Home Medicine Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
Article Open Access

Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone

  • E. Mick EMAIL logo , H. Steinke , T. Wolfskämpf , J. Wieding , N. Hammer , M. Schulze , R. Souffrant and R. Bader
Published/Copyright: September 12, 2015

Abstract

Bone specimens obtained for biomechanical experiments are fresh-frozen for storage to slow down tissue degradation and autolysis in long-term storage. Alternatively, due to infectious risks related to the fresh tissues, fixative agents are commonly used. However, fixatives will likely change the mechanical properties of bone. Existing studies on this issue gave controversial results that are hardly comparable due to a variety of measurement approaches. For this reason, the influence of ethanol and a formalin-based fixative agent was evaluated on the mechanical properties of human cortical bone specimens by means of four-point-bending tests. 127 prismatic specimens with rectangular cross sections (2.5 x 2.5 x 20 mm3) were obtained from different regions of two fresh human femora (medial, lateral, dorsal, ventral). Specimens were either fixed in ethanol or in a mixed formalin solution or frozen following a given scheme. After two weeks of storage the samples were re-hydrated in isotonic saline and subsequently tested mechanically. The elastic bending modulus and ultimate bending strength were computed considering the actual dimensions of each specific specimen. For statistical analysis a one-way-ANOVA and an LSD post-hoc-test were performed. For ultimate bending strength no significant differences due to formalin or ethanol fixation, as compared to unfixed-fresh bone specimens could be found. And only for few cases significant differences in elastic bending modulus were observed when the two bones were evaluated separately. Since more differences of significant level due to the anatomical region of the samples were determined, the original location seems to have more influence on the evaluated mechanical properties than the method of (chemical) fixation. Consequently, ethanol and the mixed formalin solution can be recommended as a fixation agent for samples in biomechanical testing, if these samples are rinsed in isotonic saline prior to static mechanical testing.

1 Introduction

In biomechanics and biomedical engineering, mechanical tests and in-vitro experiments are required to obtain material properties or to validate numerical simulations. These experiments should be executed in an in-vivo-like environment. Bones and derived specimens are often stored in a frozen condition as a gold standard. This procedure has been proven to alter most of the mechanical properties of bony material to minor extent [13]. However, when dealing with fresh-frozen specimens, there is a potential infection risk for researchers being exposed to the tissues. Furthermore, it is nearly impossible to perform long-term tests with unfixed specimens due to the ongoing processes of tissue degradation and autolysis [4].

In order to minimize infectious risks and to enhance the durability of biological tissues, specimens are often fixed, using different chemical agents. There have been several attempts to investigate the influence of said fixatives on the mechanical properties of bone. However, there is still a lack of distinct findings due to the miscellaneous conditions under which most studies have been performed. Some research groups used human bones [1, 5, 6] while others carried out their tests with faunal bones [3, 610]. Furthermore either entire bones [3, 8, 10, 11] or machined specimens with uniform geometrical shape [1, 57, 9, 12, 13] were used in varying testing setups, including three- and four-point-bending, compression, tension and torsion tests. Accordingly, the results and conclusions drawn from these studies differ to large extent. Some authors reported substantial influences of fixation on the mechanical properties [9, 11] while others identified only slight effects [1, 58, 10, 12, 13] or even hardly any influence at all [3, 14].

The following experimental study was conducted to evaluate the influence of two different fixative agents on the mechanical properties of human femoral cortical bone. We hypothesize that there are differences between chemically unfixed specimens and those treated with ethanol or a mixed formalin solution. Our second hypothesis is that mechanical properties of bone are more dependent on the anatomical region than on the method of fixation.

