Startseite Wear of a total intervertebral disc prosthesis
Artikel Open Access

Wear of a total intervertebral disc prosthesis

Abrasion tests of a tribological system of total intervertebral disc prosthesis with dampening characteristics
  • Carina Micheler , Erhard Krampe EMAIL logo , Peter Foehr , Miriam Haerst und Rainer Burgkart
Veröffentlicht/Copyright: 30. September 2016
Artikel downloaden (PDF)
Veröffentlichen auch Sie bei De Gruyter Brill
Informationen für Autor*innen Erkunden Sie dieses Fachgebiet
Current Directions in Biomedical Engineering
Aus der Zeitschrift Current Directions in Biomedical Engineering Band 2 Heft 1

Abstract

In this study we characterized the wear behavior of a tribological system with material combinations of the total intervertebral disc prosthesis InDisc (Institute of Medical and Polymer Engineering) – consisting of two laser sintered titanium alloy plates with an elastomer inbetween. For the tests a translatory oscillation test bench was used which simulates the kinematic and the physiological environment of the lumbar spine. In the interface between the elastomer (Silopren LSR 2670) and the laser sintered titanium alloy (Ti6Al4V) abrasion cords out of silicone rubber with a maximal area of 500 × 700 μm2 were generated as well as individual particles with a size of 10 × 20 to 40 × 50 μm2. In the second prosthesis interface of Ti6Al4V and bone, bone particles with an area of 0.5 × 0.5 to 1 × 1 μm2 were detected. The wear particles and the amount of wear volume influence the biological response of a total intervertebral disc prosthesis in the body.

Keywords: backache; intervertebral disc; intervertebral disc prosthesis; wear and wear particle

1 Introduction

Backache is a widespread disease in Germany [1] mainly caused by degenerative changes of the intervertebral disc and the rise of sedentary activities [2]. Current treatments for backache are medication and conservative physiotherapy or surgical methods [3]. If conservative physiotherapy achieves no pain relief or there is already a herniated disc, surgical treatments will be performed, e.g. cages for fusion or mobility-retaining total intervertebral disc prostheses are implanted. The standard treatment is the fusion of the vertebral segment [4]. Meanwhile a rising number of intervertebral disc prostheses are implanted and therefore it is necessary to follow up the wear behaviour of total intervertebral disc prosthesis since wear particles can result in foreign body reactions and loosening of the implant from the corresponding bone.

2 Methods

2.1 Total intervertebral disc prosthesis

The total intervertebral disc prosthesis InDisc of the Institute of Medical and Polymer Engineering (Figure 1A) for the lumbar disc between the vertebral bodies L4 and L5 consist of two endplates with a porous structure for osseointegration and a flexible silicone (Silopren LSR 2670, Momentive Performance Materials) component, which imitates the dampening characteristics of the anatomical disc. The silicone is a liquid silicone rubber for injection mould purpose and has a hardness of 70 Shore A. The endplates are made of the titanium alloy Ti6Al4V by direct metal laser sintering [5].

Figure 1 Intervertebral disc prosthesis InDisc: (A) CAD-model, (B) Interfaces of InDisc: (1) Ti6Al4V – LSR 2670, (2) Ti6Al4V – vertebral body.
Figure 1

Intervertebral disc prosthesis InDisc: (A) CAD-model, (B) Interfaces of InDisc: (1) Ti6Al4V – LSR 2670, (2) Ti6Al4V – vertebral body.

Due to the ease of accessibility technical silicone was used as in a medical grade silicone, the same abrasion characteristics can be expected.

2.2 Interfaces

The two interfaces of the InDisc prosthesis (Figure 1B) were examined, the titanium alloy Ti6Al4V with a laser sintering respectively rapid prototyping surface (further referred to as “RP”) and the hardened silicone LSR 2670 and the second interface Ti6Al4V with a bone-like porous structure (further referred to as “por”) and the cortical bone of the vertebral body of a bovine cervical spine. Furthermore the friction behaviour between Ti6Al4V RP and bone (cortical and cancellous bone, respectively) were also compared.

2.3 Experimental setup

For the analysis of the wear behaviour a translatory oscillation test bench was used with the test specimens pin and the plate material (Figure 2). The cyclic test applied a shear load to the specimen. This shear load was induced by a predefined normal force (axial compression) that was adjusted via a load cell. To allow an indenter movement along the normal axis a proportional spring was additionally integrated into the loading chain. The wear amplitude in anterior-posterior direction was set by an adjustable eccentric. The test duration was determined by the frequency and the number of loading cycles, which was defined with respect to the material combination (Table 1). To simulate a physiological environment, constructs were placed in a specimen chamber, fully covered with Ringer’s solution and heated up to a temperature of 37°C. All tests were performed at a frequency of 2 Hz, a normal force of 100 N and wear amplitude of 1 mm. [6]

Figure 2 Test bench: (A) experimental setup: (1) predefined normal force, (2) adjustable eccentric, (3) rev counter, (4) axial compensation and bearing, (5) motor and gear, (B) detailed view of the specimen chamber, (C) test specimen.
Figure 2

Test bench: (A) experimental setup: (1) predefined normal force, (2) adjustable eccentric, (3) rev counter, (4) axial compensation and bearing, (5) motor and gear, (B) detailed view of the specimen chamber, (C) test specimen.

