The results of registration of stapedial reflex in a response to electrical stimuli are often used during the fitting process of cochlear implant. Usually, the most comfortable loudness (MCL) levels of the working program are higher than threshold levels of the stapedial reflex. It is interesting to look at the reflex from another point of view, namely, to investigate the stapedial reflex in response to acoustic stimuli of low, medium and high frequencies in a group of seven experienced children who had been using their speech processor for three or more years. It was found that threshold sound pressure levels of the reflex to sound stimuli are within a normal range. The reflex threshold levels were found to underestimate the behavioral MCL values and therefore should be used with caution during the first fitting sessions. *Correspondence to: Petrov SM, PE, St. Petersburg, Russia, Tel: +79117495446; E-mail: senn2001@mail.ru
Dark matter as a rather astronomical term is interpreted as a fundamental part of the structure of living systems. Its function is connected with the materialization and control of the concept of existence. Recent research suggests that it may not be qualitatively different matter, but only matter that has fallen out of the existing system of normal matter. It is thus a world analogous but unobservable by normal means of normal matter.
Medical implants are being used extensively in the treatment of many types of medical ailments. Approximately 20% of adults in the U.S. have received an implant of one type or another. The U.S. Department of Commerce states that the global market for medical devices in 2016 was $339.5 billion and predicted that it would grow to $435.8 billion by 2020. As with any man-made device, some of these implants will fail. This paper provides the fundamental knowledge required by engineering and biomechanical professionals in order to analyze why an implanted orthopedic device has failed mechanically; generally by fracture. The focus will be limited to the failure of metals that are used to fabricate orthopedic implanted devices. Information regarding the biocompatibility of various engineered materials and their interaction with tissues is also presented. *Correspondence to: David R Bosch, Forensic Engineering, Inc., 5001 North 50th Street, Suite 4, Phoenix, Arizona 85008, USA, E-mail: davidb@feiaz.com Received: March 07, 2020; Accepted: March 25, 2020; Published: March 30, 2020 Introduction Medical implants are one of the great scientific breakthroughs and represent a growing financial sector. McCloy [1], has reported that the world-wide medical implant market exceeds $200 billion. He estimates that about 20% of adults in the U.S. have received an implant of one type or another. These numbers are substantiated by the U.S. Department of Commerce [2], which states that the global market for medical devices in 2016 was $339.5 billion and predicted that it would grow to $435.8 billion by 2020. As with any man-made device, some of these implants will fail. The materials that comprise medical implants fail in many different ways for many different reasons. In the case of the failure of engineered materials used for implantable devices, knowledge about medicine, human biology, biomaterials, engineering and many other factors must generally be considered and investigated before any conclusions can been drawn regarding the root cause of the device failure. The primary factors that must be considered include, but are not limited to, manufacturability and manufacturing processing requirements, biocompatibility of the proposed material(s), device geometry, the in vivo and in vitro environmental factors, the normal anticipated and traumatic (if any) loading conditions, and the health and condition of the patient. After a failed implanted device is explanted (removed) from the patient, it must be subjected to appropriate examination and tests. Perhaps the most critically important testing in cases of mechanical failure is the macro and micro examination of the failed device surface features and fracture surfaces. By using a wide array of tools and techniques, the analysis can reveal important surface features along with physical and mechanical properties of the failed device in order to determine if the device properties are consistent with those specified by the device manufacturer and ultimately determine the root cause of failure. One of the more important analytical techniques regarding the failure of various devices is fractography. The evaluation of fracture surface features often allows the analyst to determine what if any additional tests and/or investigations are required to complete the failure analysis. For example, if fractography reveals that an explanted device has failed due to surface damage created during the surgical implantation procedure, then the termination of the investigation may be deemed appropriate. If not, then additional tools and techniques may be employed to further investigate the root cause of the failure. Discussions regarding the history and types of implants along with the challenges of the development of biocompatible materials and related considerations are also presented. These subjects are covered in order to give the reader context in which to view the application of the tools and techniques that are generally relied upon to determine the root cause of implant failures. Without this knowledge, it may be very difficult, if not impossible, to understand the changes that are necessary to avoid future failures, and/or assist in the assignment of liability. The U.S. Food and Drug Administration (FDA) defines medical implants as, “Devices or tissues that are placed inside or on the surface of the body.” Implants are often prosthetics intended to replace missing or damaged human body parts. Other type of implants deliver medication, monitor body functions, and/or provide support to organs and tissues that have been damaged or are failing due to natural causes. McIntyre [3] summarized research published by 24/7WallSt.com based on its examination of National Health Survey data, peer-reviewed journals, multiple professional physician services, and Securities and