Sample records for headrests

  1. The Effects of Packaging on Collision Energy Absorption of Automotive Seat Headrest

    Chen Minggang


    Full Text Available The automotive seat headrest plays an important role in the passenger protection during car crashes, and its structure parameters and performance have direct influence on the seat crashworthiness. In this paper, according to relevant regulations of GB11550-2009, collision simulation analyses of the seat headrest structure were carried out by Ls-dyna code. The law of different headrest packaging parameters on collision energy absorption was investigated to provide guidance for the headrest structure optimization design and improvement. The research results show that, with the increase of packaging of the headrest, the maximum acceleration and high acceleration duration time of head gradually decreases.

  2. Headrest position during normal driving: implication to neck injury risk in rear crashes.

    Viano, D C; Gargan, M F


    The gap and relative height of headrest behind drivers were determined for 1915 vehicles approaching an intersection on a two lane road. Vehicle type and headrest adjustment were also evaluated using film of normal driving taken by the Insurance Institute for Highway Safety. Only 10% of drivers had headrests in the most favorable position to prevent neck extension during a rearend crash. 73% of cars had adjustable headrests, but only a quarter were placed in the up position. 83% of the adjustable headrests could have been raised to better protect the driver. Hyge sled tests were run to determine biomechanical responses for the various conditions observed in normal driving. This included three headrest heights and three gaps behind the head. Neck extension from the Hybrid III dummy was normalized to the response for a high, close headrest, and injury risk was assumed to be proportional to neck extension. The current driving situation has a relative injury risk of 3.4 in rearend crashes, compared to 1.0 for the favorable condition. If all adjustable headrests were placed in the up position, the relative risk would be lowered to 2.4, a 28.3% reduction in whiplash injury risk. Public education and vehicle design should address the importance of proper headrest placement for driving safety.

  3. No trauma of the cervical spine. Automatic headrest adjustment; Kein HWS-Trauma. Kopfstuetze automatisch naeher am Kopf

    Schmuck, M.; Gaebelein, J. [Proma GmbH, Lichtenfels (Germany)


    A new headrest system developed by Proma considerably reduces the risk of injuries of the cervical spine. The idea behind it is simple and innovative: Apart from the automatic height adjustment, the headrest also has an automatic adjustment function to keep it in a position close to the head. (orig.)

  4. Seat headrest-incorporated personalized ventilation: Thermal comfort and inhaled air quality

    Melikov, Arsen Krikor; Ivanova, T.; Stefanova, G.


    and a decreased risk of airborne cross-infection when SHPV is used. Subjects assessed the air movement and the cooling provided by the SHPV as acceptable. Acceptability was unchanged over in time and increased with the increase of the air temperature. No draught was reported. The SHPV can be used in spaces where......The performance of personalized ventilation with seat headrest-mounted air supply terminal devices (ATD), named seat headrest personalized ventilation (SHPV), was studied. Physical measurements using a breathing thermal manikin were taken to identify its ability to provide clean air to inhalation...... depending on design, shape, size and positioning of the ATD, flow rate and temperature of personalized air, room temperature, clothing thermal insulation of the manikin, etc. Tracer gas was mixed with the room air. The air supplied by the SHPV was free of tracer gas. Tracer gas concentration in the air...

  5. Characteristics of Relocated Quiet Zones Using Virtual Microphone Algorithm in an Active Headrest System

    Seokhoon Ryu


    Full Text Available This study displays theoretical and experimental investigation on the characteristics of the relocated zone of quiet by a virtual microphone (VM based filtered-x LMS (FxLMS algorithm which can be embedded in a real-time digital controller for an active headrest system. The attenuation changes at the relocated zones of quiet by the variation of the distance between the ear and the error microphone are mainly examined. An active headrest system was implemented for the control experiment at a chair and consists of two (left and right secondary loudspeakers, two error microphones, two observer microphones at ear positions in a HATS, and other electronics including a dSPACE 1401 controller. The VM based FxLMS algorithm achieved an attenuation of about 22 dB in the control experiment against a narrowband primary noise by the variation of the distance between the ear and the error microphone. The important factors for the algorithm are discussed as well.

  6. Opioid-Induced Nausea Involves a Vestibular Problem Preventable by Head-Rest.

    Nadine Lehnen

    Full Text Available Opioids are indispensable for pain treatment but may cause serious nausea and vomiting. The mechanism leading to these complications is not clear. We investigated whether an opioid effect on the vestibular system resulting in corrupt head motion sensation is causative and, consequently, whether head-rest prevents nausea.Thirty-six healthy men (26.6 ± 4.3 years received an opioid remifentanil infusion (45 min, 0.15 μg/kg/min. Outcome measures were the vestibulo-ocular reflex (VOR gain determined by video-head-impulse-testing, and nausea. The first experiment (n = 10 assessed outcome measures at rest and after a series of five 1-Hz forward and backward head-trunk movements during one-time remifentanil administration. The second experiment (n = 10 determined outcome measures on two days in a controlled crossover design: (1 without movement and (2 with a series of five 1-Hz forward and backward head-trunk bends 30 min after remifentanil start. Nausea was psychophysically quantified (scale from 0 to 10. The third controlled crossover experiment (n = 16 assessed nausea (1 without movement and (2 with head movement; isolated head movements consisting of the three axes of rotation (pitch, roll, yaw were imposed 20 times at a frequency of 1 Hz in a random, unpredictable order of each of the three axes. All movements were applied manually, passively with amplitudes of about ± 45 degrees.The VOR gain decreased during remifentanil administration (p<0.001, averaging 0.92 ± 0.05 (mean ± standard deviation before, 0.60 ± 0.12 with, and 0.91 ± 0.05 after infusion. The average half-life of VOR recovery was 5.3 ± 2.4 min. 32/36 subjects had no nausea at rest (nausea scale 0.00/0.00 median/interquartile range. Head-trunk and isolated head movement triggered nausea in 64% (p<0.01 with no difference between head-trunk and isolated head movements (nausea scale 4.00/7.25 and 1.00/4.5, respectively.Remifentanil reversibly decreases VOR gain at a half