Table 1

Results for different loading setups and constructs.

No.ComponentsCyclesWear Vol. (mm3)Wear Rate (mm3/Nm)
1Ti (RP)/LSR 2670750,00014.15931.59E-05
2Ti (RP)/LSR 2670750,00011.50426.59E-05
3Ti (RP)/cortical375,00059.667268.32E-05
4Ti (RP)/cortical375,00066.333301.86E-05
5Ti (por)/cortical125,000––
6Ti (por)/cortical125,000––
7Ti (RP)/cancellous125,0006.33386.58E-05

Ti, Ti6Al4V; RP, Rapid Prototyping; por, porous topography; Cortical, cortical bone; Cancellous, cancellous bone Loading duration (cycles), wear volume (mm2) and wear rate (mm2/Nm).

2.4 Wear analysis

After the wear simulation tests the topography of the friction partners, the amount of abrasion and the wear particles were analysed (Table 1). The analysis of the topography was performed by using a light microscope with a magnification of 100 to 800-fold.

The amount of abrasion was determined by the weight measurement of the test specimens before and after the simulation with a high-precision scale. However, this method only works with the titanium and silicone specimen, but not with the bone preparations, because the weight components of the bone marrow were extracted by the surrounding medium. This made the weight measurement of the samples obsolete. To measure the weight of the particles using filters is an alternative method to determine the amount of abrasion. The filters are utilized to extract the particles from the Ringer’s solution. However, this method is more imprecise compared to the first method, since particles of the environment are also in the filters. By using reference experiments, a factor can be determined to subtract the extra weight. Since this method is still inaccurate, the determined values are only seen as reference values.

For the characterization of the wear particles sections of the filter paper were examined by scanning electron microscope.

3 Results

3.1 Ti6Al4V and LSR 2670

In the friction tests with Ti6Al4V RP and LSR 2670 an abrasive wear of silicone was generated with the wear rate of 31.59E-05 or 26.59E-05 mm3/Nm. The wear is mainly presented as abrasive cords, which form a clew (Figure 4).

The clews were measured and have an area of approximately 200 × 300 to 500 × 700 μm2. In addition to the abrasion cords individual particles were detected, which have a size range of 10 × 20 up to 40 × 50 μm2. During the experiments the topography of the two test specimens changed. The titanium pins before the tests had a rough surface due to the direct metal laser sintering process and were smoothed by the tribological stress and showed grooves in sliding direction. The silicone surface had the same grooves (Figure 3).

Figure 3 Results Ti6Al4V – LSR 2670: Ti6Al4V surface (A) before and (B) after wear simulation, LSR 2670 surface (C) before and (D) after wear simulation (scale bars represent 50 μm, arrows indicate the sliding direction).
Figure 3

Results Ti6Al4V – LSR 2670: Ti6Al4V surface (A) before and (B) after wear simulation, LSR 2670 surface (C) before and (D) after wear simulation (scale bars represent 50 μm, arrows indicate the sliding direction).

Figure 4 Scanning electron microscopy (SEM) of an abrasion cord to measure the particle size after filtration at different magnitues (A: ×100, B: ×500).
Figure 4

Scanning electron microscopy (SEM) of an abrasion cord to measure the particle size after filtration at different magnitues (A: ×100, B: ×500).

3.2 Ti6Al4V and bone

The combinations of Ti6Al4V RP with cortical and cancellous bone generated bone particles with a size of 0.5 × 0.5 to 1 × 1 μm2 (Figure 6). The titanium pins showed the same topographical change as in the tests with silicone and the bone specimens had grooves in the sliding direction (Figure 5).

Figure 5 Grooves in sliding direction after abrasion tests in (A) Ti6Al4V (×100) and (B) cortical bone (×800) (arrows indicate the sliding direction).
Figure 5

Grooves in sliding direction after abrasion tests in (A) Ti6Al4V (×100) and (B) cortical bone (×800) (arrows indicate the sliding direction).

Figure 6 Covered filter paper with a giant amount of cortical bone-meal (SEM), circles: highlighted individual particles for measurement.
Figure 6

Covered filter paper with a giant amount of cortical bone-meal (SEM), circles: highlighted individual particles for measurement.

