Reduced power selective excitation radio frequency pulses

A pulse synthesis algorithm is described that allows for the synthesis of selective radio frequency pulses requiring less peak power. The pulses thus synthesized have the same duration, total energy, and frequency response as those synthesized by the standard algorithm. Their phase function is, however, different. The power reduction is typically on the order of 60–70%. This modification will increase the utility of optimized selective pulses.     

Transdermal Delivery of Human Growth Hormone Through RF-Microchannels

No HeadingPurpose. To evaluate the bioavailability and bioactivity of human growth hormone (hGH) delivered transdermally through microchannels (MCs) in the skin created by radio-frequency (RF) ablation.Methods. The creation of MCs was observed in magnified rat and guinea pig skin after staining by methylene blue. Various doses of hGH in a dry form were applied on rat or guinea pig (GP) skin after the formation of MCs. The pharmacokinetic profile of systemic hGH in both animal models was monitored for 15 h post patch application. Bioactivity of the transdermally delivered hGH was verified by measuring IGF-I levels in hypophysectomized rats.Results. The ordered array of MCs was clearly visible in the magnified rat and guinea pig skin. The MCs were very uniform in diameter and of equal separation. Creation of MCs in the outer layers of the skin enabled efficient delivery of hGH, with a bioavailability of 75% (rats) or 33% (GPs) relative to subcutaneous (s.c.) injection with plasma profiles resembling that of s.c. injection. Elevated levels of systemic insulin-like growth factor-1 (IGF-I) were observed after transdermal delivery of hGH to hypophysectomized rats indicative of the bioactivity of the transdermally delivered hGH in vivo.Conclusions. Formation of RF-microchannels is a well-controlled process. These MCs permitted the transdermal delivery of bioactive hGH in rats and GPs with high bioavailability.     

Trial of a quantitative method for evaluating hemangioma of the liver and hepatocellular carcinoma using a radio-frequency signal

Purpose In recent years, advances in ultrasonographic techniques have allowed the detection of even small hepatocellular carcinomas. However, many cases do not show distinctive ultrasonographic features. A quantitative ultrasonographic procedure for making the diagnosis would therefore be desirable. It is recognized that radio-frequency (RF) signals from hepatic tumors conform to the K distribution. The K distribution is used for the characterization of the statistical properties of backscattering signals from heterogeneous regions. In this study, RF signals were acquired from hemangioma of the liver (hemangioma) and hepatocellular carcinoma (HCC), and parameters of the K distribution, i.e., φ (the mean square of the amplitude of RF signals) and α (the number of effective scatterers), were calculated for the quantitative ultrasonographic evaluation of hepatic tumors. Methods This study included 10 nodules of 10 patients with hemangioma and 27 nodules of 24 patients with HCC. The A-mode RF signals passing through the hepatic tumors were acquired with an Aloka SSD-1000 ultrasound system, and measurement units comprising 279 points were set on the RF signals corresponding to the tumor lesion. The parameters of the K distribution that were most consistent with the histogram were calculated and assessed. Results With regard to φ, the values were high in hemangioma, and there was a significant (P < 0.05) difference in the φ value between hemangioma and HCC. On the other hand, there was no significant difference in the α value between hemangioma and HCC. Conclusion The α values of hemangioma were equivalent to those of HCC, while the φ values for hemangioma were higher than those for HCC. It was deduced from these observations that a situation in which an electron beam is likely to scatter exists in the tumor. This is also consistent with the pathological findings reported from previous studies. The use of these parameters is expected to allow quantitative ultrasonographic evaluation of hepatic tumors.     