Exchange Commission (SEC) filings to complete a list of the most frequently implanted medical devices in the United States of America. The report contained data that included the number of procedures for Bosch D (2020) Review of the biomechanics, engineering design and forensic failure analysis of implantable medical devices Biol Eng Med, 2020 doi: 10.15761/BEM.1000179 Volume 5: 2-18 each of the top 11 implantable devices implanted each year, along with the total expenditure, average cost for each procedure and the major manufacturers for each device. The findings indicated that the most implanted medical device was artificial eye lens (2.582 million lenses). Following in descending order were ear tubes (715,000), coronary stents (560,000), artificial knee joints (543,000), metal screws, plates and rods (453,000), intra-uterine devices (425,000), spinal screws, rods and artificial spinal discs (413,000), breast implants (366,000), heart pacemakers (235,567) and artificial hips (230,000). The data and information for each device are summarized in Table 1. In the U.S.A., implants are considered to be medical devices and are regulated by the FDA under three classifications as defined in Title 21 CFR Part 860.3. The three classes (Class I, Class II and Class III) divide medical devices based on increasing risk to the user. Examples of each of the implant categories are discussed below. It is also noted that there are many ASTM and ISO standards that are applicable to medical implants, several of which are referenced herein. The ideal implant material is described as having the following characteristics: 1) chemically inert; 2) excellent wear resistance; 3) superior biocompatibility; 4) an appropriate modulus of elasticity; 5) high strength; 6) long fatigue life; 7) corrosion-proof; and 8) inexpensive. Orthopedic implants are used to alleviate problems with joints (e.g. hips, knees, fingers and toes, wrists and shoulders). They also are used to repair or treat bone fractures, scoliosis of the spine, osteoarthritis, spinal stenosis and pain. Implants can fail for several reasons, including improper implantation, material defects, design defects, and/or manufacturing defects. The following sections provide an overview of the engineering and biomechanical challenges associated with implantable devices. Orthopedic implants are used in fracture fixation through a process termed “open reduction – internal fixation” (i.e., ORIF). Most typically at present, these materials are metal alloys. The purpose of this surgical procedure is to enable the orthopedic surgeon to adequately stabilize the two ends of a fractured long bone or to bring many bone fragments from a comminuted fracture together in a stable fashion. For example, in some surgical procedures of the hand, an arthrodesis (bone fusion) is achieved by removing a proximal interphalangeal (PIP) joint and approximating the saw cut ends of the two bones together (proximal and middle phalanges) and securing them with a bone screw or dorsal finger surface metal plate over the proximal PIP joint at a desired arthrodesis PIP angle (see Case Study 1). In some spinal surgical procedures, metal plates are fixed to the anterior vertebral bodies in fusing functional spinal units in the cervical or lumbar spine; less frequently in the thoracic spine. Furthermore, in conjunction with hardware applied to anterior vertebral bodies, the posterior elements of vertebral structures may also be reinforced in a separate fusion procedure. Spinal pathology such as scoliosis (lateral curvature{s}) may also be treated by hardware such as Harrington or Luque rods that enable the physician to apply an apparatus, which will apply tension on one side of the spine and compression on the other in an effort to correct the deformity. Currently, there are many different implants available for the treatment of scoliosis. Implant systems differ depending upon patient indications [4]. Current joint replacements are not only being used for hips and knees but also for interphalangeal joints, ankles, shoulders (glenohumeral (GH) joints) and other joints. These joint replacements may be in response to acute trauma, but are more commonly implanted in cases of remote trauma or advancing osteoarthritis, and/ or chondromalacia with the advanced loss of joint articular cartilage. Whereas joint replacements in the past many times would fail within 5 to 10 years requiring revision, new knee and hip replacements may be expected to last 20 to 30 years. As implant materials and joint designs continue to improve, it is expected that the device life longevity will continue to increase. Case study 1 – Swan neck deformity repair
Background: We evaluated sensitivity of contact heat evoked potentials (CHEPs) compared with sympathetic skin response (SSR) and Toronto Clinical Scoring System (TCSS) in diabetic neuropathy (DN) at early stage and analyze the characteristics of small fibers injury. Methods: A case-control study was conducted in 100 DN patients and 50 controls. A peak stimulating temperature of 51 ℃ was applied to the mandibular region, region above the eyebrow, lower limb an forearm. CHEPs parameters were recorded by the C Z point. The SSR examination and TCSS were also performed. Results: There were significant differences in the median of the ratio of N-wave latency in mandibular region to that in region above the eyebrow between the DM group and controls (Z=-3.441, P=0.001). There were also significant differences in the median of the ratio of N wave amplitude in forearm to that in the lower limb between the DM group and controls (Z=-3.441, P<0.01). The latency of the DMN group was longer than that of the controls after stimulation of the mandibular region. When we stimulated the region above the eyebrow, lower limb and forearm at 51 ℃ , the DMN group exhibited lower N-P amplitude and more prolonged N wave latency compared to those in controls. On the other side, when the region above eyebrow and lower limb was stimulated, the SSRN group had lower N-P amplitude and more prolonged N wave latency compared to controls. Conclusion: Compared with TCSS and SSR, CHEPs had higher sensitivity in the detection of DN at early stage.