2 Material and methods

2.1 Sample preparation and treatment

Bone samples were obtained from two right-sided human femora (F1/2) in the fresh condition. While alive, the body donors gave their informed consent to the donation of their bodies for research purposes after their passing. The femora were pre-cooled and subsequently shock-frozen at 80 °C for storage. Bone samples were taken from the ventral, dorsal, medial and lateral compacta with a diamond blade band saw BS270-S (DRAMET Draht und Metallbau GmbH, Kleinmaischeid, Germany). The dimensions of each sample were 2.5 by 2.5 mm and 20 mm along the femoral shaft axis. The resulting specimens were again stored at 80 °C and numbered in a sequence from proximal to distal.

Depending on the number of specimens obtained from every single (long) beam, the samples were fixed with chemical agents following a random scheme depicted in Figure 1. to ensure a proper statistical distribution. Two fixation fluids were used: technical ethanol (96 % by mass, Brenntag GmbH, Mühlheim, Germany) or a mixed fixation solution containing formalin, ethanol, distilled water, glycerin, thymol, and salicylic acid at given volumes of 5.5%, 60.7%, 24.8%, 8.3%, 0.5%, 0.4% and 0.3%, respectively (“Hauslösung” supplied by the Department of Anatomy of the University of Rostock). The corresponding 2 ml tubes were filled with the fixation fluid covering the entire bone specimen and a volume ratio between fixative and specimen of at least 10:1.The chemically fixed samples were stored at room temperature for 14 days, while the unfixed-fresh ones were stored in shock-frozen condition. Table 1 shows the distribution of fixed specimens for each bone. The frozen unfixed specimens were thawed and both the unfixed and the fixed specimens were rinsed in isotonic sodium chloride solution for at least 30 minutes to minimize a possible influence of dehydration [15] or to remove the fixatives prior to material testing. The intrinsic height and width of every single sample were obtained using a caliper.

Figure 1 Scheme of chemical fixation for different numbers of specimens per anatomical region; et ! ethanol; mf ! mixed formalin fixation; uf ! unfixed-fresh.
Figure 1

Scheme of chemical fixation for different numbers of specimens per anatomical region; et ! ethanol; mf ! mixed formalin fixation; uf ! unfixed-fresh.

Table 1

Quantities of bone specimens.

bonenumber obtainedethanolmixed fixationunfixed-fresh
F170241828
F257191523

2.2 Mechanical testing

All specimens underwent a four-point-bending test conducted in an electromechanical testing machine Zwicki-Line Z1.0 and a force sensor XforceP 1kN (both Zwick GmbH & Co. KG, Ulm, Germany; precision 4 N). The width S between the supports was set to 16 mm while the loading span L was 6 mm (Figure 2). After a dwell of 2 s at a preload of 2 N the sample was loaded at a crosshead speed of 1 mm/min until material failure occurred, indicated by a visible breaking of the sample into separate pieces or by a slow but steady decrease of force after a distinct maximum value.

Figure 2 Test setup indicating bearing loads, loading span L and support span S.
Figure 2

Test setup indicating bearing loads, loading span L and support span S.

The data were obtained and analyzed with testXpert II software (V3.4, Zwick GmbH & Co. KG, Ulm Germany). Further investigation of the data was processed with Excel 2007 (Microsoft Corporation, Redmond, WA, USA). For each specimen the load-displacement-diagram was analyzed and the corresponding linear slope (F / w ) was determined for the region of elastic material behavior. The regression should end up with a coefficient of determination higher than 0.995. Ultimate stress and elastic bending modulus were calculated based on the sample width b, height h and lever arm a = 5 mm by:

σmax=3Fabh2E=5.6ΔFΔwa31000bh3

Statistical analyses were performed using SPSS (V20, IBM Corp., Armonk, USA) via one-way-ANOVA followed by a LSD post-hoc-test. The level of significance was set to p < 0.050.

3 Results

The evaluation of all tested specimens without consideration of the anatomical region revealed values for ultimate bending strength of 175.0 ± 43.0 MPa (mean ±standard deviation) for (et), 175.1 ± 41.6 MPa for (mf) and 171.7 ± 40.0 MPa for (uf). The elastic bending modulus was determined as 8.7 ± 1.8 GPa (et), 9.2 ± 1.8 GPa (mf) and 9.1 ± 1.8 GPa (uf), respectively. Neither of them showed any differences of significant level (p > 0.05). Distinguishing between the two investigated bones led to similar results.

