ABSTRACT
Objective To analyze the dynamic response and strain of the major muscles in head-neck complex of pilot with or without wearing the helmet during carrier aircraft arrested deck landing. Methods Ten-rigid body dynamic model of human head-neck complex was created including head, seven cervical vertebrae and two thoracic vertebrae; mechanical properties of the ligaments, intervertebral discs and other surrounding soft tissues were described by lumped parameter method; mechanical properties of the 15 pairs of muscles in this human head-neck complex were represented by non-linear stress-strain relationship. The model was validated by using experimental data of dynamic responses from the human head-neck complex in a set of different types of automobile crashes. Results The overload curve and strain of this 15 pairs of muscles in head-neck complex of the pilot during arrested deck landing were obtained. The results showed that the extension of splenius cervicis was the largest. The strain of splenius cervicis could reach 50% when the pilot wore the helmet, and it could reach as high as 56% if the helmet’s weight was 2.7 kg. Conclusions Wearing helmet would extend the stretch of neck muscles, and the simulation result could be used for further evaluation on head/neck injury of the pilot.
ABSTRACT
Objective To investigate the present situation of neck injuries in military pilots, analyze possible factors that induce neck injuries and how such injuries could influence flight training, and provide suggestions for relevant physiological researches and engineering solutions. Method Questionnaires were carried out among 1 924 military pilots, including pilots of primary trainer, attacker, fighter, bomber, transporter and helicopter. The questionnaire consist of 2 parts: (1) pilots’ basic information, such as unit, age, type of aircraft, flying hours, height, weight, etc. (2) relevant issues on neck injuries, including symptoms and their influences on flight, reasons that cause the injuries, etc. Statistical analyses were conducted according to the questionnaire results. Results The investigation showed that 71.3% of the pilots had uncomfortable neck symptoms and 60.4% of them had befallen such symptoms during flight. 33.7% of the pilots had suffered neck pain and 19.2% of them reported that such pains took place during flight. Factors such as acceleration, weight of helmet and long duration of flight would be the main reasons resulting in the discomfort of neck. Bomber pilots showed the highest proportion either on the neck discomfort or on the neck pain. Conclusions Neck injuries have become the frequently occurring illness in Chinese military pilots and have affected their daily flight. The study also foresees an increased tendency on pilots’ neck injuries due to the growing requirements of flight load and training strength on fighter and attacker pilots. Therefore, great importance should be attached on neck injuries of military pilots and further studies should be conducted on physiological investigations and engineering solutions.
ABSTRACT
Objective To carry out quantitative investigation on application of emulational trunk dummy (ETD) in evaluating the opening shock of life saving parachute and provide a more reliable test method for further development. Method ETD equipped with parachute was tested in the impact experiment, where a 63.4 kg impact block was dropped from the height of 0.20 m，0.40 m，0.60 m，0.80 m respectively to simulate different opening shocks. The opening shocks were deducted by measured forces on harness and acceleration loads at the center of dummy's thorax. For comparison, 5 rigid trunk dummies (RTD) were tested under the equivalent impacts. As the contrast test, 24 male healthy subjects were also exposed under such impacts with standing and sitting posture respectively. Results Under the same impact, the peak impact value on harness exhibited maximum on RTD, minimum on subjects with sitting posture, and medium on ETD. There were significant differences between each experimental group (P<0.01). With different impact loads, the peak impact value on ETD was 2 795，3 873，4 816 and 5 736 N respectively, which was correspondingly close to that of subjects with standing posture(2 541，3 042，3 720 and 4250 N). Conclusions The result of opening shock gathered from ETD is closer to that from RTD due to ETD’s viscoelasticity, which shall certainly influence the measured opening shock. Therefore, ETD is suggested to be used in the development of live saving parachute.
ABSTRACT
Targeting dosage form is a kind of targeting drug delivery system which can be used to lock drugs aroud the target organs, tissues, cells and obtain more effective treatment for dose concentration, thus reducing the side-effects of such drugs while increasing their effeciveness. Targeting dosage form is the fourth-generation drug dosage form and it is ideal system for administration because it release the theraping drugs in the targeting-site. Particular emphasis was placed on liposome due to it was used as a drug carrier. Meanwhile, the highlights of research were on magnetic and enzyme targeting preparations. In addition, oral colon targeting drug delivery system, drugs were carried to ileocecum and release to get local and whole effect, is also an important part of targeting dosage form. The study on traditional chinese medicine (TCM) targeting dosage form is still at beginning stage in China. At present, most of study on TCM and natural products targeting drugs were focus on simple effective component and merely on TCM effective positions in relative with the difficult for determing their quality standard and procedure of preparing. It is the kernel item for TCM modernization and the key for TCM internationalization to develop new dosage form and new technology of TCM. There is a need in collaboration with multiple discipline. It will be a important research subject to develop TCM targeting preparation in the near future. TCM targeting dosage form can be classified into liposome, nanoparticles, multiple emulsion etc according to the difference of carrier and oral, rectal, colonic, nasal, dermal, ocular system on a basis of administration and so on. This paper made a summary on TCM and natural products targeting dosage form according to different targeting positions and introduce the procedure of preparing compared with the effect in vivo and manifest that TCM and natural products targeting dosage form will have good exploit prospect.