WorldWideScience

Sample records for delayed flap approach

  1. Energy management - The delayed flap approach

    Science.gov (United States)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  2. Energy management - The delayed flap approach

    Science.gov (United States)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  3. The effect of topical minoxidil pretreatment on nonsurgical delay of rat cutaneous flaps: further studies.

    Science.gov (United States)

    Gümüş, Nazım; Odemiş, Yusuf; Tuncer, Ersin; Yılmaz, Sarper

    2013-08-01

    The purpose of this study was to determine the effectiveness of topically applied minoxidil in the pharmacological delay phenomenon and to demonstrate the comparable microscopic and macroscopic changes between minoxidil-pretreated flaps and surgically delayed flaps. A modified version of the McFarlane flap was used. Group 1 rats, in which a caudally based dorsal skin flap was raised and sutured back, were the control group. In group II, minoxidil solution was spread over the marked skin flap area for 7 days. On the 7th day, a caudally based dorsal skin flap was elevated and then sutured back. Group III rats underwent a surgical delay procedure alone. On the 7th day after flap elevation, evaluation was done by histologic examination and calculation of the flap survival areas in all groups. The lowest flap survival rate appeared in group I and was statistically different from groups II and III. The mean surviving skin flap area in the minoxidil-pretreated group was significantly larger than that in the control group. After histologic evaluation, moderate angiogenesis was also detected in group II. We also found that surgical delay significantly reduced flap necrosis when compared to the minoxidil pretreatment group. According to our study, minoxidil may be considered an effective vasoactive agent for the stimulation of angiogenesis in rat cutaneous flaps and capable of achieving pharmacological delay and increasing flap survival. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

  4. Pretreatment with octreotide modulates iNOS gene expression, mimics surgical delay, and improves flap survival.

    Science.gov (United States)

    Gözü, Aydin; Poda, Mehveş; Taşkin, Elif I; Turgut, Hürriyet; Erginel-Unaltuna, Nihan; Doğruman, Hüsniye; Ozsoy, Zafer

    2010-08-01

    We aimed to evaluate the role of a synthetic somatostatin analogue in delay procedure of experimental skin flaps. Thirty-six rats were randomly divided into 2 groups of 18 each to compare the possible local ischemic effect of octreotide with that of surgical delay in the dorsal random pattern skin flap model. The inducible nitric oxide synthase gene expression was assessed in the flap territory at intervals of immediate, 24 and 48 hours after preconditioning. Histologic analysis was performed in rats at 48th hour and 3 additional rats were used for microangiography. A gradual increase of daily transcript levels was detected in both groups (P < 0.05). The differences of molecular and histologic findings between the groups were not distinctive. Pharmacologically preconditioned rat displayed relevant microvascular features. Forty rats were further grouped randomly into 4 groups of 10 each. In group 1 rats, flaps were raised and reinserted without any prior intervention. Group 2 rats underwent surgical delay procedure, whereas flap territories of the others received either saline solution or octreotide 1 week before the ultimate flap harvest. After another 7-day period, both delay procedures were found effective in improving flap viability (P < 0.01). Ischemia induced by octreotide favored to investigate its utility in delay phenomenon. Although it was not as effective as the surgical delay procedure, it may be a safe pharmacologic alternative to improve the flap survival.

  5. Polidocanol injection for chemical delay and its effect on the survival of rat dorsal skin flaps.

    Science.gov (United States)

    Menevşe, Gülsüm Tetik; TeomanTellioglu, Ali; Altuntas, Nurgül; Cömert, Ayhan; Tekdemir, Ibrahim

    2014-06-01

    Surgical delay is an invasive method requiring a two-stage surgical procedure. Hence, methods that may serve as an alternative to surgical delay have become the focus of interest of research studies. From a conceptual view, any technique that interrupts the blood flow along the edges of a proposed flap will render the flap ischemic and induce a delay phenomenon. Polidocanol (Aethoxysklerol(®)-Kreussler) was initially used as a local anesthetic. Nowadays, it has been used as a sclerosing agent to treat telangiectasias and varicose veins. The aim of this experimental study was to investigate the effects of polidocanol injected around the periphery of a random flap as a sclerosing agent on flap delay and survival in a random flap model. A preliminary histopathologic study was performed on two rats to evaluate the sclerosing effect and distribution of polidocanol injection. After the preliminary study, the main study was carried out with three groups: group 1: dorsal flap (n = 10); group 2: dorsal flap + surgical delay (n = 10), group 3: dorsal flap + chemical delay (n = 10). Tissue samples obtained from the flap and injection area revealed destruction of intradermal vessels. The area affected with sclerosis was limited to 0.1 cm beyond the injection site. Mean viable flap areas were 52.1 ± 4.38% (44.0-58.2) in group 1, 64.8 ± 8.92% (57.2-89.2) in group 2, and 71.8 ± 5.18% (64.0-84.0) in group 3. A statistically highly significant difference was found between the surgical delay and chemical delay groups versus the group without delay (p surgical and chemical delay groups (p = 0.056). In conclusion, this study has shown that polidocanol injection around the dorsal flap in the rat is a safe and easy method for nonsurgical delay. The results have shown a flap survival benefit that is superior to controls and equivalent to surgical delay. The clinical application of polidocanol, already in clinical practice for occlusal of telangiectasias, for surgical delay appears

  6. Value of the post-operative CT in predicting delayed flap failures following head and neck cancer surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bitna; Yoon, Dae Young; Seo, Young Lan; Park, Min Woo; Kwon, Kee Hwan; Rho, Young Soo; Chung, Chul Hoon [Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul (Korea, Republic of)

    2017-06-15

    To identify post-operative computed tomography (CT) findings associated with delayed flap failures following head and neck cancer surgery. We retrospectively reviewed 60 patients who underwent flap reconstruction after head and neck cancer surgery and post-operative (3–14 days) contrast-enhanced CT scans for suspected complications. Patients were divided into two groups: delayed flap failure patients (patients required flap revision) (n = 18) and flap success patients (n = 42). Clinical data (age, sex, T-stage, type of flap, and time interval between reconstruction surgery and CT) and post-operative CT findings of flap status (maximum dimension of the flap, intra- or peri-flap fluid collection and intra- or peri-flap air collection, fat infiltration within the flap, fistula to adjacent aerodigestive tract or skin, and enhanced vascular pedicle) were assessed and compared between the two groups. CT findings showed that the following flap anomalies were observed more frequently in the delayed flap failure group than in the flap success group: intra- or peri-flap fluid collection > 4 cm (61.1% vs. 23.8%, p < 0.05), intra- or peri-flap air collection > 2 cm (61.1% vs. 2.4%, p < 0.001), and fistula to adjacent aerodigestive tract or skin (44.4% vs. 0%, p < 0.001). The maximum dimension of the flap, fat infiltration within the flap, and enhanced vascular pedicle were not associated with delayed flap failures. A large amount of fluid or air collection and fistula are the CT findings that were associated with delayed flap failures in patients with suspected post-operative complications after head and neck cancer surgery.

  7. Preservation of venous outflow improves transverse rectus abdominis musculocutaneous flap survival following vascular delay.

    Science.gov (United States)

    Tsoutsos, D; Gravvanis, A; Kakagia, D; Ghali, S; Papalois, A

    2009-01-01

    The rat abdominal island model has proved to be a reliable and reproducible model for the study of surgical delay procedures. It has been customary to simultaneously divide both the artery and the accompanying vein to obtain maximum survival of the rat TRAM flap undergoing delay procedure. This study evaluates the effect of selective arterial interruption compared to standard vascular delay on flap survival in the rat TRAM flap model. Thirty-six Wistar rats were randomly assigned to three groups (n=12), depending on the vascular ligation selected for the initial experimental delay stage. In group A (control group) no vessels were ligated. In group B the right deep inferior epigastric vessels were preserved and the right superior and left inferior and superior deep vessels were ligated. In group C the right inferior epigastric vessels and the left inferior epigastric vein were preserved while superior epigastric vessels and the left inferior epigastric artery were ligated. For the second stage one week later, TRAM flaps were elevated based on the right deep inferior epigastric vessels, re-inset in their original position and digitally photographed. Skin island viability was determined 96 hours later using digital photography and image-analysis software SigmaScan (SPSS, Inc., Chicago, IL). The percentage of flap survival in control group A was 50+/-6%, in group B 60+/-4% and in group C 85+/-4%. The occlusion of the three vascular pairs in group B improved the survival percentage in comparison to the control group A, but this did not achieve statistical significance. In contrast, the percentage of flap survival in control group C was statistically significant compared to groups A and B (p<0.05, ANOVA). Zone IV exhibited no necrosis in any group C animals. This indicates that delay with preservation of the venous outflow of zone IV results in increased blood supply.

  8. Treatment of delayed jejunal perforation after irreducible femoral hernia repair with open abdomen management and delayed abdominal closure with skin flap approximation

    Directory of Open Access Journals (Sweden)

    Fahri Yetişir

    2015-01-01

    Conclusion: Delayed bowel perforation may develop after irreducible femoral hernia surgery. OA management with NPT and DAC with skin flap approximation are optimal treatment modalities for the hemodynamically instable patient.

  9. Direct delayed breast reconstruction with TAP flap, implant and acellular dermal matrix (TAPIA)

    DEFF Research Database (Denmark)

    Børsen-Koch, Mikkel; Gunnarsson, Gudjon L; Udesen, Ann;

    2015-01-01

    BACKGROUND: The latissimus dorsi (LD) flap is considered one of the working horses within the field of breast reconstruction and it offers several advantages. However, donor-site morbidity may pose a problem. This article describes a new and modified technique for delayed breast reconstruction co...... there is a learning curve, this simple modified technique does not demand any perforator or other vessel dissection. Any trained plastic surgeon should be able to adopt the technique into the growing armamentarium of breast reconstruction possibilities....

  10. Improvement of Upper Extremity Lymphedema after Delayed Breast Reconstruction with an Extended Latissimus Dorsi Myocutaneous Flap

    Directory of Open Access Journals (Sweden)

    Kyeong Tae Lee

    2012-03-01

    Full Text Available Lymphedema is a common complication after mastectomy in breast cancer patients. Many treatment options are available, but no treatment results in a complete cure. We report a case of lymphedema that occurred after modified radical mastectomy in a breast cancer patient who showed objective improvement after delayed breast reconstruction with an latissimus dorsi myocutaneous flap. A 41-year-old female patient with left breast cancer had undergone modified radical mastectomy with axillary lymph node dissection and postoperative radiotherapy 12 years previously. Four years after surgery, lymphedema developed and increased in aggravation despite conservative treatment. Eight years after the first operation, the patient underwent delayed breast reconstruction using the extended latissimus dorsi myocutaneous flap method. After reconstruction, the patient's lymphedema symptoms showed dramatic improvement by subjective measures including tissue softness and feeling of lightness, and by objective measures of about 7 mL per a week, resulting in near normal ranges of volume. At a postoperative follow-up after 3 years, no recurrence was observed. Delayed breast reconstruction with extended latissimus dorsi myocutaneous flaps may be helpful to patients with lymphedema after mastectomy. This may be a good option for patients who are worried about the possibility of the occurrence or aggravation of secondary lymphedema.

  11. The creation of new rotation arc to the rat latissimus dorsi musculo-cutaneous flap with delay procedures

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    Aktas Alper

    2003-12-01

    Full Text Available Abstract Background Latissimus dorsi musculocutaneous flap is one of the most frequently performed reconstructive techniques in surgery. Latissimus dorsi muscle has two arcs of rotation. It is classified as type V muscle. This muscle can be elevated on the thoracodorsal artery to cover large defects in the anterior chest and also, the muscle can be elevated on the segmental vessels to cover midline defects posteriorly. The aim of this study was to create a new arc of rotation on a vertical axis for the muscle and investigate effectiveness of vascular and chemical delays on the latissimus dorsi muscle flap with an inferior pedicle in an experimental rat model. We hypothesized that the latissimus dorsi muscle would be based on inferior pedicle by delay procedures. Methods We tested two different types of delay: vascular and combination of vascular and chemical. We also tried to determine how many days of "delay" can elicit beneficial effects of vascular and combination delays in an inferior pedicled latissimus dorsi musculocutaneous flap. To accomplish this, 48 male Sprague-Dawley rats were randomly subjected to vascular or combination delay (vascular and chemical. In addition, one ear of each rat was assigned into a delay procedure and the other ear was used as a control. Results were evaluated macroscopically, and micro-angiography and histological examinations were also performed. As a result, there was a significant difference in viable flap areas between vascular delay alone and control groups (p Results The higher rate of flap viability was obtained in seven-day vascular delay alone. However, there was no significant difference in the viability between seven-day vascular delay and five-day vascular delay (p Conclusion The combination of vascular and chemical delays increased the rate of viability. Nevertheless, there was no significant difference between vascular delay alone and combination of vascular and chemical delays. Chemical delay did

  12. Improvement of Upper Extremity Lymphedema after Delayed Breast Reconstruction with an Extended Latissimus Dorsi Myocutaneous Flap

    Directory of Open Access Journals (Sweden)

    Kyeong Tae Lee

    2012-03-01

    Full Text Available Lymphedema is a common complication after mastectomy in breast cancer patients. Manytreatment options are available, but no treatment results in a complete cure. We report acase of lymphedema that occurred after modified radical mastectomy in a breast cancerpatient who showed objective improvement after delayed breast reconstruction with anlatissimus dorsi myocutaneous flap. A 41-year-old female patient with left breast cancer hadundergone modified radical mastectomy with axillary lymph node dissection and postoperativeradiotherapy 12 years previously. Four years after surgery, lymphedema developed andincreased in aggravation despite conservative treatment. Eight years after the first operation,the patient underwent delayed breast reconstruction using the extended latissimus dorsimyocutaneous flap method. After reconstruction, the patient’s lymphedema symptomsshowed dramatic improvement by subjective measures including tissue softness and feeling oflightness, and by objective measures of about 7 mL per a week, resulting in near normal rangesof volume. At a postoperative follow-up after 3 years, no recurrence was observed. Delayedbreast reconstruction with extended latissimus dorsi myocutaneous flaps may be helpful topatients with lymphedema after mastectomy. This may be a good option for patients who areworried about the possibility of the occurrence or aggravation of secondary lymphedema.

  13. Una nueva experiencia clínica: Colgajo safeno interno diferido A new clinical experience: the delayed reverse saphenous flap

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    G.A. Wolff I

    2010-12-01

    Full Text Available Los defectos de tejidos blandos de la pierna y el pie cuasados por traumatismos, tumores o infecciones, requieren frecuentemente procedimientos de cobertura mediante el empleo de colgajos. El colgajo safeno interno ha demostrado ser una excelente opción por su versatilidad y su poca morbilidad en el área donante. El diferimiento es un procedimiento útil para reducir las complicaciones vasculares de los colgajos, en pacientes con factores de riesgo añadidos. Su fisiología ha sido estudiada detalladamente, pero aún persisten interrogantes en torno a su uso y al periodo de diferimiento. Presentamos nuestra experiencia clínica con el uso de colgajos diferidos en 2 casos de reconstrucción de pie y tobillo secundarios a traumatismos, en los que se presentó sufrimiento vascular agudo al realizar el colgajo safeno interno reverso. El período de diferimiento varió entre los 7 y los 10 días. Los resultados postoperatorios fueron satisfactorios. Se presentó solo un complicación consistente en necrosis de los bordes de uno de los colgajos (menor del 1%. En conclusión, creemos que el diferimiento de los colgajos regionales es una herramienta útil para reducir la tasa de complicaciones vasculares en los mismos. Nuestra experiencia con el colgajo safeno interno diferido, reportada por primera vez según nuestro conocimiento, confirma la utilidad del procedimiento en este tipo de colgajo, demostrando que aún en condiciones de riesgo vascular esta modificación del colgajo se presenta como una opción alternativa para la reconstrucción exitosa de este tipo de defectos.Complex soft tissue defects of the distal third of the leg and foot represent a challenge in the reconstructive. The internal saphenous flap is a frequently used option for lower leg reconstruction because its versatility and minimal donor site morbidity. The commonly known delay procedure is an alternative. The concept of delay was clearly explained years ago, but still there is

  14. Comparison of ischaemic preconditioning with surgical delay technique to increase the viability of single pedicle island venous flaps: an experimental study.

    Science.gov (United States)

    Ceylan, Refika; Kaya, Burak; Çaydere, Muzaffer; Terzioğlu, Ahmet; Aslan, Gürcan

    2014-12-01

    The aim of the present study was to investigate the effect of ischaemic preconditioning compared with the surgical delay procedure in an effort to increase the survival rate of single pedicle island venous flaps. Eighteen male Wistar albino rats (250-350 g) were included. A 3 × 4 cm flap was planned at the right lower abdomen of the rat. Superficial epigastric vein constituted the pedicle of the flap. The rats were divided into three groups, each consisting of six rats. In the control group, a single pedicle venous island flap was elevated on each rat and no other surgical procedure was performed. In the ischaemic preconditioning group, ischaemic preconditioning was performed and, in the surgical delay procedure group, the surgical delay technique was performed before flap elevation. The mean necrosis areas were 56.85 ± 14.60%, 28.73 ± 15.60%, and 12.08 ± 3.65% in the control, ischaemic preconditioning, and surgical delay procedure groups, respectively. The necrosis areas were significantly smaller in the ischaemic preconditioning group and surgical delay procedure groups compared to the control group (p = 0.004 and p surgical delay procedure groups. Histopathological parameters including necrosis, abscess formation, and skin ulceration scores were significantly lower in the ischaemic preconditioning group than in the control group, whereas the study groups were similar. In conclusion, ischaemic preconditioning may serve as an adjuvant technique in increasing venous island flap viability.

  15. Algorithmic approach to lower abdominal, perineal, and groin reconstruction using anterolateral thigh flaps.

    Science.gov (United States)

    Zelken, Jonathan A; AlDeek, Nidal F; Hsu, Chung-Chen; Chang, Nai-Jen; Lin, Chih-Hung; Lin, Cheng-Hung

    2016-02-01

    Lower abdominal, perineal, and groin (LAPG) reconstruction may be performed in a single stage. Anterolateral thigh (ALT) flaps are preferred here and taken as fasciocutaneous (ALT-FC), myocutaneous (ALT-MC), or vastus lateralis myocutaneous (VL-MC) flaps. We aim to present the results of reconstruction from a series of patients and guide flap selection with an algorithmic approach to LAPG reconstruction that optimizes outcomes and minimizes morbidity. Lower abdomen, groin, perineum, vulva, vagina, scrotum, and bladder wounds reconstructed in 22 patients using ALT flaps between 2000 and 2013 were retrospectively studied. Five ALT-FC, eight ALT-MC, and nine VL-MC flaps were performed. All flaps survived. Venous congestion occurred in three VL-MC flaps from mechanical cause. Wound infection occurred in six cases. Urinary leak occurred in three cases of bladder reconstruction. One patient died from congestive heart failure. The ALT flap is time tested and dependably addresses most LAPG defects; flap variations are suited for niche defects. We propose a novel algorithm to guide reconstructive decision-making.

  16. New Possible Surgical Approaches for the Submammary Adipofascial Flap Based on Its Arterial Supply

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    Ehab M. Elzawawy

    2016-01-01

    Full Text Available Introduction. Submammary adipofascial flap (SMAF is a valuable option for replacement of the inferior portion of the breast. It is particularly useful for reconstruction of partial mastectomy defects. It is also used to cover breast implants. Most surgeons base this flap cranially on the submammary skin crease, reflecting it back onto the breast. The blood vessels supplying this flap are not well defined, and the harvest of the flap may be compromised due to its uncertain vascularity. The aim of the work was to identify perforator vessels supplying SMAF and define their origin, site, diameter, and length. Materials and Methods. The flap was designed and dissected on both sides in 10 female cadavers. SMAF outline was 10 cm in length and 7 cm in width. The flap was raised carefully from below upwards to identify the perforator vessels supplying it from all directions. These vessels were counted and the following measurements were taken using Vernier caliper: diameter, total length, length inside the flap, and distance below the submammary skin crease. Conclusions. The perforators at the lateral part of the flap took origin from the lateral thoracic, thoracodorsal, and intercostal vessels. They were significantly larger, longer, and of multiple origins than those on the medial part of the flap and this suggests that laterally based flaps will have better blood supply, better viability, and more promising prognosis. Both approaches, medially based and laterally based SMAF, carry a better prognosis and lesser chance for future fat necrosis than the classical cranially based flap.

  17. A TRAM flap design refinement for use in delayed breast reconstruction.

    LENUS (Irish Health Repository)

    Patel, A J K

    2009-09-01

    Autologous breast reconstruction following mastectomy is commonly achieved using the free Transverse Rectus Abdominis Myocutaneous (TRAM) flap. Since its first description, refinements and modifications have resulted in improved operative techniques and more aesthetically pleasing reconstructions. Pre-operative flap design, however, is a relatively new concept that has not received much attention in the literature. Patients who undergo breast reconstruction may have large, ptotic contralateral breasts. In these patients there is a tendency to raise a large abdominal flap in an attempt to achieve symmetry, or simply a larger breast. This has the potential to lead to tight closure of the abdomen and the risk of subsequent wound problems. Reconstructions that are too small or have inadequate ptosis commit the patient to contralateral breast surgery to achieve symmetry. Pre-operatively designing the flap, using a template created from the opposite breast, can help achieve a good match, often reducing the need for contralateral breast surgery. Even when contralateral breast reduction surgery is planned in advance, many of these patients still require, and prefer, a large reconstruction in order to achieve a well-proportioned result. We present a design template that addresses these particular issues and in the senior author\\'s hands has proved to be a very effective technique. Our technique allows raising an abdominal flap of less vertical height than traditionally used (thus reducing the risk of tight abdominal closure) and incorporates an inverted V-shaped flap of skin from the inferior mastectomy skin flap into the reconstruction. This allows more flap tissue to be available to fill the upper poles of the reconstructed breast and at the same time produces good ptosis.

  18. Delayed Soft Tissue Reconstruction with a Horizontal Rectus Abdominis Musculocutaneous Flap following Hip Exarticulation

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    Jes Christian Rødgaard

    2013-01-01

    Full Text Available Coverage of large soft tissue defects at the hip region constitutes a challenge for plastic surgeons. We report the case of a 43-year-old female with necrotizing fasciitis of the right thigh, necessitating hip exarticulation and substantial debridement of necrotic tissue. An ipsilateral horizontal rectus abdominis myocutaneous (HRAM flap was used to cover the defect. The reconstruction was carried out after the attempt of local tissue rearrangement. In light of the successful outcome, we propose that this flap be considered in the future planning of soft tissue reconstruction at the hip region.

  19. A Roll Controlling Approach for a Simple Dual-Actuated Flapping Aerial Vehicle Model

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    Labib Omar El-Farouk E.

    2016-01-01

    Full Text Available Aerial vehicles have been investigated recently in different contexts, due to their high potential of utilization in multiple application areas. Different mechanisms can be used for aerial vehicles actuation, such as the rotating multi-blade systems (Multi-Copters and more recently flapping wings. Flapping wing robots have attracted much attention from researchers in recent years. In this study, a simple dual-actuated flapping mechanism is proposed for actuating a flapping wing robot. The mechanism is designed, simulated and validated in both simulation and experiments. A roll controlling approach is proposed to control the roll angle of the robot via controlling the speeds of both motors actuating each of the wings. The results achieved are validated experimentally, and are promising opening the door for further investigation using our proposed system

  20. Preferred use of the ipsilateral pedicled TRAM flap for immediate breast reconstruction: an illustrated approach.

    Science.gov (United States)

    Tan, Bien-Keem; Joethy, Janna; Ong, Yee-Siang; Ho, Gay-Hui; Pribaz, Julian J

    2012-02-01

    Recent experience with the ipsilateral TRAM flap has shown that it has the advantage of a longer functional pedicle length, which allows tension-free inset of well-vascularized tissue into the breast pocket. This leads to better positioning and shaping of the reconstructed breast with minimal disruption of the inframammary fold. The purpose of this article was to provide an illustrated approach to the ipsilateral TRAM flap and to clarify the technique when applied in the context of immediate breast reconstruction following cancer extirpation. A prospective evaluation of 89 patients who underwent immediate breast reconstruction following skin-sparing mastectomy for breast cancer was performed. All patients underwent ipsilateral TRAM reconstruction. The innate insetting advantage of the ipsilateral TRAM flap is illustrated in the article. The key steps of the technique were as follows: (1) The ipsilateral corner of the flap was used as the axillary tail, leaving the more bulky part to form the main body of the breast; (2) To avoid undesirable twists, a right TRAM was rotated clockwise so that its apex points superiorly; (3) This flap was subsequently tunneled into the breast pocket while preserving the inframammary fold. The opposite maneuvers were done for the left side; (4) If the flap was congested, venous augmentation was performed where the tributary of the axillary vein or the thoracodorsal vein was anastomosed with the inferior epigastric vein from the flap with an interposed vein graft (17% of cases). All flaps survived and flap-related complications included partial necrosis of tissue across the midline (2.2%), palpable fat necrosis (22%), and hematoma requiring drainage (2.2%). All flaps were raised concurrent with the resection, and the combined operative time ranged from 3.5 to 6 h, with a mean hospital stay of 7 days. The ipsilateral TRAM flap was a reliable flap with low complication rates and short surgery time. It was our preferred choice for

  1. Delayed buccal fat pad herniation: An unusual complication of buccal flap in cleft surgery

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    Tuli Puneet

    2009-01-01

    Full Text Available Buccal musculomucosal flap is commonly used in cleft palate surgery for providing additional lining when nasal mucosa is inadequate. We report an unusual complication of progressively increasing fat herniation from the sutured donor site which started appearing on the third postoperative day. This necessitated excision of the protruding fat pad on the seventh postoperative day. The possible mechanism and precautions for prevention of this complication are discussed.

  2. Online Delay-Evaluation Approach in Networked Control Systems

    Institute of Scientific and Technical Information of China (English)

    魏震; 马向华; 谢剑英

    2003-01-01

    This paper presents an online evaluation approach of time delays for networked control systems (NCS), which characterizes the time delays without any synchronized clock in the network and any assumptions of time delays. With this approach, an optimal control scheme based on the approach is designed to achieve the desired performance despite the uncertain delays in the system. The experimental results based on CANbus illustrate the effectiveness of the proposed control design and satisfactory performance of the closed-loop system.

  3. Reconstruction of delayed scleral flap melting with bovine pericardium after trabeculectomy with mitomycin C

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    Coutinho, Inês

    2017-06-01

    Full Text Available Aim: To present a challenging case of hypotony after trabeculectomy and its treatment. Case description: A 22-year-old woman with juvenile glaucoma underwent a conventional trabeculectomy with mitomycin C on the right eye (OD. In the immediate postoperative period, we observed a hyperfiltration bleb with hypotony refractory to conservative measures leading to hypotony maculopathy.A surgical revision with scleral flap resuture and conjunctival graft was performed with a satisfactory result and resolution of hypotony maculopathy. After two years, the patient complained of low visual acuity (VA of the OD. During examination, we observed a fine and avascular bleb with Seidel and visualization of the underlying uveal tissue, an intraocular pressure (IOP of 5 mmHg, and chorioretinal folds. A new revision of the trabeculectomy was performed. During the procedure, it was not possible to identify the scleral flap, so the fistula was closed with a patch of collagenous membrane derived from bovine pericardium (Tutopatch graft. A good clinical evolution occurred. After 2 months, IOP was 15 mmHg without Seidel or changes in the fundus and VA was 20/20. After of follow-up, the IOP remains stable without further complaints. Conclusion: This case illustrates the difficulties faced in the management of a common complication of trabeculectomy and highlights some of the options available for its treatment. There are few reports of scleral melting after trabeculectomy. However, trauma and scleral necrosis associated with mitomycin are listed as the main causes.The use of a scleral patch derived from bovine pericardium allows effective suturing and closure of the aqueous leak.

  4. Delay-range-dependent chaos synchronization approach under varying time-lags and delayed nonlinear coupling.

    Science.gov (United States)

    Zaheer, Muhammad Hamad; Rehan, Muhammad; Mustafa, Ghulam; Ashraf, Muhammad

    2014-11-01

    This paper proposes a novel state feedback delay-range-dependent control approach for chaos synchronization in coupled nonlinear time-delay systems. The coupling between two systems is esteemed to be nonlinear subject to time-lags. Time-varying nature of both the intrinsic and the coupling delays is incorporated to broad scope of the present study for a better-quality synchronization controller synthesis. Lyapunov-Krasovskii (LK) functional is employed to derive delay-range-dependent conditions that can be solved by means of the conventional linear matrix inequality (LMI)-tools. The resultant control approach for chaos synchronization of the master-slave time-delay systems considers non-zero lower bound of the intrinsic as well as the coupling time-delays. Further, the delay-dependent synchronization condition has been established as a special case of the proposed LK functional treatment. Furthermore, a delay-range-dependent condition, independent of the delay-rate, has been provided to address the situation when upper bound of the delay-derivative is unknown. A robust state feedback control methodology is formulated for synchronization of the time-delay chaotic networks against the L2 norm bounded perturbations by minimizing the L2 gain from the disturbance to the synchronization error. Numerical simulation results are provided for the time-delay chaotic networks to show effectiveness of the proposed delay-range-dependent chaos synchronization methodologies. Copyright © 2014 ISA. Published by Elsevier Ltd. All rights reserved.

  5. Delay Computation Using Fuzzy Logic Approach

    Directory of Open Access Journals (Sweden)

    Ramasesh G. R.

    2012-10-01

    Full Text Available The paper presents practical application of fuzzy sets and system theory in predicting delay, with reasonable accuracy, a wide range of factors pertaining to construction projects. In this paper we shall use fuzzy logic to predict delays on account of Delayed supplies and Labor shortage. It is observed that the project scheduling software use either deterministic method or probabilistic method for computation of schedule durations, delays, lags and other parameters. In other words, these methods use only quantitative inputs leaving-out the qualitative aspects associated with individual activity of work. The qualitative aspect viz., the expertise of the mason or the lack of experience can have a significant impact on the assessed duration. Such qualitative aspects do not find adequate representation in the Project Scheduling software. A realistic project is considered for which a PERT chart has been prepared using showing all the major activities in reasonable detail. This project has been periodically updated until its completion. It is observed that some of the activities are delayed due to extraneous factors resulting in the overall delay of the project. The software has the capability to calculate the overall delay through CPM (Critical Path Method when each of the activity-delays is reported. We shall now demonstrate that by using fuzzy logic, these delays could have been predicted well in advance.

  6. Double Back Cut in Post-mastectomy Breast Skin (Fish-Shaped Skin Paddle) in Delayed Pedicled TRAM Flap Breast Reconstruction.

    Science.gov (United States)

    Berezovsky, Alexander Bogdanov; Pagkalos, Vasileios A; Shoham, Yaron; Krieger, Yuval; Silberstein, Eldad

    2015-08-01

    Breast reconstruction has become standard of care for female patients with breast cancer. The transverse rectus abdominis musculo-cutaneous flap (TRAMf) is the most common method of immediate or delayed autologous breast reconstruction following mastectomy. We share our experience with modified, double back cut of post-mastectomy skin in delayed pedicled TRAMf breast reconstruction, resulting in fish-shaped skin paddle. This sort of back cut is a simple, reliable way to obtain a natural, esthetically pleasant breast mound with inconspicuous hidden scars.

  7. A novel approach to delay-fractional-dependent stability criterion for linear systems with interval delay.

    Science.gov (United States)

    An, Jiyao; Li, Zhiyong; Wang, Xiaomei

    2014-03-01

    This paper considers the problem of delay-fractional-dependent stability analysis of linear systems with interval time-varying state delay. By developing a delay variable decomposition approach, both the information of the variable dividing subinterval delay, and the information of the lower and upper bound of delay can be taken into full consideration. Then a new delay-fractional-dependent stability criterion is derived without involving any direct approximation in the time-derivative of the Lyapunov-Krasovskii (LK) functional via some suitable Jensen integral inequalities and convex combination technique. The merits of the proposed result lie in less conservatism, which are realized by choosing different Lyapunov matrices in the variable delay subintervals and estimating the upper bound of some cross term in LK functional more exactly. At last, two well-known numerical examples are employed to show the effectiveness and less conservatism of the proposed method.

  8. Pre-expanded occipito-dorsal flap reconstruction for neck burns: A novel approach

    Directory of Open Access Journals (Sweden)

    Sameena Hassan

    2014-04-01

    Full Text Available Reconstruction of the neck following a burn injury poses a significant challenge to reconstructive burn surgeons. Here, we report a case of successful application of pre-expanded occipito-dorsal flaps in the reconstruction of postburn scars and contractures in the neck. The patient was a 10-year-old boy who sustained scars and contractures secondary to a burn injury 4 years ago. "Super-thin" flaps were obtained through pre-expansion in the occipito-dorsal area and then transferred to the recipient site. This approach resulted in an esthetic satisfaction and a significant functional improvement, thereby having significant clinical implications in the reconstruction of soft tissue damage secondary to burn injuries in the neck.

  9. Use of the Fix and Flap Approach to Complex Open Elbow Injury: The Role of the Free Anterolateral Thigh Flap

    Directory of Open Access Journals (Sweden)

    Christopher Hoe-Kong Chui

    2012-03-01

    Full Text Available Background Complex elbow injuries with associated nerve, muscle, or joint injury commonlydevelop post-inury stiffness. In order to preserve function, joint congruency, elbow stabilityand durable wound coverage must be achieved in a timely manner.Methods A retrospective review of patients who underwent orthopaedic fixation followedby free anterolateral thigh (ALT flap soft tissue coverage was performed. Five patients wereidentified and included in this study.Results We present a series of 5 cases managed with this principle. Soft tissue defects rangedin size from 4×9 cm (36 cm2 to 15×30 cm (450 cm2 and were located either posteriorly(n=4 or anteriorly (n=1. Associated injuries included open fractures (n=3 and motor nervetransection (n=2. Wound coverage was achieved in a mean duration of 18.8 days (range, 11to 42 day. There were no flap failures and no major complications. The mean postoperativeactive elbow motion was 102° (range, 45° to 140°.Conclusions In our small series we have highlighted the safety and utility of using the freeALT flap in complex elbow injuries. The ALT flap has many advantages which include abundantskin and subcutaneous tissue; vascularised vastus lateralis muscle that was used in our seriesto obliterate dead space, provide a vascular bed for nerve grafts and combat infection; and,access to fascia lata grafts for reconstruction of the triceps tendon.

  10. Aerodynamic Analysis of Flexible Flapping Wing Micro Aerial Vehicle Using Quasi-Steady Approach

    Science.gov (United States)

    Vijayakumar, Kolandapaiyan; Chandrasekhar, Uttam; Chandrashekhar, Nagaraj

    2016-10-01

    In recent times flexible flapping-wing aerodynamics has generated a great deal of interest and is the topic of contemporary research because of its potential application in micro aerial vehicles (MAVs). The prominent features of MAVs include low Reynolds Number, changing the camber of flapping wings, development of related mechanisms, study of the suitability airfoil shape selection and other parameters. Generally, low Reynolds Number is similar to that of an insect or a bird (103-105). The primary goal of this project work is to perform CFD analysis on flexible flapping wing MAVs in order to estimate the lift and drag by using engineering methods such as quasi-steady approach. From the wind tunnel data, 3-D deformation is obtained. For CFD analysis, two types of quasi-steady methods are considered. The first method is to slice the wing section chord-wise and span wise at multiple regions, frame by frame, and obtain the 2-D corrugated camber section for each frame. This 2-D corrugated camber is analysed using CFD techniques and all the individual 2-D corrugated camber results are summed up frame by frame, to obtain the total lift and drag for one wing beat. The second method is to consider the 3D wing in entirety and perform the CFD analysis to obtain the lift and drag for five wing beat.

  11. Radiation-Induced Leiomyosarcoma after Breast Cancer Treatment and TRAM Flap Reconstruction

    Directory of Open Access Journals (Sweden)

    M. Olcina

    2008-01-01

    We present a case of leiomyosarcoma in a patient who underwent mastectomy followed by radiotherapy for invasive ductal carcinoma. A delayed TRAM flap reconstruction was performed 10 years after and a rapid growing mass under the reconstructed flap appeared, on routine follow-up, twenty years later. This report analyzes the diagnostic and therapeutic approach of patients with RIS.

  12. Online Scheduling in Manufacturing A Cumulative Delay Approach

    CERN Document Server

    Suwa, Haruhiko

    2013-01-01

    Online scheduling is recognized as the crucial decision-making process of production control at a phase of “being in production" according to the released shop floor schedule. Online scheduling can be also considered as one of key enablers to realize prompt capable-to-promise as well as available-to-promise to customers along with reducing production lead times under recent globalized competitive markets. Online Scheduling in Manufacturing introduces new approaches to online scheduling based on a concept of cumulative delay. The cumulative delay is regarded as consolidated information of uncertainties under a dynamic environment in manufacturing and can be collected constantly without much effort at any points in time during a schedule execution. In this approach, the cumulative delay of the schedule has the important role of a criterion for making a decision whether or not a schedule revision is carried out. The cumulative delay approach to trigger schedule revisions has the following capabilities for the ...

  13. A MEDICAL APPROACH TO LANGUAGE DELAY

    African Journals Online (AJOL)

    Enrique

    Language prob- lems interfere with a child's ability to communicate effectively, both in the expres- ... embodied in different specialists, making a team approach appropriate. Doctors need to ..... Management of expressive ... A modified teaching.

  14. AN ANALYTIC APPROACH TO THEORETICAL MODELING OF HIGHLY UNSTEADY VISCOUS FLOW EXCITED BY WING FLAPPING IN SMALL INSECTS

    Institute of Scientific and Technical Information of China (English)

    余永亮; 童秉纲; 马晖扬

    2003-01-01

    Numerous studies on the aerodynamics of insect wing flapping were carried out on different approaches of flight investigations, model experiments, and numerical simulations, but the theoretical modeling remains to be explored. In the present paper, an analytic approach is presented to model the flow interactions of wing flapping in air for small insects with the surrounding flow fields being highly unsteady and highly viscous. The model of wing flapping is a 2-D flat plate, which makes plunging and pitching oscillations as well as quick rotations reversing its positions of leading and trailing edges, respectively, during stroke reversals. It contains three simplified aerodynamic assumptions:(i) unsteady potential flow; (ii) discrete vortices shed from both leading and trailing edges of the wing; (iii) Kutta conditions applied at both edges. Then the problem is reduced to the solution of the unsteady Laplace equation, by using distributed singularities, i.e., sources/sinks, and vortices in the field. To validate the present physical model and analytic method proposed via benchmark examples, two elemental motions in wing flapping and a case of whole flapping cycles are analyzed,and the predicted results agree well with available experimental and numerical data. This verifies that the present analytical approach may give qualitatively correct and quantitatively reasonable results.Furthermore, the total fluid-dynamic force in the present method can be decomposed into three parts:one due to the added inertial (or mass) effect, the other and the third due to the induction of vortices shed from the leading- and the trailing-edge and their images respectively, and this helps to reveal the flow control mechanisms in insect wing flapping.

  15. Robust design of multiple trailing edge flaps for helicopter vibration reduction: A multi-objective bat algorithm approach

    Science.gov (United States)

    Mallick, Rajnish; Ganguli, Ranjan; Seetharama Bhat, M.

    2015-09-01

    The objective of this study is to determine an optimal trailing edge flap configuration and flap location to achieve minimum hub vibration levels and flap actuation power simultaneously. An aeroelastic analysis of a soft in-plane four-bladed rotor is performed in conjunction with optimal control. A second-order polynomial response surface based on an orthogonal array (OA) with 3-level design describes both the objectives adequately. Two new orthogonal arrays called MGB2P-OA and MGB4P-OA are proposed to generate nonlinear response surfaces with all interaction terms for two and four parameters, respectively. A multi-objective bat algorithm (MOBA) approach is used to obtain the optimal design point for the mutually conflicting objectives. MOBA is a recently developed nature-inspired metaheuristic optimization algorithm that is based on the echolocation behaviour of bats. It is found that MOBA inspired Pareto optimal trailing edge flap design reduces vibration levels by 73% and flap actuation power by 27% in comparison with the baseline design.

  16. The suprameatal dural flap for superior petrosal vein protection during the retrosigmoid intradural suprameatal approach.

    Science.gov (United States)

    Mortini, Pietro; Gagliardi, Filippo; Boari, Nicola; Spina, Alfio; Bailo, Michele; Franzin, Alberto

    2014-01-01

    The drilling of the suprameatal bone during the retrosigmoid intradural suprameatal approach (RISA) puts the superior petrosal vein complex at risk of heating and mechanical injury, which may lead to cerebellar swelling and infarction. We present a new technique to protect the superior petrosal venous complex during suprameatal bone drilling. A microanatomical laboratory investigation on cadaver was conducted. The surgical technique is described and intraoperative schematic pictures are provided. The surgical steps of this technique and the related intraoperative images are reported. One case illustration regarding the removal of a large petrous apex meningioma with Meckel cave extension is described to demonstrate the application of the technique in a clinical setting. Reflecting a dural flap onto the posterior trigeminal nerve root and the superior petrosal vein complex can be a simple way to protect the nerve and the vein during the suprameatal bone drilling during the RISA. Georg Thieme Verlag KG Stuttgart · New York.

  17. Impact of delayed implant and DIEP flap breast reconstruction on body image and sexual satisfaction: a prospective follow-up study.

    Science.gov (United States)

    Gopie, Jessica P; ter Kuile, Moniek M; Timman, Reinier; Mureau, Marc A M; Tibben, Aad

    2014-01-01

    Prospective studies regarding the psychosexual impact after different types of breast reconstruction (BR) are scarce. The impact of either implant or deep inferior epigastric artery perforator (DIEP) flap BR on body image and sexual relationship satisfaction was investigated in time. At baseline, 98 women opting for delayed implant or DIEP flap BR after mastectomy for breast cancer completed a survey. The majority was followed up at 6 months (96%) and 20 months (86%) postoperatively. Questionnaires included the body image scale, Dutch Relationship Questionnaire, Short Form - 36 Health Survey and the Impact of Event Scale. Mixed modeling analyses indicated that preoperative body image improved significantly after 20 months (p body image was related to a better general mental health (p = 0.02), less cancer distress (p Body image and sexual relationship satisfaction significantly improved after BR, and this was not related to the BR type. Psychosexual consequences from previous cancer treatment may interfere. Lower general mental health, higher cancer distress, less partner relationship satisfaction or receiving hormonal therapy can negatively affect body image or sexual relationship satisfaction. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Reconfigurable diplexer based on switched delay line approach

    DEFF Research Database (Denmark)

    Zhurbenko, Vitaliy; Acar, Öncel; Ruaro, Andrea;

    2013-01-01

    In this work, a concept for the realization of a reconfigurable microwave multiplexer based on a switched delay-line topology is presented. The multiplexing concept is studied by considering a diplexer example. The topology provides two times reduction in the number of filters in comparison...... to the conventional directional filter approach. The switched delay-line topology enables the lossy and nonlinear switching elements to be used as a part of the coupling elements rather than within the resonators. Therefore, the diplexer potentially allows for a low insertion loss and high linearity. In addition...

  19. Combined supra-transorbital keyhole approach for treatment of delayed intraorbital encephalocele: A minimally invasive approach for an unusual complication of decompressive craniectomy

    Directory of Open Access Journals (Sweden)

    Lucia di Somma

    2016-01-01

    Conclusions: The peculiarities of this case are the orbital encephalocele without an orbital roof traumatic fracture, and the combined minimally invasive approach used to fix both the encephalocele and the orbital roof defect. Delayed intraorbital encephalocele is probably a complication related to an unintentional opening of the orbit during decompressive craniectomy through which the brain herniated following the restoration of physiological intracranial pressure gradients after the bone flap repositioning. The reconstruction of the orbital roof was performed by using a combined supra-transorbital minimally invasive approach aiming at achieving adequate surgical exposure while preserving the autologous cranioplasty, already osteointegrated. To the best of our knowledge, this approach has not been previously used to address intraorbital encephalocele.

  20. Postburn neck anterior contracture treatment in children with scar-fascial local trapezoid flaps: a new approach.

    Science.gov (United States)

    Grishkevich, Viktor M; Grishkevich, Max; Menzul, Vasiliy

    2015-01-01

    One of the dramatic consequences of burns is scar contracture and deformities of the neck. Cervical contracture in children is especially dangerous, leading to face disfigurement and kyphosis; therefore, early reconstruction is indicated. Despite the existence of many various surgical techniques, the successful neck contracture treatment in pediatric patients remains a challenge for surgeons. Eleven children (aged 5 to 14 years) with postburn neck anterior contractures were studied to develop a new approach for reconstruction that would employ the use of local scar-fascial flaps. The new approach and technique for postburn pediatric contracture treatment was developed which is especially effective in the treatment of children who cannot undergo complex and long surgical procedures that are aimed at both contracture elimination and neck skin restoration. The technique consists of two trapezoid scar-fascial flaps mobilization which includes all the anterior neck surfaces and consists of scars, fat layer, platysma, and deep cervical fascia. Counter transposition of flaps with tension elongated neck anterior surface was 100 to 200%. The contracture was fully eliminated, and neck contours, mentocervical angle, and head movement were restored. In case of severe contracture, residual wound in submandibular region and above clavicles were skin-grafted. The full range of head motion (functional results) was achieved in all the 11 patients. The flaps continued to grow and the skin grafts shrinkage was moderate. Local trapeze-flap plasty allows neck contracture elimination in children in the cases when a more complex technique is impossible or undesirable to use. Early surgical intervention prevents secondary complications, allotting enough time for patients to mature and be ready for more complex procedures.

  1. Radio-anatomical analysis of the pericranial flap "money box approach" for ventral skull base reconstruction.

    Science.gov (United States)

    Santamaría, Alfonso; Langdon, Cristóbal; López-Chacon, Mauricio; Cordero, Arturo; Enseñat, Joaquim; Carrau, Ricardo; Bernal-Sprekelsen, Manuel; Alobid, Isam

    2017-03-21

    To evaluate the versatility of the pericranial flap (PCF) to reconstruct the ventral skull base, using the frontal sinus as a gate for its passage into the sinonasal corridor "money box approach." Anatomic-radiological study and case series. Various approaches and their respective defects (cribriform, transtuberculum, clival, and craniovertebral junction) were completed in 10 injected specimens. The PCF was introduced into the nose through the uppermost portion of the frontal sinus (money box approach). Computed tomography (CT) scans (n = 50) were used to measure the dimensions of the PCF and the skull base defects. The vertical projection of the external ear canal was used as the reference point to standardize the incisions for the PCF. The surface area and maximum length of the PCF were 121.5 ± 19.4 cm(2) and 18.3 ± 1.3 cm, respectively. Using CT scans, we determined that to reconstruct defects secondary to transcribriform, transtuberculum, clival, and craniovertebral approaches, the PCF distal incision must be placed respectively at -3.7 ± 2.0 cm (angle -17.4 ± 8.5°), -0.2 ± 2.0 cm (angle -1.0 ± 9.3°), +5.5 ± 2.3 cm (angle +24.4 ± 9.7°), +8.4 ± 2.4 cm (angle +36.6 ± 11.5°), as related to the reference point. Skull base defects in our clinical cohort (n = 6) were completely reconstructed uneventfully with the PCF. The PCF renders enough surface area to reconstruct all possible defects in the ventral and median skull base. Using the uppermost frontal sinus as a gateway into the nose (money box approach) is feasible and simple. NA Laryngoscope, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  2. Approach to Mental Retardation and Global Developmental Delay

    Directory of Open Access Journals (Sweden)

    Mahmoud Reza ASHRAFI

    2011-04-01

    Full Text Available ObjectiveMental Retardation (MR or Intellectual Disability is one of three chronic and disabling neurological disorders of children and adolescents. Its prevalence is estimated 1-3% of the population. MR is defined as significant sub-average intellectual functioning and adaptive behavior that become detectable before the age of 18. MR may come into view before 5 years as delay in at least two developmental domains which is called Global Developmental Delay (GDD.The causes of mental retardation can be considered under the titles of prenatal, perinatal and postnatal factors. Prenatal causes account for approximately 60 -80 % of the etiological factors. All patients with GDD / MR should undergo a stepwise diagnostic approach, because a specific diagnosis leads to opportunity for treatment, future planning and genetic counseling. History, physical examination and neurodevelopmental examinations are the most important parts of the approach. Recent advances in cytogenetic investigations and neuroimaging studies have led to recognition of new disorders and improvement of the diagnostic yield.Keywords: Mental retardation ; global developmental delay; diagnostic yield.

  3. Pedicled perforator flaps

    DEFF Research Database (Denmark)

    Demirtas, Yener; Ozturk, Nuray; Kelahmetoglu, Osman;

    2009-01-01

    Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap to recon......Described in this study is a surgical concept that supports the "consider and use a pedicled perforator flap whenever possible and indicated" approach to reconstruct a particular skin defect. The operation is entirely free-style; the only principle is to obtain a pedicled perforator flap...... more practical and creative to use a free-style manner during pedicled perforator flap surgery, instead of being obliged to predefined templates for this type of procedure....

  4. Fokker-Planck approach to stochastic delay differential equations

    Science.gov (United States)

    Guillouzic, Steve

    2001-10-01

    Models written in terms of stochastic delay differential equations (SDDE's) have recently appeared in a number of fields, such as physiology, optics, and climatology. Unfortunately, the development of a Fokker-Planck approach for these equations is being hampered by their non-Markovian nature. In this thesis, an exact Fokker- Planck equation (FPE) is formulated for univariate SDDE's involving Gaussian white noise. Although this FPE is not self-sufficient, it is found to be helpful in at least two different contexts: with a short delay approximation and under an appropriate separation of time scales. In the short delay approximation, a Taylor expansion is applied to an SDDE with nondelayed diffusion and yields a nondelayed stochastic differential equation. The aforementioned FPE then allows the derivation of an alternate and complementary approximation of the original SDDE. This method is illustrated with linear and logistic SDDE's. Under the separation of time scales assumption, the FPE of a bistable system is reduced to a form that is uniquely determined by the steady-state probability density when the diffusion term of the SDDE is nondelayed. In the context of an overdamped particle with delayed coupling to a symmetrical and stochastically driven potential, the resulting FPE is used with standard techniques to express the transition rate between wells in terms of the noise amplitude and of the steady-state probability density. The same is also accomplished for the mean first passage time from one point to another. This whole approach is then applied to the case of a quartic potential, for which all realisations eventually stabilise on an oscillatory trajectory with an ever increasing amplitude. Although this latter phenomenon prevents the existence of a steady-state limit, a pseudo- steady-state probability density can be defined and used instead of the non-existent steady-state one when the transition rate to these unbounded oscillatory trajectories is

  5. Metatarsal Reconstruction with a Fibular Osteocutaneous Flap: A Novel Approach Utilizing Virtual Surgical Planning

    Directory of Open Access Journals (Sweden)

    Hugo St. Hilaire, MD, DDS

    2014-11-01

    Full Text Available Summary: Craniofacial reconstruction remains the main application for virtual surgical planning (VSP. We present a case in which this technology was applied to reconstruct a bony defect of the first metatarsal bone from a gunshot injury. VSP was used to facilitate a 1-stage reconstruction with a fibular osteocutaneous flap. A template of the reconstructed bone was designed based on the virtual mirror-image, noninjured bone. Prefabricated cutting guides facilitated precise shaping of the vascularized bone accounting for location of perforators. Successful reconstruction of the metatarsal bone was achieved with excellent functional outcomes. We believe that VSP can be a valuable tool in reconstruction of metatarsal bones by facilitating precise intraoperative shaping and anatomic orientation of the vascularized flap and reducing flap ischemia and operative time.

  6. Reliable Force Predictions for a Flapping-wing Micro Air Vehicle : A "Vortex-lift" Approach

    NARCIS (Netherlands)

    Thielicke, W.; Kesel, A. B.; Stamhuis, Eize

    2011-01-01

    Vertical and horizontal force of a flapping-wing micro air vehicle (MAV) has been measured in slow-speed forward flight using a force balance. Detailed information on kinematics was used to estimate forces using a blade-element analysis. Input variables for this analysis are lift and drag coefficien

  7. A delay-range-partition approach to analyse stability of linear systems with time-varying delays

    Science.gov (United States)

    Xue, Y.; Zhang, X.; Han, Y. Y.; Shi, M.

    2016-12-01

    In this paper, the stability analysis of linear systems with an interval time-varying delay is investigated. First, augmented Lyapunov-Krasovskii functionals are constructed, which include more information of the delay's range and the delay's derivative. Second, two improved integral inequalities, which are less conservative than Jensen's integral inequalities, and delay-range-partition approach are utilised to estimate the upper bounds of the derivatives of the augmented Lyapunov-Krasovskii functionals. Then, less conservative stability criteria are proposed no matter whether the lower bound of delay is zero or not. Finally, to illustrate the effectiveness of the stability criteria proposed in this paper, two numerical examples are given and their results are compared with the existing results.

  8. 兔延迟术后脂肪瓣内间充质干细胞增殖的实验研究%Proliferation of the mesenchymal stem cells in a delayed fat flap: an experimental study in rabbits

    Institute of Scientific and Technical Information of China (English)

    江素君; 何晓升; 倪有娣; 刘茂林; 刘苏杭; 钟晓春

    2009-01-01

    Objective To investigate the possibility to enhance the proliferation of adipose-derived stem cells (ASCs) in a delayed fat flap in rabbits. Methods A delayed fat flap was formed in one side of inguinal region of a rabbit. 21 days after operation, the fat tissues at the delayed flaps and at the unoperated side were harvested and digested with 0.25% collageusse and sieved. The cell suspensions were centrifuged. The cells were obtained from tissue precipitate after centrifugation. The expression rates of the surface marker (CD29 CD44,CD14 and CD45) were measured by FCM and compared between the experimental and control groups. Results Expression rates of CD29 and CD44 were higher in the delayed fat flap (74.06% and 90.74%) than in the eontralateral fat tissue (62.88% and 77.54%, P < 0.05), while those of CD14 and CD45 were lower in the delayed fat flap (57.66% and 4.84%) than in the eontralateral fat tissue (72.10% and 75.82%, P < 0.05 and P < 0.01). Conclusions Tissue hypoxic isehemia such as fat tissue in a delayed fat flap can promote proliferation of ASCs. It indicates that tissue in the delayed flap may be transplanted with better survival rate. The ischemia pretreatement of fat tissue may become a new method for fat transplantion.%目的 探讨采用脂肪瓣延迟术等缺血缺氧的方法,促使脂肪来源的兔间充质干细胞(ASCs)增殖的可能性.方法 以兔为动物模型,在一侧腹股沟处形成脂肪瓣.21 d后取出瓣内脂肪组织及对侧正常脂肪组织,消化过筛离心,收集离心后沉淀物中的细胞,用流式细胞仪检测细胞的表面标记,计算细胞CD29、CD44、CD14和CD45的表达率并进行组间比较.结果 脂肪瓣延迟术后,瓣内细胞CD29和CD44的表达率增加,分别为74.06%和90.74%,未经处理的对侧脂肪组织分别为62.88%和77.54%,差异有统计学意义(P<0.05);瓣内细胞CD14和CD45的表达率减少,分别为57.66%和4.84%,未经处理的对侧脂肪组织分别为72.10%和75.82%,

  9. Delayed feedback control of time-delayed chaotic systems: Analytical approach at Hopf bifurcation

    Energy Technology Data Exchange (ETDEWEB)

    Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Sedigh, Ali Khaki [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)

    2008-07-28

    This Letter is concerned with bifurcation and chaos control in scalar delayed differential equations with delay parameter {tau}. By linear stability analysis, the conditions under which a sequence of Hopf bifurcation occurs at the equilibrium points are obtained. The delayed feedback controller is used to stabilize unstable periodic orbits. To find the controller delay, it is chosen such that the Hopf bifurcation remains unchanged. Also, the controller feedback gain is determined such that the corresponding unstable periodic orbit becomes stable. Numerical simulations are used to verify the analytical results.

  10. Variable sampling approach to mitigate instability in networked control systems with delays.

    Science.gov (United States)

    López-Echeverría, Daniel; Magaña, Mario E

    2012-01-01

    This paper analyzes a new alternative approach to compensate for the effects of time delays on a dynamic networked control system (NCS). The approach is based on the use of time-delay-predicted values as the sampling times of the NCS. We use a one-step-ahead prediction algorithm based on an adaptive time delay neural network. The application of pole placement and linear quadratic regulator methods to compute the feedback gains taking into account the estimated time delays is investigated.

  11. Linear delay-differential systems with commensurate delays an algebraic approach

    CERN Document Server

    Gluesing-Luerssen, Heide

    2002-01-01

    The book deals with linear time-invariant delay-differential equations with commensurated point delays in a control-theoretic context. The aim is to show that with a suitable algebraic setting a behavioral theory for dynamical systems described by such equations can be developed. The central object is an operator algebra which turns out to be an elementary divisor domain and thus provides the main tool for investigating the corresponding matrix equations. The book also reports the results obtained so far for delay-differential systems with noncommensurate delays. Moreover, whenever possible it points out similarities and differences to the behavioral theory of multidimensional systems, which is based on a great deal of algebraic structure itself. The presentation is introductory and self-contained. It should also be accessible to readers with no background in delay-differential equations or behavioral systems theory. The text should interest researchers and graduate students.

  12. White Roll Vermilion turn down flap in primary unilateral cleft lip repair: A novel approach

    Directory of Open Access Journals (Sweden)

    R K Mishra

    2015-01-01

    Full Text Available Aim: Numerous modifications of Millard′s technique of rotation - advancement repair have been described in literature. This article envisions a new modification in Millard′s technique of primary unilateral chieloplasty. Material and Methods: Eliminating or reducing the secondary deformities in children with cleft lip has been a motivating factor for the continual refinement of cleft lip surgical techniques through the years. Vermilion notching, visibility of paramedian scars and scar contracture along the white roll are quite noticeable in close-up view even in good repairs. Any scar is less noticeable if it is in midline or along the lines of embryological closure. White Roll Vermilion turn down Flap (WRV Flap, a modification in the Millard′s repair is an attempt to prevent these secondary deformities during the primary cleft lip sugery. This entails the use of white roll and the vermilion from the lateral lip segment for augmenting the medial lip vermilion with the final scar in midline at the vermilion. Result: With an experience of more than 100 cases of primary cleft lip repair with this technique, we have achieved a good symmetry and peaking of cupid′s bow with no vermilion notching of the lips. Conclusion: WRV flap aims to high light the importance of achieving a near normal look of the cleft patient with the only drawback of associated learning curve with this technique.

  13. Parametric study of fluid flow manipulation with piezoelectric macrofiber composite flaps

    Science.gov (United States)

    Sadeghi, O.; Tarazaga, P.; Stremler, M.; Shahab, S.

    2017-04-01

    Active Fluid Flow Control (AFFC) has received great research attention due to its significant potential in engineering applications. It is known that drag reduction, turbulence management, flow separation delay and noise suppression through active control can result in significantly increased efficiency of future commercial transport vehicles and gas turbine engines. In microfluidics systems, AFFC has mainly been used to manipulate fluid passing through the microfluidic device. We put forward a conceptual approach for fluid flow manipulation by coupling multiple vibrating structures through flow interactions in an otherwise quiescent fluid. Previous investigations of piezoelectric flaps interacting with a fluid have focused on a single flap. In this work, arrays of closely-spaced, free-standing piezoelectric flaps are attached perpendicular to the bottom surface of a tank. The coupling of vibrating flaps due to their interacting with the surrounding fluid is investigated in air (for calibration) and under water. Actuated flaps are driven with a harmonic input voltage, which results in bending vibration of the flaps that can work with or against the flow-induced bending. The size and spatial distribution of the attached flaps, and the phase and frequency of the input actuation voltage are the key parameters to be investigated in this work. Our analysis will characterize the electrohydroelastic dynamics of active, interacting flaps and the fluid motion induced by the system.

  14. A novel stability criterion for interval time-delay chaotic systems via the evolutionary programming approach

    Energy Technology Data Exchange (ETDEWEB)

    Yan, J.-J. [Department of Computer and Communication, Shu-Te University, Kaohsiung 824, Taiwan (China)]. E-mail: jjyan@mail.stu.edu.tw; Hung, M.-L. [Department of Electrical Engineering, Far-East College, No. 49, Jung-Haw Road, Hsin-Shih Town, Tainan 744, Taiwan (China)

    2006-09-15

    This paper investigates a novel stability criterion for interval time-delay chaotic systems via the evolutionary programming (EP) approach. First a delay-dependent criterion is derived for ensuring the stability of degenerate time-delay systems, and then by solving eigenvalue location optimization problems, which will be defined later, the robust stability of interval time-delay systems can be guaranteed. An example is given to verify our method that yields less conservative results than those appeared in the literature.

  15. Elastomeric Structural Attachment Concepts for Aircraft Flap Noise Reduction - Challenges and Approaches to Hyperelastic Structural Modeling and Analysis

    Science.gov (United States)

    Sreekantamurthy, Thammaiah; Turner, Travis L.; Moore, James B.; Su, Ji

    2014-01-01

    Airframe noise is a significant part of the overall noise of transport aircraft during the approach and landing phases of flight. Airframe noise reduction is currently emphasized under the Environmentally Responsible Aviation (ERA) and Fixed Wing (FW) Project goals of NASA. A promising concept for trailing-edge-flap noise reduction is a flexible structural element or link that connects the side edges of the deployable flap to the adjacent main-wing structure. The proposed solution is distinguished by minimization of the span-wise extent of the structural link, thereby minimizing the aerodynamic load on the link structure at the expense of increased deformation requirement. Development of such a flexible structural link necessitated application of hyperelastic materials, atypical structural configurations and novel interface hardware. The resulting highly-deformable structural concept was termed the FLEXible Side Edge Link (FLEXSEL) concept. Prediction of atypical elastomeric deformation responses from detailed structural analysis was essential for evaluating feasible concepts that met the design constraints. The focus of this paper is to describe the many challenges encountered with hyperelastic finite element modeling and the nonlinear structural analysis of evolving FLEXSEL concepts. Detailed herein is the nonlinear analysis of FLEXSEL concepts that emerged during the project which include solid-section, foamcore, hollow, extended-span and pre-stressed concepts. Coupon-level analysis performed on elastomeric interface joints, which form a part of the FLEXSEL topology development, are also presented.

  16. Combined supra-transorbital keyhole approach for treatment of delayed intraorbital encephalocele: A minimally invasive approach for an unusual complication of decompressive craniectomy

    Science.gov (United States)

    di Somma, Lucia; Iacoangeli, Maurizio; Nasi, Davide; Balercia, Paolo; Lupi, Ettore; Girotto, Riccardo; Polonara, Gabriele; Scerrati, Massimo

    2016-01-01

    Background: Intraorbital encephalocele is a rare entity characterized by the herniation of cerebral tissue inside the orbital cavity through a defect of the orbital roof. In patients who have experienced head trauma, intraorbital encephalocele is usually secondary to orbital roof fracture. Case Description: We describe here a case of a patient who presented an intraorbital encephalocele 2 years after severe traumatic brain injury, treated by decompressive craniectomy and subsequent autologous cranioplasty, without any evidence of orbital roof fracture. The encephalocele removal and the subsequent orbital roof reconstruction were performed by using a modification of the supraorbital keyhole approach, in which we combine an orbital osteotomy with a supraorbital minicraniotomy to facilitate view and access to both the anterior cranial fossa and orbital compartment and to preserve the already osseointegrated autologous cranioplasty. Conclusions: The peculiarities of this case are the orbital encephalocele without an orbital roof traumatic fracture, and the combined minimally invasive approach used to fix both the encephalocele and the orbital roof defect. Delayed intraorbital encephalocele is probably a complication related to an unintentional opening of the orbit during decompressive craniectomy through which the brain herniated following the restoration of physiological intracranial pressure gradients after the bone flap repositioning. The reconstruction of the orbital roof was performed by using a combined supra-transorbital minimally invasive approach aiming at achieving adequate surgical exposure while preserving the autologous cranioplasty, already osteointegrated. To the best of our knowledge, this approach has not been previously used to address intraorbital encephalocele. PMID:26862452

  17. Modelling biochemical networks with intrinsic time delays: a hybrid semi-parametric approach

    Directory of Open Access Journals (Sweden)

    Oliveira Rui

    2010-09-01

    Full Text Available Abstract Background This paper presents a method for modelling dynamical biochemical networks with intrinsic time delays. Since the fundamental mechanisms leading to such delays are many times unknown, non conventional modelling approaches become necessary. Herein, a hybrid semi-parametric identification methodology is proposed in which discrete time series are incorporated into fundamental material balance models. This integration results in hybrid delay differential equations which can be applied to identify unknown cellular dynamics. Results The proposed hybrid modelling methodology was evaluated using two case studies. The first of these deals with dynamic modelling of transcriptional factor A in mammalian cells. The protein transport from the cytosol to the nucleus introduced a delay that was accounted for by discrete time series formulation. The second case study focused on a simple network with distributed time delays that demonstrated that the discrete time delay formalism has broad applicability to both discrete and distributed delay problems. Conclusions Significantly better prediction qualities of the novel hybrid model were obtained when compared to dynamical structures without time delays, being the more distinctive the more significant the underlying system delay is. The identification of the system delays by studies of different discrete modelling delays was enabled by the proposed structure. Further, it was shown that the hybrid discrete delay methodology is not limited to discrete delay systems. The proposed method is a powerful tool to identify time delays in ill-defined biochemical networks.