  7. Vertical Impact Tests of a Modified F/FB-111 Crew Seat to Evaluate Headrest Position and Restraint Configuration Effects


    center of gravity over or slightly forward of the longitudinal axis of the cervical vertebrae . This recommendation was based on the presumption that a...161 23.2 117 - 203 Stature 68.4 3.05 62.9 - 73.6 Cervicale Height 58.7 2.87 55.5 - 63.8 Trochanteric Height 35.8 2.21 32.3 - 39.9 Tibiale Height 17.5

  8. Design Thought Of Improving The Reduced Mass Precision Of Headrest Striking Testing Machine%浅谈提高头枕撞击试验机折算质量精度的设计思想



    随着人类的不断进步和社会的快速发展,汽车这种交通运输工具,在运输、救护、起吊、消防、清扫等方面发挥着不可替代的作用。由于汽车是一种高速运动的物体,安全问题备受汽车设计人员的关注。世界上各个汽车生产国针对汽车安全问题制定了各种相应的规定和一些强制性国家标准。汽车在设计和生产过程中都要以这些规定和强制性国家标准为依据,通过各种试验来满足安全要求。%With the rapid development of human society, motor vehicle plays important roles in transportation, rescue, crane, fire - proof and clean as a communications and transportation tool. Its safety problem is pay great attention by all the designers. Many regulations and mandatory national standard was formulated by many production countries in allusion to the safety problems. These regulations and standards should be obeyed by performing many experiments in the design and oroduction process to meat the safety demands.

  9. Effects of Variable Helmet Weight on Human Response to -Gx Impact


    properties. Test programs conducted by Perry, Buhrman, and associates [1,6,7,8,10] at the Air Force Research Laboratory’s former Biomechanics Branch...statistical analysis. The measured headrest pre-impact loads were statistically evaluated for all of the test runs . The headrest pre-impact load is...Appendix A. 4.1 Acceleration Response Test runs that were greater than 2.5 standard deviations from the mean were identified and removed from the

  10. Characterization of pediatric wheelchair kinematics and wheelchair tiedown and occupant restraint system loading during rear impact.

    Fuhrman, Susan I; Karg, Patricia; Bertocci, Gina


    This study characterizes pediatric wheelchair kinematic responses and wheelchair tiedown and occupant restraint system (WTORS) loading during rear impact. It also examines the kinematic and loading effects of wheelchair headrest inclusion in rear impact. In two separate rear-impact test scenarios, identical WC19-compliant manual pediatric wheelchairs were tested using a seated Hybrid III 6-year-old anthropomorphic test device (ATD) to evaluate wheelchair kinematics and WTORS loading. Three wheelchairs included no headrests, and three were equipped with slightly modified wheelchair-mounted headrests. Surrogate WTORS properly secured the wheelchairs; three-point occupant restraints properly restrained the ATD. All tests used a 26km/h, 11g rear-impact test pulse. Headrest presence affected wheelchair kinematics and WTORS loading; headrest-equipped wheelchairs had greater mean seatback deflections, mean peak front and rear tiedown loads and decreased mean lap belt loads. Rear-impact tiedown loads differed from previously measured loads in frontal impact, with comparable tiedown load levels reversed in frontal and rear impacts. The front tiedowns in rear impact had the highest mean peak loads despite lower rear-impact severity. These outcomes have implications for wheelchair and tiedown design, highlighting the need for all four tiedowns to have an equally robust design, and have implications in the development of rear-impact wheelchair transportation safety standards.

  11. The Evaluation of Skin Toxicity during Brain Tumor Irradiation Dose Calculation

    Oxana A. Pashkovskaya


    Full Text Available Background: Radiotherapy is the keystone in brain tumor treatment, including posterior fossa tumors, and can achieve better patient health-related quality of life. Radiation exposure can be associated with the risk of skin radiation injuries. Accurate tumor and critical structure delineations and precise dose planning may improve the outcomes and decrease radiation complications. The objective of this study was to compare the influence of the headrest and treatment couch during dose planning, on the dose distributions and skin injury post irradiation. Material and Methods: Treatment planning calculations were performed for 14 brain tumor patients using the volumetric modulated arc therapy (VMAT to study the dose distribution and dose-volume histograms (DVH. We compared the following three cases of general patient contours: patient body contour alone, body contour including the headrest, and body contour with headrest, couch and immobilization mask. The same configuration beams were used in all these cases; general patient contours alone were altered. Results: For dose estimations, the skin was delineated as a 2 mm layer beneath the patient’s body contour. The comparisons showed that the average dose on the skin, among all the patients included in this study, in the case of body contour alone is 3.3 Gy, whereas in the case of body contour with headrest, it is 6.3 Gy and in the case of body contour with headrest, couch and immobilization mask it is 9.4 Gy. Conclusion: For brain tumors, located in the posterior fossa and near the patient’s skin, the skin needed to be included as a critical structure. The skin dose should be considered when evaluating treatment plans, taking into account the bolus effect of the headrest and couch.

  12. Rehabilitation of Visual and Perceptual Dysfunction after Severe Traumatic Brain Injury


    camera, operator monitor, chinrest/headrest assembly, and adjustable height table and chair (Fig 3). The patient’s head is held at 45 cm from the screen...ability to walk or self ambulate wheelchair , no severe vertigo or vestibular 11 dysfunction, no history of seizures in prior 3 months, and willingness

  13. Head of the bed elevation angle recorder for intensive care unit

    Krefft, Maciej; Zamaro-Michalska, Aleksandra; Zabołotny, Wojciech M.; Zaworski, Wojciech; Grzanka, Antoni; Łazowski, Tomasz; Tavola, Mario; Siewiera, Jacek; Mikaszewska-Sokolewicz, Małgorzata


    This paper presents a recording system optimized for long term measurement of bed headrest elevation angle in the Intensive Care Unit. The continuous monitoring of this parameter allows to find the correlation between the patient's position in bed and the risk of the Ventilator Associated Pneumonia (VAP), a very serious problem in therapy of critically ill patients. Recorder might be be an important tool to evaluate the "care bundles" - sets of preventive procedures recommended for treatment of patients in the ICU.

