Search

Residual dissections after type A repairs are common and can result in aneurysm formation. Surgery is complex and considered high risk, particularly if there is arch involvement. A single-stage "arch-first" technique via clamshell incision is an excellent option in certain circumstances and herein we detail a variation of this approach using a trifurcated graft.

Diaphyseal malunion poses a great challenge for the orthopedic surgeon, and an inundation of morbidity for the patient. Diaphyseal malunion can cause altered gait, adjacent joint osteoarthritis and body dissatisfaction. This problem is fraught with complications without surgical intervention. There is a myriad of options for the management of a diaphyseal malunion. The clamshell osteotomy was engendered to ameliorate the difficulty in managing this issue. This technique is a viable option to correct diaphyseal malunion about the femur and tibia. Recently, the indications of a clamshell osteotomy have been expanded to function as a derotational or shortening osteotomy.

The clamshell incision (also known as a transverse or crossbow transsternal incision) was the common approach to the heart in the early days of cardiac surgery and was occasionally also used to access mediastinal tumors or both lungs. However, with the introduction of the median sternotomy, the clamshell incision was virtually forgotten, except for cardiothoracic trauma and double lung transplant. However, in rare situations, such as in large space-occupying lesions in the mediastinum, surgeons will resort to the clamshell approach to achieve exposure and complete resection. In this video tutorial, we demonstrate the operative steps for using the clamshell approach in one of those rare clinical scenarios. The resected mass was a giant mediastinal teratoma measuring 21 x 27 x 6 cm.

The dielectric properties and dielectric tunability of the nacreous part of the clamshell were investigated. Microstructure characterizations reveal that the sample shows a “brick-and-mortar” structure composed of aragonitic CaCO3 regions and bimacromolecule regions separated by transition regions consisting of crystalline particles surrounded by amorphous area. A ferroelectric-like dielectric tunability behavior was observed and an exciting dielectric tunability of 79% was achieved at 400 °C and 500 Hz within a small field increment of 34 V/cm. Such a low field scale for dielectric tunability near 80% rivals all known tunable dielectrics. Both thermally and electrically activated hopping motion of oxygen vacancies in the multilayered structures of the clamshell leads to the exciting low-field dielectric tunability. Our results dramatically expand the dielectric tunable materials and offer a facile way to achieve superior dielectric tunability in bio-multilayered materials.

Key Clinical Message Clamshell thoracotomy (CST) may be indicated and life‐saving in carefully selected cases of blunt trauma. As such, the current clinical stance of general contraindication of CST in blunt trauma should be reviewed and criteria developed to accommodate select cases, considering the diversity of injuries resulting from blunt trauma.

This paper reports on our investigation of the effects of surface roughness on the equilibrium shape and apparent contact angles of a droplet deposited on a fiber. In particular, the shape of a droplet on a roughened fiber is studied via the energy minimization method implemented in the surface evolver finite element code. Sinusoidal roughness varying in both the longitudinal and radial directions is considered in the simulations to study the effects of surface roughness on the most stable shape of a droplet on a fiber (corresponding a global minimum energy state). It is found that surface roughness delays droplet shape transition from a symmetric barrel to a clamshell or an asymmetric barrel profile. A phase diagram that includes the effects of fiber roughness on droplet configurations—symmetric barrel, clamshell, and asymmetric barrel—is presented for the first time. It is also found that droplet apparent contact angle tends to decrease on rough fibers. Likewise, roughness tends to increase the force required to detach a droplet from a fiber but the effect diminishes as droplet size increases relative to the size of surface roughness. The results presented in our study have been compared with experimental data or those from prior studies whenever possible, and good agreement has been observed.

We report the first direct measurements of clamping strains within individual wires of a 19 parallel wire strand constrained by a clamshell clamp. In these measurements neutron diffraction was used to determine the elastic strains along three orthogonal axes for all of the individual wires across the strand cross section underneath the clamp for various clamping loads. We observed that, while, for all clamping loads, the clamping strains within individual wires were heterogeneously distributed, increasing the clamping force significantly decreased the strain heterogeneity. In contrast, no strain heterogeneity was observed in a rigorous companion finite-element model of the strand unless dimensional variations in the wire diameters were introduced. Our results are in agreement with the hypothesis by Gjelsvik, which states that, within a parallel wire bridge cable, local variations in wire diameter due to manufacturing tolerances can lead to large variations in clamping constraint.