Evaluating a possible influence of the fixation method on the mechanical properties for each anatomical region separately revealed significant differences in elastic bending modulus between ethanol and mixed formalin (p = 0.047) and between ethanol and unfixed-fresh samples (p = 0.038) for the ventral region of F1 and between ethanol and unfixed-fresh (p = 0.035) for the lateral region of F2. Summarizing all samples of both bones showed no significant differences depending on the fixation method.

The evaluation of regional dependencies of mechanical properties within groups of equally treated specimens showed differences of significant level in ultimate bending strength between dorsal and ventral samples fixed with ethanol (p = 0.017) as well as with mixed formalin (p = 0.020) for F1. Furthermore, the ultimate bending strength differed significantly for unfixed-fresh samples from the medial and the lateral regions (p = 0.014) and from the lateral and the ventral regions (p = 0.041) of F2. When all samples were put together, a significant difference in ultimate bending strength was found for unfixed-fresh bone from the medial and the lateral regions (p = 0.009).

Within F1, he elastic bending modulus was found to differ significantly for unfixed-fresh samples from the medial and the ventral regions (p = 0.006), for samples fixed with ethanol from the lateral and the ventral regions (p = 0.024) as well as from the dorsal and the ventral regions (p = 0.030) and for samples treated with mixed formalin solution from the dorsal and the ventral regions (p = 0.049). For F2 a difference of significant level in elastic bending modulus was observed for unfixed-fresh samples from the lateral and the ventral regions (p = 0.036). When evaluating all tested specimens from both bones together, significant differences in elastic bending modulus between ethanol fixed bone from the medial and the ventral regions (p = 0.050) as well as from the lateral and the ventral regions (p = 0.008) and for unfixed-fresh specimens from the medial and the lateral regions (p = 0.033) were determined.

4 Discussion

The present study observed the influence of commonly used chemical fixatives on the on mechanical properties of unfixed rectangular bone specimens and to compare these data to region-dependent properties obtained from the specimens. Machined specimens were successfully tested in a four-point-bending test, enabling the examination of elastic bending modulus and ultimate bending strength in small specimen dimensions of a given geometrical shape and anatomical orientation.

As it is difficult to obtain, prepare and test fresh human tissues immediately after removal, the unfixed bone samples were temporarily shock frozen for storage. Though freezing the specimens for storage may be regarded as a gold standard due to minor effects on the mechanical properties of bones [13], other studies showed alterations of almost 30% in other tissues [16]. Furthermore, a possible influence on the mechanical properties due to the loss of water [15] was minimized by rinsing the specimens prior to mechanical testing.

Four-point-bending was accounted to be suitable as a test method because of the constant bending moment between the loading points. Furthermore, no transverse shear stresses are present like they are in a three-point-bending test around the middle section of the specimen [17]. However this method requires the force to be equal at both loading points, which is quite difficult to accomplish when the entire bone is tested. Nevertheless, entire bones are often used in experimental setups and they might be easier to handle. However, using entire bones, only extrinsic properties and the overall behavior of the bone can be calculated with the widely applied techniques of tensile or compressive material testing. The further deduction of intrinsic mechanical properties remains very challenging, since the geometrical shape of each bone varies inter-individually and possibly age-dependently. Therefore, a precise reassembly of entire bony material properties is quite time-consuming and due to the shape irregularities a large amount of samples is required to make reliable statistical predictions. Here, machined specimens at a pre-defined size are advantageous.

