Several frequency bands have been identified for research and commercialization of BAN communication systems, such as the 402–405 MHz MedicalImplant Communication Services (MICS) band , the 2.4–2.48 GHz industrial, scientific, and medical (ISM) band , the 3.1–10.76 GHz ultra-wide band (UWB) range , and others. More recently, a new medical BAN (MBAN) band, which operates from 2.36 to 2.4 GHz, has been considered by the Federal Communication Commission (FCC) for its clean spectrum and low interference sources .
Abstract: Feasibility studies have been carried out for development of a biocompatible coating of medicalimplant materials allowing the binding of biodegradable drug-delivery systems in a way that their reloading might be possible. These novel coatings, able to bind biodegradable nanoparticles, may serve in the long run as drug carriers to mediate local pharmacological activity. After biodegradation of the nanoparticles, the binding sites could be reloaded with fresh drug-delivering particles. As a suitable receptor system for the nanoparticles, antibodies are anchored. The design of the receptor is of great importance as any bio- or chemorecognitive interaction with other components circulating in the blood has to be avoided. Furthermore, the binding between receptor and the particles has to be strong enough to keep them tightly bound during their lifetime, but on the other hand allow reloading after final degradation of the particles. The nanoparticles suggested as a drug-delivery system for medical implants can be loaded with different pharmaceuticals such as antibiotics, growth factors, or immunosuppressives. This concept may enable the changing of medication, even after implantation of the medical device, if afforded by patients’ needs.
reducing or eliminating allergic reactions, these materials also eliminate artifacs during post operative examination by traditional techniques such as X-ray, CT and MRI technology. Non-metallic materials also resist corrosion, leading to a longer implant life span. Polymers are also less dense than metals, have lower thermal conductivity and, in areas close to the translucent skin surface, provide better color aesthetics. In addition, oplymers present the ability to be surface modified with such coatings as hydroxyapatite or titanium, to aid secondary fixation or with chemical species as with bone morphogenic proteins (BMPs). Processing for some plastics can be easily scaled up to meet the increasing demand for product parts. Incorporating plastic technologies (for example, injection molding) means that the economics of production are viable on a larger scale, while complex shapes can be formed as required to aid device fabrication. However, often for prototype designs or shor production runs, it is not
Human being is interested to live for more years. In this connection medical field in thirst to innovate and introduce new technique to increase the life time. Techno economics and the comfort ability are the important factors that will push the medical sector to provide space for new entities from all the fields. Textile is one of the versatile fields to introduce new innovative products in all aspects. Medical textile provides opportunities to use textiles in new areas. This review says that superior textile materials in the form of fibre, yarn etc., have been utilized for application where bio compatibility and strength are required and will clearly bring a new and improved cluster of medical implantable devices. As it is an inter- disciplinary field, collaboration between medical and textile technocrats is the need of hour. Pancreas, myocardium, bone and other replacements need more developments.
Among many choices of alternative materials for infection treatment or prevention, silver captures much attention due to its broad-spectrum antimicrobial activity and lower propensity to induce bacterial resistance than antibiotics . Silver and its compounds have been used in medicine for decades as components of wound dressings, external skin treatments, debridement agents and eye medicines . The use of silver in coatings currently spans from central venous catheters to urinary tract catheters and coated orthopaedic implants  . While the exact mechanism by which silver demonstrates its efficacy is still under investigation, it is widely accepted that the antimicrobial effect is due to its ionic form . In most existing silver-based antimicrobial products, the silver ions are passively diffused from the incorporated surface layer . It has been found through in vivo animal models and clinical experiences that medical prostheses coated with silver alone do not necessarily demonstrate a discernible antimicrobial effect . Thus the slow silver ion release rate becomes the major bottleneck of antimicrobial efficacy for most existing silver medical implants.