The tests with cortical bone had a wear rate of 268.32E-05 or 301.86E-05 mm3/Nm. In contrast the friction pairing with cancellous bone had a lower wear rate of 86.58E-05 mm3/Nm.

In the experiments with the trabecular-like structured Ti6Al4V and cortical bone no correct wear rate could be determined due to the catching of the structure in the cortical bone. Despite that bone particles that were broken out were discovered with the maximum size of 100 × 100 μm2.

4 Discussion

The experiments between Ti6Al4V and silicone have a 4–5 times higher wear rate due to the rapid prototyping surface compared to the literature [5] without a rapid prototyping surface.

The wear tests with cortical bone compared to cancellous bone have approximately a 3-fold wear rate.The higher wear rate can be explained by the higher proportion of bone tissue per volume fraction in the corical bone.

The biological response to wear particles depends on its kind and amount. Macrophages and giant cells in the periprosthetic membrane absorb the non-degradable particles and thus lead to a tissue formation and associated osteolysis, which can initiate aseptic loosening.

Acknowledgement

Special thanks to eos GmbH (Krailling), Momentive Performance Materials (Leverkusen), Dr. Handwerker from Henkel AG & Co. KGaA (Garching), Metzgerei Blösch (Niederraunau) and Dr.-Ing. Obst from the Department of Orthopaedics at Technical University of Munich (Munich).

Author’s Statement

Research funding: This study was co-funded by the German Federal Ministry of Education and Research (BMBF) with grant number 0315577C (Funktionale Qualitätssicherung für regenerative Gewebeersatzmaterialien für Knorpel und Meniskus – QuReGe). Conflict of interest: Authors state no conflict of interest. Material and Methods: Informed consent: Informed consent has been obtained from all individuals included in this study. Ethical approval: The conducted research is not related to either human or animal use.

References

[1] Raspe H. Gesundheitsberichterstattung des Bundes: Heft 53: Rückenschmerzen, 1. Berlin: Auflage, Robert Koch-Institut; 2012.Suche in Google Scholar

[2] Zimmer A, Reith W. Diagnostik und Therapie des Bandscheibenvorfalls. Berlin: Springer Verlag; 2014.10.1007/s00117-014-2726-3Suche in Google Scholar PubMed

[3] Mathey M, Wintermantel E. Implantate für den Bandscheibenersatz. In: Wintermantel E, Ha S-W. editors: Medizintechnik. 5. Berlin: Springer Verlag; 2009, p. 1739–51.10.1007/978-3-540-93936-8_76Suche in Google Scholar

[4] Vicars R, Hall R, Fisher J. Wear: total intervertebral disc prostheses. Comprehensive Biomaterials. 2011;6:191–205.10.1016/B978-0-08-055294-1.00212-9Suche in Google Scholar

[5] Krampe E, Haerst M, Wintermantel E. Entwicklung einer patientenoptimierten Bandscheibentotalendoprothese – Von einer Idee zum Implantatkonzept. Kunststoffe in der Medizintechnik, VDI-Gesellschaft Kunststofftechnik. 2016;163–79.10.51202/9783182443469-163Suche in Google Scholar

[6] Micheler C. Charakterisierung des Abriebs bei der tribologischen Belastung der Werkstoffpaarungen einer Bandscheibentotalendoprothese, unpublished thesis, TU München; 2015.Suche in Google Scholar

[7] Pylios T, Shepherd DET. Wear of medical grade silicone rubber against titanium and ultrahigh molecular weight polyethylene. J Biomed Mater Res B Appl Biomater. 2008;84B:520–3.10.1002/jbm.b.30899Suche in Google Scholar PubMed

Published Online: 2016-9-30
Published in Print: 2016-9-1

©2016 Erhard Krampe et al., licensee De Gruyter.