Given the large amount of different donor species, testing conditions and fixation media, the results of most studies are hard to compare. Our results are quite similar to the data of van Haaren et al. [3], who also found minor and non-significant differences in bending strength in unfixed and formaldehyde-fixed entire bone specimens from goats. However, using faunal bones to derive conclusions for the human locomotive system remains critical, since there are species- and geometry-dependent material properties of cortical bone [18]. Therefore, the most reliable data has to be derived from human bone tissues.

In summary, the possible influence of different fixatives on the mechanical properties of human cortical bone specimens was examined under standardized and reproducible testing conditions. The lack of significant differences between unfixed-fresh, ethanol- and mixed-formalin-fixed bone specimens suggests that the given fixation agents can be used in the short-term, if data close to the native situation is of interest and if the samples are sufficiently rinsed in isotonic saline prior to the material testing.

In conclusion, we see our first hypothesis disproved since no significant differences comparing the three fixation methods could be determined. On the other hand, our investigations corroborated the second hypothesis that mechanical properties bone depend on the anatomical region of the specific samples.

In further investigations the duration of fixation should be extended to examine possible long-term effects. Moreover, the influence of fixative solutions on the mechanical properties of cancellous bone might be of interest.

Author's Statement

  1. 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 research related to human use has been complied with all the relevant national regulations, institutional policies and in accordance the tenets of the Helsinki Declaration, and has been approved by the authors’ institutional review board or equivalent committee.

References

[1] Linde F et al. The Effect of Different Storage Methods on the Mechanical Properties of Trabecular Bone. J Biomech 1993, 26, 1249-125210.1016/0021-9290(93)90072-MSearch in Google Scholar

[2] Kaye B et al. The Effects of Freezing on the Mechanical Properties of Bone. Open Bone J 2012, 4, 14-1910.2174/1876525401204010014Search in Google Scholar

[3] van Haaren EH et al. Effect of Long-Term Preservation on the Mechanical Properties of Cortical Bone in Goats. Acta Orthop 2008, 79, 708-71610.1080/17453670810016759Search in Google Scholar

[4] Öhman C et al. The Effects of Embalming Using a 4% Formalin Solution on the Compressive Mechanical Properties of Human Cortical Bone. Clin Biomech (Bristol, Avon) 2008, 23, 1294-129810.1016/j.clinbiomech.2008.07.007Search in Google Scholar

[5] Burkhart KJ et al. Influence of Formalin Fixation on the Biomechanical Properties of Human Diaphyseal Bone. Biomed Tech (Berl) 2010, 55, 361-36510.1515/bmt.2010.043Search in Google Scholar

[6] Unger S et al. Effects of Three Different Preservation Methods on the Mechanical Properties of Human and Bovine Cortical Bone. Bone 2010, 47, 1048-105310.1016/j.bone.2010.08.012Search in Google Scholar

[7] Currey JD et al. Effect of Formaldehyde Fixation on Some Mechanical Properties of Bovine Bone. Biomaterials 1995, 16, 1267-127110.1016/0142-9612(95)98135-2Search in Google Scholar

[8] Edmondston SJ et al. Formalin Fixation Effects on Vertebral Bone Density and Failure Mechanics: an in-Vitro Study of Human and Sheep Vertebrae. Clin Biomech 1994, 9, 175-17910.1016/0268-0033(94)90018-3Search in Google Scholar

[9] Kikugawa H et al. Effect of Long-Term Formalin Preservation on Bending Properties and Fracture Toughness of Bovine Compact Bone. Mater Trans 2004, 45, 3060-306410.2320/matertrans.45.3060Search in Google Scholar

[10] Nazarian A et al. Effects of Tissue Preservation on Murine Bone Mechanical Properties. J Biomech 2009, 42, 82-8610.1016/j.jbiomech.2008.09.037Search in Google Scholar PubMed

[11] Goh JC et al. Effect of Preservation Medium on the Mechanical Properties of Cat Bones. Acta Orthop Scand 1989, 60, 465-46710.3109/17453678909149321Search in Google Scholar