  14. Cervical spine motion in manual versus Jackson table turning methods in a cadaveric global instability model.

    DiPaola, Matthew J; DiPaola, Christian P; Conrad, Bryan P; Horodyski, MaryBeth; Del Rossi, Gianluca; Sawers, Andrew; Bloch, David; Rechtine, Glenn R


    A study of spine biomechanics in a cadaver model. To quantify motion in multiple axes created by transfer methods from stretcher to operating table in the prone position in a cervical global instability model. Patients with an unstable cervical spine remain at high risk for further secondary injury until their spine is adequately surgically stabilized. Previous studies have revealed that collars have significant, but limited benefit in preventing cervical motion when manually transferring patients. The literature proposes multiple methods of patient transfer, although no one method has been universally adopted. To date, no study has effectively evaluated the relationship between spine motion and various patient transfer methods to an operating room table for prone positioning. A global instability was surgically created at C5-6 in 4 fresh cadavers with no history of spine pathology. All cadavers were tested both with and without a rigid cervical collar in the intact and unstable state. Three headrest permutations were evaluated Mayfield (SM USA Inc), Prone View (Dupaco, Oceanside, CA), and Foam Pillow (OSI, Union City, CA). A trained group of medical staff performed each of 2 transfer methods: the "manual" and the "Jackson table" transfer. The manual technique entailed performing a standard rotation of the supine patient on a stretcher to the prone position on the operating room table with in-line manual cervical stabilization. The "Jackson" technique involved sliding the supine patient to the Jackson table (OSI, Union City, CA) with manual in-line cervical stabilization, securing them to the table, then initiating the table's lock and turn mechanism and rotating them into a prone position. An electromagnetic tracking device captured angular motion between the C5 and C6 vertebral segments. Repeated measures statistical analysis was performed to evaluate the following conditions: collar use (2 levels), headrest (3 levels), and turning technique (2 levels). For all

  15. STS-31 crewmembers during simulation on the flight deck of JSC's FB-SMS


    On the flight deck of JSC's fixed based (FB) shuttle mission simulator (SMS), Mission Specialist (MS) Steven A. Hawley (left), on aft flight deck, looks over the shoulders of Commander Loren J. Shriver, seated at the commanders station (left) and Pilot Charles F. Bolden, seated at the pilots station and partially blocked by the seat's headrest (right). The three astronauts recently named to the STS-31 mission aboard Discovery, Orbiter Vehicle (OV) 103, go through a procedures checkout in the FB-SMS. The training simulation took place in JSC's Mission Simulation and Training Facility Bldg 5.

  16. Multichannel control systems for the attenuation of interior road noise in vehicles

    Cheer, Jordan; Elliott, Stephen J.


    This paper considers the active control of road noise in vehicles, using either multichannel feedback control, with both headrest and floor positioned microphones providing feedback error signals, or multichannel feedforward control, in which reference signals are provided by the microphones on the vehicle floor and error signals are provided by the microphones mounted on the headrests. The formulation of these control problems is shown to be similar if the constraints of robust stability, limited disturbance enhancement and open-loop stability are imposed. A novel formulation is presented for disturbance enhancement in multichannel systems, which limits the maximum enhancement of each individual error signal. The performance of these two systems is predicted using plant responses and disturbance signals measured in a small city car. The reduction in the sum of the squared pressure signals at the four error microphones for both systems is found to be up to 8 dB at low frequencies and 3 dB on average, where the sound level is particularly high from 80 to 180 Hz. The performance of both systems is found to be robust to measured variations in the plant responses. The enhancements in the disturbance at higher frequencies are smaller for the feedback controller than for the feedforward controller, although the performance of the feedback controller is more significantly reduced by the introduction of additional delay in the plant response.

  17. Investigation on occupant ejection in high severity rear impact based on post mortem human subject sled tests.

    Petit, Philippe; Luet, Carole; Potier, Pascal; Vallancien, Guy


    Occupant protection in rear impact involves two competing challenges. On one hand, allowing a deformation of the seat would act as an energy absorber in low severity impacts and would consequently decrease the risk of neck injuries. However, on the other hand, large deformations of the seat may increase the likelihood of occupant ejection in high severity cases. Green et al. 1987 analyzed a total of 919 accidents in Great Britain. They found that occupant ejection resulted in a risk of severe injuries and fatalities between 3.6 and 4.5 times higher than those cases where no ejection was observed. The sample included single front, side and rear impacts as well as multiple impacts and rollover. The rate of belt use in the sample was 50%. While this analysis included all forms of impact scenarios, nevertheless, it highlights the relative injury severity of occupant ejection. Extensive literature search has found no full-scale rear impact tests involving Post Mortem Human Subjects (PMHS) conducted in a laboratory environment and resulting in ejection. This paper describes a total of 10 sled tests conducted on 3 belted PMHS using a simplified seat design composed of rigid plates assembled such that the angular and linear stiffness of the seatback (including the foam) was modeled. The initial angular position and the range of motion of the seatback, the size of the PMHS, the slack length of the seatbelt, the angular stiffness of the seatback, and the use of headrest were varied in the test matrix while the pulse was kept constant (triangular acceleration with a peak of 17 G at 30 ms and a duration of 95 ms). In the test series, the tests were not run randomly but the likelihood of occupant ejection was increased systematically until ejection occurred. PMHS seat ejection was observed only for the 95th percentile, initially positioned with a seatback angle relative to the vertical equal to 22°, a range of seatback angular motion equal to 44° and no headrest. Repeating