Optical refrigeration of a Yb:YLF crystal can be used to cool an arbitrary payload, utilizing a novel MgF2 thermal link in a completely vibration free optical cryocooler. We discuss the latest advances in the design and implementation of an astigmatic Herriott cell to optimize pump laser absorption in the cooling crystal, and are studying the adverse effects of absorption saturation. We investigate novel spectrally selective coatings of the clamshell to reduce the parasitic heat load on the crystal. By overcoming these challenges, we work towards cooling a silicon reference cavity to a temperature of 124 K.

We report the successful surgical repair of a cervical aortic arch and diverticulum with a brain circulation anomaly through a clamshell incision. Because of the reliability of selective antegrade cerebral perfusion and superior exposure, we chose an approach through a clamshell incision. We describe the utility of this approach for treating a cervical aortic arch with a diverticulum.

The clamshell thoracotomy is often used to access both hemithoraxes and the mediastinum simultaneously for cardiothoracic pathology, but this technique is rarely used for the excision of spinal tumors. We describe the use of a clamshell thoracotomy for en bloc excision of a 3-level upper thoracic chordoma in a 20-year-old patient. The lesion involved T2, T3, and T4, and it invaded both chest cavities and indented the mediastinum. After 2 biopsies to confirm the diagnosis, the patient underwent a posterior spinal fusion followed by bilateral clamshell thoracotomy for 3-level en bloc resection with simultaneous access to both chest cavities and the mediastinum. To demonstrate how the clamshell thoracotomy was used to facilitate the tumor resection, an operative video and illustrations are provided, which show in detail how the clamshell thoracotomy can be used to access both hemithoraxes and the mediastinum.

We report on the novel and successful use of local anaesthetic wound infusions via elastomeric pumps in a 17-year-old male who underwent emergent clamshell thoracotomy after sustaining a stab wound to the flank. This formed one component of a multi-modal analgesic regimen aimed at reducing opioid requirements and their associated side-effects. The patient was mobilising and was discharged from the intensive care unit 24 h postoperatively. There was an unplanned break in the local anaesthetic infusion during which the patient's reported pain scores increased significantly. The catheters were removed on the fifth postoperative day and he was discharged from hospital on day 7.

This chapter explains how to wrap and package optics for short- and long-term storage. It also explains how to wrap components for shipping to a vendor or customer. Once an optic is cleaned, the next steps are to wrap and/or store it, protect it from the elements, keep it free of contaminants, and prevent any possible damage. The methods presented have been developed over many years and have been used by the military, commercial, and optical industries. Wrapping methods use tissue, envelopes, and clamshell packaging, or a mixture of these materials.

In recent years, the heights of urban buildings have increased to make more efficient use of available urban space. Consequently, substructures supporting the building weight have become larger. Currently, the vertical transport of the excavated soil is conducted by a clamshell. However, the clamshell is a large construction machine, and its operation entails physical and time restrictions. This study focused on the intestinal tract that transports various fluids by contracting and relaxing the wall muscles. The aim was to downsize and automate the technology involved in the vertical transport of excavated soil with a peristaltic transport machine that simulates an intestine. The trend of transport performance was evaluated with artificial soil to understand the relation between the vertical-transport performance and driving condition of the multi-unit peristaltic transport machine. The changes in conveying performance were examined via an upload test using artificial soil. In addition, the weight of the lifted sand was measured by calculating the amount of sediment and water in the lifted sample.

Surgical management of lower extremity malunions and acute fractures in the setting of lower extremity deformities presents a unique challenge for orthopaedic surgeons. The objective of this study was to evaluate the outcomes of using the clamshell osteotomy in patients with acute fractures involving a malunion or deformity. A retrospective review of the cases performed by various orthopaedic traumatologists at 4 different trauma centers was performed to identify cases using the clamshell osteotomy from January 2012 to January 2016. Nine clamshell osteotomy cases were identified, 4 presenting fractures in the setting of previous malunions. All osteotomies healed within 15 months (average 6.8 ± 4.4 SD). In this multicenter case series, we demonstrate that using clamshell osteotomies can result in excellent outcomes for permitting intramedullary nailing of acute fractures in patients with lower extremity deformity.