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Artikel in diesem Heft

  1. Synthesis and characterization of PIL/pNIPAAm hybrid hydrogels
  2. Novel blood protein based scaffolds for cardiovascular tissue engineering
  3. Cell adhesion and viability of human endothelial cells on electrospun polymer scaffolds
  4. Effects of heat treatment and welding process on superelastic behaviour and microstructure of micro electron beam welded NiTi
  5. Long-term stable modifications of silicone elastomer for improved hemocompatibility
  6. The effect of thermal treatment on the mechanical properties of PLLA tubular specimens
  7. Biocompatible wear-resistant thick ceramic coating
  8. Protection of active implant electronics with organosilicon open air plasma coating for plastic overmolding
  9. Examination of dielectric strength of thin Parylene C films under various conditions
  10. Open air plasma deposited antimicrobial SiOx/TiOx composite films for biomedical applications
  11. Systemic analysis about residual chloroform in PLLA films
  12. A macrophage model of osseointegration
  13. Towards in silico prognosis using big data
  14. Technical concept and evaluation of a novel shoulder simulator with adaptive muscle force generation and free motion
  15. Usability evaluation of a locomotor therapy device considering different strategies
  16. Hypoxia-on-a-chip
  17. Integration of a semi-automatic in-vitro RFA procedure into an experimental setup
  18. Fabrication of MEMS-based 3D-μECoG-MEAs
  19. High speed digital interfacing for a neural data acquisition system
  20. Bionic forceps for the handling of sensitive tissue
  21. Experimental studies on 3D printing of barium titanate ceramics for medical applications
  22. Patient specific root-analogue dental implants – additive manufacturing and finite element analysis
  23. 3D printing – a key technology for tailored biomedical cell culture lab ware
  24. 3D printing of hydrogels in a temperature controlled environment with high spatial resolution
  25. Biocompatibility of photopolymers for additive manufacturing
  26. Biochemical piezoresistive sensors based on pH- and glucose-sensitive hydrogels for medical applications
  27. Novel wireless measurement system of pressure dedicated to in vivo studies
  28. Portable auricular device for real-time swallow and chew detection
  29. Detection of miRNA using a surface plasmon resonance biosensor and antibody amplification
  30. Simulation and evaluation of stimulation scenarios for targeted vestibular nerve excitation
  31. Deep brain stimulation: increasing efficiency by alternative waveforms
  32. Prediction of immediately occurring microsleep events from brain electric signals
  33. Determining cardiac vagal threshold from short term heart rate complexity
  34. Classification of cardiac excitation patterns during atrial fibrillation
  35. An algorithm to automatically determine the cycle length coverage to identify rotational activity during atrial fibrillation – a simulation study
  36. Deriving respiration from high resolution 12-channel-ECG during cycling exercise
  37. Reducing of gradient induced artifacts on the ECG signal during MRI examinations using Wilcoxon filter
  38. Automatic detection and mapping of double potentials in intracardiac electrograms
  39. Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring
  40. Postprocessing algorithm for automated analysis of pelvic intraoperative neuromonitoring signals
  41. Best practice: surgeon driven application in pelvic operations
  42. Vasomotor assessment by camera-based photoplethysmography
  43. Classification of morphologic changes in photoplethysmographic waveforms
  44. Novel computation of pulse transit time from multi-channel PPG signals by wavelet transform
  45. Efficient design of FIR filter based low-pass differentiators for biomedical signal processing
  46. Nonlinear causal influences assessed by mutual compression entropy
  47. Comparative study of methods for solving the correspondence problem in EMD applications
  48. fNIRS for future use in auditory diagnostics
  49. Semi-automated detection of fractional shortening in zebrafish embryo heart videos
  50. Blood pressure measurement on the cheek
  51. Derivation of the respiratory rate from directly and indirectly measured respiratory signals using autocorrelation
  52. Left cardiac atrioventricular delay and inter-ventricular delay in cardiac resynchronization therapy responder and non-responder
  53. An automatic systolic peak detector of blood pressure waveforms using 4th order cumulants
  54. Real-time QRS detection using integrated variance for ECG gated cardiac MRI
  55. Preprocessing of unipolar signals acquired by a novel intracardiac mapping system
  56. In-vitro experiments to characterize ventricular electromechanics
  57. Continuous non-invasive monitoring of blood pressure in the operating room: a cuffless optical technology at the fingertip
  58. Application of microwave sensor technology in cardiovascular disease for plaque detection
  59. Artificial blood circulatory and special Ultrasound Doppler probes for detecting and sizing gaseous embolism
  60. Detection of microsleep events in a car driving simulation study using electrocardiographic features
  61. A method to determine the kink resistance of stents and stent delivery systems according to international standards
  62. Comparison of stented bifurcation and straight vessel 3D-simulation with a prior simulated velocity profile inlet
  63. Transient Euler-Lagrange/DEM simulation of stent thrombosis
  64. Automated control of the laser welding process of heart valve scaffolds
  65. Automation of a test bench for accessing the bendability of electrospun vascular grafts
  66. Influence of storage conditions on the release of growth factors in platelet-rich blood derivatives
  67. Cryopreservation of cells using defined serum-free cryoprotective agents
  68. New bioreactor vessel for tissue engineering of human nasal septal chondrocytes
  69. Determination of the membrane hydraulic permeability of MSCs
  70. Climate retainment in carbon dioxide incubators
  71. Multiple factors influencing OR ventilation system effectiveness
  72. Evaluation of an app-based stress protocol
  73. Medication process in Styrian hospitals
  74. Control tower to surgical theater
  75. Development of a skull phantom for the assessment of implant X-ray visibility
  76. Surgical navigation with QR codes
  77. Investigation of the pressure gradient of embolic protection devices
  78. Computer assistance in femoral derotation osteotomy: a bottom-up approach
  79. Automatic depth scanning system for 3D infrared thermography
  80. A service for monitoring the quality of intraoperative cone beam CT images
  81. Resectoscope with an easy to use twist mechanism for improved handling
  82. In vitro simulation of distribution processes following intramuscular injection