It was around August 2012 when I started the Master’s education in Embedded systems at the University of Twente. I am always fascinated about wireless sensor networks, which is a part of embedded systems and is also widely applied in different industries for different scenarios. In this regard, I was fortunate to get introduced to Prof. Paul Havinga, by Ir. Andrea Sanchez Ramirez, during one of my courses called ”Energy efficient embedded systems”. Based on my work in EEES course, I was given an opportunity to work as a student assistant in an EU-FP7 project ”WiBRATE”, which involves application of WSN in industrial vibration monitoring. I continued working in the project for my intern-ship and also was given an opportunity to extend the work as a part-time job during my thesis. It was during this tenure as a student assistant I was supervised and guided by Dr. Niravana Meratnia. With highly constructive comments and progressive meetings together with Dr. Paul and Dr. Nirvana, I successfully proposed my idea of research about in-body sensor networks and continued with this thesis work. Although the assistantship work was not related to my thesis, I was given an opportunity to explore my own research interests. With their support, I was able to publish two international articles during my master study and of course a trip to Singapore for presentation. I was able to successfully complete this thesis overcoming all the difficulties. Even though this master thesis is just an exploration and characterization of existing wireless communication mechanisms, I hope with further research I can materialize the closed loop architecture for medical devices. I thank my professors for giving me another opportunity to continue with my research towards a PhD degree. I must thank Dr. Niels Moseley for his continuous and valuable technical support and Dr. Berend Jan van der Zwaag, for his constructive feedback at my writing skills. I thank Ir. Kyle zhang who developed the medical implants which were also used for the final hardware char- acterization in this thesis. I thank Ir. Saeid Yazdani for all his support in debugging codes at times. Apart from being thanked, I must acknowledge them for being excellent colleagues for the last one year. I also thank all the people of PS for making me feel comfortable at the office. I thank my friends, Alex, Frank, Yoppy, Gebremedhin, Anantha, Hasib, Anand, Nolie, Ramesh, Morshed, for being with me at difficult times. Apologies, for not having a whole list of names. I thank all of my friends who supported me either directly or indirectly during my master studies. Without all their support, staying far away from home and focusing on studies would not have been possible
Potential biomedical applications of silicon elastomer were studied by fabricating a very small capsule shaped implant containing thyroid hormone powder which released the hormone steadily for long time when tested in-vitro. Similar result was obtained with isoproterenol, digitoxin EDTA etc. When encapsulated in silicon 2 capsules. Power (1965) reported the use of silicon containing pyrimethamine to protect chicks from malaria. Use of silicon implants in veterinary medicine for contraception received much attention with the finding by DZINK & COOK. The slow release progesterone over one year period from silicon capsules were lately extended to the control released device for long term contraceptive activity.
An implant success rate is a numerical quantitative expression, which values the success of the implant as a matter of persistence until its fatal loss. This rate reaches 95% and is based on the osseointegration of the implant . If the osseointegration does not occur, the implant will be rejected and will not have a successful outcome because of early complications. There are two types of failures: early complication, which occur before the prosthetics and late complications after osseointegration and restoration [2,4-8]. It means that all 95% of successful implants still have risks of late failures, which are related with longevity and quality of treatment. Under functional loading condition physiologically we can expect 1 - 1.5 mm bone loss throughout the first year and < 0.2 mm every following year [8,9]. This process could be accelerated by mechanical, chemical and biological factors. With lack of attention and control, this physiological process may turn into a pathological inflammation of peri-implant soft tissues as peri- implant mucositis or its later form: peri-implantitis. Despite high implant survival rate, epidemiological studies and clinicians insufficiently paying attention to the quality factor and sustainability of our final restoration. However, there should be understood that implants cannot sufficiently replace natural teeth despite their survival rates .
The goal of tertiary reconstruction is the complete restoration of the breast after a failed previous recon- struction; it can be achieved with an implant, autolo- gous tissue, or a combination of both. Long-term implant-based reconstruction complications and im- provement on microvascular techniques are making patients ask for autologous reconstruction more often [16, 24]. In 1994, Feng et al. reported the use of au- togenous tissue for breast reconstruction following implant failure ; nowadays, there are several au- tologous flaps used for this purpose, such as deep in- ferior epigastric artery perforator flap (DIEP), superior gluteal artery perforator flap (SGAP), transverse mus- culocutaneous gracilis flap (TMG), superficial inferior epigastric artery perforator flap (SIEA), and many others . These procedures have the advantage of resulting in a breast that responds to weight changes, that has a natural texture, and that eliminates the risk of capsular contracture, but they require certain microsurgical expertise, lead to additional scars in the donor site, and need longer surgeries than their prosthetic-based counterparts [18, 26, 27].
