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Sample records for bipolar radiofrequency device

  1. Skin tightening with a combined unipolar and bipolar radiofrequency device.

    Science.gov (United States)

    Mayoral, Flor A

    2007-02-01

    Monopolar radiofrequency (RF) devices are well established treatment modalities for tightening facial skin. A 60-year-old woman presented with a desire to tighten the lax skin and improve the appearance of both upper arms. A combination unipolar and bipolar RF device may provide volume reduction as well as skin tightening in the upper arm.

  2. Liver resection with bipolar radiofrequency device: Habib 4X.

    Science.gov (United States)

    Pai, Madhava; Jiao, Long R; Khorsandi, Shirin; Canelo, Ruben; Spalding, Duncan R C; Habib, Nagy A

    2008-01-01

    Intraoperative blood loss has been shown to be an important factor correlating with morbidity and mortality in liver surgery. In spite of the technological advances in hepatic parenchymal transection devices, bleeding remains the single most important complication of liver surgery. The role of radiofrequency (RF) in liver surgery has been expanded from tumour ablation to major hepatic resections in the last decade. Habib 4X, a new bipolar RF device designed specifically for liver resection is described here. Habib 4X is a bipolar, handheld, disposable RF device and consists of two pairs of opposing electrodes which is introduced perpendicularly into the liver, along the intended transection line. It produces controlled RF energy between the electrodes and the heat produced seals even major biliary and blood vessels and enables resection of the liver parenchyma with a scalpel without blood loss or biliary leak. Three hundred and eleven patients underwent 384 liver resections from January 2002 to October 2007 with this device. There were 109 major resections and none of the patients had vascular inflow occlusion (Pringle's manoeuvre). Mean intraoperative blood loss was 305 ml (range 0-4300) ml, with less than 5% (n=18) rate of transfusion. Habib 4X is an additional device for hepatobiliary surgeons to perform liver resections with minimal blood loss and low morbidity and mortality rates.

  3. [Clinical study of liver resection with bipolar radiofrequency device: Habib 4X].

    Science.gov (United States)

    Chen, Jian; Dong, Xin; Tang, Zhe; Gao, Shun-liang; Wu, Yu-lian; Fang, He-qing

    2013-08-27

    To assess the application value of a new radiofrequency device Habib 4X in liver resection. A retrospective study was performed during March 2010 to July 2011.Forty-four patients underwent liver resection with radiofrequency device Habib 4X and another 54 patients traditional liver resection.Intraoperative blood loss, blood transfusion, Pringle's maneuver requirement, liver parenchyma transaction time, liver function recovery, complications, mortality and recurrence were recorded. The mean resection time was (67 ± 22) min for Habib 4X group versus (93 ± 23) min for traditional group (P = 0.000). Pringle's maneuver was required in 10 patients (22.7%) for Habib 4X group and 31 (57.4%) for traditional group (P = 0.001). The mean blocking time was (7 ± 2) vs (18 ± 6) min (P = 0.001), mean blood loss volume (243 ± 132) vs (500 ± 421) ml (P = 0.002). Postoperative recovery of liver function was better in Habib 4X group than traditional group. None developed mortality in Habib 4X group. And no resection margin recurred during a 18-month follow-up. Bipolar radiofrequency device Habib 4X is recommended for pre-coagulation in hepatectomy. And the advantages of minimized blood loss and reduced resection time result in its lower rates of morbidity and mortality.

  4. The Feasibility of Hepatic Resections Using a Bipolar Radiofrequency Device (Habib®).

    Science.gov (United States)

    Civil, Osman; Kement, Metin; Okkabaz, Nuri; Haksal, Mustafa; Gezen, Cem; Oncel, Mustafa

    2015-08-01

    The bipolar radiofrequency device (Habib®) has been recently introduced in order to reduce intraoperative bleeding for a safe hepatic resection as an alternative to the conventional tools. However, indications, perioperative findings, and outcome of the device for hepatic resections remain and deserve to be analyzed. The current study aims to analyze the feasibility of the bipolar radiofrequency device (Habib®) for hepatic resections. Information of the patients that underwent hepatic resection using with the Habib® device between 2007 and 2011 was abstracted. Patient, disease, and operation-related findings and perioperative data were investigated. A total of 71 cases (38 [53.5 %] males, mean age was 56.8 ± 11.9) were analyzed. Metastatic disease (n = 55; 77.5 %) was the leading indication followed by primary liver and biliary malignancies (n = 7; 9.9 %), hemangioma (n = 5; 7 %), hydatid disease (n = 3; 2.8 %), and hepatic gunshot trauma (n = 1; 1.4 %). Metastasectomy was the most commonly performed procedure (n = 31; 56.3 %), but in 24 (77.4 %) cases, it was performed in addition to extended resections. Other procedures in the study patients include segmentectomy in 17, bisegmentectomy in 19, trisegmentectomy in 17, right or left hepatectomy in 8, and extended right/left hepatectomy in 3. The mean (±SD) operation time was 241.7 ± 78.2 min. The median amount of bleeding was 300 cc (range 25-2500), and 23 (32.4 %) cases required perioperative transfusion. The median hospitalization period was 5 days (range 1-47). Lengthened drainage (n = 9, 12.7 %) and intraabdominal abscess (n = 8, 11.23 %) were the most common problems. Hepatic resections using the Habib® device seem to be feasible in cases with primary and metastatic hepatic lesions and benign liver masses and even those with hepatic trauma. It may lessen the amount of intraoperative hemorrhage, although lengthened drainage and intraabdominal abscess

  5. Laparoscopic Habib 4X: a bipolar radiofrequency device for bloodless laparoscopic liver resection.

    Science.gov (United States)

    Pai, M; Navarra, G; Ayav, A; Sommerville, C; Khorsandi, S K; Damrah, O; Jiao, L R; Habib, N A

    2008-01-01

    In recent years the progress of laparoscopic procedures and the development of new and dedicated technologies have made laparoscopic hepatic surgery feasible and safe. In spite of this laparoscopic liver resection remains a surgical procedure of great challenge because of the risk of massive bleeding during liver transection and the complicated biliary and vascular anatomy in the liver. A new laparoscopic device is reported here to assist liver resection laparoscopically. The laparoscopic Habib 4X is a bipolar radiofrequency device consisting of a 2 x 2 array of needles arranged in a rectangle. It is introduced perpendicularly into the liver, along the intended transection line. It produces coagulative necrosis of the liver parenchyma sealing biliary radicals and blood vessels and enables bloodless transection of the liver parenchyma. Twenty-four Laparoscopic liver resections were performed with LH4X out of a total of 28 attempted resections over 12 months. Pringle manoeuvre was not used in any of the patients. None of the patients required intraoperative transfusion of red cells or blood products. Laparoscopic liver resection can be safely performed with laparoscopic Habib 4X with a significantly low risk of intraoperative bleeding or postoperative complications.

  6. Treatment of cellulite with a bipolar radiofrequency, infrared heat, and pulsatile suction device: a pilot study.

    Science.gov (United States)

    Wanitphakdeedecha, Rungsima; Manuskiatti, Woraphong

    2006-12-01

    Very few therapeutic options have proven effective in the treatment of cellulite. To evaluate the effectiveness and adverse effects of a bipolar radiofrequency (RF), infrared (IR) heat and pulsatile suction device for the treatment of cellulite. Twelve subjects were treated with the RF-light-based device. All subjects were treated twice weekly for a total number of eight to nine treatments. Subjects were evaluated using standardized photographs, and measurements of body weight and circumference of treatment sites at baseline, immediately after the last treatment, and four weeks and one year after the last treatment. Clinical improvement scores of comparable photographs using a quartile grading scale (0 = 75% improvement) were judged independently by two non-treating dermatologists after the series of treatment. The average body weights at baseline, immediately after the last treatment, and four weeks and one year after the complete treatment were 56.30, 56.05, 56.23, and 56.53 kg, respectively. The average circumferential reductions of the abdomen and thigh at the last treatment visit were 5.17 +/- 1.04 cm (6.32%+/- 1.82%) and 3.50 +/- 2.16 cm (6.23 +/- 3.58%), respectively. At four weeks after the last treatment, the average circumferential reductions of the abdomen and thigh were sustained at 3.17 +/- 2.75 cm (4.04%+/- 3.69%) and 3.50 +/- 2.04 cm (6.26%+/- 3.52%), respectively. At one year follow-up visit, the average circumferential reductions of the abdomen and thigh were maintained at 3.83 +/- 0.76 cm (4.64%+/- 1.15%) and 3.13 +/- 3.54 (5.50%+/- 6.12%), respectively. Average clinical improvement scores of the abdomen and thigh after the series of treatments were 0.75 (corresponding to approximately 25% improvement), and 1.75 (corresponding to approximately 50% improvement), respectively. A bipolar RF, IR heat and pulsatile suction device provides a beneficial effect on reduction of abdomen and thigh circumference, and smoothening of the cellulite.

  7. Thermometric determination of cartilage matrix temperatures during thermal chondroplasty: comparison of bipolar and monopolar radiofrequency devices.

    Science.gov (United States)

    Edwards, Ryland B; Lu, Yan; Rodriguez, Edwin; Markel, Mark D

    2002-04-01

    To compare cartilage matrix temperatures between monopolar radiofrequency energy (mRFE) and bipolar RFE (bRFE) at 3 depths under the articular surface during thermal chondroplasty. We hypothesized that cartilage temperatures would be higher at all cartilage depths for the bRFE device than for the mRFE device. Randomized trial using bovine cartilage. Sixty osteochondral sections from the femoropatellar joint of 15 adult cattle were used for this study. Using a custom jig, fluoroptic thermometry probes were placed at one of the following depths under the articular surface: 200 microm, 500 microm, or 2,000 microm. RF treatment was performed either with fluid flow (F) (120 mL/min) or without fluid flow (NF) (n = 5/depth/RFE device/flow; total specimens, 60). Irrigation fluid temperature was room temperature (22 degrees C). Thermometry data were acquired at 4 Hz for 5 seconds with the RF probe off, for 20 seconds with the RF probe on, and then for 15 seconds with the RF probe off. During RF treatment, a 0.79-cm2 area (1.0-cm diameter) of the articular surface centered over the thermometry probe was treated in a paintbrush manner in noncontact (bRFE) or light contact (mRFE). Thermal chondroplasty with bRFE resulted in higher cartilage matrix temperatures compared with mRFE for all depths and regardless of fluid flow. Bipolar RFE resulted in temperatures of 95 degrees C to 100 degrees C at 200 microm and 500 microm under the surface, with temperatures of 75 degrees C to 78 degrees C at 2,000 microm. Fluid flow during bRFE application had no effect at 200 microm. Monopolar RFE resulted in temperatures of 61 degrees C to 68 degrees C at 200 microm, 54 degrees C to 70 degrees C at 500 microm under the surface, and 28 degrees C to 30 degrees C at 2,000 microm below the surface. A significant effect of fluid flow during mRFE application occurred at 200 microm (NF, 61 degrees C; F, 63 degrees C) and 500 microm (NF, 53 degrees C; F, 68 degrees C). In this study, we found

  8. Assessment of efficacy and safety of a fractionated bipolar radiofrequency device for the treatment of lower face wrinkles and laxity.

    Science.gov (United States)

    Jiang, Yueqi; Zhang, Xuting; Lu, Zhong; Gold, Michael H

    2018-04-18

    Skin aging, as a natural course, is a gradual process. It can be classified as either intrinsic or photo-aging. In recent years, as the attention to lower face wrinkles and laxity has raised significantly, the demands to facial rejuvenation also increased, along with a variety of technologies coming into being. Fractional bipolar RF as a novel means of rejuvenation has been used in clinical practice, but questions remain in terms of its efficacy and safety. Considering a large population in our country and huge demands for skin tightening, we did this research to evaluate the efficacy and safety of fractional bipolar radiofrequency.

  9. “Edgeboost”: A Novel Technique to Extend the Ablation Zone Lateral to a Two-Probe Bipolar Radiofrequency Device

    International Nuclear Information System (INIS)

    Huo, Ya Ruth; Pillai, Krishna; Akhter, Javed; Morris, David L.

    2016-01-01

    BackgroundThe dual-electrode bipolar-RFA (B-RFA) is increasingly used to ablate large liver tumours (3–7 cm). However, the challenging aspect of B-RFA is the placement of the two electrodes around the tumour. Realignment often requires the electrodes to be extracted and reinserted.AimThe aim of this study is to examine “Edgeboost”, a novel technique to increase the lateral ablation dimension without requiring any realignment of the electrodes.Methods and MaterialsAn egg-white model and an ex vivo calf liver model were used compare the standard bipolar mode ablation to Edgeboost-1 (reaching full impedance in bipolar mode initially, then cycling in unipolar mode between left and right probes) and Edgeboost-2 (similar to Edgeboost-1 but not reaching full impedance initially in bipolar mode in order to minimize charring and, thus, to increase total ablation time).ResultsA significantly larger outer lateral ablation dimension to the probe was achieved with Edgeboost-1 compared to the standard method in the liver model (1.14 cm, SD: 0.16 vs. 0.44 cm, SD: 0.24, p = 0.04). Edgeboost-2 achieved the largest outer lateral ablation dimension of 1.75 cm (SD: 0.35). A similar association was seen in the egg model. Edgeboost-2 almost doubled the mass ablated with standard bipolar alone (mass ratio: 1:1.94 in egg white and 1:1.84 in liver).ConclusionThis study demonstrates that the novel “Edgeboost” technique can increase the outer lateral ablation dimension without requiring the two inserted electrodes to be reinserted. This would be beneficial for interventionists who use the dual B-RFA

  10. “Edgeboost”: A Novel Technique to Extend the Ablation Zone Lateral to a Two-Probe Bipolar Radiofrequency Device

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Ya Ruth, E-mail: ruth.huo@gmail.com; Pillai, Krishna, E-mail: panthera6444@yahoo.com.au; Akhter, Javed, E-mail: s8603151@unsw.edu.au; Morris, David L., E-mail: david.morris@unsw.edu.au [St George Hospital, Hepatobiliary and Surgical Oncology Unit, UNSW Department of Surgery (Australia)

    2016-01-15

    BackgroundThe dual-electrode bipolar-RFA (B-RFA) is increasingly used to ablate large liver tumours (3–7 cm). However, the challenging aspect of B-RFA is the placement of the two electrodes around the tumour. Realignment often requires the electrodes to be extracted and reinserted.AimThe aim of this study is to examine “Edgeboost”, a novel technique to increase the lateral ablation dimension without requiring any realignment of the electrodes.Methods and MaterialsAn egg-white model and an ex vivo calf liver model were used compare the standard bipolar mode ablation to Edgeboost-1 (reaching full impedance in bipolar mode initially, then cycling in unipolar mode between left and right probes) and Edgeboost-2 (similar to Edgeboost-1 but not reaching full impedance initially in bipolar mode in order to minimize charring and, thus, to increase total ablation time).ResultsA significantly larger outer lateral ablation dimension to the probe was achieved with Edgeboost-1 compared to the standard method in the liver model (1.14 cm, SD: 0.16 vs. 0.44 cm, SD: 0.24, p = 0.04). Edgeboost-2 achieved the largest outer lateral ablation dimension of 1.75 cm (SD: 0.35). A similar association was seen in the egg model. Edgeboost-2 almost doubled the mass ablated with standard bipolar alone (mass ratio: 1:1.94 in egg white and 1:1.84 in liver).ConclusionThis study demonstrates that the novel “Edgeboost” technique can increase the outer lateral ablation dimension without requiring the two inserted electrodes to be reinserted. This would be beneficial for interventionists who use the dual B-RFA.

  11. [Clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis].

    Science.gov (United States)

    Oyake, Daisuke; Ochi, Kentaro; Takatsu, Mitsuharu; Shintani, Toshiharu; Umehara, Tsuyoshi; Koizuka, Izumi

    2004-07-01

    The clinical effect of bipolar radiofrequency thermotherapy on allergic rhinitis was evaluated. A bipolar radiofrequency system (CelonLab ENT) was used to treat 16 patients suffering from allergic rhinitis between February 2003 and August 2003. The thermotherapy was performed under local anesthesia at the otolaryngology outpatient clinic of St. Marianna University Toyoko Hospital. Data were collected by questionnaire and rhinomanometry preoperatively and 2 months postoperatively. The mean visual analogue scale (VAS) score for intraoperative pain was 31 mm (range, 0-100), and nearly all the patients felt no or a subtle pain during the thermotherapy. Postoperative pain was also well tolerated, with nearly all the patients not requiring analgesic drugs. Postoperative bleeding was minor, and none of the patients required additional treatment for bleeding. Nearly all the patients reported an improvement in their nasal patency, rhinorrhea, headaches, and sleeping. Statistically significant improvements were observed for all the measured VAS scores: nasal patency, rhinorrhea, headache, and olfactory function. Nasal resistance, as measured by anterior rhinomanometry, significantly improved after treatment. The effect of decongestion was also measured using anterior rhinomanometry. The ratio of nasal resistance before and after decongestion was significantly higher after thermotherapy, suggesting that nasal decongestion had a smaller effect on nasal patency after treatment. The current results suggest that the CelonLab ENT device is an effective and safe treatment for allergic rhinitis.