In underground mining operation, air is contaminated with fine dusts that can be removed by filtration effectively. Filter cleaning is envisioned to prolong filter media lifetime and to ensure uninterrupted operation requiring little maintenance. For cake filtration, reverse airflow or pulse flow, or filter shaking are widely used. But for depth bed filtration which is needed to meet more stringent emission requirement, continuous filter cleaning is generally not practical. The concept of continuous liquid rinsing of depth filter media is proposed and preliminary studies are performed. These laboratory studies on single vertical fibers include hydrodynamic tests of water along various filter fibers as well as cleaning with different sample dusts. All tested fibers have hydrophobic properties that result in the formation of clamshell droplets with moderate particle removal success. Small, plate-like particles are particularly difficult to remove. Comparative tests with oil that forms a homogeneous film provide excellent particle removal.

Optical refrigeration of rare-earth-doped solids has reached the boiling point of argon, 87 K, and is expected to cool to that of nitrogen, 77 K, in the near future. This technology is poised to pave the way to compact, reliable, and vibrationfree all-solid-state optical cryocoolers. By attaching the Yb:YLF cooling crystal to a cold finger via a double 90° kink thermal link, we have cooled a silicon temperature sensor to below 151 K. An advanced design of the thermal link and the clamshell surrounding the cooled assembly successfully controlled the flow of heat and radiation to allow cooling of a payload to cryogenic temperatures. Key elements of the design were a low-absorption thermal link material, an optimized thermal link geometry, and a spectrally-selective coating of the clamshell.

We report methods to generate three-dimensional maps of birefringence, its position and orientation in juvenile shells of the Atlantic hard clamshell (Mercenaria mercenaria). For measuring the retardance and optic axis orientation of curved shell surfaces in three dimensions, we developed enhanced acquisition and processing algorithms and combined results from conventional and light field imaging approaches to reconstruct the three-dimensional shell shape and its anisotropic optical properties. Our work represents the first successful attempt to generate such maps at a spatial resolution of about 2 μm and angular steps of about 9° in terms of the inclination angles of the optic axis. The maps of clamshell birefringence provide structural insights into the early mineralization during juvenile clamshell development.

The durability of the metal structure of a clamshell crane is predicted in two ways: by the hypothesis of linear summation of damage and using the model of cyclic degradation of the static properties of the material. In the second case, a conservative estimate of longevity is obtained for a quasi-random stress spectrum at the dangerous point of the span beam. A significant influence of structural damping on the service life of the crane has been revealed. Calculations by the developed algorithm are performed on an ordinary personal computer with a small expenditure of computer time. © 2018 Author(s).

The design of injection die on the upper cover of clamshell phone is introduced. The dual-plate die has side gate for opposite glue injection, the parts are ejected by ejector pin, the side reversed buckle contains three blocks, the reversed buckle at flip shaft consists of two inner sliders, and all the eight inner reversed buckles are made up of inclined pushing rods, and the cooling system embraces "U" shaped cooling waterway. Its application in practice has proved the reasonable die structure, smooth remolding, and qualified plastic part design.

As a ship of high technology content, dredger is equipped with a very important structural part—spud. In actual working condition, spud is affected by seabed terrain and force of sediment. Moreover, water flow and wind will impact the hull. Consequently, the effect of moment of force on the hull’s center of gravity will cause heeling of the hull. This paper, with the help of geometrical relationship, is to quantificationally analyze and calculate the influence of transverse, longitudinal sloping and ordinary heeling on the underwater positioning accuracy of clamshell in the condition of heeling. Then it offers relevant compensation, in order to reduce the accuracy error of clamshell’s underwater positioning caused by hull’s heeling.

This paper proposes a problem of flat dredging because of the phenomenon of overdredging casuing bottom roughness in dredging engineering and presents the formulation of the inverse kinematics and dynamics simulation of a dredging clamshell. A dynamical model of dredging clamshell is built based on Adams and the position analysis is firstly performed by adding a general point motion to the dredging clamshell. By analyzing and solving kinematics equations in inverse, movement curves of the steel wire ropes are obtained, and the pulling force curves are acquired by dynamics simulation. The results show that the method automatically generates inverse dynamic solutions and the movement curves are intuitive and can offer help to the flat dredging control scheme effectively.