This paper examines the effects of Date palm oil as a bitumen modifier on the compressive strength of bitumen and hot mixed asphalt (HMA) pavement.Date palm oil contains anti-oxidant isomers that have the potential to enhance the performance and durability of bitumen.The compressive strength test of asphalt pavement mixed with Date palm oil was performed in accordance with British Standards BS 1881: Part 116: 1983.The cube specimens of asphalt pavement were manufactured mixing with 0%, 2.5%, 5%, 7.5%, and 10% of Date palm oil out of total sample mass.The experimental results suggested that Date palm oil as a bitumen modifier reduced the compressive strength of HMA pavement.The findings of this paper urge for further experiments to understand the effects of Date palm oil on the asphalt pavements under long-term traffic load, environment and surface drainage.
This study investigated the utility of computerized tomographic assisted biomodel fabrication in Australia, which was enlisted as an aid to undertake either the resection or reconstruction of elements of the maxillofacial skeleton.The study sample was derived from the in-house database held by Anatomics® in relation to the patient cohort referred to them for maxillofacial biomodel fabrication.The primary predictor variable was the biomodel construct.The secondary outcome variables were the range and various applications that the biomodel engendered within the requesting surgical community.Other variables included the requesting surgical subspecialty.The study identified a total of 956 requests made by specialist surgeons which resulted in biomodel construction.The biomodels were fabricated in a range of facial anatomical combinations or as individual subsites.Biomodel applications included surgical simulation, mirror imaging, pre-bending of internal fixation reconstruction plates, the provision of implant positioning/fabricating templates and cutting guides and the production of PoreStar® porous polyethylene implants fabricated for contour reconstruction.The requests predominantly came from the discipline of Oral and Maxillofacial Surgery; though Plastic Surgery, Neurosurgery and Otorhinolaryngology also contributed to the mix of specialty demand.This national specific institutional review supports the prevailing consensus on the growing role that computer tomographic assisted biomodelling has in the surgical resection and/or reconstruction of the maxillofacial skeleton.
Functional electrical stimulation (FES) is an assistive technology shown to improve muscle condition when used appropriately and can also help patients with paralyzed or weak muscles to move. As such it has been explored as a form of exercise in the home environment. One parameter of this exploration which must be considered when interpreting the effectiveness of a device is patient compliance; that is, actual patient usage of a FES device in the home. In this short report, we discuss how the literature has historically reported compliance and propose, upon the premise of the literature, that compliance may be measured in three ways: anecdotally, externally, or procedurally. In emphasizing these methods, we stress that for clinicians or engineers to truly elucidate patient device usage, they must measure compliance by using a number of these measures.
There are too many transport/vehicles in a city/town at the present time (motor cars, lorries, buses, trolleybuses, dump trucks, ambulances, and another special machinery.Working in our cities/towns they give us three main negative factors, namely: exhaust carcinogenic gases, noise and ruts/ditches from tyres and the definite dangerous for people.In this article we plan to discuss and solve the problem connected only with the ruts and are ready to offer the new way how to reduce the rate of wear and tear for the road asphalt covering in those places where tyres are often rolling.For this purpose, the shapes both for the heavy roller and for the road covering were changed.