[12] McElhaney J et al. Effect of Embalming on the Mechanical Properties of Beef Bone. J Appl Physiol 1964, 19, 1234-123610.1152/jappl.1964.19.6.1234Search in Google Scholar

[13] Öhman C et al. The Effects of Embalming on the Compressive Mechanical Properties of Human Cortical Bone. J Biomech 2008, 41, S33710.1016/S0021-9290(08)70336-1Search in Google Scholar

[14] Beaupied H et al. The Mode of Bone Conservation Does Not Affect the Architecture and the Tensile Properties of Rat Femurs. Biomed Mater Eng 2006, 16, 253-25910.1177/09592989200601600401021Search in Google Scholar

[15] Nyman JS et al. The Influence of Water Removal on the Strength and Toughness of Cortical Bone. J Biomech 2006, 39, 931-93810.1016/j.jbiomech.2005.01.012Search in Google Scholar PubMed PubMed Central

[16] Gottsauner-Wolf F et al. Effects of Freeze/Thaw Conditioning on the Tensile Properties and Failure Mode of Bone-Muscle-Bone Units: A Biomechanical and Histological Study in Dogs. J Orthop Res 1995, 13, 90-9510.1002/jor.1100130114Search in Google Scholar PubMed

[17] Athanasiou KA et al. Fundamentals of Biomechanics in Tissue Engineering of Bone. Tissue Eng A 2000, 6, 361-38110.1089/107632700418083Search in Google Scholar PubMed

[18] Wang X et al. An Interspecies Comparison of Bone Fracture Properties. Biomed Mater Eng 1998, 8, 1Search in Google Scholar

Published Online: 2015-9-12
Published in Print: 2015-9-1

© 2015 by Walter de Gruyter GmbH, Berlin/Boston

This article is distributed under the terms of the Creative Commons Attribution Non-Commercial License, which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Articles in the same Issue