  12. The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation.

    Science.gov (United States)

    Choi, Yeon Jin; Lee, Jung Yeon; Ahn, Ji Young; Kim, Myeung Nam; Park, Mi Youn

    2012-01-01

    As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. To compare Polaris WRA(TM), a combination device of diode light and RF, and ReFirme ST(TM), a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm2, RF fluence 90 J/cm3) on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm3) on the left half of their faces. Clinical photos of front and bilateral sides of the subjects' faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators' and the subjects' global assessments were performed. There is no statistically significant difference in the overall outcome between Polaris WRA(TM) and Refirme ST(TM) based on pre- and post-treatment objective measurements. Polaris WRA(TM) was more effective than Refirme ST(TM) at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA(TM)-treated facial area than that of Refirme ST(TM). Treatment was generally well tolerated, and there was no serious complication. In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at reducing wrinkles and pores when the therapeutic results of both the

  13. The safety and efficacy of a combined diode laser and bipolar radiofrequency compared with combined infrared light and bipolar radiofrequency for skin rejuvenation

    Directory of Open Access Journals (Sweden)

    Yeon Jin Choi

    2012-01-01

    Full Text Available Background: As the demand for noninvasive procedures for skin rejuvenation is increasing, combined diode laser and radiofrequency and combined infrared and radiofrequency devices have recently emerged. Aim: To compare Polaris WRA TM , a combination device of diode light and RF, and ReFirme ST TM , a combination device of infrared and bipolar RF, in terms of safety and efficacy on skin rejuvenation. Methods: Fourteen Korean volunteers of skin type II-IV, with facial laxity and periorbital rhytids, received three treatments at 3-week intervals with combined diode laser and bipolar radiofrequency (laser fluence 30 J/cm 2 , RF fluence 90 J/cm 3 on the right half of their faces and combined infrared light and bipolar radiofrequency (RF fluence 120 J/cm 3 on the left half of their faces. Clinical photos of front and bilateral sides of the subjects′ faces were taken at baseline and at 6, 9, 12 weeks after the treatment initiation. The investigators′ and the subjects′ global assessments were performed. Results: There is no statistically significant difference in the overall outcome between Polaris WRA TM and Refirme ST TM based on pre- and post-treatment objective measurements. Polaris WRA TM was more effective than Refirme ST TM at reducing wrinkles when therapeutic results of the two appliances were compared based on the patient satisfaction measurements. After the treatment with both instruments, histological increase in the production and rearrangement of collagen fibers at the dermal layer was observed. The density of the collagen fibers was more increased with the Polaris WRA TM -treated facial area than that of Refirme ST TM . Treatment was generally well tolerated, and there was no serious complication. Conclusion: In this study, both the lasers appeared to be safe, and effective methods for treating skin laxity and facial wrinkles. Combined diode laser and radiofrequency was more effective than combined infrared and radiofrequency at

  14. Kinetics and tissue repair process following fractional bipolar radiofrequency treatment.

    Science.gov (United States)

    Kokolakis, G; von Eichel, L; Ulrich, M; Lademann, J; Zuberbier, T; Hofmann, M A

    2018-05-15

    Fractionated radiofrequency (RF) tissue tightening is an alternative method to fractionated laser treatment of skin wrinkling, laxity and acne scars, with reduced risk of scarring or persistent pigmentation. The aim of this study was to evaluate and quantify the wound healing process after RF treatment. 12 patients were treated with a 64-pin fractional bipolar RF device with 60 mJ/pin applied energy. Confocal laser scanning microscopy (CLSM) examination was performed on day 1, day 2, day 7 and day 14 after treatment. Clinical wound healing process was measured and expressed as a percentage. All patients developed erythema, mild edema and crusts at the treated areas. Two weeks after treatment clinical symptoms resolved. During ablation patients reported moderate pain. Directly after ablation microscopic ablation zones could be detected in CLSM. Measurement of MAZ at epidermis, dermo-epidermal junction and papilary dermis showed a constant diameter until two weeks after treatment. Re-epithelization of the MAZ could be detected already 1 week after treatment. However, 2 weeks after ablation the honeycomb pattern of the epidermis was not yet completely restored. Bipolar fractionated RF treatment demonstrates clinically a rapid wound healing response. The subepidermal remodelling process still ongoing after 14 days, showing new granulation tissue. Therefore, treatment intervals of at least 14 days should be recommended to allow completion of the remodelling process.

  15. 47 CFR 2.801 - Radiofrequency device defined.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency device defined. 2.801 Section 2... MATTERS; GENERAL RULES AND REGULATIONS Marketing of Radio-frequency Devices § 2.801 Radiofrequency device defined. As used in this part, a radiofrequency device is any device which in its operation is capable of...

  16. Impact of cavitron ultrasonic surgical aspirator (CUSA) and bipolar radiofrequency device (Habib-4X) based hepatectomy for hepatocellular carcinoma on tumour recurrence and disease-free survival.

    Science.gov (United States)

    Huang, Kai-Wen; Lee, Po-Huang; Kusano, Tomokazu; Reccia, Isabella; Jayant, Kumar; Habib, Nagy

    2017-11-07

    The aim of this study was to evaluate the oncological outcomes of hepatocellular carcinoma patients undergoing liver resection using cavitron ultrasonic surgical aspirator (CUSA) or radiofrequency (RF) based device Habib-4X.
. We prospectively analyzed the data of 280 patients who underwent liver resection for hepatocellular carcinoma at our institution from 2010-2012 with follow up till August 2016. The CUSA was used in the 163 patients whilst Habib-4X in 117 patients. The end points of analysis were oncological outcomes as disease recurrence, disease-free survival (DFS) and overall survival (OS) were estimated by the Kaplan-Meier method, which has been compared with all other existing literature on the survival study. Compared with CUSA the reported incidence of recurrence was significantly lower, in Habib-4X group; p Habib-4X group than CUSA group (50.80 vs 45.87 months, p = 0.03). The median OS was better in Habib-4X group than CUSA group (60.57 vs 57.17 months, p = 0.12) though the lesser difference in OS between the groups might be explained by the use of palliative therapies as TACE, percutaneous RFA, etc. in case of recurrence. RF based device Habib-4X, is safe and effective device for resection of hepatocellular carcinoma, in comparison to CUSA with better oncological outcomes, i.e., significantly lesser tumour recurrence and better DFS. This could be explained on the basis of systemic and local immunomodulatory effect involving induction of kupffer cells and effector CD-8 T cells that help in minimizing postoperative complications and bring more advantageous oncological outcomes.

  17. A new technique for hepatic parenchymal transection using an articulating bipolar 5 cm radiofrequency device: results from the first 100 procedures.

    Science.gov (United States)

    Takahashi, Hideo; Akyuz, Muhammet; Aksoy, Erol; Aucejo, Federico; Quintini, Cristiano; Miller, Charles; Fung, John; Berber, Eren

    2018-04-13

    Parenchymal transection(PT) still remains a challenge in liver resection. The outcomes of the first experience of a novel vessel-sealer for hepatic transection were assessed. A bipolar articulating vessel-sealer (Caiman ® , Aesculap Inc., Center Valley, PA) was used in 100 liver resections through both open (OLR) and laparoscopic (LLR) approaches. All data were prospectively collected into an IRB-approved department database, and clinical, surgical and perioperative parameters were analyzed. Fifty patients underwent OLR and 50 patients underwent LLR. Eighty hepatectomies were performed for malignancy. Median number of tumors was 1, with the largest focus measuring an average of 5.1 cm. Forty-nine of the procedures were major liver resections. Parenchymal transection time was 29.9 ± 3.1 min in OLR and 29.9 ± 3.6 min in LLR. Median estimated blood loss was 300 cc (Inter-quartile range (IQR) 100-575 cc). Median hospital stay was 6 days for open and 3 days for laparoscopic procedures. Ninety-day complication rate was 8% without any mortality. Bile leak rate was 4%. Staplers were used for parenchymal transection in 16 cases. This study introduces a new multifunctional device into the armamentarium of the liver surgeon. In our experience, this device facilitated the parenchymal transection by adding speed and consolidating the amount of instrumentation used in liver resection without increasing complications. Copyright © 2018 International Hepato-Pancreato-Biliary Association Inc. Published by Elsevier Ltd. All rights reserved.

  18. Six years of evidence-based adult dissection tonsillectomy with ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection.

    Science.gov (United States)

    Ragab, S M

    2012-10-01

    To conduct an adequately powered, prospective, randomised, controlled trial comparing adult dissection tonsillectomy using either ultrasonic scalpel, bipolar electrocautery, bipolar radiofrequency or 'cold steel' dissection. Three hundred patients were randomised into four tonsillectomy technique groups. The operative time, intra-operative bleeding, post-operative pain, tonsillar fossa healing, return to full diet, return to work and post-operative complications were recorded. The bipolar radiofrequency group had a shorter mean operative time. The mean intra-operative blood loss during bipolar radiofrequency tonsillectomy was significantly less compared with cold dissection and ultrasonic scalpel tonsillectomy. Pain scores were significantly higher after bipolar electrocautery tonsillectomy. Patients undergoing bipolar electrocautery tonsillectomy required significantly more days to return to full diet and work. The bipolar electrocautery group showed significantly reduced tonsillar fossa healing during the first and second post-operative weeks. In this adult series, bipolar radiofrequency tonsillectomy was superior to ultrasonic, bipolar electrocautery and cold dissection tonsillectomies. This method combines the advantages of 'hot' and 'cold' tonsillectomy.

  19. Fractionated bipolar radiofrequency and bipolar radiofrequency potentiated by infrared light for treating striae: A prospective randomized, comparative trial with objective evaluation.

    Science.gov (United States)

    Harmelin, Yona; Boineau, Dominique; Cardot-Leccia, Nathalie; Fontas, Eric; Bahadoran, Philippe; Becker, Anne-Lise; Montaudié, Henri; Castela, Emeline; Perrin, Christophe; Lacour, Jean-Philippe; Passeron, Thierry

    2016-03-01

    Very few treatments for striae are based on prospective randomized trials. The objective of this study was to assess the efficacy of bipolar fractional radiofrequency and bipolar radiofrequency potentiated with infrared light, alone or combined, for treating abdominal stretch marks. Bicentric prospective interventional randomized controlled trial in the department of Dermatology of University Hospital of Nice and Aesthetics Laser Center of Bordeaux, France. Men and women of age 18 years or above, who presented for the treatment of mature or immature abdominal striae were included. The patients' abdomens were divided into four equal quadrants. Bipolar radiofrequency potentiated with infrared light and fractional bipolar radiofrequency were applied, alone or combined, and compared to the remaining untreated quadrant. The main criterion of evaluation was the measurement of depth of striae, using 3D photography at 6 months follow-up. A global assessment was also rated by the physician performing the treatment and by the patients. Histological analysis and confocal laser microscopy were additionally performed. A total of 22 patients were enrolled, and 384 striae were measured. In per protocol analysis mean striae depth was decreased by 21.64%, observed at 6 months follow-up with the combined approach, compared to an increase of 1.73% in the control group (P radiofrequency, combined with bipolar radiofrequency potentiated by infrared light, is an effective treatment of both immature and mature striae of the abdomen. © 2016 Wiley Periodicals, Inc.

  20. Use of bipolar radiofrequency in parenchymal transection of the liver, pancreas and kidney.

    Science.gov (United States)

    Pai, Madhava; Spalding, Duncan; Jiao, Long; Habib, Nagy

    2012-01-01

    Intraoperative blood loss has been shown to be an important factor correlating with increased morbidity and mortality in oncological surgery. Despite technological advances in parenchymal transection devices, bleeding remains the single most important complication. To address this, we designed and developed a bipolar radiofrequency (RF) device, the Habib 4X (Angiodynamics, Inc., Queensbury, N.Y., USA), which was initially used specifically for liver resections. A search using Medline, Embase and Google™ Scholar was performed for the period January 2001 to August 2011. The following Mesh terms were used: 'bipolar radiofrequency', 'Habib 4X', 'laparoscopic', 'liver resection', 'partial nephrectomy' and 'distal pancreatectomy'. The references of the studies included were also reviewed. Series from our centre were excluded. There were seven series published, reporting a total of 188 liver resections [113 minor (Habib 4X) device over this period. The median blood loss reported ranged from 15 to 427 ml with a transfusion rate of 0-14% In addition, five series of partial nephrectomies were also identified, reporting a total of 149 (45 open and 104 laparoscopic) cases. Hilar clamping was not used in any of the cases, and the mean blood loss reported was 100-337 ml whilst the transfusion rate ranged from 0 to 7.1%. There was only one published series of distal pancreatectomies; these were laparoscopic and included 14 patients. This review of bipolar RF-assisted liver resections, partial nephrectomies and distal pancreatectomies reported in the literature to date shows that there are significant advantages in using this device in these types of operation. Copyright © 2012 S. Karger AG, Basel.

  1. Fraxelated radiofrequency device for acne scars

    Science.gov (United States)

    Rao, Babar K.; Khokher, Sairah

    2012-09-01

    Acne scars can be improved with various treatments such as topical creams, chemical peels, dermal fillers, microdermabrasion, laser, and radiofrequency devices. Some of these treatments especially lasers and deep chemical peels can have significant side effects such as post inflammatory hyperpigmentation in darker skin types. Fraxelated RF Laser devices have been reported to have lower incidence of side effects in all skin phototypes. Nine patients between ages 18 and 35 of various skin phototypes were selected from a private practice and treated with a RF fraxelated device (E-matrix) for acne scars. Outcomes were measured by physician observation, subjective feedback received by patients, and comparison of before and after photographs. In this small group of patients with various skin phototypes, fraxelated radiofrequency device improved acne scars with minimal side effects and downtime.

  2. Bipolar Electrode Sample Preparation Devices

    Science.gov (United States)

    Wang, Yi (Inventor); Song, Hongjun (Inventor); Pant, Kapil (Inventor)

    2017-01-01

    An analyte selection device can include: a body defining a fluid channel having a channel inlet and channel outlet; a bipolar electrode (BPE) between the inlet and outlet; one of an anode or cathode electrically coupled with the BPE on a channel inlet side of the BPE and the other of the anode or cathode electrically coupled with the BPE on a channel outlet side of the BPE; and an electronic system operably coupled with the anode and cathode so as to polarize the BPE. The fluid channel can have any shape or dimension. The channel inlet and channel outlet can be longitudinal or lateral with respect to the longitudinal axis of the channel. The BPE can be any metallic member, such as a flat plate on a wall or mesh as a barrier BPE. The anode and cathode can be located at a position that polarizes the BPE.

  3. Heat Sink Effect on Tumor Ablation Characteristics as Observed in Monopolar Radiofrequency, Bipolar Radiofrequency, and Microwave, Using Ex Vivo Calf Liver Model

    Science.gov (United States)

    Pillai, Krishna; Akhter, Javid; Chua, Terence C.; Shehata, Mena; Alzahrani, Nayef; Al-Alem, Issan; Morris, David L.

    2015-01-01

    Abstract Thermal ablation of liver tumors near large blood vessels is affected by the cooling effect of blood flow, leading to incomplete ablation. Hence, we conducted a comparative investigation of heat sink effect in monopolar (MP) and bipolar (BP) radiofrequency ablation (RFA), and microwave (MW) ablation devices. With a perfused calf liver, the ablative performances (volume, mass, density, dimensions), with and without heat sink, were measured. Heat sink was present when the ablative tip of the probes were 8.0 mm close to a major hepatic vein and absent when >30 mm away. Temperatures (T1 and T2) on either side of the hepatic vein near the tip of the probes, heating probe temperature (T3), outlet perfusate temperature (T4), and ablation time were monitored. With or without heat sink, BP radiofrequency ablated a larger volume and mass, compared with MP RFA or MW ablation, with latter device producing the highest density of tissue ablated. MW ablation produced an ellipsoidal shape while radiofrequency devices produced spheres. Percentage heat sink effect in Bipolar radiofrequency : Mono-polar radiofrequency : Microwave was (Volume) 33:41:22; (mass) 23:56:34; (density) 9.0:26:18; and (relative elipscity) 5.8:12.9:1.3, indicating that BP and MW devices were less affected. Percentage heat sink effect on time (minutes) to reach maximum temperature (W) = 13.28:9.2:29.8; time at maximum temperature (X) is 87:66:16.66; temperature difference (Y) between the thermal probes (T3) and the temperature (T1 + T2)/2 on either side of the hepatic vessel was 100:87:20; and temperature difference between the (T1 + T2)/2 and temperature of outlet circulating solution (T4), Z was 20.33:30.23:37.5. MW and BP radiofrequencies were less affected by heat sink while MP RFA was the most affected. With a single ablation, BP radiofrequency ablated a larger volume and mass regardless of heat sink. PMID:25738477

  4. Combined infrared light and bipolar radiofrequency for skin tightening in Asians.

    Science.gov (United States)

    Yu, Carol S; Yeung, Chi K; Shek, Samantha Y; Tse, Raymond K; Kono, Taro; Chan, Henry H

    2007-07-01

    As the demand for non-invasive procedures for skin tightening is increasing, combined optical and radiofrequency (RF) devices have recently emerged. The purpose of this study is to evaluate the safety and efficacy of a device that combined broadband infrared (IR) light (700-2000 nm) and bipolar RF (electro-optical synergy [ELOS]) for non-ablative treatment of facial laxity. DESIGN/MATERIALS AND METHODS: Nineteen Chinese volunteers of skin types III-V, with facial laxity and periorbital rhytides, received three treatments at 3-week intervals with combined IR (700-2000 nm, 10 W/cm(2)) and RF energies (70-120 J/cm(3)). Standardized photographs were taken by the Canfield Visia CR system at baseline and serially for 3 months after the last treatment. Two masked assessors evaluated the photographs to assess the improvement in skin laxity. Patient satisfaction scores were also obtained. At 3 months after the last treatment, 89.5% of the subjects reported moderate to significant subjective improvement in skin laxity of cheek, jowl, periorbital area and upper neck, with a high overall satisfaction rating. Masked observers' assessments were less remarkable. Mild improvement in skin laxity was observed over mid and lower face. There was no serious complication. The combination of broadband infrared light and bipolar radiofrequency produces mild improvement of facial laxity in Asians with no serious adverse sequelae. A high patients' satisfaction is achieved. However, further studies are necessary to demonstrate the long-term effects of the procedure and to optimize treatment parameters. (c) 2007 Wiley-Liss, Inc.