  18. Further triple integral approach to mixed-delay-dependent stability of time-delay neutral systems.

    Science.gov (United States)

    Wang, Ting; Li, Tao; Zhang, Guobao; Fei, Shumin

    2017-09-01

    This paper studies the asymptotic stability for a class of neutral systems with mixed time-varying delays. Through utilizing some Wirtinger-based integral inequalities and extending the convex combination technique, the upper bound on derivative of Lyapunov-Krasovskii (L-K) functional can be estimated more tightly and three mixed-delay-dependent criteria are proposed in terms of linear matrix inequalities (LMIs), in which the nonlinearity and parameter uncertainties are also involved, respectively. Different from those existent works, based on the interconnected relationship between neutral delay and state one, some novel triple integral functional terms are constructed and the conservatism can be effectively reduced. Finally, two numerical examples are given to show the benefits of the proposed criteria. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  19. Decision Making in Double-Pedicled DIEP and SIEA Abdominal Free Flap Breast Reconstructions: An Algorithmic Approach and Comprehensive Classification

    OpenAIRE

    Malata, Charles M.; Nicholas Grant Rabey

    2015-01-01

    Introduction The deep inferior epigastric artery perforator free flap is the gold standard for autologous breast reconstruction. However, using a single vascular pedicle may not yield sufficient tissue in patients with midline scars or insufficient lower abdominal pannus. Double-pedicled free flaps overcome this problem using different vascular arrangements to harvest the entire lower abdominal flap. The literature is, however, sparse regarding technique selection. We therefore reviewed ou...

  20. Delay decomposition approach to [Formula: see text] filtering analysis of genetic oscillator networks with time-varying delays.

    Science.gov (United States)

    Revathi, V M; Balasubramaniam, P

    2016-04-01

    In this paper, the [Formula: see text] filtering problem is treated for N coupled genetic oscillator networks with time-varying delays and extrinsic molecular noises. Each individual genetic oscillator is a complex dynamical network that represents the genetic oscillations in terms of complicated biological functions with inner or outer couplings denote the biochemical interactions of mRNAs, proteins and other small molecules. Throughout the paper, first, by constructing appropriate delay decomposition dependent Lyapunov-Krasovskii functional combined with reciprocal convex approach, improved delay-dependent sufficient conditions are obtained to ensure the asymptotic stability of the filtering error system with a prescribed [Formula: see text] performance. Second, based on the above analysis, the existence of the designed [Formula: see text] filters are established in terms of linear matrix inequalities with Kronecker product. Finally, numerical examples including a coupled Goodwin oscillator model are inferred to illustrate the effectiveness and less conservatism of the proposed techniques.

  1. Endoscopic combined “transseptal/transnasal” approach for pituitary adenoma: reconstruction of skull base using pedicled nasoseptal flap in 91 consecutive cases

    Directory of Open Access Journals (Sweden)

    Yasunori Fujimoto

    2015-07-01

    Full Text Available Objective The purpose of this study was to describe the endoscopic combined “transseptal/transnasal” approach with a pedicled nasoseptal flap for pituitary adenoma and skull base reconstruction, especially with respect to cerebrospinal fluid (CSF fistula.Method Ninety-one consecutive patients with pituitary adenomas were retrospectively reviewed. All patients underwent the endoscopic combined “transseptal/transnasal” approach by the single team including the otorhinolaryngologists and neurosurgeons. Postoperative complications related to the flap were analyzed.Results Intra- and postoperative CSF fistulae were observed in 36 (40% and 4 (4.4% patients, respectively. Among the 4 patients, lumbar drainage and bed rest healed the CSF fistula in 3 patients and reoperation for revision was necessary in one patient. Other flap-related complications included nasal bleeding in 3 patients (3.3%.Conclusion The endoscopic combined “transseptal/transnasal” approach is most suitable for a two-surgeon technique and a pedicled nasoseptal flap is a reliable technique for preventing postoperative CSF fistula in pituitary surgery.

  2. An approach to constitutional delay of growth and puberty

    Directory of Open Access Journals (Sweden)

    Ashraf T Soliman

    2012-01-01

    Full Text Available Constitutional delay of growth and puberty is a transient state of hypogonadotropic hypogonadism associated with prolongation of childhood phase of growth, delayed skeletal maturation, delayed and attenuated pubertal growth spurt, and relatively low insulin-like growth factor-1 secretion. In a considerable number of cases, the final adult height (Ht does not reach the mid-parental or the predicted adult Ht for the individual, with some degree of disproportionately short trunk. In the pre-pubertal male, testosterone (T replacement therapy can be used to induce pubertal development, accelerate growth and relieve the psychosocial complaints of the adolescents. However, some issues in the management are still unresolved. These include type, optimal timing, dose and duration of sex steroid treatment and the possible use of adjunctive or alternate therapy including: oxandrolone, aromatase inhibitors and human growth hormone.

  3. Quantum time delay in chaotic scattering: a semiclassical approach

    Energy Technology Data Exchange (ETDEWEB)

    Vallejos, R.O.; Ozorio de Almeida, A.M. [Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil); Lewenkopf, C.H. [Instituto de Fisica, UERJ, Rio de Janeiro (Brazil)

    1998-05-29

    We study the universal fluctuations of the Wigner-Smith time delay for systems which exhibit chaotic dynamics in their classical limit. We present a new derivation of the semiclassical relation of the quantum time delay to properties of the set of trapped periodic orbits in the repeller. As an application, we calculate the energy correlator in the crossover regime between preserved and fully broken time reversal symmetry. We discuss the range of validity of our results and compare them with the predictions of random matrix theories. (author)

  4. Delays caused by incidents. Data-driven approach

    NARCIS (Netherlands)

    Snelder, M.; Bakri, T.; Arem, B. van

    2013-01-01

    Road networks are becoming more vulnerable to incidents as a result of the increasing level of congestion. An innovative empirical method is proposed and applied to analyze the delays caused by about 490,000 incidents that occurred in the Netherlands in the period 2007 to 2009. The method was

  5. Lyapunov Matrices Approach to the Parametric Optimization of a System with Two Delays

    Directory of Open Access Journals (Sweden)

    Duda Jozef

    2016-09-01

    Full Text Available In the paper a Lyapunov matrices approach to the parametric optimization problem of time-delay systems with two commensurate delays and a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of the Lyapunov functional for the initial function of time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix.

  6. Chaos control via TDFC in time-delayed systems: The harmonic balance approach

    Energy Technology Data Exchange (ETDEWEB)

    Vasegh, Nastaran [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)], E-mail: vasegh@eetd.kntu.ac.ir; Khaki Sedigh, Ali [Faculty of Electrical Engineering, K.N. Toosi University of Technology, PO Box 16315-1355, Tehran (Iran, Islamic Republic of)

    2009-01-12

    This Letter deals with the problem of designing time-delayed feedback controllers (TDFCs) to stabilize unstable equilibrium points and periodic orbits for a class of continuous time-delayed chaotic systems. Harmonic balance approach is used to select the appropriate controller parameters: delay time and feedback gain. The established theoretical results are illustrated via a case study of the well-known Logistic model.

  7. Approaches to Delay Claims Assessment Employed in the UK Construction Industry

    Directory of Open Access Journals (Sweden)

    Nuhu Braimah

    2013-09-01

    Full Text Available Construction project delays emanates from multiplicity of different sources of risk events. This, combined with high uncertainty in cause-effect relationships between the events and their impacts on project completion dates, have created immense difficulties in apportioning project delay responsibilities amongst contracting parties. This challenge is now dealt with by various delay analysis approaches, yet delay claims settlement continues to be a troublesome undertaking. Empirical research on these approaches as to their application in practice is limited, although such studies provide important reference sources to practitioners and researchers. As a contribution to addressing this gap, this paper reports on practitioners’ views on the approaches based on a UK nation-wide questionnaire survey of construction and consulting companies. The key findings of the study include: (1 delay claims are often resolved late and not close in time of occurrence of the delay events, creating more difficulties; (2 simplistic delay analysis approaches are widely used in practice and form the basis of successful claim resolutions, although they have major weaknesses; (3 the sophisticated approaches, although are more robust, are generally not popular in practice. To promote the use of these reliable approaches and help reduce or avoid disputes amongst claims parties, programming and record keeping practices must be improved as they do not facilitate the use of the approaches.

  8. Plantar rotational flap technique for panmetatarsal head resection and transmetatarsal amputation: a revision approach for second metatarsal head transfer ulcers in patients with previous partial first ray amputation.

    Science.gov (United States)

    Boffeli, Troy J; Reinking, Ryan

    2014-01-01

    Transfer ulcers beneath the second metatarsal head are common after diabetes-related partial first ray amputation. Subsequent osteomyelitis of the second ray can further complicate this difficult situation. We present 2 cases depicting our plantar rotational flap technique for revision surgery involving conversion to either panmetatarsal head resection or transmetatarsal amputation (TMA). These cases are presented to demonstrate our indications, procedure selection criteria, flap technique, operative pearls, and staging protocol. The goals of this surgical approach are to excise and close the plantar ulcer beneath the second metatarsal head, remove any infected bone, allow staged surgery if needed, remove all remaining metatarsal heads to decrease the likelihood of repeat transfer ulcers, preserve the toes when practical, avoid excessive shortening of the foot, avoid multiple longitudinal dorsal incisions, and create a functional and cosmetically appealing foot. The flap is equally suited for either panmetatarsal head resection or TMA. The decision to pursue panmetatarsal head resection versus TMA largely depends on the condition of the remaining toes. Involvement of osteomyelitis in the base of the second proximal phalanx, the soft tissue viability of the remaining toes, the presence of a preoperative digital deformity, and the likelihood that saving the lesser toes will be beneficial from a cosmetic or footwear standpoint are factors we consider when deciding between panmetatarsal head resection and TMA. Retrospective chart review identified prompt healing of the flap in both patients. Neither patient experienced recurrent ulcers or required subsequent surgery within the first 12 months postoperatively.

  9. Decision making in double-pedicled DIEP and SIEA abdominal free flap breast reconstructions: An algorithmic approach and comprehensive classification.

    Directory of Open Access Journals (Sweden)

    Charles M Malata

    2015-10-01

    Full Text Available Introduction: The deep inferior epigastric artery perforator (DIEP free flap is the gold standard for autologous breast reconstruction. However, using a single vascular pedicle may not yield sufficient tissue in patients with midline scars or insufficient lower abdominal pannus. Double-pedicled free flaps overcome this problem using different vascular arrangements to harvest the entire lower abdominal flap. The literature is, however, sparse regarding technique selection. We therefore reviewed our experience in order to formulate an algorithm and comprehensive classification for this purpose. Methods: All patients undergoing unilateral double-pedicled abdominal perforator free flap breast reconstruction (AFFBR by a single surgeon (CMM over 40 months were reviewed from a prospectively collected database. Results: Of the 112 consecutive breast free flaps performed, 25 (22% utilised two vascular pedicles. The mean patient age was 45 years (range=27-54. All flaps but one (which used the thoracodorsal system were anastomosed to the internal mammary vessels using the rib-preservation technique. The surgical duration was 656 minutes (range=468-690 mins. The median flap weight was 618g (range=432-1275g and the mastectomy weight was 445g (range=220-896g. All flaps were successful and only three patients requested minor liposuction to reduce and reshape their reconstructed breasts.Conclusion: Bipedicled free abdominal perforator flaps, employed in a fifth of all our AFFBRs, are a reliable and safe option for unilateral breast reconstruction. They, however, necessitate clear indications to justify the additional technical complexity and surgical duration. Our algorithm and comprehensive classification facilitate technique selection for the anastomotic permutations and successful execution of these operations.

  10. New approach for virtual surgical planning and mandibular reconstruction using a fibula free flap.

    Science.gov (United States)

    Mottini, Matthias; Seyed Jafari, S M; Shafighi, Maziar; Schaller, Benoît

    2016-08-01

    Maxillofacial reconstruction poses a major challenge to surgeons because of the associated anatomical complexity, the sensitivity of the involved systems and the need to maintain a pleasing facial appearance. Here, we present a detailed description of a new method for extensive mandibular reconstruction using open-source virtual design software and a desktop 3D printer. A surgeon segmented preoperative computed tomography angiography scans with the Amira program to create a digital model of the mandible, skull and fibula. These datasets were imported into Blender, an open-source computer-aided design software package, where arrangement of the fibula segments into aligned sections was performed. Then, a desktop 3D printer was used to produce a reconstructed mandible. After fixation of a plate onto the reconstructed mandible, cutting guides were digitally designed using Blender. Following this, the surgeon performed mandible resection using the fixed cutting guides, which were 3D-printed using biocompatible plastic (Med 610/Stratasys Inc.) and fixed to the prebent reconstructed mandible at a predetermined position. After cutting the fibula with the help of the cutting guides and aligning the fibular segments into mandibular space, the surgeon fixed the segments to the reconstruction plate. Postoperatively, multislice computed tomography scans were taken for control purposes. Our method for mandibular reconstruction offers the following benefits: shorter operation planning time, increased accuracy during osteotomy through the use of a special fibula cutting guide and low costs. In brief, this method is an easy, precise and highly flexible technique for mandibular reconstruction with a fibula flap.

  11. A New Integral Inequality and Delay-Decomposition with Uncertain Parameter Approach to the Stability Analysis of Time-Delay Systems

    Directory of Open Access Journals (Sweden)

    Haiyang Zhang

    2016-01-01

    Full Text Available This paper is concerned with the problem of delay-dependent stability of time-delay systems. Firstly, it introduces a new useful integral inequality which has been proved to be less conservative than the previous inequalities. Next, the inequality combines delay-decomposition approach with uncertain parameters applied to time-delay systems, based on the new Lyapunov-Krasovskii functionals and new stability criteria for system with time-delay have been derived and expressed in terms of LMIs. Finally, a numerical example is provided to show the effectiveness and the less conservative feature of the proposed method compared with some recent results.

  12. Adjoint-based optimization of flapping plates hinged with a trailing-edge flap

    Directory of Open Access Journals (Sweden)

    Min Xu

    2015-01-01

    Full Text Available It is important to understand the impact of wing-morphing on aerodynamic performance in the study of flapping-wing flight of birds and insects. We use a flapping plate hinged with a trailing-edge flap as a simplified model for flexible/morphing wings in hovering. The trailing-edge flapping motion is optimized by an adjoint-based approach. The optimized configuration suggests that the trailing-edge flap can substantially enhance the overall lift. Further analysis indicates that the lift enhancement by the trailing-edge flapping is from the change of circulation in two ways: the local circulation change by the rotational motion of the flap, and the modification of vortex shedding process by the relative location between the trailing-edge flap and leading-edge main plate.

  13. Shoulder adduction contracture after burn: anatomy and treatment with quadrangular local scar subcutaneous pedicled flap, a new approach.

    Science.gov (United States)

    Grishkevich, Viktor M

    2013-11-01

    Axillary adduction contracture is caused by scars that tightly surround the shoulder joint impairing the function of the upper limb. Due to severe scar surface deficiency, contracture release presents a challenge for surgeons since a method of release is transfer of tissue in the form of a large pedicled or free flap(s). Thus, development of simpler, less traumatic techniques, using local tissues, persists. Anatomic studies of shoulder adduction contractures after burn (pre-operative, during surgery, post-reconstruction) were done in 346 pediatric and adult patients. All were divided into three groups according to contracture types: with edge contractures (80%), medial (6%) and total (14%). Anatomical study covered peculiarities of total contractures and possibilities for their treatment using local scarred tissue. Total contractures (48 patients) were caused by scars tightly surrounding the joint on three sides: anterior, posterior, and axillary. There were two specific forms of contracture: (a) shoulder close to the chest wall (22 of 48 patients) which was treated with thoracic pedicled or free flaps; (b) in 26 out of 48 patients a flat scar and skin graft surface laid along the shoulder and chest wall, in axillary projection, which were used for contracture release in the form of a subcutaneous pedicled quadrangular flap. The flap was mobilized only peripherally, descending to the apex of the axilla, forming the central axillary zone, and suspension of the axilla on a normal level. Wounds aside the flaps were covered with skin graft. Acceptable functional and cosmetic results were achieved in all 26 patients. Total shoulder adduction contractures have two forms: (a) shoulder close/fused with the chest wall; and (b) along the chest wall and shoulder there is a flat surface, the tissue of which can be used for reconstruction in a form of scar subcutaneous pedicled quadrangular flap. Based on this flap, a new technique is described which is relatively easy to

  14. Linear matrix inequality approach for synchronization control of fuzzy cellular neural networks with mixed time delays

    Institute of Scientific and Technical Information of China (English)

    P. Balasubramaniam; M. Kalpana; R. Rakkiyappan

    2012-01-01

    Fuzzy cellular neural networks (FCNNs) are special kinds of cellular neural networks (CNNs).Each cell in an FCNN contains fuzzy operating abilities.The entire network is governed by cellular computing laws.The design of FCNNs is based on fuzzy local rules.In this paper,a linear matrix inequality (LMI) approach for synchronization control of FCNNs with mixed delays is investigated.Mixed delays include discrete time-varying delays and unbounded distributed delays.A dynamic control scheme is proposed to achieve the synchronization between a drive network and a response network.By constructing the Lyapunov-Krasovskii functional which contains a triple-integral term and the free-weighting matrices method an improved delay-dependent stability criterion is derived in terms of LMIs.The controller can be easily obtained by solving the derived LMIs.A numerical example and its simulations are presented to illustrate the effectiveness of the proposed method.

  15. Microdialysis in reconstructive surgery : a clinical and experimental study focusing on monitoring flap metabolism and viability

    OpenAIRE

    Röjdmark, Jonas

    2000-01-01

    When flap procedures are used to repair complex tissue wounds adequate flap circulation is of supreme importance. If the circulation is disturbed by either vascular occlusion, hemorrhage, or infection, delayed healing and flap necrosis may ensue. Early recognition of flap ischemia followed by appropriate surgical and/or pharmacotherapeutical measures may be crucial for flap survival. In the present thesis the microdialysis (MD) technique was used for the first time in recons...

  16. Fasciocutaneous flaps

    NARCIS (Netherlands)

    D.E. Tolhurst (David)

    1988-01-01

    textabstractAbout that time the concept of independent myocutaneous vascular territories (Me Craw and Dibbell, 1977) was beginning to take hold but the deep fascia, sandwiched between muscles and the skin, was largely regarded as an isolating layer of dense, avascular fibrous tissue from which flaps

  17. A biologically motivated signal transmission approach based on stochastic delay differential equation.

    Science.gov (United States)

    Xu, Mingdong; Wu, Fan; Leung, Henry

    2009-09-01

    Based on the stochastic delay differential equation (SDDE) modeling of neural networks, we propose an effective signal transmission approach along the neurons in such a network. Utilizing the linear relationship between the delay time and the variance of the SDDE system output, the transmitting side encodes a message as a modulation of the delay time and the receiving end decodes the message by tracking the delay time, which is equivalent to estimating the variance of the received signal. This signal transmission approach turns out to follow the principle of the spread spectrum technique used in wireless and wireline wideband communications but in the analog domain rather than digital. We hope the proposed method might help to explain some activities in biological systems. The idea can further be extended to engineering applications. The error performance of the communication scheme is also evaluated here.

  18. Novel delay-partitioning stabilization approach for networked control system via Wirtinger-based inequalities.

    Science.gov (United States)

    Li, Zhichen; Bai, Yan; Huang, Congzhi; Cai, Yunfei

    2016-03-01

    This paper studies the problems of stability analysis and state feedback stabilization for networked control system. By developing a novel delay-partitioning approach, the information on both the range of network-induced delay and the maximum number of consecutive data packet dropouts can be taken into full consideration. Various augmented Lyapunov-Krasovskii functionals (LKFs) with triple-integral terms are constructed for the two delay subintervals. Moreover, the Wirtinger-based inequalities in combination with an improved reciprocal convexity are utilized to estimate the derivatives of LKFs more accurately. The proposed approaches have improved the stability conditions without increasing much computational complexity. Based on the obtained stability criterion, a stabilization controller design approach is also given. Finally, four numerical examples are presented to illustrate the effectiveness and outperformance of the proposed approaches.

  19. Structural Controllability of Discrete-Time Linear Control Systems with Time-Delay: A Delay Node Inserting Approach

    OpenAIRE

    Ailing Qi; Xuewei Ju; Qing Zhang; Zengqiang Chen

    2016-01-01

    This paper is concerned with the structural controllability analysis for discrete-time linear control systems with time-delay. By adding virtual delay nodes, the linear systems with time-delay are transformed into corresponding linear systems without time-delay, and the structural controllability of them is equivalent. That is to say, the time-delay does not affect or change the controllability of the systems. Several examples are also presented to illustrate the theoretical results.

  20. On the asymptotic stability of linear discrete time-delay systems: The Lyapunov approach

    Directory of Open Access Journals (Sweden)

    Stojanović Sreten B.

    2006-01-01

    Full Text Available New conditions for the stability of discrete delay systems of the form x (k+1 = Arjx (k + Aix (k-h are presented in the paper. These new delay-independent conditions were derived using an approach based on the second Lyapunov's method. These results are less conservative than some in the existing literature. A numerical example was worked out to show the applicability of the derived results.

  1. Lyapunov matrices approach to the parametric optimization of time-delay systems

    Directory of Open Access Journals (Sweden)

    Duda Józef

    2015-09-01

    Full Text Available In the paper a Lyapunov matrices approach to the parametric optimization problem of time-delay systems with a P-controller is presented. The value of integral quadratic performance index of quality is equal to the value of Lyapunov functional for the initial function of the time-delay system. The Lyapunov functional is determined by means of the Lyapunov matrix

  2. Robust H∞ Control for Singular Time-Delay Systems via Parameterized Lyapunov Functional Approach

    Directory of Open Access Journals (Sweden)

    Li-li Liu

    2014-01-01

    Full Text Available A new version of delay-dependent bounded real lemma for singular systems with state delay is established by parameterized Lyapunov-Krasovskii functional approach. In order to avoid generating nonconvex problem formulations in control design, a strategy that introduces slack matrices and decouples the system matrices from the Lyapunov-Krasovskii parameter matrices is used. Examples are provided to demonstrate that the results in this paper are less conservative than the existing corresponding ones in the literature.

  3. Lateral thoracic artery perforator (LTAP) flap in partial breast reconstruction.

    Science.gov (United States)

    McCulley, Stephen J; Schaverien, Mark V; Tan, Veronique K M; Macmillan, R Douglas

    2015-05-01

    Partial breast reconstruction using pedicled perforator flaps from the thoracodorsal (TDAP) and lateral intercostal arteries (LICAP) is well described. The article introduces the lateral thoracic artery perforator (LTAP) flap as an additional valuable option from the lateral chest wall and reports clinical experience and outcomes. The anatomy of the LTAP flap is reviewed and the results of a consecutive series are reported. In a series of 75 consecutive cases of lateral chest wall perforator flaps used for reconstruction of partial breast defects, 12 (17%) were raised as pure LTAP flaps, and a further 19 (27%) as combined LTAP/LICAP flaps. The LTAP was therefore used in 44% of flaps overall. One LTAP flap (delayed case) had early venous compromise that settled spontaneously. The LTAP flap is a reliable option for partial breast reconstruction from the lateral chest wall, particularly in the immediate setting. It allows comparable flap size to be harvested compared to LICAP flaps. The LTAP flap can be raised on its own pedicle allowing greater mobilization or it can be incorporated into the more commonly used LICAP flap to augment perfusion. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. Bilateral telemanipulation With time delays: a two-layer approach combining passivity and transparency

    NARCIS (Netherlands)

    Franken, Michel; Stramigioli, Stefano; Misra, Sarthak; Secchi, Cristian; Macchelli, Alessandro

    2011-01-01

    In this paper, a two-layer approach is presented to guarantee the stable behavior of bilateral telemanipulation sys- tems in the presence of time-varying destabilizing factors such as hard contacts, relaxed user grasps, stiff control settings, and/or communication delays. The approach splits the con

  5. Microsurgical free flap reconstructions of the head and neck region: Shanghai experience of 34 years and 4640 flaps.

    Science.gov (United States)

    Zhang, C; Sun, J; Zhu, H; Xu, L; Ji, T; He, Y; Yang, W; Hu, Y; Yang, X; Zhang, Z

    2015-06-01

    This study represents the surgical experience of 4481 microvascular free flap cases performed at the authors' institution in China, between 1979 and 2013. Four thousand four hundred and eighty-one patients underwent reconstruction with 4640 flaps: 56% radial forearm flaps, 8% iliac crest flaps, 13% fibula flaps, 10% anterolateral thigh flaps, and other flaps. In the overwhelming majority of cases, the flap transfer was required following tumour resection (97.5%). Three hundred and twenty minor complications (6.9%) occurred. One hundred and eighteen major complications (2.5%) were encountered: 114 cases of failure (2.4%) and four deaths. Among the 118 cases with major complications, 26 - 22.0% - had received radiotherapy; this proportion was higher than the 6.9% in the minor complications group and 8.1% in the non-intervention group. Venous thrombosis was the most common complication at the recipient site and was the main cause of flap failure. When a compromised flap is identified, surgical re-exploration should not be delayed. This study confirms that free flaps are reliable in achieving successful reconstruction in the head and neck region; however this technique requires extensive clinical experience. Owing to the large number of flap options, microsurgeons should always pay attention to the details of the different surgical defects and choose the most appropriate flap.

  6. A Controllability Approach for Resonant Compliant Systems: Applied to a Flapping Wing Micro Air Vehicle

    NARCIS (Netherlands)

    Peters, H.J.

    2016-01-01

    This thesis studies a controllability approach for general resonant compliant systems. These systems exploit resonance to obtain a specific dynamic response at relatively low actuation power. This type of systems is often lightweight, is scalable and minimizes frictional losses through the use of co

  7. Extended anterolateral thigh pedicled flap for reconstruction of trochanteric and gluteal defects: A new & innovative approach for reconstruction

    Institute of Scientific and Technical Information of China (English)

    G.I.Nambi; Abhijeet Ashok Salunke; Szeryn Chung; K.S.Raj Kumar; Vikram Anil Chaudhari; Anant Dattaray Dhanwate

    2016-01-01

    Descending branch of the lateral circumflex femoral artery (LCFA) is commonly used pedicle for anterolateral thigh (ALT) flap.Oblique branch of LCFA is an alternative pedicle that can be used in microvascular surgery.According to review of literature and to the best of our knowledge we could not find the use of oblique branch of LCFA as a pedicle of the ALT flap in regional soft tissue reconstruction.Here we presented a case of a 55-year-old man sustaining soft tissue injury and wound over the left trochanteric and gluteal region following a road traffic accident,who was treated by the use of extended ALT pedicle flap with oblique branch of LCFA as the pedicle for reconstruction of soft tissue defect in trochanteric and gluteal regions with successful outcome.

  8. Anatomic basis for an algorithmic approach for free fibula flap donor side selection in composite oro-mandibular defects

    Directory of Open Access Journals (Sweden)

    Mohit Sharma

    2015-01-01

    Full Text Available Introduction: Head and neck oncological resections may result in composite oro-mandibular defects involving the oral mucosa (lining, mandibular bone and the skin (cover. Reconstructive options for such defects have evolved over a period. Free fibula flap reconstruction is currently accepted the world over as the gold standard for oro-mandibular defect reconstruction. Existing literature provides conflicting views about the use of a particular side and orientation of the fibula flap for achieving the optimal outcome. The purpose of this study is to confirm anatomically the effect of bone, soft tissue and vessel orientation on the ease of doing reconstruction. Materials and Methods: This is a cadaveric study. A mandibular model with a defect was used. This was pre plated to maintain continuity. Composite fibula flaps of the same dimension were harvested from both legs of a fresh cadaver. The harvested flaps were used to reconstruct the mandibular defect in different orientations and the best configuration for each reconstructive requirement was assessed. Results: Keeping the peroneal surface for plating, that is, facing outwards, four different configurations of the fibula flap are possible for a given mandibular defect. With a posterior vascular pedicle ipsilateral fibula is suitable for skin cover and contralateral for mucosal lining and the reverse for an anteriorly placed pedicle. Conclusion: The algorithm based selection of appropriate sided fibula flap facilitates complex mandibular reconstruction by placing the right kind of tissue at the right place and helps in reducing the donor site morbidity by allowing the surgeon to harvest only the required amount of skin.

  9. Further results on stabilization for interval time-delay systems via new integral inequality approach.

    Science.gov (United States)

    Li, Zhichen; Bai, Yan; Huang, Congzhi; Yan, Huaicheng

    2017-05-01

    This paper investigates the stability and stabilization problems for interval time-delay systems. By introducing a new delay partitioning approach, various Lyapunov-Krasovskii functionals with triple-integral terms are established to make full use of system information. In order to reduce the conservatism, improved integral inequalities are developed for estimation of double integrals, which show remarkable outperformance over the Jensen and Wirtinger ones. Particularly, the relationship between the time-delay and each subinterval is taken into consideration. The resulting stability criteria are less conservative than some recent methods. Based on the derived condition, the state-feedback controller design approach is also given. Finally, the numerical examples and the application to inverted pendulum system are provided to illustrate the effectiveness of the proposed approaches. Copyright © 2017 ISA. Published by Elsevier Ltd. All rights reserved.

  10. Projective Synchronization in Modulated Time-Delayed Chaotic Systems Using an Active Control Approach

    Institute of Scientific and Technical Information of China (English)

    冯存芳; 汪映海

    2011-01-01

    Projective synchronization in modulated time-delayed systems is studied by applying an active control method. Based on the Lyapunov asymptotical stability theorem, the controller and sufficient condition for projective synchronization are calculated analytically. We give a genera./ method with which we can achieve projective synchronization in modulated time-delayed chaotic systems. This method allows us to adjust the desired scaling factor arbitrarily. The effectiveness of our method is confirmed by using the famous delay-differential equations related to optical bistable or hybrid optical bistable devices. Numerical simulations fully support the analytical approach.%Projective synchronization in modulated time-delayed systems is studied by applying an active control method.Based on the Lyapunov asymptotical stability theorem,the controller and sufficient condition for projective synchronization are calculated analytically.We give a general method with which we can achieve projective synchronization in modulated time-delayed chaotic systems.This method allows us to adjust the desired scaling factor arbitrarily.The effectiveness of our method is confirmed by using the famous delay-differential equations related to optical bistable or hybrid optical bistable devices.Numerical simulations fully support the analytical approach.

  11. Delayed Monocular SLAM Approach Applied to Unmanned Aerial Vehicles.

    Science.gov (United States)

    Munguia, Rodrigo; Urzua, Sarquis; Grau, Antoni

    2016-01-01

    In recent years, many researchers have addressed the issue of making Unmanned Aerial Vehicles (UAVs) more and more autonomous. In this context, the state estimation of the vehicle position is a fundamental necessity for any application involving autonomy. However, the problem of position estimation could not be solved in some scenarios, even when a GPS signal is available, for instance, an application requiring performing precision manoeuvres in a complex environment. Therefore, some additional sensory information should be integrated into the system in order to improve accuracy and robustness. In this work, a novel vision-based simultaneous localization and mapping (SLAM) method with application to unmanned aerial vehicles is proposed. One of the contributions of this work is to design and develop a novel technique for estimating features depth which is based on a stochastic technique of triangulation. In the proposed method the camera is mounted over a servo-controlled gimbal that counteracts the changes in attitude of the quadcopter. Due to the above assumption, the overall problem is simplified and it is focused on the position estimation of the aerial vehicle. Also, the tracking process of visual features is made easier due to the stabilized video. Another contribution of this work is to demonstrate that the integration of very noisy GPS measurements into the system for an initial short period of time is enough to initialize the metric scale. The performance of this proposed method is validated by means of experiments with real data carried out in unstructured outdoor environments. A comparative study shows that, when compared with related methods, the proposed approach performs better in terms of accuracy and computational time.

  12. Prospective evaluation of outcome measures in free-flap surgery.

    LENUS (Irish Health Repository)

    Kelly, John L

    2004-08-01

    Free-flap failure is usually caused by venous or arterial thrombosis. In many cases, lack of experience and surgical delay also contribute to flap loss. The authors prospectively analyzed the outcome of 57 free flaps over a 28-month period (January, 1999 to April, 2001). The setting was a university hospital tertiary referral center. Anastomotic technique, ischemia time, choice of anticoagulant, and the grade of surgeon were recorded. The type of flap, medications, and co-morbidities, including preoperative radiotherapy, were also documented. Ten flaps were re-explored (17 percent). There were four cases of complete flap failure (6.7 percent) and five cases of partial failure (8.5 percent). In patients who received perioperative systemic heparin or dextran, there was no evidence of flap failure (p = .08). The mean ischemia time was similar in flaps that failed (95 +\\/- 29 min) and in those that survived (92 +\\/- 34 min). Also, the number of anastomoses performed by trainees in flaps that failed (22 percent), was similar to the number in flaps that survived (28 percent). Nine patients received preoperative radiotherapy, and there was complete flap survival in each case. This study reveals that closely supervised anastomoses performed by trainees may have a similar outcome to those performed by more senior surgeons. There was no adverse effect from radiotherapy or increased ischemia time on flap survival.

  13. Haemodynamics and viability of skin and muscle flaps

    Energy Technology Data Exchange (ETDEWEB)

    Clarke, H.M.

    1985-01-01

    In reconstructive surgery, occasional free flap failures occur despite the clinical and technical advances in microsurgery of the past few years. To minimize these losses a better understanding of basic flap physiology must be achieved. The objectives of this work were the investigation of the haemodynamic characteristics of skin and muscle flaps in normal and compromised circumstances, the viability of skin and muscle flaps after pedicle ligation or ischaemia, and the possible interrelationship of haemodynamics and viability. A Wistar rat groin island skin flap model was used to assess flap survival following vascular compromise produced by vessel ligation. Survival was seen earliest following loss of the artery and was not dependent on circulation through the vascular pedicle after 5 days. A study using free groin flaps in rats gave similar results. Normal free groin flaps were then transferred to irradiated Fischer F344 rats. Delayed neovascularization was shown at a time corresponding to the onset of the late phase of the response to skin radiation. A canine inferior epigastric free skin flap model was established to determine the normal haemodynamic parameters during free flap transfer. A canine gracilis free muscle flap model was developed. Normal haemodynamic parameters are given. These parameters were examined after ischaemia. Survival of the muscle followed ischaemia of 4 hours or less. Flap survival is not dependent solely on arterial input or venous drainage. More complex phenomena such as the reactive hyperaemia following ischaemia are implicated in survival.

  14. The interpectoral fascia flap.

    Science.gov (United States)

    Beer, Gertrude M; Manestar, Andrew; Manestar, Mirjana

    2008-09-01

    Despite the great number of pedicled and free flaps that are available for defect and contour repair, the number of fascia flaps with an axial blood supply are sparse. Such flaps with their gliding function are mandatory, whenever coverage with very thin, well-vascularized tissue is necessary. To the currently established fascia flaps, (the temporoparietal fascia flap, the radial forearm fascia flap, the lateral arm fascia flap, and the serratus anterior fascia flap), we want to add a new fascia flap, the interpectoral fascia flap. We dissected the interpectoral fascia flap from 20 cadavers. In each of the 40 hemichests, the trunk of the thoracoacromial vessels was selectively injected with red polyurethane and the tissue containing the pectoral branches was separated from the overlying pectoralis major muscle and converted into an independent fascia flap. The maximum flap length was 13.5 cm and the maximum breadth was 10.3 cm. The length of the vascular pedicle before entering the flap was 3.9 cm +/- 1.4 cm with a range of 1.5-6.8 cm. Concerning the arc of rotation, all 40 flaps reached the posterior axillary fold, and 29 flaps (73%) reached the mandibular border. This new fascia flap has applications as pedicled and as free flap. The pedicled flap is used in the neck region, in the axillary region and as gliding tissue between the nipple-areola complex and the pectoralis major muscle. The usage of the fascia flap as a free flap has similar characteristics as the other fascia flaps.

  15. A fixed point approach towards stability of delay differential equations with applications to neural networks

    NARCIS (Netherlands)

    Chen, Guiling

    2013-01-01

    This thesis studies asymptotic behavior and stability of determinsitic and stochastic delay differential equations. The approach used in this thesis is based on fixed point theory, which does not resort to any Liapunov function or Liapunov functional. The main contribution of this thesis is to study

  16. Delay-dependent asymptotic stability of mobile ad-hoc networks: A descriptor system approach

    Science.gov (United States)

    Yang, Juan; Yang, Dan; Huang, Bin; Zhang, Xiao-Hong; Luo, Jian-Lu

    2014-07-01

    In order to analyze the capacity stability of the time-varying-propagation and delay-dependent of mobile ad-hoc networks (MANETs), in this paper, a novel approach is proposed to explore the capacity asymptotic stability for the delay-dependent of MANETs based on non-cooperative game theory, where the delay-dependent conditions are explicitly taken into consideration. This approach is based on the Lyapunov—Krasovskii stability theory for functional differential equations and the linear matrix inequality (LMI) technique. A corresponding Lyapunov—Krasovskii functional is introduced for the stability analysis of this system with use of the descriptor and “neutral-type” model transformation without producing any additional dynamics. The delay-dependent stability criteria are derived for this system. Conditions are given in terms of linear matrix inequalities, and for the first time referred to neutral systems with the time-varying propagation and delay-dependent stability for capacity analysis of MANETs. The proposed criteria are less conservative since they are based on an equivalent model transformation. Furthermore, we also provide an effective and efficient iterative algorithm to solve the constrained stability control model. Simulation experiments have verified the effectiveness and efficiency of our algorithm.

  17. Robust H∞ Control of Uncertain T-S Fuzzy Time-Delay System: A Delay Decomposition Approach

    OpenAIRE

    Cheng Gong; Chunsong Han

    2013-01-01

    This paper is concerned with the problem of robust H∞ control for a class of uncertain time-delay fuzzy systems with norm-bounded parameter uncertainties. By utilizing the instrumental idea of delay decomposition, the decomposed Lyapunov-Krasovskii functional is introduced to uncertain T-S fuzzy system, and some delay-dependent conditions for the existence of robust controller are formulated in the form of linear matrix inequalities (LMIs). When these LMIs are feasible, a controller is presen...

  18. H∞ approach to monotonically convergent ILC for uncertain time-varying delay systems

    Science.gov (United States)

    Meng, Deyuan; Jia, Yingmin; Du, Junping

    2015-01-01

    This paper deals with iterative learning control (ILC) design for uncertain time-delay systems. Monotonic convergence of the resulting ILC process is studied, and a sufficient condition within an H∞-based framework is developed. It is shown that under this framework, delay-dependent conditions can be obtained in terms of linear matrix inequalities (LMIs), together with formulas for gain matrices design. A numerical example is provided to illustrate the effectiveness of the robust H∞-based approach to ILC designed via LMIs.

  19. Combining time delays and image positions for quadruple lenses: a moment approach

    CERN Document Server

    Witt, Hans

    2015-01-01

    Time delays in gravitational lenses can be used to determine the Hubble constant and the lens potential. In future surveys, many gravitational lenses can be discovered, and their time delays and image positions can in principle be measured. Using an elliptical power-law potential, we show that combinations of image positions and time delays for quadruple lenses yield simple analytical expressions that are connected with observable quantities. These relations can be used to obtain the approximate axis ratio q, the Einstein radius and the slope. We apply this method to RX J1131-1231, and show that our analytical results match the full numerical determinations approximately. Our approach can quickly determine rough values of lens parameters, which can then be used as initial guesses for further refinement through numerical modelling and may be useful for automated lens search in large surveys.

  20. An LMI approach to robust H-infinity control for uncertain singular time-delay systems

    Institute of Scientific and Technical Information of China (English)

    Xiaofu JI; Hongye SU; Jian CHU

    2006-01-01

    The problem of robust H-infinity control for a class of uncertain singular time-delay systems is studied in this paper. A new approach is proposed to describe the relationship between slow and fast subsystems of singular time-delay systems, based on which, a sufficient condition is presented for a singular time-delay system to be regular, impulse free and stable with an H-infinity performance. The robust H-infinity control problem is solved and an explicit expression of the desired state-feedback control law is also given. The obtained results are formulated in terms of strict linear matrix inequalities (LMIs) involving no decomposition of system matrices. A numerical example is given to show the effectiveness of the proposed method,

  1. Comparison of outcome of microvascular bony head and neck reconstructions using the fibular free flap and the iliac crest flap.

    Science.gov (United States)

    Mücke, Thomas; Loeffelbein, Denys J; Kolk, Andreas; Wagenpfeil, Stefan; Kanatas, Anastasios; Wolff, Klaus-Dietrich; Mitchell, David A; Kesting, Marco R

    2013-09-01

    Several microvascular free flaps are available for reconstruction of the osseous components after resections for head and neck cancer. We have prospectively evaluated patients treated by bony microsurgical reconstruction to identify predictors of adverse outcomes for delayed wound healing and failure of free flaps. All patients from July 2007 to June 2011 who had reconstructions with microvascular fibular or iliac crest flaps immediately after resection of the tumour were evaluated. There were a total of 156 bony free flaps: 120 (77%) fibular and 36 (23%) iliac crest flaps. A total of 133 (85%) were successful. Delayed wound healing was more common with the iliac crest flap (p=0.01) at the intraoral site (p=0.04). Significantly more iliac crest free flaps failed (p=0.02). Anastomosis to the facial artery (p=0.05) and facial vein (p=0.04), and duration of overall operating time were associated with a significantly higher risk of failure of the flap. Patients with cancer of the head and neck who require microsurgical bony reconstruction are at increased risk of postoperative complications. Significantly more complications were found with the iliac crest flap, whereas the fibular flap was associated with a significantly longer operating time.

  2. Three cross leg flaps for lower leg reconstruction of Gustilo type III C open fracture

    Directory of Open Access Journals (Sweden)

    Kazufumi Sano

    2016-01-01

    Full Text Available A 60 year old male had Gustilo type III C open fracture of the right lower leg. After radical debridement, the large open defect including certain loss of the bone tissue was successfully augmented and covered, by consecutive three cross-leg flaps, which consisted of the free rectus abdominis musculocutaneous flap, the fibula osteocutaneous flap and the conventional sural flap. Although indication for amputation or preservation is decided with multiple factors in each case, a strategic combination of cross-leg flap, free flap, external fixation and vascular delay could increase the potential of preservation of the lower leg with even disastrous Gustilo type III C.

  3. A Novel Approach to Sliding Mode Control of Time-Delay Systems

    Directory of Open Access Journals (Sweden)

    Hongwei Xia

    2013-01-01

    Full Text Available This paper is concerned with the sliding mode control for a class of linear systems with time-varying delays. By utilizing a novel Lyapunov-Krasovskii functional and combining it with the delay fractioning approach as well as the free-weighting matrix technology, a sufficient condition is established such that the resulting sliding mode dynamics is asymptotically stable. Then, a sliding mode controller for reaching motion is synthesized to guarantee that the trajectories of the resulting closed-loop system can be driven onto a prescribed sliding surface and maintained there for all subsequent time. A numerical example is provided to illustrate the effectiveness of the proposed design approach.

  4. Series-based approximate approach of optimal tracking control for nonlinear systems with time-delay

    Institute of Scientific and Technical Information of China (English)

    Gongyou Tang; Mingqu Fan

    2008-01-01

    The optimal output tracking control (OTC) problem for nonlinear systems with time-delay is considered.Using a series-based approx-imate approach,the original OTC problem is transformed into iteration solving linear two-point boundary value problems without time-delay.The OTC law obtained consists of analytical linear feedback and feedforward terms and a nonlinear compensation term with an infinite series of the adjoint vectors.By truncating a finite sum of the adjoint vector series,an approximate optimal tracking control law is obtained.A reduced-order reference input observer is constructed to make the feedforward term physically realizable.Simulation exam-pies are used to test the validity of the series-based approximate approach.

  5. Rotational flaps in oncologic breast surgery. Anatomical and technical considerations.

    Science.gov (United States)

    Acea Nebril, Benigno; Builes Ramírez, Sergio; García Novoa, Alejandra; Varela Lamas, Cristina

    2016-01-01

    Local flaps are a group of surgical procedures that can solve the thoracic closure of large defects after breast cancer surgery with low morbidity. Its use in skin necrosis complications after conservative surgery or skin sparing mastectomies facilitates the initiation of adjuvant treatments and reduces delays in this patient group. This article describes the anatomical basis for the planning of thoracic and abdominal local flaps. Also, the application of these local flaps for closing large defects in the chest and selective flaps for skin coverage by necrosis in breast conserving surgery.

  6. Pre-expanded Deep Inferior Epigastric Perforator Flap.

    Science.gov (United States)

    Monsivais, Sharon E; Webster, Nicholas D; Wong, Stacy; Saint-Cyr, Michel H

    2017-01-01

    The deep inferior epigastric perforator (DIEP) flap can be used to cover large defects of the proximal lower extremity, abdominal wall, perineum, vulva, and buttock. Pre-expanding DIEP flaps cause a possible delay phenomenon improving vascularity, decrease donor site morbidity, and increase the area that can be covered. Pre-expansion requires staged procedures, has risk of extrusion and infection, causes temporary contour deformity during the expansion process, and requires a longer course. Pre-expanded DIEP flaps can be a useful flap with proper patient selection and planning. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Robust Stability of Fractional Order Time-Delay Control Systems: A Graphical Approach

    OpenAIRE

    Radek Matušů; Roman Prokop

    2015-01-01

    The paper deals with a graphical approach to investigation of robust stability for a feedback control loop with an uncertain fractional order time-delay plant and integer order or fractional order controller. Robust stability analysis is based on plotting the value sets for a suitable range of frequencies and subsequent verification of the zero exclusion condition fulfillment. The computational examples present the typical shapes of the value sets of a family of closed-loop characteristic qua...

  8. Stabilization of a Wireless Networked Control System with Packet Loss and Time Delay: An ADS Approach

    Directory of Open Access Journals (Sweden)

    Jing Wang

    2012-01-01

    Full Text Available The stabilization problem of a wireless networked control system is considered in this paper. Both time delay and packet loss exist simultaneously in the wireless network. The system is modeled as an asynchronous dynamic system (ADS with unstable subsystems. A sufficient condition for the system to be stable is presented. A numerical example is given to demonstrate the effectiveness of the proposed approach.

  9. Linear matrix inequality approach for robust stability analysis for stochastic neural networks with time-varying delay

    Institute of Scientific and Technical Information of China (English)

    S. Lakshmanan; P. Balasubramaniarn

    2011-01-01

    This paper studies the problem of linear matrix inequality(LMI)approach to robust stability analysis for stochastic neural networks with a time-varying delay. By developing a delay decomposition approach, the information of the delayed plant states can be taken into full consideration. Based on the new Lyapunov-Krasovskii functional, some inequality techniques and stochastic stability theory, new delay-dependent stability criteria are obtained in terms of LMIs. The proposed results prove the less conservatism, which are realized by choosing new Lyapunov matrices in the decomposed integral intervals. Finally, numerical examples are provided to demonstrate the less conservatism and effectiveness of the proposed LMI method.

  10. Estimation-theoretic approach to delayed decoding of predictively encoded video sequences.

    Science.gov (United States)

    Han, Jingning; Melkote, Vinay; Rose, Kenneth

    2013-03-01

    Current video coders employ predictive coding with motion compensation to exploit temporal redundancies in the signal. In particular, blocks along a motion trajectory are modeled as an auto-regressive (AR) process, and it is generally assumed that the prediction errors are temporally independent and approximate the innovations of this process. Thus, zero-delay encoding and decoding is considered efficient. This paper is premised on the largely ignored fact that these prediction errors are, in fact, temporally dependent due to quantization effects in the prediction loop. It presents an estimation-theoretic delayed decoding scheme, which exploits information from future frames to improve the reconstruction quality of the current frame. In contrast to the standard decoder that reproduces every block instantaneously once the corresponding quantization indices of residues are available, the proposed delayed decoder efficiently combines all accessible (including any future) information in an appropriately derived probability density function, to obtain the optimal delayed reconstruction per transform coefficient. Experiments demonstrate significant gains over the standard decoder. Requisite information about the source AR model is estimated in a spatio-temporally adaptive manner from a bit-stream conforming to the H.264/AVC standard, i.e., no side information needs to be sent to the decoder in order to employ the proposed approach, thereby compatibility with the standard syntax and existing encoders is retained.

  11. Delay Mitigation in the Malaysian Housing Industry: A Structural Equation Modelling Approach

    Directory of Open Access Journals (Sweden)

    Chang Saar Chai

    2015-01-01

    Full Text Available The housing industry is one of the major contributors to the economy in Malaysia due to the constantly high housing demand. The housing demand has increased due to the rapid growth in population and urbanisation in the country. One of the major challenges in the housing industry is the late delivery of housing supply, which in some instances leads to sick and abandoned housing projects. Despite being extensively investigated, th in a negative impact, there is a strong need to review the housing delay mitigation measures practised in Malaysia. This paper aims to evaluate the current delay mitigation measures and its main objective is to explore the relationship between the mitigation measures and delay in housing via a Structural Equation Modelling (SEM approach. A questionnaire survey through an online survey tool was conducted across 13 states and three Federal Territories in Malaysia. The target respondents are the local authorities, developers, consultants (principal submitting persons and contractors. The findings show that 17 predictive, preventive, organisational or corrective. This paper demonstrates that preventive measures are the most influential mitigation measures for housing delivery delay.

  12. A Robust and Multi-Weighted Approach to Estimating Topographically Correlated Tropospheric Delays in Radar Interferograms

    Directory of Open Access Journals (Sweden)

    Bangyan Zhu

    2016-07-01

    Full Text Available Spatial and temporal variations in the vertical stratification of the troposphere introduce significant propagation delays in interferometric synthetic aperture radar (InSAR observations. Observations of small amplitude surface deformations and regional subsidence rates are plagued by tropospheric delays, and strongly correlated with topographic height variations. Phase-based tropospheric correction techniques assuming a linear relationship between interferometric phase and topography have been exploited and developed, with mixed success. Producing robust estimates of tropospheric phase delay however plays a critical role in increasing the accuracy of InSAR measurements. Meanwhile, few phase-based correction methods account for the spatially variable tropospheric delay over lager study regions. Here, we present a robust and multi-weighted approach to estimate the correlation between phase and topography that is relatively insensitive to confounding processes such as regional subsidence over larger regions as well as under varying tropospheric conditions. An expanded form of robust least squares is introduced to estimate the spatially variable correlation between phase and topography by splitting the interferograms into multiple blocks. Within each block, correlation is robustly estimated from the band-filtered phase and topography. Phase-elevation ratios are multiply- weighted and extrapolated to each persistent scatter (PS pixel. We applied the proposed method to Envisat ASAR images over the Southern California area, USA, and found that our method mitigated the atmospheric noise better than the conventional phase-based method. The corrected ground surface deformation agreed better with those measured from GPS.

  13. Multivariate time delay analysis based local KPCA fault prognosis approach for nonlinear processes☆

    Institute of Scientific and Technical Information of China (English)

    Yuan Xu; Ying Liu; Qunxiong Zhu

    2016-01-01

    Currently, some fault prognosis technology occasionally has relatively unsatisfied performance especially for in-cipient faults in nonlinear processes duo to their large time delay and complex internal connection. To overcome this deficiency, multivariate time delay analysis is incorporated into the high sensitive local kernel principal com-ponent analysis. In this approach, mutual information estimation and Bayesian information criterion (BIC) are separately used to acquire the correlation degree and time delay of the process variables. Moreover, in order to achieve prediction, time series prediction by back propagation (BP) network is applied whose input is multivar-iate correlated time series other than the original time series. Then the multivariate time delayed series and future values obtained by time series prediction are combined to construct the input of local kernel principal component analysis (LKPCA) model for incipient fault prognosis. The new method has been exemplified in a sim-ple nonlinear process and the complicated Tennessee Eastman (TE) benchmark process. The results indicate that the new method has superiority in the fault prognosis sensitivity over other traditional fault prognosis methods. © 2016 The Chemical Industry and Engineering Society of China, and Chemical Industry Press. Al rights reserved.

  14. An approach to normal forms of Kuramoto model with distributed delays and the effect of minimal delay

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Ben, E-mail: niubenhit@163.com [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Guo, Yuxiao [Department of Mathematics, Harbin Institute of Technology, Weihai 264209 (China); Jiang, Weihua [Department of Mathematics, Harbin Institute of Technology, Harbin 150001 (China)

    2015-09-25

    Heterogeneous delays with positive lower bound (gap) are taken into consideration in Kuramoto model. On the Ott–Antonsen's manifold, the dynamical transitional behavior from incoherence to coherence is mediated by Hopf bifurcation. We establish a perturbation technique on complex domain, by which universal normal forms, stability and criticality of the Hopf bifurcation are obtained. Theoretically, a hysteresis loop is found near the subcritically bifurcated coherent state. With respect to Gamma distributed delay with fixed mean and variance, we find that the large gap decreases Hopf bifurcation value, induces supercritical bifurcations, avoids the hysteresis loop and significantly increases in the number of coexisting coherent states. The effect of gap is finally interpreted from the viewpoint of excess kurtosis of Gamma distribution. - Highlights: • Heterogeneously delay-coupled Kuramoto model with minimal delay is considered. • Perturbation technique on complex domain is established for bifurcation analysis. • Hysteresis phenomenon is investigated in a theoretical way. • The effect of excess kurtosis of distributed delays is discussed.

  15. On Reducing Delay in Mesh-Based P2P Streaming: A Mesh-Push Approach

    Science.gov (United States)

    Liu, Zheng; Xue, Kaiping; Hong, Peilin

    The peer-assisted streaming paradigm has been widely employed to distribute live video data on the internet recently. In general, the mesh-based pull approach is more robust and efficient than the tree-based push approach. However, pull protocol brings about longer streaming delay, which is caused by the handshaking process of advertising buffer map message, sending request message and scheduling of the data block. In this paper, we propose a new approach, mesh-push, to address this issue. Different from the traditional pull approach, mesh-push implements block scheduling algorithm at sender side, where the block transmission is initiated by the sender rather than by the receiver. We first formulate the optimal upload bandwidth utilization problem, then present the mesh-push approach, in which a token protocol is designed to avoid block redundancy; a min-cost flow model is employed to derive the optimal scheduling for the push peer; and a push peer selection algorithm is introduced to reduce control overhead. Finally, we evaluate mesh-push through simulation, the results of which show mesh-push outperforms the pull scheduling in streaming delay, and achieves comparable delivery ratio at the same time.

  16. [Pedicled versus free TRAM flap for breast reconstruction].

    Science.gov (United States)

    Galla, T J; Lukas, B; Feller, A M

    1999-03-01

    In breast reconstruction, the free TRAM-flap offers many advantages over the pedicled TRAM-flap. Due to its superior perfusion, the free flap rarely develops necrosis. Shaping of the flap is easier due to the lack of the thick muscle pedicle. Because the rectus muscle is spared, there is minimal donor site morbidity. However, the necessary microvascular anastomoses reduced the acceptance of the free TRAM-flap. During a 13-months period, 51 breast reconstructions were performed in 41 patients, 31 unilateral and ten bilateral. 45 flaps served for delayed reconstruction and six flaps for immediate reconstruction. The operations were performed by two teams working simultaneously. The average operating time was 3.9 hours for unilateral and 6.9 hours for bilateral delayed reconstruction. For immediate reconstruction, 6.2 and 6.3 hours were required for uni- and bilateral procedures, respectively. In 38 flaps, the thoracodorsal vessels served as recipient vessels; 13 flaps were anastomosed to the internal mammary artery and vein. Postoperative complications were observed in 13 patients. Three vessel anastomoses had to be revised. In one flap, a partial necrosis occurred; in two flaps hematoma evacuation was necessary. Two patients suffered from fat necroses at the abdomen and one umbilicus was lost. Skin irritations and seromas at the abdomen occurred in five patients. Pulmonary embolism was diagnosed in one patient three weeks postoperatively. Abdominal hernias or bulging in the epigastric area were not observed up to 15 months after reconstruction. These results reveal a low complication rate for breast reconstruction with the free TRAM-flap. The advantages of this technique as compared to the pedicled technique are discussed.

  17. ALGORITHM OF MULTIHARMONIC DISTURBANCE COMPENSATION IN LINEAR SYSTEMS WITH ARBITRARY DELAY: INTERNAL MODEL APPROACH

    Directory of Open Access Journals (Sweden)

    Dmitry N. Gerasimov

    2016-11-01

    Full Text Available Subject of Research. The problem of multiharmonic disturbance compensation for the class of linear time-invariant plants with known parameters and delay is considered. Method. The disturbance is presented as unmeasurable output of linear autonomous model (exosystem with known order and unknown parameters. The problem is resolved with the use of parametrized representation of disturbance designed by means of exosystem state observer and predictor of this state that finally enables applying certainty equivalence principle. In order to remove undesirable influence of delay a modified adaptation algorithm is created. The algorithm is based on augmentation of the plant state vector and generates advanced adjustable parameters for control. As distinct from widespread approaches, the proposed algorithm does not require identification of disturbance parameters and gives the possibility to remove such restrictions as adaptation gain margin and time delay margin. Main Results. Simulation results obtained in MATLAB/Simulink environment are presented to demonstrate the performance of proposed approach. Results illustrate the boundness of all signals in the closed-loop system and complete compensation of harmonic signal. It is shown that the proposed idea makes it possible to increase the adaptation gain for different delays without system stability loss. Practical Relevance. The algorithm of adaptive compensation is recommended for the use in such problems as: the problem of control for active vibration protection devices wherein several dominating harmonics can be taken from the spectrum of vibration signal; the problems of control of robotics systems with periodical behavior; the problems of ship roll compensation; the problems of space plants control in the presence of uncontrollable rotation.

  18. Using Local Flaps in a Chest Wall Reconstruction after Mastectomy for Locally Advanced Breast Cancer

    Directory of Open Access Journals (Sweden)

    Joo Seok Park

    2015-05-01

    Full Text Available BackgroundSurgical ablation for locally advanced breast cancer results in large chest wall defects, which can then be managed with local flaps or skin grafts. The purpose of this article is to evaluate the outcomes of three types of local skin flaps.MethodsAmong 25 local flaps in 24 patients, 6 were bilateral advancement (BA flaps, 9 were thoracoabdominal (TA flaps, and 10 were thoracoepigastric (TE flaps. Clinical outcomes were compared including complications, the need for a secondary surgical intervention, and the timing of adjuvant therapy.ResultsThe mean defect size was 436.2 cm2. Two patients with TA flaps and 6 patients with TE flaps developed distal flap necrosis, and skin grafts were needed to treat 2 patients with TE flaps. Radiation was administered to the BA, TA, and TE patients after average postoperative durations of 28, 30, or 41 days, respectively. The incidence of flap necrosis tended to be higher in TE patients, which lead to significant delays in adjuvant radiation therapy (P=0.02.ConclusionsThree types of local skin flaps can be used to treat large chest wall defects after the excision of locally advanced breast cancer. Each flap has its own merits and demerits, and selecting flaps should be based on strict indications based on the dimensions and locations of the defects.

  19. Radial forearm free flap pharyngoesophageal reconstruction.

    Science.gov (United States)

    Azizzadeh, B; Yafai, S; Rawnsley, J D; Abemayor, E; Sercarz, J A; Calcaterra, T C; Berke, G S; Blackwell, K E

    2001-05-01

    This study evaluates the outcome of pharyngoesophageal reconstruction using radial forearm free flaps with regard to primary wound healing, speech, and swallowing in patients requiring laryngopharyngectomy. Retrospective review in the setting of a tertiary, referral, and academic center. Twenty patients underwent reconstruction of the pharyngoesophageal segment using fasciocutaneous radial forearm free flaps. All free flap transfers were successful. An oral diet was resumed in 85% of the patients after surgery. Postoperative pharyngocutaneous fistulas occurred in 4 patients (20%) with 3 resolving spontaneously. Distal strictures also occurred in 20% of the patients. Five patients who underwent tracheoesophageal puncture achieved useful speech. Advantages of radial forearm free flaps for microvascular pharyngoesophageal function include high flap reliability, limited donor site morbidity, larger vascular pedicle caliber, and the ability to achieve good quality tracheoesophageal speech. The swallowing outcome is similar to that achieved after jejunal flap pharyngoesophageal reconstruction. The main disadvantage of this technique relates to a moderately high incidence of pharyngocutaneous fistulas, which contributes to delayed oral intake in affected patients.

  20. Global asymptotic stability analysis for delayed neural networks using a matrix-based quadratic convex approach.

    Science.gov (United States)

    Zhang, Xian-Ming; Han, Qing-Long

    2014-06-01

    This paper is concerned with global asymptotic stability for a class of generalized neural networks with interval time-varying delays by constructing a new Lyapunov-Krasovskii functional which includes some integral terms in the form of ∫(t-h)(t)(h-t-s)(j)ẋ(T)(s)Rjẋ(s)ds(j=1,2,3). Some useful integral inequalities are established for the derivatives of those integral terms introduced in the Lyapunov-Krasovskii functional. A matrix-based quadratic convex approach is introduced to prove not only the negative definiteness of the derivative of the Lyapunov-Krasovskii functional, but also the positive definiteness of the Lyapunov-Krasovskii functional. Some novel stability criteria are formulated in two cases, respectively, where the time-varying delay is continuous uniformly bounded and where the time-varying delay is differentiable uniformly bounded with its time-derivative bounded by constant lower and upper bounds. These criteria are applicable to both static neural networks and local field neural networks. The effectiveness of the proposed method is demonstrated by two numerical examples.

  1. A Lyapunov-Razumikhin approach for stability analysis of logistics networks with time-delays

    Science.gov (United States)

    Dashkovskiy, Sergey; Karimi, Hamid Reza; Kosmykov, Michael

    2012-05-01

    Logistics network represents a complex system where different elements that are logistic locations interact with each other. This interaction contains delays caused by time needed for delivery of the material. Complexity of the system, time-delays and perturbations in a customer demand may cause unstable behaviour of the network. This leads to the loss of the customers and high inventory costs. Thus the investigation of the network on stability is desired during its design. In this article we consider local input-to-state stability of such logistics networks. Their behaviour is described by a functional differential equation with a constant time-delay. We are looking for verifiable conditions that guarantee stability of the network under consideration. Lyapunov-Razumikhin functions and the local small gain condition are utilised to obtain such conditions. Our stability conditions for the logistics network are based on the information about the interconnection properties between logistic locations and their production rates. Finally, numerical results are provided to demonstrate the proposed approach.

  2. Exponential stability for a class of state-dependent delay equations via the Crandall-Liggett approach

    Science.gov (United States)

    Louihi, M.; Hbid, M. L.

    2007-05-01

    In this paper we are concerned with the exponential asymptotic stability of the solution of a class of differential equations with state dependent delays. Our approach is based on the Crandall-Liggett approximation and the properties of semigroups.

  3. Two-Dimensional Aerodynamic Models of Insect Flight for Robotic Flapping Wing Mechanisms of Maximum Efficiency

    Institute of Scientific and Technical Information of China (English)

    Thien-Tong Nguyen; Doyoung Byun

    2008-01-01

    In the "modified quasi-steady" approach, two-dimensional (2D) aerodynamic models of flapping wing motions are analyzed with focus on different types of wing rotation and different positions of rotation axis to explain the force peak at the end of each half stroke. In this model, an additional velocity of the mid chord position due to rotation is superimposed on the translational relative velocity of air with respect to the wing. This modification produces augmented forces around the end of eachstroke. For each case of the flapping wing motions with various combination of controlled translational and rotational velocities of the wing along inclined stroke planes with thin figure-of-eight trajectory, discussions focus on lift-drag evolution during one stroke cycle and efficiency of types of wing rotation. This "modified quasi-steady" approach provides a systematic analysis of various parameters and their effects on efficiency of flapping wing mechanism. Flapping mechanism with delayed rotation around quarter-chord axis is an efficient one and can be made simple by a passive rotation mechanism so that it can be useful for robotic application.

  4. On the impact of information delay on location-based relaying: a markov modeling approach

    DEFF Research Database (Denmark)

    Nielsen, Jimmy Jessen; Olsen, Rasmus Løvenstein; Madsen, Tatiana Kozlova;

    2012-01-01

    For centralized selection of communication relays, the necessary decision information needs to be collected from the mobile nodes by the access point (centralized decision point). In mobile scenarios, the required information collection and forwarding delays will affect the reliability...... of the collected information and hence will influence the performance of the relay selection method. This paper analyzes this influence in the decision process for the example of a mobile location-based relay selection approach using a continuous time Markov chain model. The model is used to obtain optimal relay...