  18. Feedback control of sound

    Rafaely, Boaz

    This thesis is concerned with the development an application of feedback control techniques for active sound control. Both fixed and adaptive controllers are considered. The controller design problem for active sound control is formulated as a constrained optimisation problem with an H2 performance objective, of minimising the variance of the control error, and H2 and H∞ design constraints involving control power output, disturbance enhancement, and robust stability. An Internal Model Controller with an FIR control filter is assumed. Conventional H2 design methods for feedback controllers are studied first. Although such controllers can satisfy the design constraints by employing effort terms in the quadratic cost function, they do not achieve the best possible performance, and when adapted using LMS-based algorithms, they suffer from instabilities if the plant response varies significantly. Improved H2/H∞ design methods for fixed and adaptive controllers are then developed, which achieve the best H2 performance under the design constraints, offer an improved stability when made adaptive, and in general outperform the conventional H2 controllers. The H2/H∞ design problems employ convex programming to ensure a unique solution. The Sequential Quadratic Programming methods is used for the off-line design of fixed controllers, and penalty and barrier function methods, together with frequency domain LMS-based algorithms are employed in the H2/H∞ adaptive controllers. The controllers studied and developed here were applied to three active sound control systems: a noise-reducing headset, an active headrest, and a sound radiating panel. The emphasis was put on developing control strategies that improve system performance. First, a high performance controller for the noise-reducing headset was implemented in real-time, which combines analogue and adaptive digital controllers, and can thus reject disturbances which has both broad-band and periodic components. Then

  19. Active control of road booming noise in automotive interiors.

    Oh, Shi-Hwan; Kim, Hyoun-suk; Park, Youngjin


    An active feedforward control system has been developed to reduce the road booming noise that has strong nonlinear characteristics. Four acceleration transducers were attached to the suspension system to detect reference vibration and two loudspeakers were used to attenuate the noise near the headrests of two front seats. A leaky constraint multiple filtered-X LMS algorithm with an IIR-based filter that has fast convergence speed and frequency selective controllability was proposed to increase the control efficiency in computing power and memory usage. During the test drive on the rough asphalt and turtle-back road at a constant speed of 60 km/h, we were able to achieve a reduction of around 6 dB of A-weighted sound pressure level in the road booming noise range with the proposed algorithm, which could not be obtained with the conventional multiple filtered-X LMS algorithm.

  20. Feasibility of cervical intramedullary diffuse glioma resection using intraoperative magnetic resonance imaging.

    Giordano, Mario; Gerganov, Venelin M; Metwali, Hussam; Fahlbusch, Rudolf; Samii, Amir; Samii, Madjid; Bertalanffy, Helmut


    Intraoperative magnetic resonance imaging (iopMRI) actually has an important role in the surgery of brain tumors, especially gliomas and pituitary adenomas. The aim of our work was to describe the advantages and drawbacks of this tool for the surgical treatment of cervical intramedullary gliomas. We describe two explicative cases including the setup, positioning, and the complete workflow of the surgical approach with intraoperative imaging. Even if the configuration of iopMRI equipment was originally designed for cranial surgery, we have demonstrated the feasibility of cervical intramedullary glioma resection with the aid of high-field iopMRI. This tool was extremely useful to evaluate the extent of tumor removal and to obtain a higher resection rate, but still need some enhancement in the configuration of the headrest coil and surgical table to allow better patient positioning.

  1. A radiolucent chair for sitting-posture radiographs in non-ambulatory children: use in biplanar digital slot-scanning

    Bouloussa, Houssam; Dubory, Arnaud; Bachy, Manon [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Orthopaedics, Paris Cedex 12 (France); Seiler, Catherine [Groupe Lagarrigue, Clichy (France); Morel, Baptiste [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Imaging, Paris (France); Vialle, Raphael [Universite Pierre et Marie Curie-Paris 6, Armand Trousseau Hospital, Department of Pediatric Orthopaedics, Paris Cedex 12 (France); Armand Trousseau Hospital, The MAMUTH Hospital-University Department for Innovative Therapies in Musculoskeletal Diseases, Paris (France)


    EOS imaging (EOS System; EOS imaging, Paris, France) enables fast 2-D/3-D imaging of children in standing load-bearing position. Non-ambulatory children with neuromuscular scoliosis need evaluation of their spinal balance while in a normal daily position. We designed a customized chair fitting the EOS patient-area dimensions to obtain images in natural sitting postures. The chair is a 360 rotating orthopaedic chair made of fully radiolucent polyethylene and equipped with an adjustable headrest and three-point belts. Out of 41 consecutive patients, 36 (88%, 95% confidence interval 74-96%) had successful imaging. In most patients with severe neuromuscular trunk deformities, the EOS system combined with our chair was useful for assessing preoperative trunk collapse, pelvic obliquity and postoperative corrections in all planes. This specific device changed our daily practice for the assessment of spinal deformities in non-ambulatory patients. (orig.)

  2. Design and Fabrication of an Adjustable Sitting Inclinations Spinal Cord Rehabilitation Chair

    Ajao, K. R.; Yahaya, T.; Ajimotokan, H. A.; Adeleke, A. A.; Bello, M.; Ojegbenro, O.


    The adjustable sitting inclination rehabilitation chair was fabricated with mild steel and soft upholstered fabric was used for the overlay on the seat, headrest and armrest. The components were coupled with a linear actuator at the upper frame for the reclining of the backrest about it axis. The wheels are located outboard of the seat of the chair to enhance stability while foot rest supports the posterior weight of the users. The narrow seat allows free movement of the leg when the user is seated. Sitting inclinations of 120 and 135° protect the spine disc from compression and proffer more comfort for the users than other angles experimented. The adjustable sitting inclination SCRC is simple and affordable for low-income people with Spinal cord injury, especially for those in developing countries in order to support other therapies for their recovery processes.

  3. Activities, postures and comfort perception of train passengers as input for train seat design.

    Groenesteijn, Liesbeth; Hiemstra-van Mastrigt, Suzanne; Gallais, Cedric; Blok, Merle; Kuijt-Evers, Lottie; Vink, Peter


    Working in the train is a part of new ways of working. However, the ideal working position is unknown. Moreover, the ideal position for leisure and relaxing is also unknown. This article defines what activities train passengers mainly perform and which corresponding postures are seen. Based on the observations on actual train rides, four main activities could be identified: Reading, Staring/sleeping, Talking and Working on laptop. Working on laptop was the activity with the longest duration and talking had the shortest duration. Associated with these four activities, a top eight of different postures were observed. Except for headrest comfort, comfort scores were not significantly different between activities. The top eight corresponding postures combined with comfort scores showed that per activity different postures were observed and the comfort scores varied in relation to the combination of posture and activity. Nearly for all activities, the majority of passengers preferred adjustability options to fit the seat to the performed activity.

