Self-aligned 0-level sealing of MEMS devices by a two layer thin film reflow process

Many micro electromechanical systems (MEMS) require a vacuum or controlled atmosphere encapsulation in order to ensure either a good performance or an acceptable lifetime of operation. Two approaches for wafer-scale zero-level packaging exist. The most popular approach is based on wafer bonding. Alternatively, encapsulation can be done by the fabrication and sealing of perforated surface micromachined membranes. In this paper, a sealing method is proposed for zero-level packaging using a thin film reflow technique. This sealing method can be done at arbitrary ambient and pressure. Also, it is self-aligned and it can be used for sealing openings directly above the MEMS device. It thus allows for a smaller die area for the sealing ring reducing in this way the device dimensions and costs. The sealing method has been demonstrated with reflowed aluminium, germanium, and boron phosphorous silica glass. This allows for conducting as well as non-conducting sealing layers and for a variety of allowable thermal budgets. The proposed technique is therefore very versatile

Biceps femoris and semitendinosus: teammates or competitors? : new insights into hamstring injury mechanisms in male football players : a muscle functional MRI study

Background: The hamstring injury mechanism was assessed by investigating the exercise-related metabolic activity characteristics of the hamstring muscles using a muscle functional MRI (mfMRI) protocol. Methods: 27 healthy male football players and 27 football players with a history of hamstring injuries (recovered and playing fully) underwent standardised mfMR Imaging. The mfMRI protocol consisted of a resting scan, a strenuous bilateral eccentric hamstring exercise and a postexercise scan. The exercise-related T2 increase or the signal intensity shift between both scans was used to detect differences in metabolic activation characteristics (1) between the different hamstring muscle bellies and (2) between the injury group and the control group. Results: A more symmetrical muscle recruitment pattern corresponding to a less economic hamstring muscle activation was demonstrated in the formerly injured group (p<0.05). The injured group also demonstrated a significantly lower strength endurance capacity during the eccentric hamstring exercise. Conclusions: These findings suggest that the vulnerability of the hamstring muscles to football-related injury is related to the complexity and close coherence in the synergistic muscle recruitment of the biceps femoris and the semitendinosus. Discrete differences in neuromuscular coordination and activity distribution, with the biceps femoris partly having to compensate for the lack of endurance capacity of the semitendinosus, probably increase the hamstring injury risk

The prevention of injuries in contact flag football

American flag football is a non-tackle, contact sport with many moderate to severe contact-type injuries reported. A previous prospective injury surveillance study by the authors revealed a high incidence of injuries to the fingers, face, knee, shoulder and ankle. The objectives of the study were to conduct a pilot-prospective injury prevention study in an attempt to significantly reduce the incidence and the severity of injuries as compared to a historical cohort, as well as to provide recommendations for a future prospective injury prevention study. A prospective injury prevention study was conducted involving 724 amateur male (mean age: 20.0 +/- A 3.1 years) and 114 female (mean age: 21.2 +/- A 7.2 years) players. Four prevention measures were implemented: the no-pocket rule, self-fitting mouth guards, ankle braces (for those players with recurrent ankle sprains) and an injury treatment information brochure. An injury surveillance questionnaire was administered to record all time-loss injuries sustained in game sessions. There was a statistically significant reduction in the number of injured players, the number of finger/hand injuries, the incidence rate and the incidence proportion between the two cohorts (p < 0.05). This one-season pilot prevention study has provided preliminary evidence that finger/hand injuries can be significantly reduced in flag football. Prevention strategies for a longer, prospective, randomised-controlled injury prevention study should include the strict enforcement of the no-pocket rule, appropriate head gear, the use of comfortable-fitting ankle braces and mouth guards, and changing the blocking rules of the game

Descriptive profile of scapulothoracic position, strength and flexibility variables in adolescent elite tennis players

