Waveguide Manufacturing Technologies for Next-Generation Millimeter-Wave Antennas.

Some recent waveguide-based antennas are presented in this paper, designed for the next generation of communication systems operating at the millimeter-wave band. The presented prototypes have been conceived to be manufactured using different state-of-the-art techniques, involving subtractive and additive approaches. All the designs have used the latest developments in the field of manufacturing to guarantee the required accuracy for operation at millimeter-wave frequencies, where tolerances are extremely tight.

The techniques of uniportal video-assisted thoracoscopic surgery: lower lobectomies and lymphadenectomy.

Uniportal video-assisted thoracoscopic surgery (VATS) is probably the most successful single-incision approach worldwide, probably secondary to several specific circumstances: multiportal VATS was hardly getting his recognition in the thoracic surgeon's community; the extraordinary effort by his creators and believers for developing the technique and giving massive diffusion; the subjective feeling by surgeons who performed the approach about its benefits and advantages. Despite this, many efforts have focused on extending new indications and describing variations of the original intercostal uniportal VATS, but few quality papers have analyzed the real impact of the approach and its real advantages or disadvantages comparing to multiportal VATS. Thus, many surgeons still feel little confidence on the approach and reject his performance.

Tubeless major pulmonary resections.

From its inception, cutting edge minimally invasive thoracic surgery has pursued to barely produce patient perturbation. Although state of the art techniques such as uniportal approach have achieved a remarkable reduction in postoperative morbidity, there is still a way to go in patient comfort. A new 'tubeless' concept has surfaced as an alternative to double-lumen intubation with general anaesthesia combining non-intubated spontaneous breathing video-assisted thoracic surgery (VATS) surgery under loco-regional blockade with the avoidance of central line, epidural or urinary catheter and chest tube in selected patients.

Nonintubated uniportal VATS pulmonary anatomical resections.

Nonintubated procedures have widely developed during the last years, thus nowadays major anatomical resections are performed in spontaneously breathing patients in some centers. In an attempt for combining less invasive surgical approaches with less aggressive anesthesia, nonintubated uniportal video-assisted thoracic surgery (VATS) lobectomies and segmentectomies have been proved feasible and safe, but there are no comparative trials and the evidence is still poor. A program in nonintubated uniportal major surgery should be started in highly experienced units, overcoming first a learning period performing minor procedures and a training program for the management of potential crisis situations when operating on these patients.

On the estimation of the worst-case implant-induced RF-heating in multi-channel MRI.

The increasing use of multiple radiofrequency (RF) transmit channels in magnetic resonance imaging (MRI) systems makes it necessary to rigorously assess the risk of RF-induced heating. This risk is especially aggravated with inclusions of medical implants within the body. The worst-case RF-heating scenario is achieved when the local tissue deposition in the at-risk region (generally in the vicinity of the implant electrodes) reaches its maximum value while MRI exposure is compliant with predefined general specific absorption rate (SAR) limits or power requirements.

Pregnant women models analyzed for RF exposure and temperature increase in 3T RF shimmed birdcages.

Purpose: MRI is increasingly used to scan pregnant patients. We investigated the effect of 3 Tesla (T) two-port radiofrequency (RF) shimming in anatomical pregnant women models.

Theory And Methods: RF shimming improves B uniformity, but may at the same time significantly alter the induced current distribution and result in large changes in both the level and location of the absorbed RF energy.

Virtual population-based assessment of the impact of 3 Tesla radiofrequency shimming and thermoregulation on safety and B1 + uniformity.

Purpose: To assess the effect of radiofrequency (RF) shimming of a 3 Tesla (T) two-port body coil on B1 + uniformity, the local specific absorption rate (SAR), and the local temperature increase as a function of the thermoregulatory response.

Methods: RF shimming alters induced current distribution, which may result in large changes in the level and location of absorbed RF energy. We investigated this effect with six anatomical human models from the Virtual Population in 10 imaging landmarks and four RF coils.

Convex optimization of MRI exposure for mitigation of RF-heating from active medical implants.

Local RF-heating of elongated medical implants during magnetic resonance imaging (MRI) may pose a significant health risk to patients. The actual patient risk depends on various parameters including RF magnetic field strength and frequency, MR coil design, patient's anatomy, posture, and imaging position, implant location, RF coupling efficiency of the implant, and the bio-physiological responses associated with the induced local heating. We present three constrained convex optimization strategies that incorporate the implant's RF-heating characteristics, for the reduction of local heating of medical implants during MRI.

Non-intubated video-assisted thoracic surgery management of secondary spontaneous pneumothorax.

Secondary spontaneous pneumothorax (SSP) is serious entity, usually due to underlying disease, mainly chronic obstructive pulmonary disease (COPD). Its morbidity and mortality is high due to the pulmonary compromised status of these patients, and the recurrence rate is almost 50%, increasing mortality with each episode. For persistent or recurrent SSP, surgery under general anesthesia (GA) and mechanical ventilation (MV) with lung isolation is the gold standard, but ventilator-induced damages and dependency, and postoperative pulmonary complications are frequent.