  4. Exploring the design of a lightweight, sustainable and comfortable aircraft seat.

    Kokorikou, A; Vink, P; de Pauw, I C; Braca, A


    Making a lightweight seat that is also comfortable can be contradictory because usually comfort improvement means adding a feature (e.g. headrest, adjustable lumbar support, movable armrests, integrated massage systems, etc.), which makes seats heavier. This paper explores the design of an economy class aircraft seat that aims to be lightweight, comfortable and sustainable. Theory about comfort in seats, ergonomics, lightweight design, Biomimicry and Cradle to cradle was studied and resulted in a list of requirements that the new seat should satisfy. The design process resulted in a new seat that is 36% lighter than the reference seat, which showed that a significant weight reduction can be achieved. This was completed by re-designing the backrest and seat pan and integrating their functions into a reduced number of parts. Apart from the weight reduction that helps in reducing the airplane's environmental impact, the seat also satisfies most of the other sustainability requirements such as the use of recyclable materials, design for disassembly, easy to repair. A user test compared the new seat with a premium economy class aircraft seat and the level of comfort was similar. Strong points of the new design were identified such as the lumbar support and the cushioning material, as well as shortcomings on which the seat needs to be improved, like the seat pan length and the first impression. Long term comfort tests are still needed as the seat is meant for long-haul flights.

  5. Hybrid Feedforward-Feedback Noise Control Using Virtual Sensors

    Bean, Jacob; Fuller, Chris; Schiller, Noah


    Several approaches to active noise control using virtual sensors are evaluated for eventual use in an active headrest. Specifically, adaptive feedforward, feedback, and hybrid control structures are compared. Each controller incorporates the traditional filtered-x least mean squares algorithm. The feedback controller is arranged in an internal model configuration to draw comparisons with standard feedforward control theory results. Simulation and experimental results are presented that illustrate each controllers ability to minimize the pressure at both physical and virtual microphone locations. The remote microphone technique is used to obtain pressure estimates at the virtual locations. It is shown that a hybrid controller offers performance benefits over the traditional feedforward and feedback controllers. Stability issues associated with feedback and hybrid controllers are also addressed. Experimental results show that 15-20 dB reduction in broadband disturbances can be achieved by minimizing the measured pressure, whereas 10-15 dB reduction is obtained when minimizing the estimated pressure at a virtual location.

  6. A Research on Neck Movement and Injury After Driver Backs to Seat in the Later Stage of Frontal Crash%正面碰撞后期驾驶员复位后颈部运动与伤害的研究

    洪亮; 葛如海


    In view of the present situation of the lack of research on the neck injury in the later stage of crash process after driver backs to seat with his waist pressing against seat back under the actions of air bag reaction force and the constraint force of seat belt, the movement states of driver’s upper and lower necks is studied to ana-lyze the effects of seat parameters on neck injuries. To this end, based on the related dimension of passenger com-partment and performance parameters of a car, a simulation model for the constraint system of driver is built with crash simulation software MADYMO and a simulation is conducted and verified by tests. The results indicate that the peak stretch bending moment of upper neck decreases with the reduction of headrest stiffness while decreasing the stiffness of upper seat back and the rotational stiffness of seatback recliner can significantly reduce the peak stretch bending moments of both upper and lower neck and neck injury indicators Nkm and Nij . Reasonably increasing the forward inclination of headrest can greatly reduce the peak stretch bending moment of lower neck, but over doing may lead to the increase of neck injury indicators.%针对目前国内外对正面碰撞后期,驾驶员在安全气囊反弹力与安全带约束力作用下,向后复位运动,其腰部与座椅靠背接触后的颈部伤害研究很少的现状,进行了驾驶员上、下颈部运动状态研究,并分析座椅特征参数对颈部伤害的影响。为此以某型轿车乘员室相关尺寸和性能参数为依据,采用碰撞仿真软件 MADYMO 建立了驾驶员约束系统仿真模型,并进行仿真与试验验证。结果表明:减小座椅头枕刚度,可降低上颈部伸张弯矩峰值;减小靠背上部刚度与靠背倾角调节器转动刚度,可显著降低上、下颈部伸张弯矩峰值和颈部伤害指标 Nkm与 Nij;增加头枕前倾角,可大幅降低下颈部伸张弯矩峰值,但过大的头

  7. Development of an Integrated Test Bench for Automotive Occupant Restraint System%汽车乘员约束系统综合试验台的研制

    白中浩; 徐正; 颜强; 张前斌


    Based on regulations both at home and abroad for the strength test of automotive seats and safety belt anchorage, an integrated test bench for occupant restraint system is developed, with which the tests of seat stiffness , safety belt anchorage strength and the performance of head-rest can be conducted. A FE model of the master frame of test bench is built and its strength is analyzed with software ANSYS. The control system of test bench is developed by using virtual instrument technology, and the strength test of seats assembly and safety belt anchorage are performed on the test bench. The results demonstrate that the test bed developed can meet the requirements of relevant test regulations and can be used for the research and development of automotive occupant restraint system.%基于国内外汽车座椅和安全带固定点强度试验法规,开发了可同时进行座椅刚度、安全带固定点强度测试和头枕性能等测试的乘员约束系统综合试验台.采用ANSYS软件建立了试验台主台架的有限元模型对主台架进行强度分析;应用虚拟仪器技术开发了该试验台的控制系统,并利用该试验台进行了座椅总成静强度试验和安全带固定点强度试验.结果表明,该试验台能满足相关试验法规的要求,可用于对乘员约束系统的研究和开发.