Clamshell (bilateral anterolateral thoracotomy combined to transverse sternotomy) is an invasive surgical approach that is helpful in particular situations, especially bilateral lung transplantation. The closure technique remains challenging because clamshell incision can end with override, separation, or sternal pseudarthrosis complications. We describe the use of new absorbable sternal pins to stabilize the sternal closure and to help avoid additional sternal complications.

Background Ewing Sarcoma (ES) and Neuroblastoma (NB) belong to a family of tumours of primitive neuroectodermal origin (PNET) that occurs in both bone and soft tissue. Notwithstanding ES and NB are two distinct malignant tumours, sometimes there could be a link between them. Case report We describe a case of an extraosseous ES localized in the retrosternal region and the upper lobe of the right lung, which had been previously treated for NB in a 6 years old female. We treated this case with a clamshell approach which allows, in a one-step surgery, a complete excision of the mass reconstructing the hemysternectomy with a non-crosslinked matrix. Conclusion the clamshell approach is therefore useful to achieve the retrosternal space and the lung with a single surgical access. According to our experience, we consider appropriate to use a non-crosslinked matrix for sternal reconstruction.

The clamshell fracture of the femoral head and its arthroscopic osteosynthesis are described. This suprafoveal osteochondral fracture may have folded onto itself during closed reduction of the associated anterior hip dislocation. The resultant fracture fragment had almost circumferential chondral coverage that required arthroscopic manipulation to "pry apart the clamshell," permitting arthroscopic reduction. This patient also had pre-existing silent femoroacetabular impingement, and the novel use of arthroscopic acetabuloplasty permitted internal fixation by improving the path for headless screw fixation. The arthroscopic techniques and clinical outcome at greater than 2 years are presented. Albeit rare, the clamshell fracture configuration should be recognized and may be amenable to successful arthroscopic osteosynthesis. Of broader clinical impact and application, adjunctive acetabuloplasty may permit the successful osteosynthesis of select femoral head fractures in patients with concurrent acetabular overcoverage by completely arthroscopic techniques that engage both the fracture fragment and the attractive benefits of less invasive surgery.

The most common excavation methods for the construction of tunnels in urban areas are the ‘cut and cover’ method and the traditional method of excavation at the tunnel face. The first method is usually used for works at shallow depths, even though it frequently involves burdensome deviations and shifting of the existing underground plants and networks. It has been used to realise the Underground Railway Link in Turin (Italy), where excavation was made using trench-cutters and clam excavators. The results of a technical–operational comparison between the two techniques are presented in this work, from which the advantages concerning the use of trench-cutters compared to the use of clamshell bucket excavators have been determined.

Surgery for lung cancer involving the carina is challenging as it requires special surgical techniques and airway management. We report how we successfully treated carinal invasion of primary lung cancer by performing left sleeve pneumonectomy through a clamshell incision, as bilateral thoracotomy through a transverse sternotomy. Without a cardiopulmonary assist device, adequate ventilation and oxygenation were maintained across the operative field with a spinal tube. Tracheobronchial anastomosis was relatively easy to perform, with an excellent surgical view. The patient had an uneventful postoperative course and was discharged from hospital without oxygen support. There was no evidence of complications at the anastomosis on chest computed tomography and no sign of recurrence during 6 months of follow-up. The clamshell incision approach provided an excellent surgical view without the need to change the position of the patient during the operation. Thus, it could prove a useful procedure for carinal surgery; especially left sleeve pneumonectomy., The original publication is available at www.springerlink.com, Surgery Today, 42(6), pp.593-596; 2012

Climate change skeptics have pointed to wind turbines as subsidy-dependent folly for decades. But that scenario is rapidly being blown away. Thanks in part to novel polymer chemistry, turbines are on track to leave the cost of electricity from fossil fuels in their shadows. Onshore wind turbines already compete with coal and gas in Europe, generating electricity at a cost between $59 and $125 per MWh, according to the European Commission. And turbines should get even more competitive as polymer chemists work to improve them by developing lighter and stronger materials that make for longer and more efficient blades. Most turbine blades are fabricated by combining epoxy resin with fiberglass in a giant mold. Typically, sheets of fiberglass are laid over a balsa wood frame to create top and bottom halves of the blade. The halves are sealed together like a clamshell and then impregnated with epoxy and its hardening

The presence of hand could alter the energy absorbed in the human head. Hence, a study of the interaction between mobile device antennas and human head in the presence of metallic hand worn jewellery on human hand with different holding ways is investigated. A finite-difference time domain (FDTD) method has been performed by considering an internal PIFA antenna as the radiating source mounted at the top of a commercial clamshell phone positioned nearer the ear. With the introduction of hand-worn jewellery in variation parameters, there were perceptible effects on SAR variation in the human head. SAR distribution in the SAM head was found decreases due to different hand positions. Therefore, the head and in particular the hand may further impairment radiation performance of a mobile device.