  5. Bipolar radiofrequency in the treatment of dermatologic imperfections: clinicopathological and immunohistochemical aspects.

    Science.gov (United States)

    Montesi, Gianni; Calvieri, Stefano; Balzani, Alberto; Gold, Michael H

    2007-09-01

    Rapid progress in the technology for skin rejuvenation has allowed for shorter post-treatment times than ever before. An example of such technology is the radiofrequency (RF) device, which offers nonablative skin rejuvenation, particularly for skin tightening and wrinkle reduction. Medical devices that emit RF energy produce a change in the electrical charges of the treated skin creating an electron movement, and the resistance of the tissue to the electron movement generates heat. This article examines the mechanism of action of a new bipolar RF device, which emits RF energy through a handpiece with a bipolar electrode configuration, and assesses the clinical histological and immunohistochemical results on a sample group of patients who underwent a cycle of sessions with this device. Thirty patients affected with periocular wrinkles, glabellar wrinkles, slackness of the cheeks with accentuation of the nasogenian furrow, striae distensae at the scapulohumeral joint, abdomen, and gluteal-trochanteric areas, or acne scars were included. These patients underwent a cycle of 6 to 8 sessions with 2-week intervals with the new bipolar RF device undergoing photographic monitoring before treatment and at the end of the cycle of sessions. In addition, 15 patients from the sample group were subjected to 2 biopsies, one at the start of treatment and the other 3 months after the last treatment. All the patients showed improvement in treated imperfections from the second session onward, and they expressed their satisfaction at the end of the treatment cycle. The most notable clinical, histological, and immunohistochemical results were observed in the patients with abdominal striae distensae. In most cases, the temporary side effects observed consisted of rashes and ecchymosis. Two patients reported the formation of blisters on the treated area caused by excessively high RF settings. The new bipolar RF device proved to be effective, noninvasive, and easy to use. The improvement

  6. Radiofrequency Coblation Versus Intramural Bipolar Cautery for the Treatment of Inferior Turbinate Hypertrophy.

    Science.gov (United States)

    Shah, Anil N; Brewster, Douglas; Mitzen, Kelly; Mullin, David

    2015-09-01

    Compare intramural bipolar electrocautery and radiofrequency coblation in the treatment of inferior turbinate hypertrophy with regards to objective and subjective improvement in nasal obstruction, rate and type of complications, experience during the procedure, and rate of recovery. Prospective, single-blinded study. Single tertiary medical center from 2008 to 2010. Forty-one adult patients with inferior turbinate hypertrophy refractory to medical management were treated with radiofrequency coblation in one nostril and intramural bipolar cautery in the other. Subjective and objective data, including use of a Visual Analog Scale (VAS) for subjective outcomes, acoustic rhinometry, and nasal endoscopy, were then obtained from each patient comparing the 2 techniques. Radiofrequency coblation was significantly less painful than intramural bipolar cautery during the procedure (P = .03) and during the early postoperative period (P measured by acoustic rhinometry and subjective VAS outcomes. Radiofrequency coblation seems to offer an equivalent alternative to bipolar electrocautery for the treatment of inferior turbinate hypertrophy with less discomfort during the procedure and early post-operative period. © The Author(s) 2015.

  7. Use of bipolar radiofrequency catheter ablation in treatment of cardiac arrhythmias.

    Science.gov (United States)

    Soucek, Filip; Starek, Zdenek

    2018-05-23

    Background Arrhythmia management is a complex process involving both pharmacological and non-pharmacological approaches. Radiofrequency ablation is the pillar of non-pharmacological arrhythmia treatment. Unipolar ablation is considered to be the gold standard in the treatment of the majority of arrhythmias; however, its efficacy is limited to specific cases. In particular, the creation of deep or transmural lesions to eliminate intramurally originating arrhythmias remains inadequate. Bipolar ablation is proposed as an alternative to overcome unipolar ablation boundaries. Results Despite promising results gained from in vitro and animal studies showing that bipolar ablation is superior in creating transmural lesions, the use of bipolar ablation in daily clinical practice is limited. Several studies have been published showing that bipolar ablation is effective in the treatment of clinical arrhythmias after failed unipolar ablation, however there is inconsistency regarding safety of bipolar ablation within the available research papers. According to research evidence the most common indications for bipolar ablation use are ventricular originating rhythmic disorders in patients with structural heart disease resistant to standard radiofrequency ablation. Conclusions To allow wider clinical application the efficiency and safety of bipolar ablation need to be verified in future studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  8. Bipolar Radiofrequency Facet Ablation of the Lumbar Facet Capsule: An Adjunct to Conventional Radiofrequency Ablation for Pain Management.

    Science.gov (United States)

    Jacobson, Robert E; Palea, Ovidiu; Granville, Michelle

    2017-09-01

    Radiofrequency facet ablation (RFA) has been performed using the same technique for over 50 years. Except for variations in electrode size, tip shape, and change in radiofrequency (RF) stimulation parameters, using standard, pulsed, and cooled RF wavelengths, the target points have remained absolutely unchanged from the original work describing RFA for lumbar pain control. Degenerative changes in the facet joint and capsule are the primary location for the majority of lumbar segmental pathology and pain. Multiple studies show that the degenerated facet joint is richly innervated as a result of the inflammatory overgrowth of the synovium. The primary provocative clinical test to justify an RFA is to perform an injection with local anesthetic into the facet joint and the posterior capsule and confirm pain relief. However, after a positive response, the radiofrequency lesion is made not to the facet joint but to the more proximal fine nerve branches that innervate the joint. The accepted target points for the recurrent sensory branch ignore the characteristic rich innervation of the pathologic lumbar facet capsule and assume that lesioning of these recurrent branches is sufficient to denervate the painful pathologic facet joint. This report describes the additional targets and technical steps for further coagulation points along the posterior capsule of the lumbar facet joint and the physiologic studies of the advantage of the bipolar radiofrequency current in this location. Bipolar RF to the facet capsule is a simple, extra step that easily creates a large thermo-coagulated lesion in this capsule region of the pathologic facet joint. Early studies demonstrate bipolar RF to the facet capsule can provide long-term pain relief when used alone for specific localized facet joint pain, to coagulate lumbar facet cysts to prevent recurrence, and to get more extensive pain control by combining it with traditional lumbar RFA, especially when RFA is repeated.

  9. Oxide bipolar electronics: materials, devices and circuits

    International Nuclear Information System (INIS)

    Grundmann, Marius; Klüpfel, Fabian; Karsthof, Robert; Schlupp, Peter; Schein, Friedrich-Leonhard; Splith, Daniel; Yang, Chang; Bitter, Sofie; Von Wenckstern, Holger

    2016-01-01

    We present the history of, and the latest progress in, the field of bipolar oxide thin film devices. As such we consider primarily pn-junctions in which at least one of the materials is a metal oxide semiconductor. A wide range of n-type and p-type oxides has been explored for the formation of such bipolar diodes. Since most oxide semiconductors are unipolar, challenges and opportunities exist with regard to the formation of heterojunction diodes and band lineups. Recently, various approaches have led to devices with high rectification, namely p-type ZnCo 2 O 4 and NiO on n-type ZnO and amorphous zinc-tin-oxide. Subsequent bipolar devices and applications such as photodetectors, solar cells, junction field-effect transistors and integrated circuits like inverters and ring oscillators are discussed. The tremendous progress shows that bipolar oxide electronics has evolved from the exploration of various materials and heterostructures to the demonstration of functioning integrated circuits. Therefore a viable, facile and high performance technology is ready for further exploitation and performance optimization. (topical review)

  10. Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

    International Nuclear Information System (INIS)

    Pérez, Juan J.; Pérez-Cajaraville, Juan J.; Muñoz, Víctor; Berjano, Enrique

    2014-01-01

    Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m −1 ) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal

  11. Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief

    Energy Technology Data Exchange (ETDEWEB)

    Pérez, Juan J. [Instituto de Investigación Interuniversitario en Bioingeniería y Tecnología Orientada al Ser Humano, Universitat Politècnica de València, Valencia 46022 (Spain); Pérez-Cajaraville, Juan J. [Pain Unit and Department of Anesthesia and Critical Care, Clínica Universidad de Navarra, University of Navarra, Pamplona 31008 (Spain); Muñoz, Víctor [Neurotherm Spain, Barcelona 08303 (Spain); Berjano, Enrique, E-mail: eberjano@eln.upv.es [Biomedical Synergy, Electronic Engineering Department, Universitat Politècnica de València 46022 (Spain)

    2014-07-15

    Purpose: Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a “strip lesion” to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. Methods: The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. Results: There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m{sup −1}) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. Conclusions: The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of

  12. Computer modeling of electrical and thermal performance during bipolar pulsed radiofrequency for pain relief.

    Science.gov (United States)

    Pérez, Juan J; Pérez-Cajaraville, Juan J; Muñoz, Víctor; Berjano, Enrique

    2014-07-01

    Pulsed RF (PRF) is a nonablative technique for treating neuropathic pain. Bipolar PRF application is currently aimed at creating a "strip lesion" to connect the electrode tips; however, the electrical and thermal performance during bipolar PRF is currently unknown. The objective of this paper was to study the temperature and electric field distributions during bipolar PRF. The authors developed computer models to study temperature and electric field distributions during bipolar PRF and to assess the possible ablative thermal effect caused by the accumulated temperature spikes, along with any possible electroporation effects caused by the electrical field. The authors also modeled the bipolar ablative mode, known as bipolar Continuous Radiofrequency (CRF), in order to compare both techniques. There were important differences between CRF and PRF in terms of electrical and thermal performance. In bipolar CRF: (1) the initial temperature of the tissue impacts on temperature progress and hence on the thermal lesion dimension; and (2) at 37 °C, 6-min of bipolar CRF creates a strip thermal lesion between the electrodes when these are separated by a distance of up to 20 mm. In bipolar PRF: (1) an interelectrode distance shorter than 5 mm produces thermal damage (i.e., ablative effect) in the intervening tissue after 6 min of bipolar RF; and (2) the possible electroporation effect (electric fields higher than 150 kV m(-1)) would be exclusively circumscribed to a very small zone of tissue around the electrode tip. The results suggest that (1) the clinical parameters considered to be suitable for bipolar CRF should not necessarily be considered valid for bipolar PRF, and vice versa; and (2) the ablative effect of the CRF mode is mainly due to its much greater level of delivered energy than is the case in PRF, and therefore at same applied energy levels, CRF, and PRF are expected to result in same outcomes in terms of thermal damage zone dimension.

  13. Cutaneous remodeling and photorejuvenation using radiofrequency devices

    Directory of Open Access Journals (Sweden)

    Elsaie Mohamed

    2009-01-01

    Full Text Available Radio frequency (RF is electromagnetic radiation in the frequency range of 3-300GHz. The primary effects of RF energy on living tissue are considered to be thermal. The goal of the new devices based on these frequency ranges is to heat specific layers of the skin. The directed use of RF can induce dermal heating and cause collagen degeneration. Wound healing mechanisms promote the remodeling of collagen and wound contraction, which ultimately clinically enhances the appearance of mild to moderate skin laxity. Preliminary studies have reported efficacy in the treatment of laxity that involves the periorbital area and jowls. Because RF energy is not dependent on specific chromophore interaction, epidermal melanin is not at risk of destruction and treatment of all skin types is possible. As such, radiofrequency-based systems have been used successfully for nonablative skin rejuvenation, atrophic scar revision and treatment of unwanted hair, vascular lesions and inflammatory acne. The use of RF is becoming more popular, although a misunderstanding exists regarding the mechanisms and limitations of its actions. This concise review serves as an introduction and guide to many aspects of RF in the non ablative rejuvenation of skin.

  14. Treatment of Osteoid Osteomas Using a Navigational Bipolar Radiofrequency Ablation System

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Adam N., E-mail: wallacea@mir.wustl.edu; Tomasian, Anderanik, E-mail: tomasiana@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States); Chang, Randy O., E-mail: changr@wusm.wustl.edu [Washington University School of Medicine (United States); Jennings, Jack W., E-mail: jenningsj@mir.wustl.edu [Washington University School of Medicine, Mallinckrodt Institute of Radiology (United States)

    2016-05-15

    BackgroundPercutaneous CT-guided radiofrequency ablation is a safe and effective minimally invasive treatment for osteoid osteomas. This technical case series describes the use of a recently introduced ablation system with a probe that can be curved in multiple directions, embedded thermocouples for real-time monitoring of the ablation volume, and a bipolar design that obviates the need for a grounding pad.MethodsMedical records of all patients who underwent radiofrequency ablation of an osteoid osteoma with the STAR Tumor Ablation System (DFINE; San Jose, CA) were reviewed. The location of each osteoid osteoma, nidus volume, and procedural details were recorded. Treatment efficacy and long-term complications were assessed at clinical follow-up.ResultsDuring the study period, 18 osteoid osteomas were radiofrequency ablated with the multidirectional bipolar system. Lesion locations included the femur (50 %; 9/18), tibia (22 %; 4/18), cervical spine (11 %; 2/18), calcaneus (5.5 %; 1/18), iliac bone (5.5 %; 1/18), and fibula (5.5 %; 1/18). The median nidus volume of these cases was 0.33 mL (range 0.12–2.0 mL). All tumors were accessed via a single osseous channel. Median cumulative ablation time was 5 min and 0 s (range 1 min and 32 s–8 min and 50 s). All patients with clinical follow-up reported complete symptom resolution. No complications occurred.ConclusionSafe and effective CT-guided radiofrequency ablation of osteoid osteomas can be performed in a variety of locations using a multidirectional bipolar system.

  15. Treatment of Osteoid Osteomas Using a Navigational Bipolar Radiofrequency Ablation System

    International Nuclear Information System (INIS)

    Wallace, Adam N.; Tomasian, Anderanik; Chang, Randy O.; Jennings, Jack W.

    2016-01-01

    BackgroundPercutaneous CT-guided radiofrequency ablation is a safe and effective minimally invasive treatment for osteoid osteomas. This technical case series describes the use of a recently introduced ablation system with a probe that can be curved in multiple directions, embedded thermocouples for real-time monitoring of the ablation volume, and a bipolar design that obviates the need for a grounding pad.MethodsMedical records of all patients who underwent radiofrequency ablation of an osteoid osteoma with the STAR Tumor Ablation System (DFINE; San Jose, CA) were reviewed. The location of each osteoid osteoma, nidus volume, and procedural details were recorded. Treatment efficacy and long-term complications were assessed at clinical follow-up.ResultsDuring the study period, 18 osteoid osteomas were radiofrequency ablated with the multidirectional bipolar system. Lesion locations included the femur (50 %; 9/18), tibia (22 %; 4/18), cervical spine (11 %; 2/18), calcaneus (5.5 %; 1/18), iliac bone (5.5 %; 1/18), and fibula (5.5 %; 1/18). The median nidus volume of these cases was 0.33 mL (range 0.12–2.0 mL). All tumors were accessed via a single osseous channel. Median cumulative ablation time was 5 min and 0 s (range 1 min and 32 s–8 min and 50 s). All patients with clinical follow-up reported complete symptom resolution. No complications occurred.ConclusionSafe and effective CT-guided radiofrequency ablation of osteoid osteomas can be performed in a variety of locations using a multidirectional bipolar system.

  16. Epicardial, Biatrial Ablation With Integrated Uni-bipolar Radiofrequency Technology in Stand-alone Persistent Atrial Fibrillation.

    Science.gov (United States)

    Rosati, Fabrizio; Muneretto, Claudio; Merati, Elisa; Polvani, Gianluca; Moltrasio, Massimo; Tondo, Claudio; Curnis, Antonio; Cerini, Manuel; Metras, Alexandre; Bisleri, Gianluigi

    Although minimally invasive approaches for surgical treatment of stand-alone atrial fibrillation have gained popularity for the past decade, ablation technology and extensive lesion sets play a major role in the achievement of a successful procedure, especially in presence of persistent and long-standing persistent atrial fibrillation. We evaluated clinical outcomes after totally endoscopic biatrial epicardial ablation of persistent atrial fibrillation with a novel integrated uni-bipolar radiofrequency device. Forty-nine (49) consecutive patients with stand-alone atrial fibrillation underwent right-sided monolateral thoracoscopic surgical ablation with a novel integrated uni-bipolar radiofrequency energy delivery and temperature-controlled technology. Atrial fibrillation was persistent in 13 (26.5%) of 49 and long-standing persistent in 36 (73.5%) of 49 patients. Mean ± SD age was 60.6 ± 10.3 years. Median duration of atrial fibrillation was 74 months. Mean ± SD left atrial diameter was 44.7 ± 4.0 mm. Epicardial en bloc isolation of all pulmonary veins (box lesion) and additional ablation of the right atrial free wall was successfully performed via minimally invasive approach without any intraoperative and postoperative major complications. Intraoperative entrance and exit block was achieved in 77.5% (38/49) and 91.8% (45/49) of patients, respectively. Mean ± SD ablation time was 16.3 ± 4.8 minutes. No intensive care unit stay was required. Postoperative sinus rhythm was achieved in 93.8% (30/32) patients, and no pacemaker implantation was required. At 13 months, 87.7% (43/49) of patients were in sinus rhythm; 71.4% (35/49) were free from antiarrhythmic drugs and 75.5% (37/49) from oral anticoagulation. Integrated uni-bipolar radiofrequency ablation technology showed to be effective for the surgical treatment of atrial fibrillation with a total endoscopic approach. A versapolar suction device with extensive right-left atrial lesion set may further improve

  17. Radiofrequency ablation in the liver using two cooled-wet electrodes in the bipolar mode

    International Nuclear Information System (INIS)

    Han, Joon Koo; Lee, Jeong Min; Kim, Se Hyung; Lee, Jae Young; Park, Hee Sun; Eo, Hong; Choi, Byung Ihn

    2005-01-01

    The purpose of this study was to demonstrate the efficacy of bipolar radiofrequency ablation (RFA) using cooled-wet electrodes inducing coagulation in ex vivo bovine livers and in in vivo canine livers. In ex vivo experiments, 20 coagulations were created by monopolar (group A), and bipolar RFA (group B) using a 200 W generator (Valleylab) and one or two cooled-wet electrodes. In in vivo experiments, one coagulation was created by bipolar RFA in each of eight dogs via laparotomy. In ex vivo and in vivo experiments, RF was applied to one or two electrodes at 100 W for 10 min. The dimensions of the coagulations were compared in the two groups. In ex vivo experiments, the mean volumes of the coagulations produced in group B (54.0±16.5 cm 3 ) were greater than those produced in group A (33.9±12.7 cm 3 ) (P=0.007). In in vivo experiments, bipolar RFA produced a coagulation of 39.4±15.6 cm 3 without a major complication. The present study showed that a RF electrode system using two cooled-wet electrodes in the bipolar mode created larger coagulation volumes than the monopolar mode, and this system can be used to create large coagulation without major complications. (orig.)