  8. Biomechanics and the wheelchair.

    McLaurin, C A; Brubaker, C E


    Wheelchair biomechanics involves the study of how a wheelchair user imparts power to the wheels to achieve mobility. Because a wheelchair can coast, power input need not be continuous, but each power strike can be followed by a period of recovery, with the stroking frequency depending on user preferences and the coasting characteristics of the wheelchair. The latter is described in terms of rolling resistance, wind resistance and the slope of the surface. From these three factors the power required to propel the wheelchair is determined, and must be matched by the power output of the user. The efficiency of propulsion is the ratio of this power output to the metabolic cost and is typically in the order of 5% in normal use. The features required in a wheelchair depend upon user characteristics and intended activities. The ideal wheelchair for an individual will have the features that closely match these characteristics and activities. Thus prescription is not just choosing a wheelchair, but choosing the components of the wheelchair that best serve the intended purpose. In this paper, each component is examined for available options and how these options effect the performance of the wheelchair for the individual. The components include wheels, tyres, castors, frames, bearings, materials, construction details, seats, backrests, armrests, foot and legrests, headrests, wheel locks, running brakes, handrims, levers, accessories, adjustments and detachable parts. Each component is considered in relation to performance characteristics including rolling resistance, versatility, weight, comfort, stability, maneouvrability, transfer, stowage, durability and maintenance. Where they exist, wheelchair standards are referred to as a source of information regarding these characteristics.

  9. Initial clinical experience with scanned proton beams at the Italian National Center for Hadrontherapy (CNAO).

    Tuan, J; Vischioni, B; Fossati, P; Srivastava, A; Vitolo, V; Iannalfi, A; Fiore, M R; Krengli, M; Mizoe, J E; Orecchia, R


    We report the initial toxicity data with scanned proton beams at the Italian National Center for Hadrontherapy (CNAO). In September 2011, CNAO commenced patient treatment with scanned proton beams within two prospective Phase II protocols approved by the Italian Health Ministry. Patients with chondrosarcoma or chordoma of the skull base or spine were eligible. By October 2012, 21 patients had completed treatment. Immobilization was performed using rigid non-perforated thermoplastic-masks and customized headrests or body-pillows as indicated. Non-contrast CT scans with immobilization devices in place and MRI scans in supine position were performed for treatment-planning. For chordoma, the prescribed doses were 74 cobalt grey equivalent (CGE) and 54 CGE to planning target volume 1 (PTV1) and PTV2, respectively. For chondrosarcoma, the prescribed doses were 70 CGE and 54 CGE to PTV1 and PTV2, respectively. Treatment was delivered five days a week in 35-37 fractions. Prior to treatment, the patients' positions were verified using an optical tracking system and orthogonal X-ray images. Proton beams were delivered using fixed-horizontal portals on a robotic couch. Weekly MRI incorporating diffusion-weighted-imaging was performed during the course of proton therapy. Patients were reviewed once weekly and acute toxicities were graded with the Common Terminology Criteria for Adverse Events (CTCAE). Median age of patients = 50 years (range, 21-74). All 21 patients completed the proton therapy without major toxicities and without treatment interruption. Median dose delivered was 74 CGE (range, 70-74). The maximum toxicity recorded was CTCAE Grade 2 in four patients. Our preliminary data demonstrates the clinical feasibility of scanned proton beams in Italy.

  10. SU-C-19A-06: A Robust and Affordable Table Indexing Approach for Total Lymphoid Irradiation Treatment

    Yu, S; Fahimian, B; Kenyon, M; Hsu, A [Stanford University, Stanford, CA (United States)


    Purpose: Total lymphoid irradiation (TLI) is conventionally delivered through the dosimetric matching of mantle, spleen, and pelvis fields, necessitating multiple isocenters delivered through a combination of couch shifts and sliding of patients relative to the couch rendering the technique susceptible to shifting errors. To address this challenge, a novel technique for the couch indexing of TLI treatments is developed and evaluated through a multi-patient pilot trial. Methods: An immobilization device was designed consisting of a movable indexed slide board with an Exact Lok-Bar drilled into it. A Timo headrests were used fixate the head of the patient relative to the slide board. For the Varian Exact Couch™, the immobilization board was connected to the H3 notch to avoid the metal infrastructure of the couch for the delivery of the mantle and spleen fields. For tall patients the required shift for the pelvis isocenter reaches the shifting limit and the board was slid from H3 to H4 (a fixed distance of 14 cm). A total 22 patients were stratified in two groups of 11, one consisting of the conventional setup, and one group with the proposed immobilization technique. Results: The standard deviations (SD) of the couch positions in lateral, longitudinal, and vertical directions for 10 fractions for each patient in both groups were calculated. In the non-indexed group, the positioning SD ranged from 0.9 to 4.7 cm. Using our device, the positioning SD was reduced to a range of 0.2 to 0.9 cm, with the longitudinal direction showing the largest improvement. Conclusion: Matched field TLI remains error prone to geometrical misses. The feasibility of full indexing TLI treatments was validated and shown to result in a significant reduction of positioning errors.

  11. SU-E-T-633: Preparation and Planning of a VMAT Multi - Arc Radiation Therapy Technique for Full Scalp Treatment

    Araujo, C; Bardock, A; Berkelaar, S; Gillund, D; McGee, K; Mohamed, I; Lapointe, C [British Columbia Cancer Agency, Kelowna, BC (Canada)


    Purpose: The target volume for angiosarcoma of the scalp encompasses the entire scalp. Full scalp radiotherapy (FSRT) requires careful design of required bolus, immobilization and marking of the field before the patient CT is acquired. A VMAT multi-arc technique was designed to deliver FSRT for a patient with angiosarcoma of the scalp to a dose of 6000cGy in 25 fractions. Methods: A custom bolus helmet was fabricated from a 0.5 cm thick sheet of aquaplast material, which was molded to the patient’s head. With the bolus helmet in place the patient was then positioned supine on a H&N immobilization board. A custom vaclock bag positioned on a standard headrest and a thermoplastic mask were used to immobilize the patient. Additional bolus to cover the remaining treatment area was attached to the mask. We acquired two CT scans of the patient’s head, one in treatment position and an additional scan without the immobilization mask with wires marking the treatment area that the oncologist had delineated on the patient’s skin. The second scan was registered to the first and used to define the treatment CTV. A four-arc VMAT treatment planned using Varian-Eclipse was optimized to cover the skin with a PTV margin while sparing the brain and limiting the dose to the optic apparatus and lacrimal glands. Daily treatment setup was verified using anterior and lateral kV on-board-imaging. To verify the treated dose, TLDs were positioned on the patient’s scalp during one fraction. Results: With full dose coverage to the PTV, the mean dose to the brain was less than 24 Gy. The dose measured by the TLDs (mean difference 1%, standard deviation 4%)showed excellent agreement with the treatment planning calculation. Conclusion: FSRT delivered with a bolus helmet and a VMAT multi-arc technique can be accurately delivered with high dose uniformity and conformality.