As shown in the meta-analysis, no significant differ- ences were observed regarding implant success rate and implant stability (measured at days 0 and 10, and at 3, 4, 6, 12 weeks) between the PBMT group and control group. As for the other two studies, which were ex- cluded from meta-anaysis, Memarian et al. used PTV and reported significant improvement in implant stabil- ity 3 and 4 weeks after treatment with LED or low level laser when compared with control group. Abohabib et al. used RFA in Hertz and also observed a significant in- crease in implant stability in the PBMT group compared with control group after 3 to 10 weeks. Although in ani- mal studies it was established that PBMT increased bone-implant contact, and improved the production of OPG and RANKL without negative effects on bone re- sorption , existing clinical data did not provide suffi- cient evidence that PBMT has a positive effect on implant stability or success rate in humans. Herein, we have several hypotheses to explain the insignificant ef- fects of PBMT on humans, which was inconsistent with the data presented in animal studies.
Taper angle of implant is one of the important considerations in stress distribution around implant area. Tsuyoshi kitagawa et al found in their study that equivalent von mises stress distribution decreases with increase in taper angle of implant. Fig.2 shows that minimum stress occurs for implant having maximum taper angle. But Maitath et al reported that implant having zero taper angle i.e. cylindrical implant produces more desirable stress profile around implant surface than conical implant having certain degree of taper angle . Survival rate of implant inserted in soft quality bone is less than that of implant inserted in good quality bone. Hence there is a need for taper implant .
We studied the relationship between osteolysis and polyethylene wear, age at surgery, body mass index and height in 463 subjects (180 osteolysis and 283 controls) after cemented Charnley total hip arthroplasty (THA), in order to develop a kernel-based Bayesian model to quantitate risk of osteolysis. Such tools may be integrated into decision-making algorithms to help personalize clinical decision-making. A predictive model was constructed, and the esti- mated posterior probability of the implant failure calculated. Annual wear provided the greatest discriminatory information. Age at surgery provided additional predictive information and was added to the model. Body mass index and height did not contain valuable discriminatory information over the range in which observations were densely sampled. The robustness and misclassification rate of the predictive model was evaluated by a five-times cross-validation method. This yielded a 70% correct predictive classification of subjects into osteolysis versus non-osteolysis groups at a mean of 11 years after THA. Finally, the data were divided into male and female subsets to further explore the relationship between wear rate, age at surgery and inci- dence of osteolysis. The correct classification rate using age and wear rate in the model was approximately 66% for males and 74% for females.
Results from an experimental heat conduction model investigating the ranges of temperature gradients occur- ring in implants demonstrate that a 60°C heat source causes a heat front exceeding 47°C and advances more than 3 mm down an implant within 1 s . Tempera- tures over 47°C for more than a minute cause necrosis of cortical bone [23-25]. Some studies investigating the potential harmfulness of intraoral abutment preparation or plaster on implants to osseointegration mention this threshold as harmful [26-28]. It has been postulated that a rise in temperature to 42°C causes denaturation of osteoblasts and should be considered the temperature threshold of transient changes in bone . This thresh- old was used by others when investigating the potentially damaging effect to the implant-bone interface as a result of drinking hot beverages [29-31]. Also from endodontic literature regarding the removal of metal endodontic posts, concerns have been raised based on observations from in vitro experiments with respect to potentially detrimental heat transformation through dentine while ultrasonically manipulating the post [32-37].
cells trapping, and epithelialization which helps in wound healing which are postulated as promoters of tissue regeneration (Kim, Tae-Hoon et al., 2014). These platelet concentrates have been previously tested around dental implants and have been demonstrated to have an osteoregenerative effect on peri-implant bonebecause of their pro-angiogenic effects and enhancing the differentiating effects on osteoblasts. Demineralized freeze-dried bone graft (DFDBG) is the commonly used allograft which has both osteoinductive and osteoconductive potential and also overcome the drawbacks of autogenous graft materials like longer surgical procedure and morbidity in the donator site 7 . In particular, grafting materials mixed with platelet concentrates (PRP and PRF) has been reported to enhance the osseointegration and particularly favors the physiologic architecture to support the healing process around implants, leading to good quantity and quality of bone formation in peri- implant defects which in turn helps in the long term success of the implant in the rehabilitation of severe functional, anatomical or aesthetic problems arising from tooth loss. Thusthe present experimental study was therefore designed for evaluating the efficiency of platelet rich plasma and platelet rich fibrin in combination with Demineralized freeze-dried bone graft in a peri-implant bone defect.