Study design Descriptive study, cross-sectional design. Background Tennis requires repetitive overhead movement patterns that can lead to upper extremity injury. The scapula plays a vital role in injury-free playing. Scapular dysfunction has been associated with shoulder injury in the overhead athlete. Objectives The purpose of this study was to describe variables regarding scapular position, muscle strength and flexibility in young elite tennis players. Methods Thirty-five adolescent Swedish elite tennis players (19 boys, aged 13.6 (+/-1.4) years, 16 girls, aged 12.6 (+/-1.3) years), selected on the basis of their national ranking, underwent a clinical screening protocol consisting of: scapular upward rotation at several angles of arm elevation; isometric scapular muscle strength; and anthropometric measurement of pectoralis minor (PM) length. Results The players showed significantly more scapular upward rotation on their dominant side (p<0.001). For both genders, upper trapezius (p=0.003) and serratus anterior (p=0.01) strength was significantly greater on the dominant side, whereas middle and lower trapezius strength showed no side differences. PM was shorter on the dominant side (p<0.001), and in the female players (p=0.006) compared with the boys. Conclusion These results indicate some sports-related adaptations of young tennis players on their dominant side at the scapulothoracic level to exposure to their sport. These data may assist the clinician in the prevention and rehabilitation of sport-specific injuries in adolescent tennis players

Static and dynamic characterization of pull-in protected CMOS compatible poly-SiGe grating light valves

status: publishe

Cartilage adaptation after anterior cruciate ligament injury and reconstruction: implications for clinical management and research? A systematic review of longitudinal MRI studies

SummaryObjectiveTo summarize the current evidence of magnetic resonance imaging (MRI)-measured cartilage adaptations following anterior cruciate ligament (ACL) reconstruction and of the potential factors that might influence these changes, including the effect of treatment on the course of cartilage change (i.e., surgical vs non-surgical treatment).MethodsA literature search was conducted in seven electronic databases extracting 12 full-text articles. These articles reported on in vivo MRI-related cartilage longitudinal follow-up after ACL injury and reconstruction in “young” adults. Eligibility and methodological quality was rated by two independent reviewers. A best-evidence synthesis was performed for reported factors influencing cartilage changes.ResultsMethodological quality was heterogenous amongst articles (i.e., score range: 31.6–78.9%). Macroscopic changes were detectable as from 2 years follow-up next to or preceded by ultra-structural and functional (i.e., contact-deformation) changes, both in the lateral and medial compartment. Moderate-to-strong evidence was presented for meniscal lesion or meniscectomy, presence of bone marrow lesions (BMLs), time from injury, and persisting altered biomechanics, possibly affecting cartilage change after ACL reconstruction. First-year morphological change was more aggravated in ACL reconstruction compared to non-surgical treatment.ConclusionIn view of osteoarthritis (OA) prevention after ACL reconstruction, careful attention should be paid to the rehabilitation process and to the decision on when to allow return to sports. These decisions should also consider cartilage fragility and functional adaptations after surgery. In this respect, the first years following surgery are of paramount importance for prevention or treatment strategies that aim at impediment of further matrix deterioration. Considering the low number of studies and the methodological caveats, more research is needed

Functional assessment of the cervical spine in F-16 pilots with and without neck pain

Introduction: Spinal symptoms in fighter pilots are a serious aeromedical problem. The most common neck complaints are muscular pain and strain. The aim of the current study was to determine possible differences in the cervical range of motion (CROM), neck position sense, and neck muscle strength between pilots with and without neck pain. Methods: There were 90 male F-I 6 pilots who volunteered, of which 17 had experienced bilateral neck pain. A standardized questionnaire was used to collect personal information. The maximum isometric neck flexion/extension and lateral flexion strength, the neck position sense, and the cervical range of motion were measured. Results: There were no significant differences between healthy pilots and those with neck pain concerning neck Muscle strength and neck position sense. The neck pain group had a limited CROM in the sagittal plane (130 degrees; CI: 116 degrees-144 degrees) and in the transversal plane (155 degrees; CI: 140 degrees-170 degrees) compared to the healthy pilots. Discussion: In the current study we screened for different motor skills so that deficits Could be detected and retraining programs could be implemented when necessary. According to our results, individual retraining programs might reduce neck pain and therefore a well-instructed training program to maintain a proper active CROM should be implemented. Future Studies should investigate the effectiveness of this kind of program