  5. Interpreting laser Doppler recordings from free flaps.

    Science.gov (United States)

    Svensson, H; Holmberg, J; Svedman, P

    1993-01-01

    Although the transfer of free flaps is nowadays accomplished with an increasing degree of safety, thrombosis of the microvascular anastomoses is still a problem. In order to avoid delay in re-operating, various methods for objective blood flow monitoring have been tried, among them Laser Doppler Flowmetry (LDF). When one reviews the literature, it is apparent that opinions differ about whether or not LDF is a reliable technique for this purpose. To focus on the need to interpret continuous recordings, this paper reports our findings in six latissimus dorsi free flaps chosen from our series of LDF monitoring procedures. One uneventful flap, no. 1, had an immediate postoperative LDF value of 4.5 perfusion units (PU). LDF values improved during the recovery period and the graphic recording showed fluctuations due to normal physiological variations of the blood flow in the flap. Another uneventful flap, no. 4, showed the same pattern, though at an appreciably lower level, 2 PU, on average. Flap no. 2 had an acceptably high value of 3.5 PU despite suffering a venous thrombosis. However, the LDF recording showed no fluctuations and the value declined gradually. Another flap, no. 3, showed fluctuations and blood flow was normal although the value decreased to 2.5 PU. In flap no. 5, any value between 2 and 3.5 PU could be obtained merely by adjusting the position of the probe in the holder. In no. 6, the LDF value suddenly dropped, accompanied by a decrease in the total amount of backscattered light, indicating venous obstruction which was confirmed at re-operation.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. [Emergency free flap in reconstruction of the lower limb. Thirty-five years of experience].

    Science.gov (United States)

    Bellidenty, L; Chastel, R; Pluvy, I; Pauchot, J; Tropet, Y

    2014-02-01

    Authors analyzed 89 cases (86 patients) of lower limb extensive soft tissue defects reconstruction during 1978 to 2013. The mean age is 37 years and 2 months old (range: 5-84 years old). A total of 71 males and 15 female were included. Free flaps were used in emergency in 23 cases for principally covering Gustilo 3B open lower limb fracture and in a later stage for 66 cases all referred from their center for coverage of exposed bone, with frequently osteomyelitis. About the selection of free flaps, in 47 cases we used a latissimus dorsi flaps, 12 cases of epiploon free transfer (in septic area), 10 cases of gracilis transfer and 10 serratus anterior flaps. There are one medial gastrocnemius flap, 2 composite soleus and fibular free flap, 2 antebrachial flap, one inguinal myoosteocutaneous flap, 1 transferred from the other lower limb and one inguinal cutaneous flap. There are 18 free flap losses: one in emergency and 17 after delayed reconstruction. Authors retrospectively analyzed the results (complications, osteomyelitis) according to the timing for lower extremity reconstruction. They found a low infection and flap failure rates (4%) when the coverage is made in the same operating time than initial fracture fixation, they increase to 60% for osteomyelitis and to 23% for flap failure when the reconstruction is delayed.

  7. Stability and Feedback Design of a Class of Time-Delay Systems with Discontinuity: Functional Differential Inclusion-Based Approach

    Science.gov (United States)

    Zhang, Jiangyan; Shen, Tielong

    To analyze and synthesize time-delay systems with discontinuity, the framework of differential inclusion in the sense of Filippov is extended to functional differential inclusion. Based on the extension, the concept of Filippov solution is introduced for the time-delay systems with discontinuity at first, and then it is shown that both the Lyapunov stability and the LaSalle invariance principle results can be extended to such kind of systems. Moreover, by using the proposed analysis tools, a stabilization feedback design approach is proposed for a class of nonlinear time-delay systems with discontinuity. Simulation results of numerical examples are given to demonstrate the proposed control approaches.

  8. Predictive risk factors of free flap thrombosis in breast reconstruction surgery.

    Science.gov (United States)

    Masoomi, Hossein; Clark, Emily G; Paydar, Keyianoosh Z; Evans, Gregory R D; Nguyen, Audrey; Kobayashi, Mark R; Wirth, Garrett A

    2014-11-01

    Vascular thrombosis is one of the major postoperative complications of free flap microvascular breast reconstruction operations. It is associated with higher morbidity, higher cost, increased length of hospital stay, and potentially flap loss. Our purpose is to evaluate the rate of this complication and whether patient characteristics play a role. Using the Nationwide Inpatient Sample (NIS) database, we examined the clinical data of patients who underwent free flap breast reconstruction between 2009 and 2010 in the United States. Multivariate and univariate regression analyses were performed to identify independent risk factors of flap thrombosis. A total of 15,211 patients underwent free flap breast reconstruction surgery (immediate reconstruction: 43%). The most common flap was the free deep inferior epigastric perforator (DIEP) flap (53.6%), followed by free transverse rectus abdominis myocutaneous (TRAM) flap (43.1%), free superficial inferior epigastric artery (SIEA) flap (2%), and free gluteal artery perforator (GAP) flap (1.3%). The overall rate of flap thrombosis was 2.4 %, with the highest rate seen in the SIEA group (11.4%) and the lowest in the TRAM group (1.7%). Peripheral vascular disease (adjusted odds ration [AOR] 10.61), SIEA flap (AOR, 4.76) and delayed reconstruction (AOR, 1.42) were found to be statistically significant risk factors for flap thrombosis. Other comorbidities were not linked. While the overall rate of flap thrombosis in free flap breast reconstruction was relatively low (2.4%), Plastic Surgeons should be aware that patients with peripheral vascular disease and those undergoing free SIEA flap are at higher risk of flap thrombosis and they should closely monitor flaps to increase the chance for early salvage.

  9. A time delay artificial neural network approach for flow routing in a river system

    Directory of Open Access Journals (Sweden)

    M. J. Diamantopoulou

    2006-09-01

    Full Text Available River flow routing provides basic information on a wide range of problems related to the design and operation of river systems. In this paper, three layer cascade correlation Time Delay Artificial Neural Network (TDANN models have been developed to forecast the one day ahead daily flow at Ilarionas station on the Aliakmon river, in Northern Greece. The networks are time lagged feed-formatted with delayed memory processing elements at the input layer. The network topology is using multiple inputs, which include the time lagged daily flow values further up at Siatista station on the Aliakmon river and at Grevena station on the Venetikos river, which is a tributary to the Aliakmon river and a single output, which are the daily flow values at Ilarionas station. The choice of the input variables introduced to the input layer was based on the cross-correlation. The use of cross-correlation between the ith input series and the output provides a short cut to the problem of the delayed memory determination. Kalman's learning rule was used to modify the artificial neural network weights. The networks are designed by putting weights between neurons, by using the hyperbolic-tangent function for training. The number of nodes in the hidden layer was determined based on the maximum value of the correlation coefficient. The results show a good performance of the TDANN approach for forecasting the daily flow values, at Ilarionas station and demonstrate its adequacy and potential for river flow routing. The TDANN approach introduced in this study is sufficiently general and has great potential to be applicable to many hydrological and environmental applications.

  10. A novel approach to delayed-start analyses for demonstrating disease-modifying effects in Alzheimer's disease.

    Directory of Open Access Journals (Sweden)

    Hong Liu-Seifert

    Full Text Available One method for demonstrating disease modification is a delayed-start design, consisting of a placebo-controlled period followed by a delayed-start period wherein all patients receive active treatment. To address methodological issues in previous delayed-start approaches, we propose a new method that is robust across conditions of drug effect, discontinuation rates, and missing data mechanisms. We propose a modeling approach and test procedure to test the hypothesis of noninferiority, comparing the treatment difference at the end of the delayed-start period with that at the end of the placebo-controlled period. We conducted simulations to identify the optimal noninferiority testing procedure to ensure the method was robust across scenarios and assumptions, and to evaluate the appropriate modeling approach for analyzing the delayed-start period. We then applied this methodology to Phase 3 solanezumab clinical trial data for mild Alzheimer's disease patients. Simulation results showed a testing procedure using a proportional noninferiority margin was robust for detecting disease-modifying effects; conditions of high and moderate discontinuations; and with various missing data mechanisms. Using all data from all randomized patients in a single model over both the placebo-controlled and delayed-start study periods demonstrated good statistical performance. In analysis of solanezumab data using this methodology, the noninferiority criterion was met, indicating the treatment difference at the end of the placebo-controlled studies was preserved at the end of the delayed-start period within a pre-defined margin. The proposed noninferiority method for delayed-start analysis controls Type I error rate well and addresses many challenges posed by previous approaches. Delayed-start studies employing the proposed analysis approach could be used to provide evidence of a disease-modifying effect. This method has been communicated with FDA and has been

  11. Some numerical approaches of creep, thermal shock, damage and delayed failure of ceramics and refractories

    Indian Academy of Sciences (India)

    Michel Boussuge

    2001-04-01

    Numerical simulation is now very often used to predict the behaviour of components in service conditions. This paper is interested in specific approaches concerning ceramic materials and refractories. Creep can be satisfactorily described by a kinematic hardening, and exhibits different creep rates in tension and compression. Concerning the thermal shock of materials, the numerical approach depends whether or not the material is able to develop a sprayed out damage, leading to micro- or macro-cracking. Finally, delayed failure at high temperature can be considered as a consequence of creep, but the random aspect of failure seriously complicates the numerical models. The lack of experimental data presently limits the calibration and the validation of the numerical models.

  12. An improved LMI-based approach for stability of piecewise affine time-delay systems with uncertainty

    Science.gov (United States)

    Duan, Shiming; Ni, Jun; Galip Ulsoy, A.

    2012-09-01

    The stability problem for uncertain piecewise affine (PWA) time-delay systems is investigated in this article. It is assumed that there exists a known constant time delay in the system and the uncertainly is norm-bounded. Sufficient conditions for the stability of nominal systems and the stability of systems subject to uncertainty are derived using the Lyapunov-Krasovskii functional with a triple integration term. This approach handles switching based on the delayed states (in addition to the states) for a PWA time-delay system, considers structured as well as unstructured uncertainty and reduces the conservativeness of previous approaches. The effectiveness of the proposed approach is demonstrated by comparing with the existing methods through numerical examples.

  13. Early versus delayed rehabilitation treatment in hemiplegic patients with ischemic stroke: proprioceptive or cognitive approach?

    Science.gov (United States)

    Morreale, Manuela; Marchione, Pasquale; Pili, Antonio; Lauta, Antonella; Castiglia, Stefano F; Spallone, Aldo; Pierelli, Francesco; Giacomini, Patrizia

    2016-02-01

    Early/intensive mobilization may improve functional recovery after stroke but it is not clear which kind of "mobilization" is more effective. Proprioceptive neuromuscular facilitation (PNF) and cognitive therapeutic exercise (CTE) are widespread applied in post-stroke rehabilitation but their efficacy and safety have not been systematically investigated. To compare PNF and CTE methods in a two different time setting (early versus standard approach) in order to evaluate different role of time and techniques in functional recovery after acute ischemic stroke. We designed a prospectical multicenter blinded interventional study of early versus standard approach with two different methods by means of both PNF and CTE. A discrete stroke-dedicated area for out-of-thrombolysis patients, connected with two different comprehensive stroke centres in two different catchment areas. Three hundred and forty consecutive stroke patient with first ever sub-cortical ischemic stroke in the mean cerebral artery (MCA) territory and contralateral hemiplegia admitted within 6 and 24 hours from symptoms onset. All patients were randomly assigned by means of a computer generated randomization sequence in blocks of 4 to one to the 4 interventional groups: early versus delayed rehabilitation programs with Kabat's schemes or Perfetti's technique. Patients in both delayed group underwent to a standard protocol in the acute phase. disability at 3-12 months. Disability measures: modified Rankin Score and Barthel Index. Safety outcome: immobility-related adverse events. Six-Minute Walking Test, Motricity Index, Mini-Mental State Examination, Beck Depression Inventory. Disability was not different between groups at 3 months but Barthel Index significantly changed between early versus delayed groups at 12 months (P=0.01). Six-Minute Walking Test (P=0.01) and Motricity Index in both upper (P=0.01) and lower limbs (P=0.001) increased in early versus delayed groups regardless rehabilitation schedule. A

  14. Monitoring of free TRAM flaps with microdialysis.

    Science.gov (United States)

    Udesen, A; Løntoft, E; Kristensen, S R

    2000-02-01

    The aim of this investigation was to follow the metabolism of free TRAM flaps using microdialysis. Microdialysis is a new sampling technique that provide opportunities to follow the biochemistry in specific organs or tissues. A double-lumen microdialysis catheter or probe, with a dialysis membrane at the end, is introduced into the specific tissue. Perfusion fluid is slowly pumped through the catheter and equilibrates across the membrane with surrounding extracellular concentrations of low molecular weight substances. The dialysate is collected in microvials and analyzed by an instrument using very small volumes. Glucose, glycerol, and lactate concentrations were measured in the flaps and compared with those in a reference catheter that was placed subcutaneously in the femur. The investigation continued 72 hr postoperatively. The study group consisted of 14 women who underwent reconstruction with a free TRAM flap, and one woman with a double TRAM flap. During flap ischemia, the concentration of glucose was reduced, while the lactate and glycerol levels increased. The differences between the flaps and controls were statistically highly significant. After reperfusion of the flaps, the concentrations of glucose, lactate, and glycerol approached normal. One flap failed because of an arterial anastomosis thrombosis. This was clearly demonstrated by the samples from the microdialysis: the concentration of glucose fell to an unmeasurable level; the concentration of lactate increased for a period before it stopped due to lack of glucose; and the concentration of glycerol increased to a very high level, probably because ischemia caused damage to the cell membranes of which glycerol is an important part. The authors concluded that microdialysis can detect ischemia in free flaps at an early stage, making early surgical intervention possible.

  15. Robust Fault Estimation for a Class of T-S Fuzzy Singular Systems with Time-Varying Delay via Improved Delay Partitioning Approach

    Directory of Open Access Journals (Sweden)

    Chao Sun

    2016-01-01

    Full Text Available The problem of delay-dependent robust fault estimation for a class of Takagi-Sugeno (T-S fuzzy singular systems is investigated. By decomposing the delay interval into two unequal subintervals and with a new and tighter integral inequality transformation, an improved delay-dependent stability criterion is given in terms of linear matrix inequalities (LMIs to guarantee that the fuzzy singular system with time-varying delay is regular, impulse-free, and stable firstly. Then, based on this criterion, by considering the system fault as an auxiliary disturbance vector and constructing an appropriate fuzzy augmented system, a fault estimation observer is designed to ensure that the error dynamic system is regular, impulse-free, and robustly stable with a prescribed H∞ performance satisfied for all actuator and sensor faults simultaneously, and the obtained fault estimates can practically better depict the size and shape of the faults. Finally, numerical examples are given to show the effectiveness of the proposed approach.

  16. New Therapeutic Approaches to Prevent or Delay Beta-Cell Failure in Diabetes

    Directory of Open Access Journals (Sweden)

    Ionica Floriana Elvira

    2015-09-01

    Full Text Available Background and aims: The most recent estimates of International Diabetes Federation indicate that 382 million people have diabetes, and the incidence of this disease is increasing. While in type 1 diabetes mellitus (T1DM beta-cell death is autoimmunemediated, type 2 diabetes mellitus (T2DM results from an interaction between genetic and environmental factors that impair beta-cell function and insulin action. Many people with T2DM remain unaware of their illness for a long time because symptoms may take years to appear or be recognized, while the body is affected by excess blood glucose. These patients are often diagnosed only when diabetes complications have already developed. The aim of this article was to perform a review based on literature data on therapeutic modalities to prevent/delay beta cell function decline. Material and Methods: We searched MEDLINE from 2000 to the present to identify the therapeutic approaches to prevent or delay beta-cell failure in patients with T2DM. Results and conclusions: Several common polymorphisms in genes linked to monogenic forms of diabetes appear to influence the response to T2DM pharmacotherapy. Recent studies report the role of the G protein coupled receptor 40 (GPR40, also known as Free Fatty Acids Receptor 1 (FFAR1 in the regulation of beta-cell function- CNX-011-67 (a GPR40 agonist has the potential to provide good and durable glycemic control in T2DM patients.

  17. Reconstruction of weightbearing forefoot defects with digital artery flaps.

    Science.gov (United States)

    Liu, Lifeng; Cao, Xuecheng; Cai, Jinfang

    2015-01-01

    Reconstruction of a defect of the weightbearing forefoot region remains a challenging problem owing to the limited alternatives available. The digital artery flap can be used for coverage of defects in the weightbearing forefoot. The present study reports our results using a digital artery flap for reconstruction of soft tissue defects of the weightbearing forefoot in 8 patients. The mean patient age was 35 ± 11.3 years. The etiology of the soft tissue defects included 4 (50%) traumatic events, 2 (25%) dysfunctional scars, and 2 (25%) neuropathic ulcerations. The mean postoperative follow-up duration was 22 ± 11.1 months (range 12 months to 4 years). All 8 flaps survived successfully. The complications included 1 case of delayed healing of a neuropathic ulceration. The digital artery flap is a good alternative for soft tissue defects of the weightbearing forefoot. The surgical techniques for harvesting the flaps are easy to manage.

  18. Admissibility analysis for discrete-time singular systems with randomly occurring uncertainties via delay-divisioning approach.

    Science.gov (United States)

    Jarina Banu, L; Balasubramaniam, P

    2015-11-01

    This paper deals with the problem of admissibility analysis for discrete-time singular system with time-delays. The uncertainties occurring in the system parameters are assumed to be random. By constructing Lyapunov functional, sufficient delay-dependent stochastic admissibility conditions are established via delay divisioning approach in terms of linear matrix inequalities (LMIs), which can be easily checked by utilizing the numerically efficient Matlab LMI toolbox. Numerical examples and their simulation results are given to illustrate the effectiveness of the obtained theoretical results.

  19. An linear matrix inequality approach to global synchronisation of non-parameter perturbations of multi-delay Hopfield neural network

    Institute of Scientific and Technical Information of China (English)

    Shao Hai-Jian; Cai Guo-Liang; Wang Hao-Xiang

    2010-01-01

    In this study,a successful linear matrix inequality approach is used to analyse a non-parameter perturbation of multi-delay Hopfield neural network by constructing an appropriate Lyapunov-Krasovskii functional.This paper presents the comprehensive discussion of the approach and also extensive applications.

  20. Interpretation of delayed neutron emission using a non-statistical approach

    CERN Document Server

    Shihab-Eldin, A A; Nuh, F M; Prussin, S G

    1976-01-01

    Experimental data on several delayed neutron emitting systems exhibit characteristics not accounted for by the normal statistical model. Using a single-particle approach, the locations and relative beta - strengths to configurations in the emitter nuclides populated by allowed G.T. transitions have been calculated and are in qualitative agreement with strength function data for /sup 85/As, /sup 87/Br, /sup 135/Sb and /sup 137/I. Calculations of P/sub n/-values for the bromine precursors A=87 to 92 are also in good agreement with experimental data. The lack of high energy neutrons in spectra where excited states in the final nucleus are strongly populated can be traced qualitatively to particle-hole excitations contributing to the excited states. (16 refs).

  1. The submental island flap.

    Science.gov (United States)

    Sterne, G D; Januszkiewicz, J S; Hall, P N; Bardsley, A F

    1996-03-01

    The submental island flap is a reliable source of skin of excellent colour, contour and texture match for facial resurfacing and leaves a well hidden donor site. The flap is safe, rapid and simple to raise. We report on its use in 12 cases of facial or intraoral reconstruction. Complications were few. However, there was one case of complete flap loss following its use in a reverse flow manner, due to the presence of an unreported, but constant, valve in the venous system of the face. We believe this flap to be a worthwhile addition to the existing surgical armamentarium.

  2. Propeller TAP flap

    DEFF Research Database (Denmark)

    Thomsen, Jørn Bo; Bille, Camilla; Wamberg, Peter

    2013-01-01

    The aim of this study was to examine if a propeller thoracodorsal artery perforator (TAP) flap can be used for breast reconstruction. Fifteen women were reconstructed using a propeller TAP flap, an implant, and an ADM. Preoperative colour Doppler ultrasonography was used for patient selection...... major complications needing additional surgery. One flap was lost due to a vascular problem. Breast reconstruction can be performed by a propeller TAP flap without cutting the descending branch of the thoracodorsal vessels. However, the authors would recommend that a small cuff of muscle is left around...

  3. Immediate versus Delayed Sarcoma Reconstruction: Impact on Outcomes

    Directory of Open Access Journals (Sweden)

    Kyle J. Sanniec

    2016-01-01

    Full Text Available Background. Sarcoma is a rare malignancy, and more recent management algorithms emphasize a multidisciplinary approach and limb salvage, which has resulted in an increase in overall survival and limb preservation. However, limb salvage has resulted in a higher rate of wound complications. Objective. To compare the complications between immediate and delayed (>three weeks reconstruction in the multidisciplinary limb salvage sarcoma patient population. Methods. A ten-year retrospective review of patients who underwent sarcoma resection was performed. The outcome of interest was wound complication in the postoperative period based on timing of reconstruction. We defined infection as any infection requiring intravenous antibiotics, partial flap failure as any flap requiring a debridement or revision, hematoma/seroma as any hematoma/seroma requiring drainage, and wound dehiscence as a wound that was not completely intact by three weeks postoperatively. Results. 70 (17 delayed, 53 immediate patients who underwent sarcoma resection and reconstruction met the inclusion criteria. Delayed reconstruction significantly increased the incidence of postoperative wound infection and wound dehiscence. There was no difference in partial or total flap loss, hematoma, or seroma between the two groups. Discussion and Conclusion. Immediate reconstruction results in decreased wound complications may reduce the morbidity associated with multidisciplinary treatment in the limb salvage sarcoma patient.

  4. The 727 approach energy management system avionics specification (preliminary)

    Science.gov (United States)

    Jackson, D. O.; Lambregts, A. A.

    1976-01-01

    Hardware and software requirements for an Approach Energy Management System (AEMS) consisting of an airborne digital computer and cockpit displays are presented. The displays provide the pilot with a visual indication of when to manually operate the gear, flaps, and throttles during a delayed flap approach so as to reduce approach time, fuel consumption, and community noise. The AEMS is an independent system that does not interact with other navigation or control systems, and is compatible with manually flown or autopilot coupled approaches. Operational use of the AEMS requires a DME ground station colocated with the flight path reference.

  5. Breast Reconstruction Using Tram Flap: Prospective Outcome and Complications

    Directory of Open Access Journals (Sweden)

    Homayoon Zehtab

    2006-07-01

    Full Text Available Background:The transverse rectus abdominis musculocutaneous TRAM flap remains the gold standard for postmastectomy reconstruction either immediate or delayed.However,transfer of TRAM flap can be associated with donor site morbidities and complications in flap.A successful reconstruction consists of careful patient selection, surgical technique and meticulous preoperative planning.This study was designed to evaluate outcome and complications of breast reconstruction with TRAM flap in association with patient conditions and risk factors, prospectively. Methods: Breast reconstruction was performed in 44 women consecutively,using the TRAM flap during a 3-year period, 1999–2002. Modified radical mastectomy accompanying immediate reconstructions with TRAM flap was performed for 12 patients and delayed reconstruction was used for other patients with previous mastectomy. Results: The mean age of the patients was 40.41±4.43 years. Thirty (68.18% patients had comorbidities, consisting of radiation therapy, obesity, hypertension, diabetes mellitus, smoking and abdominal scar. Contralateral and ipsilateral TRAM flaps were used in 26(59.09% and 14(31.81% reconstructions, respectively. The abdominal defect was repaired in layers with the use of synthetic mesh in 30(68.18% patients. The overall complication rate was 31.82%, such as fat necrosis (15.91%, partial flap loss (13.64%, etc. Satisfaction rates were excellent in 10 (22.72%, good in 25 (56.82%, moderate in five (11.36%, and poor in four (9.09% patients. The mean of postoperative inpatient hospital days were 15.18±4.89 and 14.28±6.52 in patients with contralateral and ipsilateral flaps,respectively (p>0.05.A significant association was observed between overall complications and comorbidities. Partial flap loss and fat necrosis was associated with smoking, and abdominal hernia was associated with obesity marginally.Conclusions:The outcome of breast reconstruction using TRAM flap is similar by

  6. Surgical exploration of 71 free flaps in crisis following head and neck reconstruction.

    Science.gov (United States)

    Yang, X; Li, S; Wu, K; Hu, L; Liu, W; Ji, T; Hu, Y; Xu, L; Sun, J; Zhang, Z; Zhang, C

    2016-02-01

    The medical records of patients who had undergone a free flap reconstruction after radical resection of oral cancer between January 2009 and December 2013 at the study hospital in China were reviewed retrospectively. Of the 1550 patients who underwent free flap reconstructions, 71 were explored for suspected flap compromise caused by postoperative thrombosis. Patient demographic data, clinicopathological data of the tumour, details of the free flaps, and operative findings were assessed, and the medical records were analyzed to identify the reasons for intervention and the outcomes. Of the 71 flaps in crisis, 47 (66.2%) were salvaged. Free flap failure was 6.2-times more likely to develop in patients undergoing surgical exploration after 72 h (95% confidence interval 2.090-18.197, P=0.001). Of the 19 flaps identified as subject to delayed exploration, 14 failed and three had partial necrosis. Free flap failure was 3.4-times more likely to develop in patients with perforator flaps (95% confidence interval 1.222-9.719, P=0.019). The early detection of free flap failure is critical to flap salvage. The salvage success rate decreases significantly at >72 h after the initial operation. It appears to be more difficult to salvage a perforator flap.

  7. An alternative approach to calculating Area-Under-the-Curve (AUC) in delay discounting research.

    Science.gov (United States)

    Borges, Allison M; Kuang, Jinyi; Milhorn, Hannah; Yi, Richard

    2016-09-01

    Applied to delay discounting data, Area-Under-the-Curve (AUC) provides an atheoretical index of the rate of delay discounting. The conventional method of calculating AUC, by summing the areas of the trapezoids formed by successive delay-indifference point pairings, does not account for the fact that most delay discounting tasks scale delay pseudoexponentially, that is, time intervals between delays typically get larger as delays get longer. This results in a disproportionate contribution of indifference points at long delays to the total AUC, with minimal contribution from indifference points at short delays. We propose two modifications that correct for this imbalance via a base-10 logarithmic transformation and an ordinal scaling transformation of delays. These newly proposed indices of discounting, AUClog d and AUCor d, address the limitation of AUC while preserving a primary strength (remaining atheoretical). Re-examination of previously published data provides empirical support for both AUClog d and AUCor d . Thus, we believe theoretical and empirical arguments favor these methods as the preferred atheoretical indices of delay discounting.

  8. Esthetic and functional reconstruction of the posttumoral interrupted mandible with double-barrel fibular free flap graft: rationale for a microsurgical and prosthodontic approach.

    Science.gov (United States)

    Paranque, Armand-Régis; Steve, Marc; Vazquez, Lydia; Bolleyn, Alain; Roze-Pellat, Marie-Andrée; Dohan Ehrenfest, David M

    2011-10-01

    Reconstruction after substantial osseous, cutaneous, and muscular tissue loss following a mandibular resection is a challenge. The use of a fibular free flap is an outstanding, but delicate, treatment option. These grafts, using the double-barrel technique, can achieve an almost complete reconstruction of the mandibular defect. The challenge posed by these treatments is to achieve an end result that is both functional and esthetically pleasing-an endeavor that requires a defined prosthetic plan prior to complete microsurgical reconstruction. Using a detailed clinical case, this article discusses the importance of planning the mandible reconstruction with double-barrel fibular graft in view of an implant-supported fixed partial denture. Immediate implant loading was even possible in this case. This approach allows improvement of the final esthetic and functional result of such a complex rehabilitation. Maxillofacial reconstructive surgery should seek to establish a near-as-normal anatomic situation that will allow a permanent implant rehabilitation that is both esthetic and durable.

  9. A unified approach for proportional-integral-derivative controller design for time delay processes

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuzzoha, Mohammad [King Fahd University of Petroleum and Minerals, Dhahran (Saudi Arabia)

    2015-04-15

    An analytical design method for PI/PID controller tuning is proposed for several types of processes with time delay. A single tuning formula gives enhanced disturbance rejection performance. The design method is based on the IMC approach, which has a single tuning parameter to adjust the performance and robustness of the controller. A simple tuning formula gives consistently better performance as compared to several well-known methods at the same degree of robustness for stable and integrating process. The performance of the unstable process has been compared with other recently published methods which also show significant improvement in the proposed method. Furthermore, the robustness of the controller is investigated by inserting a perturbation uncertainty in all parameters simultaneously, again showing comparable results with other methods. An analysis has been performed for the uncertainty margin in the different process parameters for the robust controller design. It gives the guidelines of the M{sub s} setting for the PI controller design based on the process parameters uncertainty. For the selection of the closed-loop time constant, (τ{sub c}), a guideline is provided over a broad range of θ/τ ratios on the basis of the peak of maximum uncertainty (M{sub s}). A comparison of the IAE has been conducted for the wide range of θ/τ ratio for the first order time delay process. The proposed method shows minimum IAE in compared to SIMC, while Lee et al. shows poor disturbance rejection in the lag dominant process. In the simulation study, the controllers were tuned to have the same degree of robustness by measuring the M{sub s}, to obtain a reasonable comparison.

  10. Cervicofacial flap revisited

    Directory of Open Access Journals (Sweden)

    Dhananjay V. Nakade

    2016-11-01

    Conclusions: Cervicofacial flap is simple, easy to operate, consume less operating time as compared to microvascular flap. It is less complicated and especially useful in diabetic, hypertensives and old debilitated patients with high risk of anaesthesia. [Int J Res Med Sci 2016; 4(11.000: 4669-4674

  11. The use of the pedicled supraclavicular flap in noma reconstructive surgery.

    Science.gov (United States)

    Hartman, Ed H M; Van Damme, Philip A; Sauter, Hartwig; Suominen, Sinikka H H

    2006-01-01

    Three noma patients with large unilateral facial defects were reconstructed using the pedicled supraclavicular flap technique in the Noma Children Hospital in Sokoto, Nigeria. The results are-although not completely perfect-encouraging enough to report and to repeat the technique in future reconstructive noma surgery after moderate modifications. It is advised not to tunnel the pedicle in the neck, but instead to open the neck. Then, the flap can be inset in a Z-plasty fashion to close the neck without the chance of compression of the pedicle of the flap. In this way flap necrosis can be prevented, without the risk of a scar contracture of the neck. Another technique, which can prevent partial flap necrosis and loss of tissue, with the need for secondary stage interventions, is a delay procedure of the flap. Incorporation of the fascia in the pedicled supraclavicular flap can be another option to fulfil the abovementioned requirements.

  12. Stability and Time Delay Tolerance Analysis Approach for Networked Control Systems

    Directory of Open Access Journals (Sweden)

    Ashraf F. Khalil

    2015-01-01

    Full Text Available Networked control system is a research area where the theory is behind practice. Closing the feedback loop through shared network induces time delay and some of the data could be lost. So the network induced time delay and data loss are inevitable in networked control Systems. The time delay may degrade the performance of control systems or even worse lead to system instability. Once the structure of a networked control system is confirmed, it is essential to identify the maximum time delay allowed for maintaining the system stability which, in turn, is also associated with the process of controller design. Some studies reported methods for estimating the maximum time delay allowed for maintaining system stability; however, most of the reported methods are normally overcomplicated for practical applications. A method based on the finite difference approximation is proposed in this paper for estimating the maximum time delay tolerance, which has a simple structure and is easy to apply.

  13. A new approach to consensus problems in discrete-time multiagent systems with time-delays

    Institute of Scientific and Technical Information of China (English)

    WANG Long; XIAO Feng

    2007-01-01

    In this paper, consensus problems in discrete-time multiagent systems with timeinvariant delays are considered. In order to characterize the structures of communication topologies, the concept of "pre-leader-follower" decomposition is introduced.Then, a necessary and sufficient condition for state consensus is established. By this method, consensus problems in networks with a single time-delay, as well as with multiple time-delays, are studied, and some necessary and sufficient conditions for solvability of consensus problems are obtained.

  14. Admissibility analysis for linear singular systems with time-varying delays via neutral system approach.

    Science.gov (United States)

    Liu, Zhou-Yang; Lin, Chong; Chen, Bing

    2016-03-01

    This paper studies the admissibility problem for a class of linear singular systems with time-varying delays. In order to highlight the relations between the delay and the state, the singular system is transformed into a neutral form. Then, an appropriate type of Lyapunov-Krasovskii functionals is proposed to develop a delay-derivative-dependent admissibility condition in terms of linear matrix inequalities. The derivation combines the Wirtinger-based inequality and reciprocally convex combination method. The present criterion is also for the stability test of retarded and neutral systems with time-varying delays. Some examples are provided to illustrate the effectiveness and the benefits of the proposed method.

  15. Stability and Performance of First-Order Linear Time-Delay Feedback Systems: An Eigenvalue Approach

    Directory of Open Access Journals (Sweden)

    Shu-An He

    2011-01-01

    Full Text Available Linear time-delay systems with transcendental characteristic equations have infinitely many eigenvalues which are generally hard to compute completely. However, the spectrum of first-order linear time-delay systems can be analyzed with the Lambert function. This paper studies the stability and state feedback stabilization of first-order linear time-delay system in detail via the Lambert function. The main issues concerned are the rightmost eigenvalue locations, stability robustness with respect to delay time, and the response performance of the closed-loop system. Examples and simulations are presented to illustrate the analysis results.

  16. Differentiated Adipose-derived Stem Cells Promote Reinnervation of Rat Skin Flaps

    Directory of Open Access Journals (Sweden)

    Koichi Tomita, MD, PhD

    2013-06-01

    Conclusions: dASCs could improve flap reinnervation by 2 mechanisms: First, neurotrophic factors produced by dASCs facilitated regrowth of cutaneous axons from the surroundings of flap. Second, nerve growth factor released by dASCs induced the collateral sprouting of undamaged axons in adjacent tissues. In addition to the use of innervated flaps, dASC transplantation therapy could be a new approach to improve the sensory recovery of skin flaps.

  17. Effectiveness of Contrasting Approaches to Response-Contingent Learning among Children with Significant Developmental Delays and Disabilities

    Science.gov (United States)

    Raab, Melinda; Dunst, Carl J.; Hamby, Deborah W.

    2016-01-01

    Findings from a randomized controlled design study of an ability-based versus needs-based approach to response-contingent learning among children with significant developmental delays and disabilities who did not use instrumental behavior to produce reinforcing consequences are reported. The ability-based intervention and needs-based intervention…

  18. Delayed eruption of maxillary permanent central incisors as a consequence of mesiodens: a surgical re-treatment approach.

    Science.gov (United States)

    Moraes, Renata Simões; Farinhas, João Alfredo; Gleiser, Rogerio; Primo, Laura Guimarães

    2004-01-01

    The presence of mesiodens can cause some clinical problems. This paper reports a case of delayed eruption of permanent central incisors in a nine-year-old male as a consequence of a mesiodens and three surgical approaches prior to the eruption of incisors, which occurred after the third surgery when the crown was exposed and submitted to a gentle luxation.

  19. APPLIED ANATOMIC STUDY ON MUSCLE BONE FLAP OF ORBITOZYGOMATIC APPROACH%肌骨瓣眶颧入路的应用解剖学研究

    Institute of Scientific and Technical Information of China (English)

    张龙; 冯继; 刘银凤; 杨大伟; 李玉斌; 王永恒

    2014-01-01

    目的:对肌骨瓣眶颧入路进行解剖学研究,减少因传统眶颧入路造成的面神经颞支损伤及术后颞肌萎缩、颞窝塌陷的发生。方法:20侧尸头模拟肌骨瓣眶颧手术入路,观察术区面神经颞支和颞浅动脉额颞支的位置关系并测量二者之间的最短距离,测量MacCarty孔中心至额蝶缝的垂线距离和垂直点距额蝶缝末端的距离。结果:术区中面神经颞支均在颞浅动脉额颞支前下方走行,二者之间的最短距离为(4.80±2.40)mm, MacCarty孔位于额蝶缝上方,MacCarty孔中心距额蝶缝的垂直距离为(6.10±2.32)mm,垂直点至额蝶缝末端的距离为(22.42±4.12)mm。结论:颞浅动脉额颞支可做为筋膜间入路的解剖学标志;肌骨瓣血管神经保持完整降低了颞肌和骨萎缩的风险。%Objective:To reduce the incidence of temporal branch of facial nerve injury, temporal muscle atrophy and temporal fossa collapse induced by traditional orbitozygomatic approach.Methods:The muscle bone flap of orbitozygomatic approach was simulated in 20 sides cadaver heads.The relationship between temporal branch of facial nerve and frontotemporal branch of superficial temporal artery was observed and the shortest distance between them was measured. The vertical distance from the center of MacCarty keyhole to spheno-frontal suture, and the distance between the vertical point and the end of spheno-frontal suture were measured. Results:In surgical site, all the temporal branch of facial nerve ran anteroinferior to the frontotemporal branch of superficial temporal artery, and the shortest distance between them was (4.80±2.40)mm. The MacCarty keyhole was superior to the spheno-frontal suture, the vertical distance between the center of MacCarty keyhole and the spheno-frontal suture was (6.10±2.32)mm, the distance between the vertical point and the end of spheno-frontal suture was (22.42±4.12)mm.Conclusions:Frontotemporal branch of

  20. A Simple Superresolution Approach of Multipath Delay Profiles Measured by PN Correlation Method

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Time resolution of multipath delay profiles measured by using autocorrelation of pseudonoise (PN) code sequence is generally limitec by the chip rate of the PN code sequence. In this paper, we propose a simple method to improve the time resolution of delay profiles measured by the PN correlation method. Effectiveness of this method is demonstrated by indoor wireless propagation experiments.

  1. Reconstruction of an extended defect in the axilla using a thoracodorsal fasciocutaneous perforator flap

    NARCIS (Netherlands)

    Visconti, Giuseppe; Eltahir, Yassir; Van Ginkel, Robert J; Werker, Paul M N

    2008-01-01

    BACKGROUND: Ectopic primary carcinoma of breast tissue is a rare entity, and its diagnosis often is delayed. The axilla is the most common site involved. The Limberg flap as a random flap is easy and practicable for coverage of many defects including those involving the axilla. In the reported case,

  2. A bio-economic application to the Cape Rock Lobster resource using a delay difference modelling approach

    Directory of Open Access Journals (Sweden)

    E Roos

    2004-06-01

    Full Text Available In many species, like the Cape Rock Lobster (Jasus lalandii, the life cycles of males and females differ. This may motivate the use of two-sex models in a stock-assessment analysis. It is also true for this resource, that juveniles do not reach sexual maturity immediately. Therefore a delay-difference model is appropriate. In this study we follow a bio-economic approach and use a two-sex delay-difference model to determine a maximum economic yield strategy. Thus we determine an economic optimum steady state solution at which to harvest this resource subject to the biological constraints of the species.

  3. The effect of diode laser treatment for hair removal of post-auricular reconstruction with autologous costal cartilage grafts and delaying postauricular skin flap%半导体激光治疗耳后延迟皮瓣加自体肋软骨立体支架法耳再造术后耳廓多毛疗效观察

    Institute of Scientific and Technical Information of China (English)

    吴子涵; 李高峰; 谭军; 丁卫; 张帆

    2015-01-01

    目的:观察半导体激光对耳后延迟皮瓣加自体肋软骨立体支架法耳再造术后耳廓多毛的治疗效果。方法:使用美国科医人(Lumenis)公司Lightsheer 800 nm半导体激光进行治疗。耳后延迟皮瓣加自体肋软骨立体支架法耳再造术III期手术后1~3个月开始行激光脱毛治疗。结果:19例患者通过1~7次的脱毛治疗,均取得了良好的效果,治疗期间无严重的不良反应。结论:Lightsheer 800 nm半导体激光对耳后延迟皮瓣加自体肋软骨立体支架法耳再造术后耳廓多毛的治疗效果良好,使再造耳的形态更美观。%Objective To observe the effect of diode laser treatment for hair removal of post-auricular reconstruction with autologous costal cartilage grafts and delaying postauricular skin flap. Methods To use Lightsheer,800nm diode laser to perform the treatment.Hair removal treatment was performed after the third phase operation of auricular reconstruction with autologous costal cartilage grafts and delaying postauricular skin flap. Results All of 19 patients got good result after hair removal treatment after 1 to 7 times.No serious complications occur during treatment. Conclusion Lightsheer,800nm diode laser is a safe and effective treatment of hair removal after auricular reconstruction with autologous costal cartilage grafts and delaying postauricular skin flap. That makes the shape of reconstructive ear preferable.

  4. Preventive transposition of anterior tibial myofascial flaps for tibial fractures with delayed skin necrosis%预防性胫前肌-筋膜瓣转位在并发延迟皮肤坏死的胫骨骨折患者的应用

    Institute of Scientific and Technical Information of China (English)

    简超; 陶圣祥; 谭金海; 丁帆; 许刚; 阿米特

    2014-01-01

    Objective To discuss the effect of preventive transposition of anterior tibial myofas-cial flaps for tibial fractures complicated with severe skin and soft tissue injuries and delayed necrosis. Methods Fourteen cases of tibial fractures with severe skin and soft tissue injuries were selected for one-stage fixation combined with preventive transposition of anterior tibial myofascial flaps. The skin was cov-ered with grafts followed after the occurrence of delayed necrosis. Wound healing,fracture healing and com-plications were closely observed. Results All wounds got healed without any infective complications. Thir-teen cases were followed up and all fractures healed without bone exposure,osteomyelitis and other compli-cations. One case was lost to follow-up. Conclusion Preventive transposition of anterior tibial myofascial flaps is a safe,simple and effective management for the treatment of tibial fractures with delayed skin nec-rosis and avoidance of related complications.%目的:探讨预防性胫骨前肌-筋膜瓣转位在胫骨骨折合并重度皮肤软组织损伤发生延迟坏死病例中应用的临床疗效。方法对14例合并重度皮肤软组织损伤的胫骨骨折患者行Ⅰ期骨折固定联合预防性胫前肌-筋膜瓣转位术,发生皮肤延迟坏死后予以植皮,观察其伤口愈合情况、随访骨折愈合及并发症情况。结果14例患者伤口均愈合,无感染并发症,随访13例,骨折均愈合,无骨外露、骨髓炎等并发症,1例失访。结论预防性胫前肌-筋膜瓣转位是一种安全、简便、有效的治疗并发延迟皮肤坏死的胫骨骨折的措施。

  5. On stabilization for a class of nonlinear stochastic time-delay systems: a matrix inequality approach

    Institute of Scientific and Technical Information of China (English)

    Weihai ZHANG; Xuezhen LIU; Shulan KONG; Qinghua LI

    2006-01-01

    This paper treats the feedback stabilization of nonlinear stochastic time-delay systems with state and control-dependent noise. Some locally (globally) robustly stabilizable conditions are given in terms of matrix inequalities that are independent of the delay size. When it is applied to linear stochastic time-delay systems, sufficient conditions for the state-feedback stabilization are presented via linear matrix inequalities. Several previous results are extended to more general systems with both state and control-dependent noise, and easy computation algorithms are also given.

  6. Design and construction of an airfoil with controlled flap

    Science.gov (United States)

    Amin, Md. Ruhul; Rahman, S. M. Mahbobur; Mashud, Mohammad; Rabbi, Md. Fazle

    2017-06-01

    For modern aircrafts maneuvering control and reduction of power loss is a matter of great concern in Aerodynamics. Separation of airflow over the wings of aircraft at high angle of attack or at other situations is a hindrance to proper maneuvering control. As flow separation increases drag force on the aircraft, it consumes excess power. For these reasons much effort and research has gone into the design of aerodynamic surfaces which delay flow separation and keep the local flow attached for as long as possible. One of the simple and cost-effective way is to use a hinged flap on the wing of the aircraft, which lifts and self-adjusts to a position dependent on the aerodynamic forces and flap weight due to reversed flow at increasing angle of attack. There is a limitation of this kind of process. At very high angles of attack, the reversed flow would cause the flap to tip forwards entirely and the effect of the flap would vanish. For recovering this limitation an idea of controlling the movement or rotation of the flap has been proposed in this paper. A light surface was selected as a flap and was coupled to the shaft of a servo motor, which was placed on a model airfoil. For controlling the angle of rotation of the motor as well as the flap arbitrarily, an electronic circuit comprising necessary components was designed and applied to the servo motor successfully.

  7. A delayed presentation of ameloblastic fibrosarcoma in an African patient.

    Science.gov (United States)

    Chauke, Nkhensani Yvonne; Sofianos, Chrysis; Liakos, Dimitri; Ndobe, Elias

    2017-08-01

    A 24-year-old womanpresented with ameloblastic fibrosarcoma arising from ameloblastic fibroma. The delayed presentation accounted for the extensive destruction of the mandible and complete occlusion of her oral cavity. This resulted in an inability to eat and maintain oral hygiene. A multidisciplinary team management approach involved nutritional optimisation, segmental mandibulectomy, reconstruction with a reconstructive plate and a free anterolateral thigh flap to line the the floor of mouth. Functional and aesthetic outcome was acceptable, and the patient is planned for secondary free fibular flap bony reconstruction. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  8. Robust Stability and Stabilization for Singular Time-Delay Systems with Linear Fractional Uncertainties: A Strict LMI Approach

    Directory of Open Access Journals (Sweden)

    Jinxing Lin

    2013-01-01

    Full Text Available This paper is concerned with the problems of delay-dependent robust stability and stabilization for a class of continuous singular systems with time-varying delay in range and parametric uncertainties. The parametric uncertainties are assumed to be of a linear fractional form, which includes the norm bounded uncertainty as a special case and can describe a class of rational nonlinearities. In terms of strict linear matrix inequalities (LMIs, delay-range-dependent robust stability criteria for the unforced system are presented. Moreover, a strict LMI design approach is developed such that, when the LMI is feasible, a desired state feedback stabilizing controller can be constructed, which guarantees that, for all admissible uncertainties, the closed-loop dynamics will be regular, impulse free, and robustly asymptotically stable. Numerical examples are provided to demonstrate the effectiveness of the proposed methods.

  9. Spontaneous Flapping Flight

    Science.gov (United States)

    Vandenberghe, Nicolas; Zhang, Jun; Childress, Stephen

    2004-11-01

    As shown in an earlier work [Vandenberghe, et. al. JFM, Vol 506, 147, 2004], a vertically flapping wing can spontaneously move horizontally as a result of symmetry breaking. In the current experimental study, we investigate the dependence of resultant velocity on flapping amplitude. We also describe the forward thrust generation and how the system dynamically selects a Strouhal number by balancing fluid and body forces. We further compare our model system with examples of biological locomotion, such as bird flight and fish swimming.

  10. Deflection of Light and Shapiro Delay: An Equivalent Medium Theory Approach

    CERN Document Server

    Khorasani, Sina Ataollah

    2012-01-01

    We discuss the deflection of light and Shapiro delay under the influence of gravity as described by Schwarzschild metric. We obtain an exact expression based on the coordinate velocity, as first set forth by Einstein, and present a discussion on the effect of velocity anisotropy. We conclude that the anisotropy in the coordinate velocity, as the velocity apparent to a distant observer, gives rise to a third order error in the deflection angle, so that the practical astronomical observations from gravitational lensing data remain inconclusive on the anisotropy. However, measurement of Shapiro delay provides a fairly convenient way to determine whether the spacetime is optically anisotropic for a distant observer or not. We calculate the Shapiro delay for a round trip path between Earth and Venus and observe excellent agreement to two experimentally reported values measured during a time span of six months in 1967, without any need to extra fitting parameters. This is while the expected delay obtained from an i...

  11. Risk factors of delay proportional probability in diphtheria-tetanus-pertussis vaccination of Iranian children; Life table approach analysis

    Directory of Open Access Journals (Sweden)

    Mohsen Mokhtari

    2015-01-01

    Full Text Available Despite success in expanded program immunization for an increase in vaccination coverage in the children of world, timeliness and schedule of vaccination remains as one of the challenges in public health. This study purposed to demonstrate the related factors of delayed diphtheria-tetanus-pertussis (DTP vaccination using life table approach. A historical cohort study conducted in the poor areas of five large Iran cities. Totally, 3610 children with 24-47 months old age who had documented vaccination card were enrolled. Time of vaccination for the third dose of DTP vaccine was calculated. Life table survival was used to calculate the proportional probability of vaccination in each time. Wilcoxon test was used for the comparison proportional probability of delayed vaccination based on studies factors. The overall median delayed time for DTP3 was 38.52 days. The Wilcoxon test showed that city, nationality, education level of parents, birth order and being in rural areas are related to the high probability of delay time for DTP3 vaccination (P 0.05. Being away from the capital, a high concentration of immigrants in the city borders with a low socioeconomic class leads to prolonged delay in DTP vaccination time. Special attention to these areas is needed to increase the levels of parental knowledge and to facilitate access to the health services care.

  12. A matrix transformation approach to H∞ control via static output feedback for input delay systems

    OpenAIRE

    Du, B; Shu, Z; Lam, J.

    2009-01-01

    This paper addresses the static output feedback (SOF) H∞ control for continuous-time linear systems with an unknown input delay from a novel perspective. New equivalent characterizations on the stability and H∞ performance of the closed-loop system are established in terms of nonlinear matrix inequalities with free parametrization matrices. These delay-dependent characterizations possess a special monotonic structure, which leads to linearized iterative computation. The effectiveness and meri...

  13. An improved impulsive control approach to nonlinear systems with time-varying delays

    Institute of Scientific and Technical Information of China (English)

    Zhang Hua-Guang; Fu Jie; Ma Tie-Dong; Tong Shao-Cheng

    2009-01-01

    A scheme for the impulsive control of nonlinear systems with time-varying delays is investigated in this paper. Based on the Lyapunov-like stability theorem for impulsive functional differential equations (FDEs), some sufficient conditions are presented to guarantee the uniform asymptotic stability of impulsively controlled nonlinear systems with time-varying delays. These conditions are more effective and less conservative than those obtained. Finally, two numerical examples are provided to demonstrate the effectiveness of the proposed method.

  14. The Transverse Musculocutaneous Gracilis Free Flap: Virtual Animation-Assisted Dissection and Application in Breast Reconstruction.

    Science.gov (United States)

    Gabert, Pierre-Elliott; Bodin, Frederic; Aljudaibi, Nawaf; Duquennoy-Martinot, Veronique; Guerreschi, Pierre

    2016-05-01

    The transverse musculocutaneous gracilis free flap is a valuable choice for autologous tissue, unilateral or bilateral breast reconstruction. This procedure is an excellent and customized option for immediate or delayed breast reconstruction in patients with small to moderate size breasts. Few descriptions of flap dissection and breast mound shaping are available. In this first educational video, the authors report the original dissection of the transverse musculocutaneous gracilis free flap used for breast reconstruction. Virtual animations insist on surgical key points and relevant details of the harvesting of the flap.

  15. Variable Structure Disturbance Rejection Control for Nonlinear Uncertain Systems with State and Control Delays via Optimal Sliding Mode Surface Approach

    Directory of Open Access Journals (Sweden)

    Jing Lei

    2013-01-01

    Full Text Available The paper considers the problem of variable structure control for nonlinear systems with uncertainty and time delays under persistent disturbance by using the optimal sliding mode surface approach. Through functional transformation, the original time-delay system is transformed into a delay-free one. The approximating sequence method is applied to solve the nonlinear optimal sliding mode surface problem which is reduced to a linear two-point boundary value problem of approximating sequences. The optimal sliding mode surface is obtained from the convergent solutions by solving a Riccati equation, a Sylvester equation, and the state and adjoint vector differential equations of approximating sequences. Then, the variable structure disturbance rejection control is presented by adopting an exponential trending law, where the state and control memory terms are designed to compensate the state and control delays, a feedforward control term is designed to reject the disturbance, and an adjoint compensator is designed to compensate the effects generated by the nonlinearity and the uncertainty. Furthermore, an observer is constructed to make the feedforward term physically realizable, and thus the dynamical observer-based dynamical variable structure disturbance rejection control law is produced. Finally, simulations are demonstrated to verify the effectiveness of the presented controller and the simplicity of the proposed approach.

  16. To flap or not to flap: a discussion between a fish and a jellyfish

    Science.gov (United States)

    Martin, Nathan; Roh, Chris; Idrees, Suhail; Gharib, Morteza

    2016-11-01

    Fish and jellyfish are known to swim by flapping and by periodically contracting respectively, but which is the more effective propulsion mechanism? In an attempt to answer this question, an experimental comparison is made between simplified versions of these motions to determine which generates the greatest thrust for the least power. The flapping motion is approximated by pitching plates while periodic contractions are approximated by clapping plates. A machine is constructed to operate in either a flapping or a clapping mode between Reynolds numbers 1,880 and 11,260 based on the average plate tip velocity and span. The effect of the total sweep angle, total sweep time, plate flexibility, and duty cycle are investigated. The average thrust generated and power required per cycle are compared between the two modes when their total sweep angle and total sweep time are identical. In general, operating in the clapping mode required significantly more power to generate a similar thrust compared to the flapping mode. However, modifying the duty cycle for clapping caused the effectiveness to approach that of flapping with an unmodified duty cycle. These results suggest that flapping is the more effective propulsion mechanism within the range of Reynolds numbers tested. This work was supported by the Charyk Bio-inspired Laboratory at the California Institute of Technology, the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469, and the Summer Undergraduate Research Fellowships program.

  17. Quadrilobed superior gluteal artery perforator flap for sacrococcygeal defects

    Institute of Scientific and Technical Information of China (English)

    HAI Heng-lin; SHEN Chuan-an; CHAI Jia-ke; LI Hua-tao; YU Yong-ming; LI Da-wei

    2013-01-01

    paraplegia,the range of motion of the hip joints was not affected.Conclusion The use of the quadrilobed superior gluteal artery perforator flap can overcome the disadvantages of traditional perforator flaps and represents an improved approach for repairing soft tissue defects in the sacrococcygeal region.

  18. Adipofascial Anterolateral Thigh Flap Safety: Applications and Complications

    Directory of Open Access Journals (Sweden)

    Tommaso Agostini

    2013-03-01

    Full Text Available Background A thinned anterolateral thigh (ALT flap is often harvested to achieve optimalskin resurfacing. Several techniques have been described to thin an ALT flap including anadipocutaneous flap, an adipofascial flap and delayed debulking.Methods By systematically reviewing all of the available literature in English and French, thepresent manuscript attempts to identify the common surgical indications, complications anddonor site morbidity of the adipofascial variant of the ALT flap. The studies were identifiedby performing a systematic search on Medline, Ovid, EMBASE, the Cochrane Database ofSystematic Reviews, Current Contents, PubMed, Google, and Google Scholar.Results The study selection process was adapted from the Preferred Reporting Items forSystematic Reviews and Meta-Analyses statement, and 15 articles were identified usingthe study inclusion criteria. These articles were then reviewed for author name(s, year ofpublication, flap dimensions and thickness following defatting, perforator type, type of transfer,complications, thinning technique, number of cases with a particular area of application anddonor site morbidity.Conclusions The adipofascial variant of the ALT flap provides tissue to fill large defects andimprove pliability. Its strong and safe blood supply permits adequate immediate or delayeddebulking without vascular complications. The presence of the deep fascia makes it possibleto prevent sagging by suspending and fixing the flap for functional reconstructive purposes(e.g., the intraoral cavity. Donor site morbidity is minimal, and thigh deformities can bereduced through immediate direct closure or liposuction and direct closure. A safe bloodsupply was confirmed by the rate of secondary flap debulking.

  19. Projects Delay Factors of Saudi Arabia Construction Industry Using PLS-SEM Path Modelling Approach

    Directory of Open Access Journals (Sweden)

    Abdul RahmanIsmail

    2016-01-01

    Full Text Available This paper presents the development of PLS-SEM Path Model of delay factors of Saudi Arabia construction industry focussing on Mecca City. The model was developed and assessed using SmartPLS v3.0 software and it consists of 37 factors/manifests in 7 groups/independent variables and one dependent variable which is delay of the construction projects. The model was rigorously assessed at measurement and structural components and the outcomes found that the model has achieved the required threshold values. At structural level of the model, among the seven groups, the client and consultant group has the highest impact on construction delay with path coefficient β-value of 0.452 and the project management and contract administration group is having the least impact to the construction delay with β-value of 0.016. The overall model has moderate explaining power ability with R2 value of 0.197 for Saudi Arabia construction industry representation. This model will able to assist practitioners in Mecca city to pay more attention in risk analysis for potential construction delay.

  20. 背阔肌肌皮瓣联合假体在乳腺癌术后二期乳房再造中的应用%Application of Latissimus Dorsi Myocutaneous Flap with Breast Implant in Delayed Breast Reconstruction after Mastectomy

    Institute of Scientific and Technical Information of China (English)

    郑厚兵; 单秀英; 陈祥锦; 张惠灏; 朱有志; 王美水; 王彪

    2015-01-01

    目的:探讨背阔肌肌皮瓣联合假体植入在乳腺癌术后二期乳房再造术中的临床应用。方法2009年至2013年,共8例乳腺癌术后年轻患者接受二期乳房再造手术。术前以排水法测定健侧乳房体积,根据患者健侧乳房形状、大小及背部组织情况,设计胸背部供区皮瓣,术中测量移植皮瓣的容积,然后根据健侧乳房和移植皮瓣的容积差,选择大小合适的乳房假体,将假体埋植于背阔肌-胸大肌后间隙,利用背阔肌肌皮瓣移植联合乳房硅胶假体进行二期乳房再造。结果本组患者术后随访6个月至4年,再造乳房外形较佳,效果满意,供区无明显并发症。结论对于年轻有生育要求的乳腺癌术后乳房缺失患者,健侧乳房较大,利用背阔肌肌皮瓣联合假体进行乳房再造,可取得良好的手术效果。%Objective To explore the application of latissimus dorsi myocutneous flap and breast implant in delayed breast reconstruction surgery after mastectomy. Methods From 2009 to 2013, 8 cases received delayed breast reconstruction operation after mastectomy. The breast volumetry measurement technique was used to determine the mass of the breast preoperatively, then the donor flap was designed at the chest-back region according to the condition of the dorsal skin and the shape of the contralateral breast. The mass of graft flap was measured intraoperatively, then the suitable implant was selected based on the difference between the volume of the contralateral breast and the graft flap. The breast implant was then placed in the interspace between the latissimus dorsi muscle and the pectoralis major muscle to reconstruct the breast (secondary phase). Results All patients were followed up for 6 months to 4 years. The overall appearance of the constructed breast were satisfactory, no significant complications were observed in the donor region. Conclusion For young patients of breast cancer with

  1. Graft placement with an omental flap for ruptured infective common iliac aneurysm in a patient with a continuous flow left ventricular assist device: alternative surgical approach avoiding driveline injury and pathogen identification by 16S ribosomal DNA gene analysis.

    Science.gov (United States)

    Akiyama, Masatoshi; Hayatsu, Yukihiro; Sakatsume, Ko; Fujiwara, Hidenori; Shimizu, Takuya; Akamatsu, Daijirou; Kakuta, Risako; Gu, Yoshiaki; Kaku, Mitsuo; Kumagai, Kiichiro; Kawamoto, Shunsuke; Goto, Hitoshi; Ohuchi, Noriaki; Saiki, Yoshikatsu

    2016-12-01

    Patients supported by mechanical circulatory support have to wait for longer periods for heart transplantation in Japan. Infective events are a major complication and influence survival. Here, we present the case of a patient with an implantable left ventricular assist device for 6 months who had the complication of ruptured infective common iliac aneurysm. Graft placement with an omental flap was successfully performed via the alternative surgical approach to avoid percutaneous driveline injury. In samples of aortic specimens, 16S ribosomal DNA gene analysis identified Helicobacter cinaedi. Complete removal of the infected tissue and correct pathogen identification may have been relevant to the good clinical course.

  2. Partial breast reconstruction with mini superficial inferior epigastric artery and mini deep inferior epigastric perforator flaps.

    Science.gov (United States)

    Spiegel, Aldona J; Eldor, Liron

    2010-08-01

    In this study, partial breast reconstruction was undertaken after breast conservation therapy using mini abdominal free flaps on both an immediate and delayed basis.Patient demographics, oncologic status, reconstructive data, and complications were collected from medical records.Twelve patients (age range 39-60) were included in this study with a mean follow-up time of 5 years. Ten mini superficial inferior epigastric artery flaps and 2 mini deep inferior epigastric perforator flaps were used (7 immediate and 5 delayed reconstructions). No flap lost, 1 minor abdominal wound dehiscence, and no local or distant recurrences were noted. Good to excellent results were reported by 91% of the women.In properly selected patients with high motivation toward breast conservation, tailored abdominal mini-free flaps can safely and satisfactorily be implemented for the reconstruction of partial mastectomy defects. Patients should be comprehensively educated on the potential future implications of using the abdominal donor site for partial breast reconstruction.

  3. Active Flap Control of the SMART Rotor for Vibration Reduction

    Science.gov (United States)

    Hall, Steven R.; Anand, R. Vaidyanathan; Straub, Friedrich K.; Lau, Benton H.

    2009-01-01

    Active control methodologies were applied to a full-scale active flap rotor obtained during a joint Boeing/ DARPA/NASA/Army test in the Air Force National Full-Scale Aerodynamic Complex 40- by 80-foot anechoic wind tunnel. The active flap rotor is a full-scale MD 900 helicopter main rotor with each of its five blades modified to include an on-blade piezoelectric actuator-driven flap with a span of 18% of radius, 25% of chord, and located at 83% radius. Vibration control demonstrated the potential of active flaps for effective control of vibratory loads, especially normal force loads. Active control of normal force vibratory loads using active flaps and a continuous-time higher harmonic control algorithm was very effective, reducing harmonic (1-5P) normal force vibratory loads by 95% in both cruise and approach conditions. Control of vibratory roll and pitch moments was also demonstrated, although moment control was less effective than normal force control. Finally, active control was used to precisely control blade flap position for correlation with pretest predictions of rotor aeroacoustics. Flap displacements were commanded to follow specific harmonic profiles of 2 deg or more in amplitude, and the flap deflection errors obtained were less than 0.2 deg r.m.s.

  4. The use of free flaps in skull base reconstruction.

    Science.gov (United States)

    Macía, G; Picón, M; Nuñez, J; Almeida, F; Alvarez, I; Acero, J

    2016-02-01

    Skull base tumours are rare, comprising less than 1% of all tumours of the head and neck. Surgical treatment of these tumours involves the approach, the resection, and the reconstruction of the defect, which present a challenge due to the technical difficulty and anatomical complexity. A retrospective study of 17 patients with tumours involving the skull base, treated by resection and immediate reconstruction using microsurgical free flaps, is presented; 11 were men and six were women. The following types of flap were used: osteocutaneous fibula flaps, fasciocutaneous anterolateral thigh flaps, and myocutaneous latissimus dorsi flaps. The most common histology of the tumours was squamous cell carcinoma. The most frequent point of origin was the paranasal sinuses (58.8%). All of the free flaps used for reconstruction were viable. A cerebrospinal fluid fistula occurred in two patients, and in one of these cases, meningoencephalitis led to death. In conclusion, the reconstruction of large defects of the skull base after ablation requires a viable tissue that in many cases can be obtained only through the use of microvascular free flaps. The type of flap to be selected depends on the anatomical structures and size of the defect to be restored.

  5. Generalized projective synchronization in time-delayed systems: nonlinear observer approach.

    Science.gov (United States)

    Ghosh, Dibakar

    2009-03-01

    In this paper, we consider the projective-anticipating, projective, and projective-lag synchronization in a unified coupled time-delay system via nonlinear observer design. A new sufficient condition for generalized projective synchronization is derived analytically with the help of Krasovskii-Lyapunov theory for constant and variable time-delay systems. The analytical treatment can give stable synchronization (anticipatory and lag) for a large class of time-delayed systems in which the response system's trajectory is forced to have an amplitude proportional to the drive system. The constant of proportionality is determined by the control law, not by the initial conditions. The proposed technique has been applied to synchronize Ikeda and prototype models by numerical simulation.