  83. Adjusting inkjet printhead parameters to deposit drugs into micro-sized reservoirs
  84. A flexible standalone system with integrated sensor feedback for multi-pad electrode FES of the hand
  85. Smart control for functional electrical stimulation with optimal pulse intensity
  86. Tactile display on the remaining hand for unilateral hand amputees
  87. Effects of sustained electrical stimulation on spasticity assessed by the pendulum test
  88. An improved tracking framework for ultrasound probe localization in image-guided radiosurgery
  89. Improvement of a subviral particle tracker by the use of a LAP-Kalman-algorithm
  90. Learning discriminative classification models for grading anal intraepithelial neoplasia
  91. Regularization of EIT reconstruction based on multi-scales wavelet transforms
  92. Assessing MRI susceptibility artefact through an indicator of image distortion
  93. EyeGuidance – a computer controlled system to guide eye movements
  94. A framework for feedback-based segmentation of 3D image stacks
  95. Doppler optical coherence tomography as a promising tool for detecting fluid in the human middle ear
  96. 3D Local in vivo Environment (LivE) imaging for single cell protein analysis of bone tissue
  97. Inside-Out access strategy using new trans-vascular catheter approach
  98. US/MRI fusion with new optical tracking and marker approach for interventional procedures inside the MRI suite
  99. Impact of different registration methods in MEG source analysis
  100. 3D segmentation of thyroid ultrasound images using active contours
  101. Designing a compact MRI motion phantom
  102. Cerebral cortex classification by conditional random fields applied to intraoperative thermal imaging
  103. Classification of indirect immunofluorescence images using thresholded local binary count features
  104. Analysis of muscle fatigue conditions using time-frequency images and GLCM features
  105. Numerical evaluation of image parameters of ETR-1
  106. Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV) experimentation
  107. Effect of the number of electrodes on the reconstructed lung shape in electrical impedance tomography
  108. Hardware dependencies of GPU-accelerated beamformer performances for microwave breast cancer detection
  109. Computer assisted assessment of progressing osteoradionecrosis of the jaw for clinical diagnosis and treatment
  110. Evaluation of reconstruction parameters of electrical impedance tomography on aorta detection during saline bolus injection
  111. Evaluation of open-source software for the lung segmentation
  112. Automatic determination of lung features of CF patients in CT scans
  113. Image analysis of self-organized multicellular patterns
  114. Effect of key parameters on synthesis of superparamagnetic nanoparticles (SPIONs)
  115. Radiopacity assessment of neurovascular implants
  116. Development of a desiccant based dielectric for monitoring humidity conditions in miniaturized hermetic implantable packages
  117. Development of an artifact-free aneurysm clip
  118. Enhancing the regeneration of bone defects by alkalizing the peri-implant zone – an in vitro approach
  119. Rapid prototyping of replica knee implants for in vitro testing
  120. Protecting ultra- and hyperhydrophilic implant surfaces in dry state from loss of wettability
  121. Advanced wettability analysis of implant surfaces
  122. Patient-specific hip prostheses designed by surgeons
  123. Plasma treatment on novel carbon fiber reinforced PEEK cages to enhance bioactivity
  124. Wear of a total intervertebral disc prosthesis
  125. Digital health and digital biomarkers – enabling value chains on health data
  126. Usability in the lifecycle of medical software development
  127. Influence of different test gases in a non-destructive 100% quality control system for medical devices
  128. Device development guided by user satisfaction survey on auricular vagus nerve stimulation
  129. Empirical assessment of the time course of innovation in biomedical engineering: first results of a comparative approach
  130. Effect of left atrial hypertrophy on P-wave morphology in a computational model
  131. Simulation of intracardiac electrograms around acute ablation lesions
  132. Parametrization of activation based cardiac electrophysiology models using bidomain model simulations
  133. Assessment of nasal resistance using computational fluid dynamics
  134. Resistance in a non-linear autoregressive model of pulmonary mechanics
  135. Inspiratory and expiratory elastance in a non-linear autoregressive model of pulmonary mechanics
  136. Determination of regional lung function in cystic fibrosis using electrical impedance tomography
  137. Development of parietal bone surrogates for parietal graft lift training
  138. Numerical simulation of mechanically stimulated bone remodelling
  139. Conversion of engineering stresses to Cauchy stresses in tensile and compression tests of thermoplastic polymers
  140. Numerical examinations of simplified spondylodesis models concerning energy absorption in magnetic resonance imaging
  141. Principle study on the signal connection at transabdominal fetal pulse oximetry
  142. Influence of Siluron® insertion on model drug distribution in the simulated vitreous body
  143. Evaluating different approaches to identify a three parameter gas exchange model
  144. Effects of fibrosis on the extracellular potential based on 3D reconstructions from histological sections of heart tissue
  145. From imaging to hemodynamics – how reconstruction kernels influence the blood flow predictions in intracranial aneurysms
  146. Flow optimised design of a novel point-of-care diagnostic device for the detection of disease specific biomarkers
  147. Improved FPGA controlled artificial vascular system for plethysmographic measurements
  148. Minimally spaced electrode positions for multi-functional chest sensors: ECG and respiratory signal estimation
  149. Automated detection of alveolar arches for nasoalveolar molding in cleft lip and palate treatment
  150. Control scheme selection in human-machine- interfaces by analysis of activity signals
  151. Event-based sampling for reducing communication load in realtime human motion analysis by wireless inertial sensor networks
  152. Automatic pairing of inertial sensors to lower limb segments – a plug-and-play approach
  153. Contactless respiratory monitoring system for magnetic resonance imaging applications using a laser range sensor
  154. Interactive monitoring system for visual respiratory biofeedback
  155. Development of a low-cost senor based aid for visually impaired people
  156. Patient assistive system for the shoulder joint
  157. A passive beating heart setup for interventional cardiology training
https://doi.org/10.1515/cdbme-2016-0127
Schlagwörter für diesen Artikel
backache; intervertebral disc; intervertebral disc prosthesis; wear and wear particle
Creative Commons
BY-NC-ND 4.0