Problem statement: Permeable Reactive Barriers (PRBs) were one of the most widespread solutions for the remediation of contaminated aquif ers. Although, a variety of excavation methods had been developed, backhoe (hydraulic excavators) were commonly used for the construction of PRBs in North America. Approach: In Europe, the most common method of slurry excavation was with a hydraulic grab and crane. The aim of this study was to compare clamshell and backhoe excavation techniques and to describe the installation of a fu ll scale PRB using a crawler crane equipped with a hydraulic grab. Results: Backhoes had been used on a larger number of PRB installations and permit a rapid rate of excavation and generally require less skill to master. Long stick backhoes were capable of digging as deep as 30 m. Instead, clamshell excavat ors require more skill to use, but were able to excavate to a depth of more than 70 m, with a high degree of precision. Two similar case studies were presented to compare the relative merits of the two excavation techniques. Conclusion/Recommendations: The first describes a funnel and gate system excava ted by long stick backhoe, in the US, whose longest gate is 0.73 m th ick, 68 m long and up to 13 m deep. The latter is a 0.6 m thick, 120 m long and 13 m deep continuous PRB, excavated by crane mounted grab to remediate a chlorinated hydrocarbons plume, in Avigliana, near the city of Torino, in Italy. Comparison of the two techniques is performed on the availability of instrumentation, excavation power and precision, potential for cost savings.

Stable performances of an internal WWAN antenna applied in the clamshell mobile phone with various chassis shapes are obtained. Six different states including five possible operating states and one closed state (idle condition) of the clamshell mobile phone, wherein the chassis shapes (main ground and upper ground) vary greatly, are studied. The WWAN antenna is mounted at the bottom of the main ground, and there are three connecting positions between the main ground and the upper ground. For each operating states, the upper ground is connected to the main ground at one of the three connecting positions. At each position, a band-stop circuit formed by two parallel LC chip elements is embedded, which is designed to excite a parallel resonance at around 900 MHz and hence leads to very high impedance seen into the upper ground in the 900 MHz band. This greatly decreases the excited surface currents on the upper ground, making the presence of the upper ground to have very small effects on the performances of the WWAN antenna mounted at the bottom of the main ground. At around 1900 MHz, owing to its shorter wavelength, the surface currents on the upper ground excited by the WWAN antenna on the main ground are small. Thus, over both the 900- and 1900-MHz bands, the various orientations of the upper ground to the main ground cause small effects on the WWAN antenna embedded therein. Details of the obtained results are presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52: 2148–2154, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25413

An internal wireless wide area network (WWAN) antenna applied in a clamshell mobile phone having an equivalent band-stop circuit at the hinge to decrease the upper ground plane effects of the mobile phone on the antenna performances is presented. The internal WWAN antenna in this study is a small-size printed monopole mounted at the bottom of the main ground. This band-stop circuit can perform a parallel resonance at around 900 MHz and leads to high impedance seen into the upper ground in the 900 MHz band, which greatly decreases the excited surface currents on the upper ground. At around 1900 MHz, owing to its shorter wavelength, the surface currents on the upper ground excited by the internal antenna on the main ground are small for both the traditional and proposed clamshell mobile phone structures. Hence, over the WWAN operating bands, the presence of the upper ground shows very small effects on the impedance matching and radiation characteristics of the antenna on the main ground. The SAR and HAC studies on the proposed clamshell mobile phone structure are also presented. © 2010 Wiley Periodicals, Inc. Microwave Opt Technol Lett 52:922–930, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.25056

The complex structure of the package systems currently used by the strawberry industry has prevented an efficient design of the forced-air cooling process. In this study, we investigated the mechanisms through which different design parameters affect the rate and uniformity of cooling, using a previously validated computational fluid dynamics model. The results indicated that the vent area has a significant effect on the cooling rate, but not on its uniformity. A design that reduces bypassing will not necessarily increase the cooling rate, because there is less bypass air to cool down the air exiting from each clamshell, so that the air entering the next clamshell becomes warmer. Periodic airflow reversal improves the rate and homogeneity of the cooling process.

