Implications of EMG channel count: enhancing pattern recognition online prosthetic testing.

Introduction: Myoelectric pattern recognition systems have shown promising control of upper limb powered prostheses and are now commercially available. These pattern recognition systems typically record from up to 8 muscle sites, whereas other control systems use two-site control. While previous offline studies have shown 8 or fewer sites to be optimal, real-time control was not evaluated. Methods: Six individuals with no limb absence and four individuals with a transradial amputation controlled a virtual upper limb prosthesis using pattern recognition control with 8 and 16 channels of EMG. Additionally, two of the individuals with a transradial amputation performed the Assessment for Capacity of Myoelectric Control (ACMC) with a multi-articulating hand and wrist prosthesis with the same channel count conditions. Results: Users had significant improvements in control when using 16 compared to 8 EMG channels including decreased classification error (p = 0.006), decreased completion time (p = 0.019), and increased path efficiency (p = 0.013) when controlling a virtual prosthesis. ACMC scores increased by more than three times the minimal detectable change from the 8 to the 16-channel condition. Discussion: The results of this study indicate that increasing EMG channel count beyond the clinical standard of 8 channels can benefit myoelectric pattern recognition users.

Strain-Enhanced Mobility of Monolayer MoS2.

Strain engineering is an important method for tuning the properties of semiconductors and has been used to improve the mobility of silicon transistors for several decades. Recently, theoretical studies have predicted that strain can also improve the mobility of two-dimensional (2D) semiconductors, e.g., by reducing intervalley scattering or lowering effective masses. Here, we experimentally show strain-enhanced electron mobility in monolayer MoS2 transistors with uniaxial tensile strain, on flexible substrates. The on-state current and mobility are nearly doubled with tensile strain up to 0.7%, and devices return to their initial state after release of the strain. We also show a gate-voltage-dependent gauge factor up to 200 for monolayer MoS2, which is higher than previous values reported for sub-1 nm thin piezoresistive films. These results demonstrate the importance of strain engineering 2D semiconductors for performance enhancements in integrated circuits, or for applications such as flexible strain sensors.

Wide Bandwidth and Low Driving Voltage Vented CMUTs for Airborne Applications.

This paper presents a novel method to increase the bandwidth (BW) of airborne capacitive micromachined ultrasonic transducers (CMUTs). This method introduces a gaseous squeeze film as a damping mechanism, which induces a stiffening effect that lowers the pull-in voltage and improves the sensitivity. The optimal behavior of this stiffening effect versus the damping mechanism can be controlled by creating optimized fluidic trenches of various heights within the gap. The fractional BW can be controlled from 0.89% to 8.1% by adjusting the trench height while lowering the pull-in voltage to less than 54 V at the gap height of 1.0 [Formula: see text]. To achieve the largest sensitivity and lowest pull-in voltage at a given BW, we have developed a multi-parameter optimization method to adjust all combinations of design parameters. A novel multiple hard-mask process flow has been developed to enable fabrication of CMUTs with different cavity and trench heights on the same wafer. These devices provided an equivalent noise pressure level of 4.77 µ Pa/ √ Hz with 6.24-kHz BW for 7.6- [Formula: see text] deep fluidic trenches and 4.88 µ Pa/ √ Hz with 7.48-kHz BW for 14.3- [Formula: see text] deep fluidic trenches. This demonstration of the wide-BW CMUTs with high sensitivity and low pull-in voltage makes them applicable to medical and thermoacoustic imaging, nondestructive testing, and ultrasonic flow metering.

Advances in Capacitive Micromachined Ultrasonic Transducers.

Capacitive micromachined ultrasonic transducer (CMUT) technology has enjoyed rapid development in the last decade. Advancements both in fabrication and integration, coupled with improved modelling, has enabled CMUTs to make their way into mainstream ultrasound imaging systems and find commercial success. In this review paper, we touch upon recent advancements in CMUT technology at all levels of abstraction; modeling, fabrication, integration, and applications. Regarding applications, we discuss future trends for CMUTs and their impact within the broad field of biomedical imaging.

Free tensor fasciae latae flap for abdominal wall reconstruction: overview and new innovation.

Extensive abdominal wall defects may result from tumor extirpation, traumatic injury, or soft tissue infections. Extensive traumatic injuries can often disrupt the soft tissue content of the abdomen as well as the bony support provided by the pelvis. Reconstruction of the lower abdomen should aim to recreate dynamic stability. Five patients with extensive lower abdominal wall disruption following traumatic injuries or infection were treated using a novel flap for functional reconstruction. We devised a free neurotized osteomyocutaneous tensor fasciae latae (TFL) flap that would restore bony continuity by providing a vascularized bone graft and simultaneously maintain the integrity of the attachment of the tensor fascia latae muscle to the iliac crest, reestablishing musculofascial continuity. A branch of the superior gluteal nerve was harvested with this composite flap and coapted to an intercostal nerve for reinnervation, thereby creating a dynamic muscle in these patients. All patients underwent successful free tissue reconstruction with 100% flap survival. The lower abdominal wall and bony integrity of the pelvis were successfully reconstructed. Reinnervation has shown clinical signs of maintained dynamic stability. The innervated TFL osteomyocutaneous flap is an ideal option for lower abdominal reconstruction in patients with complex abdominoperineal defects with loss of bony integrity.