  1. Research Article
  2. Development and characterization of superparamagnetic coatings
  3. Research Article
  4. The development of an experimental setup to measure acousto-electric interaction signal
  5. Research Article
  6. Stability analysis of ferrofluids
  7. Research Article
  8. Investigation of endothelial growth using a sensors-integrated microfluidic system to simulate physiological barriers
  9. Research Article
  10. Energy harvesting for active implants: powering a ruminal pH-monitoring system
  11. Research Article
  12. New type of fluxgate magnetometer for the heart’s magnetic fields detection
  13. Research Article
  14. Field mapping of ballistic pressure pulse sources
  15. Research Article
  16. Development of a new homecare sleep monitor using body sounds and motion tracking
  17. Research Article
  18. Noise properties of textile, capacitive EEG electrodes
  19. Research Article
  20. Detecting phase singularities and rotor center trajectories based on the Hilbert transform of intraatrial electrograms in an atrial voxel model
  21. Research Article
  22. Spike sorting: the overlapping spikes challenge
  23. Research Article
  24. Separating the effect of respiration from the heart rate variability for cases of constant harmonic breathing
  25. Research Article
  26. Locating regions of arrhythmogenic substrate by analyzing the duration of triggered atrial activities
  27. Research Article
  28. Combining different ECG derived respiration tracking methods to create an optimal reconstruction of the breathing pattern
  29. Research Article
  30. Atrial and ventricular signal averaging electrocardiography in pacemaker and cardiac resynchronization therapy
  31. Research Article
  32. Estimation of a respiratory signal from a single-lead ECG using the 4th order central moments
  33. Research Article
  34. Compressed sensing of multi-lead ECG signals by compressive multiplexing
  35. Research Article
  36. Heart rate monitoring in ultra-high-field MRI using frequency information obtained from video signals of the human skin compared to electrocardiography and pulse oximetry
  37. Research Article
  38. Synchronization in wireless biomedical-sensor networks with Bluetooth Low Energy
  39. Research Article
  40. Automated classification of stages of anaesthesia by populations of evolutionary optimized fuzzy rules
  41. Research Article
  42. Effects of sampling rate on automated fatigue recognition in surface EMG signals
  43. Research Article
  44. Closed-loop transcranial alternating current stimulation of slow oscillations
  45. Research Article
  46. Cardiac index in atrio- and interventricular delay optimized cardiac resynchronization therapy and cardiac contractility modulation
  47. Research Article
  48. The role of expert evaluation for microsleep detection
  49. Research Article
  50. The impact of baseline wander removal techniques on the ST segment in simulated ischemic 12-lead ECGs
  51. Research Article
  52. Metal artifact reduction by projection replacements and non-local prior image integration
  53. Research Article
  54. A novel coaxial nozzle for in-process adjustment of electrospun scaffolds’ fiber diameter
  55. Research Article
  56. Processing of membranes for oxygenation using the Bellhouse-effect
  57. Research Article
  58. Inkjet printing of viable human dental follicle stem cells
  59. Research Article
  60. The use of an icebindingprotein out of the snowflea Hypogastrura harveyi as a cryoprotectant in the cryopreservation of mesenchymal stem cells
  61. Research Article
  62. New NIR spectroscopy based method to determine ischemia in vivo in liver – a first study on rats
  63. Research Article
  64. QRS and QT ventricular conduction times and permanent pacemaker therapy after transcatheter aortic valve implantation
  65. Research Article
  66. Adopting oculopressure tonometry as a transient in vivo rabbit glaucoma model
  67. Research Article
  68. Next-generation vision testing: the quick CSF
  69. Research Article
  70. Improving tactile sensation in laparoscopic surgery by overcoming size restrictions
  71. Research Article
  72. Design and control of a 3-DOF hydraulic driven surgical instrument
  73. Research Article
  74. Evaluation of endourological tools to improve the diagnosis and therapy of ureteral tumors – from model development to clinical application
  75. Research Article
  76. Frequency based assessment of surgical activities
  77. Research Article
  78. “Hands free for intervention”, a new approach for transoral endoscopic surgery
  79. Research Article
  80. Pseudo-haptic feedback in medical teleoperation
  81. Research Article
  82. Feasibility of interactive gesture control of a robotic microscope
  83. Research Article
  84. Towards structuring contextual information for workflow-driven surgical assistance functionalities
  85. Research Article
  86. Towards a framework for standardized semantic workflow modeling and management in the surgical domain
  87. Research Article
  88. Closed-loop approach for situation awareness of medical devices and operating room infrastructure
  89. Research Article
  90. Kinect based physiotherapy system for home use
  91. Research Article