Artikel in diesem Heft

  1. Synthesis and characterization of PIL/pNIPAAm hybrid hydrogels
  2. Novel blood protein based scaffolds for cardiovascular tissue engineering
  3. Cell adhesion and viability of human endothelial cells on electrospun polymer scaffolds
  4. Effects of heat treatment and welding process on superelastic behaviour and microstructure of micro electron beam welded NiTi
  5. Long-term stable modifications of silicone elastomer for improved hemocompatibility
  6. The effect of thermal treatment on the mechanical properties of PLLA tubular specimens
  7. Biocompatible wear-resistant thick ceramic coating
  8. Protection of active implant electronics with organosilicon open air plasma coating for plastic overmolding
  9. Examination of dielectric strength of thin Parylene C films under various conditions
  10. Open air plasma deposited antimicrobial SiOx/TiOx composite films for biomedical applications
  11. Systemic analysis about residual chloroform in PLLA films
  12. A macrophage model of osseointegration
  13. Towards in silico prognosis using big data
  14. Technical concept and evaluation of a novel shoulder simulator with adaptive muscle force generation and free motion
  15. Usability evaluation of a locomotor therapy device considering different strategies
  16. Hypoxia-on-a-chip
  17. Integration of a semi-automatic in-vitro RFA procedure into an experimental setup
  18. Fabrication of MEMS-based 3D-μECoG-MEAs
  19. High speed digital interfacing for a neural data acquisition system
  20. Bionic forceps for the handling of sensitive tissue
  21. Experimental studies on 3D printing of barium titanate ceramics for medical applications
  22. Patient specific root-analogue dental implants – additive manufacturing and finite element analysis
  23. 3D printing – a key technology for tailored biomedical cell culture lab ware
  24. 3D printing of hydrogels in a temperature controlled environment with high spatial resolution
  25. Biocompatibility of photopolymers for additive manufacturing
  26. Biochemical piezoresistive sensors based on pH- and glucose-sensitive hydrogels for medical applications
  27. Novel wireless measurement system of pressure dedicated to in vivo studies
  28. Portable auricular device for real-time swallow and chew detection
  29. Detection of miRNA using a surface plasmon resonance biosensor and antibody amplification
  30. Simulation and evaluation of stimulation scenarios for targeted vestibular nerve excitation
  31. Deep brain stimulation: increasing efficiency by alternative waveforms
  32. Prediction of immediately occurring microsleep events from brain electric signals
  33. Determining cardiac vagal threshold from short term heart rate complexity
  34. Classification of cardiac excitation patterns during atrial fibrillation
  35. An algorithm to automatically determine the cycle length coverage to identify rotational activity during atrial fibrillation – a simulation study
  36. Deriving respiration from high resolution 12-channel-ECG during cycling exercise
  37. Reducing of gradient induced artifacts on the ECG signal during MRI examinations using Wilcoxon filter
  38. Automatic detection and mapping of double potentials in intracardiac electrograms
  39. Modeling the pelvic region for non-invasive pelvic intraoperative neuromonitoring
  40. Postprocessing algorithm for automated analysis of pelvic intraoperative neuromonitoring signals
  41. Best practice: surgeon driven application in pelvic operations
  42. Vasomotor assessment by camera-based photoplethysmography
  43. Classification of morphologic changes in photoplethysmographic waveforms
  44. Novel computation of pulse transit time from multi-channel PPG signals by wavelet transform
  45. Efficient design of FIR filter based low-pass differentiators for biomedical signal processing
  46. Nonlinear causal influences assessed by mutual compression entropy
  47. Comparative study of methods for solving the correspondence problem in EMD applications
  48. fNIRS for future use in auditory diagnostics
  49. Semi-automated detection of fractional shortening in zebrafish embryo heart videos
  50. Blood pressure measurement on the cheek
  51. Derivation of the respiratory rate from directly and indirectly measured respiratory signals using autocorrelation
  52. Left cardiac atrioventricular delay and inter-ventricular delay in cardiac resynchronization therapy responder and non-responder
  53. An automatic systolic peak detector of blood pressure waveforms using 4th order cumulants
  54. Real-time QRS detection using integrated variance for ECG gated cardiac MRI
  55. Preprocessing of unipolar signals acquired by a novel intracardiac mapping system