  6. Deep inferior epigastric perforator flap for breast reconstruction: experience with 43 flaps

    Institute of Scientific and Technical Information of China (English)

    YAN Xiao-qing; YANG Hong-yan; ZHAO Yu-ming; YOU Lei; XU Jun

    2007-01-01

    Background In the past decade, there has been increasing breast reconstructions after mastectomy. The ideal material for reconstruction of a breast is fat and skin. The transverse rectus abdominis myocutaneous (TRAM) flap has been the gold standard for breast reconstruction until recently. Abdominal wall function is a major concern for plastic surgeons in breast reconstruction with TRAM flaps. The deep inferior epigastric perforator (DIEP) free flap spares the whole rectus abdominis muscle, includes skin and fat only, and therefore preserves adequate abdominal wall competence. The aim of this study was to summarize our experience in breast reconstruction with DIEP flap.Methods Between March 2000 and August 2005, a total of 43 breast reconstructions were performed on 40 patients by our surgeons using DIEP flap (3 patients had bilateral procedures), 14 of them were immediate surgeries and 26 were delayed. Abdominal function, satisfaction with the donor site and reconstructed breast, and the sensation recovery was assessed respectively during follow-up.Results The mean age of the patients was 38.6 years (range, 28-50). The size of the flaps was 11 cm×26 cm in average (height 10-12 cm, width 15-33 cm). The mean length of the vascular pedicles was 9.3 cm (range, 7-12). The patients were followed up for a mean of 16 months (range, 6-30 months). During the follow-up, 2 (5%) patients had total flap loss, 2 (5%) had partial necrosis, 4 (9%) had wound edge necrosis in the abdomen, and 1 had axillary seroma. None of the patients had hernia, and all of them were able to resume their daily activities after the operation. Patient satisfaction with the reconstructed breast rated high, 95% of the patients achieved spontaneous return of sensation in the reconstructed breast, but none of them had a sensation equivalent or approximate to the normal.Conclusions The DIEP flap has the same benefits as the TRAM flap without destroying the continuity of the rectus muscle. It can reduce

  7. A new flap design for release of parallel contracture bands: dual opposing five-flap z-plasty.

    Science.gov (United States)

    Ersoy, Burak

    2014-12-01

    Skin contractures secondary to burn and other types of trauma can be encountered on almost every part of human body, best addressed by a custom treatment protocol tailored for each patient. Skin graft, local flap as well as distant flap options are available, each with intrinsic advantages and disadvantages. In the presence of weblike contracture the utilization of local tissue, when available, is a prefered approach for a relatively better appearance through a reasonably simpler surgical intervention, compared to skin graft applications and distant flap options. Among many other techniques and modalities utilized for this purpose, the dual opposing five-flap z-plasty method which is a novel method designed as a modification of the paired five-flap z-plasty technique promises to be a useful treatment option for the release of parallel contracture bands with satisfactory results in selected patients. Copyright © 2014 Elsevier Ltd and ISBI. All rights reserved.

  8. Flap prefabrication and stem cell-assisted tissue expansion: how we acquire a monoblock flap for full face resurfacing.

    Science.gov (United States)

    Li, Qingfeng; Zan, Tao; Li, Haizhou; Zhou, Shuangbai; Gu, Bin; Liu, Kai; Xie, Feng; Xie, Yun

    2014-01-01

    Total face skin and soft-tissue defects remain one of the biggest challenges in reconstructive surgery. Reconstruction of the entire face with uniform coverage and delicate features is difficult to achieve. To avoid the patchwork result seen in multiple flaps and skin grafts, 1 monoblock flap that has similar color, texture, and thickness might be an ideal option to minimize the incisional scars and several surgical procedures but is unavailable with current approaches because of the lack of sufficient matched tissue and the unreliable blood supply for such a large flap. To acquire a monoblock flap for full face reconstruction, we combine the prefabricated flaps, skin overexpansion, and bone marrow mononuclear stem cell transplantation for total facial resurfacing. In this article, we present our experience from our case series that provides universally matched skin and near-normal facial contour. It is a reliable and an excellent reconstructive option for massive facial skin defect.

  9. Assessing the suitability of medial sural artery perforator flaps in tongue reconstruction – An outcome study

    Science.gov (United States)

    Kwon, Soo-Ha; Tsai, Chia-Hsuan; Chang, Kai-Ping; Kao, Huang-Kai

    2017-01-01

    Introduction Oncological resection of the tongue can be reconstructed using a multitude of free flaps. The medial sural artery perforator (MSAP) flap has been well described in the literature in terms of its anatomy and harvest. However, functional outcome studies of post-reconstruction tongue defects using the MSAP flap have not been reported. This study represents the largest outcome study of patients with tongue reconstructions using MSAP flaps and a comprehensive review of its use. Materials and methods From December of 2010 to October of 2015, 579 patients with subtotal glossectomy and free flap reconstructions in Chang Gung Memorial Hospital were retrospectively reviewed. 27 patients were reconstructed with MSAP flap. The pre- and intra-operative factors, as well as flap-related factors were analyzed. Post-operative complications and functional outcomes were evaluated. Donor site assessment were also conducted. Results A 96.3% flap survival rate was found with an average total operating time of 6 hours and 18 minutes. 84.6% of patients had primary closure of the donor site with and the remaining either had skin grafts or delayed closure. Donor site closure can be achieved primarily with no functional deficit. Speech intelligibility remained for most patients. 100% of patients resumed normal oral feeding. Conclusion The MSAP flap is a small to medium sized flap most suited for subtotal glossectomy defects where optimal outcomes can be achieved in terms of speech clarity and restoration of oral intake. PMID:28182639

  10. Quasipolynomial Approach to Simultaneous Robust Control of Time-Delay Systems

    Directory of Open Access Journals (Sweden)

    Nikolaj Semenič

    2014-01-01

    Full Text Available A control law for retarded time-delay systems is considered, concerning infinite closed-loop spectrum assignment. An algebraic method for spectrum assignment is presented with a unique optimization algorithm for minimization of spectral abscissa and effective shaping of the chains of infinitely many closed-loop poles. Uncertainty of plant delays of a certain structure is considered in a sense of a robust simultaneous stabilization. Robust performance is achieved using mixed sensitivity design, which is incorporated into the addressed control law.

  11. Improved system blind identification based on second-order cyclostationary statistics: A group delay approach

    Indian Academy of Sciences (India)

    P V S Giridhar; S V Narasimhan

    2000-04-01

    An improved system blind identification method based on second-order cyclostationary statistics and the properties of group delay, has been proposed. This is achieved by applying a correction to the estimated phase (by the spectral correlation density of the system output) for the poles, in the group delay domain. The results indicate a significant improvement in system blind identification, in terms of root mean square error. Depending upon the signal-to-noise ratio, the improvement in percentage normalized mean square error ranges between 20 and 50%.

  12. Central incisor loss after delayed replantation following avulsion: a contemporary restorative and adjunctive orthodontic management approach.

    Science.gov (United States)

    Savi, Andrea; Turillazzi, Oliviero; Cocconi, Renato; Bonanini, Mauro; Pizzi, Silvia; Manfredi, Maddalena

    2012-04-01

    Delayed replantation of an avulsed tooth may result in rapid root resorption or, more frequently, dental ankylosis with subsequent bone substitution. If this process develop slowly, it is possible to observe that tooth loss is characterized by a well conserved alveolus with regard to bone preservation, particularly in vertical dimension. This clinical case reports a dental trauma of a central incisor in a young boy characterized by tooth avulsion and its delayed replantation. After 10 years, dental ankylosis of the incisor was recorded and the patient underwent a prosthetic-orthodontic rehabilitation using CAD-CAM technology and no-prep veneers.

  13. Breast Reconstruction with Flap Surgery

    Science.gov (United States)

    Breast reconstruction with flap surgery Overview By Mayo Clinic Staff Breast reconstruction is a surgical procedure that restores shape to ... breast tissue to treat or prevent breast cancer. Breast reconstruction with flap surgery is a type of breast ...

  14. Unified stabilizing controller synthesis approach for discrete-time intelligent systems with time delays by dynamic output feedback

    Institute of Scientific and Technical Information of China (English)

    LIU MeiQin

    2007-01-01

    A novel model, termed the standard neural network model (SNNM), is advanced to describe some delayed (or non-delayed) discrete-time intelligent systems composed of neural networks and Takagi and Sugeno (T-S) fuzzy models. The SNNM is composed of a discrete-time linear dynamic system and a bounded static nonlinear operator. Based on the global asymptotic stability analysis of the SNNMs, linear and nonlinear dynamic output feedback controllers are designed for the SNNMs to stabilize the closed-loop systems, respectively. The control design equations are shown to be a set of linear matrix inequalities (LMIs) which can be easily solved by various convex optimization algorithms to determine the control signals. Most neural-network-based (or fuzzy) discrete-time intelligent systems with time delays or without time delays can be transformed into the SNNMs for controller synthesis in a unified way. Three application examples show that the SNNMs not only make controller synthesis of neural-network-based (or fuzzy) discrete-time intelligent systems much easier, but also provide a new approach to the synthesis of the controllers for the other type of nonlinear systems.

  15. Delayed four-wave-mixing spectroscopy in molecular crystals : A nonperturbative approach

    NARCIS (Netherlands)

    Weitekamp, D.P.; Duppen, Koos; Wiersma, Douwe A.

    1983-01-01

    The delayed or time-domain four-wave-mixing experiment is treated in the regime of intense near-resonant pulses. The interaction with the radiation during both pump and probe pulses is considered to all powers of the electric field amplitude. Analytical results are obtained for an effective four-lev

  16. Stability of quantized time-delay nonlinear systems : a Lyapunov–Krasowskii-functional approach

    NARCIS (Netherlands)

    Persis, Claudio De; Mazenc, Frédéric

    2010-01-01

    Lyapunov–Krasowskii functionals are used to design quantized control laws for nonlinear continuous-time systems in the presence of constant delays in the input. The quantized control law is implemented via hysteresis to avoid chattering. Under appropriate conditions, our analysis applies to stabiliz

  17. AN APPROACH TO DESIGN OBSERVER FOR A CLASS OF DISCRETE CONTROL SYSTEMS WITH TIME-DELAY

    Institute of Scientific and Technical Information of China (English)

    Xue Liu; Cunchen Gao

    2009-01-01

    The design of functional observer for a class of discrete systems with time-delay is concerned. The solution to Sylvester function is given. An improved method for the functional observer design is proposed by the condition of linear matrix inequality. In the end, an example is given to illustrate the feasibility of the method.

  18. Delayed four-wave-mixing spectroscopy in molecular crystals : A nonperturbative approach

    NARCIS (Netherlands)

    Weitekamp, D.P.; Duppen, Koos; Wiersma, Douwe A.

    1983-01-01

    The delayed or time-domain four-wave-mixing experiment is treated in the regime of intense near-resonant pulses. The interaction with the radiation during both pump and probe pulses is considered to all powers of the electric field amplitude. Analytical results are obtained for an effective four-lev

  19. Using a Multiobjective Approach to Balance Mission and Network Goals within a Delay Tolerant Network Topology

    Science.gov (United States)

    2009-03-01

    Proceedings of the 2006 SIGCOMM workshop on Challenged networks. New York, NY, USA: ACM. 23. Cerf, Vincent , RFC 4838 Delay-Tolerant Networking...IEEE Journal of Robotics and Automation, 1986. 2(1): p. 14-23. 44. Burns, Brendan., Oliver Brock, and Brian Neil Levine. MORA routing and capacity

  20. Stability of quantized time-delay nonlinear systems : A Lyapunov-Krasowskii-functional approach

    NARCIS (Netherlands)

    Persis, Claudio De; Mazenc, Frédéric

    2009-01-01

    Lyapunov-Krasowskii functionals are used to design quantized control laws for nonlinear continuous-time systems in the presence of time-invariant constant delays in the input. The quantized control law is implemented via hysteresis to avoid chattering. Under appropriate conditions, our analysis appl

  1. Robust Stability and H∞ Stabilization of Switched Systems with Time-Varying Delays Using Delta Operator Approach

    Directory of Open Access Journals (Sweden)

    Chen Qin

    2013-01-01

    Full Text Available This paper considers the problems of the robust stability and robust H∞ controller design for time-varying delay switched systems using delta operator approach. Based on the average dwell time approach and delta operator theory, a sufficient condition of the robust exponential stability is presented by choosing an appropriate Lyapunov-Krasovskii functional candidate. Then, a state feedback controller is designed such that the resulting closed-loop system is exponentially stable with a guaranteed H∞ performance. The obtained results are formulated in the form of linear matrix inequalities (LMIs. Finally, a numerical example is provided to explicitly illustrate the feasibility and effectiveness of the proposed method.

  2. Reconstructive options in patients with late complications after surgery and radiotherapy for head and neck cancer: remember the deltopectoral flap.

    Science.gov (United States)

    Krijgh, David D; Mureau, Marc A M

    2013-08-01

    During the past 40 years, free vascularized flaps have become the golden standard in the reconstruction of postoncologic head and neck defects. When there is a need for an osteofasciocutaneous free flap, the free fibula flap is the first choice because of the advantages of its long bone structure, high reliability, and minimal donor-site morbidity. However, most of these patients receive adjuvant radiation therapy, which sometimes causes symptomatic fibrosis, contractures, and (osteo)radionecrosis. In case of these late complications, locoregional reconstructive options are often limited, and complex secondary free flap procedures are not always feasible or preferred by the patient. The present paper discusses regional and free flap reconstructive options and demonstrates with 3 cases that the delayed deltopectoral flap remains a very safe, reliable, and easy flap, which still has a place in the management of these complex reconstructive challenges.

  3. New Approaches For Asteroid Spin State and Shape Modeling From Delay-Doppler Radar Images

    Science.gov (United States)

    Raissi, Chedy; Lamee, Mehdi; Mosiane, Olorato; Vassallo, Corinne; Busch, Michael W.; Greenberg, Adam; Benner, Lance A. M.; Naidu, Shantanu P.; Duong, Nicholas

    2016-10-01

    Delay-Doppler radar imaging is a powerful technique to characterize the trajectories, shapes, and spin states of near-Earth asteroids; and has yielded detailed models of dozens of objects. Reconstructing objects' shapes and spins from delay-Doppler data is a computationally intensive inversion problem. Since the 1990s, delay-Doppler data has been analyzed using the SHAPE software. SHAPE performs sequential single-parameter fitting, and requires considerable computer runtime and human intervention (Hudson 1993, Magri et al. 2007). Recently, multiple-parameter fitting algorithms have been shown to more efficiently invert delay-Doppler datasets (Greenberg & Margot 2015) - decreasing runtime while improving accuracy. However, extensive human oversight of the shape modeling process is still required. We have explored two new techniques to better automate delay-Doppler shape modeling: Bayesian optimization and a machine-learning neural network.One of the most time-intensive steps of the shape modeling process is to perform a grid search to constrain the target's spin state. We have implemented a Bayesian optimization routine that uses SHAPE to autonomously search the space of spin-state parameters. To test the efficacy of this technique, we compared it to results with human-guided SHAPE for asteroids 1992 UY4, 2000 RS11, and 2008 EV5. Bayesian optimization yielded similar spin state constraints within a factor of 3 less computer runtime.The shape modeling process could be further accelerated using a deep neural network to replace iterative fitting. We have implemented a neural network with a variational autoencoder (VAE), using a subset of known asteroid shapes and a large set of synthetic radar images as inputs to train the network. Conditioning the VAE in this manner allows the user to give the network a set of radar images and get a 3D shape model as an output. Additional development will be required to train a network to reliably render shapes from delay

  4. Delayed Open Reduction and K-Wire Fixation of Widely Displaced Supracondylar Fractures of Humerus in Children using Medial Approach

    Science.gov (United States)

    Waikhom, Sanjib; Ibomcha, Irom; Digendra, Akoijam; Sohkhlet, Handboy R

    2016-01-01

    Introduction Supracondylar fractures of humerus in children are usually treated with percutaneous pinning on emergency basis. When the operating time is delayed, percutaneous pinning is difficult due to massive swelling. Late presentation is common in developing countries. Aim To assess the outcome of open reduction and internal fixation with K-wire of widely displaced supracondylar fracture when operated later than 2 days after the injury. Materials and Methods A total of 52 children (aged 3-12 years) with widely displaced supracondylar fracture of humerus (Gartland type-III) who presented later than 2 days after injury were treated with open reduction through medial approach and fixation with cross K-wires. Results were assessed with Flynn’s criteria. Result: A total of 40 patients completed follow-up. Mean age of all (n=52) patients was 4.8 years (range 3-12 years). Mean delay of presentation was 7.5 days (range 2-14 days). Hundred percent patients had satisfactory results according to Flynn’s criteria. Two patients had pin infections. Conclusion Open reduction through medial approach and fixation with two cross K-wires is a reliable method of treatment for supracondylar fractures of humerus in children when the operation is delayed. PMID:27656516

  5. Networked iterative learning control approach for nonlinear systems with random communication delay

    Science.gov (United States)

    Liu, Jian; Ruan, Xiaoe

    2016-12-01

    This paper constructs a proportional-type networked iterative learning control (NILC) scheme for a class of discrete-time nonlinear systems with the stochastic data communication delay within one operation duration and being subject to Bernoulli-type distribution. In the scheme, the communication delayed data is replaced by successfully captured one at the concurrent sampling moment of the latest iteration. The tracking performance of the addressed NILC algorithm is analysed by statistic technique in virtue of mathematical expectation. The analysis shows that, under certain conditions, the expectation of the tracking error measured in the form of 1-norm is asymptotically convergent to zero. Numerical experiments are carried out to illustrate the validity and effectiveness.

  6. Stability of linear delay differential equations a numerical approach with Matlab

    CERN Document Server

    Breda, Dimitri; Vermiglio, Rossana

    2015-01-01

    This book presents the authors' recent work on the numerical methods for the stability analysis of linear autonomous and periodic delay differential equations, which consist in applying pseudospectral techniques to discretize either the solution operator or the infinitesimal generator and in using the eigenvalues of the resulting matrices to approximate the exact spectra. The purpose of the book is to provide a complete and self-contained treatment, which includes the basic underlying mathematics and numerics, examples from population dynamics and engineering applications, and Matlab programs implementing the proposed numerical methods. A number of proofs is given to furnish a solid foundation, but the emphasis is on the (unifying) idea of the pseudospectral technique for the stability analysis of DDEs. It is aimed at advanced students and researchers in applied mathematics, in dynamical systems and in various fields of science and engineering, concerned with delay systems. A relevant feature of the book is t...

  7. Semigroup Approach to Semilinear Partial Functional Differential Equations with Infinite Delay

    Directory of Open Access Journals (Sweden)

    Hassane Bouzahir

    2007-02-01

    Full Text Available We describe a semigroup of abstract semilinear functional differential equations with infinite delay by the use of the Crandall Liggett theorem. We suppose that the linear part is not necessarily densely defined but satisfies the resolvent estimates of the Hille-Yosida theorem. We clarify the properties of the phase space ensuring equivalence between the equation under investigation and the nonlinear semigroup.

  8. Semigroup Approach to Semilinear Partial Functional Differential Equations with Infinite Delay

    Directory of Open Access Journals (Sweden)

    Bouzahir Hassane

    2007-01-01

    Full Text Available We describe a semigroup of abstract semilinear functional differential equations with infinite delay by the use of the Crandall Liggett theorem. We suppose that the linear part is not necessarily densely defined but satisfies the resolvent estimates of the Hille-Yosida theorem. We clarify the properties of the phase space ensuring equivalence between the equation under investigation and the nonlinear semigroup.

  9. The dynamics of the HIV infection: a time-delay differential equation approach

    CERN Document Server

    Bacelar, Flora S; Santos, Rita M Zorzenon dos

    2010-01-01

    In this work we introduce a differential equation model with time-delay that describes the three-stage dynamics and the two time scales observed in HIV infection. Assuming that the virus has high mutation and rapid reproduction rates that stress the immune system throughout the successive activation of new responses to new undetectable strains, the delay term describes the time interval necessary to mount new specific immune responses. This single term increases the number of possible solutions and changes the phase space dynamics if compared to the model without time delay. We observe very slow transits near the unstable fixed point, corresponding to a healthy state, and long time decay to the stable fixed point that corresponds to the infected state. In contrast to the results obtained for models using regular ODE, which only allow for partial descriptions of the course of the infection, our model describes the entire course of infection observed in infected patients: the primary infection, the latency peri...

  10. Pattern formation in a reaction-advection model with delay: a continuum approach to myxobacterial rippling

    Science.gov (United States)

    Börner, U.; Bär, M.

    2004-07-01

    Standing wave oscillations of the cell density (rippling) are observed in premature aggregates of developing myxobacteria. Recently the underlying pattern formation mechanism was shown to be based on the interplay between active cell motion and local interactions triggering reversals in the cells' direction of motion. The propagation of information through the system is mediated by the internal state of moving cells rather than by diffusible chemical signals. Discrete cellular automata and coupled-map lattices have been investigated earlier and indicate the importance of a minimum refractory period between subsequent reversals of a cell. In this paper we consider the continuum limit of the process, that yields a set of hyperbolic partial differential equations with a a single discrete time delay. The time delay corresponds to the duration of the mentioned refractory period of the cells. According to linear stability analysis a minimal time delay is required for a wave instability to occur. The results of the continuum model are in reasonable agreement with the findings in the discrete models adding credibility to the earlier studies.

  11. A Game-Theoretic Approach to Energy-Efficient Modulation in CDMA Networks with Delay Constraints

    CERN Document Server

    Meshkati, Farhad; Poor, H Vincent; Schwartz, Stuart C

    2007-01-01

    A game-theoretic framework is used to study the effect of constellation size on the energy efficiency of wireless networks for M-QAM modulation. A non-cooperative game is proposed in which each user seeks to choose its transmit power (and possibly transmit symbol rate) as well as the constellation size in order to maximize its own utility while satisfying its delay quality-of-service (QoS) constraint. The utility function used here measures the number of reliable bits transmitted per joule of energy consumed, and is particularly suitable for energy-constrained networks. The best-response strategies and Nash equilibrium solution for the proposed game are derived. It is shown that in order to maximize its utility (in bits per joule), a user must choose the lowest constellation size that can accommodate the user's delay constraint. Using this framework, the tradeoffs among energy efficiency, delay, throughput and constellation size are also studied and quantified. The effect of trellis-coded modulation on energy...

  12. [Thoracodorsal pedicled perforator flap for chest wall and breast reconstruction in children: Illustration with two clinical cases].

    Science.gov (United States)

    Minetti, C; Colson, T; Gisquet, H; Pujo, J; Brix, M; Simon, E

    2014-02-01

    Perforator flaps represent a new approach in reconstructive surgery including the thoracodorsal perforator flap. It can be used as a free or pedicled tissue transfer. By exposing two clinical cases, we demonstrate that this flap is an interesting option for children and adolescents chest wall skin coverage with less morbidity compared to myocutaneous latissimus dorsi flap. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

  13. TRAM flap in reconstructive operations in patients with breast cancer

    Directory of Open Access Journals (Sweden)

    A. D. Zikiryakhodzhaev

    2015-01-01

    Full Text Available The treatment of breast cancer (BC is a relevant problem. Surgery is a key treatment method for BC. The volume of its operations varies from radical mastectomies to lumpectomies and, in the areas of regional metastases, from three-level lymphadenectomy to sentinel lymph node biopsy. Objective: to assess whether a displaced TRAM flap may be used for reconstructive operations for BC. The paper presents some experience in treating 11 BC patients in whom a displaced TRAMP flap was employed for reconstruction. At this time, the displaced TRAM flap was applied for delayed reconstruction in 3 patients. The mean age of the patients was 45.5 ± 15.7 years. In 8 BC patients undergoing one-stage reconstruction with a displaced TRAM flap, the treatment schedule was as follows: surgical treatment in 1 patient, combined treatment in 2 patients, and multimodality treatment in 5. The patients received targeted therapy in 3 cases or hormone therapy in 6. A lower abdominal skin-and-fat flap on one vascular pedicle was used in all the 11 patients.Indications for using a displaced TRAM flap were determined; complications were analyzed. The percentage of complications due to the use of a displaced TRAM flap was 9.1 % in our study.To reduce the rate of complications after breast reconstruction with a displaced TRAM flap, we carefully selected patients for this choiceof a plastic component. The displaced TRAM flap is one of the variants for delayed breast reconstruction despite its duration and complexity. Corrective surgery is further used to achieve breast symmetry. Corrective operations, namely, breast liposuction and submammary fold formation, were performed in 2 patients. For full breast recovery, the nipple-areolar complex is to be formed following skin-sparing mastectomies and delayed breast reconstructions. The cosmetic effect was evaluated in 11 patients as excellent in 4 (36.4 % cases, good in 7 (63.6 %. Neither local recurrences nor distant

  14. The effects of local nitroglycerin on the surgical delay procedure in prefabricated flaps by vascular implant in rats Efeitos da nitroglicerina tópica na autonomização de retalhos pré-fabricados por implante vascular em ratos

    Directory of Open Access Journals (Sweden)

    Jairo Zacchê de Sá

    2012-12-01

    Full Text Available PURPOSE: To evaluate the effect of local nitroglycerin on the viable area of a prefabricated flap for vascular implant in rats, and to investigate the surgical delay procedure. METHODS: A femoral pedicle was implanted under the skin of the abdominal wall in forty Wistar rats. The animals were divided into four groups of ten: group 1 - without surgical delay procedure and local nitroglycerin; group 2 - with surgical delay procedure, but without local nitroglycerin; group 3 - without surgical delay procedure, but with local nitroglycerin; and group 4 - with simultaneous surgical delay procedure and local nitroglycerin. The percentages of the viable areas, in relation to the total flap, were calculated using AutoCAD R 14. RESULTS: The mean percentage value of the viable area was 8.9% in the group 1. 49.4% in the group 2; 8.4% in the group 3 and 1.1% in the group 4. There was significant difference between groups 1 and 2 (p=0.005, 1 and 4 (p=0.024, 2 and 3 (p=0.003, 2 and 4 (p=0.001. These results support the hypothesis that the closure of the arterial venous channels is responsible for the phenomenon of surgical delay procedure. CONCLUSION: Local nitroglycerin did not cause an increase in the prefabricated viable flap area by vascular implantation and decreased the viable flap area that underwent delay procedures.OBJETIVO: Avaliar o efeito da nitroglicerina tópica sobre a área viável de um modelo de retalho pré-fabricado por implante vascular em ratos e analisar o mecanismo de autonomização cirúrgica aplicada a retalhos pré-fabricados. MÉTODOS: Foram utilizados 40 ratos Wistar. No primeiro tempo cirúrgico - 20 ratos foram submetidos a implante do pedículo femoral na região subdérmica da parede abdominal, e 20 submetidos à autonomização cirúrgica de retalho cutâneo de parede abdominal e, simultaneamente, implante do pedículo femoral na região subdérmica deste retalho. No segundo tempo - após três semanas e em todos os animais

  15. Robust H∞ Control for Nonlinear Uncertain Switched Descriptor Systems with Time Delay and Nonlinear Input: A Sliding Mode Approach

    Directory of Open Access Journals (Sweden)

    Mourad Kchaou

    2017-01-01

    Full Text Available This paper addresses the problem of sliding mode control (SMC design for a class of uncertain switched descriptor systems with state delay and nonlinear input. An integral sliding function is designed and an adaptive sliding mode controller for the reaching motion is then synthesised such that the trajectories of the resulting closed-loop system can be driven onto a prescribed sliding surface and maintained there for all subsequent times. Moreover, based on a new Lyapunov-Krasovskii functional, a delay-dependent sufficient condition is established such that the admissibility as well as the H∞ performance requirement of the sliding mode dynamics can be guaranteed in the presence of time delay, external disturbances, and nonlinear input which comprises dead-zones and/or sector nonlinearities. The major contributions of this paper of this approach include (i the closed-loop system exhibiting strong robustness against nonlinear dynamics and (ii the control scheme enjoying the chattering-free characteristic. Finally, two representative examples are given to illustrate the theoretical developments.

  16. The 'reading man flap' for pressure sore reconstruction.

    Science.gov (United States)

    Sapountzis, Stamatis; Park, Hyoung Joon; Kim, Ji Hoon; Chantes, Achilleas; Beak, Rong Min; Heo, Chan Yeong

    2011-09-01

    The treatment of pressure sores represents a significant challenge to health care professionals. Although, pressure wound management demands a multidisciplinary approach, soft tissue defects requiring reconstruction are often considered for surgical management. Myocutaneous and fasciocutaneous flaps can provide stable coverage of pressure sores. Here, we describe our experience using a recent fasciocutaneous flap, which is named 'reading man' flap, in sacral, ischial, and trochanteric pressure sores. During a period of 1 year the authors operated 16 patients, 11 men, and 5 women, using the reading man flap. The ages of the patients ranged from 24 to 78 years. The location of pressure sores was 8 sacral, 5 ischial, and 3 trochanteric pressure sores. The mean size of pressure sores was 8 cm × 9 cm. All pressure sores covered bt the Reading Man flap healed asymptomatically. After follow-up of 2-8 months, no recurrences were encountered and no further surgical intervention was required. The reading man flap was found to be a useful technique for the closure of pressure sore in different anatomic locations. The advantage of tension-free closure and the minimal additional healthy skin excision made this flap a useful tool in pressure sore reconstructions.

  17. Mastectomy skin flap necrosis: challenges and solutions

    Science.gov (United States)

    Robertson, Stuart A; Jeevaratnam, Johann A; Agrawal, Avi; Cutress, Ramsey I

    2017-01-01

    Introduction Mastectomy skin flap necrosis (MSFN) has a reported incidence of 5%–30% in the literature. It is often a significant and underappreciated problem. The aim of this article was to review the associated challenges and possible solutions. Methods A MEDLINE search was performed using the search term “mastectomy skin flap necrosis”. Titles and abstracts from peer-reviewed publications were screened for relevance. Results MSFN is a common complication and may present as partial- or full-thickness necrosis. Predictive patient risk factors include smoking, diabetes, obesity, radiotherapy, previous scars and severe medical comorbidity. MSFN leads to a number of challenges, including wound management problems, delays to adjuvant therapy, esthetic compromise, implant extrusion, patient distress and financial loss. Careful preoperative planning and meticulous surgical technique may reduce the incidence of MSFN. A number of intraoperative techniques are available to try and predict skin flaps at risk of MSFN. MSFN may be managed operatively or nonoperatively. Early intervention may reduce the morbidity of MSFN in selected cases. Topical nitroglycerin ointment may be beneficial in reducing MSFN following immediate reconstruction, but the evidence base is still limited. Conclusion MSFN can result in considerable challenges for the patient and the health care service. This review discusses the management options for this problem. PMID:28331365

  18. Analysis of the delayed approach to the management of infected pancreatic necrosis

    Institute of Scientific and Technical Information of China (English)

    Nilesh Doctor; Sujith Philip; Vidhyachandra Gandhi; Maharra Hussain; Savio G Barreto

    2011-01-01

    AIM: To analyze outcomes of delayed single-stage necrosectomy after early conservative management of patients with infected pancreatic necrosis (IPN) associated with severe acute pancreatitis (SAP).METHODS: Between January 1998 and December 2009, data from patients with SAP who developed IPN and were managed by pancreatic necrosectomy wereanalyzed.RESULTS: Fifty-nine of 61 pancreatic necrosectomies were performed by open surgery and 2 laparoscopically.In 55 patients, single-stage necrosectomy couldbe performed (90.2%). Patients underwent surgery at a median of 29 d (range 13-46 d) after diagnosis of acute pancreatitis. Sepsis and multiple organ failure accounted for the 9.8% mortality rate. Pancreatic fistulae (50.8%) predominantly accounted for the morbidity. The median hospital stay was 23 d, and the median interval for return to regular activities was 110 d.CONCLUSION: This series supports the concept of delayed single-stage open pancreatic necrosectomy for IPN. Advances in critical care, antibiotics and interventional radiology have played complementary role in improving the outcomes.

  19. Robust control of uncertain nonlinear switched genetic regulatory networks with time delays: A redesign approach.

    Science.gov (United States)

    Moradi, Hojjatullah; Majd, Vahid Johari

    2016-05-01

    In this paper, the problem of robust stability of nonlinear genetic regulatory networks (GRNs) is investigated. The developed method is an integral sliding mode control based redesign for a class of perturbed dissipative switched GRNs with time delays. The control law is redesigned by modifying the dissipativity-based control law that was designed for the unperturbed GRNs with time delays. The switched GRNs are switched from one mode to another based on time, state, etc. Although, the active subsystem is known in any instance, but the switching law and the transition probabilities are not known. The model for each mode is considered affine with matched and unmatched perturbations. The redesigned control law forces the GRN to always remain on the sliding surface and the dissipativity is maintained from the initial time in the presence of the norm-bounded perturbations. The global stability of the perturbed GRNs is maintained if the unperturbed model is globally dissipative. The designed control law for the perturbed GRNs guarantees robust exponential or asymptotic stability of the closed-loop network depending on the type of stability of the unperturbed model. The results are applied to a nonlinear switched GRN, and its convergence to the origin is verified by simulation.

  20. A new bionic MAV's flapping motion based on fruit fly hovering at low Reynolds number

    Institute of Scientific and Technical Information of China (English)

    Peng Bai; Erjie Cui; Feng Li; Weijiang Zhou; Bingyan Chen

    2007-01-01

    On the basis of the studies on the high unsteadyaerody namic mechanisms of the fruit fly hovering the aerodynamic advantages and disadvantages of the fruit fly flapping motion were analyzed. A new bionic flapping motion was proposed to weaken the disadvantages and maintain the advantages, it may be used in the designing and manufacturing of the micro air vehicles (MAV's). The translation of the new bionic flapping motion is the same as that of fruit fly flapping motion. However, the rotation of the new bionic flapping motion is different. It is not a pitching-up rotation as the fruit fly flapping motion, but a pitching-down rotation at the beginning and the end of a stroke. The numerical method of 3rd-order Roe scheme developed by Rogers was used to study these questions. The correctness of the numerical method and the computational program was justified by comparing the present CFD results of the fruit fly flapping motion in three modes, i.e., the advanced mode, the symmetrical mode and the delayed mode, with Dickinson's experimental results. They agreed with each other very well.Subsequently, the aerodynamic characteristics of the new bionic flapping motion in three modes were also numerically simulated, and were compared with those of the fruit fly flapping. The conclusions could be drawn that the high unsteady lift mechanism of the fruit fly hovering is also effectively utilized by this new bionic flapping. Compared with the fruit fly flapping, the unsteady drag of the new flapping decreases very much and the ratio of lift to drag increases greatly. And the great discrepancies among the mean lifts of three flapping modes of the fruit fly hovering are effectively smoothed inthe new flapping. On the other hand, this new bionic flapping motion should be realized more easily. Finally, it must bepointed out that the above conclusions were just drawn forthe hovering flapping motion. And the aerodynamic characteristics of the new bionic flapping motion in forward

  1. Contralateral breast symmetrisation in unilateral DIEP flap breast reconstruction.

    Science.gov (United States)

    Wade, Ryckie G; Marongiu, Francesco; Sassoon, Elaine M; Haywood, Richard M; Ali, Rozina S; Figus, Andrea

    2016-10-01

    Women undergoing unilateral deep inferior epigastric artery perforator (DIEP) flap breast reconstruction may be offered a contralateral symmetrisation either at the time of reconstruction (simultaneous/immediate) or at a later stage (delayed). Simultaneous contralateral breast symmetrisation may be more beneficial to patients and healthcare institutions by avoiding staged surgery, although there is limited evidence on which to base practice. This deficit formed the rationale for our study. The primary outcome was the overall rate of revision surgery. Over a 6-year period, this prospective cohort study recorded the demographics, cancer treatments and operative outcomes of all consecutive unilateral DIEP flap breast reconstructions with or without contralateral symmetrising surgery. Patients were categorised into three groups: (1) simultaneous symmetrisation, 2) delayed symmetrisation and (3) no symmetrisation for comparative analysis. During the study period, 371 women underwent unilateral DIEP flap breast reconstruction 194 (52.3%) were not symmetrised, 155 (41.8%) were simultaneously symmetrised and 22 (5.9%) underwent delayed symmetrisation. Simultaneous symmetrisation of the contralateral breast and unilateral DIEP flap breast reconstruction increased the mean total operative time by 28 min. There were no differences in the rates of peri-operative complications. There were significantly higher rates of all-cause revision surgery (OR 3.97 [1.58, 9.94], p = 0.003) in women undergoing delayed symmetrisation, because of higher rates of revision lipomodelling, scar revision and revision contralateral symmetrisation. Simultaneous contralateral breast symmetrisation was associated with a lower risk of all-cause revision surgery. It is safe, beneficial and likely to be more cost-effective for women undergoing unilateral free DIEP flap breast reconstruction. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier

  2. Compliant topology optimization for planar passive flap micro valve.

    Science.gov (United States)

    Yoon, Gil Ho

    2014-10-01

    This paper reports the compliant topology optimization for planar passive flap micro valve considering fluid-structure interaction with a monolithic approach. Although flap valve type check valve is easy to manufacture and use for the applications for Bio/Nano/MEMS, its structural optimization has been seldom conducted so far. The size of the Bio/Nano/MEMS devices becomes smaller and the simple straight type micro valve structure is required to be optimized considering fluid speed. To address this optimization problem, the structural topology optimization scheme which designs optimal topologies is applied for a flap type check valve structure. To consider the coupling effects of fluid domain and structural domain, the monolithic finite element approach is employed. In the new analysis approach, solid domain is simulated by introducing the inverse permeability in the Navier-Stokes equation and the fluid stress filter in the linear elasticity equation. Also it is a new idea that fluid domain is simulated by finite elements with a weak Young's modulus in the linear elasticity equation. The mutual couplings between fluid and structure are considered by the introduction of the deformation tensor which is one of the basic concepts of the continuum mechanism. By distributing material properties inside a design domain for compliant flap, optimal flap structures can be constructed with different fluid speeds. By investigating the optimal layouts of several passive flap designs, we prove that the structural topology optimization can provide optimal layouts for Bio, Nano, and MEMS applications.

  3. Mastectomy skin flap necrosis: challenges and solutions

    Directory of Open Access Journals (Sweden)

    Robertson SA

    2017-03-01

    Full Text Available Stuart A Robertson,1 Johann A Jeevaratnam,2 Avi Agrawal,2 Ramsey I Cutress,3,4 1Department of Surgery, University Hospital Coventry and Warwickshire NHS Trust, Coventry, 2Department of Breast Surgery, Portsmouth Hospitals NHS Trust, Cosham, Portsmouth, 3Department of Breast Surgery, University Hospital Southampton NHS Foundation Trust, Princess Anne Hospital, 4Somers Cancer Research UK Centre, Southampton General Hospital Southampton, UK Introduction: Mastectomy skin flap necrosis (MSFN has a reported incidence of 5%–30% in the literature. It is often a significant and underappreciated problem. The aim of this article was to review the associated challenges and possible solutions. Methods: A MEDLINE search was performed using the search term “mastectomy skin flap necrosis”. Titles and abstracts from peer-reviewed publications were screened for relevance. Results: MSFN is a common complication and may present as partial- or full-thickness necrosis. Predictive patient risk factors include smoking, diabetes, obesity, radiotherapy, previous scars and severe medical comorbidity. MSFN leads to a number of challenges, including wound management problems, delays to adjuvant therapy, esthetic compromise, implant extrusion, patient distress and financial loss. Careful preoperative planning and meticulous surgical technique may reduce the incidence of MSFN. A number of intraoperative techniques are available to try and predict skin flaps at risk of MSFN. MSFN may be managed operatively or nonoperatively. Early intervention may reduce the morbidity of MSFN in selected cases. Topical nitroglycerin ointment may be beneficial in reducing MSFN following immediate reconstruction, but the evidence base is still limited. Conclusion: MSFN can result in considerable challenges for the patient and the health care service. This review discusses the management options for this problem. Keywords: mastectomy, flap, necrosis, complication, breast surgery

  4. On bifurcation delay: An alternative approach using Geometric Singular Perturbation Theory

    Science.gov (United States)

    Hsu, Ting-Hao

    2017-02-01

    To explain the phenomenon of bifurcation delay, which occurs in planar systems of the form x ˙ = ɛf (x , z , ɛ), z ˙ = g (x , z , ɛ) z, where f (x , 0 , 0) > 0 and g (x , 0 , 0) changes sign at least once on the x-axis, we use the Exchange Lemma in Geometric Singular Perturbation Theory to track the limiting behavior of the solutions. Using the trick of extending dimension to overcome the degeneracy at the turning point, we show that the limiting attracting and repulsion points are given by the well-known entry-exit function, and the minimum of z on the trajectory is of order exp ⁡ (- 1 / ɛ). Also we prove smoothness of the return map up to arbitrary finite order in ɛ.

  5. RFID-WSN integrated architecture for energy and delay- aware routing a simulation approach

    CERN Document Server

    Ahmed, Jameel; Tayyab, Muhammad; Nawaz, Menaa

    2015-01-01

    The book identifies the performance challenges concerning Wireless Sensor Networks (WSN) and Radio Frequency Identification (RFID) and analyzes their impact on the performance of routing protocols. It presents a thorough literature survey to identify the issues affecting routing protocol performance, as well as a mathematical model for calculating the end-to-end delays of the routing protocol ACQUIRE; a comparison of two routing protocols (ACQUIRE and DIRECTED DIFFUSION) is also provided for evaluation purposes. On the basis of the results and literature review, recommendations are made for better selection of protocols regarding the nature of the respective application and related challenges. In addition, this book covers a proposed simulator that integrates both RFID and WSN technologies. Therefore, the manuscript is divided in two major parts: an integrated architecture of smart nodes, and a power-optimized protocol for query and information interchange.

  6. DIEP Flap Breast Reconstruction Using 3-dimensional Surface Imaging and a Printed Mold

    Directory of Open Access Journals (Sweden)

    Koichi Tomita, MD, PhD

    2015-03-01

    Full Text Available Summary: Recent advances in 3-dimensional (3D surface imaging technologies allow for digital quantification of complex breast tissue. We performed 11 unilateral breast reconstructions with deep inferior epigastric artery perforator (DIEP flaps (5 immediate, 6 delayed using 3D surface imaging for easier surgery planning and 3D-printed molds for shaping the breast neoparenchyma. A single- or double-pedicle flap was preoperatively planned according to the estimated tissue volume required and estimated total flap volume. The DIEP flap was then intraoperatively shaped with a 3D-printed mold that was based on a horizontally inverted shape of the contralateral breast. Cosmetic outcomes were assessed as satisfactory, as confirmed by the postoperative 3D measurements of bilateral breasts. We believe that DIEP flap reconstruction assisted with 3D surface imaging and a 3D-printed mold is a simple and quick method for rebuilding a symmetric breast.

  7. Global-local optimization of flapping kinematics in hovering flight

    KAUST Repository

    Ghommem, Mehdi

    2013-06-01

    The kinematics of a hovering wing are optimized by combining the 2-d unsteady vortex lattice method with a hybrid of global and local optimization algorithms. The objective is to minimize the required aerodynamic power under a lift constraint. The hybrid optimization is used to efficiently navigate the complex design space due to wing-wake interference present in hovering aerodynamics. The flapping wing is chosen so that its chord length and flapping frequency match the morphological and flight properties of two insects with different masses. The results suggest that imposing a delay between the different oscillatory motions defining the flapping kinematics, and controlling the way through which the wing rotates at the end of each half stroke can improve aerodynamic power under a lift constraint. Furthermore, our optimization analysis identified optimal kinematics that agree fairly well with observed insect kinematics, as well as previously published numerical results.

  8. The Gradual Expansion Muscle Flap

    Science.gov (United States)

    2014-01-01

    defects can usu- ally be obtained with a rotational flap , larger size defects commonly require free tissue transfer. A number of techni- ques have...feasible.21,22 Because limb salvage situations occur in which rota- tional muscle coverage is inadequate and free flap coverage is less desirable, we...larger defects which previously would have required free tissue transfer. Surgical Technique The GEM flap for large soft tissue defects of the leg requires

  9. Sliding flap tracheoplasty.

    Science.gov (United States)

    Gates, G A; Tucker, J A

    1989-12-01

    The optimal method for surgical management of subglottic stenosis is based upon careful assessment of the location, caliber, length, and maturity of the stenotic segment, as well as associated conditions. For patients with a mature stenosis of short length, excision of the anterior arch of the cricoid and first ring and immediate reconstruction by means of a sliding flap of the next two to three rings of trachea offer a one-stage definitive treatment without the need for grafting. We report four cases of subglottic stenosis and one case of cricoid chondroblastoma in which reconstruction of the airway was successful and prompt. For carefully selected cases, sliding flap tracheoplasty may be a useful alternative to procedures in which the airway is expanded by means of grafting.

  10. Stability analysis of stochastic delayed cellular neural networks by LMI approach

    Energy Technology Data Exchange (ETDEWEB)

    Zhu Wenli [Department of Economic Mathematics, South Western University of Finance and Economics, Chengdu 610074 (China)]. E-mail: zhuwenli67@hotmail.com; Hu Jin [School of Applied Mathematics, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2006-07-15

    Some sufficient mean square exponential stability conditions for a class of stochastic DCNN model are obtained via the LMI approach. These conditions improve and generalize some existing global asymptotic stability conditions for DCNN model.

  11. Optimization of Kinematics of a Flapping Wing Mechanism

    Science.gov (United States)

    George, Ryan; Thomson, Scott; Mattson, Christopher; Colton, Mark; Tree, Mike

    2010-11-01

    Flapping flight offers several potential advantages over conventional fixed wing flight, such as agility and maneuverability in confined spaces, potentially decreased noise and detectability, and hovering capability. In this presentation, a water tunnel-based flapping wing apparatus is introduced that allows for arbitrary wing trajectories in three rotational degrees of freedom and simultaneous measurements of lift and thrust production. An optimal flapping trajectory for takeoff is found using hardware-in-the-loop optimization methodology. Wing motion derived from high-speed imaging of a ladybug during takeoff is used as a first iteration of the hardware-in-the-loop optimization. Using real-time force measurements and a gradient-based optimization approach, the algorithm searches for the optimal trajectory for a variety of parameters such as lift or efficiency. Hardware performance is assessed. Results from the optimization routine, including the final flapping trajectory are reported for both rigid and compliant wings.

  12. Cross finger flaps.

    Science.gov (United States)

    Kisner, W H

    1979-01-01

    Proper fingertip reconstruction requires good skin and soft tissue coverage, preservation of function and as normal an appearance as possible. The cross finger flap results in negligible joint stiffness, minimal morbidity and little work-time loss. An important factor is the conservation of finger length permitted by this technique. This method of repair is underutilized. It is indicated in several types of fingertip amputations where bone shortening would be detrimental.

  13. The Versatile Modiolus Perforator Flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Thomsen, Jorn Bo

    2016-01-01

    BACKGROUND: Perforator flaps are well established, and their usefulness as freestyle island flaps is recognized. The whereabouts of vascular perforators and classification of perforator flaps in the face are a debated subject, despite several anatomical studies showing similar consistency. In our....... The color Doppler ultrasonography study detected a sizeable perforator at the level of the modiolus lateral to the angle of the mouth within a radius of 1 cm. This confirms the anatomical findings of previous authors and indicates that the modiolus perforator is a consistent anatomical finding, and flaps...

  14. The Simplified Posterior Interosseous Flap.

    Science.gov (United States)

    Cavadas, Pedro C; Thione, Alessandro; Rubí, Carlos

    2016-09-01

    Several technical modifications have been described to avoid complications and simplify dissection. The authors describe some technical tips that make posterior interosseous flap dissection safer and more straightforward.

  15. Keystone flaps in coloured skin: Flap technology for the masses?

    Directory of Open Access Journals (Sweden)

    Satish P Bhat

    2013-01-01

    Full Text Available Introduction: Viscoelastic properties of skin in coloured ethnic groups are less favourable compared to Caucasians for executing Keystone flaps. Keystone flaps have so far been evaluated and reported only in Caucasians. The potential of Keystone flaps in a coloured ethnic group is yet unknown. Aim: This article reviews the experience to reconstruct skin defects presenting in a coloured ethnic group, by using Keystone flaps, with a review of existing literature. Design: Uncontrolled case series. Materials and Methods: This retrospective review involves 55 consecutive Keystone flaps used from 2009 to 2012, for skin defects in various locations. Patient demographic data, medical history, co-morbidity, surgical indication, defect features, complications, and clinical outcomes are evaluated and presented. Results: In this population group with Fitzpatrick type 4 and 5 skin, the average patient age was 35.73. Though 60% of flaps (33/55 in the series involved specific risk factors, only two flaps failed. Though seven flaps had complications, sound healing was achieved by suitable intervention giving a success rate of 96.36%. Skin grafts were needed in only four cases. Conclusions: Keystone flaps achieve primary wound healing for a wide spectrum of defects with an acceptable success rate in a coloured skin population with unfavorable biophysical properties. By avoiding conventional local flaps and at times even microsurgical flaps, good aesthetic outcome is achieved without additional skin grafts or extensive operative time. All advantages seen in previous studies were verified. These benefits can be most appreciated in coloured populations, with limited resources and higher proportion of younger patients and unfavorable defects.

  16. A hybrid RANS-LES approach with delayed-DES and wall-modelled LES capabilities

    Energy Technology Data Exchange (ETDEWEB)

    Shur, Mikhail L. [New Technologies and Services, 14, Dobrolyubov Avenue, 197198 St. Petersburg (Russian Federation); Spalart, Philippe R. [Boeing Commercial Airplanes, P.O. Box 3707, Seattle, WA 98124 (United States); Strelets, Mikhail Kh. [New Technologies and Services, 14, Dobrolyubov Avenue, 197198 St. Petersburg (Russian Federation)], E-mail: strelets@mail.rcom.ru; Travin, Andrey K. [New Technologies and Services, 14, Dobrolyubov Avenue, 197198 St. Petersburg (Russian Federation)

    2008-12-15

    A CFD strategy is proposed that combines delayed detached-eddy simulation (DDES) with an improved RANS-LES hybrid model aimed at wall modelling in LES (WMLES). The system ensures a different response depending on whether the simulation does or does not have inflow turbulent content. In the first case, it reduces to WMLES: most of the turbulence is resolved except near the wall. Empirical improvements to this model relative to the pure DES equations provide a great increase of the resolved turbulence activity near the wall and adjust the resolved logarithmic layer to the modelled one, thus resolving the issue of 'log layer mismatch' which is common in DES and other WMLES methods. An essential new element here is a definition of the subgrid length-scale which depends not only on the grid spacings, but also on the wall distance. In the case without inflow turbulent content, the proposed model performs as DDES, i.e., it gives a pure RANS solution for attached flows and a DES-like solution for massively separated flows. The coordination of the two branches is carried out by a blending function. The promise of the model is supported by its satisfactory performance in all the three modes it was designed for, namely, in pure WMLES applications (channel flow in a wide Reynolds-number range and flow over a hydrofoil with trailing-edge separation), in a natural DDES application (an airfoil in deep stall), and in a flow where both branches of the model are active in different flow regions (a backward-facing-step flow)

  17. Papilla Preservation Flap as Aesthetic Consideration in Periodontal Flap Surgery

    Directory of Open Access Journals (Sweden)

    Sandra Olivia

    2013-07-01

    Full Text Available Flap surgery is treatment for periodontal disease with alveolar bone destruction. Surgical periodontal flap with conventional incision will result in gingival recession and loss of interdental papillae after treatment. Dilemma arises in areas required high aesthetic value or regions with a fixed denture. It is challenging to perform periodontal flap with good aesthetic results and minimal gingival recession. This case report aimed to inform and to explain the work procedures, clinical and radiographic outcomes of surgical papilla preservation flap in the area that requires aesthetic. Case 1 was a surgical incision flap with preservation of papillae on the anterior region of teeth 11 and 12, with a full veneer crown on tooth 12. Case 2 was a surgical incision flap with preservation of papillae on the posterior region of tooth 46 with inlay restoration. Evaluation for both cases were obtained by incision papilla preservation of primary closure was perfect, good aesthetic results, minimal gingival recession and the interdental papillae can be maintained properly. In conclusion, periodontal flap surgery on the anterior region or regions that require high aesthetic value could be addressed with papilla preservation incision. Incision papilla preservation should be the primary consideration in periodontal flap surgery if possible.DOI: 10.14693/jdi.v19i3.144

  18. Immediate implant placement and provisionalization in the aesthetic zone using a flapless or a flap-involving approach: a randomized controlled trial.

    Science.gov (United States)

    Stoupel, Janet; Lee, Chun-Teh; Glick, Jaclyn; Sanz-Miralles, Elena; Chiuzan, Cody; Papapanou, Panos N

    2016-12-01

    We conducted a randomized controlled trial to compare the effect of flapless (FLS) or flap-involving (F) immediate placement and provisionalization of single-tooth implants in the aesthetic zone. Thirty-nine patients were randomized following extraction of a non-restorable tooth to a FLS or F group. All implants were immediately placed and provisionalized. We monitored prospectively changes in the peri-implant mucosal margin, the interproximal bone and buccal horizontal ridge at 3, 6 and 12 months. At 3 months post-surgery, the mean ± SD [median (interquartile range)] mesiobuccal peri-implant gingival margin recession from the pre-surgical soft tissue position amounted to 0.11 ± 0.32 mm [0 (0, 0.5)] in the FLS treatment arm versus 0.43 ± 37 mm [0.5 (0, 0.5)] in the F treatment arm (p = 0.02); corresponding values at the distobuccal surface were 0.11 ± 32 mm [0 (0, 0)] in the FLS arm versus 0.48 ± 0.44 mm [0.5 (0, 1)] in the F arm (p = 0.01). No other significant differences in soft or hard tissue remodelling between the treatment arms were observed at 3, 6 or 12 months. Flapless and a flap-involving immediate implant placement and provisionalization in the aesthetic zone resulted in comparable remodelling of the peri-implant mucosa, interproximal bone and buccal ridge at 6 and 12 months. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  19. Peroneal Flap for Tongue Reconstruction.

    Science.gov (United States)

    Lin, Ying-Sheng; Liu, Wen-Chung; Lin, Yaoh-Shiang; Chen, Lee-Wei; Yang, Kuo-Chung

    2017-07-01

    Background For large tongue defects, reconstructive surgeons have devised a variety of feasible options, such as radial forearm free flap and anterolateral thigh (ALT) flap. In our institution, peroneal flap has been the workhorse flap for the soft tissue defect in head and neck reconstruction. We present our experience using peroneal flap in tongue reconstruction. Patients and Methods The study included 47 patients who had undergone tongue reconstructions with peroneal flaps after tumor resection. The size and location of the defect after tumor resection determined whether the peroneal flaps could be harvested as pure septocutaneous flaps to solely reconstruct the neotongue or to carry an additional muscle bulk to fill the adjacent defect. Retrospective chart review was used to look for postoperative complications and to perform functional assessments (which were also performed through telephone inquiry). Results Of the 47 patients, 3 (6%) had flap failure and 1 (2.1%) had partial flap necrosis. The hemiglossectomy group had better results than the total glossectomy group with respect to speech and diet, but neither of these results reached statistical significance (p = 1.0 for speech and p = 0.06 for diet). The results of the subtotal glossectomy group were better than those of the total glossectomy group with respect to diet (p = 0.03). No statistically significant differences were noted among the three groups with respect to cosmetic aspect (p = 0.64). Conclusions Considering its reasonable postoperative complication rates and functional results, peroneal flap can be considered a feasible option for tongue reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  20. Thoracodorsal artery perforator fasciocutaneous flap: A versatile alternative for coverage of various soft tissue defects

    Directory of Open Access Journals (Sweden)

    Celalettin Sever

    2012-01-01

    Full Text Available Objective: The thoracodorsal artery perforator (TDAP flap has contributed to the efficient reconstruction of tissue defects that require a large amount of cutaneous tissue. The optimal reconstruction method should provide thin, and well-vascularized tissue with minimal donor-site morbidity. The indications for the use of this particular flap with other flaps are discussed in this article. Materials and Methods: Thirteen patients underwent soft tissue reconstruction using TDAP flaps between 2009 and 2011. Of those, there were four cases of antecubital burn contracture, three cases of axillary burn contracture, two cases of giant hair cell nevus of upper extremity, two cases of axillary reconstruction following severe recurrent hidradenitis, and two cases of crush injury. All patients were male and their ages ranged from 20 to 23 (average, 21 years. The mean follow-up period was 8 months (range, 4-22 months. Results: All reconstructive procedures were completed without any major complications. Minor complications related to transfered flaps were wound dehiscence in one case, transient venous congestion in two cases. Minor complication related to the donor site was seroma in one case. The success rate was 100%, with satisfactory cosmetic results. Conclusions: The TDAP flap is a safe and extremely versatile flap that offers significant advantages in acute and delayed reconstruction. Although the vascular anatomy may be variable, free and pedicled TDAP flap is a versatile alternative for soft tissue defects. It adapts very well to the soft tissue defects with acceptable donor site scar.

  1. Sliding mode control of uncertain systems with distributed time-delay: parameter-dependent Lyapunov functional approach

    Institute of Scientific and Technical Information of China (English)

    Ligang WU; Changhong WANG; Huijun GAO; Qingshuang ZENG

    2006-01-01

    The robust stability and robust sliding mode control problems are studied for a class of linear distributed time-delay systems with polytopic-type uncertainties by applying the parameter-dependent Lyapunov functional approach combining with a new method of introducing some relaxation matrices and tuning parameters, which can be chosen properly to lead to a less conservative result. First, a sufficient condition is proposed for robust stability of the autonomic system;next, the sufficient conditions of the robust stabilization controller and the existence condition of sliding mode are developed. The results are given in terms of linear matrix inequalities (LMIs), which can be solved via efficient interior-point algorithms. A numerical example is presented to illustrate the feasibility and advantages of the proposed design scheme.

  2. Different Types of Projective Synchronization in a Class of Time-Delayed Chaotic Systems Using Active Control Approach

    Institute of Scientific and Technical Information of China (English)

    FENG Cun-Fang; WANG Ying-Hai

    2011-01-01

    We study different types of projective synchronization (projective-anticipating, projective, and projectivelag synchronization) in a class of time-delayed chaotic systems related to optical bistable or hybrid optical bistable devices.We relax some limitations of previous work, where the scaling factor a can not be any desired value.In this paper, we achieve projective-anticipating, projective, and projective-lag synchronization without the limitation of α.A suitable controller is chosen using active control approach.Based on the Lyapunov stability theory, we derive the sutficient stability condition through theoretical analysis.The analytical results are validated by the numerical simulations using Ikeda model and Mackey-Glass model.

  3. Guaranteed cost consensus protocol design for linear multi-agent systems with sampled-data information: An input delay approach.

    Science.gov (United States)

    Zhao, Yadong; Zhang, Weidong

    2017-03-01

    To investigate the energy consumption involved in a sampled-data consensus process, the problem of guaranteed cost consensus for sampled-data linear multi-agent systems is considered. By using an input delay approach, an equivalent system is constructed to convert the guaranteed cost consensus problem to a guaranteed cost stabilization problem. A sufficient condition for guaranteed cost consensus is given in terms of linear matrix inequalities (LMIs), based on a refined time-dependent Lyapunov functional analysis. Reduced-order protocol design methodologies are proposed, with further discussions on determining sub-optimal protocol gain and enlarging allowable sampling interval bound made as a complement. Simulation results illustrate the effectiveness of the theoretical results.

  4. Pathological internal mammary lymph nodes in secondary and tertiary deep inferior epigastric perforator flap breast reconstructions.

    Science.gov (United States)

    Hofer, Stefan O P; Rakhorst, Hinne A; Mureau, Marc A M; Moolenburgh, Sanne E; van Huizum, Martine A; van Geel, Albert N

    2005-12-01

    Use of internal mammary vessels during breast reconstruction provides information on part of the internal mammary chain lymph nodes (LNs). It was evaluated whether our current practice of screening should be changed to identify those delayed breast reconstruction patients with tumor-positive internal mammary nodes (IMNs) and whether breast reconstruction should be continued, in case suspicious IMNs were found intraoperatively. From February 2002 to December 2004, 81 patients had received 98 deep inferior epigastric perforator flaps for delayed breast reconstruction. Prospectively collected data for suspicious internal mammary LNs were evaluated. In 13 patients (16%) who had received a delayed breast reconstruction, macroscopically suspicious LNs were detected in the course of the internal mammary chain. Three patients (4%) had a pathologic diagnosis of malignancy, which was found to match their primary tumor. No relationship between positive internal mammary chain LNs and location of the primary tumor, TNM-stage, or previously administered adjuvant therapy was found. Suspicious internal mammary chain LNs found during recipient vessel dissection for breast reconstruction can have important consequences for treatment of malignant disease in individual patients. Presented data do not support changing the current perioperative approach of delayed breast reconstruction.

  5. Stroke prevention and cognitive reserve: emerging approaches to modifying risk and delaying onset of dementia

    Directory of Open Access Journals (Sweden)

    Kevin eWillis

    2013-03-01

    Full Text Available Demographic changes and improvements in health care are projected to result in dramatic increases in the prevalence of dementia. Alzheimer’s disease is widely considered to be the primary cause of dementia - a disease for which there is currently no cure nor effective treatment, and for which it is thought that little can be done to mitigate risk. However, an increasing understanding of the role and extent of vascular contributions to the development of dementia, and appreciation of the interactions between stroke and Alzheimer’s disease, suggest that targeting vascular risk factors may be very beneficial in reducing the impact of dementia. We also describe how active stimulation of the brain throughout the life course builds cognitive reserve that can offset or compensate for cognitive decline in later life. Finally, we discuss the implications of these emerging approaches for dementia prevention and advocate for the urgent implementation of more extensive public health strategies to improve vascular health.

  6. 14 CFR 23.701 - Flap interconnection.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap interconnection. 23.701 Section 23.701... Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a system must— (1) Be synchronized by a mechanical interconnection between the movable flap surfaces that...

  7. Skin flaps and grafts - self-care

    Science.gov (United States)

    ... Regional flaps - self-care; Distant flaps - self-care; Free flap - self-care; Skin autografting - self-care; Pressure ulcer ... your wound To care for the graft or flap site: You may need to rest ... around it clean and free from dirt or sweat. DO NOT let the ...

  8. Flapping wing actuation using resonant compliant mechanisms: An insect-inspired design

    NARCIS (Netherlands)

    Bolsman, C.T.

    2010-01-01

    The realization of a wing actuation mechanism for a flapping wing micro air vehicle requires a move away from traditional designs based on gears and links. An approach inspired by nature’s flyers is better suited. For flapping flight two wing motions are important: the sweeping and the pitching moti

  9. Flight tests of a rotating cylinder flap on a North American Rockwell YOV-10 aircraft

    Science.gov (United States)

    Cichy, D. R.; Harris, J. W.; Mackay, J. K.

    1972-01-01

    Flight tests were conducted of a twin engine airplane modified to a STOL configuration with rotating cylinder flaps and interconnected propellers. The flight tests included verification of the functional operation of the rotating cylinder flap system and the determination of the low speed flying qualities and performance characteristics with emphasis on approach and landing.

  10. DIEP flap with implant: a further option in optimising breast reconstruction.

    Science.gov (United States)

    Figus, Andrea; Canu, Vanessa; Iwuagwu, Fortune C; Ramakrishnan, Venkat

    2009-09-01

    Recent advances in breast reconstruction allow for high expectations regarding long-term symmetry and aesthetic appearance. The DIEP flap is currently considered as an ideal autologous reconstruction. However, there are situations in which the amount of tissue from a DIEP flap is not enough to achieve adequate symmetry. Indications and outcomes for a combined use of DIEP flap and implants are discussed in order to describe and examine a further scenario in optimising breast reconstruction. Between January 2004 and January 2006, all patients who underwent combined DIEP/implant breast reconstruction have been collected and followed prospectively. When clinical assessment demonstrated inadequate amount of tissue in the abdominal region to achieve a suitable unilateral or bilateral reconstruction with DIEP flaps, the patients were counselled about the opportunity of primary augmentation of the DIEP flaps. In cases where DIEP breast reconstruction has been done previously and there is a considerable asymmetry, delayed flap augmentation was considered. Patient's age, indication for surgery, preoperative and postoperative radiotherapy (RT), operative procedure, implant size, location and timing of insertion, complications, outcomes, and follow-up have been gathered. In all cases, textured round silicone gel implants have been used. After 12 months, four-point scales were used to analyse patients' satisfaction and aesthetic outcome. During the study period, 156 patients underwent breast reconstruction with 174 DIEP flaps. Fourteen patients (8.9%) had breast reconstruction with 19 DIEP flaps and 18 implants. The mean follow-up was 20.6 months (range 12-32 months). Fourteen implants were placed primarily at the time of DIEP reconstruction. The average implant weight was 167.2g with range between 100 and 230 g. Implant/flap weight ratio is about 1:5 corresponding to 20%. In six flaps, the patients had RT before the reconstruction, whilst in three cases of delayed DIEP flap

  11. Analysis of delayed convergence in the three-noded Timoshenko beam element using the function space approach

    Indian Academy of Sciences (India)

    Somenath Mukherjee; Gangan Prathap

    2002-10-01

    Despite satisfying only completeness and continuity requirements, elements often perform erroneously in a certain class of problems, called the locking situations, where they display spurious stress oscillations and enhanced stiffness properties. The function space approach that effectively substantiates the postulates of the field consistency paradigm is an efficient tool to reveal the fundamental cause of locking phenomena, and propose methods to eliminate this pathological problem. In this paper, we review the delayed convergence behaviour of three-noded Timoshenko beam elements using the rigorous function space approach. Explicit, closed form algebraic results for the element strains, stresses and errors have been derived using this method. The performance of the field-inconsistent three-noded Timoshenko beam element is compared with that of the field-inconsistent twonoded beam element. It is demonstrated that while the field-inconsistent two-noded linear element is prone to shear locking, the field-inconsistent three-noded element is not very vulnerable to this pathological problem, despite the resulting shear oscillations.