  92. Evaluating the microsoft kinect skeleton joint tracking as a tool for home-based physiotherapy
  93. Research Article
  94. Integrating multimodal information for intraoperative assistance in neurosurgery
  95. Research Article
  96. Respiratory motion tracking using Microsoft’s Kinect v2 camera
  97. Research Article
  98. Using smart glasses for ultrasound diagnostics
  99. Research Article
  100. Measurement of needle susceptibility artifacts in magnetic resonance images
  101. Research Article
  102. Dimensionality reduction of medical image descriptors for multimodal image registration
  103. Research Article
  104. Experimental evaluation of different weighting schemes in magnetic particle imaging reconstruction
  105. Research Article
  106. Evaluation of CT capability for the detection of thin bone structures
  107. Research Article
  108. Towards contactless optical coherence elastography with acoustic tissue excitation
  109. Research Article
  110. Development and implementation of algorithms for automatic and robust measurement of the 2D:4D digit ratio using image data
  111. Research Article
  112. Automated high-throughput analysis of B cell spreading on immobilized antibodies with whole slide imaging
  113. Research Article
  114. Tissue segmentation from head MRI: a ground truth validation for feature-enhanced tracking
  115. Research Article
  116. Video tracking of swimming rodents on a reflective water surface
  117. Research Article
  118. MR imaging of model drug distribution in simulated vitreous
  119. Research Article
  120. Studying the extracellular contribution to the double wave vector diffusion-weighted signal
  121. Research Article
  122. Artifacts in field free line magnetic particle imaging in the presence of inhomogeneous and nonlinear magnetic fields
  123. Research Article
  124. Introducing a frequency-tunable magnetic particle spectrometer
  125. Research Article
  126. Imaging of aortic valve dynamics in 4D OCT
  127. Research Article
  128. Intravascular optical coherence tomography (OCT) as an additional tool for the assessment of stent structures
  129. Research Article
  130. Simple concept for a wide-field lensless digital holographic microscope using a laser diode
  131. Research Article
  132. Intraoperative identification of somato-sensory brain areas using optical imaging and standard RGB camera equipment – a feasibility study
  133. Research Article
  134. Respiratory surface motion measurement by Microsoft Kinect
  135. Research Article
  136. Improving image quality in EIT imaging by measurement of thorax excursion
  137. Research Article
  138. A clustering based dual model framework for EIT imaging: first experimental results
  139. Research Article
  140. Three-dimensional anisotropic regularization for limited angle tomography
  141. Research Article
  142. GPU-based real-time generation of large ultrasound volumes from freehand 3D sweeps
  143. Research Article
  144. Experimental computer tomograph
  145. Research Article
  146. US-tracked steered FUS in a respiratory ex vivo ovine liver phantom
  147. Research Article
  148. Contribution of brownian rotation and particle assembly polarisation to the particle response in magnetic particle spectrometry
  149. Research Article
  150. Preliminary investigations of magnetic modulated nanoparticles for microwave breast cancer detection
  151. Research Article
  152. Construction of a device for magnetic separation of superparamagnetic iron oxide nanoparticles
  153. Research Article
  154. An IHE-conform telecooperation platform supporting the treatment of dementia patients
  155. Research Article
  156. Automated respiratory therapy system based on the ARDSNet protocol with systemic perfusion control
  157. Research Article
  158. Identification of surgical instruments using UHF-RFID technology
  159. Research Article
  160. A generic concept for the development of model-guided clinical decision support systems
  161. Research Article
  162. Evaluation of local alterations in femoral bone mineral density measured via quantitative CT
  163. Research Article
  164. Creating 3D gelatin phantoms for experimental evaluation in biomedicine
  165. Research Article
  166. Influence of short-term fixation with mixed formalin or ethanol solution on the mechanical properties of human cortical bone
  167. Research Article
  168. Analysis of the release kinetics of surface-bound proteins via laser-induced fluorescence
  169. Research Article
  170. Tomographic particle image velocimetry of a water-jet for low volume harvesting of fat tissue for regenerative medicine
  171. Research Article
  172. Wireless medical sensors – context, robustness and safety
  173. Research Article
  174. Sequences for real-time magnetic particle imaging
  175. Research Article
  176. Speckle-based off-axis holographic detection for non-contact photoacoustic tomography
  177. Research Article
  178. A machine learning approach for planning valve-sparing aortic root reconstruction
  179. Research Article
  180. An in-ear pulse wave velocity measurement system using heart sounds as time reference
  181. Research Article