  12. SU-E-J-231: Comparison of Delineation Variability of Soft Tissue Volume and Position in Head-And-Neck Between Two T1-Weighted Pulse Sequences Using An MR-Simulator with Immobilization

    Wong, O; Lo, G; Yuan, J; Law, M; Ding, A; Cheng, K; Chan, K; Cheung, K; Yu, S [Hong Kong Sanatorium & Hospital, Hong Kong (Hong Kong)


    Purpose: There is growing interests in applying MR-simulator(MR-sim) in radiotherapy but MR images subject to hardware, patient and pulse sequence dependent geometric distortion that may potentially influence target definition. This study aimed to evaluate the influence on head-and-neck tissue delineation, in terms of positional and volumetric variability, of two T1-weighted(T1w) MR sequences on a 1.5T MR-sim Methods: Four healthy volunteers were scanned (4 scans for each on different days) using both spin-echo (3DCUBE, TR/TE=500/14ms, TA=183s) and gradient-echo sequences (3DFSPGR, TE/TR=7/4ms, TA=173s) with identical coverage, voxel-size(0.8×0.8×1.0mm3), receiver-bandwidth(62.5kHz/pix) and geometric correction on a 1.5T MR-sim immobilized with personalized thermoplastic cast and head-rest. Under this setting, similar T1w contrast and signal-to-noise ratio were obtained, and factors other than sequence that might bias image distortion and tissue delineation were minimized. VOIs of parotid gland(PGR, PGL), pituitary gland(PIT) and eyeballs(EyeL, EyeR) were carefully drawn, and inter-scan coefficient-of-variation(CV) of VOI centroid position and volume were calculated for each subject. Mean and standard deviation(SD) of the CVs for four subjects were compared between sequences using Wilcoxon ranksum test. Results: The mean positional(<4%) and volumetric(<7%) CVs varied between tissues, majorly dependent on tissue inherent properties like volume, location, mobility and deformability. Smaller mean volumetric CV was found in 3DCUBE, probably due to its less proneness to tissue susceptibility, but only PGL showed significant difference(P<0.05). Positional CVs had no significant differences for all VOIs(P>0.05) between sequences, suggesting volumetric variation might be more sensitive to sequence-dependent delineation difference. Conclusion: Although 3DCUBE is considered less prone to tissue susceptibility-induced artifact and distortion, our preliminary data showed

  13. 眼科俯卧位专用床的研制与临床应用%Development and clinical application of the ophthalmological prone-position-bed

    陆银春; 周媛婷; 苏纯音; 武志峰


    目的:设计研制合理的俯卧位专用床,以解决患者俯卧位时间过长时所导致的颜面部压痛、肩颈部和腰部酸痛及肢体麻木等不适症状。方法:研制的俯卧位专用床核心部件包括头枕升降控制箱、头枕多角度转向球、头枕位置紧固手刹以及头枕升降摇柄等。结果:该装备能更精准地调整患者俯卧时的头位,极大地增加了患者的舒适度,确保了患者正确体位的长时间维持。结论:该装置的各项功能对视网膜成功复位起到了使用便利、安全可靠的作用,值得在临床上推广使用。%Objective: The position of vasectomy surgery patients can directly affect the final results of the surgery, and special prone-position-beds need to be designed to resolve the indisposed symptoms of patients like facial tenderness, shoulder and neck pain, waist ache, numbness due to holding the prone position for too long. Methods:As needed, a special prone-position-bed is developed, of which the core components include:headrest lift control box, multi-angle steering ball, tighten handbrake, lifting handle, etc. Results:The equipment can adjust the head position more accurately while the patient is in prone position, and could greatly increase patient comfort. This special bed ensures the long maintainace of the proper patient position and can effectively reduce patient discomfort by prone position like insomnia, stress, anxiety, depression, frustration, anger, and hostility and pressure ulcers. Conclusion:The special prone-position-bed is very popular with lots of patients;it can adjust the head position more accurately, greatly increases patient comfort, ensures the long maintainace of the proper patient position, and has a great role in the success reset of retina. Practice has proved that the device is convenient, safe and reliable. Its clinical use could be promoted.

  14. Repeatability and reproducibility of corneal thickness using SOCT Copernicus HR.

    Vidal, Silvia; Viqueira, Valentín; Mas, David; Domenech, Begoña


    cornea for anterior segment scanning required that patients were positioned slightly farther away from the machine head-rest than in the setup for retinal imaging. © 2013 The Authors. Clinical and Experimental Optometry © 2013 Optometrists Association Australia.