  12. Noise Radiation from a Continuous Mold-Line Link Flap Configuration

    Science.gov (United States)

    Hutcheson, Florence V.; Brooks, Thomas F.; Humphreys, William M., Jr.

    2011-01-01

    The results of an experimental study of the noise from a Continuous Mold-Line Link (CML) flap are presented. Acoustic and unsteady surface pressure measurements were performed on a main element wing section with a half-span CML flap in NASA Langley s Quiet Flow Facility. The acoustic data were acquired with a medium aperture directional array (MADA) of microphones. The Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) method is applied to determine the spatial distribution and strength of the noise sources over the surface of the test model. A Coherent Output Power (COP) method which relates the output from unsteady surface pressure sensors to the output of the MADA is also used to obtain more detailed characteristics of the noise source distribution in the trailing edge region of the CML. These results are compared to those obtained for a blunt flap to quantify the level of noise benefit that is achieved with the CML flap. The results indicate that the noise from the CML region of the flap is 5 to 17 dB lower (depending on flap deflection and Mach number) than the noise from the side edge region of the blunt flap. Lower noise levels are obtained for all frequencies. Spectral analysis of the noise from the cove region of the CML and blunt flap models also reveal a spectral peak in the high frequency range that is related to noise scattering at the trailing edge of the main element. The peaks in the CML and blunt flap cove noise spectra are close in level and often exceed blunt side edge noise. Applying a strip of serrated tape to the trailing edge of the CML flap model main airfoil reduced the peak but increased other noise somewhat. Directivity measurements show that the CML flap can be more directional than the blunt flap.

  13. Thoraco-epigastric flap for breast reconstruction in cancer

    Directory of Open Access Journals (Sweden)

    A. D. Zikiryakhodzhayev,

    2015-01-01

    Full Text Available Reconstructive surgery for breast cancer are an integral method of rehabilitation of cancer patients. Breast reconstruction may be delayed and instantaneous. The article presents a description of the thoraco-epigastric flap for breast reconstruction in cancer. The operation involves the replacement of the remote volume (after radical resection of the breast and the breast skin adjacent tissues adjacent to the inframammary crease from the side of the anterior abdominal wall. Surgery is indicated when the tumor in the lower parts of the breast, closest to the skin, in combination with small size breast cancer. The article presents a clinical example of this operation. Described in detail the operation, received a good cosmetic result. The advantage of the application of thoraco-epigastric flap is in the simplicity of the technique of its execution, good blood supply, donor wound is easily sutured due to the possible wide separating cellular adjacent skin and subcutaneous tissue. The disadvantage of this method is limited and the need for careful monitoring of perforating branches of the upper epigastric artery. Thus, thoraco-epigastric flap, can be applicable when performing reconstructive operations for breast cancer in compliance with the necessary requirements for the formation of the flap and the correct attitude to feeding the flap vessels, and virtually eliminates possible complications with the healing of the flap. Undoubtedly, reconstructive plastic surgery for breast cancer, during the testimony and technical capabilities, are an essential component of surgical treatment.

  14. Versatility of radial forearm free flap for intraoral reconstruction

    Directory of Open Access Journals (Sweden)

    Jeremić Jelena V.

    2015-01-01

    Full Text Available Introduction. The radial forearm free flap has an important role in reconstruction of the oncologic defects in the region of head and neck. Objective. The aim was to present and evaluate clinical experience and results in the radial forearm free transfer for intraoral reconstructions after resections due to malignancies. Methods. This article illustrates the versatility and reliability of forearm single donor site in 21 patients with a variety of intraoral oncologic defects who underwent immediate (19 patients, 90.5% or delayed (2 patients, 9.5% reconstruction using free flaps from the radial forearm. Fascio-cutaneous flaps were used in patients with floor of the mouth (6 cases, buccal mucosa (5 cases, lip (1 case and a retromolar triangle (2 cases defects, or after hemiglossectomy (7 cases. In addition, the palmaris longus tendon was included with the flap in 2 patients that required oral sphincter reconstruction. Results. An overall success rate was 90.5%. Flap failures were detected in two (9.5% patients, in one patient due to late ischemic necrosis, which appeared one week after the surgery, and in another patient due to venous congestion, which could not be salvaged after immediate re-exploration. Two patients required re-exploration due to vein thrombosis. The donor site healed uneventfully in all patients, except one, who had partial loss of skin graft. Conclusion. The radial forearm free flap is, due to multiple advantages, an acceptable method for reconstructions after resection of intraoral malignancies. [Projekat Ministarstva nauke Republike Srbije, br. 41006

  15. The Value of the "Papillon" Anterolateral Thigh Flap for Total Pharyngolaryngectomy Reconstruction: A Retrospective Case Series.

    Science.gov (United States)

    Ghazali, Naseem; Hanna, Todd C; Dyalram, Donita; Lubek, Joshua E

    2016-02-01

    The tubed, buried anterolateral thigh (ALT) flap is a popular reconstruction method for total pharyngolaryngectomy defects. The "papillon"-designed ALT flap, described by Hayden et al, offers an alternative method of using the ALT flap in this situation. We report our early experience with the papillon ALT flap in a patient cohort. On retrospective review, all patients who underwent reconstruction of circumferential total pharyngolaryngectomy defects with the papillon ALT flap from February 2012 to February 2015 were identified from our departmental database. Demographic and clinical data, operative details, and complications were analyzed from the records. Seven patients were included in this study. The mean length of hospital stay was 15 days (range, 10 to 32 days). Acute complications occurred in 5 of 7 patients, namely, partial flap loss managed by a pectoralis flap (1 of 7 [14%]); an early pharyngocutaneous fistula (4 of 7 [57%]) managed by simple repair, wound packing, or delayed repair; and a donor-site hematoma (1 of 7 [14%]). At follow-up (range, 2 to 24 months), there was 1 stricture formation, but no chronic fistula. All patients were able to swallow orally. Early results using the papillon ALT flap suggest that this technique is a viable alternative to the standard tubed ALT flap design. The advantages of this design include the following: 1) it offers simultaneous vascularized skin to resurface anterior neck skin deficiency without resorting to additional tissue elsewhere; 2) direct monitoring of the ALT flap is possible; and 3) any pharyngocutaneous fistula is exteriorized to the surface without compromising the internal neck structures and can be easily identified and repaired directly in the office. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  16. Flap Edge Noise Reduction Fins

    Science.gov (United States)

    Khorrami, Mehdi R. (Inventor); Choudhan, Meelan M. (Inventor)

    2015-01-01

    A flap of the type that is movably connected to an aircraft wing to provide control of an aircraft in flight includes opposite ends, wherein at least a first opposite end includes a plurality of substantially rigid, laterally extending protrusions that are spaced apart to form a plurality of fluidly interconnected passageways. The passageways have openings adjacent to upper and lower sides of the flap, and the passageways include a plurality of bends such that high pressure fluid flows from a high pressure region to a low pressure region to provide a boundary condition that inhibits noise resulting from airflow around the end of the flap.

  17. Dancing girl flap: a new flap suitable for web release.

    Science.gov (United States)

    Shinya, K

    1999-12-01

    To create a deep web, a flap must be designed to have a high elongation effect in one direction along the mid-lateral line of the finger and also to have a shortening effect in the other direction, crossing at a right angle to the mid-lateral line. The dancing girl flap is a modification of a four-flap Z-plasty with two additional Z-plasties. It has a high elongation effect in one direction (>550%) and a shortening effect in the other direction at a right angle (<33%), creating a deep, U-shaped surface. This new flap can be used to release severe scar contracture with a web, and is most suitable for incomplete syndactyly with webs as high as the proximal interphalangeal joint.

  18. Comment on "Generalized projective synchronization in time-delayed systems: nonlinear observer approach" [Chaos 19, 013102 (2009); 20, 029902 (2010)].

    Science.gov (United States)

    Theesar, S Jeeva Sathya; Balasubramaniam, P; Banerjee, Santo

    2012-09-01

    In Chaos 19, 013102 (2009), the author proposed generalized projective synchronization for time delay systems using nonlinear observer and obtained sufficient condition to ensure projective synchronization for modulated time varying delay. There are concerns with the obtained conditions as the result was applicable only to trivial case of time varying delay τ[over dot](1)(t)=dτ(1)(t)/dt<1. In this paper, we note the drawbacks of the proposed sufficient condition. The new improved sufficient condition for ensuring the projective synchronization of time varying delayed systems is presented. The proposed new criteria have been verified by adopting the Ikeda system.

  19. Root coverage in class I gingival recession defects, combining rotated papillary pedicle graft and coronally repositioned flap, using a micro surgical approach: A clinical evaluation

    Directory of Open Access Journals (Sweden)

    Latha Tella

    2009-01-01

    Full Text Available Background: The purpose of this case study was to evaluate the success and predictability of a rotated papillary pedicle graft in combination with the coronally advanced flap using surgical loupe (2.5X magnification for the treatment of Miller′s class I gingival recession. Materials and Methods: Fifteen systemically healthy patients with isolated gingival recession underwent the procedure. The probing depth, percentage root coverage, width of the keratinized gingiva and the gain in clinical attachment, papilla width, papilla height, area of the papilla at the donor site, were recorded at baseline, 3 months and 12 months. Results: All parameters except probing pocket depth, significantly improved from baseline to 12 months. The mean recession defect of 2.67 ± 0.03 mm present at baseline reduced to 0.13 ± 0.35 mm at the end of the 3 rd months and stabilized at 0.27 ± 0.59 mm at 12 months. The mean reduction in recession depth was 2.40 ± 0.03 mm at the end of the study. Complete recession coverage was obtained in 13 of the 15 (87% of the cases treated with a mean percentage recession coverage at 12 months being 86 ± 35.19%. The gain in the width of the keratinized gingiva was 1.33 ± 0.13 mm at the end of the study. There was no postoperative morbidity from where the graft was harvested at the end of the study period. Conclusion: The use of magnification in mucogingival surgery resulted in achieving a high degree of success and predictability as well as an excellent esthetic outcome.

  20. Reverse flow first dorsal metacarpal artery flap for covering the defect of distal thumb.

    Science.gov (United States)

    Checcucci, Giuseppe; Galeano, Mariarosaria; Zucchini, Maura; Zampetti, Pier Giuseppe; Ceruso, Massimo

    2014-05-01

    Reconstruction of distal thumb injuries still remains a challenge for hand surgeons. Surgical treatment includes the use of local, regional, and free flaps. The purpose of this report is to present the results of the use of a sensitive reverse flow first dorsal metacarpal artery (FDMA) flap. The skin flap was designed on the radial side of the proximal phalanx of the index finger based on the ulnar and radial branch of the FDMA and a sensory branch of the superficial radial nerve. This neurovascular flap was used in five patients to cover distal soft-tissue thumb defects. All flaps achieved primary healing except for one patient in whom superficial partial necrosis of the flap occurred, and the defect healed by second intention. All patients maintained the thumb original length and were able to return to their previous daily activities. The reverse flow FDMA flap is a reliable option to cover immediate and delayed defects of distal thumb, offering acceptable functional and cosmetic outcomes in respect to sensibility, durability, and skin-match.

  1. Effect of botulinum toxin A and nitroglycerin on random skin flap survival in rats.

    Science.gov (United States)

    Ghanbarzadeh, Kourosh; Tabatabaie, Omid Reza; Salehifar, Ebrahim; Amanlou, Massoud; Khorasani, Ghasemali

    2016-01-01

    A suitable pharmacological substitute for the well-established surgical delay technique for random skin flaps to increase viability has been elusive. To evaluate the effects of nitroglycerin and botulinum toxin type A on random flap survival in a rat model. The present controlled experimental study was performed in the four groups of rats. One week after intervention in each group, the flap was raised and kept in situ, and flap necrosis was evaluated through follow-up. Group 1 received intradermal botulinum toxin type A (BTX-A) and topical nitroglycerin 2%; group 2 received BTX-A and topical Vaseline (Unilever, USA); group 3 received topical nitroglycerin and intradermal normal saline; and group 4 received topical Vaseline and intradermal normal saline. BTX-A reduced the area of necrosis compared with control (24% versus 56% respectively; P<0.001). Nitroglycerin application was associated with a trend toward improved flap viability (42% versus 56%; P=0.059). The combination of topical nitroglycerin and BTX-A, compared with Vaseline and BTX-A, was associated with decreased flap necrosis (16.1% versus 24%, respectively), although it was not statistically significant (P=0.45). BTX-A was effective in reducing distal flap necrosis. The effect of BTX-A was significantly more pronounced than nitroglycerin ointment.

  2. Free toe pulp flap for finger pulp and volar defect reconstruction

    Directory of Open Access Journals (Sweden)

    Jyoshid R Balan

    2016-01-01

    Full Text Available Background: Fingertip injury requiring flap cover is very common in the modern era. The ideal cover should fulfill both functional and aesthetic improvement. Materials and Methods: From June 2015 to April 2016, we performed seven free toe pulp flaps for finger defect reconstruction. All patients were males. Five flaps were done in emergency post-traumatic cases, and two were done in elective set up. The cases included reconstruction of three thumbs, one index and one ring finger in an emergency set up and two ring fingers in the elective. Thumb reconstruction was done with great toe lateral pulp and the other digits reconstructed with second toe pulp flap. Follow-up evaluation included both functional and aesthetic assessment. Results: Five flaps survived completely, one suffered partial loss, and one flap failed completely. The median follow-up period was 9 months. The median duration of surgery was 255 min (range 210 to 300 min. The median two-point discrimination was 6.5 mm (range 4–8 mm. There was the return of temperature sensation in all patients; two had cold intolerance. The Semmes-Weinstein monofilament score varied from 3.61 to 5.07 (median filament index value 4.31/pressure value of 2 g/mm2. Three patients had delayed donor site wound healing. Conclusions: The free toe pulp flap is an efficient choice for fingertip and volar finger defects reconstruction with an excellent tissue match.

  3. Monolithically Integrated Micro Flapping Vehicles

    Science.gov (United States)

    2012-08-01

    Mechanical Logic • Memory Mm-Scale Ground Mobility Actuation & Mechanisms Ultrasonic Motors Reversible Adhesion Platform Design...MEMS Mm-Scale Ground Mobility PiezoMEMS Haltere Actuation & Mechanisms Ultrasonic Motors Reversible Adhesion Platform Design Flapping

  4. Robust H-infinity filtering for time-delay systems With missing measurements: a parameter-dependent approach

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Robust H-infinity filtering for a class of uncertain discrete-time linear systems with time delays and missing measurements is studied in this paper.The uncertain parameters are supposed to reside in a convex polytope and the missing measurements are described by a binary switching sequence sarisfying a Bernoulli distribution.Our attention is focused on the analysis and design of robust H-infinity filters such that,for all admissible parameter uncertainties and all possible missing measurements,the filtering error system is exponentially mean-square stable with a prescribed H-infinity disturbance attenuation level.A parameter-dependent approach is proposed to derive a less conservative result.Sufficient conditions are established for the existence of the desired filter in terms of certain linear matrix inequalities (LMIs).When these LMIs are feasible,an explicit expression of the desired filter is also provided.Finally,a numerical example is presented to illustrate the effectiveness and applicability of the proposed method.

  5. Active Control of Long Bridges Using Flaps

    DEFF Research Database (Denmark)

    Hansen, H. I.; Thoft-Christensen, Palle

    The main problem in designing ultra-long span suspension bridges is flutter. A solution to this problem might be to introduce an active flap control system to increase the flutter wind velocity. The investigated flap control system consists of flaps integrated in the bridge girder so each flap...... is the streamlined part of the edge of the girder. Additional aerodynamic derivatives are shown for the flaps and it is shown how methods already developed can be used to estimate the flutter wind velocity for a bridge section with flaps. As an example, the flutter wind velocity is calculated for different flap...... configurations for a bridge section model by using aerodynamic derivatives for a flat plate. The example shows that different flap configurations can either increase or decrease the flutter wind velocity. for optimal flap configurations flutter will not occur....

  6. OUR PRELIMINARY EXPERIENCE WITH A NEW METHOD OF DIEAp FLAP DISSECTION.

    Science.gov (United States)

    Hýža, P; Veselý, J; Streit, L; Schwarz, D; Kubek, T; Catalano, F; Lombardo, G A G

    The abdominal tissue is an ideal source for autologous breast reconstruction. We propose a new approach for intramuscular dissection of a DIEP flap in this paper. A total of 84 women underwent breast reconstruction after mastectomy. From this group, 49 patients were treated with traditional DIEP flap of which 21 had unilateral procedure and 28 had bilateral procedure. This new type of dissection was performed in 35 women, with unilateral approach in 14 cases and bilateral approach in 21 cases. The statistical differences are not significant in the two groups with regards to complications (p > 0.1). Mean operative time in this new approach was 3 hours and 10 minutes per flap. Mean operative time in the traditional dissection of DIEP was 3 hours and 41 minutes per flap. The operative time of the new approach is significantly shorter than the dissection of the traditional DIEP flap (p dissection proposed by the authors is a new concept in autologous breast reconstruction. In this type of dissection no fascia is resected and it is more reliable than a traditional DIEP flap for the ease of dissection and for the presence of a small protective cuff of muscle around the vessel with a lower risk of perforator injury.It is a reproducible option of dissection, useful also in less experienced hands and it is a time reducing technique compared with the traditional DIEP flap.

  7. The rat saphenous flap: a fasciocutaneous free flap model without panniculus carnosus.

    Science.gov (United States)

    Mutaf, M; Tasaki, Y; Tanaka, K; Fujii, T

    1995-10-01

    The rat saphenous flap is described as a new experimental model for free flap studies. This is a fasciocutaneous free flap based on the saphenofemoral vascular pedicle. The flap may include the entire medial aspect of the lower leg between the knee and ankle. Thirty flaps were harvested from 15 inbred rats. Each flap was transferred to the anterior neck of a recipient rat of the same inbred strain so that 15 flaps were vascularized free flaps using the standard end-to-end microvascular technique and the other 15 flaps were nonvascularized free grafts. All but two (technical failure) of the vascularized flaps showed complete survival, whereas all nonvascularized flaps completely necrosed 2 weeks after transfer. It was concluded that the rat saphenous flap has several advantages such as a long and consistent vascular pedicle, ease of harvest, and an all-or-none survival pattern. Furthermore, as a unique feature of this flap, histological analysis revealed that the rat saphenous flap is composed of the skin and underlying fascia without panniculus carnosus. We therefore suggest that the rat saphenous flap is the first true fasciocutaneous free flap model in the rat. In this paper, in addition to illustrating the anatomy of the saphenous vessels and describing a new fasciocutaneous free flap model based on these vessels, we have documented some anatomical details of the rat leg that have never been described in the literature related to the rat anatomy.

  8. The evolution of perforator flap breast reconstruction: twenty years after the first DIEP flap.

    Science.gov (United States)

    Healy, Claragh; Allen, Robert J

    2014-02-01

    It is over 20 years since the inaugural deep inferior epigastric perforator (DIEP) flap breast reconstruction. We review the type of flap utilized and indications in 2,850 microvascular breast reconstruction over the subsequent 20 years in the senior author's practice (Robert J. Allen). Data were extracted from a personal logbook of all microsurgical free flap breast reconstructions performed between August 1992 and August 2012. Indication for surgery; mastectomy pattern in primary reconstruction; flap type, whether unilateral or bilateral; recipient vessels; and adjunctive procedures were recorded. The DIEP was the most commonly performed flap (66%), followed by the superior gluteal artery perforator flap (12%), superficial inferior epigastric artery perforator flap (9%), inferior gluteal artery perforator flap (6%), profunda artery perforator flap (3%), and transverse upper gracilis flap (3%). Primary reconstruction accounted for 1,430 flaps (50%), secondary 992 (35%), and tertiary 425 (15%). As simultaneous bilateral reconstructions, 59% flaps were performed. With each flap, there typically ensues a period of enthusiasm which translated into surge in flap numbers. However, each flap has its own nuances and characteristics that influence patient and physician choice. Of note, each newly introduced flap, either buttock or thigh, results in a sharp decline in its predecessor. In this practice, the DIEP flap has remained the first choice in autologous breast reconstruction. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  9. Buried free flaps in head and neck reconstruction: higher risk of free flap failure?

    Science.gov (United States)

    Reiter, M; Harréus, U; Kisser, U; Betz, C S; Baumeister, Ph

    2017-01-01

    Thrombosis of the pedicle is central to free flap failure, and early revision of a compromised flap is the key to successfully salvage a flap. Therefore, the majority of free flaps in reconstructive head and neck surgery are used with the ability to visually examine the flap. Sometimes, due to intra-operative circumstances, it is necessary to use a flap that cannot be monitored externally. These flaps are called buried flaps and have the reputation of being put at risk. The current literature provides only limited data to support or disprove this position. A single institution retrospective review of patient charts between 2007 and 2015 was performed. Flap monitoring was carried out with hand-held Doppler of the pedicle hourly for the first 72 h in all cases. Additional duplex ultrasound was performed in the majority of buried flaps. A total of 437 flaps were included into the study. 37 flaps (7.8 %) were identified to fulfill the criteria of a buried free flap. In total, four patients had complications, three of which required operative reexploration. All interventions were successful, resulting in no flap loss in our series. An accurate operation technique combined with meticulous monitoring protocols supported by duplex ultrasound can result in satisfactory outcome of buried flaps. No enhanced risk of flap loss of buried flaps was found in our cohort.

  10. Microvascular free flaps in the management of war wounds with tissue defects

    Directory of Open Access Journals (Sweden)

    Kozarski Jefta

    2003-01-01

    Full Text Available Background. War wounds caused by modern infantry weapons or explosive devices are very often associated with the defects of soft and bone tissue. According to their structure, tissue defects can be simple or complex. In accordance with war surgical doctrine, at the Clinic for Plastic Surgery and Burns of the Military Medical Academy, free flaps were used in the treatment of 108 patients with large tissue defects. With the aim of closing war wounds, covering deep structures, or making the preconditions for reconstruction of deep structures, free flaps were applied in primary, delayed, or secondary term. The main criteria for using free flaps were general condition of the wounded, extent, location, and structure of tissue defects. The aim was also to point out the advantages and disadvantages of the application of free flaps in the treatment of war wounds. Methods. One hundred and eleven microvascular free flaps were applied, both simple and complex, for closing the war wounds with extensive tissue defects. The main criteria for the application of free flaps were: general condition of the wounded, size, localization, and structure of tissue defects. For the extensive defects of the tissue, as well as for severely contaminated wounds latissimus dorsi free flaps were used. For tissue defects of distal parts of the lower extremities, scapular free flaps were preferred. While using free tissue transfer for recompensation of bone defects, free vascularized fibular grafts were applied, and in skin and bone defects complex free osteoseptocutaneous fibular, free osteoseptocutaneous radial forearm, and free skin-bone scapular flaps were used. Results. After free flap transfer 16 (14,4% revisions were performed, and after 8 unsuccessful revisions another free flaps were utilized in 3 (37,5% patients, and cross leg flaps in 5 (62,5% patients. Conclusion. The treatment of war wounds with large tissue defects by the application of free microvascular flaps

  11. Fewer Revisions in Abdominal-based Free Flaps than Latissimus Dorsi Breast Reconstruction after Radiation

    Science.gov (United States)

    Smith, Benjamin D.; Liu, Jun; Robb, Geoffrey L.; Kronowitz, Steven J.; Garvey, Patrick B.

    2016-01-01

    Background: The most commonly chosen flaps for delayed breast reconstruction after postmastectomy radiation therapy (PMRT) are abdominal-based free flaps (ABFFs) and pedicled latissimus dorsi (LD) musculocutaneous flaps. The short-and long-term advantages and disadvantages of delayed ABFFs versus LD flaps after PMRT remain unclear. We hypothesized that after PMRT, ABFFs would result in fewer postoperative complications and a lower incidence of revision surgery than LD flaps. Methods: We retrospectively reviewed a prospectively maintained database of consecutive patients who underwent unilateral, delayed breast reconstruction after PMRT using ABFFs or pedicled LD flaps with implants at the MD Anderson Cancer Center between January 1, 2001, and December 31, 2011. We compared outcomes and additional surgeries required between the 2 groups. Univariate and multivariate logistic regression modeling analyzed the relationships between patient and reconstruction characteristics and postoperative outcomes. Results: A total of 139 consecutive patients’ breast reconstructions were evaluated: 101 ABFFs (72.7%) versus 38 LDs (27.3%). Average follow-up was similar for ABFF and LD reconstructions. Although ABFF and LD reconstructions experienced similar rates of overall (30.7% vs 23.7%, respectively; P = 0.53), donor-site (8.91% vs 5.13%, respectively; P = 0.48), and flap (20.7% vs 17.9%, respectively; P = 0.37) complications, the LD reconstructions required more additional surgeries (92.1% vs 67.3%; P surgeries more than 1 year after reconstruction (37.1% vs 14.7%; P = 0.02). Conclusion: Although early complication rates were similar for both types of reconstructions, ABFFs seem to have the advantage of providing a more durable result that required fewer revision surgeries in the long term.

  12. Treatment of degloving injury involving multiple fingers with combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap.

    Science.gov (United States)

    Han, Fengshan; Wang, Guangnan; Li, Gaoshan; Ping, Juan; Mao, Zhi

    2015-01-01

    Our aim was to summarize the treatment of degloving injury involving multiple fingers using combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap. Each degloved finger was debrided under microscopic guidance and embedded in the superficial layer of the abdominal fascia. The abdominal skin was sutured to the skin on the back and side of the hand to promote circumferential healing. After removal, the only remaining injured region was on the flexor surface, and this was repaired by multiple dorsal toe flaps, toe-web flaps, and dorsalis pedis flaps to provide blood vessels and sensory nerves. All fingers had proper flap thickness 3-6 months after surgery, and required only lateral Z-plasty modification with web deepening and widening to narrow the fingers and extend their relative length. We completed flap-graft and finger narrowing for 25 fingers in eight patients. Abdominal skin flaps and dorsal toe flaps were grafted, and resulted in both firmness and softness, providing finger flexibility. The dorsal toe flap provided good blood circulation and sensory nerves, and was used to cover the finger-flexor surface to regain sensation and stability when holding objects. During the 1-8 years of follow-up, sensation on the finger-flexor side recovered to the S3-4 level, and patient satisfaction based on the Michigan Hand Outcomes Questionnaire was 4-5. Flap ulcers or bone/tendon necrosis were not observed. Treatment of degloving injury involving multiple fingers with combined abdominal superficial fascial flap, dorsalis pedis flap, dorsal toe flap, and toe-web flap was effective and reliable.

  13. Tongue musculomucosal flap for soft palate reconstruction in patients with OSAHS - clinical experience in technical strategy.

    Science.gov (United States)

    Ying, B; Ye, W; Li, Z

    2013-07-01

    With the idea of "replacing lost tissure with similar tissure in kind", vessel-pedicled palate mucosal flap, pedicled buccal musculomucosal flap and adjacent tongue musculomucosal flap could be the ideal approaches to soft palate reconstruction. To assess the adjacent tongue musculomucosal flap for soft palate reconstruction. From August 2010 to July 2011, we applied tongue musculomucosal flap for soft palate reconstruction in three patients with Obstructive Sleep Apnoea/Hypopnoes Syndrome (OSAHS) in order to release OSAHS symptom by glossal volume reduction. All patients recovered from intraoral operations with good objective as subjective speech and swallowing. Suffice it to say that OSAHS symptom was released for these patients. Here we provide a case to deal with problems related to OSAHS symptom when one works on oral surgery or reconstructing oral structure.

  14. Microvascular free flap reconstruction for head and neck cancer in a resource-constrained environment in rural India

    Directory of Open Access Journals (Sweden)

    Nirav P Trivedi

    2013-01-01

    Full Text Available Introduction: Reconstruction with free flaps has significantly changed the outcome of patients with head and neck cancer. Microsurgery is still considered a specialised procedure and is not routinely performed in the resource-constrained environment of certain developing parts of India. Materials and Methods: This article focuses on the practice environment in a cancer clinic in rural India. Availability of infrastructure, selection of the case, choice of flap, estimation of cost and complications associated with treatment are evaluated and the merits and demerits of such an approach are discussed. Results: We performed 22 cases of free flaps in a six-month period (2008-2009. Majority (17 of the patients had oral cancer. Seven were related to the tongue and eight to the buccal mucosa. Radial forearm free flap (RFF: 9 and anterolateral thigh flap (ALT: 9 were the most commonly used flaps. A fibula flap (1 was done for an anterior mandible defect, whereas a jejunum free flap (1 was done for a laryngopharyngectomy defect. There were six complications with two re-explorations but no loss of flaps. Conclusion: Reconstruction with microvascular free flaps is feasible in a resource-constrained setup with motivation and careful planning.

  15. PIV Measurements on a Blowing Flap

    Science.gov (United States)

    Hutcheson, Florence V.; Stead, Daniel J.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  16. Stability Analysis and Stabilization of T-S Fuzzy Delta Operator Systems with Time-Varying Delay via an Input-Output Approach

    Directory of Open Access Journals (Sweden)

    Zhixiong Zhong

    2013-01-01

    Full Text Available The stability analysis and stabilization of Takagi-Sugeno (T-S fuzzy delta operator systems with time-varying delay are investigated via an input-output approach. A model transformation method is employed to approximate the time-varying delay. The original system is transformed into a feedback interconnection form which has a forward subsystem with constant delays and a feedback one with uncertainties. By applying the scaled small gain (SSG theorem to deal with this new system, and based on a Lyapunov Krasovskii functional (LKF in delta operator domain, less conservative stability analysis and stabilization conditions are obtained. Numerical examples are provided to illustrate the advantages of the proposed method.

  17. Arthroscopic subtalar arthrodesis after a calcaneus fracture covered with a forearm flap.

    Science.gov (United States)

    Michels, Frederick; Stockmans, Filip; Guillo, Stéphane; Van Der Bauwhede, Jan; Oosterlinck, Dirk

    2011-01-01

    Surgical treatment of intraarticular calcaneal fractures is often associated with postoperative wound problems. Soft tissue necrosis, bone loss and uncontrollable infection are a challenge for the surgeon and amputation may in some cases be the ultimate solution. A free flap can be very helpful to cover a significant soft tissue defect and help in fighting the infection. However, the free flap complicates the surgical approach if subtalar arthrodesis and bone reconstruction are needed. This study demonstrates the value of an arthroscopic technique to resect the remaining articular cartilage in preparation for subtalar arthrodesis and bone grafting. This approach avoids compromising the soft tissues and minimizes damage to the free flap.

  18. Arthroscopic Subtalar Arthrodesis after a Calcaneus Fracture Covered with a Forearm Flap

    Directory of Open Access Journals (Sweden)

    Frederick Michels

    2011-01-01

    Full Text Available Surgical treatment of intraarticular calcaneal fractures is often associated with postoperative wound problems. Soft tissue necrosis, bone loss and uncontrollable infection are a challenge for the surgeon and amputation may in some cases be the ultimate solution. A free flap can be very helpful to cover a significant soft tissue defect and help in fighting the infection. However, the free flap complicates the surgical approach if subtalar arthrodesis and bone reconstruction are needed. This study demonstrates the value of an arthroscopic technique to resect the remaining articular cartilage in preparation for subtalar arthrodesis and bone grafting. This approach avoids compromising the soft tissues and minimizes damage to the free flap.

  19. Free digital artery flap: an ideal flap for large finger defects in situations where local flaps are precluded.

    Science.gov (United States)

    Wong, Chin-Ho; Teoh, Lam-Chuan; Lee, Jonathan Y-L; Yam, Andrew K-T; Khoo, David B-A; Yong, Fok-Chuan

    2008-03-01

    The heterodigital arterialized flap is increasingly accepted as a flap of choice for reconstruction of large finger wounds. However, in situations where the adjacent fingers sustained concomitant injuries, the use of this flap as a local flap is precluded. This paper describes our experience with the free digital artery flap as an evolution of the heterodigital arterialized flap. Four patients with large finger wounds were reconstructed with free digital artery flap. Our indications for digital artery free flap were concomitant injuries to adjacent fingers that precluded their use as donor sites. The arterial supply of the flap was from the digital artery and the venous drainage was from the dominant dorsal vein of the finger. The flap was harvested from the ulnar side of the finger. The digital nerve was left in situ to minimize donor morbidity. The donor site was covered with a full-thickness skin graft and secured with bolster dressings. Early intensive mobilization was implemented for all patients. All flaps survived. No venous congestion was noted and primary healing was achieved in all flaps. In addition to providing well-vascularized tissue for coverage of vital structures, the digital artery was also used as a flow-through flap for finger revascularization in one patient. Donor-site morbidity was minimal, with all fingers retaining protective pulp sensation and the distal and proximal interphalangeal joints retaining full ranges of motion. In conclusion, the free digital artery flap is a versatile flap that is ideal for coverage of large-sized finger defects in situations where local flaps are unavailable. Donor-site morbidity can be minimized by preservation of the digital nerve, firmly securing the skin graft with bolster dressings, and early mobilization of the donor finger.

  20. Combined posterior flap and anterior suspended flap dacryocystorhinostomy: A modification of external dacryocystorhinostomy

    Directory of Open Access Journals (Sweden)

    Amarendra Deka

    2010-01-01

    Conclusion : We believe that combined posterior flap and anterior suspended flap DCR technique is simple to perform and has the advantage of both double flap DCR and anterior suspension of anterior flaps. The results of the study showed the efficacy of this simple modification.

  1. Optimal administration routes for adipose-derived stem cells therapy in ischaemic flaps.

    Science.gov (United States)

    Lee, Dong Won; Jeon, Yeo Reum; Cho, Eul Je; Kang, Jong Hwa; Lew, Dae Hyun

    2014-08-01

    Improvement of flap survival represents an ongoing challenge in reconstructive surgery. The angiogenic potential of adipose-derived stem cells (ASCs) offers a promising approach to improve the viability of random pattern flaps. Recently, to maximize the therapeutic effects of ASCs, increasing focus is being placed on how to deliver the stem cells to target lesions. The purpose of the present study was to compare the effectiveness of different administration routes of ASCs to improve the viability of the random pattern skin flap. ASCs labelled with PKH26 were applied via four methods to the cranially-based random pattern skin flaps of rats: (a) intravenous injection; (b) subcutaneous injection; (c) application with collagen sponge seeding; and (d) application with fibrin glue seeding. ASCs led to a significant increase in flap viability in the subcutaneous injection group and the collagen sponge group. Cutaneous blood flow was increased in the intravenous injection, subcutaneous injection and collagen sponge groups. Capillary density in the intravenous injection group and collagen sponge group was significantly greater than in the control group (no treatment). PKH26-positive cells via the collagen sponge were distributed more densely within the flap than in other groups. This study demonstrated that the collagen sponge method delivered ASCs most effectively within the flap and increased flap vascularity. The clinical therapeutic effects of ASCs can therefore be maximized when the optimal delivery route is chosen.

  2. Closure of a Large Thoracolumbar Myelomeningocele Using a Modified Bilateral Keystone Flap.

    Science.gov (United States)

    Jamjoom, Hytham; Alnoman, Hatem; Almadani, Yasser

    2016-12-01

    The keystone flap, an emerging reconstructive option that can be used in many parts of the body, is gaining popularity among reconstructive surgeons. These reliable and versatile flaps can be used for large myelomeningocele closure. A modified bilateral keystone flap was used to achieve tension-free closure of a large thoracolumbar myelomeningocele associated with severe kyphosis in a newborn girl. The flap was modified by undermining in the subfascial plane in the medial aspect of the middle third. This undermining was performed to facilitate flap movement while preserving random musculocutaneous perforators captured within the island of tissues. Laterally, we approached the border of the latissimus dorsi and dissected in the submuscular plane instead of the subfascial plane to preserve more muscular fasciocutaneous perforators. We achieved soft-tissue coverage that was durable, stable, and protective. Wound healing was prompt, and the patient had a satisfactory cosmetic result. No postoperative complications were observed, such as flap necrosis, dehiscence, leakage of cerebrospinal fluid, or infection. The proposed modified keystone flap is a promising addition to the armament of reconstructive surgeons that might improve outcomes and minimize complications in myelomeningocele repair. Keystone flaps provide an ideal reconstructive option for large thoracolumbar myelomeningocele repair. They are reliable, robust, and aesthetically acceptable.

  3. Direct Yaw-Moment Control of All-Wheel-Independent-Drive Electric Vehicles with Network-Induced Delays through Parameter-Dependent Fuzzy SMC Approach

    Directory of Open Access Journals (Sweden)

    Wanke Cao

    2017-01-01

    Full Text Available This paper investigates the robust direct yaw-moment control (DYC through parameter-dependent fuzzy sliding mode control (SMC approach for all-wheel-independent-drive electric vehicles (AWID-EVs subject to network-induced delays. AWID-EVs have obvious advantages in terms of DYC over the traditional centralized-drive vehicles. However it is one of the most principal issues for AWID-EVs to ensure the robustness of DYC. Furthermore, the network-induced delays would also reduce control performance of DYC and even deteriorate the EV system. To ensure robustness of DYC and deal with network-induced delays, a parameter-dependent fuzzy sliding mode control (FSMC method based on the real-time information of vehicle states and delays is proposed in this paper. The results of cosimulations with Simulink® and CarSim® demonstrate the effectiveness of the proposed controller. Moreover, the results of comparison with a conventional FSMC controller illustrate the strength of explicitly dealing with network-induced delays.

  4. An LMI Approach to H∞ Performance Analysis of Continous-Time System with Two Additive Time-Varying Delays

    Directory of Open Access Journals (Sweden)

    Wrastawa Ridwan

    2011-08-01

    Full Text Available This paper investigates the problem of H∞ performance analysis for continous–time systems with two additive time-varying delays in the state. Our objective is focused on stability analysis of a continuous system with two time-varying delays with an H∞ disturbance attenuation level γ. By exploiting Lyapunov-Krasovski functional and introducing free weighting matrix variables, LMI stability condition have been derived.

  5. Internal Mammary Recipient Site Breast Cancer Recurrence Following Delayed Microvascular Breast Reconstruction

    OpenAIRE

    Rosich-Medina, Anais; Wang, Susan; Erel, Ertan; Malata, Charles M.

    2013-01-01

    Objective: The internal mammary vessels are a popular recipient site for microsurgical anastomoses of free flap breast reconstructions. We, however, observed 3 patients undergoing internal mammary vessel delayed free flap breast reconstruction that subsequently developed tumor recurrence at this site. We reviewed their characteristics to determine whether there was a correlation between delayed microsurgical reconstruction and local recurrence. Methods: A retrospective review of a single surg...

  6. Comparison of outcomes of pressure sore reconstructions among perforator flaps, perforator-based rotation fasciocutaneous flaps, and musculocutaneous flaps.

    Science.gov (United States)

    Kuo, Pao-Jen; Chew, Khong-Yik; Kuo, Yur-Ren; Lin, Pao-Yuan

    2014-10-01

    Pressure sore reconstruction remains a significant challenge for plastic surgeons due to its high postoperative complication and recurrence rates. Free-style perforator flap, fasciocutaeous flap, and musculocutaneous flap are the most common options in pressure sore reconstructions. Our study compared the postoperative complications among these three flaps at Kaohsiung Chang Gung Memorial Hospital. From 2003 to 2012, 99 patients (54 men and 45 women) with grade III or IV pressure sores received regional flap reconstruction, consisting of three cohorts: group A, 35 free-style perforator-based flaps; group B, 37 gluteal rotation fasciocutaneous flaps; and group C, 27 musculocutaneous or muscle combined with fasciocutaneous flap. Wound complications such as wound infection, dehiscence, seroma formation of the donor site, partial or complete flap loss, and recurrence were reviewed. The mean follow-up period for group A was 24.2 months, 20.8 months in group B, and 19.0 months for group C. The overall complication rate was 22.9%, 32.4%, and 22.2% in groups A, B, and C, respectively. The flap necrosis rate was 11.4%, 13.5%, and 0% in groups A, B, and C, respectively. There was no statistical significance regarding complication rate and flap necrosis rate among different groups. In our study, the differences of complication rates and flap necrosis rate between these groups were not statistically significant. Further investigations should be conducted. © 2014 Wiley Periodicals, Inc.

  7. Traumatic Forefoot Reconstructions With Free Perforator Flaps.

    Science.gov (United States)

    Zhu, Yue-Liang; He, Xiao-Qing; Wang, Yi; Lv, Qian; Fan, Xin-Yv; Xu, Yong-Qing

    2015-01-01

    The forefoot is critical to normal walking; thus, any reconstruction of forefoot defects, including the soft tissues, must be carefully done. The free perforator flap, with its physiologic circulation, lower donor site morbidity, and minimal thickness is the most popular technique in plastic and microsurgery, and is theoretically the most suitable for such forefoot reconstruction. However, these flaps are generally recognized as more difficult and time-consuming to create than other flaps. In 41 patients with traumatic forefoot defects, we reconstructed the forefoot integument using 5 types of free perforator flaps. The overall functional and cosmetic outcomes were excellent. Three flaps required repeat exploration; one survived. The most common complications were insufficient perfusion and the need for second debulking. The key to our success was thoroughly debriding devitalized bone and soft tissue before attaching the flap. Forefoot reconstruction with a free perforator flap provides better function, better cosmesis, better weightbearing, and better gait than the other flaps we have used.

  8. [Development and current status of perforator flaps].

    Science.gov (United States)

    Xu, Dachuan; Zhang, Shimin; Tang, Maolin; Ouyang, Jun

    2011-09-01

    To provide a comprehensive review for development and existing problems of the perforator flaps. The related home and abroad literature concerning perforator flaps was extensively reviewed. The perforator flaps are defined as the axial flaps nourished solely by small cutaneous perforating vessels (perforating arteries and veins), which are exclusively composed of skin and subcutaneous fat. The perforator flaps have the advantages as follows: less injury at donor site, less damage to the contour of the donor site, good reconstruction and appearance of the recipient site flexible design, and short time of postoperative recovery, which have been widely used in reconstructive surgery. The perforator flaps are the new development of the microsurgery, which usher an era of small axial flaps; However, the controversies of the definition, vascular classification, the nomenclature, and the clinical application of the perforator flaps still exist, which are therefore the hot spot for future study.

  9. Head and neck reconstruction using infrahyoid myocutaneous flaps

    Directory of Open Access Journals (Sweden)

    Alfio José Tincani

    Full Text Available CONTEXT AND OBJECTIVE: The use of pedicled myocutaneous flaps in head and neck reconstruction is widely accepted. Here we describe our experience with infrahyoid flaps (IHFs employed to cover surgical defects in the oral cavity and oropharynx in patients with benign and malignant tumors. The aim was to evaluate the success rate for infrahyoid myocutaneous flap procedures performed at a single institution. DESIGN AND SETTING: Retrospective study, at the Head and Neck Surgery Service, Unicamp. METHODS: Fourteen IHFs were used to reconstruct surgical defects in eleven men (78.5% and three women (21.5% with a mean age of 66.4 years. The anterior floor of the mouth was reconstructed in nine patients (64.2%, the base of tongue in three (21.4%, the lateral floor in one (7.1%, and the retromolar area (7.1% in one. Thirteen patients (92.8% had squamous cell carcinoma (SCC and one (7.2% ameloblastoma. The disease stage was T3 in eight (61.5% of the SCC cases and T4 in five (38.5%. RESULTS: No patient presented total flap loss or fistula. The most common complication was epidermolysis, which delayed the beginning of oral ingestion. The patients with SCC received postoperative radiotherapy without major consequences to the flap. CONCLUSION: IHF is a safe and reliable procedure for reconstructing head and neck surgical defects. Due to its thinness and malleability, its use for oral cavity and oropharynx defects provides favorable cosmetic and functional outcomes. Complications, when present, are easy to manage.

  10. Autologous breast reconstruction with endoscopic latissimus dorsi musculosubcutaneous flaps in patients choosing breast-conserving therapy: mammographic appearance.

    Science.gov (United States)

    Monticciolo, D L; Ross, D; Bostwick, J; Eaves, F; Styblo, T

    1996-08-01

    The objective of this study was to define and evaluate mammographic changes in patients treated with breast-conserving therapy and a new reconstructive technique that uses autologous tissue from a latissimus dorsi musculosubcutaneous flap. Of 20 patients who underwent either immediate or delayed endoscopic latissimus dorsi muscle flap reconstruction after lumpectomy, 13 also had postsurgery mammograms available for review. Radiographic findings assessed included skin thickening, density or radiolucency at the reconstruction site, density around the flap, fat necrosis, calcifications, and the presence of surgical clips. Mammograms for three patients (23%) revealed thickening that we believed was attributable to radiation therapy. No patient had increased density in the flap itself; all flaps were relatively radiolucent centrally (13/13; 100%). Mammograms revealed density around the rim of the flap in four patients (31%). This density was most likely secondary to latissimus dorsi muscle fibers and did not limit radiographic evaluation. One patient had calcifications, probably secondary to fat necrosis. No oil cysts were seen. In the majority of patients (11/13; 85%), surgical clips were visible. Endoscopic latissimus dorsi muscle flap reconstruction, previously used only for mastectomy patients, is now being used for improved esthetic outcome in selected patients who desire breast conservation. Our results indicate that the mammographic findings are predictable. The most common findings are relative radiolucency centrally, with or without density from muscle fibers around the edges of the area of tissue transfer. The transplanted musculosubcutaneous flap does not interfere with mammographic evaluation.

  11. Fibular flap for mandible reconstruction in osteoradionecrosis of the jaw: selection criteria of fibula flap

    OpenAIRE

    Kim, Ji-Wan; Hwang, Jong-Hyun; Ahn, Kang-Min

    2016-01-01

    Background Osteoradionecrosis is the most dreadful complication after head and neck irradiation. Orocutaneous fistula makes patients difficult to eat food. Fibular free flap is the choice of the flap for mandibular reconstruction. Osteocutaneous flap can reconstruct both hard and soft tissues simultaneously. This study was to investigate the success rate and results of the free fibular flap for osteoradionecrosis of the mandible and which side of the flap should be harvested for better recons...

  12. Flapping wing micro-aerial-vehicle:Kinematics, membranes, and flapping mechanisms of ornithopter and insect flight

    Institute of Scientific and Technical Information of China (English)

    Mohd Firdaus Bin Abas; Azmin Shakrine Bin Mohd Rafie; Hamid Bin Yusoff; Kamarul Arifin Bin Ahmad

    2016-01-01

    The application of biomimetics in the development of unmanned-aerial-vehicles (UAV) has advanced to an exceptionally small scale of nano-aerial-vehicles (NAV), which has surpassed its immediate predecessor of micro-aerial-vehicles (MAV), leaving a vast range of development possi-bilities that MAVs have to offer. Because of the prompt advancement into the NAV research devel-opment, the true potential and challenges presented by MAV development were never solved, understood, and truly uncovered, especially under the influence of transition and low Reynolds number flow characteristics. This paper reviews a part of previous MAV research developments which are deemed important of notification; kinematics, membranes, and flapping mechanisms ranges from small birds to big insects, which resides within the transition and low Reynolds number regimes. This paper also reviews the possibility of applying a piezoelectric transmission used to pro-duce NAV flapping wing motion and mounted on a MAV, replacing the conventional motorized flapping wing transmission. Findings suggest that limited work has been done for MAVs matching these criteria. The preferred research approach has seen bias towards numerical analysis as com-pared to experimental analysis.

  13. Flapping wing micro-aerial-vehicle: Kinematics, membranes, and flapping mechanisms of ornithopter and insect flight

    Directory of Open Access Journals (Sweden)

    Mohd Firdaus Bin Abas

    2016-10-01

    Full Text Available The application of biomimetics in the development of unmanned-aerial-vehicles (UAV has advanced to an exceptionally small scale of nano-aerial-vehicles (NAV, which has surpassed its immediate predecessor of micro-aerial-vehicles (MAV, leaving a vast range of development possibilities that MAVs have to offer. Because of the prompt advancement into the NAV research development, the true potential and challenges presented by MAV development were never solved, understood, and truly uncovered, especially under the influence of transition and low Reynolds number flow characteristics. This paper reviews a part of previous MAV research developments which are deemed important of notification; kinematics, membranes, and flapping mechanisms ranges from small birds to big insects, which resides within the transition and low Reynolds number regimes. This paper also reviews the possibility of applying a piezoelectric transmission used to produce NAV flapping wing motion and mounted on a MAV, replacing the conventional motorized flapping wing transmission. Findings suggest that limited work has been done for MAVs matching these criteria. The preferred research approach has seen bias towards numerical analysis as compared to experimental analysis.

  14. Experience of an integ rated approach to the rehabilitation of athletes with delayed fracture unions of long bones.

    Directory of Open Access Journals (Sweden)

    Kotenko K.V.

    2014-12-01

    Full Text Available Aim. The authors have developed a comprehensive rehabilitation program promotes the formation of a full-fledged callus after fractures of the lower limbs. Objective: To evaluate the effectiveness of inclusion developed a comprehensive program of rehabilitation in patients with delayed consolidation of long bones. Material and Methods: The study included 10 patients with a diagnosis of fracture in the lower extremity with delayed. Results: Under the influence of a rehabilitation program that includes exercise therapy to individually develop a complex, hydrokinesitherapy, practice on robotic biomechanical complex "KonTreks" exercise on a bicycle ergometer, physiotherapy, was marked by the increase of power and functional parameters of joint and muscular legs. Conclusion: The application of the developed program of rehabilitation treatment of patients with a diagnosis of a fracture in the lower extremities with delayed consolidation is highly effective and pathogenetically substantiated by affecting the speed-strength and power performance of muscles of the lower extremities.

  15. Augmented Lyapunov approach to H∞ state estimation of static neural networks with discrete and distributed time-varying delays

    Science.gov (United States)

    Syed, Ali M.; Saravanakumar, R.

    2015-05-01

    This paper deals with H∞ state estimation problem of neural networks with discrete and distributed time-varying delays. A novel delay-dependent concept of H∞ state estimation is proposed to estimate the H∞ performance and global asymptotic stability of the concerned neural networks. By constructing the Lyapunov-Krasovskii functional and using the linear matrix inequality technique, sufficient conditions for delay-dependent H∞ performances are obtained, which can be easily solved by some standard numerical algorithms. Finally, numerical examples are given to illustrate the usefulness and effectiveness of the proposed theoretical results. Project supported by the Fund from National Board of Higher Mathematics (NBHM), New Delhi (Grant No. 2/48/10/2011-R&D-II/865).

  16. A case report of total breast reconstruction using an inframammary adipofascial flap with an implant.

    Science.gov (United States)

    Ogawa, Tomoko; Yamakawa, Tomomi

    2016-01-01

    Prosthetic-based breast reconstruction can be used in combination with autologous flaps such as a latissimus dorsi (LD) flap or a thoracodorsal artery perforator (TDAP) flap to achieve symmetry. However, the LD and TDAP flaps require a different skin incision from that which is used for the mastectomy. As a new autologous flap for use in combination with prosthetic-based breast reconstruction after nipple-sparing mastectomy (NSM), we used an inframammary adipofascial flap. The patient was a 27-year-old female with moderate ptotic breasts, who had ductal carcinoma in situ in the lower outer quadrant of her left breast. After NSM through the inframammary fold (IMF) incision, the subcutaneous fat of the intended inframammary area was undermined, and the tongue shaped adipofascial flap was pulled up in the intended area. After inserting a tissue expander under the major pectoral muscle, this adipofascial flap was reflected back to the inferior portion of the breast area. After modeling the breast mound with this flap, the inframammary skin incision was sutured. Eleven months later, the patient underwent surgery to replace the expander with a permanent implant. Eight months after the replacement with an implant, the cosmetic result is good. This procedure can be performed through the same skin incision on the IMF as NSM. Total breast reconstruction using the inframammary adipofascial flap with an implant can be an alternative approach to achieving symmetry in some patients. This method is useful for breast reconstruction after NSM for young patients with moderate-ptotic breasts. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

  17. Effects of leading and trailing edge flaps on the aerodynamics of airfoil/vortex interactions

    Science.gov (United States)

    Hassan, Ahmed A.; Sankar, L. N.; Tadghighi, H.

    1994-01-01

    A numerical procedure has been developed for predicting the two-dimensional parallel interaction between a free convecting vortex and a NACA 0012 airfoil having leading and trailing edge integral-type flaps. Special emphasis is placed on the unsteady flap motion effects which result in alleviating the interaction at subcritical and supercritical onset flows. The numerical procedure described here is based on the implicit finite-difference solutions to the unsteady two-dimensional full potential equation. Vortex-induced effects are computed using the Biot-Savart Law with allowance for a finite core radius. The vortex-induced velocities at the surface of the airfoil are incorporated into the potential flow model via the use of the velocity transpiration approach. Flap motion effects are also modeled using the transpiration approach. For subcritical interactions, our results indicate that trailing edge flaps can be used to alleviate the impulsive loads experienced by the airfoil. For supercritical interactions, our results demonstrate the necessity of using a leading edge flap, rather than a trailing edge flap, to alleviate the interaction. Results for various time-dependent flap motions and their effect on the predicted temporal sectional loads, differential pressures, and the free vortex trajectories are presented

  18. Second Toe Plantar Free Flap for Volar Tissue Defects of the Fingers

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    Yong Jin Cho

    2013-05-01

    Full Text Available BackgroundThe reconstruction of volar surface defects is difficult because of the special histologic nature of the tissue involved. The plantar surface is the most homologous in shape and function and could be considered the most ideal of reconstructive options in select cases of volar surface defects. In this paper, we evaluate a single institutional case series of volar tissue defects managed with second toe plantar free flaps.MethodsA single-institution retrospective review was performed on 12 cases of reconstruction using a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years with a male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 cases followed by amputations (3 cases and a single case of burn injury. Half of the indications (6 cases were for soft-tissue defects with the other half for scar contracture.ResultsAll of the flaps survived through the follow-up period. Sensory recovery was related to the time interval between injury and reconstruction-with delayed operations portending worse outcomes. There were no postoperative complications in this series.ConclusionsFlexion contracture is the key functional deficit of volar tissue defects. The second toe plantar free flap is the singular flap whose histology most closely matches those of the original volar tissue. In our experience, this flap is the superior reconstructive option within the specific indications dictated by the defect size and location.

  19. Possibility of management of lower leg war burns with free flaps

    Directory of Open Access Journals (Sweden)

    Panajotović Ljubomir

    2003-01-01

    Full Text Available Free flaps are used in the surgical treatment of burns for wound closure where the burn is too deep, and in case, when after necrotic tissue excision, the bones, tendons, nerves, and blood vessels remain bare. Covering of the exposed structures is commonly performed in the primary delayed, or in the secondary wound treatment. The possibilities of covering the defects of the lower leg with local flaps are limited. Free flaps are used when all the possibilities of the other reconstructive procedures have been exhausted. The defect of the soft tissue of the lower leg was covered with free flaps in the injured soldiers with deep burns, treated at the Clinic for Plastic Surgery and Burns, Military Medical Academy, Belgrade. In one patient the wound closing was performed immediately after excision of necrotic tissues, and in the other two in the secondary management. The application of free microvascular flaps enabled the closure of large post excision defects of the lower leg in one operation. Our experience in the treatment of these soldiers point to the possibility of coverage of the exposed deep structures with free flaps as early as possible.

  20. Experiences and lessons about soft-tissue flaps covering of severe open tibial fracture

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Objective: To sum up experiences and lessons about management of soft-tissue reconstruction in open tibial fracture over a 6-year period.Methods: Twenty-two flap reconstructions were performed to treat soft-tissue defect of 22 patients with open tibial fracture Type IIIB (Gustilo) from 1993 to 1998. The cases were analyzed and discussed retrospectively after follow up of 12-61 months.Results: The size of the flap ranged from 6.6 cm2 to 28.18 cm2 and the rate of flap failure was 13.6%. Besides, 3 partial necrosis and 2 postoperative infections occurred in this series.Conclusions: For soft tissuedefect of delayed open tibial fracture Type HIB, flap reconstruction is still an optimal option. The experiences we obtained are ① to design a triangular skin extension or a small Z-plasty over the pedicle to reduce the flap tension; ② to select a unilateral external fixation to provide convenience for anysecondary manipulation; and ③ to use serial debridementto diminish flap failure. de

  1. commensurate point delays

    Directory of Open Access Journals (Sweden)

    M. de la Sen

    2005-01-01

    nominal controller is maintained. In the current approach, the finite spectrum assignment is only considered as a particular case of the designer's choice of a (delay-dependent arbitrary spectrum assignment objective.

  2. Predictors of Proximal Interphalangeal Joint Flexion Contracture After Homodigital Island Flap.

    Science.gov (United States)

    Nakanishi, Akito; Omokawa, Shohei; Iida, Akio; Kaji, Daisuke; Tanaka, Yasuhito

    2015-11-01

    To identify independent predictors of postoperative proximal interphalangeal (PIP) joint contracture after direct-flow homodigital island flap transfer. Forty-four fingertip amputations in 39 patients treated with oblique triangular flaps were evaluated at a minimum of 1 year after surgery. Five variables were examined: patient age, injured finger, mechanism of injury, flap advancement distance, and time required for wound healing. Univariate and multivariate linear regression analyses were performed to identify the extent to which these variables affected the flexion contracture of the PIP joint. The average reduction in the passive extension angle of the PIP joint was 16° at final follow-up. Univariate analysis indicated significant correlations of PIP joint flexion contracture with age, injured finger, and time for wound healing, but no significant correlation with the distance the flap was advanced. Multivariate analysis indicated that the age and duration of wound healing were independent predictors of the flexion contracture of the PIP joint. Elderly people and cases with delayed wound healing are at risk for postoperative PIP joint contracture after homodigital flap transfer. Intervention with early hand therapy and orthotics may be useful in elderly patients with delayed wound healing. Prognostic II. Copyright © 2015 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  3. Salvage of Failed Local and Regional Flaps with Porcine Urinary Bladder Extracellular Matrix Aided Tissue Regeneration

    Directory of Open Access Journals (Sweden)

    Gregory J. Kruper

    2013-01-01

    Full Text Available Local and regional flap failure can be a major complication in head and neck surgery, which continue to be prevalent for a number of reasons including poor flap design, improper surgical technique, and poor tissue vascularity. Dealing with these failures can be quite difficult. Surgical debridement, flap revisions, and complex wound regimens are necessitated to reestablish appropriate tissue coverage. Traditional use of wet to dry dressing to enable proper wound granulation and possible closure with additional flaps or skin grafts is a laborious process. Such treatments place great time burdens on the patient, physicians, and nurses. Because the face and neck possess a complex three-dimensional topography, wound dressings are inherently complex to design and change. Many patients also require postoperative treatments such as radiation and chemotherapy to treat aggressive malignancies, and delay in wound healing leads to a delay in adjuvant treatment. Recently, advances in regenerative medicine, specifically xenogeneic extracellular matrix compounds, have been shown to promote tissue growth while limiting scar tissue formation (Badylak 2004. To our knowledge, this paper is the first case series using the porcine extracellular matrix bioscaffold (MatriStem ACell, Columbia, MD, USA to salvage flaps with extensive wound breakdown on the face and neck.

  4. Management of Implant Exposure in One-Stage Breast Reconstruction Using Titanium-Coated Polypropylene Mesh: Sub-Mammary Intercostal Perforator Flap.

    Science.gov (United States)

    De Riggi, Michele Antonio; Rocco, Nicola; Gherardini, Giulio; Esposito, Emanuela; D'Aiuto, Massimiliano

    2016-12-01

    One-stage implant-based breast reconstruction using titanium-coated polypropylene mesh is a novel approach widely used in Europe. Complication rates in breast reconstruction with the use of titanium-coated meshes seem to be comparable to those in patients with implant-based breast reconstruction alone. However, the use of synthetic meshes in implant-based breast reconstructive surgery leads to new clinical scenarios with the need for the breast surgeon to face new complications. We present an innovative treatment of implant exposure in the absence of infection in patients who underwent nipple-sparing mastectomy and immediate breast reconstruction with silicone implants and titanium-coated polypropylene mesh by using a pedicled sub-mammary intercostal perforator flap. Four patients who experienced implant exposure without infection have been treated with the use of a sub-mammary intercostal perforator flap. Whole coverage of the exposed implant/mesh with a sub-mammary intercostal perforator flap was obtained in all cases. No post-operative complications have been observed, whereas a pleasant aesthetic result has been achieved. Patients' post-operative quality of life and satisfaction levels were measured by the European Organisation for Research and Treatment of Cancer breast cancer-specific quality of life QLQ-BR23 questionnaire and showed an average good satisfaction with the post-operative outcomes (mean QLQ-BR23 score 1.9). For the first time, a sub-mammary intercostal perforator flap has been used with the aim of treating implant exposures without removing the prosthesis even in the presence of synthetic meshes, when wound infection was excluded. Although tested on a small series, the sub-mammary intercostal perforator flap might represent a simple, versatile and cost-effective procedure for the management of implant exposure following nipple-sparing mastectomy and immediate reconstruction with silicone implants and synthetic meshes. It should be considered to

  5. The Semimartingale Approach to Almost Sure Stability Analysis of a Two-Stage Numerical Method for Stochastic Delay Differential Equation

    Directory of Open Access Journals (Sweden)

    Qian Guo

    2014-01-01

    Full Text Available Almost sure exponential stability of the split-step backward Euler (SSBE method applied to an Itô-type stochastic differential equation with time-varying delay is discussed by the techniques based on Doob-Mayer decomposition and semimartingale convergence theorem. Numerical experiments confirm the theoretical analysis.

  6. [Functional hemitongue reconstruction with free forearm flap].

    Science.gov (United States)

    Liao, Gui-Qing; Su, Yu-Xiong; Liu, Hai-Chao; Li, Jin; Fahmha, Numan; Ou, De-Ming; Wang, Qin

    2008-07-01

    To investigate the clinical application of free forearm flap in the functional hemitongue reconstruction. From July 2002 to November 2006, 40 patients with tongue cancer underwent hemiglossectomy and primary hemitongue reconstruction with free forearm flaps. In some cases, the lateral antebrachial cutaneous nerves of the flaps were anastomosed with the lingual nerve to restore the flap sensation. All patients recovered uneventfully after surgery with no morbidity in the donor site. All free flaps survived. The average follow-up period was 2 years and 6 months. The aesthetic and functional results were both satisfactory. The swallowing and speech function were almost normal. The flap sensation was partially restored. Good functional hemitongue reconstruction can be achieved with free forearm flaps.

  7. Flap tear of rectus muscles: an underlying cause of strabismus after orbital trauma.

    Science.gov (United States)

    Ludwig, Irene H; Brown, Mark S

    2002-11-01

    To present an avulsion injury of the rectus muscle after orbital trauma, usually the inferior rectus, and detail its diagnosis and operative repair. Forty-three patients underwent repair of flap tears of 62 rectus muscles. During surgery, we found the muscle abnormality was often subtle, with narrowing or thinning of the remaining attached global layer of muscle. The detached flap of external (orbital) muscle was found embedded in surrounding orbital fat and connective tissue. Retrieval and repair were performed in each case. The causes of orbital trauma were as follows: orbital fractures (15 patients), blunt trauma with no fracture (11 patients), suspected trauma but did not undergo computerized tomographic scan (12 patients), and status after retinal detachment repair (5 patients). Of note, 15 of the 43 patients (35%) underwent repair of the flap tear alone, without any additional orbital or strabismus surgery. Diagnostically, the predominant motility defect in 45 muscles was limitation toward the field of action of the muscle, presumably as a result of a tether created by the torn flap; these tethers simulated muscle palsy. Seventeen muscles were restricted away from their field of action, simulating entrapment. The direction taken by the flap during healing determined the resultant strabismus pattern. All patients with gaze limitation toward an orbital fracture had flap tears. The worst results after flap tear repair were seen in patients (1) who had undergone orbital fracture repair before presentation, (2) who had undergone previous attempts at strabismus repair, and (3) who had the longest intervals between the precipitating event and the repair. The best results were obtained in patients who underwent simultaneous fracture and strabismus repair or early strabismus repair alone. Avulsion-type flap tears of the extraocular muscles are a common cause of posttraumatic strabismus. Early repair produces the best results, but improvement is possible despite long

  8. Retrospective study of reverse dorsal metacarpal flap and compound flap: a review of 122 cases

    Institute of Scientific and Technical Information of China (English)

    LU Lai-jin; GONG Xu; LIU Zhi-gang; ZHANG Zhi-xin

    2006-01-01

    Objective:To evaluate the clinical application and discuss the operative indication of the reverse dorsal metacarpal flap and its compound flap on the skin defects of hand.Methods: From 1990 to 2003, we applied the reverse dorsal metacarpal flap and its compound flap to repair soft tissue defects of fingers in 122 cases, which included 90cases of the reverse metacarpal flap and 32 cases of its compound flaps with tendon grafts, nerve grafts or bone grafts. Based on the follow-up observations, we analyzed the indications of the reverse metacarpal flap and its compound flaps, the postoperative contours, flap colors and textures in comparison to contralateral fingers retrospectively.Results: In the series of 122 cases, flaps survived and the donor site defects were closed directly. The follow-up period ranged from 1-12 years. The postoperative contours,colors and textures of the flaps and its compound flaps were similar to those of normal fingers, although linear scar remained. According to standards of sense recovery(British Medical Research Council, BMRC ), the sense function of the flaps resumed S3 after operation for 1 year.In 10 cases with the tendon defects treated by the flap with tendon grafts, function of flexion-extension of fingers resumed 50%-75% in comparison to the contralateral fingers using the method of measurement of total active motion. In 7 cases with the phalangeal nonunion or bone defects treated by the flap with bone grafts, union occurred after operation for 3 months.Conclusions: To soft tissue defects on fingers with bone or tendon exposure, the reverse metacarpal flap and its compound flap are a better choice for repairing. The range of repairing is up to the distal interphalangeal joint of fingers. The second dorsal metacarpal artery is more consistent and larger as the choice of vascular pedicle, in comparison with other dorsal metacarpal arteries.Postoperative flap color and texture are similar to normal fingers.