  18. Imaging the spectral reflectance properties of bipolar radiofrequency-fused bowel tissue

    Science.gov (United States)

    Clancy, Neil T.; Arya, Shobhit; Stoyanov, Danail; Du, Xiaofei; Hanna, George B.; Elson, Daniel S.

    2015-07-01

    Delivery of radiofrequency (RF) electrical energy is used during surgery to heat and seal tissue, such as vessels, allowing resection without blood loss. Recent work has suggested that this approach may be extended to allow surgical attachment of larger tissue segments for applications such as bowel anastomosis. In a large series of porcine surgical procedures bipolar RF energy was used to resect and re-seal the small bowel in vivo with a commercial tissue fusion device (Ligasure; Covidien PLC, USA). The tissue was then imaged with a multispectral imaging laparoscope to obtain a spectral datacube comprising both fused and healthy tissue. Maps of blood volume, oxygen saturation and scattering power were derived from the measured reflectance spectra using an optimised light-tissue interaction model. A 60% increase in reflectance of visible light (460-700 nm) was observed after fusion, with the tissue taking on a white appearance. Despite this the distinctive shape of the haemoglobin absorption spectrum was still noticeable in the 460-600 nm wavelength range. Scattering power increased in the fused region in comparison to normal serosa, while blood volume and oxygen saturation decreased. Observed fusion-induced changes in the reflectance spectrum are consistent with the biophysical changes induced through tissue denaturation and increased collagen cross-linking. The multispectral imager allows mapping of the spatial extent of these changes and classification of the zone of damaged tissue. Further analysis of the spectral data in parallel with histopathological examination of excised specimens will allow correlation of the optical property changes with microscopic alterations in tissue structure.

  19. Meta-analysis of bipolar radiofrequency endometrial ablation versus thermal balloon endometrial ablation for the treatment of heavy menstrual bleeding.

    Science.gov (United States)

    Zhai, Yan; Zhang, Zihan; Wang, Wei; Zheng, Tingping; Zhang, Huili

    2018-01-01

    Heavy menstrual bleeding is a common problem that can severely affect quality of life. To compare bipolar radiofrequency endometrial ablation and thermal balloon ablation for heavy menstrual bleeding in terms of efficacy and health-related quality of life (HRQoL). Online registries were systematically searched using relevant terms without language restriction from inception to November 24, 2016. Randomized control trials or cohort studies of women with heavy menstrual bleeding comparing the efficacy of two treatments were eligible. Data were extracted. Results were expressed as risk ratios (RRs) or weighted mean differences (WMDs) with 95% confidence intervals (CIs). Six studies involving 901 patients were included. Amenorrhea rate at 12 months was significantly higher after bipolar radiofrequency endometrial ablation than after thermal balloon ablation (RR 2.73, 95% CI 2.00-3.73). However, no difference at 12 months was noted for dysmenorrhea (RR 1.04, 95% CI 0.68-1.58) or treatment failure (RR 0.78, 95% CI 0.38-1.60). The only significant difference for HRQoL outcomes was for change in SAQ pleasure score (12 months: WMD -3.51, 95% CI -5.42 to -1.60). Bipolar radiofrequency endometrial ablation and thermal balloon ablation reduce menstrual loss and improve quality of life. However, bipolar radiofrequency endometrial ablation is more effective in terms of amenorrhea rate and SAQ pleasure. © 2017 International Federation of Gynecology and Obstetrics.

  20. Adjuvant Therapy for Revision Rhinoplasty of Contracted Nose Using Polydeoxyribonucleotide and Invasive Bipolar Radiofrequency

    Directory of Open Access Journals (Sweden)

    Tae Hwan Ahn, MD, PhD

    2018-01-01

    Full Text Available Summary:. Most cases of severely contracted nose require revision rhinoplasty and septoplasty, wherein preoperative and/or intraoperative expansion of nasal soft tissue is necessary for tension-free revision surgery. The present study aimed to evaluate the efficacy and safety of pre- and postoperative adjuvant therapy using polydeoxyribonucleotide (PDRN and invasive, pulsed-type, bipolar, alternating current radiofrequency (RF for revision surgery of a contracted nose. In total, 30 patients were treated with 16 sessions (8 preoperative sessions and 8 postoperative sessions of intralesional injection of PDRN and invasive RF treatment using microneedle electrodes at 1-week intervals. One week after the final combined pretreatment using PDRN and invasive bipolar RF, the skin of contracted noses was sufficiently softened, and nasal skin mobility was notably improved in all the patients. During revision rhinoplasty and septoplasty, the contracted nasal skin in each patient was adequately released for proper covering of the nasal tip without tension. Postoperatively, 8 sessions of adjuvant therapy elicited marked clinical improvements in persistent nasal tip dimpling and contracture, septal deviation, and warping from the incomplete recovery of nasal contracture after revision surgery. In conclusion, our pre- and postoperative adjuvant therapies using PDRN and invasive bipolar RF remarkably improved the therapeutic outcomes of revision rhinoplasty and septoplasty for contracted skin of the nose without major side effects.

  1. Transient electro-thermal modeling of bipolar power semiconductor devices

    CERN Document Server

    Gachovska, Tanya Kirilova; Du, Bin

    2013-01-01

    This book presents physics-based electro-thermal models of bipolar power semiconductor devices including their packages, and describes their implementation in MATLAB and Simulink. It is a continuation of our first book Modeling of Bipolar Power Semiconductor Devices. The device electrical models are developed by subdividing the devices into different regions and the operations in each region, along with the interactions at the interfaces, are analyzed using the basic semiconductor physics equations that govern device behavior. The Fourier series solution is used to solve the ambipolar diffusio

  2. Thyroid radiofrequency ablation: Updates on innovative devices and techniques

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hye Sun; Baek, Jung Hwan; Chung, Sae Rom; Choi, Young Jun; Lee, Jeong Hyun [Dept. of Radiology and Research Institute of Radiology, University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of); Park, Auh Whan [Dept. of Radiology, Vascular and Interventional Radiology Section, University of Virginia Health System, Charlottesville (United States)

    2017-08-01

    Radiofrequency ablation (RFA) is a well-known, effective, and safe method for treating benign thyroid nodules and recurrent thyroid cancers. Thyroid-dedicated devices and basic techniques for thyroid RFA were introduced by the Korean Society of Thyroid Radiology (KSThR) in 2012. Thyroid RFA has now been adopted worldwide, with subsequent advances in devices and techniques. To optimize the treatment efficacy and patient safety, understanding the basic and advanced RFA techniques and selecting the optimal treatment strategy are critical. The goal of this review is to therefore provide updates and analysis of current devices and advanced techniques for RFA treatment of benign thyroid nodules and recurrent thyroid cancers.

  3. Laparoscopic resection of a giant exophytic liver haemangioma with the laparoscopic Habib 4× radiofrequency device.

    Science.gov (United States)

    Acharya, Metesh; Panagiotopoulos, Nikolaos; Bhaskaran, Premjithlal; Kyriakides, Charis; Pai, Madhava; Habib, Nagy

    2012-08-27

    Haemangiomas are the most common solitary benign neoplasm of the liver with an incidence ranging from 5% to 20%. Although usually small and asymptomatic, they may reach considerable proportions and rarely give rise to life-threatening complications. Surgical intervention is required for incapacitating symptoms, established complications, and diagnostic uncertainty. The resection of haemangiomas demands meticulous surgical technique, owing to their high vascularity and the concomitant risk of intra-operative haemorrhage. Laparoscopic resection of giant haemangiomas is even more challenging, and has only been reported twice. We here report the case of a giant 10 cm liver haemangioma which was successfully resected laparoscopically using the laparoscopic HabibTM 4×, a bipolar radiofrequency device, without clamping major vessels and with minimal blood loss. Transfusion of blood or blood products was not required. The patient had an uneventful recovery and was asymptomatic at 7-mo follow-up.

  4. Bipolar Radiofrequency Ablation Using Dual Internally Cooled Wet Electrodes: Experimental Study in Ex Vivo Bovine Liver

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Young Joon; Byun, Jae Young [Dept. of Radiology, Seoul St. Mary' s Hospital, The Catholic University of Korea, College of Medicine, Seoul (Korea, Republic of)

    2012-11-15

    To determine the optimized protocol for bipolar radiofrequency ablation (RFA), using dual internally cooled wet (ICW) electrodes in the ex vivo bovine liver. RFA was applied to the explanted bovine liver, using two 3 cm active tip electrodes with 3.5 cm spacing. A total of 25 ablation zones were created by five groups; group A: 70 W-20 minute (min), group B: 70 W-25 min, group C: 90 W-15 min, group D: 90 W-20 min, and group E: 90 W-25 min. We measured the total energy and size of ablation zones with a color of grey or pink. Statistical analysis was done using Kruskal Wallis test and Mann Whitney U-test. The mean energy, mean volume of ablation zone with grey and pink color of groups A to E were 16.7, 23.9, 16.7, 21.8, 29.2 kcal, 25.7, 34.3, 29.5, 36.2, 45.2 cm{sup 3}, and 60.0, 88.0, 71.5, 87.4, 104.5 cm{sup 3}, respectively. Those were significantly different (p < 0.05). The volume of ablation zone of group E with grey color was larger than groups A, B and C (p < 0.05). Bipolar RFA, using dual ICW electrodes, can produce a large ablation zone with the protocol of 90 W-25 min.

  5. Bipolar Radiofrequency Ablation Using Dual Internally Cooled Wet Electrodes: Experimental Study in Ex Vivo Bovine Liver

    International Nuclear Information System (INIS)

    Lee, Young Joon; Byun, Jae Young

    2012-01-01

    To determine the optimized protocol for bipolar radiofrequency ablation (RFA), using dual internally cooled wet (ICW) electrodes in the ex vivo bovine liver. RFA was applied to the explanted bovine liver, using two 3 cm active tip electrodes with 3.5 cm spacing. A total of 25 ablation zones were created by five groups; group A: 70 W-20 minute (min), group B: 70 W-25 min, group C: 90 W-15 min, group D: 90 W-20 min, and group E: 90 W-25 min. We measured the total energy and size of ablation zones with a color of grey or pink. Statistical analysis was done using Kruskal Wallis test and Mann Whitney U-test. The mean energy, mean volume of ablation zone with grey and pink color of groups A to E were 16.7, 23.9, 16.7, 21.8, 29.2 kcal, 25.7, 34.3, 29.5, 36.2, 45.2 cm 3 , and 60.0, 88.0, 71.5, 87.4, 104.5 cm 3 , respectively. Those were significantly different (p < 0.05). The volume of ablation zone of group E with grey color was larger than groups A, B and C (p < 0.05). Bipolar RFA, using dual ICW electrodes, can produce a large ablation zone with the protocol of 90 W-25 min.

  6. Bipolar High-Voltage, Long-Duration Pulsed Radiofrequency Improves Pain Relief in Postherpetic Neuralgia.

    Science.gov (United States)

    Wan, Cheng-Fu; Liu, Yan; Dong, Dao-Song; Zhao, Lin; Xi, Qi; Yu, Xue; Cui, Wen-Yao; Wang, Qiu-Shi; Song, Tao

    2016-07-01

    Postherpetic neuralgia (PHN) is often refractory to existing treatments. Treatment of the dorsal root ganglion (DRG) using monopolar pulsed radiofrequency (PRF), which is a non- or minimally neurodestructive technique, is not efficacious in all patients. This study aimed to determine the safety and clinical efficacy of bipolar high-voltage, long-duration PRF on the DRG in PHN patients. Self before-after controlled clinical trial. Department of Pain Medicine, the First Affiliated Hospital of China Medical University. Ninety patients diagnosed with PHN for > 3months were included. Bipolar high-voltage, long-duration PRF at 42°C for 900 seconds was applied after the induction of paresthesias covered the regions of hyperalgesic skin. The therapeutic effects were evaluated using a visual analog scale (VAS) and the 36-item Short Form health survey (SF-36) before treatment and one, 4, 8, and 12 weeks after PRF. The VAS scores at one, 4, 8, and 12 weeks after PRF treatment were significantly lower than before treatment (P DRG is an effective and safe therapeutic alternative for PHN patients. This treatment could improve the quality of life of PHN patients. NO ChiCTR-OCS-14005461.

  7. Direct Current Combined With Bipolar Radiofrequency Ablation: An Ex Vivo Feasibility Study

    International Nuclear Information System (INIS)

    Tanaka, Toshihiro; Penzkofer, Tobias; Isfort, Peter; Bruners, Philipp; Disselhorst-Klug, Catherine; Junker, Elmar; Kichikawa, Kimihiko; Schmitz-Rode, Thomas; Mahnken, Andreas H.

    2011-01-01

    The combination of radiofrequency ablation (RFA) with direct current (DC) is a promising strategy to improve the efficiency of RFA. However, DC-enhanced monopolar RFA is limited by electrolytic injury at the positive-electrode site. The aim of this study was to investigate the feasibility of the DC-enhanced bipolar RFA. To obviate the need for the subcutaneous positive electrode, the DC circuit was combined with a commercially available bipolar RFA system, in which both poles of the DC circuit are connected to a single RF probe. DC was applied for 15 min and followed by RFA in bovine livers using the following various DC currents: (1) no DC (control), (2) 3V continued until the end of RFA, (3) 5V continued until the end of RFA, (4) 10V continued until the end of RFA, (5) 5V continued in the circuit with reversed pole, (6) 3V stopped after initiation of RFA, and (7) 5V stopped. Coagulation volume, temperatures at a distance of 5, 10, and 15 mm from the RF probe, mean amperage, ablation duration, applied energy, minimum impedance, and degree of tissue charring were assessed and compared (analysis of variance, Student–Newman–Keuls test). All combined DC and RFA groups did increase coagulation volume. The 10V continued group showed significantly lower applied energy, shortest ablation duration, highest minimum impedance, and highest degree of charring with the lowest coagulation volume (p < 0.05). DC-enhanced bipolar RFA with both poles of the DC circuit on a single probe appears to be ineffective.

  8. A trucut biopsy needle for bipolar radiofrequency ablation of needle tract: a proof-of-concept experiment.

    Science.gov (United States)

    Bruners, Philipp; Penzkofer, Tobias; Isfort, Peter; Pfeffer, Jochen; Schmitz-Rode, Thomas; Günther, Rolf W; Mahnken, Andreas H

    2010-08-01

    To develop a trucut biopsy needle featuring two electrodes that allow for bipolar radiofrequency (RF) coagulation of the puncture tract. We modified a 14-G trucut biopsy needle to contain two insulated electrodes and connected the device to an RF generator. Biopsies in ex vivo porcine liver and kidney were performed. The puncture tract was coagulated by using different RF energy settings (5 W, 10 W, 20 W). Tissue specimens were dissected along the puncture tract and the coagulation area was macroscopically evaluated. CT-guided in vivo liver and kidney biopsies were performed in two domestic pigs. Lengths of specimens were measured. Post-biopsy contrast-enhanced CT examinations were performed to rule out biopsy-related bleeding. Animals were euthanised and coagulation areas macroscopically explored. The mean diameters of the coagulated area around the ex vivo biopsy tract were 4.2 +/- 1.1 mm (5 W), 6.0 +/- 2.0 mm (10 W) and 5.2 +/- 0.51 mm (20 W) in liver and 5.0 +/- 0.7 mm (5 W), 6.6 +/- 0.9 (10 W) and 6.0 +/- 2.0 mm (20 W) in kidney. After biopsies CT revealed no bleeding. Mean maximum coagulation diameters were 10.1 +/- 4.6 mm (10 W) in liver and 6.0 +/- 2.5 mm (10 W) in kidney. Mean length of the specimens was 12.2 +/- 4.4 mm in kidney and 11.1 +/- 3.6 mm in liver tissue. Bipolar RF biopsy is a promising tool for tract coagulation after percutaneous biopsy.