The present study assessed the effect of marjoram, propolis, and their combination against adenine induced chronic kidney disease (CKD) and renal dysfunction in male albino rats. Thirty-five rats weighing (200 ± 10 g) were divided into seven groups (n=5). The 1st control group, the 2nd adenine group (300 mg/kg), the 3rd marjoram group (100 mg/kg), the 4th propolis group (70 mg/kg), the 5th adenine + marjoram group, the 6th adenine + propolis group and the 7th adenine + marjoram + propolis group, all treatments were given orally for 30 consecutive days. The results showed that adenine treatment caused renal disorders with extensive tubulointerstitial fibrosis, tubular atrophy, crystal formation and marked vessel calcification in the kidney tissue associated with increasing the plasma renal biomarkers. The oxidative stress markers lipid peroxidation and protein carbonyl content were increased with a significant decrease in the activities of superoxide dismutase, catalase, and glutathione level. However, administration of marjoram and propolis separately or in combination improved kidney functions as they ameliorated the levels of renal function parameters and prevented oxidative stress. It can be concluded that marjoram and propolis in combination could cause an amazing improvement in the renal functions after adenine induced chronic renal failure and the histology of the kidney greatly recovered after the treatment with their combination. Thus, this surprise combination represents a new therapeutic strategy and gives good hope for a patient with CKD. *Correspondence to: Hani M Abdelsalam, Department of Zoology, Faculty of Science, Zagazig University, Egypt, Tel: 00201008051012; E-mail: Hani. abdelsalam@su.edu.eg
Background: The research on track and field dynamics is divided into the areas of surface rebound, sprinting with banks, sprint acceleration, and compliant running shoes. Methods: The dimensionless position (g . x)/V^2 and time (g . t)/V numbers are used for sprint acceleration, and the radius number (g . r)/V^2 is used for speed reduction on circular turns. Equivalent analog circuits are developed, representing the track as an inductor-capacitor L-C resonant circuit, and the runner as an R-L-C oscillator circuit. Results: Computer results are presented for force, acceleration, velocity, and position during impact. An Impulse Conservation theorem is developed whereby Force × Time=constant. Conclusion: In addition to a uniform 2% to 3% top speed advantage on optimally compliant surfaces, a tuned track has 11.3% ± 1.21% force reduction for all runners (force reduction factor FR=0.89).
Sleeping Beauty (SB) exhibits efficient cut-and-paste transposition in a wide range of mammalian cells.Using this characteristic, a new vector system (the SB system) was previously developed for integration of target genes into the host genome and is now used as a research tool and for gene therapy.However, there are concerns about the retransposition and the size restriction to be integrated into this system.To overcome these issues, we constructed a modified transposon vector system with lox sequences and estimated its transposable activity and Cre/lox recombination ability in HeLa cells.We also estimated the possibility of the retransposition by plasmids with defective inverted repeat/direct repeat structures presumed to be taken after Cre/lox recombination.We demonstrated that our modified transposon vector system could efficiently cause recombination mediated by the Cre/lox system following the transposition of the target genes into the genome and eliminate the possibility of retransposition of the genes.We believe our modified transposon vector system could be used not only as a research tool but also as a safer and more versatile gene integration system in the medical field.
A porcine burn model was used to demonstrate the potential of using the attenuation of the optical coherence tomography signal as an indicator of the degree of burn injury.A swept-source optical coherence tomography system amenable to operating in burn trauma centers and in surgeries was designed and built in-house.A special design feature of our optical coherence tomography system is its large stand-off distance (272 mm) between the data collecting lens terminating the sample arm and the sample surface.This feature eliminates potential contact between patient and instrument, and thereby decreases the potential for infection through remote contamination.Four contact burn types, histologically confirmed to produce superficial, superficial-intermediate, deeper-intermediate and full thickness injuries, were investigated.Burn types and matching control sites were randomly placed over a predetermined grid.The burn injuries were restricted to under 1% of the total body surface area in order to minimize systemic effects and eliminate cross-talk between the measurement sites on the grid.At each grid location, the data was acquired very fast, amounting to total acquisition times of less than 3 seconds per data set, speeds practical for use in the high-stress environment characterizing burn trauma units.We used attenuation coefficients of optical coherence tomography signal in tissue as a summary parameter for burn injury determination.This simple parameter can be computed in real-time during the OCT acquisition sequence across the burn wound providing the clinician a real-time assessment of the degree of injury.