鼻内窥镜联合低温射频等离子消融术微创治疗鼻中隔偏曲并鼻甲肥大疗效分析

目的探讨鼻内窥镜联合低温射频等离子消融术微创治疗鼻中隔偏曲并鼻甲肥大的手术治疗方法及其疗效。方法对36例鼻中隔偏曲并一侧或双侧下鼻甲和中鼻甲肥大的患者，应用鼻内镜下鼻中隔偏曲矫正手术，低温射频等离子对肥大鼻甲消融微创治疗。结果36例患者均能在局麻下完成治疗，随访3个月以上，该方法能彻底矫正鼻中隔偏曲，有效的缩小肥大鼻甲，术后患者鼻塞、头痛改善或消失，无并发症发生。结论鼻内窥镜联合低温射频等离子消融术微创治疗鼻中隔偏曲并鼻甲肥大效果明显，创伤小，安全，有较好的临床应用价值。     

Application of radio-frequency identification in perioperative care

Every perioperative department could benefit from having an information system that facilitates managerial function and improves efficiency in the OR. The Patient Advancement Monitoring System–Surgical implemented in a hospital in Taipei, Taiwan, is one such a system that uses radio-frequency identification technology for tracking perioperative care of patients along workflow checkpoints. This web-based medical information system can facilitate care provided throughout perioperative services by providing instant patient information to staff members in cross-functional health care teams. Manpower is not wasted on duplicating data entry because the surgical progression is displayed in real time. Satisfaction with the system has been high for both nurses and administrators.     

Successful treatment of verrucous epidermal nevus with fractional micro-plasma radio-frequency technology and photodynamic therapy

Verrucous epidermal nevus (VEN) is a skin disorder that commonly presents at birth; it is characterized by skin-colored to brown verrucous papules in a linear distribution following Blaschko’s lines. Even though it is extremely rare, VEN has been associated with malignant transformation. VEN has been treated by different treatment modalities with varying and frustrating results. We introduce a new type of treatment. The fractional micro-plasma radio-frequency (RF) technology, which uses unipolar RF technology to provoke plasma spars, creating multiple controlled micro-perforations on the skin. Photodynamic therapy (PDT) is a type of technology for disease diagnosis and treatment, in which a photosensitizer gathers within the nidus and kills the diseased cells. In this report, we present a case of VEN that was successfully treated with fractional micro-plasma RF technology and PDT without side effects or complications; a follow-up was conducted after 24 months and no signs of recurrence were observed.     

Endothelial cell growth on oxygen-containing films deposited by radio-frequency plasmas: the role of surface carbonyl groups

Polystyrene substrates were modified by radio-frequency plasma deposition from mixtures of various organic vapors (acetone, methane, methanol, and formic acid) and oxygen. The resulting surfaces exhibited a wide range of surface oxygen concentrations, as measured by electron spectroscopy for chemical analysis (ESCA). The surface hydroxyl, carboxyl, and carbonyl groups were derivatized with trifluoroacetic anhydride, trifluoroethanol, or hydrazine, respectively, and their concentrations subsequently determined by ESCA. The growth of bovine aortic endothelial cells was found to increase with the surface carbonyl concentration but did not appear to correlate with the hydroxyl or carboxyl concentrations.     

内镜下射频治疗消化道息肉500例临床疗效分析

目的观察射频治疗消化道息肉的效果。方法用射频治疗仪，内镜下对500例610颗不同大小，有蒂或无蒂，单发或多发息肉，予以射频电切治疗。结果全部病例均治愈，无穿孔及电凝电切术后综合症。结论射频电治疗消化道息肉效果肯定，不开刀、无痛苦、费用低、前景广阔。     

磁共振射频线圈单元数对图像信噪比的影响

在磁共振成像过程中,射频线圈用来接收信号,对成像的质量起着至关重要的作用。用户在采购磁共振设备时往往用线圈的通道数和单元数来评价一个线圈的成像能力,而线圈的通道数又必须和系统的接收通道数相匹配,因此一般认为,在系统其他条件一定的情况下,线圈的单元数越多,成像质量越好。本文以PhilipsAchieva3．0T磁共振为平台,分别选取78通道8单元的SenseHead（头部）线圈和16通道18单元的SenseNeurovascular（神经血管）线圈作为比较对象进行扫描,比较两者成像的信噪比。另外,选取15通道15单元SenseSpine（全脊柱）线圈,先后用不同数量的采集单元数成像,然后对信噪比进行评价。