  9. A trucut biopsy needle for bipolar radiofrequency ablation of needle tract: a proof-of-concept experiment

    International Nuclear Information System (INIS)

    Bruners, Philipp; Penzkofer, Tobias; Isfort, Peter; Pfeffer, Jochen; Schmitz-Rode, Thomas; Guenther, Rolf W.; Mahnken, Andreas H.

    2010-01-01

    To develop a trucut biopsy needle featuring two electrodes that allow for bipolar radiofrequency (RF) coagulation of the puncture tract. We modified a 14-G trucut biopsy needle to contain two insulated electrodes and connected the device to an RF generator. Biopsies in ex vivo porcine liver and kidney were performed. The puncture tract was coagulated by using different RF energy settings (5 W, 10 W, 20 W). Tissue specimens were dissected along the puncture tract and the coagulation area was macroscopically evaluated. CT-guided in vivo liver and kidney biopsies were performed in two domestic pigs. Lengths of specimens were measured. Post-biopsy contrast-enhanced CT examinations were performed to rule out biopsy-related bleeding. Animals were euthanised and coagulation areas macroscopically explored. The mean diameters of the coagulated area around the ex vivo biopsy tract were 4.2 ± 1.1 mm (5 W), 6.0 ± 2.0 mm (10 W) and 5.2 ± 0.51 mm (20 W) in liver and 5.0 ± 0.7 mm (5 W), 6.6 ± 0.9 (10 W) and 6.0 ± 2.0 mm (20 W) in kidney. After biopsies CT revealed no bleeding. Mean maximum coagulation diameters were 10.1 ± 4.6 mm (10 W) in liver and 6.0 ± 2.5 mm (10 W) in kidney. Mean length of the specimens was 12.2 ± 4.4 mm in kidney and 11.1 ± 3.6 mm in liver tissue. Bipolar RF biopsy is a promising tool for tract coagulation after percutaneous biopsy. (orig.)

  10. Uso da radiofrequência bipolar para o tratamento da fibrilação atrial durante cirurgia cardíaca Uso de la radiofrecuencia bipolar para el tratamiento de la fibrilación atrial durante cirugía cardíaca Use of bipolar radiofrequency for the treatment of atrial fibrillation during cardiac surgery

    Directory of Open Access Journals (Sweden)

    Leonardo Secchin Canale

    2011-06-01

    arritmia. OBJETIVO: Describir la experiencia inicial del Instituto Nacional de Cardiología en el tratamiento quirúrgico de la fibrilación atrial con uso de dispositivo de radiofrecuencia bipolar en pacientes sometidos a cirugía cardíaca, relatando el resultado de seguimiento postoperatorio de un año. MÉTODOS: Entre enero de 2008 y marzo de 2009, 47 pacientes (36 mujeres consecutivos, con edad promedio de 53,7 ± 10,6 años, presentando fibrilación atrial por un período promedio de 34,6 meses (3 a 192 meses fueron sometidos a ablación quirúrgica de esta arritmia, por radiofrecuencia bipolar, durante el procedimiento que motivó la indicación de la cirugía. Ocho presentaban fibrilación atrial intermitente y 39, continua. El 81% fue sometido a cirugía valvular como procedimiento principal. Éste es un análisis retrospectivo, observacional, con evaluación de un año de postoperatorio de las variables clínicas y de Holter 24 h. RESULTADOS: De los 47 pacientes, 40 sobrevivieron un año. De ellos, 33 fueron sometidos a Holter 24 h, en un intervalo promedio de 401 días después de la cirugía. Se encontró la siguiente distribución de ritmos: 24 (73% sinusal, 5 (15% fibrilación atrial, tres (9% flutter atrial y un (3% ritmo de la unión. Se observaron dos accidentes vasculares encefálicos, siendo uno asociado a la arritmia supraventricular. CONCLUSIÓN: La ablación quirúrgica de fibrilación atrial con dispositivo de radiofrecuencia bipolar concomitante a la cirugía cardíaca es método eficaz para el tratamiento de esta arritmia.BACKGROUND: Atrial fibrillation with tissue ablation device through bipolar radiofrequency in conjunction with cardiac surgery has proven to be an effective method to treat this arrhythmia. OBJECTIVE: Describe the initial experience of the Instituto Nacional de Cardiologia in the surgical treatment of atrial fibrillation using bipolar radiofrequency device in patients undergoing cardiac surgery, reporting the results of

  11. A novel non-invasive radiofrequency dermal heating device for skin tightening of the face and neck.

    Science.gov (United States)

    Nelson, Andrew A; Beynet, David; Lask, Gary P

    2015-01-01

    Loose, lax skin is a common cosmetic complaint. Previous non-invasive skin tightening devices had modest efficacy and were associated with pain or downtime. New technologies may allow for effective skin tightening with a series of radiofrequency (RF) treatments with no downtime. To evaluate the efficacy and safety of a novel bipolar RF device for skin tightening. Fifteen consecutive female patients were enrolled in the case series; 14 completed the study and were included in the analysis. The device under investigation is a novel, bipolar RF device allowing for achievement and maintenance of optimal dermal temperatures to stimulate collagen remodeling and skin tightening. Patients underwent a series of 4-6 weekly treatments. Three blinded, experienced cosmetic physicians evaluated paired pre-treatment and post-treatment photographs and determined the associated improvement, if any. All patients (14/14) were determined to have a clinical improvement, as the pre-treatment and post-treatment photographs were correctly identified by the evaluators. It was observed that 21% (3/14) of patients had significant improvement, 50% (7/14) had moderate improvement, and 29% (4/14) had mild improvement. No pain, side effects, or adverse events were observed. This novel bipolar RF device represents a safe, effective treatment option for non-invasive skin tightening.

  12. Therapeutic Efficacy of Bipolar Radiofrequency Thermotherapy for Patients with Chronic Prostatitis: A Retrospective Analysis of 26 Cases

    OpenAIRE

    Lim, Ju Young; Shim, Seung Bum; Yoo, Dong Hoon; Park, Young Woong; Kim, Jong Yeon; Noh, Joon Hwa

    2012-01-01

    Purpose Chronic prostatitis (CP) does not yet have a universally successful therapy. Alternative treatments including thermotherapy have been adopted in the multimodal management of pain and voiding dysfunction. We retrospectively analyzed the therapeutic efficacy of bipolar radiofrequency thermotherapy for patients who were unsatisfied with conventional medication for CP. Materials and Methods A retrospective study between October 2009 and September 2010 of 26 patients who were under 50 year...

  13. Saline-enhanced hepatic radiofrequency ablation using a perfused-cooled electrode: comparison of dual probe bipolar mode with monopolar and single probe bipolar modes

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Lee, Jae Young; Kim, Dae Jin; Lee, Min Woo; Cho, Gyung Goo; Han, Chang Jin; Choi, Byung Ihn

    2004-01-01

    To determine whether saline-enhanced dual probe bipolar radiofrequency ablation (RFA) using perfused-cooled electrodes shows better in-vitro efficiency than monopolar or single probe bipolar RFA in creating larger coagulation necrosis. RF was applied to excised bovine livers in both bipolar and monopolar modes using a 200W generator (CC-3; Radionics) and the perfused-cooled electrodes for 10 mins. After placing single or double perfused-cooled electrodes in the explanted liver, 30 ablation zones were created at three different regimens: group A; saline-enhanced monopolar RFA, group B; saline-enhanced single probe bipolar RFA, and group C; saline-enhanced dual probe bipolar RFA. During RFA, we measured the tissue temperature at 15mm from the electrode. The dimensions of the ablation zones and changes in the impedance currents and liver temperature during RFA were then compared between the groups. The mean current values were higher for monopolar mode (group A) than for the bipolar modes (group B and C): 1550 ± 25 mA in group A, 764 ±189 mA in group B and 819 ± 98 mA in group C(ρ 3 in group A, 23.7 ±3.8 cm 3 in group B, and 34.2 ± 5.1 cm 3 in group C(ρ 0.05). The temperature at 15 mm from the electrode was higher in group C than in the other groups: 70 ± 18 .deg. C in group A, 59 ± 23 .deg. C in group B and 96 ± 16 .deg. C in group C (ρ < 0.05). Saline-enhanced bipolar RFA using dual perfused-cooled electrodes increases the dimension of the ablation zone more efficiently than monopolar RFA or single probe bipolar RFA

  14. The clinical experience and efficacy of bipolar radiofrequency with fractional photothermolysis for aged Asian skin.

    Science.gov (United States)

    Akita, Hirotaka; Sasaki, Ryosuke; Yokoyama, Yusuke; Negishi, Kei; Matsunaga, Kayoko

    2014-10-01

    Bipolar radiofrequency (RF) technology is developed based on fractional thermolysis, and the literature concerning the efficacy of the rejuvenation and treatment of acne scars has been reported in Europe and the United States of America. Therefore, we examined bipolar RF treatment using fractional thermolysis to evaluate the efficacy and safety of the treatment of Asian photo-aging skin, particularly 'wrinkles' and 'sagging.' Ten Japanese women (mean age: 58.6, skin type III-IV) received three fractional bipolar RF treatments every 4-6 weeks. For the objective evaluation, we evaluated the improvement of the wrinkles on the forehead, lateral canthus (crow's feet) and lower eyelid, and the sagging of the nasolabial fold using digital photographs captured using Visia(™) . For the subjective evaluation, the participants were asked to describe the improvements observed in the wrinkles on the forehead, lateral canthus (crow's feet) and lower eyelid, and sagging nasolabial fold and to evaluate the level pain experienced using a 10-point VAS score. The objective evaluation in each category showed significant improvements in the wrinkles on the lateral canthus (crow's feet) and lower eyelid. As for the nasolabial fold, 60% of the subjects showed improvements, scoring from good to excellent (51-100% improvement), although there was a little improvement of the wrinkle on the forehead. Similar improvements were observed in the subjective evaluation. During each treatment, oedema and erythema were observed in all participants, but the oedema disappeared the following day in all cases. However, mild erythema persisted for an average of 3.1 days. Micro debris disappeared after an average of 5.2 days. The participants were satisfied, as we allowed them to apply make-up the next day. There were no other severe adverse reactions observed during the treatment. The 10-point VAS score was 3.8, and no participants dropped out due to discomfort. Little improvement was observed in

  15. Ex vivo human bile duct radiofrequency ablation with a bipolar catheter.

    Science.gov (United States)

    Atar, Mustafa; Kadayifci, Abdurrahman; Daglilar, Ebubekir; Hagen, Catherine; Fernandez-Del Castillo, Carlos; Brugge, William R

    2018-06-01

    Management of the primary and secondary tumors of the bile ducts still remains as a major clinical challenge. Radiofrequency (RF) ablation (RFA) of these tumors is feasible but the effect of RF energy on the human common bile duct (CBD) and surrounding tissues has not been investigated. This pilot study aimed to determine the relationship between RF energy and the depth of ablation in the normal human CBD. The study was performed on fresh ex vivo human biliary-pancreatic tissue which had been resected for a pancreatic cyst or mass. The study was conducted within 15 min after resection. A bipolar Habib RFA catheter was placed into the middle of the intact CBD, and three different (5, 7, 10 W) power settings were applied over a 90-s period by an RF generator. Gross and histological examinations were performed. The depth of coagulation necrosis in CBD and the effect of RFA on CBD wall and surrounding pancreas tissue were determined by microscopic examination. The study included eight tissue samples. 5 W power was applied to three sites and RFA caused only focal epithelial necrosis limited to the CBD mucosa. 7 and 10 W were applied to five sites and coagulation necrosis occurred in all cases. Microscopically, necrosis was transmural, involved accessory bile duct glands, and extended to the surrounding pancreatic tissue in four of these cases. Macroscopically, RFA resulted in circumferential white-yellowish color change extending approximately 2 cm of the CBD. Bipolar RF energy application with 5 W resulted in limited ablation on CBD wall. However, 7 and 10 W generated tissue necrosis which extended through the CBD wall and into surrounding pancreas tissue. Endoscopic biliary RFA is an effective technique for local biliary tissue ablation but the use of high energy may injure surrounding tissue.

  16. Bipolar and monopolar radiofrequency treatment of osteoarthritic knee articular cartilage: acute and temporal effects on cartilage compressive stiffness, permeability, cell synthesis, and extracellular matrix composition.

    Science.gov (United States)

    Cook, James L; Kuroki, Keiichi; Kenter, Keith; Marberry, Kevin; Brawner, Travis; Geiger, Timothy; Jayabalan, Prakash; Bal, B Sonny

    2004-04-01

    The cellular, biochemical, biomechanical, and histologic effects of radiofrequency-generated heat on osteoarthritic cartilage were assessed. Articular cartilage explants (n=240) from 26 patients undergoing total knee arthroplasty were divided based on Outerbridge grade (I or II/III) and randomly assigned to receive no treatment (controls) or monopolar or bipolar radiofrequency at 15 or 30 W. Both potentially beneficial and harmful effects of radiofrequency treatment of articular cartilage were noted. It will be vital to correlate data from in vitro and in vivo study of radiofrequency thermal chondroplasty to determine the clinical usefulness of this technique.

  17. Habib EndoHPB: a novel endobiliary radiofrequency ablation device. An experimental study.

    Science.gov (United States)

    Zacharoulis, Dimitris; Lazoura, Olga; Sioka, Eleni; Potamianos, Spyros; Tzovaras, George; Nicholls, Joanna; Koukoulis, George; Habib, Nagy

    2013-02-01

    The Habib EndoHPB is a bipolar radiofrequency (RF) catheter developed to be introduced across malignant strictures of the bile ducts, so that RF energy can locally ablate the tumor prior to stent placement. This experiment aims to assess the ability of the catheter to coagulate the wall of the common bile duct (CBD) in a porcine model, to establish power requirement and time parameters and correlate them to the depth of thermal injury, and to assess the ease of operation of the device. The CBD was catheterized using the device in 20 pigs. RF energy was applied to the CBD wall with various generator settings. The pigs were sacrificed 24 hr after the application and the CBD was excised for histological analysis. The device was easy to handle. Statistically significant correlations between the power, the time of RF application, and the thermal injury depth were found. The Habib EndoHPB catheter can effectively deliver RF energy intraluminally in the porcine CBD. Clinical studies are warranted in order to define proper settings for safe and efficient use in malignant biliary obstruction.

  18. Face expressive lifting (FEL): an original surgical concept combined with bipolar radiofrequency.

    Science.gov (United States)

    Divaris, Marc; Blugerman, Guillermo; Paul, Malcolm D

    2014-01-01

    Aging can lead to changes in facial expressions, transforming the positive youth expression of happiness to negative expressions as sadness, tiredness, and disgust. Local skin distension is another consequence of aging, which can be difficult to treat with rejuvenation procedures. The "face expressive lifting" (FEL) is an original concept in facial rejuvenation surgery. On the one hand, FEL integrates established convergent surgical techniques aiming to correct the age-related negative facial expressions. On the other hand, FEL incorporates novel bipolar RF technology aiming to correct local skin distension. One hundred twenty-six patients underwent FEL procedure. Facial expression and local skin distension were assessed with 2 years follow-up. There was a correction of negative facial expression for 96 patients (76 %) and a tightening of local skin distension in 100 % of cases. FEL is an effective procedure taking into account and able to correct both age-related negative changes in facial expression and local skin distension using radiofrequency. Level of Evidence: Level IV, therapeutic study.

  19. Enhanced low dose rate radiation effect test on typical bipolar devices

    International Nuclear Information System (INIS)

    Liu Minbo; Chen Wei; Yao Zhibin; He Baoping; Huang Shaoyan; Sheng Jiangkun; Xiao Zhigang; Wang Zujun

    2014-01-01

    Two types of bipolar transistors and nine types bipolar integrated circuit were selected in the irradiation experiment at different "6"0Co γ dose rate. The base current of bipolar transistor and input bias current of amplifier and comparator was measured, low dose enhance factor of test device was obtained. The results show that bipolar device have enhanced low dose rate sensitivity, enhancement factor of bipolar integrated circuit was bigger than that of transistor, and enhanced low dose rate sensitivity greatly varied with different structure and process of bipolar device. (authors)

  20. Evaluation of stray radiofrequency radiation emitted by electrosurgical devices

    International Nuclear Information System (INIS)

    De Marco, M; Maggi, S

    2006-01-01

    Electrosurgery refers to the passage of a high-frequency, high-voltage electrical current through the body to achieve the desired surgical effects. At the same time, these procedures are accompanied by a general increase of the electromagnetic field in an operating room that may expose both patients and personnel to relatively high levels of radiofrequency radiation. In the first part of this study, we have taken into account the radiation emitted by different monopolar electrosurgical devices, evaluating the electromagnetic field strength delivered by an electrosurgical handle and straying from units and other electrosurgical accessories. As a summary, in the worst case a surgeon's hands are exposed to a continuous and pulsed RF wave whose magnetic field strength is 0.75 A m -1 (E-field 400 V m -1 ). Occasionally stray radiation may exceed ICNIRP's occupational exposure guidelines, especially close to the patient return plate. In the second part of this paper, we have analysed areas of particular concern to prevent electromagnetic interference with some life-support devices (ventilators and electrocardiographic devices), which have failed to operate correctly. Most clinically relevant interference occurred when an electrosurgery device was used within 0.3 m of medical equipment. In the appendix, we suggest some practical recommendations intended to minimize the potential for electromagnetic hazards due to therapeutic application of RF energy

  1. Intermediate-term results of partial plantar fascia release with microtenotomy using bipolar radiofrequency microtenotomy.