  182. Measuring different oxygenation levels in a blood perfusion model simulating the human head using NIRS
  183. Research Article
  184. Multisegmental fusion of the lumbar spine a curse or a blessing?
  185. Research Article
  186. Numerical analysis of the biomechanical complications accompanying the total hip replacement with NANOS-Prosthetic: bone remodelling and prosthesis migration
  187. Research Article
  188. A muscle model for hybrid muscle activation
  189. Research Article
  190. Mathematical, numerical and in-vitro investigation of cooling performance of an intra-carotid catheter for selective brain hypothermia
  191. Research Article
  192. An ideally parameterized unscented Kalman filter for the inverse problem of electrocardiography
  193. Research Article
  194. Interactive visualization of cardiac anatomy and atrial excitation for medical diagnosis and research
  195. Research Article
  196. Virtualizing clinical cases of atrial flutter in a fast marching simulation including conduction velocity and ablation scars
  197. Research Article
  198. Mesh structure-independent modeling of patient-specific atrial fiber orientation
  199. Research Article
  200. Accelerating mono-domain cardiac electrophysiology simulations using OpenCL
  201. Research Article
  202. Understanding the cellular mode of action of vernakalant using a computational model: answers and new questions
  203. Research Article
  204. A java based simulator with user interface to simulate ventilated patients
  205. Research Article
  206. Evaluation of an algorithm to choose between competing models of respiratory mechanics
  207. Research Article
  208. Numerical simulation of low-pulsation gerotor pumps for use in the pharmaceutical industry and in biomedicine
  209. Research Article
  210. Numerical and experimental flow analysis in centifluidic systems for rapid allergy screening tests
  211. Research Article
  212. Biomechanical parameter determination of scaffold-free cartilage constructs (SFCCs) with the hyperelastic material models Yeoh, Ogden and Demiray
  213. Research Article
  214. FPGA controlled artificial vascular system
  215. Research Article
  216. Simulation based investigation of source-detector configurations for non-invasive fetal pulse oximetry
  217. Research Article
  218. Test setup for characterizing the efficacy of embolic protection devices
  219. Research Article
  220. Impact of electrode geometry on force generation during functional electrical stimulation
  221. Research Article
  222. 3D-based visual physical activity assessment of children
  223. Research Article
  224. Realtime assessment of foot orientation by Accelerometers and Gyroscopes
  225. Research Article
  226. Image based reconstruction for cystoscopy
  227. Research Article
  228. Image guided surgery innovation with graduate students - a new lecture format
  229. Research Article
  230. Multichannel FES parameterization for controlling foot motion in paretic gait
  231. Research Article
  232. Smartphone supported upper limb prosthesis
  233. Research Article
  234. Use of quantitative tremor evaluation to enhance target selection during deep brain stimulation surgery for essential tremor
  235. Research Article
  236. Evaluation of adhesion promoters for Parylene C on gold metallization
  237. Research Article
  238. The influence of metallic ions from CoCr28Mo6 on the osteogenic differentiation and cytokine release of human osteoblasts
  239. Research Article
  240. Increasing the visibility of thin NITINOL vascular implants
  241. Research Article
  242. Possible reasons for early artificial bone failure in biomechanical tests of ankle arthrodesis systems
  243. Research Article
  244. Development of a bending test procedure for the characterization of flexible ECoG electrode arrays
  245. Research Article
  246. Tubular manipulators: a new concept for intracochlear positioning of an auditory prosthesis
  247. Research Article
  248. Investigation of the dynamic diameter deformation of vascular stents during fatigue testing with radial loading
  249. Research Article
  250. Electrospun vascular grafts with anti-kinking properties
  251. Research Article
  252. Integration of temperature sensors in polyimide-based thin-film electrode arrays
  253. Research Article
  254. Use cases and usability challenges for head-mounted displays in healthcare
  255. Research Article
  256. Device- and service profiles for integrated or systems based on open standards
  257. Research Article
  258. Risk management for medical devices in research projects
  259. Research Article
  260. Simulation of varying femoral attachment sites of medial patellofemoral ligament using a musculoskeletal multi-body model
  261. Research Article
  262. Does enhancing consciousness for strategic planning processes support the effectiveness of problem-based learning concepts in biomedical education?
  263. Research Article
  264. SPIO processing in macrophages for MPI: The breast cancer MPI-SNLB-concept
  265. Research Article
  266. Numerical simulations of airflow in the human pharynx of OSAHS patients
Downloaded on 25.12.2025 from https://www.degruyterbrill.com/document/doi/10.1515/cdbme-2015-0083/html
Scroll to top button