  9. Internal Mammary Artery Perforator flap

    NARCIS (Netherlands)

    Schellekens, P.P.A.

    2012-01-01

    Reconstructive surgery evolved as a result of the enormous numbers of World War I and II victims, long before profound knowledge of the vascularity of flaps was present. Sophisticated imaging techniques have given us at present a thorough understanding of the vascularity of tissues so that randomly

  10. Sternocleidomastoid Muscle Flap after Parotidectomy.

    Science.gov (United States)

    Nofal, Ahmad Abdel-Fattah; Mohamed, Morsi

    2015-10-01

    Introduction Most patients after either superficial or total parotidectomy develop facial deformity and Frey syndrome, which leads to a significant degree of patient dissatisfaction. Objective Assess the functional outcome and esthetic results of the superiorly based sternocleidomastoid muscle (SCM) flap after superficial or total parotidectomy. Methods A prospective cohort study for 11 patients subjected to parotidectomy using a partial-thickness superiorly based SCM flap. The functional outcome (Frey syndrome, facial nerve involvement, and ear lobule sensation) and the esthetic results were evaluated subjectively and objectively. Results Facial nerve palsy occurred in 5 cases (45%), and all of them recovered completely within 6 months. The Minor starch iodine test was positive in 3 patients (27%), although only 1 (9%) subjectively complained of gustatory sweating. The designed visual analog score completed by the patients themselves ranged from 0 to 3 with a mean of 1.55 ± 0.93; the scores from the blinded evaluators ranged from 1 to 3 with a mean 1.64 ± 0.67. Conclusion The partial-thickness superiorly based SCM flap offers a reasonable cosmetic option for reconstruction following either superficial or total parotidectomy by improving the facial deformity. The flap also lowers the incidence of Frey syndrome objectively and subjectively with no reported hazard of the spinal accessory nerve.

  11. Sternocleidomastoid Muscle Flap after Parotidectomy

    Directory of Open Access Journals (Sweden)

    Nofal, Ahmad Abdel-Fattah

    2015-04-01

    Full Text Available Introduction Most patients after either superficial or total parotidectomy develop facial deformity and Frey syndrome, which leads to a significant degree of patient dissatisfaction. Objective Assess the functional outcome and esthetic results of the superiorly based sternocleidomastoid muscle (SCM flap after superficial or total parotidectomy. Methods A prospective cohort study for 11 patients subjected to parotidectomy using a partial-thickness superiorly based SCM flap. The functional outcome (Frey syndrome, facial nerve involvement, and ear lobule sensation and the esthetic results were evaluated subjectively and objectively. Results Facial nerve palsy occurred in 5 cases (45%, and all of them recovered completely within 6 months. The Minor starch iodine test was positive in 3 patients (27%, although only 1 (9% subjectively complained of gustatory sweating. The designed visual analog score completed by the patients themselves ranged from 0 to 3 with a mean of 1.55 ± 0.93; the scores from the blinded evaluators ranged from 1 to 3 with a mean 1.64 ± 0.67. Conclusion The partial-thickness superiorly based SCM flap offers a reasonable cosmetic option for reconstruction following either superficial or total parotidectomy by improving the facial deformity. The flap also lowers the incidence of Frey syndrome objectively and subjectively with no reported hazard of the spinal accessory nerve.

  12. The freestyle pedicle perforator flap

    DEFF Research Database (Denmark)

    Gunnarsson, Gudjon Leifur; Jackson, Ian T; Westvik, Tormod S;

    2015-01-01

    not widely performed by the general plastic surgeons. The aim of this paper is to present the simplicity of pedicled perforator flap reconstruction of moderate-sized defects of the extremities and torso. METHODS: We retrospectively reviewed the charts of 34 patients reconstructed using 34 freestyle pedicled...

  13. The possibility for use of venous flaps in plastic surgery

    Energy Technology Data Exchange (ETDEWEB)

    Baytinger, V. F., E-mail: baitinger@mail.tomsknet.ru; Kurochkina, O. S., E-mail: kurochkinaos@yandex.ru; Selianinov, K. V.; Baytinger, A. V. [Research Institute of Microsurgery, Tomsk (Russian Federation); Dzyuman, A. N. [Siberian State Medical University, Tomsk (Russian Federation)

    2015-11-17

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  14. The possibility for use of venous flaps in plastic surgery

    Science.gov (United States)

    Baytinger, V. F.; Kurochkina, O. S.; Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    2015-11-01

    The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were no differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.

  15. First dorsal metacarpal artery flap for thumb reconstruction: a retrospective clinical study

    Science.gov (United States)

    Muyldermans, Thomas

    2009-01-01

    Extensive pulp (zone 4) defects of the thumb, with the exposure of tendon or bone, are challenging reconstructive problems. Surgical treatment includes the use of local, regional, and free flaps. The first dorsal metacarpal artery flap has been used successfully for defects of the thumb. The innerved first dorsal metacarpal artery flap from the dorsum of the index finger was first described by Hilgenfeldt and refined by Holevich. An island flap carried on a neurovascular pedicle consisting of the first dorsal metacarpal artery was first demonstrated by Foucher and Braun. Seven innervated FDMCA island flaps were performed from May 2005 until July 2007 for thumb reconstruction. There were three women and four men with an average age of 54.9 years (range 28–89 years). The mean follow-up period was 15.4 months (range 4–29 months). The dominant hand was involved in six (85.7%) patients. In a retrospective clinical study, the following criteria were evaluated: (1) etiology of the defect, (2) time of reconstruction (primary vs. delayed), (3) survival rate of flap, (4) sensory function (Semmes–Weinstein monofilaments, static 2-PD, pain, cortical reorientation), (5) TAM measured with the Kapandji index, and (6) subjective patient satisfaction (SF 36). Four patients presented with trauma, two patients with defects after tumor resection and one with infection of the thumb. The flap was used for immediate reconstruction in three (42.9%) patients and for delayed reconstruction in four (57.1%) patients. Delayed reconstruction was performed 4.75 (1–12) months after initial trauma or first surgery. The donor area was grafted with full-thickness skin grafts in all cases. All flaps survived. The mean SWMF was 3.31 g and average statis 2-PD over the flap was 10.57 mm. Pain at the flap scored 3.71 over 10 and at the donor site 2.17 over 10. Paresthesia at the flap scored 0.57 over 4 and at the donor site 0.33 over 4. Complete cortical reorientation was only seen in one

  16. Robust Output Feedback Control for Active Seat Suspension Systems with Actuator Time Delay Using µ-Synthesis Approach

    Directory of Open Access Journals (Sweden)

    Mohammad Gudarzi

    2013-10-01

    Full Text Available This study presents a robust output feedback optimal H&infin control synthesis for a class of uncertain seat suspension systems with actuator saturation and an uncertain actuator time delay. A vertical vibration model of human body is added in order to make the modeling of seat suspension systems more accurate. A dynamic controller is considered by using of two measurable states of the model, by real sensors, as output feedback. Moreover, uncertain actuator time delay is considered to guarantee robust performance of the closed-loop system. The controller is derived by using D-K iteration algorithm for constrained systems with norm-bounded uncertainties. The corresponding closed-loop system is asymptotically stable with a guaranteed H&infin performance. Finally, a design example is presented to show the performance and robustness of the developed theoretical results.

  17. Linear matrix inequality approach to exponential synchronization of a class of chaotic neural networks with time-varying delays

    Institute of Scientific and Technical Information of China (English)

    Wu Wei; Cui Bao-Tong

    2007-01-01

    In this paper, a synchronization scheme for a class of chaotic neural networks with time-varying delays is presented.This class of chaotic neural networks covers several well-known neural network, such a Hopfield neural networks, cellular neural networks, and bidirectional associative memory networks. The obtained criteria are expressed in terms of linear matrix inequalities, thus they can be efficiently verified. A comparison between our results and the previous results shows that our results are less restrictive.

  18. A Game-Theoretic Approach to Energy-Efficient Modulation in CDMA Networks with Delay QoS Constraints

    CERN Document Server

    Meshkati, Farhad; Poor, H Vincent; Schwartz, Stuart C

    2007-01-01

    A game-theoretic framework is used to study the effect of constellation size on the energy efficiency of wireless networks for M-QAM modulation. A non-cooperative game is proposed in which each user seeks to choose its transmit power (and possibly transmit symbol rate) as well as the constellation size in order to maximize its own utility while satisfying its delay quality-of-service (QoS) constraint. The utility function used here measures the number of reliable bits transmitted per joule of energy consumed, and is particularly suitable for energy-constrained networks. The best-response strategies and Nash equilibrium solution for the proposed game are derived. It is shown that in order to maximize its utility (in bits per joule), a user must choose the lowest constellation size that can accommodate the user's delay constraint. This strategy is different from one that would maximize spectral efficiency. Using this framework, the tradeoffs among energy efficiency, delay, throughput and constellation size are ...

  19. Delayed Puberty

    DEFF Research Database (Denmark)

    Kolby, Nanna; Busch, Alexander Siegfried; Juul, Anders

    2017-01-01

    Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition ...... mineral density) and psychological (e.g., low self-esteem) and underline the importance of careful clinical assessment of the patients.......Delayed puberty can be a source of great concern and anxiety, although it usually is caused by a self-limiting variant of the normal physiological timing named constitutional delay of growth and puberty (CDGP). Delayed puberty can, however, also be the first presentation of a permanent condition...

  20. A new surgical technique for concealed penis using an advanced musculocutaneous scrotal flap

    OpenAIRE

    Han, Dong-Seok; Jang, Hoon; Youn, Chang-Shik; Yuk, Seung-Mo

    2015-01-01

    Background Until recently, no single, universally accepted surgical method has existed for all types of concealed penis repairs. We describe a new surgical technique for repairing concealed penis by using an advanced musculocutaneous scrotal flap. Methods From January 2010 to June 2014, we evaluated 12 patients (12–40 years old) with concealed penises who were surgically treated with an advanced musculocutaneous scrotal flap technique after degloving through a ventral approach. All the patien...

  1. Delayed fission

    Energy Technology Data Exchange (ETDEWEB)

    Hatsukawa, Yuichi [Japan Atomic Energy Research Inst., Tokai, Ibaraki (Japan). Tokai Research Establishment

    1997-07-01

    Delayed fission is a nuclear decay process that couples {beta} decay and fission. In the delayed fission process, a parent nucleus undergoes {beta} decay and thereby populates excited states in the daughter. If these states are of energies comparable to or greater than the fission barrier of the daughter, then fission may compete with other decay modes of the excited states in the daughter. In this paper, mechanism and some experiments of the delayed fission will be discussed. (author)

  2. Total Lip Reconstruction with Tendinofasciocutaneous Radial Forearm Flap

    Directory of Open Access Journals (Sweden)

    Eldad Silberstein

    2014-01-01

    Full Text Available Introduction. Squamous cell carcinoma is a common tumour of lower lip. Small defects created by surgical resection may be readily reconstructed by linear closure or with local flaps. However, large tumours resection often results with microstomia and oral incompetence, drooling, and speech incomprehension. The goal of this study is to describe our experience with composite free radial forearm-palmaris longus tendon flap for total or near total lower lip reconstruction. Patients and Methods. This procedure was used in 5 patients with 80–100% lip defect resulting from Squamous cell carcinoma. Patients’ age ranged from 46 to 82 years. They are three male patients and two female. In 3 cases chin skin was reconstructed as well and in one case a 5 cm segment of mandible was reconstructed using radius bone. In one case where palmaris longus was missing hemi-flexor carpi radialis tendon was used instead. All patients tolerated the procedure well. Results. All flaps totally survived. No patient suffered from drooling. All patients regained normal diet and normal speech. Cosmetic result was fair to good in all patients accept one. Conclusion. We conclude that tendino-fasciocutaneous radial forearm flap for total lower lip reconstruction is safe. Functional and aesthetic result approaches reconstructive goals.

  3. EBF noise suppression and aerodynamic penalties. [Externally Blown Flaps

    Science.gov (United States)

    Mckinzie, L. J., Jr.

    1978-01-01

    Acoustic tests were conducted at model scale to determine the noise produced in the flyover and sideline planes at reduced separation distances between the nozzle exhaust plane and the flaps of an under-the-wing (UTW) externally blown flap (EBF) configuration in its approach attitude. Tests were also made to determine the noise suppression effectiveness of two types of passive devices which were located on the jet impingement surfaces of the configuration. In addition, static aerodynamic performance data were obtained to evaluate the penalties produced by these suppression devices. Broadband low frequency noise reductions were achieved by reducing the separation distance between the nozzle and flaps. However, mid and high frequency noise was produced which exceeded that of the reference configuration. Two passive noise suppression devices located on the flaps produced moderate to large noise reductions at reduced separation distances. Consideration of the static aerodynamic performance data obtained for the configurations tested suggests that specific broadband noise suppression characteristics may be obtained through a trade-off with aerodynamic performance penalties by the careful selection of suppression devices.

  4. [Perineal reconstruction: Salvage surgery with 2flaps technique].

    Science.gov (United States)

    Jiménez Gómez, Marta; Navarro-Sánchez, Antonio; Lima Sánchez, Jaime; Hernández Hernández, Juan Ramón

    2017-03-06

    The principles of perineal reconstructive surgery comprise adequate filling of the defect along with stable and durable skin coverage, with a low morbidity rate. Two-flap perineal reconstruction is a simple, fast and reliable technique that uses a single donor site. This improves scar position with low morbidity. It is based in the use of 2flaps; one flap fills the defect with a «turn over» technique and the other is a rotation - advancement flap for skin coverage. A 52-year-old male diagnosed with Lynch syndrome who underwent laparoscopic abdominoperineal amputation for adenocarcinoma of the lower rectum and developed recurrence 2years later over the perineal scar that required radical resection and perineal reconstruction. The use of this approach facilitates perineal reconstruction and enables treatment of patients with large and complex defects in frequently irradiated tissues where wound dehiscence and infection are common. Copyright © 2017 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  5. DIEAP flap for safe definitive autologous breast reconstruction.

    Science.gov (United States)

    Seidenstuecker, Katrin; van Waes, Carl; Munder, Beatrix I; Claes, Karel E Y; Witzel, Christian; Roche, Nathalie; Stillaert, Filip; Mahajan, Ajay L; Andree, Christoph; Blondeel, Phillip N

    2016-04-01

    Breast cancer is the commonest form of cancer in women affecting almost a quarter of a million patients in the US annually. 30 percent of these patients and patients with genetic mutations undergo removal of the breast, as highlighted in a high profile celebrity patient. Although breast reconstruction with free microvascular transfer of a DIEAP flap from the abdomen is an ideal form of reconstruction, there have been misgivings about the complexity and potential complications. This study was aimed at clearing these misunderstandings and establishing the value of this form of breast reconstruction. 1036 DIEAP flap breast reconstructions carried out at the University Hospital, Gent (five year period) and at the Sana Kliniken, Düsseldorf (three year period) were included prospectively. Comorbid factors like chemotherapy, radiotherapy, patient age >65 years, BMI >30 and smoking were recorded. Outcomes were evaluated over a mean follow up of 2 years. Overall complication rate related to the reconstructed breast and donor abdominal area was 6.8 percent. Total flap loss was seen in only 0.8 percent. The mean operating time was less than five hours. Older age, higher BMI, chemotherapy and radiotherapy did not have a significant influence on complication rates, however smoking resulted in significant delay in wound healing in the breast (p = 0.025) and abdominal wounds (p = 0.019). The DIEAP flap is an excellent option for breast reconstruction, with a low level of donor site morbidity and complications. It is an autologous reconstruction that provides a stable long term result. Copyright © 2015 Elsevier Ltd. All rights reserved.

  6. Time-dependent wave packet approach to the pulse delay effect upon RbI photoelectron spectrum

    Institute of Scientific and Technical Information of China (English)

    LIU Chunhua; MENG Qingtian; ZHANG Qinggang

    2006-01-01

    The time-resolved photoelectron spectrum (TRPES) of Rbl molecule is simulated using the time-dependent wave-packet method. Both the normal three-photon ionization process and auto-ionization process are involved in the simulation. The calculated results show that the change of delay time will influence the shape of the photoelectron spectrum (PES), and the influence is substantially due to the existence of the crossing between excited states and the strong laser field which will change the position of relevant curves.

  7. The place of nasolabial flap in orofacial reconstruction: A review

    Directory of Open Access Journals (Sweden)

    Amin Rahpeyma

    2016-12-01

    Conclusion: Nasolabial flap is an old flap for reconstructive purposes. Over time different modifications have been introduced to expand its usage. Clear definition of the terms used with this flap is given.

  8. Freestyle Local Perforator Flaps for Facial Reconstruction

    Directory of Open Access Journals (Sweden)

    Jun Yong Lee

    2015-01-01

    Full Text Available For the successful reconstruction of facial defects, various perforator flaps have been used in single-stage surgery, where tissues are moved to adjacent defect sites. Our group successfully performed perforator flap surgery on 17 patients with small to moderate facial defects that affected the functional and aesthetic features of their faces. Of four complicated cases, three developed venous congestion, which resolved in the subacute postoperative period, and one patient with partial necrosis underwent minor revision. We reviewed the literature on freestyle perforator flaps for facial defect reconstruction and focused on English articles published in the last five years. With the advance of knowledge regarding the vascular anatomy of pedicled perforator flaps in the face, we found that some perforator flaps can improve functional and aesthetic reconstruction for the facial defects. We suggest that freestyle facial perforator flaps can serve as alternative, safe, and versatile treatment modalities for covering small to moderate facial defects.

  9. Dermatosurgery Rounds - The Island SKIN Infraorbital Flap

    Directory of Open Access Journals (Sweden)

    Georgi Tchernev

    2017-07-01

    Full Text Available The main objective in dermatologic surgery is complete excision of the tumour while achieving the best possible functional and cosmetic outcome. Also we must take into account age, sex, and tumour size and site. We should also consider the patient's expectations, the preservation of the different cosmetic units, and the final cosmetic outcome. Various reconstructive methods ranging from secondary healing to free flap applications are usedfor the reconstruction of perinasal or facial defects caused by trauma or tumour surgery. Herein, we describe the nasal infraorbital island skin flap for the reconstruction in a patient with basal cell carcinoma. No complications were observed in operation field. The infraorbital island skin flap which we describe for the perinasal area reconstruction is a safe, easily performed and versatile flap. The multidimensional use of this flap together with a relatively easy reconstruction plan and surgical procedure would be effective in flap choice.

  10. Freestyle Local Perforator Flaps for Facial Reconstruction.

    Science.gov (United States)

    Lee, Jun Yong; Kim, Ji Min; Kwon, Ho; Jung, Sung-No; Shim, Hyung Sup; Kim, Sang Wha

    2015-01-01

    For the successful reconstruction of facial defects, various perforator flaps have been used in single-stage surgery, where tissues are moved to adjacent defect sites. Our group successfully performed perforator flap surgery on 17 patients with small to moderate facial defects that affected the functional and aesthetic features of their faces. Of four complicated cases, three developed venous congestion, which resolved in the subacute postoperative period, and one patient with partial necrosis underwent minor revision. We reviewed the literature on freestyle perforator flaps for facial defect reconstruction and focused on English articles published in the last five years. With the advance of knowledge regarding the vascular anatomy of pedicled perforator flaps in the face, we found that some perforator flaps can improve functional and aesthetic reconstruction for the facial defects. We suggest that freestyle facial perforator flaps can serve as alternative, safe, and versatile treatment modalities for covering small to moderate facial defects.

  11. Free flaps for pressure sore coverage.

    Science.gov (United States)

    Lemaire, Vincent; Boulanger, Kevin; Heymans, Oliver

    2008-06-01

    Management of pressure sores still represents a major challenge in plastic surgery practice due to recurrence. The surgeon may have to face multiple or recurrent pressure ulcerations without any local flap left. In this very limited indication, free flap surgery appears to be a useful adjunct in the surgical treatment. We reviewed our charts looking for patients operated for a pressure sore of the sacral, ischial, or trochanteric region. We found 88 consecutive patients representing 108 different pressure sores and 141 flap procedures. Among these patients, 6 presented large sores that could not be covered with a pedicled flap and benefited from free flap surgery (4.2% of all procedures). Stable coverage was achieved in 80% of these patients after a mean follow-up of 32 months. Comparison between pedicled and free flaps groups showed a trend in the latest concerning the presence of diabetes, incontinence, paraplegia, and male sex.

  12. Head and neck reconstruction with pedicled flaps in the free flap era

    NARCIS (Netherlands)

    Mahieu, R.; Colletti, G.; Bonomo, P.; Parrinello, G.; Iavarone, A.; Dolivet, G.; Livi, L.; Deganello, A.

    2016-01-01

    Nowadays, the transposition of microvascular free flaps is the most popular method for management of head and neck defects. However, not all patients are suitable candidates for free flap reconstruction. In addition, not every defect requires a free flap transfer to achieve good functional results.

  13. Resternal closure versus pectoral muscle flap following omental flap in treatment of deep sternal wound infection

    Directory of Open Access Journals (Sweden)

    Fouad Rassekh

    2016-05-01

    Conclusion: Omental flap is safe, easy and effective technique in management of mediastinitis with DSWI following open heart surgery in CABG patients either this procedure was followed by reclosure of the sternum or bilateral pectoral flap. However, reclosure of the sternum is more physiological and less invasive than doing bilateral pectoral flap leaving the sternum unclosed.

  14. Pectoralis major flap for head and neck reconstruction in era of free flaps.

    Science.gov (United States)

    Kekatpure, V D; Trivedi, N P; Manjula, B V; Mathan Mohan, A; Shetkar, G; Kuriakose, M A

    2012-04-01

    The aim of this study was to evaluate factors affecting the selection of pectoralis major flap in the era of free tissue reconstruction for post ablative head and neck defects and flap associated complications. The records of patients who underwent various reconstructive procedures between July 2009 and December 2010 were retrospectively analysed. 147 reconstructive procedures including 79 free flaps and 58 pectoralis major flaps were performed. Pectoralis major flap was selected for reconstruction in 21 patients (36%) due to resource constrains, in 12 (20%) patients for associated medical comorbidities, in 11 (19%) undergoing extended/salvage neck dissections, and in 5 patients with vessel depleted neck and free flap failure salvage surgery. None of the flaps was lost, 41% of patients had flap related complications. Most complications were self-limiting and were managed conservatively. Data from this study suggest that pectoralis major flap is a reliable option for head and neck reconstruction and has a major role even in this era of free flaps. The selection of pectoralis major flap over free flap was influenced by patient factors in most cases. Resource constraints remain a major deciding factor in a developing country setting.

  15. Posterior interosseous free flap: various types.

    Science.gov (United States)

    Park, J J; Kim, J S; Chung, J I

    1997-10-01

    The posterior interosseous artery is located in the intermuscular septum between the extensor carpi ulnaris and extensor digiti minimi muscles. The posterior interosseous artery is anatomically united through two main anastomoses: one proximal (at the level of the distal border of the supinator muscle) and one distal (at the most distal part of the interosseous space). In the distal part, the posterior interosseous artery joins the anterior interosseous artery to form the distal anastomosis between them. The posterior interosseous flap can be widely used as a reverse flow island flap because it is perfused by anastomoses between the anterior and the posterior interosseous arteries at the level of the wrist. The flap is not reliable whenever there is injury to the distal forearm or the wrist. To circumvent this limitation and to increase the versatility of this flap, we have refined its use as a direct flow free flap. The three types of free flaps used were (1) fasciocutaneous, (2) fasciocutaneous-fascia, and (3) fascia only. Described are 23 posterior interosseous free flaps: 13 fasciocutaneous flaps, 6 fasciocutaneous-fascial flaps, and 4 fascial flaps. There were 13 sensory flaps using the posterior antebrachial cutaneous nerve. The length and external diameter of the pedicle were measured in 35 cases. The length of the pedicle was on average 3.5 cm (range, 3.0 to 4.0 cm) and the external diameter of the artery averaged 2.2 mm (range, 2.0 to 2.5 mm). The hand was the recipient in 21 patients, and the foot in 2. All 23 flaps covered the defect successfully.

  16. Free flap pulse oximetry utilizing reflectance photoplethysmography

    OpenAIRE

    Zaman, T.; Kyriacou, P. A.; Pal, S.

    2013-01-01

    The successful salvage of a free flap is dependent on the continuous monitoring of perfusion. To date there is no widely accepted and readily available post-operative monitoring technique to reliably assess the viability of free flaps by continuously monitoring free flap blood oxygen saturation. In an attempt to overcome the limitations of the current techniques a reflectance photoplethysmographic (PPG) processing system has been developed with the capability of real-time estimation of arteri...

  17. Four Flaps Technique for Neoumbilicoplasty

    Directory of Open Access Journals (Sweden)

    Young Taek Lee

    2015-05-01

    Full Text Available The absence or disfigurement of the umbilicus is both cosmetically and psychologically distressing to patients. The goal of aesthetically pleasing umbilical reconstruction is to create a neoumbilicus with sufficient depth and good morphology, with natural-looking superior hooding and minimal scarring. Although many reports have presented techniques for creating new and attractive umbilici, we developed a technique that we term the "four flaps technique" for creating a neoumbilicus in circumstances such as the congenital absence of the umbilicus or the lack of remaining umbilical tissue following the excision of a hypertrophic or scarred umbilicus. This method uses the neighboring tissue by simply elevating four flaps and can yield sufficient depth and an aesthetically pleasing shape with appropriate superior hooding.

  18. Dynamic stall in flapping flight

    Science.gov (United States)

    Hubel, Tatjana; Tropea, Cameron

    2007-11-01

    We report on experiments concerning unsteady effects in flapping flight, conducted in the low-speed wind tunnel of the TU Darmstadt using a mechanical flapping-wing model. Particle Image Velocimetry (PIV) was used for qualitative and quantitative analysis parallel and perpendicular to the flow field. A sensitivity analysis of the main flight parameters has been performed, with specific attention to the flight envelope of 26,500 dynamic stall effect could be verified by the direct force measurement as well as the flow visualization. The observation of the leading-edge vortex for typical bird flight reduced frequencies shows that this flow cannot be approximated as being quasi- steady. This in effect proves that adaptive wings are necessary to fully control these unsteady flow features, such as dynamic stall.

  19. Free temporal fascia flap to cover soft tissue defects of the foot: a case report

    Directory of Open Access Journals (Sweden)

    Schreiber, Martin

    2015-01-01

    Full Text Available Severe soft tissue defects as a result of lye contamination remain a huge challenge in the interdisciplinary approach of trauma surgeons and plastic surgeons. Free tissue transfer is a suitable surgical option for successful reconstruction of form and function of defects in the distal parts of the lower extremities. We report the successful two-stage reconstruction of a full thickness lye contamination at the dorsum of the foot with a free temporoparietal fascia flap covered with a split-thickness skin graft from the thigh. The described method is a suitable operative alternative to anterolateral thigh flaps or other thin fascia flaps regarding flap harvest and donor site morbidity and should be considered in the portfolio of the plastic surgeon.

  20. Flapping Wing Flight Dynamic Modeling

    Science.gov (United States)

    2011-08-22

    von Karman, T. and Burgers, J. M., Gerneral Aerodynamic Theory - Perfect Fluids , Vol. II, Julius Springer , Berlin, 1935. [24] Pesavento, U. and Wang...L., Methods of Analytical Dynamics , McGraw-Hill Book Company, New York, 1970. [34] Deng, X., Schenato, L., Wu, W. C., and Sastry, S. S., Flapping...Micro air vehicle- motivated computational biomechanics in bio ights: aerodynamics, ight dynamics and maneuvering stability, Acta Mechanica

  1. Optimal propulsive flapping in Stokes flows

    CERN Document Server

    Was, Loic

    2014-01-01

    Swimming fish and flying insects use the flapping of fins and wings to generate thrust. In contrast, microscopic organisms typically deform their appendages in a wavelike fashion. Since a flapping motion with two degrees of freedom is able, in theory, to produce net forces from a time-periodic actuation at all Reynolds number, we compute in this paper the optimal flapping kinematics of a rigid spheroid in a Stokes flow. The hydrodynamics for the force generation and energetics of the flapping motion is solved exactly. We then compute analytically the gradient of a flapping efficiency in the space of all flapping gaits and employ it to derive numerically the optimal flapping kinematics as a function of the shape of the flapper and the amplitude of the motion. The kinematics of optimal flapping are observed to depend weakly on the flapper shape and are very similar to the figure-eight motion observed in the motion of insect wings. Our results suggest that flapping could be a exploited experimentally as a propul...

  2. Microsurgical free flaps at Kathmandu Model Hospital.

    Science.gov (United States)

    Rai, S M; Grinsell, D; Hunter-Smith, D; Corlett, R; Nakarmi, K; Basnet, S J; Shakya, P; Nagarkoti, K; Ghartimagar, M; Karki, B

    2014-01-01

    Microsurgery is an emerging subspecialty in Nepal. Microsurgery was started at Kathmandu Model Hospital in 2007 with the support from Interplast Australia and New Zealand. This study will be useful for establishing a baseline for future comparisons of outcome variables and for defining the challenges of performing microsurgical free flaps in Nepal. A retrospective cross sectional study was conducted using the clinical records of all the microsurgical free flaps performed at Kathmandu Model Hospital from April 2007 to April 2014. Fifty-six free flaps were performed. The commonest indication was neoplasm followed by post-burn contracture, infection and trauma. Radial artery forearm flap was the commonest flap followed by fibula, antero-lateral thigh, rectus, tensor facia lata, lattisimus dorsi, deep inferior epigastric artery perforator, and deep circumflex iliac artery flap. Radial artery forearm flaps and anterolateral thigh flaps were mostly used for burn contracture reconstructions. Twelve of the 13 (92%) fibulae were used for mandibular reconstruction for oral cancer and ameloblastoma. Rectus flaps were used mainly for covering defects over tibia. Hospital stay ranged from six to 67 days with an average of fourteen. Fifteen patients (26%) developed complications. The duration of operation ranged from six hours to 10.5 hours with an average of nine hours. The longest follow up was for four years. Microsurgery can be started even in very resource-poor center if there is support from advanced centers and if there is commitment of the institution and surgical team.

  3. Extended locoregional use of intercostal artery perforator propeller flaps.

    Science.gov (United States)

    Baghaki, Semih; Diyarbakirlioglu, Murat; Sahin, Ugur; Kucuksucu, Muge Anil; Turna, Akif; Baca, Bilgi; Aydın, Yağmur

    2017-05-01

    Besides conventional flaps, intercostal artery perforator flaps have been reported to cover trunk defects. In this report the use of anterior intercostal artery perforator (AICAP) flap, lateral intercostal artery perforator (LICAP) flap and dorsal intercostal artery perforator (DICAP) flap for thoracic, abdominal, cervical, lumbar and sacral defects with larger dimensions and extended indications beyond the reported literature were reevaluated. Thirty-nine patients underwent surgery between August 2012 and August 2014. The age of the patients ranged between 16 and 79 with a mean of 49 years. The distribution of defects were as follows; 12 thoracic, 8 parascapular, 3 cervical, 8 abdominal, 4 sacral and 4 lumbar. AICAP, LICAP and DICAP flaps were used for reconstruction. Fifty-two ICAP flaps were performed on 39 patients. Flap dimensions ranged between 6 × 9 cm and 14 × 35 cm. Twenty-six patients had single flap coverage and 13 patients had double flap coverage. Forty-six flaps have been transferred as propeller flaps and 6 flaps have been transferred as perforator plus flap. Forty flaps (75%) went through transient venous congestion. In one DICAP flap, 30% of flap was lost. No infection, hematoma or seroma were observed in any patient. Follow-up period ranged between 3 and 32 months with a mean of 9 months. The ICAP flaps provide reliable and versatile options in reconstructive surgery and can be used for challenging defects in trunk. © 2016 Wiley Periodicals, Inc.

  4. Previous Multiple Abdominal Surgeries: A Valid Contraindication to Abdominal Free Flap Breast Reconstruction?

    Science.gov (United States)

    Di Candia, Michele; Asfoor, Ahmed Al; Jessop, Zita M.; Kumiponjera, Devor; Hsieh, Frank; Malata, Charles M.

    2012-01-01

    Presented in part at the following Academic Meetings: 57th Meeting of the Italian Society of Plastic, Reconstructive and Aesthetic Surgery, September 24-27, 2008, Naples, Italy.45th Congress of the European Society for Surgical Research (ESSR), June 9-12, 2010, Geneva, Switzerland.British Association of Plastic Reconstructive and Aesthetic Surgeons Summer Scientific Meeting, June 30-July 2, 2010, Sheffield Hallam University, Sheffield, UK. Background: Patients with previous multiple abdominal surgeries are often denied abdominal free flap breast reconstruction because of concerns about flap viability and abdominal wall integrity. We therefore studied their flap and donor site outcomes and compared them to patients with no previous abdominal surgery to find out whether this is a valid contraindication to the use of abdominal tissue. Patients and Methods: Twenty patients with multiple previous abdominal operations who underwent abdominal free flap breast reconstruction by a single surgeon (C.M.M., 2000-2009) were identified and retrospectively compared with a cohort of similar patients without previous abdominal surgery (sequential allocation control group, n = 20). Results: The index and control groups were comparable in age, body mass index, comorbidities, previous chemotherapy, and RT exposure. The index patients had a mean age of 54 years (r, 42-63) and an average body mass index of 27.5 kg/m2 (r, 22-38). The main previous surgeries were Caesarean sections (19), hysterectomies (8), and cholecystectomies (6). They underwent immediate (n = 9) or delayed (n = 11) reconstructions either unilaterally (n = 18) or bilaterally (n = 2) and comprising 9 muscle-sparing free transverse rectus abdominis muscle and 13 deep inferior epigastric perforator flaps. All flaps were successful, and there were no significant differences in flap and donor site outcomes between the 2 groups after an average follow up of 26 months (r, 10-36). Conclusion: Multiple previous abdominal

  5. Power Minimization through Packet Retention in Cognitive Radio Sensor Networks under Interference and Delay Constraints: An Optimal Stopping Approach

    Directory of Open Access Journals (Sweden)

    Amr Y. Elnakeeb

    2016-04-01

    Full Text Available The aim of this article is twofold: First, we study the problem of packets retention in a queue with the aim of minimizing transmission power in delay-tolerant applications. The problem is classified as an optimal stopping problem. The optimal stopping rule has been derived as well. Optimal number of released packets is determined in each round through an Integer Linear Programming (ILP optimization problem. This transmission paradigm is tested via simulations in an interference-free environment leading to a significant reduction in transmission power (at least 55%. Second, we address the problem of applying the scheme of packets retention through the Optimal Stopping Policy (OSP to underlay Cognitive Radio Sensor Networks (CRSNs where strict interference threshold does exist. Simulations proved that our scheme outperforms traditional transmission method as far as dropped packet rate and Average Power per Transmitted Packet (APTP are concerned.

  6. Event-based state estimation for a class of complex networks with time-varying delays: A comparison principle approach

    Science.gov (United States)

    Zhang, Wenbing; Wang, Zidong; Liu, Yurong; Ding, Derui; Alsaadi, Fuad E.

    2017-01-01

    The paper is concerned with the state estimation problem for a class of time-delayed complex networks with event-triggering communication protocol. A novel event generator function, which is dependent not only on the measurement output but also on a predefined positive constant, is proposed with hope to reduce the communication burden. A new concept of exponentially ultimate boundedness is provided to quantify the estimation performance. By means of the comparison principle, some sufficient conditions are obtained to guarantee that the estimation error is exponentially ultimately bounded, and then the estimator gains are obtained in terms of the solution of certain matrix inequalities. Furthermore, a rigorous proof is proposed to show that the designed triggering condition is free of the Zeno behavior. Finally, a numerical example is given to illustrate the effectiveness of the proposed event-based estimator.

  7. Robust and Nonfragile H∞ Kalman-Type Filter Design for Parameter-Uncertain Time-Delay Systems: PLMI Approach

    Directory of Open Access Journals (Sweden)

    Seung Hyeop Yang

    2013-01-01

    Full Text Available This paper describes the synthesis of a robust and nonfragile H∞ Kalman-type filter design for a class of time-delay systems with polytopic uncertainties, filter-gain variations, and disturbances. We present the sufficient condition for filter existence and the method for designing a robust nonfragile H∞ filter by using LMIs (Linear Matrix Inequalities technique. Because the obtained sufficient condition can be represented as PLMIs (Parameterized Linear Matrix Inequalities, which can generate infinite LMIs, we use a relaxation technique to find finite solutions for a robust nonfragile H∞ filter. We show that the proposed filter can minimize estimation error in terms of parameter uncertainties, filter-fragility, and disturbances.

  8. Functional outcome after partial glossectomy with reconstruction using radial forearm free flap.

    Science.gov (United States)

    Joo, Young-Hoon; Hwang, Se-Hwan; Park, Jun-Ook; Cho, Kwang-Jae; Kim, Min-Sik

    2013-06-01

    The purpose of this study was to investigate the relationship between the radial forearm free flap (RFFF) volume changes and speech and swallowing outcomes. The study included 18 subjects with squamous cell carcinoma of the oral tongue. Average percentage changes in flap volume between 3 and 12 months was 19.2%. Postoperative free flap volume changes were significantly and negatively correlated with the word and sentence intelligibility (Y=-0.338X+43.641, r(2)=0.383, p=0.006 and Y=-0.246X+34.322, r(2)=0.321, p=0.014, respectively). A significant positive correlation was also found between word and sentence intelligibility and floor of mouth resected, postoperative irradiation. Postoperative flap volume changes between 3 and 12 months were correlated with reduced posterior bolus movement by tongue (p=0.002), reduced tongue base to posterior pharyngeal wall contact (p=0.002), reduced laryngeal elevation (p=0.005), increased aspiration (p=0.005), delayed oral (p=0.010) and pharyngeal transit time (p=0.011). Floor of mouth resected, tongue base resected, and postoperative irradiation also influenced the swallowing outcomes. This study shows that postoperative flap volume changes are significantly related to speech and swallowing outcomes in patients undergoing partial glossectomy reconstructed with RFFF. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  9. Modified Vertical Rectus Abdominis Musculocutaneous Flap for Limb Salvage Procedures in Proximal Lower Limb Musculoskeletal Sarcomas

    Directory of Open Access Journals (Sweden)

    Haitham H. Khalil

    2008-01-01

    Full Text Available Introduction and aim. Management of complicated wounds after tumor extipiration of pelvic and proximal lower limb musculoskeletal sarcoma represents an essential component in the outcome of these patients. The authors present modified vertical rectus abdominis musculocutaneous (VRAM flap techniques to reconstruct extensive defects after debridment of these complicated wounds. Material and Methods. Over a period of 4 years (2002–2005, 5 men and 2 women were managed. Median age was 21 years (range 15–49. The patients were managed for complicated lower trunk, groin, and upper thigh wounds after resection of three pelvic chondrosarcomas as well as two pelvic and two proximal femur osteosarcomas. The modifications included a VRAM flap with lateral and tongue-like extension design of the skin paddle (5 cases or a delayed extended VRAM flap (2 cases. Results. All flaps showed complete survival and healing with no ischemic events providing stable coverage. All patients were ambulant with good limb functions in terms of walking and gait after adequate rehabilitation, 2 needed support with crutches. Conclusion. The modified VRAM flaps offer reliable reconstructive tools for coverage of complex groin and thigh defects by providing larger well-vascularized soft tissue with acceptable donor site.

  10. Second Toe Plantar Free Flap for Volar Tissue Defects of the Fingers

    Directory of Open Access Journals (Sweden)

    Yong Jin Cho

    2013-05-01

    Full Text Available Background  The reconstruction of volar surface defects is difficult because of the specialhistologic nature ofthe tissue involved. The plantarsurface isthe most homologousin shapeand function and could be considered the mostideal ofreconstructive optionsin select casesof volar surface defects. In this paper, we evaluate a single institutional case series of volartissue defectsmanagedwith second toe plantarfree flaps.Methods  Asingle-institution retrospective reviewwas performed on 12 cases ofreconstructionusing a second toe plantar free flap. The mean age was 33 years (range, 9 to 54 years witha male-to-female ratio of 5-to-1. The predominant mechanism was crush injury (8 casesfollowed by amputations (3 cases and a single case of burn injury. Half of the indications (6caseswere forsoft-tissue defectswith the other halfforscar contracture.Results  All ofthe flapssurvived through the follow-up period. Sensory recoverywasrelatedto the time interval between injury and reconstruction−with delayed operations portendingworse outcomes. Therewere no postoperative complicationsin thisseries.Conclusions  Flexion contracture is the key functional deficit of volar tissue defects. Thesecond toe plantar free flap is the singular flap whose histology most closely matches thoseof the original volar tissue. In our experience, this flap is the superior reconstructive optionwithin the specific indications dictated by the defectsize and location.

  11. A New Approach for Design of Model Matching Controllers for Time Delay Systems by Using GA Technique

    Directory of Open Access Journals (Sweden)

    K. K. D Priyanka

    2015-01-01

    Full Text Available Modeling of physical systems usually results in complex high order dynamic representation. The simulation and design of controller for higher order system is a difficult problem. Normally the cost and complexity of the controller increases with the system order. Hence it is desirable to approximate these models to reduced order model such that these lower order models preserves all salient features of higher order model. Lower order models simplify the understanding of the original higher order system. Modern controller design methods such as Model Matching Technique, LQG produce controllers of order at least equal to that of the plant, usually higher order. These control laws are may be too complex with regards to practical implementation and simpler designs are then sought. For this purpose, one can either reduce the order the plant model prior to controller design, or reduce the controller in the final stage, or both. In the present work, a controller is designed such that the closed loop system which includes a delay response(s matches with those of the chosen model with same time delay as close as possible. Based on desired model, a controller(of higher order is designed using model matching method and is approximated to a lower order one using Approximate Generalized Time Moments (AGTM / Approximate Generalized Markov Moments (AGMM matching technique and Optimal Pade Approximation technique. Genetic Algorithm (GA optimization technique is used to obtain the expansion points one which yields similar response as that of model, minimizing the error between the response of the model and that of designed closed loop system.

  12. Crown lengthening: a surgical flap approach.

    Science.gov (United States)

    Lundergan, W; Hughes, W R

    1996-09-01

    In many instances it is not possible to place a restoration margin without encroaching on the periodontal attachment apparatus. A surgical crown-lengthening procedure can provide a good solution to this common clinical problem. This article discusses indication and contraindication for surgical crown-lengthening procedures and presents an appropriate surgical technique.

  13. Consecutive flap transfer for repairing massive soft tissue defects in the opisthenar with improved donor site closure

    Institute of Scientific and Technical Information of China (English)

    Wu Lehao; Tong Dedi; Zhu Shan; Zang Mengqing; Tian Guanglei; Chen Shanlin

    2014-01-01

    Objective:To explore a surgical model of utilizing consecutive free scapular flap and adjacent pedicled flap transfer for repairing massive soft tissue defects on the dorsum of the hand while minimizing the donor site morbidity.Methods:Six patients with massive soft tissue injuries on the opisthenar and forearm were treated with free scapular flaps.Afterwards,a pedicled flap adjacent to the donor site was transferred to cover the donor site defect by direct closure.Results:All six free scapular flaps survived without signs of infection.Three adjacent pedicled flaps presented minor signs of insufficient blood flow on the distal apex,which resolved after six weeks with only conservative therapy.All the incisions healed without other complications.At six-month follow-up,the patients regained full shoulder function.Conclusion:With the assistance of an adjacent pedicled flap,the scapular flap is a highly applicable approach in repairing massive soft tissue defects in the opisthenar.It can achieve positive outcomes in both reconstructive and aesthetic aspects.

  14. Using propensity score analysis to compare major complications between DIEP and free muscle-sparing TRAM flap breast reconstructions

    NARCIS (Netherlands)

    Zhong, Toni; Novak, Christine B.; Bagher, Shaghayegh; Maass, Saskia W. M. C.; Zhang, Jing; Arad, Udi; O'Neill, Anne C.; Metcalfe, Kelly A.; Hofer, Stefan O. P.

    2014-01-01

    BACKGROUND: Previous studies comparing muscle-sparing transverse rectus abdominis myocutaneous (TRAM) versus deep inferior epigastric artery perforator (DIEP) free flaps have not considered procedure selection bias. Propensity score analysis provides a statistical approach to consider preoperative f

  15. Suboptimal Control for Discrete Linear Systems with Time-delay: A Successive Approximation Approach%离散线性时滞系统的次优控制:逐次逼近法

    Institute of Scientific and Technical Information of China (English)

    唐功友; 王海红

    2005-01-01

    A successive approximation approach for designing optimal controllers is presented for discrete linear time-delay systems with a quadratic performance index. By using the successive approximation approach, the original optimal control problem is transformed into a sequence of nonhomogeneous linear two-point boundary value (TPBV) problems without time-delay and timeadvance terms. The optimal control law obtained consists of an accurate feedback terms and a time-delay compensation term which is the limit of the solution sequence of the adjoint equations.By using a finite-step iteration of the time-delay compensation term of the optimal solution sequence,a suboptimal control law is obtained. Simulation examples axe employed to test the validity of the proposed approach.

  16. Total ‘rib’-preservation technique of internal mammary vessel exposure for free flap breast reconstruction: A 5-year prospective cohort study and instructional video

    Science.gov (United States)

    Rosich-Medina, Anais; Bouloumpasis, Serafeim; Di Candia, Michele; Malata, Charles M.

    2015-01-01

    Introduction The total ‘rib’-preservation method of dissecting out the internal mammary vessels (IMV) during microvascular breast reconstruction aims to reduce free flap morbidity at the recipient site. We review our five-year experience with this technique. Patients & methods An analysis of a prospectively collected free flap data cohort was undertaken to determine the indications, operative details and reconstructive outcomes in all breast reconstruction patients undergoing IMV exposure using the total ‘rib’-preservation method by a single surgeon. Results 178 consecutive breast free flaps (156 unilateral, 11 bilateral) were performed from 1st June 2008 to 31st May 2013 in 167 patients with a median age of 50 years (range 28–71). There were 154 DIEP flaps, 14 SIEA flaps, 7 muscle-sparing free TRAMs, 2 IGAP flaps and one free latissimus dorsi flap. 75% of the reconstructions (133/178) were immediate, 25% (45/178) were delayed. The mean inter-costal space distance was 20.9 mm (range 9–29). The mean time taken to expose and prepare the recipient IMV's was 54 min (range 17–131). The mean flap ischaemia time was 95 min (range 38–190). Free flap survival was 100%, although 2.2% (4 flaps) required a return to theatre for exploration and flap salvage. No patients complained of localised chest pain or tenderness at the recipient site and no chest wall contour deformity has been observed. Discussion & conclusion The total ‘rib’-preservation technique of IMV exposure is a safe, reliable and versatile method for microvascular breast reconstruction and should be considered as a valid alternative to the ‘rib’-sacrificing techniques. PMID:26468373

  17. Internal Mammary Recipient Site Breast Cancer Recurrence Following Delayed Microvascular Breast Reconstruction

    Science.gov (United States)

    Rosich-Medina, Anais; Wang, Susan; Erel, Ertan; Malata, Charles M.

    2013-01-01

    Objective: The internal mammary vessels are a popular recipient site for microsurgical anastomoses of free flap breast reconstructions. We, however, observed 3 patients undergoing internal mammary vessel delayed free flap breast reconstruction that subsequently developed tumor recurrence at this site. We reviewed their characteristics to determine whether there was a correlation between delayed microsurgical reconstruction and local recurrence. Methods: A retrospective review of a single surgeon's delayed free flap breast reconstructions using the internal mammary vessels was conducted over a 7-year period to identify the time intervals between mastectomy and delayed breast reconstruction and between delayed breast reconstruction and recurrence. Results: Three patients developed local recurrence at the site of the microvascular anastomoses following delayed breast reconstruction. All patients had been disease-free following mastectomy. The median time interval between mastectomy and delayed breast reconstruction was 28 months (range = 20-120 months) while that between delayed breast reconstruction and local recurrence was 7 months (range = 4-10 months). Two patients died from metastatic disease, 36 and 72 months following their local recurrence. One patient remains alive 44 months after reconstruction. Conclusions: Local tumor recurrence at the internal mammary vessel dissection site following delayed breast reconstruction raises the question whether these 2 events may be related. Specifically, could internal mammary vessel dissection undertaken for delayed microsurgical reconstruction predispose to recurrence in the internal mammary lymph nodes? Further research is needed to ascertain whether delayed breast reconstruction increases the risk of local recurrence in this patient group. PMID:23383360

  18. 皮瓣延迟术对大鼠三血管体穿支皮瓣成活的影响及其机制%Effects of surgical delay procedure on the survival of perforator flap with three angiosomes in rat and its mechanism

    Institute of Scientific and Technical Information of China (English)

    李俊杰; 高自勉; 高伟阳; 李浙峰

    2014-01-01

    8)、(63±13)、(69 ±9)、(67±8)、(64±13) μm]及单纯延迟组术后3、7d闭塞区域2Ⅱ血管外径显著高于常规皮瓣组相应时相点血管外径水平[术后0、1、2、3、7d分别为(46±10)、(40 ±9)、(43±13)、(46±12)、(47±11)μm],q值为7.29~10.79,P值均小于0.05.常规皮瓣组、单纯延迟组大鼠术后3、7d以及延迟皮瓣组大鼠术后0、1、2d组内闭塞区域1与闭塞区域2间血管外径比较,差别明显(q值为5.32~9.56,P值均小于0.05).术后3、7d,常规皮瓣组及延迟皮瓣组大鼠闭塞区域1、单纯延迟组大鼠闭塞区域2血管外径显著高于组内术后0d(q值为6.12~8.13,P值均小于0.05).(2)术后7d内,常规皮瓣组、延迟皮瓣组大鼠皮瓣内来自蒂部的血液都顺利通过闭塞区域1覆盖血流动力学供区.术后0d,2组大鼠皮瓣内的血液越过闭塞区域1后均发生持续约3 min的血流阻塞现象,常规皮瓣组出现在闭塞区域2附近,延迟皮瓣组出现在闭塞区域2远端约1 cm处.(3)术后7d,延迟皮瓣组大鼠皮瓣成活率为(95±12)%,显著高于常规皮瓣组的(80±9)%(t=2.91,P <0.01),皮瓣部分坏死仅出现在潜在供区.(4)术后7d,与未行手术的左侧皮肤血管相比,常规皮瓣组大鼠皮瓣内闭塞区域1的血管扩张明显,相邻血管树间界限模糊,而闭塞区域2的血管变化轻微;延迟皮瓣组大鼠皮瓣内2个闭塞区域的血管均明显扩张. 结论 本实验的延迟方法可促进大鼠三血管体穿支皮瓣潜在供区的成活,其主要是通过皮瓣术前扩张闭塞区域2的闭塞血管实现的.%Objective To observe the effects of surgical delay procedure on the survival of perforator flap with three angiosomes in rat,and to explore its possible mechanism.Methods The flap model was a perforator flap with three angiosomes which located on the right dorsal side of a rat based on thc right deep circumflex iliac vessel.The two connection areas between the three angiosomes were

  19. Reconstruction of Complex Facial Defects Using Cervical Expanded Flap Prefabricated by Temporoparietal Fascia Flap.

    Science.gov (United States)

    Zhang, Ling; Yang, Qinghua; Jiang, Haiyue; Liu, Ge; Huang, Wanlu; Dong, Weiwei

    2015-09-01

    Reconstruction of complex facial defects using cervical expanded flap prefabricated by temporoparietal fascia flap. Complex facial defects are required to restore not only function but also aesthetic appearance, so it is vital challenge for plastic surgeons. Skin grafts and traditional flap transfer cannot meet the reconstructive requirements of color and texture with recipient. The purpose of this sturdy is to create an expanded prefabricated temporoparietal fascia flap to repair complex facial defects. Two patients suffered severe burns on the face underwent complex facial resurfacing with prefabricated cervical flap. The vasculature of prefabricated flap, including the superficial temporal vessel and surrounding fascia, was used as the vascular carrier. The temporoparietal fascia flap was sutured underneath the cervical subcutaneous tissue, and expansion was begun in postoperative 1 week. After 4 to 6 months of expansion, the expander was removed, facial scars were excised, and cervical prefabricated flap was elevated and transferred to repair the complex facial defects. Two complex facial defects were repaired successfully by prefabricated temporoparietal fascia flap, and prefabricated flaps survived completely. On account of donor site's skin was thinner and expanded too fast, 1 expanded skin flap was rupture during expansion, but necrosis was not occurred after the 2nd operation. Venous congestion was observed in 1 patient, but after dressing, flap necrosis was not happened. Donor site was closed primarily. Postoperative follow-up 6 months, the color, texture of prefabricated flap was well-matched with facial skin. This method of expanded prefabricated flap may provide a reliable solution to the complex facial resurfacing.

  20. Anomalous time delays of an optical pulse interacting with a micro-resonator: a quantum weak-measurement approach

    CERN Document Server

    Asano, M; Bliokh, Y P; Kofman, A G; Zhao, G; Ikuta, R; Yamamoto, T; Kivshar, Y S; Yang, L; Imoto, N; Ozdemir, S K; Nori, F

    2016-01-01

    We study inelastic resonant scattering of a Gaussian pulse with the parameters close to a zero of the complex scattering coefficient. We demonstrate, both theoretically and experimentally, that such near-zero scattering can result in anomalously-large time delays and frequency shifts of the scattered pulse. Furthermore, we reveal a close analogy of these anomalous shifts with the spatial and angular Goos-Hanchen optical beam shifts, which are amplified via quantum weak measurements. However, in contrast to other beam-shift and weak-measurement systems, we deal with a one-dimensional scalar wave without any intrinsic degrees of freedom. It is the non-Hermitian nature of the system that produces its rich and non-trivial behaviour. Our results are generic for any scattering problem, either quantum or classical. As an example, we consider the transmission of an optical pulse through a nano-fiber with a side-coupled toroidal micro-resonator. The zero of the transmission coefficient corresponds to the critical coup...

  1. Monocular SLAM for Visual Odometry: A Full Approach to the Delayed Inverse-Depth Feature Initialization Method

    Directory of Open Access Journals (Sweden)

    Rodrigo Munguía

    2012-01-01

    Full Text Available This paper describes in a detailed manner a method to implement a simultaneous localization and mapping (SLAM system based on monocular vision for applications of visual odometry, appearance-based sensing, and emulation of range-bearing measurements. SLAM techniques are required to operate mobile robots in a priori unknown environments using only on-board sensors to simultaneously build a map of their surroundings; this map will be needed for the robot to track its position. In this context, the 6-DOF (degree of freedom monocular camera case (monocular SLAM possibly represents the harder variant of SLAM. In monocular SLAM, a single camera, which is freely moving through its environment, represents the sole sensory input to the system. The method proposed in this paper is based on a technique called delayed inverse-depth feature initialization, which is intended to initialize new visual features on the system. In this work, detailed formulation, extended discussions, and experiments with real data are presented in order to validate and to show the performance of the proposal.

  2. The influence of mortality and socioeconomic status on risk and delayed rewards: a life history theory approach.

    Science.gov (United States)

    Griskevicius, Vladas; Tybur, Joshua M; Delton, Andrew W; Robertson, Theresa E

    2011-06-01

    Why do some people take risks and live for the present, whereas others avoid risks and save for the future? The evolutionary framework of life history theory predicts that preferences for risk and delay in gratification should be influenced by mortality and resource scarcity. A series of experiments examined how mortality cues influenced decisions involving risk preference (e.g., $10 for sure vs. 50% chance of $20) and temporal discounting (e.g., $5 now vs. $10 later). The effect of mortality depended critically on whether people grew up in a relatively resource-scarce or resource-plentiful environment. For individuals who grew up relatively poor, mortality cues led them to value the present and gamble for big immediate rewards. Conversely, for individuals who grew up relatively wealthy, mortality cues led them to value the future and avoid risky gambles. Overall, mortality cues appear to propel individuals toward diverging life history strategies as a function of childhood socioeconomic status, suggesting important implications for how environmental factors influence economic decisions and risky behaviors.

  3. Sensitivity analysis of a time-delayed thermo-acoustic system via an adjoint-based approach

    CERN Document Server

    Magri, Luca

    2013-01-01

    We apply adjoint-based sensitivity analysis to a time-delayed thermo-acoustic system: a Rijke tube containing a hot wire. We calculate how the growth rate and frequency of small oscillations about a base state are affected either by a generic passive control element in the system (the structural sensitivity analysis) or by a generic change to its base state (the base-state sensitivity analysis). We illustrate the structural sensitivity by calculating the effect of a second hot wire with a small heat release parameter. In a single calculation, this shows how the second hot wire changes the growth rate and frequency of the small oscillations, as a function of its position in the tube. We then examine the components of the structural sensitivity in order to determine the passive control mechanism that has the strongest influence on the growth rate. We find that a force applied to the acoustic momentum equation in the opposite direction to the instantaneous velocity is the most stabilizing feedback mechanism. We ...

  4. Analysis of biplane flapping flight with tail

    NARCIS (Netherlands)

    Tay, W.B.; Bijl, H.; Van Oudheusden, B.W.

    2012-01-01

    Numerical simulations have been performed to examine the interference effects between an upstream flapping biplane airfoil arrangement and a downstream stationary tail at a Reynolds number of 1000, which is around the regime of small flapping micro aerial vehicles. The objective is to investigate th

  5. Autobuttressing of colorectal anastomoses using a mesenteric flap.

    LENUS (Irish Health Repository)

    Mohan, H M

    2013-12-01

    Anastomotic leakage is a common and dreaded complication of colorectal surgery. Many different approaches have been tried to attempt to reduce leakage and associated morbidity. The concept of reinforcement of an anastomosis by buttressing is well established. Techniques described include using sutures, native omentum, animal or synthetic material. We report a technique for buttressing using a mesenteric flap to envelope the anastomosis. The primary rationale is to reduce clinical sequelae of anastomotic leakage by promoting local containment, as well as providing a scaffold for healing. Using autologous tissue provides a safe, time-efficient and cost-effective buttress without the risks of infection or reaction associated with foreign material. A mesenteric flap is particularly useful in patients in whom omentum is not available due to previous surgery, or to fill the dead space posterior to a low anastomosis within the pelvis.

  6. Gluteus maximus flap transfer for greater trochanter reconstruction in revision THA.

    Science.gov (United States)

    Whiteside, Leo A; Nayfeh, Tariq; Katerberg, Brian J

    2006-12-01

    We evaluated the results of an operative technique used in five patients (five hips) to reconstruct the greater trochanter with a gluteus maximus flap transfer during revision total hip arthroplasty. We exposed the hip through a posterior approach that split the gluteus maximus in its midsubstance. We then raised a flap from the posterior portion of the gluteus muscle that was elevated proximally to create a triangular muscle flap. The flap was sewn into the gap between the greater trochanter and lateral cortex of the femur and secured to the inner surface of the anterior capsule of the hip. With the hip abducted 10 degrees to 15 degrees, the edges of the gluteus maximus were closed over the flap and the greater trochanter. We compared the results of these patients with those of five patients (five hips) who had the trochanter left unrepaired and those of four patients (four hips) who had excision of the greater trochanter and suture closure of the intervening gap. The flap group had less pain, lower incidence of limp and Trendelenburg sign, and less need for support than the other two groups, but range of motion decreased.

  7. Perforator-based flaps for the treatment of burn scar contractures: a review.

    Science.gov (United States)

    Stekelenburg, C M; Marck, R E; Verhaegen, P D H M; Marck, K W; van Zuijlen, P P M

    2017-01-01

    Patients with burn scars often experience functional problems because of scar contractures. Surgical treatment may be indicated for those burn scar contractures. If the contractures are small and linear, the contraction bands can be treated with local transposition flaps like the Z-plasty. Broader, diffuse contractures are more challenging and require a different surgical approach, such as the use of local tissue. The use of perforator-based flaps is promising; however, their true clinical significance for this type of burn reconstructions still needs to be determined. Therefore, we performed a review to evaluate the role of perforator-based flaps for burn scar contracture treatment. Electronic databases were searched using a predefined search strategy. Studies evaluating the long-term outcome of perforator-based flaps for the treatment of burn scar contractures were included. The methodological quality was tested and data was summarized. Five hundred and ten papers were identified of which eleven met the inclusion criteria. One study was a randomized controlled trial; ten were cohort studies of a pre-postoperative design. The papers described outcomes of free flaps and local flaps. Most studies had methodological shortcomings and used inappropriate statistical methods. Perforator-based interposition flaps appear to be highly relevant for burn scar contracture treatment. However, due to the paucity and low quality of the studies that were assessed, no definitive conclusions about the true clinical significance could be reached. And therefore, only recommendations could be given for improvement of the quality of further primary research on the effectiveness of perforator-based flaps for burn scar contracture release.

  8. Piezoelectrically actuated insect scale flapping wing

    Science.gov (United States)

    Mukherjee, Sujoy; Ganguli, Ranjan

    2010-04-01

    An energy method is used in order to derive the non-linear equations of motion of a smart flapping wing. Flapping wing is actuated from the root by a PZT unimorph in the piezofan configuration. Dynamic characteristics of the wing, having the same size as dragonfly Aeshna Multicolor, are analyzed using numerical simulations. It is shown that flapping angle variations of the smart flapping wing are similar to the actual dragonfly wing for a specific feasible voltage. An unsteady aerodynamic model based on modified strip theory is used to obtain the aerodynamic forces. It is found that the smart wing generates sufficient lift to support its own weight and carry a small payload. It is therefore a potential candidate for flapping wing of micro air vehicles.

  9. Blood flow autoregulation in pedicled flaps

    DEFF Research Database (Denmark)

    Bonde, Christian T; Holstein-Rathlou, Niels-Henrik; Elberg, Jens J

    2009-01-01

    INTRODUCTION: Clinical work on the blood perfusion in skin and muscle flaps has suggested that some degree of blood flow autoregulation exists in such flaps. An autoregulatory mechanism would enable the flap to protect itself from changes in the perfusion pressure. The purpose of the present study...... was to evaluate if, and to what extent, a tissue flap could compensate a reduction in blood flow due to an acute constriction of the feed artery. Further, we wanted to examine the possible role of smooth muscle L-type calcium channels in the autoregulatory mechanism by pharmacological intervention with the L......-type calcium channel blocker nimodipine and the vasodilator papaverine. MATERIAL AND METHODS: Pedicled flaps were raised in pigs. Flow in the pedicle was reduced by constriction of the feed artery (n=34). A transit time flow probe measured the effect on blood flow continuously. Following this, three different...

  10. White light spectroscopy for free flap monitoring.

    Science.gov (United States)

    Fox, Paige M; Zeidler, Kamakshi; Carey, Joseph; Lee, Gordon K

    2013-03-01

    White light spectroscopy non-invasively measures hemoglobin saturation at the capillary level rendering an end-organ measurement of perfusion. We hypothesized this technology could be used after microvascular surgery to allow for early detection of ischemia and thrombosis. The Spectros T-Stat monitoring device, which utilizes white light spectroscopy, was compared with traditional flap monitoring techniques including pencil Doppler and clinical exam. Data were prospectively collected and analyzed. Results from 31 flaps revealed a normal capillary hemoglobin saturation of 40-75% with increase in saturation during the early postoperative period. One flap required return to the operating room 12 hours after microvascular anastomosis. The T-stat system recorded an acute decrease in saturation from ~50% to less than 30% 50 min prior to identification by clinical exam. Prompt treatment resulted in flap salvage. The Spectros T-Stat monitor may be a useful adjunct for free flap monitoring providing continuous, accurate perfusion assessment postoperatively.