    Science.gov (United States)

    Lucas, Douglas E; Ekroth, Scott R; Hyer, Christopher F

    2015-01-01

    Plantar fasciitis is a common condition, with most patients treated successfully with nonoperative management. Recalcitrant disease has been managed with surgical procedures that vary in design and associated morbidity. The present study sought to determine the intermediate-term results of percutaneous bipolar radiofrequency microtenotomy in recalcitrant plantar fasciitis. The patient medical records were reviewed, and data were gathered for all the patients who met the inclusion criteria. The foot function index and visual analog scale (VAS) pain scale questionnaires were mailed to the 111 patients. Of the 111 patients, 61 (55.0%) returned their questionnaires and were ultimately included in the present analysis. Of the 61 patients, 44 (72.1%) were female and 17 were (27.9%) male, with an average reported follow-up of 33.3 ± 8.6 (range 16.1 to 46.6) months. The median postoperative VAS score was 0.0 (range 0.0 to 10.0), and the median foot function index score was 3.1 (range 0.0 to 97.1). The patients were subdivided into success and failure groups according to their satisfaction. Of the 61 patients, 51 (83.6%) were satisfied and would recommend the procedure to a friend. The median VAS score in the success group was 0.0 (range 0.0 to 5.0), and the median VAS score in the failure group was 6.0 (range 0.0 to 10.0), a significant difference (p plantar fasciitis. Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

  2. Radiofrequency amplifier based on a DC superconducting quantum interference device

    International Nuclear Information System (INIS)

    Martinis, J.M.; Hilbert, C.; Clarke, J.

    1986-01-01

    A method is described of amplifying a radiofrequency signal consisting of: disposing a single symmetrically biased dc SQUID and an input coil within a superconducting shield, the dc SQUID having a superconducting ring interrupted by two shunted Josephson junctions, and the input coil being inductively coupled solely to the ring of the single SQUID, establishing a constant magnetic flux threading the SQUID ring, applying the radiofrequency signal to the input coil from outside of the superconducting shield, obtaining an amplified radiofrequency signal solely from across the ring of the single SQUID, transmitting the amplified radiofrequency signal from across the SQUID ring to the outside of the superconducting shield

  3. ALINE: A device dedicated to understanding radio-frequency sheaths

    Directory of Open Access Journals (Sweden)

    S. Devaux

    2017-08-01

    Full Text Available In fusion devices, radiofrequency (RF antennas are used for heating the plasma. Those antennas and the plasma interact with each other through the so-called RF sheaths, layers of plasma where the quasi-neutrality breaks down and large electric fields arise. Among the effects of RF sheaths, there is the enhancement of the particles and energy fluxes toward the surface of the antenna, which in turn generate hot spots and release impurities, which are both deleterious for plasma operations. RF sheaths comprehension stumbles on the difficulty to achieve in situ measurements of the sheath properties, as scrape-off layer plasmas are a harsh environment. The very goal of the ALINE device is to tackle this issue and to fulfil the blank between numerical simulations and full-scale experiment by providing measurements within the RF sheaths in a controlled environment. In this paper we report on the latest experimental results from ALINE, in which a cylindrical Langmuir probe mounted on a remotely controlled and programmable arm allows for plasma characterizations in the three dimensions of space around the stainless steel antenna, including the sheath. We present a series of density and potential profiles and three dimension (3D maps in the plasma surrounding a stainless-steel RF antenna as well as in the sheath itself, for unmagnetized and magnetized plasmas.

  4. Experimental animal study of a novel radiofrequency endovascular occlusion device.

    Science.gov (United States)

    Zacharoulis, Dimitris; Lazoura, Olga; Rountas, Christos; Katsimboulas, Michael; Mantzianas, George; Tzovaras, George; Habib, Nagy

    2011-07-01

    The purpose of this study was to present a radiofrequency (RF) endovascular occlusion device (ie, Habib VesCoag Catheter; EMcision Ltd, London, UK) and to evaluate safety and efficacy of the device for complete occlusion of normal porcine vessels. The study included 20 pigs. In each pig, a segmental branch of the right hepatic artery, a branch of the splenic artery, and a branch of one of the renal arteries were catheterized. A single or multiple applications of RF energy were performed until vessel occlusion was achieved. Fifteen days later, angiography was repeated to assess vessel patency. The vessels were then excised for pathological analysis. Vessels 2.5 to 6 mm in diameter were treated. Complete occlusion with a single attempt was achieved using a mean amount of energy of 110.67 J in vessels 2.5 to 3 mm, 111.67 J in vessels 3.5 to 4 mm, and 116.63 J in vessels 5 to 6 mm in diameter and was confirmed by angiography at the 15-day follow-up. Vascular occlusion can be effectively and safely achieved by endovascular application of RF energy to normal porcine arteries using the Habib VesCoag catheter. Copyright © 2011 Elsevier Inc. All rights reserved.

  5. Multicenter Experience with Nonischemic Multiport Laparoscopic and Laparoendoscopic Single-Site Partial Nephrectomy Utilizing Bipolar Radiofrequency Ablation Coagulator

    Directory of Open Access Journals (Sweden)

    Wassim M. Bazzi

    2011-01-01

    Full Text Available Objective. To investigate feasibility of multiport and laparoendoscopic single-site (LESS nonischemic laparoscopic partial nephrectomy (NI-LPN utilizing bipolar radiofrequency coagulator. Methods. Multicenter retrospective review of 60 patients (46 multiport/14 LESS undergoing NI-LPN between 4/2006 and 9/2009. Multiport and LESS NI-LPN utilized Habib 4X bipolar radiofrequency coagulator to form a hemostatic zone followed by nonischemic tumor excision and renorrhaphy. Demographics, tumor/perioperative characteristics, and outcomes were analyzed. Results. 59/60 (98.3% successfully underwent NI-LPN. Mean tumor size was 2.35 cm. Mean operative time was 160.0 minutes. Mean estimated blood loss was 131.4 mL. Preoperative/postoperative creatinine (mg/dL was 1.02/1.07 (=.471. All had negative margins. 12 (20% patients developed complications. 3 (5% developed urine leaks. No differences between multiport and LESS-PN were noted as regards demographics, tumor size, outcomes, and complications. Conclusion. Initial experience demonstrates that nonischemic multiport and LESS-PN is safe and efficacious, with excellent short-term preservation of renal function. Long-term data are needed to confirm oncological efficacy.

  6. Direct Posterior Bipolar Cervical Facet Radiofrequency Rhizotomy: A Simpler and Safer Approach to Denervate the Facet Capsule.

    Science.gov (United States)

    Palea, Ovidiu; Andar, Haroon M; Lugo, Ramon; Granville, Michelle; Jacobson, Robert E

    2018-03-14

    Radiofrequency cervical rhizotomy has been shown to be effective for the relief of chronic neck pain, whether it be due to soft tissue injury, cervical spondylosis, or post-cervical spine surgery. The target and technique have traditionally been taught using an oblique approach to the anterior lateral capsule of the cervical facet joint. The goal is to position the electrode at the proximal location of the recurrent branch after it leaves the exiting nerve root and loops back to the cervical facet joint. The standard oblique approach to the recurrent nerve requires the testing of both motor and sensory components to verify the correct position and ensure safety so as to not damage the slightly more anterior nerve root. Bilateral lesions require the repositioning of the patient's neck. Poorly positioned electrodes can also pass anteriorly and contact the nerve root or vertebral artery. The direct posterior approach presented allows electrode positioning over a broader expanse of the facet joint without risk to the nerve root or vertebral artery. Over a four-year period, direct posterior radiofrequency ablation was performed under fluoroscopic guidance at multiple levels without neuro-stimulation testing with zero procedural neurologic events even as high as the C2 spinal segment. The direct posterior approach allows either unipolar or bipolar lesioning at multiple levels. Making a radiofrequency lesion along the larger posterior area of the facet capsule is as effective as the traditional target point closer to the nerve root but technically easier, allowing bilateral access and safety. The article will review the anatomy and innervation of the cervical facet joint and capsule, showing the diffuse nerve supply extending into the capsule of the facet joint that is more extensive than the recurrent medial sensory branches that have been the focus of radiofrequency lesioning.

  7. Bipolar radiofrequency ablation of liver metastases during laparotomy. First clinical experiences with a new multipolar ablation concept.

    Science.gov (United States)

    Ritz, Joerg-Peter; Lehmann, Kai S; Reissfelder, Christoph; Albrecht, Thomas; Frericks, Bernd; Zurbuchen, Urte; Buhr, Heinz J

    2006-01-01

    Radiofrequency ablation (RFA) is a promising method for local treatment of liver malignancies. Currently available systems for radiofrequency ablation use monopolar current, which carries the risk of uncontrolled electrical current paths, collateral damages and limited effectiveness. To overcome this problem, we used a newly developed internally cooled bipolar application system in patients with irresectable liver metastases undergoing laparotomy. The aim of this study was to clinically evaluate the safety, feasibility and effectiveness of this new system with a novel multipolar application concept. Patients with a maximum of five liver metastases having a maximum diameter of 5 cm underwent laparotomy and abdominal exploration to control resectability. In cases of irresectability, RFA with the newly developed bipolar application system was performed. Treatment was carried out under ultrasound guidance. Depending on tumour size, shape and location, up to three applicators were simultaneously inserted in or closely around the tumour, never exceeding a maximum probe distance of 3 cm. In the multipolar ablation concept, the current runs alternating between all possible pairs of consecutively activated electrodes with up to 15 possible electrode combinations. Post-operative follow-up was evaluated by CT or MRI controls 24-48 h after RFA and every 3 months. In a total of six patients (four male, two female; 61-68 years), ten metastases (1.0-5.5 cm) were treated with a total of 14 RF applications. In four metastases three probes were used, and in another four and two metastases, two and one probes were used, respectively. During a mean ablation time of 18.8 min (10-31), a mean energy of 48.8 kJ (12-116) for each metastases was applied. No procedure-related complications occurred. The patients were released from the hospital between 7 and 12 days post-intervention (median 9 days). The post-interventional control showed complete tumour ablation in all cases. Bipolar

  8. Bipolar radiofrequency ablation of benign thyroid nodules using a multiple overlapping shot technique in a 3-month follow-up.

    Science.gov (United States)

    Kohlhase, Konstantin David; Korkusuz, Yücel; Gröner, Daniel; Erbelding, Christian; Happel, Christian; Luboldt, Wolfgang; Grünwald, Frank

    2016-08-01

    Purpose The aim of this study was to evaluate the decrease of benign thyroid nodules after bipolar radiofrequency ablation (RFA) in a 3-month follow-up using a multiple overlapping shot technique ('MOST'). Methods A total of 18 patients with 20 symptomatic benign thyroid nodules (17 cold nodules, 3 hyperfunctioning nodules) were treated in one single session by bipolar RFA. Bipolar ablation was performed using MOST. The nodule volumes were measured prior to ablation and 3 months after the procedure using ultrasound. The population consisted of either solid (>80% solid tissue within the volume of interest), complex, or cystic nodules (nodule volume (ΔV), median 5.3 mL (range 0.13-43.1 mL), corresponding to a relative reduction in mean of 56 ± 17.9%. Median initial volume was 8 mL (range 0.48-62 mL); 3 months after ablation a median volume of 2.3 mL (range 0.3-32 mL) was measured. Nodule growth ≥50% occurred in 70% (14 nodules). At the follow-up no complications such as infections, persisting pain, nerve injuries or immunogen stimulation occurred. Patients with cold nodules (15) remained euthyroid, with hyperfunctioning nodules either euthyroid (2) or latent hypofunctional (1). Conclusion The use of bipolar RFA is an effective, safe and suitable thermoablative technique to treat benign thyroid nodules. Combined with the multiple overlapping shot technique it allows sufficient ablation.

  9. Comparison of fractional microneedling radiofrequency and bipolar radiofrequency on acne and acne scar and investigation of mechanism: comparative randomized controlled clinical trial.

    Science.gov (United States)

    Min, Seonguk; Park, Seon Yong; Yoon, Ji Young; Suh, Dae Hun

    2015-12-01

    Fractional microneedling radiofrequency (FMR) is one of the promising methods in acne treatment. Moreover, bipolar radiofrequency (BR) generates heat thereby which induces neocollagenosis. FMR may have the potential to be a safe and effective treatment for the patients both with acne and acne scar. This study was performed to compare the efficacy and safety of FMR and BR in acne and acne scar treatment. Furthermore, mechanism of the FMR treatment was investigated through skin tissues obtained from subjects. Twenty subjects with mild-to-moderate acne and acne scars were treated in a split-face manner with FMR and BR. Two sessions of treatment was done 4 weeks apart in a total 12-week prospective single-blind, randomized clinical trial. Clinical assessment and sebum measurement were carried out for the evaluation of efficacy and safety. Skin tissues were acquired for investigation of molecular changes. FMR was more effective for acne scar especially in icepick and boxcar scar compared to BR. Both inflammatory and non-inflammatory acne lesions decreased by 80 and 65 % in the FMR-treated side at the final visit of 12 weeks, respectively. FMR treatment resulted in significant reduction of sebum excretion. Both treatments showed no severe adverse effects other than erythema. The FMR showed superior efficacy in acne and acne scar compared with BR. Increased expression of TGFβ and collagen I and decreased expression of NF-κB, IL-8 are suggested to involve in the improvement of acne scar and acne lesion by FMR.

  10. Facial tightening with an advanced 4-MHz monopolar radiofrequency device.

    Science.gov (United States)

    Taub, Amy F; Tucker, Robert D; Palange, Andrea

    2012-11-01

    Over the past 10 years, radiofrequency (RF) technology has been utilized for nonablative treatments for the treatment of rhytides and skin laxity. This manuscript reviews the scientific background of collagen synthesis in vivo and in response to RF energy as well as a clinical study of 17 patients receiving a series of facial treatments with a 4-MHz monopolar RF (Pellevé, Ellman International, Inc, Oceanside, NY). Clinical methods, results, and a review of the literature for RF aesthetic treatments of the face are presented. Seventeen patients were treated in one site with 6 total treatments scheduled as follows: 1 session was performed every 15 days for 2 consecutive sessions, 1 session every month for 2 consecutive sessions, and 1 session every 2 months for 2 consecutive sessions. Both the treating physician and the patients via live viewing and comparison with baseline photographs performed assessment of results. Results are reported as averages across the 17 patients. Two weeks after the first treatment, patients noted an overall average of 25% to 30% improvement. Just before the last or sixth treatment, there was an average of 50% improvement noted by the physician, with patients ranking an average self-improvement of 48%. The treating physician rated average improvement of 46% compared with baseline, whereas the patients ranked average improvement of 30% compared with baseline at 1 year after treatment was initiated (6 months after the final treatment). Patients find this treatment to be very well tolerated, with minimal to no discomfort and no downtime or significant side effects. The Pellevé 4-MHz monopolar RF device is effective, safe, and very well tolerated for treating laxity, texture, and wrinkles of the skin without complication or discomfort. Evidence in the literature supports the scientific mechanism of action of acute collagen modification and continued neocollagenesis observed with the system. In this cohort, patients maintain approximately 50

  11. CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results

    International Nuclear Information System (INIS)

    Sommer, C. M.; Lemm, G.; Hohenstein, E.; Bellemann, N.; Stampfl, U.; Goezen, A. S.; Rassweiler, J.; Kauczor, H. U.; Radeleff, B. A.; Pereira, P. L.