  56. In-vitro experiments to characterize ventricular electromechanics
  57. Continuous non-invasive monitoring of blood pressure in the operating room: a cuffless optical technology at the fingertip
  58. Application of microwave sensor technology in cardiovascular disease for plaque detection
  59. Artificial blood circulatory and special Ultrasound Doppler probes for detecting and sizing gaseous embolism
  60. Detection of microsleep events in a car driving simulation study using electrocardiographic features
  61. A method to determine the kink resistance of stents and stent delivery systems according to international standards
  62. Comparison of stented bifurcation and straight vessel 3D-simulation with a prior simulated velocity profile inlet
  63. Transient Euler-Lagrange/DEM simulation of stent thrombosis
  64. Automated control of the laser welding process of heart valve scaffolds
  65. Automation of a test bench for accessing the bendability of electrospun vascular grafts
  66. Influence of storage conditions on the release of growth factors in platelet-rich blood derivatives
  67. Cryopreservation of cells using defined serum-free cryoprotective agents
  68. New bioreactor vessel for tissue engineering of human nasal septal chondrocytes
  69. Determination of the membrane hydraulic permeability of MSCs
  70. Climate retainment in carbon dioxide incubators
  71. Multiple factors influencing OR ventilation system effectiveness
  72. Evaluation of an app-based stress protocol
  73. Medication process in Styrian hospitals
  74. Control tower to surgical theater
  75. Development of a skull phantom for the assessment of implant X-ray visibility
  76. Surgical navigation with QR codes
  77. Investigation of the pressure gradient of embolic protection devices
  78. Computer assistance in femoral derotation osteotomy: a bottom-up approach
  79. Automatic depth scanning system for 3D infrared thermography
  80. A service for monitoring the quality of intraoperative cone beam CT images
  81. Resectoscope with an easy to use twist mechanism for improved handling
  82. In vitro simulation of distribution processes following intramuscular injection
  83. Adjusting inkjet printhead parameters to deposit drugs into micro-sized reservoirs
  84. A flexible standalone system with integrated sensor feedback for multi-pad electrode FES of the hand
  85. Smart control for functional electrical stimulation with optimal pulse intensity
  86. Tactile display on the remaining hand for unilateral hand amputees
  87. Effects of sustained electrical stimulation on spasticity assessed by the pendulum test
  88. An improved tracking framework for ultrasound probe localization in image-guided radiosurgery
  89. Improvement of a subviral particle tracker by the use of a LAP-Kalman-algorithm
  90. Learning discriminative classification models for grading anal intraepithelial neoplasia
  91. Regularization of EIT reconstruction based on multi-scales wavelet transforms
  92. Assessing MRI susceptibility artefact through an indicator of image distortion
  93. EyeGuidance – a computer controlled system to guide eye movements
  94. A framework for feedback-based segmentation of 3D image stacks
  95. Doppler optical coherence tomography as a promising tool for detecting fluid in the human middle ear
  96. 3D Local in vivo Environment (LivE) imaging for single cell protein analysis of bone tissue
  97. Inside-Out access strategy using new trans-vascular catheter approach
  98. US/MRI fusion with new optical tracking and marker approach for interventional procedures inside the MRI suite
  99. Impact of different registration methods in MEG source analysis
  100. 3D segmentation of thyroid ultrasound images using active contours
  101. Designing a compact MRI motion phantom
  102. Cerebral cortex classification by conditional random fields applied to intraoperative thermal imaging
  103. Classification of indirect immunofluorescence images using thresholded local binary count features
  104. Analysis of muscle fatigue conditions using time-frequency images and GLCM features
  105. Numerical evaluation of image parameters of ETR-1
  106. Fabrication of a compliant phantom of the human aortic arch for use in Particle Image Velocimetry (PIV) experimentation
  107. Effect of the number of electrodes on the reconstructed lung shape in electrical impedance tomography
  108. Hardware dependencies of GPU-accelerated beamformer performances for microwave breast cancer detection
  109. Computer assisted assessment of progressing osteoradionecrosis of the jaw for clinical diagnosis and treatment