Lateral breast flap with superomedial pedicle breast lift.

BACKGROUND: Single-stage, durable aesthetic contouring of the volume-depleted and ptotic breast remains a challenge for plastic and reconstructive surgeons. These challenges are often even more difficult in the patient who has undergone massive weight loss (MWL). OBJECTIVES: The authors describe their technique of reshaping the breasts of MWL patients with laterally-based breast flaps during a superomedial pedicle breast lift. METHODS: A total of 20 patients were treated in a private clinic by one of the authors between April 2006 and January 2010 were included in this study. Each patient underwent breast reshaping with mastopexy, lateral breast autoaugmentation, and implant insertion. A laterally-based breast flap was developed to augment the involuted and ptotic breast and was dissected in conjunction with the superomedial pedicle breast lift to maintain the implant position, prevent bottoming out, and provide tissue coverage between the skin and breast implant in the advent of wound breakdown. RESULTS: Mean follow-up for this patient series was 19.5 months (range, two to 47). The average patient age was 41 years (range, 21 to 56), and the majority of patients had Grade 2 ptosis (14 out of 20). The average volume of the implants in this study was 350 cc (range, 275 to 600). There were no instances of seroma or wound infection. Five patients had minor instances of wound breakdown, but none required surgical revision. One patient developed early capsular contracture and required revision. That same patient developed a small hematoma. Patient self-evaluation revealed a high level of satisfaction; all 20 patients reported being happy with their results. CONCLUSIONS: The laterally-based breast flap, in combination with the superomedial pedicle mastopexy, is a powerful tool for use in the postbariatric or postpartum patient in whom the majority of the breast parenchyma is needed to fill the skin envelope. This flap serves to improve overall breast shape by providing added tissue along the deficient inferior pole, relieving some of the unaesthetic lateral chest wall excess and providing an additional layer of support inferiorly along the fold.

Autogenous dorsal reconstruction: maximizing the utility of diced cartilage and fascia.

The problem of reconstructing the dorsum of the nose is complex and a source of frustration for both patients and surgeons. Dorsal deficiencies due to various etiologies and the need for dorsal contouring cause the plastic surgeon to look to time-honored techniques such as osseocartilaginous rib grafts while also searching for other options that may be less technically challenging and have the benefit of temporal success. Diced cartilage wrapped with deep temporal fascia is just such a method to achieve reliable dorsal reconstructions. The various ways to use diced cartilage and deep temporal fascia are discussed.

Delayed silicone breast implant infection with Mycobacterium avium-intracellulare.

Mycobacterial breast implant infection is a rare complication after augmentation mammaplasty. A review of the literature demonstrates multiple examples of breast implant infection with Mycobacterium fortuitum, but only rare discussion of Mycobacterium avium-intracellulare (MAC). The authors report an unusual case of MAC breast implant infection in a patient with a complex surgical history.

Saddle nose deformity: A new classification and treatment.

Treatment of saddle noses challenges the surgeon to provide esthetic form and functional improvement despite the presence of a limited amount of tissue to work with. The previous emphasis on alloplastic materials was a testament not only to the poor results obtained with autogenous tissues but also the unwarranted promise of the "miracles of modern chemistry." Only in the last 5 years have multiple surgeons begun to achieve outstanding results using autogenous tissues. It is hoped that this article will encourage younger surgeons to build on this foundation and provide hope to a group of patients who deserve our best efforts. Saddle nose and cleft lip nose deformity warrant a commitment to surgical excellence.

Cranial vault reduction cranioplasty in children with hydrocephalic macrocephaly.

Craniofacial surgeons are rarely presented patients with extreme hydrocephalic macrocephaly due to early diagnosis and treatment of the hydrocephalus. Macrocephaly can significantly limit or prohibit mobility, hygiene and can drastically change lifestyle and developmental issues. The authors herein report on four consecutive total cranial vault reduction cranioplasty procedures for correction of hydrocephalic macrocephaly. The patients had a reduction in cranial volume ranging from 111-641 mL. All patients survived the procedure. Improvement in head control and aesthetics were improved in all patients. All of the patients required at least one shunt revision following the procedure. We conclude that total cranial vault reshaping is safe and effective for the treatment of macrocephaly secondary to hydrocephalus.