    2013-01-01

    Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 ± 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 ± 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 ± 13.6 min and 43.7 ± 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 ± 8.8 months, local recurrence-free survival was 14.4 ± 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 ± 16.6 ml/min/1.73 m 2 before RF ablation vs. 47.2 ± 11.9 ml/min/1.73 m 2 after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

  12. CT-guided Bipolar and Multipolar Radiofrequency Ablation (RF Ablation) of Renal Cell Carcinoma: Specific Technical Aspects and Clinical Results

    Energy Technology Data Exchange (ETDEWEB)

    Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Lemm, G.; Hohenstein, E. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany); Bellemann, N.; Stampfl, U. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Goezen, A. S.; Rassweiler, J. [Clinic for Urology, SLK Kliniken Heilbronn GmbH (Germany); Kauczor, H. U.; Radeleff, B. A. [University Hospital Heidelberg, INF 110, Department of Diagnostic and Interventional Radiology (Germany); Pereira, P. L. [Minimally Invasive Therapies and Nuclear Medicine, SLK Kliniken Heilbronn GmbH, Clinic for Radiology (Germany)

    2013-06-15

    Purpose. This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies. Methods. We included 22 consecutive patients (3 women; age 74.2 {+-} 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 {+-} 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated. Results. Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 {+-} 13.6 min and 43.7 {+-} 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 {+-} 8.8 months, local recurrence-free survival was 14.4 {+-} 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 {+-} 16.6 ml/min/1.73 m{sup 2} before RF ablation vs. 47.2 {+-} 11.9 ml/min/1.73 m{sup 2} after RF ablation; not significant). Conclusions. CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

  13. Switching bipolar hepatic radiofrequency ablation using internally cooled wet electrodes: comparison with consecutive monopolar and switching monopolar modes

    Science.gov (United States)

    Yoon, J H; Woo, S; Hwang, E J; Hwang, I; Choi, W; Han, J K; Choi, B I

    2015-01-01

    Objective: To evaluate whether switching bipolar radiofrequency ablation (SB-RFA) using three internally cooled wet (ICW) electrodes can induce coagulations >5 cm in porcine livers with better efficiency than consecutive monopolar (CM) or switching monopolar (SM) modes. Methods: A total of 60 coagulations were made in 15 in vivo porcine livers using three 17-gauge ICW electrodes and a multichannel radiofrequency (RF) generator. RF energy (approximately 200 W) was applied in CM mode (Group A, n = 20) for 24 min, SM mode for 12 min (Group B, n = 20) or switching bipolar (SB) mode for 12 min (Group C, n = 20) in in vivo porcine livers. Thereafter, the delivered RFA energy, as well as the shape and dimension of coagulations were compared among the groups. Results: Spherical- or oval-shaped ablations were created in 30% (6/20), 85% (17/20) and 90% (18/20) of coagulations in the CM, SM and SB groups, respectively (p = 0.003). SB-RFA created ablations >5 cm in minimum diameter (Dmin) in 65% (13/20) of porcine livers, whereas SM- or CM-RFA created ablations >5 cm in only 25% (5/20) and 20% (4/20) of porcine livers, respectively (p = 0.03). The mean Dmin of coagulations was significantly larger in Group C than in Groups A and B (5.1 ± 0.9, 3.9 ± 1.2 and 4.4 ± 1.0 cm, respectively, p = 0.002) at a lower delivered RF energy level (76.8 ± 14.3, 120.9 ± 24.5 and 114.2 ± 18.3 kJ, respectively, p 5 cm in diameter with better efficiency than do SM- or CM-RFA. Advances in knowledge: SB-RFA can create large, regular ablation zones with better time–energy efficiency than do CM- or SM-RFA. PMID:25873479

  14. Radiofrequency Thermal Ablation versus Bipolar Electrocautery for the Treatment of Inferior Turbinate Hypertrophy: Comparison of Efficacy and Postoperative Morbidity

    Directory of Open Access Journals (Sweden)

    Uluyol, Sinan

    2015-04-01

    Full Text Available Introduction Numerous surgical methods are used to treat nasal obstruction due to inferior turbinate hypertrophy. The primary goal of the therapy is to maximize the nasal airway for as extended a period of time as possible while minimizing therapeutic complications. Objectives The aim of this study was to assess the effects of radiofrequency thermal ablation (RFTA and bipolar electrocautery (BEC on the removal of nasal obstruction in patients with inferior turbinate hypertrophy and on nasal mucociliary clearance (MCC. Patients in both groups were also evaluated in terms of postoperative morbidity. Methods We compared the outcomes of two groups of patients: those treated with RFTA (n = 23 and those who underwent BEC (n = 20. Nasal obstruction was graded using a visual analog scale (VAS and MCC was measured using a saccharin clearance test. Both measurements were performed before and 2 months after treatment. Results Pre- and postoperative VAS scores showed significant improvement for both groups. However, MCC results did not significantly differ between two groups. Neither edema nor crust formation persisted for more than 1 week in any patients. Conclusion Submucosal cauterization with preservation of the nasal mucosa and periosteum is as effective and safe as RFTA and should be considered when planning inferior turbinate interventions.

  15. New-generation radiofrequency technology.

    Science.gov (United States)

    Krueger, Nils; Sadick, Neil S

    2013-01-01

    Radiofrequency (RF) technology has become a standard treatment in aesthetic medicine with many indications due to its versatility, efficacy, and safety. It is used worldwide for cellulite reduction; acne scar revision; and treatment of hypertrophic scars and keloids, rosacea, and inflammatory acne in all skin types. However, the most common indication for RF technology is the nonablative tightening of tissue to improve skin laxity and reduce wrinkles. Radiofrequency devices are classified as unipolar, bipolar, or multipolar depending on the number of electrodes used. Additional modalities include fractional RF; sublative RF; phase-controlled RF; and combination RF therapies that apply light, massage, or pulsed electromagnetic fields (PEMFs). This article reviews studies and case series on these devices. Radiofrequency technology for aesthetic medicine has seen rapid advancements since it was used for skin tightening in 2003. Future developments will continue to keep RF technology at the forefront of the dermatologist's armamentarium for skin tightening and rejuvenation.

  16. Evaluation of microneedling fractional radiofrequency device for treatment of acne scars

    Directory of Open Access Journals (Sweden)

    Byalekere Shivanna Chandrashekar

    2014-01-01

    Full Text Available Background: Various treatment modalities including non-invasive methods such as chemical peels, topical retinoids, microdermabrasion, minimally invasive techniques such as microneedling, fractional lasers, microneedling radiofrequency devices and invasive procedures such as acne scar surgeries and ablative lasers are used for acne scars, each with its own unique advantages and disadvantages. This study is a retrospective assessment of efficacy and safety of microneedling fractional radiofrequency in the treatment of acne scars. Methods: Thirty one patients of skin types III-V with moderate and severe facial acne scarring received four sequential fractional radiofrequency treatments over a period of 6 months with an interval of 6 weeks between each session. Goodman & Baron′s acne scar grading system was used for assessment by a side by side comparison of preoperative and post- operative photographs taken at their first visit and at the end of 3 months after the last session. Results: Estimation of improvement with Goodman and Baron′s Global Acne Scarring System showed that by qualitative assessment of 31 patients with grade 3 and grade 4 acne scars, 80.64% showed improvement by 2 grades and 19.35% showed improvement by 1 grade. Quantitative assessment showed that 58% of the patients had moderate, 29% had minimal, 9% had good and 3% showed very good improvement. Adverse effects were limited to transient pain, erythema, edema and hyperpigmentation. Conclusion: Microneedling fractional radiofrequency is efficacious for the treatment of moderate and severe acne scars.

  17. No-touch radiofrequency ablation: A comparison of switching bipolar and switching monopolar ablation in Ex Vivo bovine liver

    International Nuclear Information System (INIS)

    Chang, Won; Lee, Jeong Min; Lee, Sang Min; Hank, Joon Koo

    2017-01-01

    To evaluate the feasibility, efficiency, and safety of no-touch switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) using ex vivo bovine livers. A pork loin cube was inserted as a tumor mimicker in the bovine liver block; RFA was performed using the no-touch technique in the SM (group A1; 10 minutes, n = 10, group A2; 15 minutes, n = 10) and SB (group B; 10 minutes, n = 10) modes. The groups were compared based on the creation of confluent necrosis with sufficient safety margins, the dimensions, and distance between the electrode and ablation zone margin (DEM). To evaluate safety, small bowel loops were placed above the liver surface and 30 additional ablations were performed in the same groups. Confluent necroses with sufficient safety margins were created in all specimens. SM RFA created significantly larger volumes of ablation compared to SB RFA (all p < 0.001). The DEM of group B was significantly lower than those of groups A1 and A2 (all p < 0.001). Although thermal injury to the small bowel was noted in 90%, 100%, and 30% of the cases in groups A1, A2, and B, respectively, full depth injury was noted only in 60% of group A2 cases. The no-touch RFA technique is feasible in both the SB and SM modes; however, SB RFA appears to be more advantageous compared to SM RFA in the creation of an ablation zone while avoiding the unnecessary creation of an adjacent parenchymal ablation zone or adjacent small bowel injuries

  18. No-touch radiofrequency ablation: A comparison of switching bipolar and switching monopolar ablation in Ex Vivo bovine liver

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Won; Lee, Jeong Min; Lee, Sang Min; Hank, Joon Koo [Dept. of Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2017-04-15

    To evaluate the feasibility, efficiency, and safety of no-touch switching bipolar (SB) and switching monopolar (SM) radiofrequency ablation (RFA) using ex vivo bovine livers. A pork loin cube was inserted as a tumor mimicker in the bovine liver block; RFA was performed using the no-touch technique in the SM (group A1; 10 minutes, n = 10, group A2; 15 minutes, n = 10) and SB (group B; 10 minutes, n = 10) modes. The groups were compared based on the creation of confluent necrosis with sufficient safety margins, the dimensions, and distance between the electrode and ablation zone margin (DEM). To evaluate safety, small bowel loops were placed above the liver surface and 30 additional ablations were performed in the same groups. Confluent necroses with sufficient safety margins were created in all specimens. SM RFA created significantly larger volumes of ablation compared to SB RFA (all p < 0.001). The DEM of group B was significantly lower than those of groups A1 and A2 (all p < 0.001). Although thermal injury to the small bowel was noted in 90%, 100%, and 30% of the cases in groups A1, A2, and B, respectively, full depth injury was noted only in 60% of group A2 cases. The no-touch RFA technique is feasible in both the SB and SM modes; however, SB RFA appears to be more advantageous compared to SM RFA in the creation of an ablation zone while avoiding the unnecessary creation of an adjacent parenchymal ablation zone or adjacent small bowel injuries.

  19. Studying the thermal performance of a bipolar radiofrequency ablation with an improved electrode matrix system: In vitro experiments and modelling

    International Nuclear Information System (INIS)

    Shao, Y.L.; Leo, H.L.; Chua, K.J.

    2017-01-01

    Highlights: • We made judicious modification to the Penne’s equation in the process of developing our model. We consider the liver to consist of tumor and health tissue. The model has been validated with experimental data. • The proposed electrode system can reduce the tissue volume damage outside the electrodes. The designed building unit with 10 mm inter-electrode distance is the optimal choice to achieve desired ablation zone. • The influence of blood vessel is relatively small for using this electrode system. A spatial distance of 13 mm is deemed as the safe distance between the wall of the central probe and the large vessel. • This proposed electrode system demonstrated higher ablation stability even for tissue regions that are close to blood vessels. The system is better suited for matrix-type RFA. - Abstract: Radiofrequency ablation (RFA) is becoming an effective treatment method for both primary tumors and tumors that have metastasized. Large tumors in difficult anatomic locations can be treated by RFA technologies. However, constant size and regular shape of damage zones cannot be obtained by recent RFA technologies. The aim of this study is to optimize the stability of RFA treatment by employing a newly proposed bipolar electrode system. A hepatic RFA mathematical model is developed by the finite element method approach. The model is validated with the experimental data. This model is then used to verify the reliability and stability of the proposed electrode system. Simulated results showed the cross section of the ablation zone utilizing designed electrode system approximates a square. In addition, the fraction of the necrosed tissue with this electrode pattern turned out to be larger than the fraction with single-probe RFA techniques. This system demonstrated higher ablation stability even for tissue regions that are close to blood vessels. The proposed electrode system is better suited for matrix-type RFA.

  20. Therapeutic efficacy of bipolar radiofrequency thermotherapy for patients with chronic prostatitis: a retrospective analysis of 26 cases.

    Science.gov (United States)

    Lim, Ju Young; Shim, Seung Bum; Yoo, Dong Hoon; Park, Young Woong; Kim, Jong Yeon; Noh, Joon Hwa

    2012-07-01

    Chronic prostatitis (CP) does not yet have a universally successful therapy. Alternative treatments including thermotherapy have been adopted in the multimodal management of pain and voiding dysfunction. We retrospectively analyzed the therapeutic efficacy of bipolar radiofrequency thermotherapy for patients who were unsatisfied with conventional medication for CP. A retrospective study between October 2009 and September 2010 of 26 patients who were under 50 years old and diagnosed with CP (National Institutes of Health [NIH]-category III) was performed. Twenty patients were diagnosed with inflammatory CP (NIH-category IIIa) and the rest with noninflammatory CP (NIH-category IIIb). We used the Tempro system at an intraprostatic temperature of 55℃ for 50 minutes with a medium heating rate. All patients also completed the NIH-Chronic Prostatitis Symptom Index (CPSI) before and after treatment. In the patients diagnosed with CP, the mean serum prostate-specific antigen (PSA) level was 0.9±0.3 ng/ml, the prostate volume was 27.1±5.5 g, and the average score for all 3 domains on the NIH-CPSI significantly decreased. The total scores decreased from 19.8±7.1 to 11.1±7.0, the pain domain decreased from 8.6±3.1 to 4.8±3.1, the voiding symptom domain decreased from 5.1±1.8 to 2.9±1.8, and the effect on the quality of life decreased from 6.1±2.2 to 3.4±2.2 (pthermotherapy for patients with CP intractable to conventional medication can provide significant improvement in the NIH-CPSI. Large, randomized controlled trials will also be required to confirm the efficacy of this therapy.

  1. Internally gas-cooled radiofrequency applicators as an alternative to conventional radiofrequency and microwave ablation devices: An in vivo comparison

    Energy Technology Data Exchange (ETDEWEB)

    Rempp, Hansjörg, E-mail: Hansjoerg.rempp@med.uni-tuebingen.de [Eberhard Karls University of Tübingen, Tübingen University Hospital, Department of Diagnostic and Interventional Radiology, Hoppe-Seyler-Straße 3, Tübingen, 72076 (Germany); Voigtländer, Matthias [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Schenk, Martin [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Enderle, Markus D. [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); Scharpf, Marcus [Eberhard Karls University of Tuebingen, Insitute of Pathology, Department on General Pathology and Pathological Anatomy, Liebermeisterstraße 8, 72076 Tübingen (Germany); Greiner, Tim O. [Eberhard Karls University of Tuebingen, Tübingen University Hospital, Department of General, Visceral and Transplant Surgery, Hoppe-Seyler-Straße 3, 72076 Tübingen (Germany); Neugebauer, Alexander [ERBE Elektromedizin GmbH, Waldhörnlestraße 17, 72072 Tübingen (Germany); and others

    2013-08-15

    Purpose: To test the efficacy of internally CO{sub 2}-cooled radiofrequency (RF) ablation in vivo and to compare its effectiveness to a standard water-cooled RF probe and to a gas-cooled microwave (MW) device. Method and materials: 49 ablations were performed on 15 pigs under general anesthesia using 15G monopolar CO{sub 2}-cooled RF applicators, 17G monopolar water-cooled RF applicators and 15G internally CO{sub 2}-cooled microwave devices. The power of the MW device was 45 W, the current of the gas-cooled RF device was 1200–1600 mA. At the water-cooled RF probe, maximum power of 200 W was set. Ablation time was 15 min. The short and long axes of the ablation zone were measured. Histological analyses and NADH-staining were performed. The diameters and the ablation volumes were compared using an analysis of variance. Results: No spots of untreated tissue were observed close to the cooled needle track in any of the ablation zones. The largest short axis diameter was 3.4 ± 0.5 cm achieved with the gas-cooled monopolar applicator. With the water-cooled applicators, short axis diameter was significantly smaller, reaching 2.5 ± 0.4 cm. Gas-cooled MW probes achieved 2.9 ± 1.0 cm. The largest ablation volume was 31.5 ± 12 ml (gas-cooled RF), and the smallest was 12.7 ± 4 ml (water-cooled RF). Short/long axis ratio was largest for gas-cooled RF probes with 0.73 ± 0.08 versus 0.64 ± 0.04 for the water-cooled probes and 0.49 ± 0.25 for the microwave applicator. Conclusion: Gas-cooled RF applicators may have a higher potential for effective destruction of liver lesions than comparable water-cooled RF systems, and may be an alternative to standard RF and MW ablation devices.

  2. Clinical efficacy and safety evaluation of a novel fractional unipolar radiofrequency device on facial tightening: A preliminary report.

    Science.gov (United States)

    Suh, Dong Hye; Byun, Eun Jung; Lee, Sang Jun; Song, Kye Yong; Kim, Hei Sung

    2017-06-01

    Previous studies have shown that radiofrequency (RF) energy is safe and effective for improving skin laxity. Unlike monopolar and bipolar devices, little has been studied with the unipolar hand piece. We sought to evaluate the safety and efficacy of a novel fractional unipolar RF device on facial tightening. This was a retrospective, single-center study of 14 subjects with age-related facial laxity who underwent five sessions of fractional unipolar RF at an interval of 2 weeks, and then followed-up for 3 months. Standardized photos were taken at baseline and at 3-months follow-up, and were assessed by two independent dermatologists using a 4-point scale (0=no improvement, 1=mild improvement, 2=moderate improvement, 3=significant improvement). Punch biopsies (2 mm) were performed and a questionnaire was used to evaluate the patient's satisfaction and the incidence of adverse reactions. Fourteen subjects with mild to moderate age-related facial laxity were included in the study. The mean age of the subjects was 49.7 years (range 32-80). 35.7% of the subjects showed significant improvement, 50% moderate improvement, and 14.3% slight improvement of facial laxity in their follow-up photos. About 85.7% of the patients replied that they were either greatly satisfied or satisfied with the results at 3-months follow-up. Skin biopsies revealed an increase in collagen in the dermis. None of the subjects experienced any serious adverse events during or after the procedure. Our findings suggest that fractional Unipolar RF can be safely performed on the face and is effective in skin tightening. It has a great advantage over other forms of RF by being entirely painless. © 2017 Wiley Periodicals, Inc.

  3. Using temperature-switching approach to evaluate the ELDRS of bipolar devices

    Science.gov (United States)

    Li, Xiaolong; Lu, Wu; Wang, Xin; Guo, Qi; Yu, Xin; He, Chengfa; Sun, Jing; Liu, Mohan; Yao, Shuai; Wei, Xinyu

    2017-12-01

    Enhanced low-dose rate sensitivity (ELDRS) exhibited at low-dose rates (LDRs) by most bipolar devices is considered as one of the main concerns for spacecraft reliability. In this work, a time-saving and conservative approach - temperature-switching approach (TSA) - to simulate the ELDRS of bipolar devices is presented. Good agreement is observed between the predictive curve obtained with the TSA and the LDR data, and TSA provides us with a new insight into the test technique for ELDRS. Additionally, the mechanisms of TSA are analyzed in this paper.

