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- Benca, E., et al.
(författare)
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Thermal Effects during Bone Preparation and Insertion of Osseointegrated Transfemoral Implants
- 2021
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 21:18
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Tidskriftsartikel (refereegranskat)abstract
- Background: The preparation of bone for the insertion of an osseointegrated transfemoral implant and the insertion process are performed at very low speeds in order to avoid thermal damages to bone tissue which may potentially jeopardize implant stability. The aim of this study was to quantify the temperature increase in the femur at different sites and insertion depths, relative to the final implant position during the stepwise implantation procedure. Methods: The procedure for installation of the osseointegrated implant was performed on 24 femoral specimens. In one specimen of each pair, the surgery was performed at the clinically practiced speed, while the speed was doubled in the contralateral specimen. Six 0.075 mm K fine gauge thermocouples (RS Components, Sorby, UK) were inserted into the specimen at a distance of 0.5 mm from the final implant surface, and six were inserted at a distance of 1.0 mm. Results: Drilling caused a temperature increase of <2.5 degrees C and was not statistically significantly different for most drill sizes (0.002 < p < 0.845). The mean increase in temperature during thread tapping and implant insertion was <5.0 degrees C, whereas the speed had an effect on the temperature increase during thread tapping. Conclusions: Drilling is the most time-consuming part of the surgery. Doubling the clinically practiced speed did not generate more heat during this step, suggesting the speed and thus the time- and cost-effectiveness of the procedure could be increased. The frequent withdrawal of the instruments and removal of the bone chips is beneficial to prevent temperature peaks, especially during thread tapping.
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- Farina, D., et al.
(författare)
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Toward higher-performance bionic limbs for wider clinical use
- 2021
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Ingår i: Nature Biomedical Engineering. - : Springer Science and Business Media LLC. - 2157-846X. ; 7:4, s. 473-85
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Tidskriftsartikel (refereegranskat)abstract
- Most prosthetic limbs can autonomously move with dexterity, yet they are not perceived by the user as belonging to their own body. Robotic limbs can convey information about the environment with higher precision than biological limbs, but their actual performance is substantially limited by current technologies for the interfacing of the robotic devices with the body and for transferring motor and sensory information bidirectionally between the prosthesis and the user. In this Perspective, we argue that direct skeletal attachment of bionic devices via osseointegration, the amplification of neural signals by targeted muscle innervation, improved prosthesis control via implanted muscle sensors and advanced algorithms, and the provision of sensory feedback by means of electrodes implanted in peripheral nerves, should all be leveraged towards the creation of a new generation of high-performance bionic limbs. These technologies have been clinically tested in humans, and alongside mechanical redesigns and adequate rehabilitation training should facilitate the wider clinical use of bionic limbs. This Perspective argues that technologies for the neural interfacing of robotic devices with the body that have been clinically tested in humans should be leveraged toward the creation of a new generation of high-performance bionic limbs.
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- Ortiz Catalan, Max Jair, 1982, et al.
(författare)
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Offline Accuracy: A Potentially Misleading Metric in Myoelectric Pattern Recognition for Prosthetic Control.
- 2015
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Ingår i: Proceedings of the 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC), Milan, Italy, 15-19 August 2015. - 1557-170X. - 9781424492718 ; , s. 1140-1143
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Konferensbidrag (refereegranskat)abstract
- Offline accuracy has been the preferred performance measure in myoelectric pattern recognition (MPR) for the prediction of motion volition. In this study, different metrics relating the fundamental binary prediction outcomes were analyzed. Our results indicate that global accuracy is biased by 1) the unbalanced number of possible true positive and negative outcomes, and 2) the almost perfect specificity and negative predicted value, which were consistently found across algorithms, topologies, and movements (individual and simultaneous). Therefore, class-specific accuracy is advisable instead. Additionally, we propose the use of precision (positive predictive value) and sensitivity (recall) as a complement to accuracy to better describe the discrimination capabilities of MPR algorithms, as these consider the effect of false predictions. However, all the studied offline metrics failed to predict real-time decoding, and therefore real-time testing continue to be necessary to truly evaluate the clinical usability of MPR.
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| 6. |
- Brånemark, Rickard, 1960, et al.
(författare)
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Bone response to laser-induced micro- and nano-size titanium surface features.
- 2011
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Ingår i: Nanomedicine : nanotechnology, biology, and medicine. - : Elsevier BV. - 1549-9642 .- 1549-9634.
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Tidskriftsartikel (refereegranskat)abstract
- The present study explored whether laser-induced, site-specific implant surface modifications with micro- and nano-scale topography were able to promote bone formation. The aim was to evaluate the biomechanical and histological response to partly laser-modified titanium implants compared with machined implants. After an early 8-week healing period in rabbit tibia and femur, a 250% increase in removal torque was demonstrated for the partly laser-modified surface. Further, different fracture mechanisms were demonstrated for the two surfaces. Histologically, significantly more bone was found in direct contact with the laser-modified surface for the implants in the tibia sites, while a similar amount of bone tissue was observed in contact with the implant in the femoral sites. In conclusion, an improved bone-implant interface anchorage was promoted by an increase in micro- and nano-scale implant surface topography and surface oxide induced by topological laser treatment.
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| 10. |
- Jarmar, T., et al.
(författare)
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Characterization of the surface properties of commercially available dental implants using scanning electron microscopy, focused ion beam, and high-resolution transmission electron microscopy
- 2008
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Ingår i: Clinical Implant Dentistry and Related Research. - : Wiley. - 1523-0899 .- 1708-8208. ; 10:1, s. 11-22
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Since osseointegration of the respective implant is claimed by all manufacturing companies, it is obvious that not just one specific surface profile including the chemistry controls bone apposition. PURPOSE: The purpose was to identify and separate out a particular set of surface features of the implant surfaces that can contribute as factors in the osseointegration process. MATERIAL AND METHODS: The surface properties of several commercially available dental implants were extensively studied using profilometry, scanning electron microscopy, and transmission electron microscopy. Ultrathin sections prepared with focused ion beam microscopy (FIB) provided microstructural and chemical data which have not previously been communicated. The implants were the Nobel Biocare TiUnite (Nobel Biocare AB, Goteborg, Sweden), Nobel Biocare Steri-Oss HA-coated (Nobel Biocare AB, Yorba Linda, CA, USA), Astra-Tech OsseoSpeed (Astra Tech AB, Molndal, Sweden), Straumann SLA (Straumann AG, Waldenburg, Switzerland), and the Branemark Integration Original Fixture implant (Branemark Integration, Goteborg, Sweden). RESULTS: It was found that their surface properties had differences. The surfaces were covered with crystalline TiO(2) (both anatase and rutile), amorphous titanium oxide, phosphorus doped amorphous titanium oxide, fluorine, titanium hydride, and hydroxyapatite, respectively. CONCLUSION: This indicates that the provision of osseointegration is not exclusively linked to a particular set of surface features if the implant surface character is a major factor in that process. The studied methodology provides an effective tool to also analyze the interface between implant and surrounding bone. This would be a natural next step in understanding the ultrastructure of the interface between bone and implants.
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