of this pilot study was to develop a supportive algorithm for the detection of idiopathic Rapid Eye-Movement (REM) sleep Behaviour Disorder (iRBD) from EEG recordings. iRBD is defined as REM sleep without atonia with no current sign of neurodegenerative disease, and is one of the earliest known biomarkers of Parkinson's Disease (PD). It is currently diagnosed by polysomnography (PSG), primarily based on EMG recordings during REM sleep. The algorithm was developed using data collected from 42 control subjects and 34 iRBD subjects. A feature was developed to represent high amplitude contents of the EEG and a semi-automatic signal reduction method was introduced. The reduced feature set was used for a subject-based classification. With a subject specific re-scaling of the feature set and the use of an outlier detection classifier the algorithm reached an accuracy of 0.78. The result shows that EEG recordings contain valid information for a supportive algorithm for the detection of iRBD. Further investigation could lead to promising application of EEG recordings as a supportive source for the detection of iRBD. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Anders Esager Adresse: Grønnegade 77 St Th, 8000 Aarhus C Tlf. nr.: 42524404 E-mail: [email protected] Anders Esager, Anders Toft Andersen Aarhus University School of Engineering CELL SORTER FOR ISOLATION OF INSULIN PRODUCING CELLS Insulin is a hormone essential for regulating the absorption of glucose. A decrease in insulin production by smaller/fewer pancreatic Langerhans islets may lead to life-threatening disease, such as diabetes mellitus. To investigate this disease further, and improve understanding of the insulin regulation, many pharmaceutical companies perform experiments where islets are isolated from rats. This is done by surgically removing the pancreas, dissolving the pancreatic tissue with collagenase treatment and manually picking the islets from the suspension. This procedure is both cumbersome and time-intensive hence new ways are warranted. A robotic device was previously developed to pick the islets from the suspension in a petri dish but the accuracy was inadequate partly due to movements of the pipette in the fluid. This project aims to develop a novel system for pancreatic islet isolation. First the pancreas will be dissolved and sucked into a tube. A software program will be developed to process images taken by a microscope camera. If the islets are detected a valve mechanism will isolate the islets from the remaining fluid. This system will help reduce the cost of isolating islets and further reduce variation and damage of the cells. Fig 1.: System overview Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Mads Olsen; Caspar Aleksander Bang Jespersen Vesterbrogade X 146B 4tv, 1620; Rosenvængets Alle 27D 3tv, 2100 26180559; 31490999 [email protected]; [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: MADS OLSEN & CASPAR ALEKSANDER BANG JESPERSEN Institute for Biomedical Engineering, Technical University of Denmark APPNEA: NOVEL SMARTPHONE BASED APPLICATION FOR SLEEP APNEA DETECTION This study was a proof of concept for a low cost smart phone based system for pre-categorization of potential sleep apnea patients is shown. The objective of the study was to show how the smartphone built-in accelerometer and a bone conducting microphone can effectively be used to extract features usable in sleep apnea diagnosis. The results were very promising and certainly prove the concept. There is however still work to do before a sleep apnea detection application is ready to ship - but this study has laid the foundation. Abstrakt sendes til: [email protected] Poster-konkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Kathrine Holtz Svendborgvej 107, st. 5260 Odense M 27585525 [email protected] KATHRINE HOLTZ, LAURA MØLLER HANSEN, HANS HØGENHAVEN, LARS THOMSEN, STEFFEN HOLMGAARD OG MORTEN ØSTERGAARD ANDERSEN The Maersk Mc-Kinney Moller Institute, University of Southern Denmark EVALUATING THE USE OF EEG FOR MONITORING PATIENTS IN THE NEUROINTENSIVE CARE UNIT No one would question the importance of ECG-monitoring of heart patients, but why are patients with a devastating disease in the brain not EEG-monitored in the neurointensive care unit (NIA)? This project aimed at identifying the barriers for EEG-monitoring of patients at Odense University Hospital (OUH), suffering from Subarachnoidal hemorrhages (SAH). This was investigated through interviews with doctors from NIA that were in possession of unused EEG equipment. The second part of the project was to evaluate the possible use of this equipment by reviewing literature. The main barrier was uncertainty of how to interpret the EEG data from the equipment. Other barriers included staff training and challenges in including EEG in routine monitoring. The review uncovered conceptual confusion of SAH complications, but it appears that there is correlation between relative alpha variability of the EEG and vasospasms, and decreased alpha/delta ratio and delayed cerebral ischemia. We developed a method for extracting