  110. Evaluation of reconstruction parameters of electrical impedance tomography on aorta detection during saline bolus injection
  111. Evaluation of open-source software for the lung segmentation
  112. Automatic determination of lung features of CF patients in CT scans
  113. Image analysis of self-organized multicellular patterns
  114. Effect of key parameters on synthesis of superparamagnetic nanoparticles (SPIONs)
  115. Radiopacity assessment of neurovascular implants
  116. Development of a desiccant based dielectric for monitoring humidity conditions in miniaturized hermetic implantable packages
  117. Development of an artifact-free aneurysm clip
  118. Enhancing the regeneration of bone defects by alkalizing the peri-implant zone – an in vitro approach
  119. Rapid prototyping of replica knee implants for in vitro testing
  120. Protecting ultra- and hyperhydrophilic implant surfaces in dry state from loss of wettability
  121. Advanced wettability analysis of implant surfaces
  122. Patient-specific hip prostheses designed by surgeons
  123. Plasma treatment on novel carbon fiber reinforced PEEK cages to enhance bioactivity
  124. Wear of a total intervertebral disc prosthesis
  125. Digital health and digital biomarkers – enabling value chains on health data
  126. Usability in the lifecycle of medical software development
  127. Influence of different test gases in a non-destructive 100% quality control system for medical devices
  128. Device development guided by user satisfaction survey on auricular vagus nerve stimulation
  129. Empirical assessment of the time course of innovation in biomedical engineering: first results of a comparative approach
  130. Effect of left atrial hypertrophy on P-wave morphology in a computational model
  131. Simulation of intracardiac electrograms around acute ablation lesions
  132. Parametrization of activation based cardiac electrophysiology models using bidomain model simulations
  133. Assessment of nasal resistance using computational fluid dynamics
  134. Resistance in a non-linear autoregressive model of pulmonary mechanics
  135. Inspiratory and expiratory elastance in a non-linear autoregressive model of pulmonary mechanics
  136. Determination of regional lung function in cystic fibrosis using electrical impedance tomography
  137. Development of parietal bone surrogates for parietal graft lift training
  138. Numerical simulation of mechanically stimulated bone remodelling
  139. Conversion of engineering stresses to Cauchy stresses in tensile and compression tests of thermoplastic polymers
  140. Numerical examinations of simplified spondylodesis models concerning energy absorption in magnetic resonance imaging
  141. Principle study on the signal connection at transabdominal fetal pulse oximetry
  142. Influence of Siluron® insertion on model drug distribution in the simulated vitreous body
  143. Evaluating different approaches to identify a three parameter gas exchange model
  144. Effects of fibrosis on the extracellular potential based on 3D reconstructions from histological sections of heart tissue
  145. From imaging to hemodynamics – how reconstruction kernels influence the blood flow predictions in intracranial aneurysms
  146. Flow optimised design of a novel point-of-care diagnostic device for the detection of disease specific biomarkers
  147. Improved FPGA controlled artificial vascular system for plethysmographic measurements
  148. Minimally spaced electrode positions for multi-functional chest sensors: ECG and respiratory signal estimation
  149. Automated detection of alveolar arches for nasoalveolar molding in cleft lip and palate treatment
  150. Control scheme selection in human-machine- interfaces by analysis of activity signals
  151. Event-based sampling for reducing communication load in realtime human motion analysis by wireless inertial sensor networks
  152. Automatic pairing of inertial sensors to lower limb segments – a plug-and-play approach
  153. Contactless respiratory monitoring system for magnetic resonance imaging applications using a laser range sensor
  154. Interactive monitoring system for visual respiratory biofeedback
  155. Development of a low-cost senor based aid for visually impaired people
  156. Patient assistive system for the shoulder joint
  157. A passive beating heart setup for interventional cardiology training
Jetzt anmelden und 20% sparen
Institutioneller Zugang
Wie funktioniert Authentifizierung?
Haben Sie eine Idee, wie wir unsere Website verbessern können?
Bitte schreiben Sie uns.
© 2025 De Gruyter Brill
Heruntergeladen am 9.9.2025 von https://www.degruyterbrill.com/document/doi/10.1515/cdbme-2016-0127/html
Button zum nach oben scrollen