An internal clamshell mobile phone antenna using a simple dual-band folded monopole slot for covering penta bands of WWAN operation is presented. The folded monopole slot has a length of about 60 mm only and is easily printed on the top portion (10 times 40 mm2) of the main circuit board and suitable to be placed at the hinge of the clamshell mobile phone. By further placing the connecting strip between the two ground planes to be in the vicinity of the open end of the monopole slot, the two (main and upper) ground planes of the clamshell mobile phone can also be excited to be efficient radiators (dipole-like chassis or groundplane modes excited through the strong electric field occurred at the slot's open end). By incorporating the resonant modes contributed from both the monopole slot and the two ground planes, two wide bands at about 900 and 1900 MHz are formed, which easily cover GSM850/900/1800/1900/UMTS operation. Owing to the additional resonant modes contributed by the two ground planes, the use of a simple folded monopole slot is sufficient to cover penta-band WWAN operation. This leads to compact size for the proposed clamshell mobile phone antenna. Details of the proposed antenna, including its SAR results, are presented.

An internal wireless wide-area network (WWAN) antenna suitable for GSM850/900/1800/1900/UMTS operation in the clamshell mobile phone with reduced ground plane effects is presented. Small variations in the performances of the antenna for the clamshell mobile phone in the open state (talk condition) and closed state (idle condition) are obtained. This is owing to the reduced effects of the upper (cover) ground plane on the performances of the internal antenna obtained by embedding a slit at the edge of the upper ground plane close to the connecting strip between the two (upper and main) ground planes of the clamshell mobile phone. In this case, large surface currents excited around the slit are achieved, with other portions of the upper ground plane showing much weaker surface current distributions, which makes the embedded slit behaves like a current trap for the excited surface currents. This condition results in reduced effects of the upper ground plane. This also makes the near-field radiation of the clamshell mobile phone with the proposed antenna easily meet the specific absorption rate (SAR) and hearing aid compatibility (HAC) specifications required for practical applications.

In this study, a simple uniplanar printed PIFA occupying a small area of 10 × 40 mm2 for achieving multiband operation in the clamshell mobile phone is presented. The proposed PIFA is formed by a simple shorted radiating strip coupled-fed by a simple feeding strip and is mounted at the hinge of the clamshell mobile phone; further, the upper ground plane is connected to the main ground plane using an extended connecting strip. With the coupling feed and the connection arrangement between the main and upper ground planes, the proposed PIFA itself is not only an efficient radiator, it can also excite the two ground planes of the clamshell mobile phone as an efficient radiator (dipole-like resonant modes are excited). Thus, with a small occupying area and a simple structure for the proposed PIFA, two wide operating bands at lower and higher frequencies can be provided to cover GSM850/900/1800/1900/UMTS bands for WWAN operation. The antenna also meets the 1-g SAR specification of 1.6 W/kg required for practical applications. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2805–2810, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24756

A loop chip antenna with an FR4 chip base suitable for clamshell mobile phone application to achieve wireless wide area network operation and hearing-aid compatibility (HAC) is presented. The loop chip antenna is formed by a loop strip excited by a capacitively coupled feed, all printed on the surfaces of the FR4 chip base to achieve a small size of 1.35 cm3 only. Two resonant loop paths are provided by the antenna and each loop path can generate its 0.5λ and 1.0λ resonant modes with good impedance matching. The excited loop resonant modes are formed into two wide operating bands for the antenna to cover GSM850/900 and GSM1800/1900/UMTS operations for both the open (talk) and closed (idle) states of the clamshell mobile phone. Furthermore, the loop antenna also excites small surface currents on the two ground planes of the clamshell mobile phone. In this case, weak near-field EM fields in the vicinity of the mobile phone can be generated. Results show that the strengths of the near-field E-field and H-field fall in the M3 or M4 Category, making the clamshell mobile phone with the proposed antenna to be an HAC communication device. The obtained specific absorption rate values in 1-g and 10-g head tissues also meet the limit of 1.6 and 2.0 W/kg, respectively. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 2327–2335, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24665