  11. DIEP flap sentinel skin paddle positioning algorithm.

    Science.gov (United States)

    Laporta, Rosaria; Longo, Benedetto; Sorotos, Michail; Pagnoni, Marco; Santanelli Di Pompeo, Fabio

    2015-02-01

    Although clinical examination alone or in combination with other techniques is the only ubiquitous method for flap monitoring, it becomes problematic with buried free-tissue transfer. We present a DIEP flap sentinel skin paddle (SSP) positioning algorithm and its reliability is also investigated using a standardized monitoring protocol. All DIEP flaps were monitored with hand-held Doppler examination and clinical observation beginning immediately after surgery in recovery room and continued postoperatively at the ward. Skin paddle (SP) position was preoperatively drawn following mastectomy type incisions; in skin-sparing mastectomies types I-III a small SP (sSP) replaces nipple-areola complex; in skin-sparing mastectomy type IV, SSP is positioned between wise-pattern branches while in type V between medial/lateral branches. In case of nipple-sparing mastectomy SSP is positioned at inframammary fold or in lateral/medial branches of omega/inverted omega incision if used. Three hundred forty-seven DIEP flap breast reconstructions were reviewed and stratified according to SP type into group A including 216 flaps with large SP and group B including 131 flaps with SSP and sSP. Sixteen flaps (4.6%) were taken back for pedicle compromise, 13 of which were salvaged (81.25%), 11 among 13 from group A and 2 among 3 from group B. There was no statistical difference between the groups concerning microvascular complication rate (P = 0.108), and time until take-back (P = 0.521) and flap salvage rate (P = 0.473) resulted independent of SP type. Our results suggest that early detection of perfusion impairment and successful flaps salvage could be achieved using SSP for buried DIEP flap monitoring, without adjunctive expensive monitoring tests.

  12. Can we delay the replacement of this component?-an asset management approach to the question [for electric utilities

    DEFF Research Database (Denmark)

    Østergaard, Jacob; Jensen, A. Norsk

    2001-01-01

    Asset management is emerging as a new approach on how to exploit an electric utility physical asset in the most profitable way. One of the major questions to answer by the asset management staff is when to do replacements? This is a difficult question, which require weighting of several parameter...

  13. Early Intervention Approaches to Enhance the Peer-Related Social Competence of Young Children with Developmental Delays: A Historical Perspective

    Science.gov (United States)

    Guralnick, Michael J.

    2010-01-01

    This article presents a framework for future research and program development designed to support children's peer-related social competence. Intervention research is examined within a historical perspective culminating with a discussion of contemporary translational approaches capable of integrating models of normative development, developmental…

  14. Can we delay the replacement of this component?-an asset management approach to the question [for electric utilities

    DEFF Research Database (Denmark)

    Østergaard, Jacob; Jensen, A. Norsk

    2001-01-01

    Asset management is emerging as a new approach on how to exploit an electric utility physical asset in the most profitable way. One of the major questions to answer by the asset management staff is when to do replacements? This is a difficult question, which require weighting of several parameter...

  15. Exotic wakes of flapping fins

    DEFF Research Database (Denmark)

    Schnipper, Teis

    We present, in 8 chapters, experiments on and numerical simulations of bodies flapping in a fluid. Focus is predominantly on a rigid foil, a model fish, that performs prescribed pitching oscillations where the foil rotates around its leading edge. In a flowing soap film is measured, with unpreced...... of frequencies. Drag reductions up to a factor 3 are measured. Many results presented are obtained through flow visualisations. A great effort is made to produce visualisations of primarily high scientific quality, but often also with a certain aesthetic appeal....

  16. Clinical effect of triceps aponeurosis tongue-shaped flap approach for treatment of adult distal humerus fractures%肱三头肌舌形瓣入路行成人肱骨远端C型骨折内固定的疗效观察

    Institute of Scientific and Technical Information of China (English)

    刘景堂; 高秋明; 甄平; 葛宝丰

    2012-01-01

    Objective To investigate the clinical effect of the triceps aponeurosis tongue-shaped flap approach for treatment of adult distal humerus fractures. Methods From July 2004 to January 2011,22 cases of intraarticular fractures of the distal humerus were treated with open reduction and internal fixation through the triceps aponeurosis tongue-shaped flap approach. The clinical effects were evaluated through assessing the adequacy of operative exposure, visualization of the articular reduction and fixation, rate of bone union and recovery of the elbow joint function. Results The approach can provide adequate exposure for distal humerus AO/ASIF type C fractures, gradually increased excise motion may begin after 2 weeks of splinting, the mean time of bone union was 3.6 months, and no nonunion was occurred, good recovery was obtained. Conclusion The use of triceps aponeurosis tongue-shaped flap approach to gain acceses to the distal humerus provides adequate exposure and obtains good clinical result. It avoids the reported complications of olecranon osteotomy approach and is easily performed.%目的 观察肱三头肌舌形瓣入路行肱骨远端C型骨折内固定的应用效果.方法 自2004年7月~2011年1月应用肱三头肌舌形瓣入路行肱骨远端C型骨折内固定22例,观察术中显露效果、骨折愈合率和肘关节功能恢复情况.结果 术中可清晰显露,肱骨远端骨折及关节面均实现解剖对位,术后石膏托制动2周后逐渐开始肘关节功能锻炼,平均骨临床愈合时间3.6个月,关节功能普遍恢复良好.结论 采用肱三头肌舌形瓣入路,对肱骨远端C型骨折行骨折复位内固定,能够达到术中充分显露,肘关节功能恢复满意.

  17. Use of rotation scalp flaps for treatment of occipital baldness.

    Science.gov (United States)

    Juri, J; Juri, C; Arufe, H N

    1978-01-01

    We have used 25 rotation scalp flaps to treat occipital baldness associated with fronto-parietal baldness (the third flap), and 35 such flaps for the correction of isolated occipital baldness. We have not had any flap necrosis, and our patients have been well satisfied with the results of this surgery.

  18. Total endoscopic free flap harvest of a serratus anterior fascia flap for microsurgical lower leg reconstruction

    Directory of Open Access Journals (Sweden)

    Erdmann, Alfons

    2014-04-01

    Full Text Available [english] Background: A tremendous number of free flaps have been developed in the past. As the surgical result depends not only on a successful flap transfer but also on the harvest, this paper details the procedures for undertaking the first total endoscopic harvest of a serratus fascia flap for free flap transplantation to the lower leg. Patient and methods: In September 2012 we performed the first total endoscopic serratus anterior fascia free flap harvest. The incision of 2.5 cm length was made 10 cm in front of anterior muscle border of the latissimus dorsi at level with the midthorax. After insertion of a flexible laparoscopic single port system we started CO gas insufflation. We used this setting to meticulously prepare a neo cavity between atissimus dorsi and M. serratus anterior. The vessels were dissected and the thoraco-dorsal nerve was separated. With a second auxiliary incision we used a clamp to support the raising of the fascia flap from the underlying muscle. Finally we clipped the vessels to the latissimus dorsi muscle and the flap vessels at the Arteria and Vena axillaris. The flap was extracted via the 2.5 cm incision.Results: We were able to perform a total endoscopic harvest of a serratus fascia flap for free flap reconstruction of soft tissues. With this new operative technique we were able to avoid a long skin incision, which in our view lowers the morbidity at the harvest area.Conclusion: We describe a new method for the total endoscopic harvest of the serratus fascia flap for free flap transfer. The flap was harvested within reasonable time and following surgery leaves the patient with minimal donor site morbidity compared to the open technique.

  19. Reconstruction with fibular osteocutaneous free flap in patients with mandibular osteoradionecrosis

    OpenAIRE

    Kim, Min Gyun; Lee, Seung Tae; Park, Joo Yong; Choi, Sung Weon

    2015-01-01

    Background Osteoradionecrosis is a delayed complication from radiation therapy which causes chronic pain, infection and constant deformity after necrosis. Most of the osteoradionecrosis occurs spontaneously or after the primary oncologic surgery, dental extraction or by trauma of prosthesis. The treatment of osteoradionecrosis relies on both conservative measures and surgical measures. The fibular osteocutaneous free flap has become more popular choice for reconstruction of maxillofacial defe...

  20. Reconstruction of anterior skull base defects using frontalis muscle galea aponeurotica skull pedicle flaps

    Institute of Scientific and Technical Information of China (English)

    Kun Liu; Guanghui Wang; Hong Zhang; Yuping Wu; Yangcheng Lv; Jingsong Liu; Jieke Ma; Cheng Li; Jiang Zhu

    2013-01-01

    Objective: The aim of our study was to reconstruct soft and hard tissue perforating defects of the anterior skull base in a 1-stage surgical procedure with a combined craniofacial approach. Methods: Soft and hard tissue defects of the anterior skull base were successfully reconstructed in 43 patients during a 1-stage surgery through the use of frontalis muscle galea aponeurotica skull flaps with 1 or 2 vascularized pedicles. The skull flap areas were up approximately 7 cm × 14 cm. Results: Intracranial infection and cerebrospinal fluid leakage were not observed in the 43 patients, and all incisions healed. Of 33 malignant tumor patients, 25 patients received follow-up examinations for longer than 2 years, and 18 patients survived for 2 years. Conclusion: Frontalis muscle galea aponeurotica skull pedicle flaps provided a constant blood supply and resulted in soft and thin tissue. The pedicle flaps, together with the external cranial bone plate, strengthened the support, but still allowed for bending and shaping. In addition, the flap harvesting approach was consistent with surgery approach, without aesthetic compromises.

  1. Input-Output Approach to Control for Fuzzy Markov Jump Systems With Time-Varying Delays and Uncertain Packet Dropout Rate.

    Science.gov (United States)

    Zhang, Lixian; Ning, Zepeng; Shi, Peng

    2015-11-01

    This paper is concerned with H∞ control problem for a class of discrete-time Takagi-Sugeno fuzzy Markov jump systems with time-varying delays under unreliable communication links. It is assumed that the data transmission between the plant and the controller are subject to randomly occurred packet dropouts satisfying Bernoulli distribution and the dropout rate is uncertain. Based on a fuzzy-basis-dependent and mode-dependent Lyapunov function, the existence conditions of the desired H∞ state-feedback controllers are derived by employing the scaled small gain theorem such that the closed-loop system is stochastically stable and achieves a guaranteed H∞ performance. The gains of the controllers are constructed by solving a set of linear matrix inequalities. Finally, a practical example of robot arm is provided to illustrate the performance of the proposed approach.

  2. Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

    Science.gov (United States)

    Platt, Robert C

    1936-01-01

    This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash.

  3. Hydrodynamic schooling of flapping swimmers

    Science.gov (United States)

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  4. Delayed breast implant reconstruction

    DEFF Research Database (Denmark)

    Hvilsom, Gitte B.; Hölmich, Lisbet R.; Steding-Jessen, Marianne;

    2012-01-01

    We evaluated the association between radiation therapy and severe capsular contracture or reoperation after 717 delayed breast implant reconstruction procedures (288 1- and 429 2-stage procedures) identified in the prospective database of the Danish Registry for Plastic Surgery of the Breast during...... reconstruction approaches other than implants should be seriously considered among women who have received radiation therapy....

  5. Adaptive Trailing Edge Flaps for Active Load Alleviation in a Smart Rotor Configuration

    DEFF Research Database (Denmark)

    Bergami, Leonardo

    with flaps laid out on the outer 20 % of the blade span, from 77 % to 97% of the blade length. The configuration is first tested with a simplified cyclic control approach, which gives a preliminary indication of the load alleviation potential, and also reveals the possibility to enhance the rotor energy......-MPC requires lower flap activity, and also achieves higher reductions of the tower fatigue loads, thus indicating that a combined control approach that coordinates and integrates all available sensors and actuators has the potential for overall better results than achieved by a series of independent control...

  6. Reconstruction of lateral forefoot using reversed medial plantar flap with free anterolateral thigh flap.

    Science.gov (United States)

    Fujioka, Masaki; Hayashida, Kenji; Senju, Chikako

    2014-01-01

    Skin defects of the heel have frequently been reconstructed using the medial plantar flap; however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects.

  7. Pedicled Supraclavicular Artery Island Flap Versus Free Radial Forearm Flap for Tongue Reconstruction Following Hemiglossectomy.

    Science.gov (United States)

    Zhang, Senlin; Chen, Wei; Cao, Gang; Dong, Zhen

    2015-09-01

    This study investigated the tongue function and donor-site morbidity of patients with malignant tumors who had undergone immediate flap reconstruction surgery. Twenty-seven patients who had undergone immediate reconstruction after hemiglossectomy were observed. Twelve patients were reconstructed using the pedicled supraclavicular artery island flap (PSAIF) and 15 patients using the free radial forearm flap (FRFF). Flap survival, speech and swallowing function, and donor-site morbidity at the 6-month follow-up were evaluated. All the flaps were successfully transferred. No obvious complications were found in either the transferred flaps or donor regions. Age, sex, defect extent, speech and swallowing function were comparable between the 2 groups. Donor-site complications were less frequent with PSAIF reconstruction than FRFF reconstruction. The PSAIF is reliable and well suited for hemiglossectomy defect. It has few significant complications, and allows preservation of oral function.

  8. Regional flaps in head and neck reconstruction: a reappraisal.

    Science.gov (United States)

    Colletti, Giacomo; Tewfik, Karim; Bardazzi, Alessandro; Allevi, Fabiana; Chiapasco, Matteo; Mandalà, Marco; Rabbiosi, Dimitri

    2015-03-01

    Starting from our experience with 45 consecutive cases of regional pedicled flaps, we have underlined the effectiveness and reliability of a variety of flaps. The marketing laws as applied to surgical innovations are reviewed to help in the understanding of why regional flaps are regaining wide popularity in head and neck reconstruction. From January 2009 to January 2014, 45 regional flaps were harvested at San Paolo Hospital to reconstruct head and neck defects. These included 35 pectoralis major muscular and myocutaneous flaps, 4 lower trapezius island or pedicled flaps, 3 supraclavicular flaps, 2 latissimus dorsi pedicled flaps, and 1 fasciocutaneous temporal flap. The basic literature of marketing regarding the diffusion of new products was also reviewed. Two myocutaneous pectoralis major flaps were complicated by necrosis of the cutaneous paddle (one complete and one partial). No complete loss of any of the 45 flaps was observed. At 6 months of follow-up, 2 patients had died of multiple organ failure after prolonged sepsis. The 43 remaining patients had acceptable morphologic and functional results. Regional and free flaps appear to compete in many cases for the same indications. From the results of the present case series, regional flaps can be considered reliable reconstructive choices that are less expensive than their free flap alternatives. The "resurrection" of regional flaps can be partially justified by the changes in the global economy and the required adaptation of developed and developing countries. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  9. The Clinical Application of Anterolateral Thigh Flap

    Directory of Open Access Journals (Sweden)

    Yao-Chou Lee

    2011-01-01

    Furthermore, several modifications widen its clinical applications: the fascia lata can be included for sling or tendon reconstruction, the bulkiness could be created by including vastus lateralis muscle or deepithelization of skin flap, the pliability could be increased by suprafascial dissection or primary thinning, the pedicle length could be lengthening by proximally eccentric placement of the perforator, and so forth. Combined with these technical and conceptual advancements, the anterolateral thigh flap has become the workhorse flap for soft-tissue reconstructions from head to toe.

  10. New drag laws for flapping flight

    Science.gov (United States)

    Agre, Natalie; Zhang, Jun; Ristroph, Leif

    2014-11-01

    Classical aerodynamic theory predicts that a steadily-moving wing experiences fluid forces proportional to the square of its speed. For bird and insect flight, however, there is currently no model for how drag is affected by flapping motions of the wings. By considering simple wings driven to oscillate while progressing through the air, we discover that flapping significantly changes the magnitude of drag and fundamentally alters its scaling with speed. These measurements motivate a new aerodynamic force law that could help to understand the free-flight dynamics, control, and stability of insects and flapping-wing robots.

  11. 去骨瓣减压术后头皮表面积测量方法%An Approach for the Measurement of the Surface Area of Scalp Flap over the Cranial Defect after Decompressive Craniectomy

    Institute of Scientific and Technical Information of China (English)

    张钦虎; 刘兰娟; 赵宁辉; 赵金喜; 高莲; 孙鹤; 施心陵

    2013-01-01

    目的该文旨在介绍一种简单、快速并通用的测量方法,用于去骨瓣减压术后头皮表面积的测量。方法第一步,获取颅脑损伤病人去大骨瓣减压术后的颅脑CT图像,并将其导入Mimics软件;第二步,基于界定阈值,经Mimics软件三维化处理Dicom格式的原始图像获得颅脑和颅骨的三维几何模型;第三步,利用Mimics中的分割工具和测量工具对三维颅脑模型进行切割、分离、测量;第四步,通过数学计算方法估算出缺损区域的头表皮面积。结果应用该文所述的测量方法估算出了不同人群在不同颅脑损伤位置处的缺损区域头皮表面积。结论该文阐述了一种简单、快速、通用的新测量方法,运用此方法可以方便地估算出缺损区头皮表面积。%Objective To introduce a simple, fast and universal measuring method used in measurement of the surface area of scalp flap over the cranial defect after decompressive craniectomy. Methods The first step: CT images of the patient with craniocerebral trauma after decompressive craniectomy were obtained and imported into Mimics. The second step:based on the defined threshold, the 3D geometric models of brain and skul were reconstructed after the original Dicom format pictures three-dimensional processed by Mimics. The third step:based on the two builded 3D models, utilizing the segmentation and measurement tools of Mimics to conduct cutting, splitting and measuring operations for the 3D model of brain. The forth step: estimating the surface area of scalp flap over the removed bone flap by using mathematical computation methods. Results The application of the introduced method estimated the surface area of scalp flap over the cranial defect of different people with different position of craniocerebral trauma. Conclusions This paper introduces a simple, fast and universal new measuring method. We can conveniently estimate the surface area of scalp flap by

  12. Foot and ankle reconstruction: an experience on the use of 14 different flaps in 226 cases.

    Science.gov (United States)

    Zhu, Yue-Liang; Wang, Yi; He, Xiao-Qing; Zhu, Min; Li, Fu-Bin; Xu, Yong-Qing

    2013-11-01

    The aim of this report was to present our experience on the use of different flaps for soft tissue reconstruction of the foot and ankle. From 2007 to 2012, the soft tissue defects of traumatic injuries of the foot and ankle were reconstructed using 14 different flaps in 226 cases (162 male and 64 female). There were 62 pedicled flaps and 164 free flaps used in reconstruction. The pedicled flaps included sural flap, saphenous flap, dorsal pedal neurocutaneous flap, pedicled peroneal artery perforator flap, pedicled tibial artery perforator flap, and medial plantar flap. The free flaps were latissimus musculocutaneous flap, anterolateral thigh musculocutaneous flap, groin flap, lateral arm flap, anterolateral thigh perforator flap, peroneal artery perforator flap, thoracdorsal artery perforator flap, medial arm perforator flap. The sensory nerve coaptation was not performed for all of flaps. One hundred and ninety-four cases were combined with open fractures. One hundred and sixty-two cases had tendon. Among 164 free flaps, 8 flaps were completely lost, in which the defects were managed by the secondary procedures. Among the 57 flaps for plantar foot coverage (25 pedicled flaps and 32 free flaps), ulcers were developed in 5 pedicled flaps and 6 free flaps after weight bearing, and infection was found in 14 flaps. The donor site complications were seen in 3 cases with the free anterolateral thigh perforator flap transfer. All of limbs were preserved and the patients regained walking and daily activities. All of patients except for one regained protective sensation from 3 to 12 months postoperatively. Our experience showed that the sural flap and saphenous flap could be good options for the coverage of the defects at malleolus, dorsal hindfoot and midfoot. Plantar foot, forefoot and large size defects could be reconstructed with free anterolateral thigh perforator flap. For the infected wounds with dead spce, the free latissimus dorsi musculocutaneous flap remained to

  13. Ten-year experience of superior gluteal artery perforator flap for reconstruction of sacral defects in Tri-Service General Hospital

    Directory of Open Access Journals (Sweden)

    Chin-Ta Lin

    2014-01-01

    Full Text Available Background: Despite advances in reconstruction techniques, sacral sores continue to present a challenge to the plastic surgeon. The superior gluteal artery perforator (SGAP flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. However, the dissection of the perforator is tedious and carries a risk of compromising the perforator vessels. Patients and Methods: During the period between April 2003 and March 2013, 30 patients presented to our section with sacral wounds causing by pressure sores or infected pilonidal cysts. Of a total of 30 patients, 13 were female and 17 were male. Their ages ranged from 22 to 92 years old (mean 79.8 years old. Surgical intervention was performed electively with immediate or delayed reconstruction using a SGAP flap. The characteristics of patients′ age, and sex, and cause of sacral defect, co-morbidities, wound culture, flap size, perforator number, hospital stay, and outcome were reviewed. Results: For all operations, the length of the pedicle dissection will not exceed 1 cm because of the vascular anatomy of the SGAP, which lies adjacent to the sacral region. Due to short pedicle dissection, all SGAP flap were elevated around an hour. All flaps survived except two, which had partial flap necrosis and were finally treated by contralateral V-Y advancement flaps coverage. The mean follow-up period was 14.8 months (range 3-24. No flap surgery-related mortality was found. Conclusion: Perforator-based flaps have become popular in modern reconstructive surgery because of low donor site morbidity and good preservation of muscle. Our study shows that deep pedicle dissection is unnecessary when the surgery involves an accurate indicating perforator, adequate flap size design, and correct selection of flap utilization between tunnel and rotation. The

  14. Paramedian forehead flap combined with hinge flap for nasal tip reconstruction*

    Science.gov (United States)

    Cerci, Felipe Bochnia; Dellatorre, Gerson

    2016-01-01

    The paramedian forehead flap is a great option for restoration of complex nasal defects. For full-thickness defects, it may be used alone or in combination with other methods. We present a patient with a basal cell carcinoma on the distal nose treated by Mohs micrographic surgery, and a resulting full-thickness defect repaired with paramedian forehead flap combined with a hinge flap. For optimal results with the paramedian forehead flap, adequate surgical planning, patient orientation and meticulous surgical technique are imperative.

  15. Chronic Open Infective Lateral Malleolus Bursitis Management Using Local Rotational Flap

    Directory of Open Access Journals (Sweden)

    Yong-Beom Lee

    2017-01-01

    Full Text Available Background. Using a sinus tarsi rotational flap is an uncommon approach to treating chronic open infective lateral malleolus bursitis. Methods. We treated eight patients, including six males, using this approach. First, we debrided all the infected tissues and used a negative pressure wound closure system where needed. After acute infection had been controlled, the local rotational flap was used for cases where the wound could not be closed by a simple suture or bone exposure. The rotational flap was detached with a curved skin incision at the sinus tarsi next to the open wound and sutured to the defect, paying careful attention to the superficial peroneal nerve. The donor site was managed with a split-thickness skin graft. Results. The patients’ mean age was 74.1 years. Six patients had a wound after suppurative infection, but two patients had ulcer-type bursitis. Six patients demonstrated full flap healing, but two patients had venous congestion necrosis. Conclusion. A sinus tarsi rotational flap is a useful method to ensure healing and coverage of chronic open lateral malleolus bursitis, especially for small to medium wounds with cavity and bone exposure.

  16. Considering the Optimal Timing of Breast Reconstruction With Abdominal Flaps With Adjuvant Irradiation in 370 Consecutive Pedicled Transverse Rectus Abdominis Myocutaneous Flap and Free Deep Inferior Epigastric Perforator Flap Performed in a Chinese Oncology Center

    Science.gov (United States)

    He, Shanshan; Yin, Jian; Robb, Geoffrey L.; Sun, Jingyan; Zhang, Xuehui; Li, Haixin; Liu, Jing; Han, Chunyong

    2017-01-01

    Purpose There is an ongoing debate on the optimal sequence of radiation and breast reconstruction. The purpose of this article was to (a) assess the impact of radiation on autologous breast reconstruction and (b) analyze the best timing for autologous breast reconstruction in the setting of radiation in a Chinese population. Methods A retrospective review of patients undergoing breast reconstruction with autologous lower abdominal flaps between 2001 and 2014 in the Tianjin Medical University and Cancer Hospital was performed. Patients were grouped by their irradiation status (irradiated vs nonirradiated). The irradiated group was further stratified into 2 groups by the timing of irradiation (immediate breast reconstruction followed by radiation vs prior radiation and delayed breast reconstruction). The primary outcomes were early and late breast complications, secondary and revision surgeries to the reconstructed breast, whereas the secondary outcomes were aesthetic and psychological evaluations of the patients. Logistic regression was used to assess the potential association between irradiation, patient and treatment variables, and surgical outcomes. Results Three hundred sixty patients with 370 reconstructed breasts were included in the study. Two hundred seventy-eight cases were nonirradiated, of which 158 were immediate and 120 were delayed. Ninety-two cases were irradiated, of which 61 were immediate, and 31 were delayed. Three hundred thirty-two cases underwent pedicled transverse rectus abdominis myocutaneous flap, 38 had deep inferior epigastric perforator flap. The irradiated group had a significant increase in secondary surgery due to fat necrosis (P breast reconstruction. However, radiation and its timing did not have an adverse impact on patients' aesthetic and psychological evaluations by the Breast-Q survey. Conclusions Radiation administered to the reconstructed breast mound increased the rate of late complications and the need for secondary surgery

  17. H∞ State Feedback Delay-dependent Control for Discrete Systems with Multi-time-delay

    Institute of Scientific and Technical Information of China (English)

    Bai-Da Qu

    2005-01-01

    In this paper,H∞ state feedback control with delay information for discrete systems with multi-time-delay is discussed. Making use of linear matrix inequality (LMI) approach, a time-delay-dependent criterion for a discrete system with multi-time-delay to satisfy H∞ performance indices is induced, and then a strategy for H∞ state feedback control with delay values for plant with multi-time-delay is obtained. By solving corresponding LMI, a delay-dependent state feedback controller satisfying H∞ performance indices is designed. Finally, a simulation example demonstrates the validity of the proposed approach.

  18. Behind the performance of flapping flyers

    CERN Document Server

    Ramananarivo, Sophie; Thiria, Benjamin

    2010-01-01

    Saving energy and enhancing performance are secular preoccupations shared by both nature and human beings. In animal locomotion, flapping flyers or swimmers rely on the flexibility of their wings or body to passively increase their efficiency using an appropriate cycle of storing and releasing elastic energy. Despite the convergence of many observations pointing out this feature, the underlying mechanisms explaining how the elastic nature of the wings is related to propulsive efficiency remain unclear. Here we use an experiment with a self-propelled simplified insect model allowing to show how wing compliance governs the performance of flapping flyers. Reducing the description of the flapping wing to a forced oscillator model, we pinpoint different nonlinear effects that can account for the observed behavior ---in particular a set of cubic nonlinearities coming from the clamped-free beam equation used to model the wing and a quadratic damping term representing the fluid drag associated to the fast flapping mo...

  19. Periodic and Chaotic Flapping of Insectile Wings

    CERN Document Server

    Huang, Yangyang

    2015-01-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. The maximum power output of these flight muscles is insufficient to maintain such wing oscillations unless there is good elastic storage of energy in the insect flight system. Here, we explore the intrinsic self-oscillatory behavior of an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring. We study the wings behavior as a function of the total energy and spring stiffness. Three types of behavior are identified: end-over-end rotation, chaotic motion, and periodic flapping. Interestingly, the region of periodic flapping decreases as energy increases but is favored as stiffness increases. These findings are consistent with the fact that insect wings and flight muscles are stiff. They further imply that, by adjusting their muscle stiffness to the desired energy level, insects can maintain periodic flapping mechanically for a range of operating condit...

  20. Vascular anatomy of the anteromedial thigh flap

    Directory of Open Access Journals (Sweden)

    Jeremy Mingfa Sun

    2017-09-01

    Conclusion: The anatomy of the RFB, which is critical in the blood supply of the AMT flap, is constant and predictable. The location of the perforators is predictable, which aids preoperative planning.

  1. A dynamical system for interacting flapping swimmers

    Science.gov (United States)

    Oza, Anand; Ramananarivo, Sophie; Ristroph, Leif; Shelley, Michael

    2015-11-01

    We present the results of a theoretical investigation into the dynamics of interacting flapping swimmers. Our study is motivated by the recent experiments of Becker et al., who studied a one-dimensional array of self-propelled flapping wings that swim within each other's wakes in a water tank. They discovered that the system adopts certain ``schooling modes'' characterized by specific spatial phase relationships between swimmers. To rationalize these phenomena, we develop a discrete dynamical system in which the swimmers are modeled as heaving airfoils that shed point vortices during each flapping cycle. We then apply our model to recent experiments in the Applied Math Lab, in which two tandem flapping airfoils are free to choose both their speed and relative positions. We expect that our model may be used to understand how schooling behavior is influenced by hydrodynamics in more general contexts. Thanks to the NSF for its support.

  2. The flow around a flapping foil

    Science.gov (United States)

    Mandujano, Francisco; Malaga, Carlos

    2016-11-01

    The flow around a two-dimensional flapping foil immersed in a uniform stream is studied numerically using a Lattice-Boltzmann model, for Reynolds numbers between 100 and 250, and flapping Strouhal numbers between 0 . 01 and 0 . 6 . The computation of the hydrodynamic force on the foil is related to the wake structure. When the foil's is fixed in space, numerical results suggest a relation between drag coefficient behaviour and the flapping frequency which determines the transition from the von Kármán to the inverted von Kármán wake. When the foil is free of translational motion up-stream swimming at constant speed is observed at certain values of the flapping Strouhal. This work was partially supported by UNAM-DGAPA-PAPIIT Grant Number IN115316.

  3. Radical Surgical Excision and Use of Lateral Thoracic Flap for Intractable Axillary Hidradenitis Suppurativa

    Directory of Open Access Journals (Sweden)

    Wan-Lin Teo

    2012-11-01

    Full Text Available Current treatments for hidradenitis suppurativa (HS include prolonged courses of antibiotics, retinoids, immunosuppressants, and biologics. Severe cases that are resistant to prolonged medical treatment pose a therapeutic challenge. We propose radical excision and lateral thoracic flap reconstruction as a treatment option for such cases. In our experience with two patients, good aesthetic and functional outcomes were achieved, with a high level of patient satisfaction. The availability of suitable flap coverage allows for wide resection of all of the hair-bearing skin, leading to a low incidence of residual disease and subsequent recurrence. Following excision of the affected tissue, the ideal reconstructive method in the axilla provides suitable coverage without unacceptable donor site morbidity and also avoids axillary contractures. A long lateral thoracic flap with delay has excellent coverage with minimal donor tissue sacrifice. With a suitable flap coverage option, the management paradigm of intractable HS should shift from prolonged medical treatment to allow decisive radical excision, which will improve the quality of life for patients.

  4. Freestyle Local Perforator Flaps for Facial Reconstruction

    OpenAIRE

    Jun Yong Lee; Ji Min Kim; Ho Kwon; Sung-No Jung; Hyung Sup Shim; Sang Wha Kim

    2015-01-01

    For the successful reconstruction of facial defects, various perforator flaps have been used in single-stage surgery, where tissues are moved to adjacent defect sites. Our group successfully performed perforator flap surgery on 17 patients with small to moderate facial defects that affected the functional and aesthetic features of their faces. Of four complicated cases, three developed venous congestion, which resolved in the subacute postoperative period, and one patient with partial necrosi...

  5. Mastoid fascia kite flap for cryptotia correction.

    Science.gov (United States)

    Simon, François; Celerier, Charlotte; Garabedian, Erea-Noël; Denoyelle, Françoise

    2016-11-01

    Cryptotia is one of the most common malformations of the upper auricle with aesthetic and functional consequences, however there is no standard treatment. We present the surgical technique and results of a kite flap procedure which can be used in the different cryptotia subtypes. We reviewed all patients treated in our department from 2010 to 2015, using a mastoid fascia kite flap technique. The incision of this local flap follows the retro-auricular sulcus along the rim of the helix superiorly and drawing a skin paddle inferiorly. The mastoid fascia is exposed and a superiorly and posteriorly based flap is drawn and detached from the skull. Finally, the skin paddle is rotated and sutured between the superior helix and temporal skin creating the superior sulcus. The retro-auricular incision is closed directly inferiorly. Six patients (mean age 12) and seven ears were studied. One patient had bilateral cryptotia and only two had a normal contralateral ear. Mean follow-up was of 45 months. There was no skin necrosis, no complications reported and no revision surgery. We describe a reliable flap with a simple design and improved aesthetic result, as the thickness of the flap projects the helix well, the scar is entirely hidden in the retro-auricular sulcus and the direct suture induces a harmonious medialization of the inferior part of the ear and earlobe. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  6. Dorsal hand coverage with free serratus fascia flap

    DEFF Research Database (Denmark)

    Fotopoulos, Peter; Holmer, Per; Leicht, Pernille

    2003-01-01

    serratus fascia flap, the connective tissue over the serratus muscle, for dorsal hand coverage. The flap consists of thin and well-vascularized pliable tissue, with gliding properties excellent for covering exposed tendons. It is based on the branches of the thoracodorsal artery, which are raised...... in the flap, leaving the long thoracic nerve intact on the serratus muscle. Coverage of the flap with split-thickness skin graft is done immediately. The free serratus fascia flap is an ideal flap for dorsal hand coverage when the extensor tendons are exposed, especially because of low donor-site morbidity....

  7. Lower Extremity Reconstruction Using Vastus Lateralis Myocutaneous Flap versus Anterolateral Thigh Fasciocutaneous Flap

    Directory of Open Access Journals (Sweden)

    Min Jae Lee

    2012-07-01

    Full Text Available BackgroundThe anterolateral thigh (ALT perforator flap has become a popular option for treating soft tissue defects of lower extremity reconstruction and can be combined with a segment of the vastus lateralis muscle. We present a comparison of the use of the ALT fasciocutaneous (ALT-FC and myocutaneous flaps.MethodsWe retrospectively reviewed patients in whom free-tissue transfer was performed between 2005 and 2011 for the reconstruction of lower extremity soft-tissue defects. Twenty-four patients were divided into two groups: reconstruction using an ALT-FC flap (12 cases and reconstruction using a vastus lateralis myocutaneous (VL-MC flap (12 cases. Postoperative complications, functional results, cosmetic results, and donor-site morbidities were studied.ResultsComplete flap survival was 100% in both groups. A flap complication was noted in one case (marginal dehiscence of the ALT-FC group, and no complications were noted in the VL-MC group. In both groups, one case of partial skin graft loss occurred at the donor site, and debulking surgeries were needed for two cases. There were no significant differences in the mean scores for either functional or cosmetic outcomes in either group.ConclusionsThe VL-MC flap is able to fill occasional dead space and has comparable survival rates to ALT-FC with minimal donor-site morbidity. Additionally, the VL-MC flap is easily elevated without myocutaneous perforator injury.

  8. Lower Extremity Reconstruction Using Vastus Lateralis Myocutaneous Flap versus Anterolateral Thigh Fasciocutaneous Flap

    Directory of Open Access Journals (Sweden)

    Min Jae Lee

    2012-07-01

    Full Text Available Background The anterolateral thigh (ALT perforator flap has become a popular option fortreating soft tissue defects of lower extremity reconstruction and can be combined witha segment of the vastus lateralis muscle. We present a comparison of the use of the ALTfasciocutaneous (ALT-FC and myocutaneous flaps.Methods We retrospectively reviewed patients in whom free-tissue transfer was performedbetween 2005 and 2011 for the reconstruction of lower extremity soft-tissue defects. Twentyfourpatients were divided into two groups: reconstruction using an ALT-FC flap (12 cases andreconstruction using a vastus lateralis myocutaneous (VL-MC flap (12 cases. Postoperativecomplications, functional results, cosmetic results, and donor-site morbidities were studied.Results Complete flap survival was 100% in both groups. A flap complication was noted inone case (marginal dehiscence of the ALT-FC group, and no complications were noted in theVL-MC group. In both groups, one case of partial skin graft loss occurred at the donor site,and debulking surgeries were needed for two cases. There were no significant differences inthe mean scores for either functional or cosmetic outcomes in either group.Conclusions The VL-MC flap is able to fill occasional dead space and has comparable survivalrates to ALT-FC with minimal donor-site morbidity. Additionally, the VL-MC flap is easily elevatedwithout myocutaneous perforator injury.

  9. Rescue of Primary Incomplete Microkeratome Flap with Secondary Femtosecond Laser Flap in LASIK

    Directory of Open Access Journals (Sweden)

    E. A. Razgulyaeva

    2014-01-01

    Full Text Available For laser-assisted in situ keratomileusis (LASIK retreatments with a previous unsuccessful mechanical microkeratome-assisted surgery, some surgical protocols have been described as feasible, such as relifting of the flap or the creation of a new flap and even the change to a surface ablation procedure (photorefractive keratectomy (PRK. This case shows the use of femtosecond technology for the creation of a secondary flap to perform LASIK in a cornea with a primary incomplete flap obtained with a mechanical microkeratome. As we were unable to characterize the interface of the first partial lamellar cut, a thick flap was planned and created using a femtosecond laser platform. As the primary cut was very thick in the nasal quadrant, a piece of loose corneal tissue appeared during flap lifting which was fitted in its position and not removed. Despite this condition and considering the regularity of the new femtosecond laser cut, the treatment was uneventful. This case report shows the relevance of a detailed corneal analysis with an advanced imaging technique before performing a secondary flap in a cornea with a primary incomplete flap. The femtosecond laser technology seems to be an excellent tool to manage such cases successfully.

  10. The Internal Pudendal Artery Perforator Thigh Flap: A New Freestyle Pedicle Flap for the Ischial Region

    Directory of Open Access Journals (Sweden)

    Ichiro Hashimoto, MD

    2014-05-01

    Conclusions: The perforator vessels of the internal pudendal artery are very close to the ischial tuberosity. Blood flow to the flap is reliable when careful debridement of the pressure sore is performed. The iPap thigh flap is a new option for soft-tissue defects in the ischial region, including ischial pressure sores.

  11. The prepuce free flap in 10 patients : modifications in flap design and surgical technique

    NARCIS (Netherlands)

    Werker, Paul M N

    The prepuce free flap was used in 10 oral and oropharyngeal reconstructions. During the course of this study, various modifications took place. Residual penile skin necrosis and skin island necrosis early in the series led to modification of flap design. This solved the donor-site problem by placing

  12. The prepuce free flap in 10 patients : modifications in flap design and surgical technique

    NARCIS (Netherlands)

    Werker, Paul M N

    2002-01-01

    The prepuce free flap was used in 10 oral and oropharyngeal reconstructions. During the course of this study, various modifications took place. Residual penile skin necrosis and skin island necrosis early in the series led to modification of flap design. This solved the donor-site problem by placing

  13. Endoscopic closure of large septal perforations with bilateral Hadad-Bassagasteguy flaps.

    Science.gov (United States)

    Morera Serna, Eduardo; Ferrán de la Cierva, Luis; Fernández, Meritxell Tomás; Canut, Santiago Quer; Mesquida, Jacoba Alba; Purriños, Francisco José García

    2017-03-01

    Surgical closure of nasal septal perforations is one of the most challenging procedures in nasal surgery. Defects greater than 2 cm are especially difficult to repair with the traditional approaches due to the challenges of mobilizing enough mucosa to close big gaps, and avoiding airway stenosis in the process. We present a new technique to endoscopically close major septal perforations using bilateral Hadad-Bassagasteguy flaps. Four consecutive patients with septal perforations greater than 2 cm were operated at our institution. Bilateral Hadad-Bassagasteguy flaps were endoscopically raised, one of them above the defect and the other one below it, and rotated to partially cover the defect on each side. A deep temporalis fascia graft was sandwiched between the two flaps to provide a scaffold for schneiderian mucosa growth. Both flaps were covered with a silicone sheet for 3 weeks. A complete closure of the defect was accomplished in three of the four patients; partial closure was achieved in the other. Nasal crusting, epistaxis, and nasal breathing improved in all patients. Large defects of the nasal septum may be closed in selected cases by rotation of bilateral pedicled septal mucosal flaps partially covering the defect area, followed by secondary healing of the nasal mucosa over an autologous graft acting as an epithelial scaffold.

  14. Use of bipedicular advancement flaps for intrauterine closure of myeloschisis.

    Science.gov (United States)

    Mangels, K J; Tulipan, N; Bruner, J P; Nickolaus, D

    2000-01-01

    Several groups have begun to explore the feasibility and utility of intrauterine closure of myelomeningocele. A subset of these fetuses have defects which fall into the category of myeloschisis, and therefore have inadequate skin to enable primary closure. After considerable discussion, it was decided to utilize bipedicular flaps to close these lesions. The procedure is described, and representative examples are shown. To date, 13 of 56 fetuses have required this approach for closure in utero. While this technique generally provides adequate coverage of the dural sac, the cosmetic results have been less than optimal.

  15. Versatility of the Anterolateral Thigh Free Flap: The Four Seasons Flap

    Science.gov (United States)

    Di Candia, Michele; Lie, Kwok; Kumiponjera, Devor; Simcock, Jeremy; Cormack, George C.; Malata, Charles M.

    2012-01-01

    Presented at the following academic meetings: ○ 56th Meeting of the Italian Society of Plastic, Reconstructive and Aesthetic Surgery (SICPRE) Fasano (Brindisi), Italy, September 26-29, 2007 ○ 42nd Meeting of the European Society for Surgical Research (ESSR), Warsaw, Poland, May 21-24, 2008 ○ Winter Meeting, British Association of Plastic, Reconstructive and Aesthetic Surgeons, (BAPRAS) London, December 1-3, 2009 Background: The anterolateral free flap has become increasingly popular at our institution year on year. We decided to review our experience with this flap and study the reasons for this trend. Methods: A retrospective review of all anterolateral thigh free flaps performed at Addenbrooke's University Hospital from the available charts was carried out. This chart review included patients' demographics, indications, flap size, recipient vessels used, ischemia time, flap, and donor site outcomes. All flap perforator vessels were located preoperatively using a handheld Doppler ultrasound probe. Results: From October 1999 to December 2008, 55 anterolateral thigh flaps were performed in 55 patients to reconstruct a variety of soft-tissue defects (upper and lower limbs, chest wall, skull base, head and neck). Flap size ranged 12 to 35 cm in length and 4 to 11 cm in width. During flap elevation, the main supply to the flap was found to be a direct septocutaneous perforator in 41% (n = 23) of the cases as opposed to a musculocutaneous perforator, which was found in 59% (n = 32). The mean ischemia time was 82 minutes (range, 62-103). The overall flap success rate was 100%. Two flaps were successfully salvaged after reexploration for venous congestion. The donor site morbidity was minimal. The mean follow-up time was 18 months (range, 2-48). Discussion and Conclusion: The anterolateral thigh free flap was found to be a very reliable flap (100% success) across a wide range of clinical indications. It facilitates microvascular anastomoses as evidenced by the short

  16. Small delay approximation of stochastic delay differential equations

    Science.gov (United States)

    Guillouzic, Steve; L'heureux, Ivan; Longtin, André

    1999-04-01

    Delay differential equations evolve in an infinite-dimensional phase space. In this paper, we consider the effect of external fluctuations (noise) on delay differential equations involving one variable, thus leading to univariate stochastic delay differential equations (SDDE's). For small delays, a univariate nondelayed stochastic differential equation approximating such a SDDE is presented. Another approximation, complementary to the first, is also obtained using an average of the SDDE's drift term over the delayed dynamical variable, which defines a conditional average drift. This second approximation is characterized by the fact that the diffusion term is identical to that of the original SDDE. For small delays, our approach yields a steady-state probability density and a conditional average drift which are in close agreement with numerical simulations of the original SDDE. We illustrate this scheme with the delayed linear Langevin equation and a stochastic version of the delayed logistic equation. The technique can be used with any type of noise, and is easily generalized to multiple delays.

  17. Respiratory failure after superior-based pharyngeal flap for velopharyngeal insufficiency: A rare complication.

    Science.gov (United States)

    Lawlor, Claire M; Riley, Charles A; Hildrew, Douglas M; Guarisco, J Lindhe

    2015-07-01

    Velopharyngeal insufficiency (VPI) is an uncommon pediatric disorder often associated with congenital syndromes. After speech therapy, surgery is the standard management. Many surgical approaches to VPI repair have been reported and the complications of these procedures are well documented. To date, there have been no published cases of respiratory failure secondary to pneumomediastinum, pneumopericardium, and bilateral pneumothoraces with associated subcutaneous emphysema after superior-based pharyngeal flap. We present the first case in the literature. Our proposed etiology for the respiratory failure is air tracking from the flap donor site to the pleural spaces of the thoracic cavity via the visceral or prevertebral fascia following positive pressure ventilation.

  18. [Flap techniques in secondary alveoloplasty: a comparison between two types of flap].

    Science.gov (United States)

    Hugentobler, M; Dojcinovic, I; Richter, M

    2006-06-01

    The aim of this study was to compare two surgical soft tissue coverage techniques of secondary alveolar grafts in cleft lip and palate patients: the gingival mucoperiostal slidind flap and the mucosal rotation flap. Fifty-two secondary alveolar bone grafts were retrospectively included in the study. Four clinical parameters were evaluated: post-operative dehiscence, oro-nasal fistula relapse, canine eruption through the graft and postoperative secondary periodontal procedures. Gingival mucoperiostal flaps had less postoperative dehiscence, more fistula relapse and needed less secondary periodontal procedures. Based on this study and on literature data, gingival mucoperiostal flap provides better quality of soft tissue coverage. Flap design doesn't influence canine eruption. Bone graft complications are increased with poor oral hygiene, if canine eruption occurred before surgery and in older patients.

  19. Functional results of microvascular reconstruction after hemiglossectomy: free anterolateral thigh flap versus free forearm flap.

    Science.gov (United States)

    Tarsitano, A; Vietti, M V; Cipriani, R; Marchetti, C

    2013-12-01

    The aim of the present study is to assess functional outcomes after hemiglossectomy and microvascular reconstruction. Twenty-six patients underwent primary tongue microvascular reconstruction after hemiglossectomy. Twelve patients were reconstructed using a free radial forearm flap and 14 with an anterolateral thigh flap. Speech intelligibility, swallowing capacity and quality of life scores were assessed. Factors such as tumour extension, surgical resection and adjuvant radiotherapy appeared to be fundamental to predict post-treatment functional outcomes. The data obtained in the present study indicate that swallowing capacity after hemiglossectomy is better when an anterolateral thigh flap is used. No significant differences were seen for speech intelligibility or quality of life between free radial forearm flap and anterolateral thigh flap.

  20. The role of lidocaine, epinephrine, and flap elevation in wound healing after chemical peel.

    Science.gov (United States)

    Davies, B; Guyuron, B; Husami, T

    1991-03-01

    We have observed 5 patients with hypertrophic scarring at the lateral boundaries of the chemically peeled area when circumoral peel was combined with facial rhytidectomy. Some of the potential contributory factors include flap elevation, epinephrine, and lidocaine hydrochloride. To discover whether any one of these three factors or a combination played a role, a rat model study was designed. Initially, 40, 400-gm Sprague-Dawley rats were divided into 4 groups, each comprised by 10 rats. Injections with lidocaine or lidocaine with epinephrine, and chemical peel were done in 2 groups. The same injections were used in the remaining 2 groups together with simultaneous preliminary flap elevations and chemical peeling. After the review of the initial study results, another 40 Sprague-Dawley rats were used to repeat the study and compare on a larger scale the effects of lidocaine with and without epinephrine on the depth of chemical peel. The findings of the rat model studies indicate that preliminary injections with lidocaine containing solution (with or without epinephrine) result in a major delay in healing time. Flap elevation and chemical peeling were associated with major morbidity and mortality in the test rats. The presence of epinephrine in lidocaine solution had no significant role in increasing the delay in the healing process.

  1. Aerodynamic flight performance in flap-gliding birds and bats.

    Science.gov (United States)

    Muijres, Florian T; Henningsson, Per; Stuiver, Melanie; Hedenström, Anders

    2012-08-07

    Many birds use a flight mode called undulating or flap-gliding flight, where they alternate between flapping and gliding phases, while only a few bats make use of such a flight mode. Among birds, flap-gliding is commonly used by medium to large species, where it is regarded to have a lower energetic cost than continuously flapping flight. Here, we introduce a novel model for estimating the energetic flight economy of flap-gliding animals, by determining the lift-to-drag ratio for flap-gliding based on empirical lift-to-drag ratio estimates for continuous flapping flight and for continuous gliding flight, respectively. We apply the model to flight performance data of the common swift (Apus apus) and of the lesser long-nosed bat (Leptonycteris yerbabuenae). The common swift is a typical flap-glider while-to the best of our knowledge-the lesser long-nosed bat does not use flap-gliding. The results show that, according to the model, the flap-gliding common swift saves up to 15% energy compared to a continuous flapping swift, and that this is primarily due to the exceptionally high lift-to-drag ratio in gliding flight relative to that in flapping flight for common swifts. The lesser long-nosed bat, on the other hand, seems not to be able to reduce energetic costs by flap-gliding. The difference in relative costs of flap-gliding flight between the common swift and the lesser long-nosed bat can be explained by differences in morphology, flight style and wake dynamics. The model presented here proves to be a valuable tool for estimating energetic flight economy in flap-gliding animals. The results show that flap-gliding flight that is naturally used by common swifts is indeed the most economic one of the two flight modes, while this is not the case for the non-flap-gliding lesser long-nosed bat.

  2. Immediate breast reconstruction using the free lumbar artery perforator flap and lateral thoracic vein interposition graft for recipient lateral thoracic artery anastomosis

    Directory of Open Access Journals (Sweden)

    Toshihiko Satake

    2016-01-01

    Full Text Available The lumbar artery perforator (LAP flap, which contains excess skin and fat tissue, love handles, that extends from the lower back to upper buttock, may provide an alternate tissue source for autologous breast reconstruction. However, LAP flap use during this procedure frequently requires vessel interposition grafts to correct the short flap pedicle length and mismatched recipient vessel calibre. A 46-year-old patient underwent a right nipple-sparing mastectomy using a lateral approach for ductal carcinoma in situ and immediate LAP flap breast reconstruction. The lateral thoracic vessel served as the recipient vessel, and a lateral thoracic vein interposition graft from the distal remnant was performed to adjust the arterial length and size discrepancy between the recipient lateral thoracic artery and pedicle artery. This procedure facilitates microsurgical anastomosis and medialisation of LAP flap to make a natural decollete line and create a cleavage for the reconstructed breast.

  3. Management of Rectourethral Fistula following a Gunshot Injury with Gracilis Flap: A Case Report

    Directory of Open Access Journals (Sweden)

    Mutlu Değer

    2017-03-01

    Full Text Available Rectourethral fistulas are uncommon and can be classified as congenital or acquired. We present a case of rectourethral fistula following a shotgun injury and describe a surgical method of closing poorly healing defects between the urethra and rectum by means of a muscular flap of the gracilis muscle (GM. A 20-year-old man underwent laparotomy and colostomy for gunshot trauma. In postoperative first week, the patient began complaining of urine coming from the rectum. Retrograde urethrography revealed a fistulous opening connecting the prostatic urethra and the rectum. The transperineal approach with a GM flap interposition is currently the most commonly used method and one of the effective procedures for treating complex fistulae. Morbidity after a GM flap interposition is known to be low. GM transposition is a useful and effective method for the treatment of rectourethral fistula.

  4. Hypopharynx and larynx defect repair after resection for pyriform fossa cancer with a platysma skin flap.

    Science.gov (United States)

    Cai, Qian; Liang, Faya; Huang, Xiaoming; Han, Ping; Pan, Yong; Zheng, Yiqing

    2015-02-01

    We used a platysma skin flap to repair larynx and hypopharynx defects to improve postoperative laryngeal function in patients with pyriform fossa cancer. Larynx-sparing surgery and postoperative radiotherapy were used in 10 patients with pyriform fossa cancer. The surgical approaches of lymph node dissection of the neck, vertical partial laryngectomy, and pyriform fossa resection were adopted, and a platysma skin flap was used to repair the resulting defects. In this group, the overall 3-year survival rate was 75% according to the Kaplan-Meier analysis, and the local control rate was 90%. Additionally, all patients were able to speak fluently with mild-to-moderate hoarseness. The tracheal tube was removed in all cases. Laryngeal fistulas were observed in 1 patient during radiotherapy. In conclusion, a platysma skin flap can be used to rebuild the larynx and hypopharynx in larynx-sparing resection for pyriform fossa cancer. These patients can obtain good postoperative function in swallowing, breathing, and pronunciation.

  5. An experimental and analytical investigation of stall effects on flap-lag stability in forward flight

    Science.gov (United States)

    Nagabhushanam, J.; Gaonkar, Gopal H.; Mcnulty, Michael J.

    1987-01-01

    Experiments have been performed with a 1.62 m diameter hingeless rotor in a wind tunnel to investigate flap-lag stability of isolated rotors in forward flight. The three-bladed rotor model closely approaches the simple theoretical concept of a hingeless rotor as a set of rigid, articulated flap-lag blades with offset and spring restrained flap and lag hinges. Lag regressing mode stability data was obtained for advance ratios as high as 0.55 for various combinations of collective pitch and shaft angle. The prediction includes quasi-steady stall effects on rotor trim and Floquet stability analyses. Correlation between data and prediction is presented and is compared with that of an earlier study based on a linear theory without stall effects. While the results with stall effects show marked differences from the linear theory results, the stall theory still falls short of adequate agreement with the experimental data.

  6. Giant trochanteric pressure sore: Use of a pedicled chimeric perforator flap for cover

    Science.gov (United States)

    Mehrotra, Sandeep

    2009-01-01

    Pressure sores are increasing in frequency commensurate with an ageing population with multi-system disorders and trauma. Numerous classic options are described for providing stable wound cover. With the burgeoning knowledge on perforator anatomy, recent approaches focus on the use of perforator-based flaps in bedsore surgery. A giant neglected trochanteric pressure sore in a paraplegic is presented. Since conventional options of reconstruction appeared remote, the massive ulcer was successfully managed by a chimeric perforator-based flap. The combined muscle and fasciocutaneous flaps were raised as separate paddles based on the anterolateral thigh perforator branches and provided stable cover without complications. Perforators allow versatility in managing complex wounds without compromising on established principles. PMID:19881035

  7. Giant trochanteric pressure sore: Use of a pedicled chimeric perforator flap for cover

    Directory of Open Access Journals (Sweden)

    Mehrotra Sandeep

    2009-01-01

    Full Text Available Pressure sores are increasing in frequency commensurate with an ageing population with multi-system disorders and trauma. Numerous classic options are described for providing stable wound cover. With the burgeoning knowledge on perforator anatomy, recent approaches focus on the use of perforator-based flaps in bedsore surgery. A giant neglected trochanteric pressure sore in a paraplegic is presented. Since conventional options of reconstruction appeared remote, the massive ulcer was successfully managed by a chimeric perforator-based flap. The combined muscle and fasciocutaneous flaps were raised as separate paddles based on the anterolateral thigh perforator branches and provided stable cover without complications. Perforators allow versatility in managing complex wounds without compromising on established principles.

  8. Recurrent Fistula between Ileal Pouch and Vagina—Successful Treatment with a Gracilis Muscle Flap

    Directory of Open Access Journals (Sweden)

    Feride Aydin

    2009-01-01

    Full Text Available Fistulae between an ileal pouch and the vagina are an uncommon complication of ileal pouch-anal anastomosis following proctocolectomy and mucosectomy in patients with familial adenomatous polyposis coli. Several reports describe the successful use of muscle flaps to close recurrent pouch-vaginal-fistulae (PVF. However, series only contain small numbers and an optimal management has not yet been determined. We report the case of a 26-year old woman with a third recurrence of a PVF after proctocolectomy for treatment of familial adenomatous polyposis in October 2005. Because local approaches failed, definitive closure of the fistula was achieved by interposition of a gracilis muscle flap between the pouch-anal anastomosis and the vagina. The postoperative course was uneventful; the patient was discharged 7 days after surgery and remained free of recurrence and symptomatic complaints for 22 months now. The gracilis muscle flap proved to be an effective method in the treatment of recurrent PVF.

  9. Reconstruction of a complex midfacial defect with the folded fibular free flap and osseointegrated implants.

    Science.gov (United States)

    Anthony, J P; Foster, R D; Sharma, A B; Kearns, G J; Hoffman, W Y; Pogrel, M A

    1996-08-01

    Refinements in microsurgical techniques, plate fixation, and osseointegration have changed the conceptual approach to midface reconstruction. Free tissue transfer has emerged as the ideal method of reconstructing complex midfacial defects. Single-stage bony restoration of the palate and orbital rim using the folded fibular osteocutaneous free flap is described. The fibular free flap is our first choice for reconstructing complex midfacial defects. The thin, soft, pliable tissue is ideal for intraoral and palatal reconstructions. The bone can be tailored precisely to fit any desired shape, and forms a sturdy support for both orbital and dental prostheses. With a single flap, rapid and reliable restoration of midfacial appearance, orbital support, and palatal function can be achieved.

  10. Vascular Patterns and Perfusion of Mucogingival Tissues and their Relation to Periodontal Flap Design

    Science.gov (United States)

    1987-05-01

    flap coronal margins following exclusion of two values approaching two standard deviations from the mean. CORONAL MARGIN 20 LEGEND ISO PRESURGICAL...04 30 .15 115 992 man .12 .10 83 .11 91 110 max .08 .09 112 .07 87 110 man .18 .05 27 .07 38 mean . 13333 .09333 55.1 .10500 81 SD .03327 .04457 36.9

  11. Morbidity after flap reconstruction of hypopharyngeal defects.

    Science.gov (United States)

    Clark, Jonathan R; Gilbert, Ralph; Irish, Jonathan; Brown, Dale; Neligan, Peter; Gullane, Patrick J

    2006-02-01

    Laryngopharyngeal reconstruction continues to challenge in terms of operative morbidity and optimal functional results. The primary aim of this study is to determine whether complications can be predicted on the basis of reconstruction in patients undergoing pharyngectomy for tumors involving the hypopharynx. In addition, we detail a reconstructive algorithm for management of partial and total laryngopharyngectomy defects. A retrospective review was performed of 153 patients undergoing flap reconstruction for 85 partial and 68 circumferential pharyngectomies at a single institution over a 10-year period. There were 118 males and 35 females, the median age was 62 years, and mean follow up was 3.1 years. Pharyngectomy was performed for recurrence after radiotherapy in 80 patients and as primary surgery in 73. Free flap reconstruction was used in 42%, with 30 jejunal, 15 radial forearm, 11 anterolateral thigh, five rectus abdominis, and three gastro-omental flaps. Gastric transposition and pectoralis major pedicle flap was used in 14% and 44% of patients, respectively. Morbidity was analyzed according to extent of defect, regional versus free flap, enteric versus fasciocutaneous free flap reconstruction, and the effect of laparotomy. The total operative morbidity and mortality rate was 71% and 3%, respectively. The most common complications were hypocalcemia in 45%, pharyngocutaneous fistula in 33%, and wound complications in 25%. The late complication and stricture rate was 26% and 15%, respectively. On univariate analysis, circumferential defects were associated with increased total (P=.046) and flap-related morbidity (P=.037), hypocalcemia (Pspeech was the method of voice restoration in 44% of patients. Oral diet was achieved in 93% of patients; however, 16% required gastrostomy tube feeds for either total or supplemental nutrition. The operative morbidity associated with pharyngeal reconstruction is substantial in terms of early and late complications. We were

  12. Time Delay of CGM Sensors

    Science.gov (United States)

    Schmelzeisen-Redeker, Günther; Schoemaker, Michael; Kirchsteiger, Harald; Freckmann, Guido; Heinemann, Lutz; del Re, Luigi

    2015-01-01

    Background: Continuous glucose monitoring (CGM) is a powerful tool to support the optimization of glucose control of patients with diabetes. However, CGM systems measure glucose in interstitial fluid but not in blood. Rapid changes in one compartment are not accompanied by similar changes in the other, but follow with some delay. Such time delays hamper detection of, for example, hypoglycemic events. Our aim is to discuss the causes and extent of time delays and approaches to compensate for these. Methods: CGM data were obtained in a clinical study with 37 patients with a prototype glucose sensor. The study was divided into 5 phases over 2 years. In all, 8 patients participated in 2 phases separated by 8 months. A total number of 108 CGM data sets including raw signals were used for data analysis and were processed by statistical methods to obtain estimates of the time delay. Results: Overall mean (SD) time delay of the raw signals with respect to blood glucose was 9.5 (3.7) min, median was 9 min (interquartile range 4 min). Analysis of time delays observed in the same patients separated by 8 months suggests a patient dependent delay. No significant correlation was observed between delay and anamnestic or anthropometric data. The use of a prediction algorithm reduced the delay by 4 minutes on average. Conclusions: Prediction algorithms should be used to provide real-time CGM readings more consistent with simultaneous measurements by SMBG. Patient specificity may play an important role in improving prediction quality. PMID:26243773

  13. Intraoperative flap complications in lasik surgery performed by ophthalmology residents

    Directory of Open Access Journals (Sweden)

    Lorena Romero-Diaz-de-Leon

    2016-01-01

    Conclusion: Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye.

  14. Anterior Palatal Island Advancement Flap for Bone Graft Coverage ...

    African Journals Online (AJOL)

    2015 Journal of Surgical Technique and Case Report | Published by Wolters Kluwer - Medknow. 42. Anterior Palatal Island ... prosthodontic treatments should have ideal characteristics, as .... are rotated palatal flap and palatal advanced flap.

  15. Modified cup flap for volar oblique fingertip amputations

    Directory of Open Access Journals (Sweden)

    Ahmadli, A.

    2016-02-01

    Full Text Available We describe a modified volar “V-Y cup” flap for volar fingertip defects that do not exceed more than half of the distal phalanx for better aesthetic and functional outcome. In seven cases out of eight, the flap was elevated with a subdermal pedicle, whereas in one case, the flap was elevated as an island on the bilateral neurovascular bundle. The fingertips have been evaluated for sensibility using standard tests, hook nail deformity and patient satisfaction. Seven flaps have survived completely. The flap with skeletonized bilateral digital neurovascular bundle has shown signs of venous insufficiency on the 5 postoperative day with consecutive necrosis. Suturing the distal edges of the flap in a “cupping” fashion provided a normal pulp contour. The modified flap can be used for defects as mentioned above. Subdermally dissected pedicle-based flap is safe and easy to elevate. The aesthetic and functional outcomes have been reported to be satisfactory.

  16. [Alveolar ridge atrophy. The free vascularized fibular flap as alternative treatment in severe alveolar atrophy].

    Science.gov (United States)

    Rohner, Dennis

    2006-01-01

    Implant-supported overdentures are the goal of treatment of the edentulous atrophic jaw. To gain adequate height there is in some instances need for additional bone augmentation. Ridge augmentation using a free vascularised fibular flap is one of the newer techniques. Prefabrication of fibular flaps, as described in this article, is a two-stage procedure to overcome the problems of osseointegration and missing attached gingiva. Accurate pre-operative 3-D-model planning, implant placement and vestibuloplasty in the first stage allow for occlusion driven reconstruction and immediate function in the second stage after a delay of six weeks. Based on our clinical experience the technique and the results are discussed.

  17. Flow field of flexible flapping wings

    Science.gov (United States)

    Sallstrom, Erik

    The agility and maneuverability of natural fliers would be desirable to incorporate into engineered micro air vehicles (MAVs). However, there is still much for engineers to learn about flapping flight in order to understand how such vehicles can be built for efficient flying. The goal of this study is to develop a methodology for capturing high quality flow field data around flexible flapping wings in a hover environment and to interpret it to gain a better understanding of how aerodynamic forces are generated. The flow field data was captured using particle image velocimetry (PIV) and required that measurements be taken around a repeatable flapping motion to obtain phase-averaged data that could be studied throughout the flapping cycle. Therefore, the study includes the development of flapping devices with a simple repeatable single degree of freedom flapping motion. The acquired flow field data has been examined qualitatively and quantitatively to investigate the mechanisms behind force production in hovering flight and to relate it to observations in previous research. Specifically, the flow fields have been investigated around a rigid wing and several carbon fiber reinforced flexible membrane wings. Throughout the whole study the wings were actuated with either a sinusoidal or a semi-linear flapping motion. The semi-linear flapping motion holds the commanded angular velocity nearly constant through half of each half-stroke while the sinusoidal motion is always either accelerating or decelerating. The flow fields were investigated by examining vorticity and vortex structures, using the Q criterion as the definition for the latter, in two and three dimensions. The measurements were combined with wing deflection measurements to demonstrate some of the key links in how the fluid-structure interactions generated aerodynamic forces. The flow fields were also used to calculate the forces generated by the flapping wings using momentum balance methods which yielded

  18. A NUMERICAL AND ANALYTICAL STUDY ON A TAIL-FLAPPING MODEL FOR FISH FAST C-START

    Institute of Scientific and Technical Information of China (English)

    HU Wenrong; YU Yongliang; TONG Binggang; LIU Hao

    2004-01-01

    The force production physics and the flow control mechanism of fish fast C-start are studied numerically and theoretically by using a tail-flapping model. The problem is simplified to a 2-D foil that rotates rapidly to and fro on one side about its fixed leading edge in water medium. The study involves the simulation of the flow by solving the two-dimensional unsteady incompressible NavierStokes equations and employing a theoretical analytic modeling approach. Firstly, reasonable thrust magnitude and its time history are obtained and checked by fitting predicted results coming from these two approaches. Next, the flow fields and vortex structures are given, and the propulsive mechanism is interpreted. The results show that the induction of vortex distributions near the trailing edge of the tail are important in the time-averaged thrust generation, though the added inertial effect plays an important role in producing an instant large thrust especially in the first stage. Furthermore, dynamic and energetic effects of some kinematic controlling factors are discussed. For enhancing the timeaveraged thrust but keeping a favorable ratio of it to time-averaged input power within the limitations of muscle ability, it is recommended to have a larger deflection amplitude in a limited time interval and with no time delay between the to-and-fro strokes.