Histological analysis of human diced cartilage grafts.

BACKGROUND: Grafting the radix and dorsum of the nose has been controversial and the plastic surgery community has recently revisited diced cartilage grafts. Previous articles by the authors reported clinical failures of diced cartilage-Surgicel-wrapped grafts and the successful implementation of diced cartilage-fascia-wrapped grafts for rhinoplasty procedures. This article investigates four means of radix and dorsum augmentation, including banked and fresh septum. METHODS: Twenty-seven human specimens were taken from rhinoplasty patients: six failed diced cartilage-Surgicel-wrapped grafts, eight diced cartilage-fascia-wrapped grafts, and 13 specimens of fresh cartilage or previously placed cartilage grafts. All were stained with hematoxylin and eosin, Masson's trichrome, safranin-O, glial fibrillary acidic protein, and Evans' van Gieson stains and analyzed for chondrocyte viability, matrix proteins, and regenerative potential of the cartilage. RESULTS: The diced cartilage-Surgicel-wrapped grafts showed disorganized fibrosis, loss of nuclei in chondrocyte lacunae, and negative glial fibrillary acidic protein staining. All specimens contained remnants of Surgicel and evidence of foreign body reaction. The diced cartilage-fascia-wrapped grafts showed normal histologic characteristics, healthy cartilage pieces with viable chondrocytes in their lacunae, positive glial fibrillary acidic protein staining, and organized capsule of fibrosis surrounding the cartilage pieces. The fascia was viable and showed an organized architecture distinctly different from the disorganized scar tissue of the diced cartilage-Surgicel-wrapped grafts. CONCLUSIONS: Given the histologic findings, diced cartilage-Surgicel-wrapped grafts absorbed due to foreign body reaction. Diced cartilage-fascia wrapped grafts survived and demonstrated normal cartilage viability. According to the clinical performance and analysis of these grafts, diced cartilage-fascia is the most reliable way to augment the nasal dorsum and radix with autologous diced cartilage.

Acquired unilateral coronal craniosynostosis.

Coronal craniosynostosis of both the sporadic and syndromic types have been comprehensively described and extensively investigated. Previously, there have been no cases reported of acquired unilateral coronal craniosynostosis. We present a case of a 22-month-old male who developed a left unilateral coronal craniosynostosis following multiple surgical interventions for birth-related intracranial injuries. The genesis and molecular biology of craniosynostosis are discussed; patient presentation and treatment are reviewed.

Survival of diced cartilage grafts: an experimental study.

BACKGROUND: Use of diced cartilage grafts in rhinoplasty surgery has recently undergone a dramatic resurgence. Some authors recommend wrapping diced cartilage with oxidized methylcellulose (i.e., Surgicel). Others prefer wrapping diced cartilage with autogenous deep temporal fascia. This study was designed to compare the behavior of diced cartilage grafts as an isolated entity or when wrapped with either Surgicel or deep temporal fascia. METHODS: Septal cartilage and deep temporal fascia were obtained from five patients in this institutional review board-approved study. The cartilage was diced into 0.5-mm pieces and implanted into subcutaneous dorsal skin pockets of Rowlett nude rats as isolated diced cartilage grafts, or wrapped in Surgicel or deep temporal fascia. Pieces of Surgicel and fascia were implanted alone as controls. The specimens were harvested at 8 weeks; processed by thin-section histology; stained with hematoxylin and eosin, Masson's trichrome, glial fibrillary acidic protein, safranin-O, and Evans van Gieson; and evaluated to determine cartilage viability and architectural characteristics. RESULTS: Diced cartilage wrapped in Surgicel yielded the lowest percentage viability and minimal staining with hematoxylin and eosin, trichrome tissue, safranin-O, and Evans van Gieson stains. Diced cartilage grafts wrapped in fascia had the greatest percentage of viable cartilage. The grafts wrapped in deep temporal fascia also demonstrated the strongest staining with the aforementioned stains. Differences in uptake of glial fibrillary acidic protein were not noticeable between the three groups. However, absolute numbers of nucleated lacunae and basophilic lacunae were significantly higher for grafts wrapped in deep temporal fascia. CONCLUSIONS: Diced cartilage grafts have reemerged as a viable method for nasal reconstruction in both primary and secondary rhinoplasty. Wrapping diced cartilage specimens contains the individual pieces and facilitates graft placement. Surgicel wraps appear to incite an inflammatory response and subsequent absorption of the cartilage. Fascia wraps appear to minimize inflammatory responses to the cartilage, thereby preserving healthy cartilage. This study demonstrates that deep temporal fascia is the preferred envelope with which to facilitate graft containment and maintain chondrocyte viability of diced cartilage grafts.