Abstract The goal of this work was to evaluate the biological effect of the extremely low frequencies (ELFs). We started by evaluating the effect of frequencies with the anti-bacterial functions listed in the Rife frequency database on the growth of Escherichia coli. Among the 11 sets of frequencies tested, we found that only 1 set comprising frequencies below 100 Hz showed a significant effect on the growth of E. coli, and it was an enhancement effect instead of an inhibition on the growth. We further tested various sets of frequencies without anti-bacterial functions but comprising frequencies below 100 Hz, and they all exhibited a significant promoting effect on the growth of E. coli when exposed to the irradiation for 1 h. We further evaluated the effect of the ELFon the growth of E. coli by scanning from 0 to 100 Hz. The results showed that the growth rate was noticeably enhanced for the group exposed to the irradiation at the range of 0–100 Hz, with the range of 40–60 Hz being the most effective. In addition, the effect was time dependent, demonstrated by a significant increase of the growth rate observed after exposure of 1 h but a slight decrease after exposure of 16 h. The results of this study provided robust data on the biological effect of ELF on the growth of E. coli, an important group of human microbiota, which has critical implication on the safety risk of these frequencies on human health.
The Interdepartmental Research Centre of Myology (CIR-Myo), University of Padova, Italy, the A&C M-C Foundation for Translational Myology, Padova, Italy and PAGEpress, organized the 2019SpringPaduaMuscleDays: Translational Myology and Mobility Medicine, an International Conference held March 28-30, 2019 in Euganei Hills and Padova (Italy) with the help of an international team of Organizers, i.e., Helmut Kern, Jonathan C. Jarvis, Viviana Moresi, Marco Narici, Feliciano Protasi, Marco Sandri and Ugo Carraro. Presentations of Three Physiology Lectures and of the seven Sessions (I: Spinal Cord Neuromodulation and h-bFES in SC; II: Muscle epigenetics in aging and myopathies; III: Experimental approaches in animal models; IV: Face and Voice Rejuvenation; V: Muscle Imaging; VI: Official Meeting of the EU Center of Active Aging; VII: Early Rehabilitation after knee and hip replacement) were of very high levels and were following by constructive discussions. During the three days and evenings, Speakers and Attendees, in particular young attendees, had the chance to exchange further information and design potential collaborations. A half-century tradition of skeletal muscles studies, started with a research on fever, is thus continuing under the auspices of CIR-Myo, A&C M-C Foundation for Translational Myology, Padova, Italy and the European Journal of Translational Myology (EJTM). Furthermore, during the Meeting were also discussed the contents of an EJTM Special, that will be dedicated to Muscle Fascia, an under looked topic, which merits more attention. The abstracts of are excellent examples of translational research in Myology, Mobility and Medicine. Thanks to the high scientific profiles of the researchers and clinicians who are eager to present results at the PaduaMuscleDays, this was true for the past and it will be true in future events.
A 40-year-old female formal dancer revealed non-symptomatic diagnosed inflammation on the base of between the middle and the lateral cuneiforms following magnetic resonance (MR) scans.It remains unclear if there are any differences in gait function between a person who have sustained non-symptomatic diagnosed inflammation on the base of cuneiforms and those who have not.To see its relationship to the gait patterns, dynamic plantar pressure was obtained during running and it was compared against T2* values as well as plantar pressure measuring from twenty healthy subjects.In this case of a dancer's foot, the gait was modified possibly due to the non-symptomatic diagnosed inflammation on the base of cuneiforms, and hence the plantar pressure on the heel was increased compared with healthy non-dancer controls.
A number of nonlocal biological effect of chemicals were reported in recent years.In this study, we examined nonlocal effect of two antibacterial Chinese medicinal herbs (Houttuynia cordata Thunb and Sargentodoxa cuneata) on the growth of Escherichia coli.The processed herbs were placed on the transmission side of a commercially available scalar wave device, and the E. coli cultured on triplicate agar plates on the receiver side.Growth suppression was evaluated by Colony Forming Unit (CFU) determination in comparison to the control group.A significant nonlocal inhibitory effect (up to 30%) was demonstrated for the treatment group (p<0.05),indicating a success in transmitting the antibacterial function of the herbs to the E. coli cultures.Factors affecting the success rate were explored.