  19. A Previously Discounted Flap Now Reconsidered: MatriDerm and Split-Thickness Skin Grafting for Tendon Cover Following Dorsalis Pedis Fasciocutaneous Flap in Lower Limb Trauma.

    Science.gov (United States)

    Dunne, Jonathan A; Wilks, Daniel J; Rawlins, Jeremy M

    2014-01-01

    The dorsalis pedis flap has reliable vascularity; however, its use is limited by reports of donor site morbidity including infection, delayed healing, exposure of tendons, and later contractures. The purpose of this study was to demonstrate its continued role in lower limb trauma when the donor site is reconstructed with MatriDerm to avoid complications. A 65-year-old man presented with a displaced, Gustilo 3b open transverse fracture of his left distal fibula. He had a 2 cm(2) open wound over his lateral malleolus. Following review of possible local options, a dorsalis pedis fasciocutaneous flap was deemed best for coverage, and the donor site was closed with 1-mm MatriDerm dermal matrix and a 6/1000 inch split-thickness skin graft (STSG) in a single stage. Three months postoperatively, the foot had excellent function and cosmesis, with toes in a neutral position and a full range of movement. The dorsalis pedis flap is a valuable reconstructive option for defects of the foot and ankle. Its major limitation donor site morbidity can be overcome by the additional application of a dermal substitute such as MatriDerm under the STSG.

  20. 14 CFR 25.1511 - Flap extended speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 25.1511 Section 25... Limitations § 25.1511 Flap extended speed. The established flap extended speed V FE must be established so that it does not exceed the design flap speed V F chosen under §§ 25.335(e) and 25.345, for...

  1. Paramedian forehead flap thinning using a flexible razor blade.

    Science.gov (United States)

    Justiniano, Hilda; Edwards, Julia; Eisen, Daniel B

    2009-03-15

    Paramedian forehead flaps are sometimes required to resurface large or deep nasal defects. The flap often needs to be thinned to match the contour of the surrounding skin at the recipient site. We describe a technique to thin the distal potion of the paramedian forehead flap using a flexible razor blade, the Dermablade. Once familiar with it, this same technique may be applied to thin other interpolation flaps.

  2. The aerodynamic and structural study of flapping wing vehicles

    OpenAIRE

    2013-01-01

    This thesis reports on the aerodynamic and structural study carried out on flapping wings and flapping vehicles. Theoretical and experimental investigation of aerodynamic forces acting on flapping wings in simple harmonic oscillations is undertaken in order to help conduct and optimize the aerodynamic and structural design of flapping wing vehicles. The research is focused on the large scale ornithopter design of similar size and configuration to a hang glider. By means of Theodorsen’s th...

  3. "A Free thenar flap – A case report"

    OpenAIRE

    Chow Shew; Fung Boris KK; Garg Rajesh; Ip Wing

    2007-01-01

    Abstract We present a case report of a free thenar flap surgery done for a volar right hand middle finger, distal and middle phalanx degloving injury. A free thenar flap is a fasciocutaneous sensate flap supplied by a constant branch of the superficial radial artery and its variable nerve supply. It has a distinct advantage of low donor site morbidity, better cosmesis and texture of the flap. No immobilization is required postop. The donor site can be closed primiarily.

  4. The forked flap repair for hypospadias

    Directory of Open Access Journals (Sweden)

    Anil Chadha

    2012-01-01

    Full Text Available Context: Despite the abundance of techniques for the repair of Hypospadias, its problems still persist and a satisfactory design to correct the penile curvature with the formation of neourethra from the native urethral tissue or genital or extragenital tissues, with minimal postoperative complications has yet to evolve. Aim: Persisting with such an endeavor, a new technique for the repair of distal and midpenile hypospadias is described. Materials and Methods: The study has been done in 70 cases over the past 11 years. The "Forked-Flap" repair is a single stage method for the repair of such Hypospadias with chordee. It takes advantage of the rich vascular communication at the corona and capitalizes on the established reliability of the meatal based flip-flap. The repair achieves straightening of the curvature of the penis by complete excision of chordee tissue from the ventral surface of the penis beneath the urethral plate. The urethra is reconstructed using the native plate with forked flap extensions and genital tissue relying on the concept of meatal based flaps. Water proofing by dartos tissue and reinforcement by Nesbit′s prepucial tissue transfer completes the one stage procedure. Statistical Analysis: An analysis of 70 cases of this single stage technique of repair of penile hypospadias with chordee, operated at 3 to 5 years of age over the past 11 years is presented. Results and Conclusion: The Forked Flap gives comparable and replicable results; except for a urethrocutaneous fistula rate of 4% no other complications were observed.

  5. Comparative Study Between Two Flaps—Trapezoidal flap (TZF) and Ocshenbein-Leubke Flap (OLF) in Periapical Surgeries

    National Research Council Canada - National Science Library

    Ahmed, Mohd Viqar; Rastogi, Sanjay; Baad, Rajendra K; Gupta, Anurag K; Nishad, Sumita G; Bansal, Mansi; Kumar, Sanjeev; Oswal, Rakesh; Mahendra, P; Bhatnagar, Alok

    2013-01-01

    .... The large variety of flaps available for periapical surgeries reflects the number of variables to be considered before choosing an appropriate flap design. In this study; Ocshenbein-Leubke (OL) and trapezoidal (TZ...

  6. [Boomerang flap. A true single-stage pedicled cross finger flap].

    Science.gov (United States)

    Legaillard, P; Grangier, Y; Casoli, V; Martin, D; Baudet, J

    1996-06-01

    The indications for cover of long fingers have been considerably modified over recent years as a result of the concept of retrograde flow flaps. However, in some cases in which the dorsal digital networks cannot be used, cross-finger flaps are still indicated for cover of long fingers beyond the PIP joint. The authors present a new flap eliminating the need for this rather complicated procedure. The donor site takes advantage of the rich dorsal collateral arterial network of P1 of an adjacent healthy finger. The flap can be raised due to the constant existence of a bifurcation between the collateral dorsal digital arterial networks and the anastomoses situated at various levels between the dorsal and palmar collateral networks of the long fingers, which are constant as far as the PIP joint. A dorsolateral flap can therefore be raised from a healthy finger and transferred to the injured finger by raising the fatty connective tissue, including the dorsal collateral pedicles, in the shape of a boomerang. This flap covers distal defects from the PIP joint to the fingertip. The authors describe the anatomical basis for raising of the flap, the operative technique and report six clinical cases with a mean follow-up of 11 months.

  7. [Reconstruction of the oral cavity: the free radial forearm flap versus the free jejunal flap].

    Science.gov (United States)

    Belli, E; Cicconetti, A; Matteini, C

    1995-05-01

    The concentration in a restricted area such as the oral cavity of the essential anatomic structures for mastication, deglutition, speech, salivary drainage and respiration makes it indispensable to ensure not only the structural reconstruction of the region but also, and above all, a functional reconstruction of the anatomic unit affected by resection. The use of revascularised flaps has extended both the quantity and quality of reconstructive methods available. In the context of the oral cavity the most widely used flaps are the radial forearm free flap and jejunum free flap. In this paper the authors report their personal experience in a group of 13 patients (6 radial forearm and 7 jejunum) undergoing oral cavity reconstruction using free flap. For each flap the authors describe the microsurgical procedure, the clinical characteristics of the post-operative period, the locoregional complications, the donor site and lastly the long-term clinical, anatomopathological and functional modifications 6-12 months after primary treatment. Moreover, they highlight the varying characteristics of the two flaps and make a critical assessment of the advantages and disadvantages of using one or other method. Lastly, in the light of their experience and a review of international literature, the authors underline the importance of making a careful choice and personalized reconstruction, and finally outline their own criteria of choice.

  8. 14 CFR 23.1511 - Flap extended speed.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap extended speed. 23.1511 Section 23.1511 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT... Information § 23.1511 Flap extended speed. (a) The flap extended speed V FE must be established so that it...

  9. Posttraumatic eyebrow reconstruction with hair-bearing temporoparietal fascia flap.

    Science.gov (United States)

    Denadai, Rafael; Raposo-Amaral, Cassio Eduardo; Marques, Frederico Figueiredo; Raposo-Amaral, Cesar Augusto

    2015-01-01

    The temporoparietal fascia flap has been extensively used in craniofacial reconstructions. However, its use for eyebrow reconstruction has been sporadically reported. We describe a successfully repaired hair-bearing temporoparietal fascia flap after traumatic avulsion of eyebrow. Temporoparietal fascia flap is a versatile tool and should be considered as a therapeutic option by all plastic surgeons.

  10. Posttraumatic eyebrow reconstruction with hair-bearing temporoparietal fascia flap

    Science.gov (United States)

    Denadai, Rafael; Raposo-Amaral, Cassio Eduardo; Marques, Frederico Figueiredo; Raposo-Amaral, Cesar Augusto

    2015-01-01

    The temporoparietal fascia flap has been extensively used in craniofacial reconstructions. However, its use for eyebrow reconstruction has been sporadically reported. We describe a successfully repaired hair-bearing temporoparietal fascia flap after traumatic avulsion of eyebrow. Temporoparietal fascia flap is a versatile tool and should be considered as a therapeutic option by all plastic surgeons. PMID:25993077

  11. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    Science.gov (United States)

    Kim, Chae Min; Yun, In Sik; Lee, Dong Won; Lew, Dae Hyun; Rah, Dong Kyun

    2014-01-01

    Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores) whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50%) had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years). The mean follow-up period was 27.9 months (range, 3-57 months). In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%), wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%), but resolved with conservative treatment. Among 16 cases, there was only one (6%) recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores. PMID:25075362

  12. Treatment of Ischial Pressure Sores with Both Profunda Femoris Artery Perforator Flaps and Muscle Flaps

    Directory of Open Access Journals (Sweden)

    Chae Min Kim

    2014-07-01

    Full Text Available Background Reconstruction of ischial pressure sore defects is challenging due to extensive bursas and high recurrence rates. In this study, we simultaneously applied a muscle flap that covered the exposed ischium and large bursa with sufficient muscular volume and a profunda femoris artery perforator fasciocutaneous flap for the management of ischial pressure sores. Methods We retrospectively analyzed data from 14 patients (16 ischial sores whose ischial defects had been reconstructed using both a profunda femoris artery perforator flap and a muscle flap between January 2006 and February 2014. We compared patient characteristics, operative procedure, and clinical course. Results All flaps survived the entire follow-up period. Seven patients (50% had a history of surgery at the site of the ischial pressure sore. The mean age of the patients included was 52.8 years (range, 18-85 years. The mean follow-up period was 27.9 months (range, 3-57 months. In two patients, a biceps femoris muscle flap was used, while a gracilis muscle flap was used in the remaining patients. In four cases (25%, wound dehiscence occurred, but healed without further complication after resuturing. Additionally, congestion occurred in one case (6%, but resolved with conservative treatment. Among 16 cases, there was only one (6% recurrence at 34 months. Conclusions The combination of a profunda femoris artery perforator fasciocutaneous flap and muscle flap for the treatment of ischial pressure sores provided pliability, adequate bulkiness and few long-term complications. Therefore, this may be used as an alternative treatment method for ischial pressure sores.

  13. Full-Thickness Entire Nasal Alar Reconstruction Using a Forehead Flap in Asians: No Cartilaginous Infrastructural Lining Is Necessary.

    Science.gov (United States)

    Funayama, Emi; Yamamoto, Yuhei; Furukawa, Hiroshi; Murao, Naoki; Shichinohe, Ryuji; Yamao, Takeshi; Hayashi, Toshihiko; Oyama, Akihiko

    2017-05-01

    Full-thickness defects of the entire nasal ala, including the rim, can be challenging to reconstruct. A forehead flap may provide a more imperceptible and natural-appearing reconstructed nasal ala. Previously, many authors have insisted adding cartilaginous infrastructural support for an entire, full-thickness defect to keep the postoperative alar structure symmetrical. They finally use a forehead flap after thinning of the distal covering portion subcutaneously, possibly for a Caucasian-type nasal ala. However, Asian skin has a thicker and more compact dermis than that of Caucasian skin, and the Asian ala is rounder and thicker. There may be another approach for an Asian-type nasal ala. The authors propose the possibility of nasal alar reconstruction for an entire, full-thickness defect in Asians using a forehead flap without structural support. Six patients with entire full-thickness nasal alar defects treated with full-thickness forehead flaps above the periosteum without structural support were reviewed. Five patients demonstrated esthetically good to excellent outcomes in color, texture, and symmetry. Their nasal linings were reconstructed using mucoperiosteal flaps or mucosal grafts. One patient treated with a nasal lining using a local flap showed a fair result esthetically. Asians forehead above the periosteum has adequate thickness and supportability to reconstruct the entire full-thickness nasal ala in Asians. No cartilage support is necessary.

  14. Single-stage maxillary and nasal floor reconstruction with the double-paddle rectus abdominis musculocutaneous free flap.

    Science.gov (United States)

    Herman, Charles K; Benacquista, Teresa; Brindzei, Nelya; Berdichevsky, Max; Baum, Thomas; Strauch, Berish

    2007-04-01

    Palatal integrity is essential for useful speech, deglutition, good oral hygiene, and prevention of nasal regurgitation. Maxillary defects after tumor extirpation, therefore, can have serious functional and cosmetic implications. Given the often disappointing results obtained with local and regional pedicled flaps for maxillary reconstruction, a variety of microvascular free flaps have been utilized in recent years, including the rectus abdominis, fibular, radial forearm, and latissimus dorsi flaps. Experience with these techniques has been documented in a limited number of case reports. We describe our single-stage approach to maxillary and nasal floor reconstruction with the double skin-paddle rectus abdominis musculocutaneous free flap. A series of five patients is presented; six of these immediate free flap reconstructions were performed for defects resulting from tumor resection. A vertical rectus abdominis musculocutaneous free flap was used in all cases, designing two separate skin paddles to accommodate the measured maxillary and nasal floor deficiencies. Anastomoses of the deep inferior epigastric artery and vena comitans were performed end-to-end to the facial artery and vein, respectively. In addition, orbital floor reconstruction with calvarial bone grafts or titanium mesh was performed in all five patients. Separation of the oral and nasal cavities was maintained postoperatively. No intraoperative complications, perioperative mortalities, flap losses, instances of skin paddle necrosis, hematomas, or oronasal fistulae were observed. One patient required bedside drainage of a surgical site abscess that resolved without adverse sequelae. Over the past 4 years, the double skin-paddle rectus abdominis musculocutaneous free flap has provided reliable results at our institution for single-stage reconstruction of maxillary and nasal floor defects. This reconstructive technique should be considered a viable method that can alleviate the functional and cosmetic

  15. The angel flap for nipple reconstruction.

    Science.gov (United States)

    Wong, Wendy W; Hiersche, Matthew A; Martin, Mark C

    2013-01-01

    Creation of an aesthetically pleasing nipple plays a significant role in breast reconstruction as a determining factor in patient satisfaction. The goals for nipple reconstruction include minimal donor site morbidity and appropriate, long-lasting projection. Currently, the most popular techniques used are associated with a significant loss of projection postoperatively. Accordingly, the authors introduce the angel flap, which is designed to achieve nipple projection with lasting results. The lateral edges of the flap and the area surrounding the top of the nipple are de-epithelialized and the flaps are wrapped to create a nipple mound composed primarily of dermis. Decreasing the amount of fat within core of the nipple and enhancing dermal content promotes long-lasting projection. Furthermore, the incision pattern fits within a desired areolar size, preventing unnecessary superfluous extension of the incisions. Thus, the technique described herein achieves the goals of nipple reconstruction, including adequate and long-lasting projection, without extension of the lateral limb scars.

  16. Double papilla flap technique for dual purpose

    Directory of Open Access Journals (Sweden)

    P Mohan Kumar

    2012-01-01

    Full Text Available Marginal tissue recession exposes the anatomic root on the teeth, which gives rise to -common patient complaints. It is associated with sensitivity, tissue irritation, cervical abrasions, and esthetic concerns. Various types of soft tissue grafts may be performed when recession is deep and marginal tissue health cannot be maintained. Double papilla flap is an alternative technique to cover isolated recessions and correct gingival defects in areas of insufficient attached gingiva, not suitable for a lateral sliding flap. This technique offers the advantages of dual blood supply and denudation of interdental bone only, which is less susceptible to permanent damage after surgical exposure. It also offers the advantage of quicker healing in the donor site and reduces the risk of facial bone height loss. This case report presents the advantages of double papilla flap in enhancing esthetic and functional outcome of the patient.

  17. Mass media interventions to reduce help-seeking delay in people with symptoms of acute myocardial infarction: time for a new approach?

    Science.gov (United States)

    Caldwell, Mary A; Miaskowski, Christine

    2002-01-01

    Minimizing patient delay in seeking care for acute myocardial infarction (AMI) is important in the reduction of morbidity and mortality. However, mass media interventions to reduce these delays have had limited success. This paper critiques delay reducing intervention studies and draws on other public health campaigns to identify new directions. A Medline search for the years 1985 through 2000 yielded eight intervention studies meeting inclusion criteria. Three of eight studies reported successful interventions although two of three were only marginally successful. Most studies used similar messages. Campaign lengths, type of media, and sample sizes varied. High risk populations and those with confirmed MI responded more quickly. To reduce patient delay, media messages need to do more than create awareness. Future interventions should target high risk audiences, promote dialogue between previous AMI patients and high risk patients, address problems of denial, provide gender specific education, and emphasize symptom evaluation, problem solving, and decision-making skills.

  18. Skin-sparing mastectomy and immediate reconstruction with DIEP flap after breast-conserving therapy

    Science.gov (United States)

    Andree, Christoph; Munder, Beatrix; Seidenstuecker, Katrin; Richrath, Philipp; Behrendt, Philipp; Köppe, Tobias; Hagouan, Mazen; Audretsch, Werner; Nestle-Krämling, Carolin; Witzel, Christian

    2012-01-01

    Summary Background Currently about 70% of women who suffer from breast cancer undergo breast-conserving therapy (BCT) without removing the entire breast. Thus, this surgical approach is the standard therapy for primary breast cancer. If corrections are necessary, the breast surgeon is faced with irritated skin and higher risks of complications in wound healing. After radiation, an implant-based reconstruction is only recommended in selected cases. Correction of a poor BCT outcome is often only solved with an additional extended operation using autologous reconstruction. Material/Methods In our plastic surgery unit, which focuses on breast reconstruction, we offer a skin-sparing or subcutaneous mastectomy, followed by primary breast reconstruction based on free autologous tissue transfer to correct poor BCT outcomes. Between July 2004 and May 2011 we performed 1068 deep inferior epigastric artery perforator (DIEP) flaps for breast reconstruction, including 64 skin-sparing or subcutaneous mastectomies, followed by primary DIEP breast reconstruction procedures after BCT procedures. Results In all free flap-based breast reconstruction procedures, we had a total flap loss in 0.8% (9 cases). Within the group of patients after BCT, we performed 41 DIEP flaps and 23 ms-2 TRAM flaps after skin-sparing or subcutaneous mastectomies to reconstruct the breast. Among this group we had of a total flap loss in 1.6% (1 case). Conclusions In cases of large tumour sizes and/or difficult tumour locations, the initial oncologic breast surgeon should inform the patients of a possibly poor cosmetic result after BCT and radiation. In our opinion a skin-sparing mastectomy with primary breast reconstruction should be discussed as a valid alternative. PMID:23197233

  19. Reconstruction after Anterior Chest Wall Keloid Resection Using Internal Mammary Artery Perforator Propeller Flaps

    Science.gov (United States)

    Ogawa, Rei; Ono, Shimpei; Akaishi, Satoshi; Dohi, Teruyuki; Iimura, Takeshi; Nakao, Junichi

    2016-01-01

    Background: It is difficult to completely resect huge anterior chest wall keloids and then close the wound directly. We report here our retrospective analysis of our case series of patients with such keloids who underwent reconstruction with internal mammary artery perforator (IMAP) pedicled propeller flaps and then received postoperative high-dose-rate superficial brachytherapy. Methods: All consecutive patients with large/severe keloids on the anterior chest wall who underwent keloid resection followed by reconstruction with IMAP-pedicled propeller flaps and then high-dose-rate superficial brachytherapy in our academic hospital were identified. All cases were followed for >18 months. Donor site position, perforator pedicle, flap size, angle of flap rotation, complications, and recurrence were documented. Results: There were nine men and one woman. The average age was 37.9 years. The average follow-up duration was 28.7 months. The largest flap was 16 × 4 cm. The dominant perforators of the internal mammary artery were located in the sixth (n = 2), seventh (n = 5), eighth (n = 1), and ninth (n = 2) intercostal spaces. Twelve months after surgery, patients reported marked relief from keloid-associated pain and itching, except in two patients who underwent partial keloid resection; their remaining keloids were still troublesome but after conservative therapies, including steroid ointments/plasters, the keloids gradually ameliorated. Eighteen months after surgery, there was no keloid recurrence or new development of keloids on the donor site. Conclusions: IMAP-pedicled propeller flaps transfer skin tension from the anterior chest wall to the abdomen. Our series suggests that this approach combined with radiation therapy can control keloid recurrence.

  20. [Reconstruction of full-thickness nasal alar defect with combined nasolabial flap and free auricular composite flap].

    Science.gov (United States)

    Peng, Weihai; Rong, Li; Wang, Wangshu; Liu, Chao; Zhang, Duo

    2014-05-01

    To investigate the technique and its effect of combined nasolabial flap and free auricular composite flap for full-thickness nasal alar defect. From March 2010 to March 2013, 9 patients with full-thickness nasal alar defects were treated with combined nasolabial flaps and free auricular composite flaps. Composite auricular flap was used as inner lining and cartilage framework. The nasolabial flap at the same side was used as outer lining. All the patients were followed up for 6-18 months (average, 12 months). All the 9 composite auricular flaps survived completely. Epidermal necrosis happened at the distal end of 1 nasolabial flap. Alar rim was almost normal and symmetric nose was achieved in 6 cases. The arc and the thickness of the alar rim was not enough in 3 cases, resulting in asymmetric appearance. The survival area of auricular composite flap can be enlarged with nasolabial flap. The auricular helix edge can be reserved to reconstruct nasal alar rim with smooth and natural arc. Large full-thickness nasal alar defedts can be reconstructed with combined nasolabial flaps and free auricular composite flaps.

  1. Perforator anatomy of the radial forearm free flap versus the ulnar forearm free flap for head and neck reconstruction

    NARCIS (Netherlands)

    Hekner, D.D.; Roeling, TAP; van Cann, EM

    2016-01-01

    The aim of this study was to investigate the vascular anatomy of the distal forearm in order to optimize the choice between the radial forearm free flap and the ulnar forearm free flap and to select the best site to harvest the flap. The radial and ulnar arteries of seven fresh cadavers were injecte

  2. Delayed fluorescence in photosynthesis.

    Science.gov (United States)

    Goltsev, Vasilij; Zaharieva, Ivelina; Chernev, Petko; Strasser, Reto J

    2009-01-01

    Photosynthesis is a very efficient photochemical process. Nevertheless, plants emit some of the absorbed energy as light quanta. This luminescence is emitted, predominantly, by excited chlorophyll a molecules in the light-harvesting antenna, associated with Photosystem II (PS II) reaction centers. The emission that occurs before the utilization of the excitation energy in the primary photochemical reaction is called prompt fluorescence. Light emission can also be observed from repopulated excited chlorophylls as a result of recombination of the charge pairs. In this case, some time-dependent redox reactions occur before the excitation of the chlorophyll. This delays the light emission and provides the name for this phenomenon-delayed fluorescence (DF), or delayed light emission (DLE). The DF intensity is a decreasing polyphasic function of the time after illumination, which reflects the kinetics of electron transport reactions both on the (electron) donor and the (electron) acceptor sides of PS II. Two main experimental approaches are used for DF measurements: (a) recording of the DF decay in the dark after a single turnover flash or after continuous light excitation and (b) recording of the DF intensity during light adaptation of the photosynthesizing samples (induction curves), following a period of darkness. In this paper we review historical data on DF research and recent advances in the understanding of the relation between the delayed fluorescence and specific reactions in PS II. An experimental method for simultaneous recording of the induction transients of prompt and delayed chlorophyll fluorescence and decay curves of DF in the millisecond time domain is discussed.

  3. Internal Limiting Membrane Flap Techniques for the Repair of Large Macular Holes: a Short-Term Follow-up of Anatomical and Functional Outcomes.

    Science.gov (United States)

    Guber, J; Lang, C; Valmaggia, C

    2017-02-01

    Background To evaluate the technique of inverted internal limiting membrane (ILM) flaps for the management of large macular holes and autologous ILM free flaps for non-closing macular holes. Patients and methods All macular holes were treated with pars plana vitrectomy and dual blue assisted ILM flap technique. The inverted ILM flap was created as a primary procedure for large macular holes (diameter > 400 µm). On the other hand, the free ILM flap technique was used as a secondary procedure for non-closing macular holes after failed initial standard procedure. SD-OCT images were taken to assess the anatomical outcome of surgery, while best corrected visual acuity (BCVA) was used to evaluate the functional outcome during a 2-month follow-up. Results All patients underwent successful planned manipulation of the ILM flap. In seven patients/eyes, an inverted ILM flap was created, in three patients/eyes a free ILM flap translocation was performed. All patients achieved complete anatomical closure. Partial microstructural reconstruction, demonstrated on SD-OCT as restoration of the external limiting membrane and the ellipsoid zone, was observed in some cases as early as one month after surgery. Functionally, in comparison to baseline, most of the patients showed improvements in BCVA of 1 to 2 lines at the first postoperative follow-up visit. Conclusions Inverted ILM flaps for large macular holes and free flaps for non-closing macular holes appear to be a safe and effective approach, with favourable short-term anatomical and functional results.

  4. The transversely split gracilis twin free flaps

    Directory of Open Access Journals (Sweden)

    Upadhyaya Divya

    2010-01-01

    Full Text Available The gracilis muscle is a Class II muscle that is often used in free tissue transfer. The muscle has multiple secondary pedicles, of which the first one is the most consistent in terms of position and calibre. Each pedicle can support a segment of the muscle thus yielding multiple small flaps from a single, long muscle. Although it has often been split longitudinally along the fascicles of its nerve for functional transfer, it has rarely been split transversely to yield multiple muscle flaps that can be used to cover multiple wounds in one patient without subjecting him/her to the morbidity of multiple donor areas .

  5. Delay-Dependent Observers for Uncertain Nonlinear Time-Delay Systems

    Directory of Open Access Journals (Sweden)

    Dongmei Yan

    2013-05-01

    Full Text Available This paper is concerned with the observer design problem for a class of discrete-time uncertain nonlinear systems with time-varying delay. The nonlinearities are assumed to satisfy global Lipschitz conditions which appear in both the state and measurement equations. The uncertainties are assumed to be time-varying but norm-bounded. Two Luenberger-like observers are proposed. One is delay observer and the other is delay-free observer. The delay observer which has an internal time delay is applicable when the time delay is known. The delay-free observer which does not use delayed information is especially applicable when the time delay is not known explicitly. Delay-dependent conditions for the existences of these two observers are derived based on Lyapunpv functional approach. Based on these conditions, the observer gains are obtained using the cone complementarity linearization algorithm. Finally, a numerical example is given to illustrate the effectiveness of the proposed method.

  6. Pre-expanded Intercostal Perforator Super-Thin Skin Flap.

    Science.gov (United States)

    Liao, Yunjun; Luo, Yong; Lu, Feng; Hyakusoku, Hiko; Gao, Jianhua; Jiang, Ping

    2017-01-01

    This article introduces pre-expanded super-thin intercostal perforator flaps, particularly the flap that has a perforator from the first to second intercostal spaces. The key techniques, advantages and disadvantages, and complications and management of this flap are described. At present, the thinnest possible flap is achieved by thinning the pre-expanded flap that has a perforator from the first to second intercostal spaces. It is used to reconstruct large defects on the face and neck, thus restoring function and cosmetic appearance. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Fascia-only anterolateral thigh flap for extremity reconstruction.

    Science.gov (United States)

    Fox, Paige; Endress, Ryan; Sen, Subhro; Chang, James

    2014-05-01

    The ability to use the anterolateral thigh (ALT) flap as a vascularized fascial flap, without skin or muscle, was first documented by Koshima et al in 1989. The authors mention the possibility of using the fascia alone for dural reconstruction. Despite its description more than 20 years ago, little literature exists on the application of the ALT flap as a vascularized fascial flap. In our experience, the ALT flap can be used as a fascia-only flap for thin, pliable coverage in extremity reconstruction. After approval from the institutional review board, the medical records and photographs of patients who had undergone fascia-only ALT free flaps for extremity reconstruction were reviewed. Photographic images of patients were then matched to patients who had undergone either a muscle-only or a fasciocutaneous free flap reconstruction of an extremity. Photographs of the final reconstruction were then given to medical and nonmedical personnel for analysis, focusing on aesthetics including color and contour. Review of cases performed over a 2-year period demonstrated similar ease of harvest for fascia-only ALT flaps compared to standard fasciocutaneous ALT flaps. Fascia-only flaps were used for thin, pliable coverage in the upper and lower extremities. There was no need for secondary procedures for debulking or aesthetic flap revision. In contrast to muscle flaps, which require muscle atrophy over time to achieve their final appearance, there was a similar flap contour from approximately 1 month postoperatively throughout the duration of follow-up. When a large flap is required, the fascia-only ALT has the advantage of a single-line donor-site scar. Photograph comparison to muscle flaps with skin grafts and fasciocutaneous flaps demonstrated improved color, contour, and overall aesthetic appearance of the fascia-only ALT over muscle and fasciocutaneous flaps. The fascia-only ALT flap provides reliable, thin, and pliable coverage with improved contour and color over

  8. The study of expanded tri-lobed flap in a rabbit model: possible flap model in ear reconstruction?

    Directory of Open Access Journals (Sweden)

    Yüreklý Yakup

    2003-12-01

    Full Text Available Abstract Background Local flaps are widely used in reconstructive surgery. Tri-lobed skin flap is a relatively new flap and there has been no experimental model of this flap. This flap can be used for repair of full thickness defects in the face, ears and alar region. Based on the size of ears in a rabbit, we designed a model of ear reconstruction using expanded tri-lobed flap. Local flaps are more advantageous in that they provide excellent color and texture matching up with those of the face, adequately restore ear contour, place scars in a favorable location and ideally accomplish these goals in a single stage with minimal donor site morbidity. Methods Eight adult New Zealand rabbits were divided into two groups. 50 ml round tissue expander were implanted to four rabbits. After completion of the expansion, a superiorly based tri-lobed flap was elevated and a new ear was created from the superior dorsal skin of each rabbit. Scintigraphy with Technetium-99m pertecnetate was performed to evaluate flap viability. Results Subtotal flap necrosis was seen in all animals in non-expanded group. New ear in dimensions of the original ear was created in expanded group without complication. Perfusion and viability of the flaps were proved by Technetium-99m pertecnetate scintigraphy. Conclusion According to our knowledge this study is the first to demonstrate animal model in tri-lobed flap. Also, our technique is the first application of the trilobed flap to the possible ear reconstruction. We speculated that this flap may be used mastoid based without hair, in human. Also, tri-lobed flap may be an alternative in reconstruction of cylindrical organs such as penis or finger.

  9. Perforator-based fasciocutaneous flap for pressure sore reconstruction.

    Science.gov (United States)

    Lin, Chih-Hsun; Ma, Hsu

    2012-12-01

    Pressure sore reconstruction is always a challenge for plastic surgeons due to its high recurrence rate. In addition to the myocutaneous flap, the perforator-based fasciocutaneous flap has become a new entity used for pressure sore reconstruction. This study presents a series of 26 perforator-based fasciocutaneous flaps for pressure sore reconstruction, with good outcomes in 21 patients from July 2008 to April 2011. The flaps were advanced, transposed, or rotated to obliterate the defects. Twenty of 26 flaps healed uneventfully without complication. One patient had a flap that totally necrosed, one had partial flap necrosis (flap rotated 180° in the above two cases), one had infection and healed by a secondary flap, one had minor wound dehiscence, one died of pneumonia 1 week postoperatively, and recurrence developed in one patient. The perforator-based fasciocutaneous flap is a reliable method and produced good results in this series. These flaps are well vascularised, have enough soft tissue bulk, and have a high degree of mobilisation freedom.

  10. Effect of Systemic Antioxidant Allopurinol Therapy on Skin Flap Survival

    Science.gov (United States)

    Rasti Ardakani, Mehdi; Al-Dam, Ahmed; Rashad, Ashkan; Shayesteh Moghadam, Ali

    2017-01-01

    BACKGROUND It has been reported that systemic administration of allopurinol improves cell survival. This study was aimed to evaluate effects of allopurinol on skin flaps in dogs. METHODS Twenty dogs underwent one skin flap surgery with a 2-week interval. The first procedure was performed according to the standard protocols. The second phase was started by a 1-week pretreatment with allopurinol. Length of the necrotic zone was measured and recorded daily. At each phase, flaps were removed and sent for histopathological study after 1 week observation. RESULTS Mean length of the necrotic zone in allopurinol treated skin flaps has been significantly less than normal flaps over all 7 days of observation (p<0.0001). Histopathology study showed less inflammation and more normal tissue structure in the allopurinol treated skin flaps. CONCLUSION It was demonstrated that systemic administration of allopurinol significantly improved skin flap survival. PMID:28289614

  11. Breast reconstruction by pedicled transverse rectus abdominis myocutaneous flap

    Directory of Open Access Journals (Sweden)

    Kozarski Jefta

    2004-01-01

    Full Text Available Reconstruction of the amputated breast in female patients after surgical management of breast carcinoma is possible with the use of autologous tissue, synthetic implants, or by combining autologous tissue and synthetic materials. Autologous tissue provides soft and sufficiently elastic tissue which is usable for breast reconstruction and eventually obtains original characteristics of the surrounding tissue on the chest wall. The use of the TRAM flap for breast reconstruction was introduced in 1982 by Hartrampf Scheflan, and Black. The amount of the TRAM flap tissue allows breast reconstruction in the shape most adequate to the remaining breast. The possibilities of using the TRAM flap as pedicled myocutaneous flap or as free TRAM flap make this flap a superior choice for breast reconstruction in comparison with other flaps.

  12. Functional results of microvascular reconstruction after hemiglossectomy: free anterolateral thigh flap versus free forearm flap

    OpenAIRE

    TARSITANO, A.; VIETTI, M.V.; Cipriani, R; MARCHETTI, C.

    2013-01-01

    SUMMARY The aim of the present study is to assess functional outcomes after hemiglossectomy and microvascular reconstruction. Twenty-six patients underwent primary tongue microvascular reconstruction after hemiglossectomy. Twelve patients were reconstructed using a free radial forearm flap and 14 with an anterolateral thigh flap. Speech intelligibility, swallowing capacity and quality of life scores were assessed. Factors such as tumour extension, surgical resection and adjuvant radiotherapy ...

  13. Dorsalis Pedis Free Flap: The Salvage Option following Failure of the Radial Forearm Flap in Total Lower Lip Reconstruction

    OpenAIRE

    Theodoros Stathas; Georgios Tsinias; Dimitra Tsiliboti; Aris Tsiros; Nicholas Mastronikolis; Panos Goumas

    2014-01-01

    Reconstruction after resection of large tumors of the lower lip requires the use of free flaps in order to restore the shape and the function of the lip, with the free radial forearm flap being the most popular. In this study we describe our experience in using the dorsalis pedis free flap as a salvage option in reconstruction of total lower lip defect in a patient with an extended lower lip carcinoma after failure of the radial forearm free flap, that was initially used. The flap was integra...

  14. Enhanced Correlation of SMART Active Flap Rotor Loads

    Science.gov (United States)

    Kottapalli, Sesi

    2011-01-01

    This is a follow-on study to a 2010 correlation effort. Measured data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. As background, during the wind tunnel test, unexpectedly high inboard loads were encountered, and it was hypothesized at that time that due to changes in the flexbeams over the years, the flexbeam properties used in the analysis needed updating. Boeing Mesa, recently updated these properties. This correlation study uses the updated flexbeam properties. Compared to earlier studies, the following two enhancements are implemented: i) the inboard loads (pitchcase and flexbeam loads) correlation is included for the first time (reliable prediction of the inboard loads is a prerequisite for any future anticipated flight-testing); ii) the number of blade modes is increased to better capture the flap dynamics and the pitchcase-flexbeam dynamics. Also, aerodynamically, both the rolled-up wake model and the more complex, multiple trailer wake model are used, with the latter slightly improving the blade chordwise moment correlation. This sensitivity to the wake model indicates that CFD is needed. Three high-speed experimental cases, one uncontrolled free flap case and two commanded flap cases, are considered. The two commanded flap cases include a 2o flap deflection at 5P case and a 0o flap deflection case. For the free flap case, selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the commanded 2o flap case, the experimental flap variation is approximately matched by increasing the analytical flap hinge stiffness. This increased flap hinge stiffness is retained for the commanded 0o flap case also, which is treated as a free flap case, but with larger flap hinge stiffness. The change in the mid-span and outboard loads correlation due to the updating of the flexbeam properties is not significant. Increasing the number of blade modes results in an

  15. Composite mesh and gluteal fasciocutaneous rotation flap for perineal hernia repair after abdominoperineal resection: a novel technique.

    Science.gov (United States)

    Papadakis, Marios; Hübner, Gunnar; Bednarek, Marzena; Arafkas, Mohamed

    2017-03-01

    Perineal hernia is an uncommon complication following abdominoperineal rectum resection. Several surgical procedures have been proposed for perineal hernia repair, including perineal, laparoscopic and abdominal approaches. Repair techniques can be classified into primary suture techniques, mesh placements and repairs with autogenous tissue. We report a 68-year-old man with a perineal hernia, who underwent a pelvic floor reconstruction with a transperineal composite mesh and a gluteal fasciocutaneous rotation flap. We conclude that a combined approach with transperineal mesh reconstruction and gluteal fasciocutaneous flap could be an alternative choice in perineal hernia repair after abdominoperineal resection.

  16. Microsurgery flap in endodontic surgery: case report.

    Science.gov (United States)

    Cecchetti, F; Ricci, S; DI Giorgio, G; Pisacane, C; Ottria, L

    2009-01-01

    In periodontal plastic surgery it is increasingly more evident the relavance of the protection of the gingival marginal anatomy through the realization of a conservative flap. Minimizing the recession of the treated tissue. A correct healing always needs to take into account the diameter and type of the suture and the time of removal from the wound.

  17. Pearls for perfecting the mastoid interpolation flap.

    Science.gov (United States)

    Justiniano, Hilda; Eisen, Daniel B

    2009-06-15

    Helical rim ear defects can present a reconstructive challenge to the Mohs surgeon. Multiple options exist including wedge excision, helical rim advancement flaps, bilobed flap, and grafts, to name a few. Wedge excision of the ear may result in a noticeable anteverted, smaller ear, and disrupts auricular cartilage with the possibility of chondritis and excess pain. Helical rim advancements can result in anteversion of the ear and a smaller lobule. Mastoid interpolation flaps, which are also called retroauricular to auricular flaps, can be a useful alternative in patients who are willing to return for a second procedure. They are easy to perform and can result in a highly aesthetic reconstruction in which the ear size and form are maintained. The donor skin comes from an area that is hidden from view and heals with minimal complications. We present our suggestions for performing these reconstructions. Ways to optimize results, potential pitfalls, and postoperative care instructions are discussed. Step by step videos are included with this manuscript.

  18. Flapping wing aerodynamics: from insects to vertebrates.

    Science.gov (United States)

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.

  19. Delayed childbearing.

    Science.gov (United States)

    Francis, H H

    1985-06-01

    In many Western nations, including England and Wales, Sweden, and the US, there is a current trend towards delayed childbearing because of women's pursuit of a career, later marriage, a longer interval between marriage and the 1st birth, and the increasing number of divorcees having children in a 2nd marriage. Wives of men in social classes I and II in England and Wales are, on average, having their 1st child at 27.9 years, 1.6 years later than in 1973, and in social classes IV and V, 1.0 years later than in 1973, at a mean age of 23.7 years. Consequently, the total period fertility rate for British women aged 30-34 years, 35-39 years, and 40 and over increased by 4%, 2%, and 4%, respectively, between 1982-83, in contrast to reductions of 2% and 3%, respectively, in the 15-19 year and 20-24 year age groups, with the 25-29-year-olds remaining static. The average maternal mortality for all parties in England and Wales during 1976-78 was 106/million for adolescents, 70.4/million for 20-24 year-olds, and 1162/million for those aged 40 years and older. The specific obstetric and allied conditions which increase with age are the hypertensive diseases of pregnancy, hemorrhage, pulmonary embolism, abortion, cardiac disease, caesarean section, ruptured uterus, and amniotic fluid embolism. The Swedish Medical Birth Registry of all live births and perinatal deaths since 1973 has shown that the risk of late fetal death is significantly greater in women aged 30-39 years than in those of the same parity and gravidity aged 20-24 years. The risk of giving birth to low birth weight babies preterm and at term and of premature labor are similarly increased. The early neonatal death rate also was increased for primigravidas and nulliparas in the 30-39 year age group but not in parous women. This is, in part, due to the rise in incidence of fetal abnormalities with advancing maternal age because of chromosomal and nonchromosomal anomalies. These also appear to be the cause of the

  20. [Vestibularly displaced flap with bone augmentation].

    Science.gov (United States)

    Bakalian, V L

    2009-01-01

    The aim of this study is to achieve esthetic gingival contours with the help of less traumatic mucogingival surgeries. 9 Patients were operated with horizontal deficiencies in 9 edentulous sites, planned to be restored with fixed partial dentures. In all cases there was lack of keratinized tissues. Temporary bridges were fabricated to all patients. Before surgery the bridges were removed and the abutment teeth were additionally cleaned with ultrasonic device. A horizontal incision was made from lingual (palatal) side between the abutment teeth, which was connected with two vertical releasing incisions to the mucogingival junction from the vestibular side. The horizontal incision was made on a distance 6-10 mm from the crest of the alveolar ridge. A partial thickness flap in the beginning 3-5 mm, then a full thickness flap up to the mucogingival junction, then a partial thickness flap was made. The flap was mobilized and displaced vestibularly. In the apical part the cortical bone was perforated, graft material was put and the flap was sutured. In all 9 cases the horizontal defect was partially or fully eliminated. The width of the keratinized tissues was also augmented in all cases. The postoperative healing was without complications, discomfort and painless. The donor sites also healed without complications. The application of Solcoseryl Dental Adhesive Paste 3 times a day for 7-10 days helped for painless healing of the donor site. The offered method of soft tissue and bone augmentation is effective in the treatment of horizontal defects of edentulous alveolar ridges of not big sizes. It makes possible to achieve esthetic results without traumatizing an additional donor-site.

  1. Recurrent squamous cell carcinoma of the scalp treated with serial free flaps

    DEFF Research Database (Denmark)

    Ikander, Peder; Sørensen, Jens Ahm

    2015-01-01

    dorsi flaps and one anterolateral thigh flap. No total flap loss was seen, but partial flap necrosis called for secondarily reconstruction. The final result was cosmetically acceptable and the patient is of good health. In conclusion, serial free microvascular flaps may be used with good results when...

  2. Reconstruction of the anterior floor of the mouth with the inferiorly based nasolabial flap

    NARCIS (Netherlands)

    van Wijk, MP; Damen, A; Nauta, JM; Lichtendahl, DHE; Dhar, BK

    2000-01-01

    The results of reconstruction of the anterior floor of the mouth, using 105 nasolabial flaps in 79 patients were reviewed in a retrospective study. Of those flaps, 82% healed uneventfully; flap survival was 95%. Considerable flap loss occurred in 5%. Primary dehiscence was observed in 5% of all flap

  3. Delay Variation Model with Two Service Queues

    Directory of Open Access Journals (Sweden)

    Filip Rezac

    2010-01-01

    Full Text Available Delay in VoIP technology is very unpleasant issue and therefore a voice packets prioritization must be ensured. To maintain the high call quality a maximum information delivery time from the sender to the recipient is set to 150 ms. This paper focuses on the design of a mathematical model of end-to-end delay of a VoIP connection, in particular on a delay variation. It describes all partial delay components and mechanisms, their generation, facilities and mathematical formulations. A new approach to the delay variation model is presented and its validation has been done by experimention.

  4. The use of supraclavicular free flap with vascularized lymph node transfer for treatment of lymphedema: A prospective study of 100 consecutive cases.

    Science.gov (United States)

    Mardonado, Andres A; Chen, Ru; Chang, David W

    2017-01-01

    Vascularized lymph node transfer (VLNT) is gaining popularity for treatment of lymphedema. The purpose of this study was to evaluate the flap and the donor site morbidity of the supraclavicular (SC) VLNT. A review of a prospective database was performed for patients who had undergone SC VLNT to treat upper or lower extremity lymphedema. Flap and donor site complications were registered for each patient. A detailed technical surgical approach is explained. One hundred consecutive patients with lower or upper extremity lymphedema underwent SC VLNT (84% from the right side) with a mean of 11-months follow-up (range 3-19 months). There were no flap loss but three flaps (3%) required re-exploration due to venous congestion of the skin paddle. Two patients had local infection and three patients developed chyle leak (3%) at the donor site but resolved spontaneously. No donor site secondary lymphedema was noted. This is the largest prospective series of SC free flap VLNT for treatment of lymphedema. Low flap and donor site morbidity makes this flap an appealing source of lymph node transfer for lymphedema treatment. J. Surg. Oncol. 2017;115:68-71. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  5. Radical Surgical Excision and Use of Lateral Thoracic Flap for Intractable Axillary Hidradenitis Suppurativa

    Directory of Open Access Journals (Sweden)

    Wan-Lin Teo

    2012-11-01

    Full Text Available Current treatments for hidradenitis suppurativa (HS include prolonged courses of antibiotics,retinoids, immunosuppressants, and biologics. Severe cases that are resistant to prolongedmedical treatment pose a therapeutic challenge. We propose radical excision and lateral thoracicflap reconstruction as a treatment option for such cases. In our experience with two patients,good aesthetic and functional outcomes were achieved, with a high level of patient satisfaction.The availability of suitable flap coverage allows for wide resection of all of the hair-bearing skin,leading to a low incidence of residual disease and subsequent recurrence. Following excisionof the affected tissue, the ideal reconstructive method in the axilla provides suitable coveragewithout unacceptable donor site morbidity and also avoids axillary contractures. A long lateralthoracic flap with delay has excellent coverage with minimal donor tissue sacrifice. With asuitable flap coverage option, the management paradigm of intractable HS should shift fromprolonged medical treatment to allow decisive radical excision, which will improve the qualityof life for patients.

  6. Investigation of Body-involved Lift Enhancement in Bio-inspired Flapping Flight

    Science.gov (United States)

    Wang, Junshi; Liu, Geng; Ren, Yan; Dong, Haibo

    2016-11-01

    Previous studies found that insects and birds are capable of using many unsteady aerodynamic mechanisms to augment the lift production. These include leading edge vortices, delayed stall, wake capture, clap-and-fling, etc. Yet the body-involved lift augmentation has not been paid enough attention. In this work, the aerodynamic effects of the wing-body interaction on the lift production in cicada and hummingbird forward flight are computationally investigated. 3D wing-body systems and wing flapping kinematics are reconstructed from the high-speed videos or literatures to keep their complexity. Vortex structures and associated aerodynamic performance are numerically studied by an in-house immersed-boundary-method-based flow solver. The results show that the wing-body interaction enhances the overall lift production by about 20% in the cicada flight and about 28% in the hummingbird flight, respectively. Further investigation on the vortex dynamics has shown that this enhancement is attributed to the interactions between the body-generated vortices and the flapping wings. The output from this work has revealed a new lift enhancement mechanism in the flapping flight. This work is supported by NSF CBET-1313217 and AFOSR FA9550-12-1-0071.

  7. Basin stability in delayed dynamics

    Science.gov (United States)

    Leng, Siyang; Lin, Wei; Kurths, Jürgen

    2016-02-01

    Basin stability (BS) is a universal concept for complex systems studies, which focuses on the volume of the basin of attraction instead of the traditional linearization-based approach. It has a lot of applications in real-world systems especially in dynamical systems with a phenomenon of multi-stability, which is even more ubiquitous in delayed dynamics such as the firing neurons, the climatological processes, and the power grids. Due to the infinite dimensional property of the space for the initial values, how to properly define the basin’s volume for delayed dynamics remains a fundamental problem. We propose here a technique which projects the infinite dimensional initial state space to a finite-dimensional Euclidean space by expanding the initial function along with different orthogonal or nonorthogonal basis. A generalized concept of basin’s volume in delayed dynamics and a highly practicable calculating algorithm with a cross-validation procedure are provided to numerically estimate the basin of attraction in delayed dynamics. We show potential applicabilities of this approach by applying it to study several representative systems of biological or/and physical significance, including the delayed Hopfield neuronal model with multistability and delayed complex networks with synchronization dynamics.

  8. Reconstruction of the tongue and mouth floor with the myofascial vastus lateralis free flap after cancer ablation.

    Science.gov (United States)

    Wang, L; Liu, K; Shao, Z; Shang, Z-J

    2016-08-01

    The current study was undertaken to evaluate a novel approach to tongue and mouth floor reconstruction using the myofascial vastus lateralis free flap (MVLF). The surgical techniques, benefits, complication rate, and the aesthetic and functional results are described. A series of six patients underwent functional tongue reconstruction between July 2013 and November 2014. The myofascial vastus lateralis flap was obtained as follows: the vastus lateralis muscle was exposed, the neurovascular pedicle was identified, and the myofascial flap was raised. Postoperatively, the neotongue appeared plump and was able to maintain palatal contact. Moreover, no obvious decrease in flap volume was observed during the follow-up period. Most patients experienced good tongue mobility. Further use of the MVLF should confirm whether the mucous membrane on the surface of the flap becomes part of the tongue mucosa in the true sense, whether and how well the patients will recover their sense of taste, and the degree to which quality of life is improved after nerve anastomosis. So far, it appears to be a suitable approach to tongue and mouth floor reconstruction.

  9. Variable-delay feedback control of unstable steady states in retarded time-delayed systems

    CERN Document Server

    Gjurchinovski, Aleksandar; 10.1103/PhysRevE.81.016209

    2010-01-01

    We study the stability of unstable steady states in scalar retarded time-delayed systems subjected to a variable-delay feedback control. The important aspect of such a control problem is that time-delayed systems are already infinite-dimensional before the delayed feedback control is turned on. When the frequency of the modulation is large compared to the system's dynamics, the analytic approach consists of relating the stability properties of the resulting variable-delay system with those of an analogous distributed delay system. Otherwise, the stability domains are obtained by a numerical integration of the linearized variable-delay system. The analysis shows that the control domains are significantly larger than those in the usual time-delayed feedback control, and that the complexity of the domain structure depends on the form and the frequency of the delay modulation.

  10. Simulation Study of Flap Effects on a Commercial Transport Airplane in Upset Conditions

    Science.gov (United States)

    Cunningham, Kevin; Foster, John V.; Shah, Gautam H.; Stewart, Eric C.; Ventura, Robin N.; Rivers, Robert A.; Wilborn, James E.; Gato, William

    2005-01-01

    As part of NASA's Aviation Safety and Security Program, a simulation study of a twinjet transport airplane crew training simulation was conducted to address fidelity for upset or loss of control conditions and to study the effect of flap configuration in those regimes. Piloted and desktop simulations were used to compare the baseline crew training simulation model with an enhanced aerodynamic model that was developed for high-angle-of-attack conditions. These studies were conducted with various flap configurations and addressed the approach-to-stall, stall, and post-stall flight regimes. The enhanced simulation model showed that flap configuration had a significant effect on the character of departures that occurred during post-stall flight. Preliminary comparisons with flight test data indicate that the enhanced model is a significant improvement over the baseline. Some of the unrepresentative characteristics that are predicted by the baseline crew training simulation for flight in the post-stall regime have been identified. This paper presents preliminary results of this simulation study and discusses key issues regarding predicted flight dynamics characteristics during extreme upset and loss-of-control flight conditions with different flap configurations.

  11. Biomimetic bluff body drag reduction by self-adaptive porous flaps

    CERN Document Server

    Mazellier, Nicolas; Kourta, Azeddine

    2011-01-01

    The performances of an original passive control system based on a biomimetic approach are assessed by investigating the flow over a bluff-body. This control device consists in a couple of flaps made from the combination of a rigid plastic skeleton coated with a porous fabric mimicking the shaft and the vane of the bird's feathers, respectively. The sides of a square cylinder have been fitted with this system so as to enable the flaps to freely rotate around their leading edge. This feature allows the movable flaps to self-adapt to the flow conditions. Comparing both the uncontrolled and the controlled flow, a significant drag reduction (up to 22%) has been obtained over a broad range of Reynolds number. The investigation of the mean flow reveals a noticeable modification of the flow topology at large scale in the vicinity of the controlled cylinder accounting for the increase of the pressure base in comparison with the natural flow. Meanwhile, the study of the relative motion of both flaps points out that the...

  12. The changes in resting anal pressure after performing full-thickness rectal advancement flaps.

    Science.gov (United States)

    Balciscueta, Zutoia; Uribe, Natalia; Mínguez, Miguel; García-Granero, Eduardo

    2017-09-01

    Advancement flap is an accepted approach for treating complex fistula-in-ano.The purpose was to evaluate the changes in resting pressure along the anal canal after performing a full-thickness flap. Manometric review of patients who have undergone a full-thickness rectal advancement flap procedure for complex anal fistulas of cryptoglandular origin. Recurrence and continence were evaluated. Resting Anal Pressure was assessed along the anal canal by two measures: maximum resting pressure(MRP) and inferior resting pressure(IRP) at 0.5 cm from the anal verge. 119 patients were evaluated. Overall recurrence rate was5.9%. Anal continence was maintained intact in 76.5%. Manometric study showed a significant decrease in postoperative MRP(90.6 ± 31.9 to 45.2 ± 20 mmHg; p anal canal, due to the inclusion of the internal sphincter in flap. It seems crucial to preserve the distal internal sphincter intact as it helps both to maintain the resting pressure in the lower third and avoid deformities of the anal margin. Copyright © 2017 Elsevier Inc. All rights reserved.

  13. Technology of laser repair welding of nickel superalloy inner flaps of jet engine

    Directory of Open Access Journals (Sweden)

    A. Klimpel

    2011-07-01

    Full Text Available Purpose: of this paper: work out laser welding repair technology of cracked MIG 29 jet engine inner flaps made of cast nickel superalloy ŻS-3DK (ЖС-3ДК, Russian designation.Design/methodology/approach: The study were based on the analysis of laser HPDL powder INCONEL 625 welding of nickel superalloy using wide range of welding parameters to provide highest quality repair welds.Findings: Study of automatic welding technologies GTA, PTA and laser HPDL has shown that just laser welding can provide high quality repair welds. In order to establish the properties of welded joints repair cracks in the inner flap HPDL laser, studied the hardness, mechanical properties and erosive wear resistance.Research limitations/implications: It was found that only laser HPDL welding can provide high quality repair welds.Practical implications: The technology can be applied for repair cracked MIG 29 jet engine inner flaps.Originality/value: Repairing cracked MIG 29 jet engine inner flaps.

  14. Pedicle versus free flap reconstruction in patients receiving intraoperative brachytherapy.

    Science.gov (United States)

    Geiger, Erik J; Basques, Bryce A; Chang, Christopher C; Son, Yung; Sasaki, Clarence T; McGregor, Andrew; Ariyan, Stephan; Narayan, Deepak

    2016-08-01

    Introduction This study compared complication rates between pedicle flaps and free flaps used for resurfacing of intraoperative brachytherapy (IOBT) implants placed following head and neck tumour extirpation to help clarify the ideal reconstructive procedure for this scenario. Patients and methods A retrospective review of reconstructions with IOBT at our institution was conducted. Patient and treatment details were recorded, as were the number and type of flap complications, including re-operations. Logistic regressions compared complications between flap groups. Results Fifty free flaps and 55 pedicle flaps were included. On multivariate analysis, free flap reconstruction with IOBT was significantly associated with both an increased risk of having any flap complication (OR = 2.9, p = 0.037) and with need for operative revision (OR = 3.5, p = 0.048) compared to pedicle flap reconstruction. Conclusions In the setting of IOBT, free flaps are associated with an increased risk of having complications and requiring operative revisions.

  15. Effect of flapping trajectories on the dragonfly aerodynamics

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The effects of translational, figure-eight and double-figure-eight flapping trajectories on the dragonfly aerodynamics were numerically studied by solving the Navier-Stokes equations. There is a common characteristic regarding the lift/drag force coefficients that the downstroke flapping provides the lift forces while the upstroke flapping creates the thrust forces for different flapping trajectories. The maximum lift force coefficient exceeds five for the translational trajectory. It is greater than six for the figure-eight and double-figure-eight flapping trajectories, which is sufficiently larger than unity under the steady state flight condition. The ellipse and double-figure-eight flapping trajectories yield the decrease of the lift force, while the figure-eight flapping trajectory yields higher lift force as well as the thrust force than the translational flapping one. During the insect flight, the wing flapping status should be changed instantaneously to satisfy various requirements. Study of the flapping trajectories on the insect aerodynamics is helpful for the design of the Micro-air-vehicles (MAVs).

  16. Delay-dependent robust passivity control for uncertain time-delay systems

    Institute of Scientific and Technical Information of China (English)

    Li Guifang; Li Huiying; Yang Chengwu

    2007-01-01

    The robust passivity control problem is addressed for a class of uncertain delayed systems with timevarying delay. The parameter uncertainties are norm-bounded. First, the delay-dependent stability sufficient condition is obtained for the nominal system, and then, based-on the former, the delay-dependent robust passivity criteria is provided and the corresponding controller is designed in terms of linear matrix inequalities. Finally, a numerical example is given to demonstrate the validity of the proposed approach.

  17. A new flap alternative for trochanteric pressure sore coverage: distal gluteus maximus musculocutaneous advancement flap.

    Science.gov (United States)

    Nisanci, Mustafa; Sahin, Ismail; Eski, Muhitdin; Alhan, Dogan

    2015-02-01

    Management of long-term bedridden patients experiencing pressure sores still represents a surgical challenge due to limited flap alternatives and high recurrence rates after the treatment. Fasciocutaneous, musculocutaneous, local perforator-based flaps, and free flaps have all been used for treatment of trochanteric pressure sores. This study presents a new use of distal gluteus maximus (GM) muscle as an advancement musculocutaneous flap for coverage of trochanteric pressure sores in 7 patients. The technique involves design of a long V-shaped skin island over the distal fibers of the GM muscle, beginning from the inferoposterior wound edge and extending inferomedially, almost parallel to the gluteal crease. After its harvest as an island flap on the distal fibers of the GM muscle, the skin paddle can be advanced onto the trochanteric defect, whereas the muscle itself is rotated after severing its insertion to femur. If a second triangular skin island is designed on the proximal fibers of GM muscle to cover an associated sacral defect, 2 coexisting pressure sores can be reconstructed concomitantly with 2 skin paddles on a single muscle belly at 1 surgical setting. Of the 7 patients, 3 had 3 (bilateral trochanteric and sacral), 2 had 2 (sacral and trochanteric), and 2 had 1 (only trochanteric) pressure sores. All ulcers were closed successfully and all of the flaps survived totally without any complication except the one in which we experienced minimal wound dehiscence in the early postoperative period. Conclusively, our current surgical method provided a reliable coverage for trochanteric pressure sores although it was technically straightforward and fast. Additionally, it offers simultaneous closure of 2 pressure ulcers with 2 skin islands on a single muscle flap.

  18. Rib-sparing and internal mammary artery-preserving microsurgical breast reconstruction with the free DIEP flap.

    Science.gov (United States)

    Kim, Hyungsuk; Lim, So-Young; Pyon, Jai-Kyong; Bang, Sa-Ik; Oh, Kap Sung; Lee, Jeong Eon; Nam, Seok Jin; Mun, Goo-Hyun

    2013-03-01

    Using an internal mammary artery as the recipient vessel in a free flap autologous breast reconstruction is common practice, but this vessel is often sacrificed for end-to-end anastomosis and is typically assessed by removing a costal cartilage segment. The authors studied the reliability of the end-to-side arterial anastomosis using a rib-sparing approach by comparing it with end-to-end anastomosis. The authors analyzed 100 consecutive medical records of patients who underwent autologous breast reconstruction with a free deep inferior epigastric artery perforator flap in which the internal mammary vessels were assessed using a rib-sparing technique. The study compared the complications between the two groups of end-to-side arterial anastomosis (50 cases) and end-to-end arterial anastomosis (50 cases). Exposure of the internal mammary artery using a rib-sparing technique was performed successfully in all 100 flaps. The second and third intercostal spaces were used in 46 and 54 cases, respectively. The mean width of the used intercostal space was 18.3 ± 2.4 mm in the end-to-side group and 18.3 ± 2.9 mm in the end-to-end group (p = 0.923). All flaps survived without partial or total necrosis. One case of venous insufficiency that required exploration occurred in the end-to-side group; the flap was totally saved with venous revision. There was no significant statistical difference between the end-to-side and end-to-end groups in all other variables, including mean flap ischemic time (p = 0.431) and fat necrosis (p = 0.339). The rib-sparing and internal mammary artery-preserving free deep inferior epigastric artery perforator flap transfer is an efficient and safe technique for microsurgical breast reconstruction.

  19. Patient-specific reconstruction utilizing computer assisted 3D modelling for partial bone flap defect in hybrid cranioplasty

    Science.gov (United States)

    Hueh, Low Peh; Abdullah, Johari Yap; Abdullah, Abdul Manaf; Yahya, Suzana; Idris, Zamzuri; Mohamad, Dasmawati

    2016-12-01

    Autologous cranioplasty using a patient's original bone flap remain the commonest practice nowadays. However, partial bone flap defect is commonly encountered. Replacing the bone flap with pre-moulded synthetic bone flap is costly and not affordable to many patients. Hence most of the small to medium size defect was topped up with alloplastic material on a free hand basis intra-operatively which often resulted in inaccurate implant approximation with unsatisfactory cosmetic result. This study aims to evaluate implant accuracy and cosmetic outcome of cranioplasty candidates who underwent partial bone flap reconstruction utilising computer assisted 3D modelling. 3D images of the skull were obtained from post-craniectomy axial 1-mm spiral computed tomography (CT) scans and a virtual 3D model was generated using the Materialise Mimics software. The Materialise 3-Matic was then utilised to design a patient-specific implant. Prefabrication of the implant was performed by the 3D Objet printer, and a negative gypsum mold was created with the prefabricated cranial implant. Intraoperatively, a hybrid polymethyl methacrylate (PMMA)-autologous cranial implant was produced using the gypsum mold, and fit into the cranial defect. This study is still ongoing at the moment. To date, two men has underwent partial bone flap reconstruction utilising this technique and both revealed satisfactory implant alignment with favourable cosmesis. Mean implant size was 12cm2, and the mean duration of intraoperative reconstruction for the partial bone flap defect was 40 minutes. No significant complication was reported. As a conclusion, this new technique and approach resulted in satisfactory implant alignment and favourable cosmetic outcome. However, more study samples are needed to increase the validity of the study results.

  20. Temporal-based pericranial flaps for orbitofrontal Dural repair: A technical note and Review of the literature

    Directory of Open Access Journals (Sweden)

    Esther Dupépé

    2016-03-01

    Conclusions: A temporal-based pericranial flap represents an alternative vascularized pedicle flap to the classic frontal-based pericranial flap used in orbitofrontal dural repair. In certain clinical settings, the temporal-based flap may be preferable.