this ratio from clinical EEG data. Hopefully future research will give clear guidelines on how to monitor the neurointensive patients to predict complications, and give doctors time to react before deteriorations become irreversible. Fig. 1: Repeated calibration curves using a steel wire. Note that a small amount of harmonic content is included at this test velocity. TILMELDING Posterkonkurrence Medicoteknisk landsmøde Forfatter/kontaktperson: Adresse: Tlf. nr.: E-mail: Alexander Neergaard Olesen Nøddebogade 4, 5tv +45 29840968 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: ASTRID ENGBERG1, ALEXANDER NEERGAARD OLESEN1 & MORTEN MØRUP2 1 Department of Electrical Engineering, Technical University of Denmark Department of Applied Mathematics and Computer Science, Technical University of Denmark 2 NONPARAMETRIC BAYESIAN ANALYSIS OF THE MOUSE BRAIN CONNECTOME Comprehensive knowledge of brain wiring is essential for a thorough understanding of nervous system functionality. A mesocale connectome for the murine brain has recently been presented along with a linear model describing the connection strengths between various brain regions. We present an approach for modeling the mouse brain using a directed, unipartite and weighted network model based on an extended infinite relational model (IRM) framework where the inter-regional connection strengths are represented using a Gamma distribution. Statistical inference is carried out using Markov Chain Monte Carlo methods to determine cluster partitions in the network, thereby enabling model evaluation through predictive capabilities and normalized mutual information (NMI). The extended IRM is able to extract clusters corresponding to anatomical brain regions (NMI = 0.607±0.014 compared to NMI= 0.277±0.011 for random) using only data. The extended IRM also shows comparable performance to the standard IRM with respect to link prediction (AUC = 0.885±0.027), and enabled prediction of connection densities between brain regions (R2 = 0.736). These results indicate that brain connectivity in mice can be well modeled using a nonparametric Bayesian framework. Abstrakt sendes til: [email protected] SKABELON Foredragskonkurrence Medicotekniske landsmøde Forfatter/Kontakt person: Adresse: Tlf. nr.: E-mail: Thomas Lindskow Nørregade 8, 3.th 25303986 [email protected] Slet eksempel og skriv abstrakt i testruden: Alle forfattere skal anføres; foredragsholderen skal understreges, max 200 ord: Assessment and comparison of stress distribution in the aortic root: After aortic root repair using Davids or Yacoubs technique. - a clinical porcine experimental study Lindskow T1,3, Tjørnild MJ1,3, Bechsgaard T2,3, Røpcke DM1,3, Lading TS1,3, Nielsen SL1,3 1 Department of Cardiothoracic and Vascular Surgery, Aarhus University Hospital 2 Department of Biomedical Engineering, Aarhus University 3 Clinical Institute of Medicine, Aarhus University Hospital . Objectives: Recent years of research has showed that aortic valve repair is superior to valve substitution in patients with aortic regurgitation due to aortic dilatation if the valve cusps themselves are normal. The aim of this study is to assess and compare stress distribution in the aortic root after aortic root repair using two of the most commonly accepted techniques developed by Dr Tirone E. David (The David valve re-implantation procedure) and Sir Magdi Yacoub (The Yacoub re-modelling procedure), respectively. Materials and methods: Fifteen pigs (90 kg) will be randomized to either a David repair (n=5), a Yocoub repair (n=5) or no repair at all (n=5). A median sternotomy will be performed and cardiopulmonary bypass will be established followed by cardioplegia and resection of the aortic root including freedissection of the coronary buttons. Hereafter a force transducer will be sutured to the aortic annulus just below the valve. This will enable measuring of stress distribution both in plane (annulus dilation/contraction) and out of plane (annulus bending). Fifteen piezoelectric crystals for sonomicrometric measurements will be implanted at four levels around the circumference of the aortic root (three at the annular level, three at each commissure tip, three at the sinotubular junction, three in the ascending aorta, and one on each free edge of the three aortic cusps). The sonomicrometric crystals will display 3D geometry of the changes in the aortic root. Two microtip pressure catheters will be inserted in the left ventricle and atrium for direct pressure measurements. After weaning from cardiopulmonary bypass and hemodynamic stabilization, data will be collected over 10 cardiac cycles. Force distribution and 3D configuration/behavior of the aortic root will be described and compared between groups. Results: Results are pending. Conclusion: With this study we hope to gain more knowledge about the normal aortic root and also gain insight into different repair techniques, hopefully enabling surgeons to choose the right repair technique for each patient, depending on pathology and aortic root anatomy. Abstrakt sendes til: [email protected]
© Copyright 2024