  15. Preliminary experience of fractionated stereotactic radiosurgery with extend system of Gamma Knife

    Raj Bisht


    Full Text Available Purpose: The purpose of this study is to present multisession stereotactic radiosurgery with initial experience using custom made extend system (ES of Gamma Knife.Methods: The ES is comprised of a carbon fiber frame also called extend frame, vacuum head rest cushion, patient surveillance unit and a configurable front piece with dental impression tray. The extend frame is a rigid connection between patient's head and patient positioning system (PPS of Gamma Knife. A dental impression of patient was created and attached to the frontal piece of extend system. The treatment setup involves positioning the patient within the extend frame using patient specific headrest cushion and front piece. The reference patient’s head position was recorded through measurements of repositioning check tool (RCT apertures using a high precision digital probe before computed tomography (CT scan. The RCT measurements taken before treatment were compared with recorded reference position to ensure appropriate patient treatment position. Volumetric magnetic resonance (MR scan was co-registered with stereotactic CT scan on Leksell Gamma plan. Fused MR to CT images on Gamma Plan was utilized to delineate regions of interest and prepare a precise treatment plan. The presented study includes positional reproducibility check and dosimetric evaluation of ten patients treated with ES.Results: Forty-three fractions on ten patients with prescribed treatment format were delivered successfully. An average tumor volume of 11.26 cm3 (range, 340 mm3 to 59.12 cm3 was treated with ES. The mean tumor coverage of 91.91% (range, 90% to 95% was able to achieve at 50% prescription isodose without compromising adjacent normal structure radiation dose tolerances. The mean inter-fraction positional variation of 0.69 mm influences an inherent strength of immobilization technique. Follow-up of seven patients at a median interval of 16 months (range, 9 months to 26 months showed evidence of 100

  16. An immobilization system for claustrophobic patients in head-and-neck intensity-modulated radiation therapy.

    Kim, Siyong; Akpati, Hilary C; Li, Jonathan G; Liu, Chihray R; Amdur, Robert J; Palta, Jatinder R


    To evaluate the effectiveness of an immobilization treatment system used for claustrophobic patients in head-and-neck intensity-modulated radiation therapy (IMRT). Instead of the thermoplastic facemask, the Vac Fix (S & S Par Scientific, Odense, Denmark) mold is used for immobilization of claustrophobic patients at the University of Florida in head-and-neck IMRT. The immobilization procedure combines the use of commercial stereotactic infrared (IR) ExacTrac camera system (BrainLAB, Inc., Westchester, IL) for patient setup and monitoring. The Vac Fix mold is placed on the headrest and folded up as needed to provide support before the mold is hardened. For the camera system, a frame referred to as a "tattoo-free immobilization accessory" is fabricated, on which the IR markers can be placed. A patient-specific dental impression is made with the bite tray. The movement of the markers, connected through the dental impression of the patient, accurately represents the overall patient motion. Patient movement is continuously monitored and repositioning is performed whenever patient movement exceeds the predefined tolerance limit. Monitored patient movements are recorded at a certain frequency. Recorded data are analyzed and compared with those of patients immobilized with the thermoplastic facemask plus the camera system that is the standard immobilization system in our clinic. For three patients treated with the Vac Fix mold plus the camera system, on average, the histogram-based uncertainties, U(95)(5), U(95)(20), and mean displacement, R(mean) (mm) were 1.03, 1.08, and 0.60, respectively. These values are close to those obtained with the mask plus the camera system. The Vac Fix mold plus the camera system often requires more beam interruptions because of repositioning than the mask plus the camera system (on average, the Vac Fix mold plus the camera system required repositioning 7.7 times and the mask plus the camera system required repositioning 1.8 times during 20

  17. Avaliação de desinfetantes de superfície utilizados em Odontologia Evaluation of surface disinfectants utilized in dentistry

    Célia Regina Gonçalves e Silva


    chlorhexidine. Four surfaces of the equipment were analyzed in the study (the carter, the washbasin for hand-washing, the headrest of the chair and the external surface of the reflector, and the spray-wipe-spray procedure was carried out. From each surface, samples were collected by means of surface plates containing Mitis Salivarius bacitracin sucrose agar, Sabouraud Dextrose agar with chloramphenicol, MacConkey agar and blood agar, for counting mutans streptococci, Candida yeasts, gram-negative bacteria and total microorganisms, respectively (ufc/plate. The results were statistically analyzed by means of the Student's t test in order to compare the mean ufc/plate values. The most effective disinfectant was 77°GL alcohol with 5% of chlorhexidine, mainly against gram-positive bacteria. Iodophor and phenolic compound were also effective in microbial reduction. 77°GL alcohol was the least effective product - however, although it is not considered as a surface disinfectant, it produced, in this study, statistically significant microbial reduction after the disinfecting procedure.

  18. Efeito da rotação da cabeça na pressão intraocular em decúbito ventral: estudo randomizado Efecto de la rotación de la cabeza en la presión intraocular en decúbito ventral: estudio aleatorio The effect of head Rotation on intraocular pressure in prone position: a randomized trial

    M. Nuri Deniz


    ón supina antes del inicio de la operación. Los pacientes fueron posicionados en decúbito ventral. La cabeza fue posicionada sobre un apoyo sin compresión externa directa en ambos ojos. Los pacientes del Grupo I fueron estrictamente mantenidos en pronación neutra, mientras que los pacientes del Grupo II fueron posicionados en pronación con rotación de la cabeza a 45º hacia el lado derecho. Al final de la operación, los pacientes fueron reposicionados en supinación y la PIO fue inmediatamente medida. RESULTADOS: No hubo diferencia entre los datos demográficos, la duración de la cirugía, la pérdida de sangre y la reposición de líquido de los pacientes. Los valores postquirúrgicos de la PIO en decúbito ventral aumentaron significativamente en comparación con los valores preoperatorios en ambos grupos (p BACKGROUND AND OBJECTIVES: The increased intraocular pressure (IOP - which decreases perfusion pressure on the optic nerve - increases by prone positioning (1. The aim of our study was to compare the effect of head rotation 45o laterally in prone position on the increase in IOP of upper placed and lower placed eyes in patients undergoing percutaneous nephrolithotomy (PCNL. METHODS: Forty-five patients were randomly divided into 2 Groups. IOP of the patients were recorded bilaterally in supine position before the operation had started. Patients were turned to prone position. The head was placed on a prone headrest without external direct compression to both eyes. Patients in Group I were kept in strictly neutral prone position where as patients in Group II were placed prone with their heads rotated 45º laterally to the right side. At the end of the operation, patients were turned to supine position and their IOP was measured immediately. RESULTS: There was no difference related to demographics, duration of surgery, blood loss and fluid input data. IOP values after surgery in prone position increased significantly compared to preoperative values in both groups