All patients from the Department for Oral, Cranio- Maxillofacial and Facial Plastic Surgery, Medical Center of Goethe University Frankfurt who received implants of 7-mm length in the posterior maxilla to avoid a sinus augmentation procedure within the past 7 years were screened. Furthermore, the implants had to be loaded for at least 2 years. The initial residual bone height varied be- tween 6 and 8 mm, leading to a bicortical fixation of the implants. The kind of prosthetic restoration (removable/ fixed, splinted/un-splinted) was not defined as an inclusion/ exclusion criteria. Patients with incomplete data collection and those who refused to participate in the study were ex- cluded. A total of 17 patients met the inclusion criteria, 14
Page 60 of 86 The first materials selection map on the top of figure 4.1b compares modulus and density of different types of bone and the common used materials. It can be seen clearly that steels have the highest Young’s modulus and much higher than that of bone. This means that stress shielding will be a serious issue if choosing steels for designing femoral components. The American Iron and Steel Institute (AISI) type 316L is the primary stainless steel that is currently recommended for manufacturing implant devices (Newton and Nunamaker 1985). Many studies including Manivasagam, Dhinasekaran and Rajamanickam (2010), Hornberger, Virtanen, and Boccaccini (2012) and Raval and Choubey (2005) have shown a concern about the biocompatibility of 316L stainless steel and its corrosion resistance in vivo. Even though stainless steels are highly resistant to corrosion in nature, but localized corrosion can be found in these alloys when using in certain environment such as human body. These studties also mentioned that the corrosion products under corrosive attacks could be very harmful for humans. Aksakal, Yildirim and Gul (2004) reported that allergens such as cobalt, nickel, chrome and their compounds are found in stainless steel’s corrosion products. Morais et al. (1998, 1999) claimed that 316L stainless steel releases toxic corrosion products to osteogenic cells. The differentiation and proliferation of these cells are also affected. Beyond a certain concentration of this may disturb the normal behavior of marrow cell culture.
The implants used in this study were newly developed parabolic screw-type implants (ILI) with a length of 10 mm and a diameter of 4.1 mm at the shoulder of the implant (Fig 1). The implants were made of pure titanium with a characteristic progressive thread design. The threads as well as the curvature of the implant provided a homogeneous strain distribution over the whole implant surface under vertical loading conditions (Fig 2), as revealed by finite element analysis . The implants pos- sess a microstructured texture of 20 – 30 µm deep grooves, where as the titanium surface it is smooth on a nanoscale level. The implant system consists of two parabolic burrs of different diameters and morphologies. The burrs are used subsequently to prepare the bony implantation bed. The diameter of the second burr is slightly smaller then the core diameter of the implant. Implants have a trans- versal core/thread relation of 1:1.2. Implant insertion is performed by manual tapping of the self cutting implants into the surgically created bony implantation bed. Experimental animals
Sinusitis can occur as a result of contamination of the maxillary sinus with oral flora in aseptic surgical condi- tions . Although iatrogenic small sinus membrane perforations during surgery does not seem to be related to the development of postoperative sinusitis in healthy patients, large perforations of the maxillary sinus mem- brane have a higher likelihood of resulting in a discharge of bony fragments into the maxillary sinus and leading to maxillary sinusitis. Other causes are: ostium obstruc- tion due to postoperative swelling of the maxillary mu- cosa, blockage of air flow due to diminished intrasinus volume, impaired mucosal activity in the maxillary sinus due to mucosal lacerations, and implant exposure and extensions [17-19].
and 85KV/5.5 mA/0.2 mm Voxel was performed to proceed with the detailed implant planning (Fig. 4). Based on the anatomical conditions and prosthetic planning (i.e. tooth setup for the provisional RPD), six implants were virtually planned (3Diagnosys, 3DIEMME, Cantu, Italy) in the FDI (Fédération Dentaire Internationale) positions 46, 44, 42, 33, 35, and 36. As the implant positions 42 and 33 inter- fered with the teeth 43 and 33, a two-step procedure with two surgical templates was planned for the guided implant placement (Fig. 5a, b). The templates were fabricated stereolithographically (DS3000, XFAB, DWS srl, Thiene, Italy) according to the virtual implant planning. Based on the same digital file (Fig. 6a, b) a provisional fixed dental prosthesis (FDP) was prepared preoperatively allowing for an intraoral adaptation between the abutments and the framework to achieve a passive fit (Fig. 7a-d).