  4. A comparative experimental study of the in-vitro efficiency of hypertonic saline-enhanced hepatic bipolar and monopolar radiofrequency ablation

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Han, Joon Koo; Kim, Se Hyung; Sohn, Kyu Li; Lee, Kyoung Ho; Ah, Su Kyung; Choi, Byung Ihn

    2003-01-01

    To compare the in-vitro efficiency of a hypertonic saline (HS)- enhanced bipolar radiofrequency (RF) system with monopolar RF applications by assessing the temperature profile and dimensions of RF-created coagulation necrosis in bovine liver. A total of 27 ablations were performed in explanted bovine livers. After placement of two 16-gauge open-perfused electrodes at an interelectrode distance of 3 cm, 5% HS was instilled into tissue at a rate of 1 mL/min through the electrode. Seventeen thermal ablation zones were created in the monopolar mode (groups A, B), and ten more were created using the two open-perfused electrodes in the bipolar mode (group C). RF was applied to each electrode for 5 mins (for a total of 10 mins, group A) or 10 mins (for a total of 20 mins, group B) at 50W in the sequential monopolar mode, or to both electrodes for 10 min in the bipolar mode (group C). During RF instillation, we measured tissue temperature at the midpoint between the two electrodes. The dimensions of the thermal ablation zones and changes in impedance and wattage during RFA were compared between the groups. With open-perfusion electrodes, the mean accumulated energy output value was lower in the bipolar mode (group C: 26675±3047 Watt's) than in the monopolar mode (group A: 28778±1300 Watt's) but the difference was not statistically significant (p > 0.05). In the bipolar mode, there were impedance rises of more than 700 Ω during RF energy application, but in the monopolar modes, impedance did not changed markedly. In the bipolar mode, however, the temperature at the mid-point between the two probes was higher (85 .deg. C) than in the monopolar modes (65 .deg. C, 80 .deg. C for group A, B, respectively) (p<0.05). In addition, in HS-enhanced bipolar RFA (group C), the shortest diameter at the midpoint between the two electrodes was greater than in either of the monopolar modes: 5.4±5.6 mm (group A); 28.8±8.2 mm (group B); 31.2±7.6 mm (group C) (p<0.05) Using an open

  5. What are the benefits and risks of fitting patients with radiofrequency identification devices.

    Directory of Open Access Journals (Sweden)

    Mark Levine

    2007-11-01

    Full Text Available In 2004, the United States Food and Drug Administration approved a radiofrequency identification (RFID device that is implanted under the skin of the upper arm of patients and that stores the patient's medical identifier. When a scanner is passed over the device, the identifier is displayed on the screen of an RFID reader. An authorized health professional can then use the identifier to access the patient's clinical information, which is stored in a separate, secure database. Such RFID devices may have many medical benefits--such as expediting identification of patients and retrieval of their medical records. But critics of the technology have raised several concerns, including the risk of the patient's identifying information being used for nonmedical purposes.

  6. What are the benefits and risks of fitting patients with radiofrequency identification devices.

    Science.gov (United States)

    Levine, Mark; Adida, Ben; Mandl, Kenneth; Kohane, Isaac; Halamka, John

    2007-11-27

    In 2004, the United States Food and Drug Administration approved a radiofrequency identification (RFID) device that is implanted under the skin of the upper arm of patients and that stores the patient's medical identifier. When a scanner is passed over the device, the identifier is displayed on the screen of an RFID reader. An authorized health professional can then use the identifier to access the patient's clinical information, which is stored in a separate, secure database. Such RFID devices may have many medical benefits--such as expediting identification of patients and retrieval of their medical records. But critics of the technology have raised several concerns, including the risk of the patient's identifying information being used for nonmedical purposes.

  7. Ex Vivo Experiment of Saline-Enhanced Hepatic Bipolar Radiofrequency Ablation with a Perfused Needle Electrode: Comparison with Conventional Monopolar and Simultaneous Monopolar Modes

    International Nuclear Information System (INIS)

    Lee, Jeong Min; Kim, Se Hyung; Han, Joon Koo; Sohn, Kyu Li; Choi, Byung Ihn

    2005-01-01

    The purpose of this study was to validate the saline-enhanced bipolar radiofrequency ablation (RFA) technique using a perfused electrode to increase RF-created coagulation necrosis, to compare that technique with monopolar RFAs and to find appropriate concentrations and volumes of perfused NaCl solution for the bipolar RFA. A total of 90 ablations were performed in explanted bovine livers. In the initial experiments to determine appropriate conditions for bipolar RFA, we created five thermal ablation zones in each condition, with instillations of varied concentrations (0.9-36%) or injection rates (30 mL/hr-120 mL/hr) of NaCl solution. After placement of one or two 16-gauge open-perfused electrodes into bovine livers, the NaCl solution was instilled into the tissue through the electrode. In the second part of the study, 10 ablation zones were created using one or two perfused electrodes for each of five groups under different conditions: a conventional monopolar mode with 0.9% NaCl solution (group A) or with 6% NaCl solution (group B), a simultaneous monopolar mode with 6% NaCl solution (group C) and a bipolar mode with 6% NaCl solution (groups D and E). RF was applied to each electrode for 20 min in groups A, B, C, and E, or for 10 min in group D. During RFA, we measured the tissue temperature 15 mm from the electrode. The temperature changes during the RFA and the dimensions of the ablation zones were compared among the groups. Bipolar RFA created larger short-axis diameters of coagulation necrosis with 6% NaCl solution (35.8 ± 15 mm) than with 0.9% NaCl solution (17 ± 9.7 mm) (P 0.05): 31.0 ± 5.4 mm (group A); 28.8 ± 3.8 mm (group B); 25.5 ± 6.4 mm (group C); 32.6 ± 4.2 mm (group D); 49.4 ± 5.0 mm (group E). Bipolar RFA with instillation of 6% NaCl solution through an open perfusion system demonstrates better efficacy in creating a larger ablation zone than does conventional or simultaneous monopolar modes at the various times examined. Therefore

  8. Deep ion implantation for bipolar silicon devices; investigations into the use of the third dimension

    International Nuclear Information System (INIS)

    Mouthaan, A.J.

    1986-01-01

    This thesis covers various aspects of the use of deep ion implantations in digital bipolar circuits. It starts with the implications of the use of deep ion implantations for numerical process, device and circuit simulation. It shows the use of 1MeV boron and phosphorus implantations in the realization of a fully vertical IIL, here named Buried Injector Logic, which can also be used as static and dynamic memory device in several different configurations. The author presents a combined MOS-bipolar device, called the Charge Injection Device as a dynamic memory cell. Finally, deep ion implantations are used to realize a stack of photovoltaic cells that produces a multiple of the open circuit voltage of one photodiode. (Auth.)

  9. One bipolar transistor selector - One resistive random access memory device for cross bar memory array

    Science.gov (United States)

    Aluguri, R.; Kumar, D.; Simanjuntak, F. M.; Tseng, T.-Y.

    2017-09-01

    A bipolar transistor selector was connected in series with a resistive switching memory device to study its memory characteristics for its application in cross bar array memory. The metal oxide based p-n-p bipolar transistor selector indicated good selectivity of about 104 with high retention and long endurance showing its usefulness in cross bar RRAM devices. Zener tunneling is found to be the main conduction phenomena for obtaining high selectivity. 1BT-1R device demonstrated good memory characteristics with non-linearity of 2 orders, selectivity of about 2 orders and long retention characteristics of more than 105 sec. One bit-line pull-up scheme shows that a 650 kb cross bar array made with this 1BT1R devices works well with more than 10 % read margin proving its ability in future memory technology application.

  10. Características construtivas e funcionais das agulhas de radiofrequência bipolares resfriadas para reduzir o sangramento nas ressecções hepáticas Construction of radiofrequency cold bipolar needles and its functional aspects to reduce the bleeding in hepatic resections

    Directory of Open Access Journals (Sweden)

    José Artur Sampaio

    2011-06-01

    Full Text Available RACIONAL: Para diminuir o sangramento em ressecções hepáticas diversas opções tecnológicas têm sido divulgadas, dentre elas a radiofrequência. A intenção dos vários métodos é evitar o clampeamento vascular, fazer menor dissecção hepática e obter menor sangramento. OBJETIVO: Apresentar uma nova técnica de agulhas paralelas de radiofrequência bipolar desenvolvidas pelos próprios autores e os detalhes técnicos de seu uso. MÉTODOS: O sistema de agulhas apresenta dois eletrodos paralelos (18 gauge cada de 25 cm de comprimento, separados entre si por uma distância de 1,5 cm, onde apenas os 4 cm distais dissipam energia gerada por um eletrobisturi bipolar. Estas agulhas são refrigeradas através de um sistema de resfriamento interno por fluxo contínuo de água destilada gelada estéril a 0oC, cuja temperatura é mantida através da presença de gelo, formado também por água destilada estéril. A operação é realizada sob anestesia geral, não sendo utilizados cateteres venosos centrais durante ou após o procedimento. As incisões realizadas podem ser subcostal direita e mediana supra-umbilical. RESULTADOS: A experiência inicial de sua utilização nas ressecções hepáticas mostraram média de 87 minutos, tamanho médio da incisão abdominal de 14 cm e sangramento médio de 58 ml. Nenhum paciente do grupo inicial recebeu transfusão de sangue ou derivados. CONCLUSÃO: As agulhas de radiofrequência bipolares resfriadas são viáveis e reduzem o sangramento nas ressecções hepáticas.BACKGROUND: To reduce bleeding in liver resection various technological options have been disclosed, among them the radiofrequency. The intent of the various methods is to avoid vascular clamping, less liver dissection and minimize bleeding. AIM: To present a new technique of parallel bipolar radiofrequency needles developed by the authors and the technical details. METHODS: The needle system has two parallel electrodes (18 gauge each of 25

  11. Effects of emitter junction and passive base region on low dose rate effect in bipolar devices

    International Nuclear Information System (INIS)

    Pershenkov, V.S.; Cherepko, S.V.; Maslov, V.B.; Belyakov, V.V.; Sogoyan, A.V.; Ulimov, N.; Emelianov, V.V.

    1999-01-01

    Low dose rate effect in bipolar devices consists in the increase of peripheral surface recombination current with dose rate decrease. This is due to the more rapid positive oxide charge and interface trap density build-up as the dose rate becomes lower. High dose rate elevated temperature irradiation is proposed for simulation if the low dose rate effect. In the present we tried to separate the effect of radiation-induced charge in the thick passivation oxide over the emitter junction and passive base regions of npn bipolar transistor. Its goal is to improve bipolar device design for use in space environments and nuclear installations. Three experiments were made during this work. 1. Experiment on radiation-induced charge neutralization (RICN) effect under elevated temperature was performed to show transistor degradation dependence on emitter-base bias. 2. High dose rate elevated and room temperature irradiation of bipolar transistors were performed to separate effects of emitter-junction and passive base regions. 3. Pre- and post- irradiation hydrogen ambient storage was used to investigate its effect on radiation-induced charge build-up over the passive base region. All experiments were performed with npn and pnp transistors. (authors)

  12. Circumference reduction and cellulite treatment with a TriPollar radiofrequency device: a pilot study.

    Science.gov (United States)

    Manuskiatti, W; Wachirakaphan, C; Lektrakul, N; Varothai, S

    2009-07-01

    A wide variety of treatments for circumference reduction and cellulite are available, but most procedures offer suboptimal clinical effect and/or delayed therapeutic outcome. Objective To determine the safety and efficacy of the TriPollar radiofrequency device for cellulite treatment and circumference reduction. Thirty-nine females with cellulite received eight weekly TriPollar treatments. Treatment areas included the abdomen, thighs, buttocks and arms. Subjects were evaluated using standardized photographs and measurements of body weight, circumference, subcutaneous thickness, and skin elasticity of the treatment sites at baseline, immediately after and 4 weeks after the final treatment. Physicians' evaluation of clinical improvement scores using a quartile grading scale was recorded. Thirty-seven patients (95%) completed the treatment protocol. There was significant circumference reduction of 3.5 and 1.7 cm at the abdomen (P = 0.002) and thigh (P = 0.002) regions, respectively. At 4 weeks after the last treatment, the average circumferential reductions of the abdomen and thighs were sustained. No significant circumferential reductions of the buttocks and arms at the last treatment visit compared to baseline were demonstrated (P = 0.138 and 0.152, respectively). Quartile grading scores correlating to approximately 50% improvement in cellulite appearance were noted. Tripollar radiofrequency provided beneficial effects on the reduction of abdomen and thigh circumference and cellulite appearance.

  13. Rapid, Sensitive, and Reusable Detection of Glucose by a Robust Radiofrequency Integrated Passive Device Biosensor Chip

    Science.gov (United States)

    Kim, Nam-Young; Adhikari, Kishor Kumar; Dhakal, Rajendra; Chuluunbaatar, Zorigt; Wang, Cong; Kim, Eun-Soo

    2015-01-01

    Tremendous demands for sensitive and reliable label-free biosensors have stimulated intensive research into developing miniaturized radiofrequency resonators for a wide range of biomedical applications. Here, we report the development of a robust, reusable radiofrequency resonator based integrated passive device biosensor chip fabricated on a gallium arsenide substrate for the detection of glucose in water-glucose solutions and sera. As a result of the highly concentrated electromagnetic energy between the two divisions of an intertwined spiral inductor coupled with an interdigital capacitor, the proposed glucose biosensor chip exhibits linear detection ranges with high sensitivity at center frequency. This biosensor, which has a sensitivity of up to 199 MHz/mgmL−1 and a short response time of less than 2 sec, exhibited an ultralow detection limit of 0.033 μM and a reproducibility of 0.61% relative standard deviation. In addition, the quantities derived from the measured S-parameters, such as the propagation constant (γ), impedance (Z), resistance (R), inductance (L), conductance (G) and capacitance (C), enabled the effective multi-dimensional detection of glucose. PMID:25588958

  14. Radiofrequency and microwave tumor ablation in patients with implanted cardiac devices: Is it safe?

    Energy Technology Data Exchange (ETDEWEB)

    Skonieczki, Brendan D., E-mail: bskonieczki@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Wells, Catherine, E-mail: cwells1@bidmc.harvard.edu [Department of Radiology, Harvard Medical School/Beth Israel Deaconess Medical Center, 330 Brookline Avenue, Boston, MA 02215 (United States); Wasser, Elliot J., E-mail: ewasser@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States); Dupuy, Damian E., E-mail: ddupuy@lifespan.org [Department of Diagnostic Imaging, Warren Alpert Medical School of Brown University/Rhode Island Hospital, 593 Eddy Street, Providence, RI 02903 (United States)

    2011-09-15

    Purpose: To identify malfunction of implanted cardiac devices during or after thermal ablation of tumors in lung, kidney, liver or bone, using radiofrequency (RF) or microwave (MW) energy. Materials and methods: After providing written consent, 19 patients (15 men and 4 women; mean age 78 years) with pacemakers or pacemaker/defibrillators underwent 22 CT image-guided percutaneous RF or MW ablation of a variety of tumors. Before and after each procedure, cardiac devices were interrogated and reprogrammed by a trained cardiac electrophysiology fellow. Possible pacer malfunctions included abnormalities on electrocardiographic (EKG) monitoring and alterations in device settings. Our institutional review board approved this Health Insurance Portability and Accountability Act-compliant study. Informed consent for participation in this retrospective study was deemed unnecessary by our review board. Results: During 20 of 22 sessions, no abnormalities were identified in continuous, EKG tracings or pacemaker functions. However, in two sessions significant changes, occurred in pacemaker parameters: inhibition of pacing during RF application in one, session and resetting of mode by RF energy in another session. These changes did not, result in hemodynamic instability of either patient. MW ablation was not associated with, any malfunction. In all 22 sessions, pacemakers were undamaged and successfully reset to original parameters. Conclusion: RF or MW ablation of tumors in liver, kidney, bone and lung can be performed safely in patients with permanent intra-cardiac devices, but careful planning between radiology and cardiology is essential to avoid adverse outcomes.

  15. Iron Oxide Nanoparticle-Based Magnetic Ink Development for Fully Printed Tunable Radio-Frequency Devices

    KAUST Repository

    Vaseem, Mohammad

    2018-01-30

    The field of printed electronics is still in its infancy and most of the reported work is based on commercially available nanoparticle-based metallic inks. Although fully printed devices that employ dielectric/semiconductor inks have recently been reported, there is a dearth of functional inks that can demonstrate controllable devices. The lack of availability of functional inks is a barrier to the widespread use of fully printed devices. For radio-frequency electronics, magnetic materials have many uses in reconfigurable components but rely on expensive and rigid ferrite materials. A suitable magnetic ink can facilitate the realization of fully printed, magnetically controlled, tunable devices. This report presents the development of an iron oxide nanoparticle-based magnetic ink. First, a tunable inductor is fully printed using iron oxide nanoparticle-based magnetic ink. Furthermore, iron oxide nanoparticles are functionalized with oleic acid to make them compatible with a UV-curable SU8 solution. Functionalized iron oxide nanoparticles are successfully embedded in the SU8 matrix to make a magnetic substrate. The as-fabricated substrate is characterized for its magnetostatic and microwave properties. A frequency tunable printed patch antenna is demonstrated using the magnetic and in-house silver-organo-complex inks. This is a step toward low-cost, fully printed, controllable electronic components.

  16. Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations.

    Science.gov (United States)

    Paknahad, Maryam; Mortazavi, S M J; Shahidi, Shoaleh; Mortazavi, Ghazal; Haghani, Masoud

    2016-01-01

    Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations. Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups. The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009). Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

  17. Electronic bipolar resistive switching behavior in Ni/VOx/Al device

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Mengseng [School of Electronic Information Engineering, Hebei University of Technology, Tianjin Key Laboratory of Electronic Materials and Devices, Tianjin 300130 (China); School of Electronic Information Engineering, Tianjin Key Laboratory of Film Electronic & Communication Devices, Tianjin University of Technology, Tianjin 300384 (China); Zhang, Kailiang, E-mail: kailiang_zhang@163.com [School of Electronic Information Engineering, Tianjin Key Laboratory of Film Electronic & Communication Devices, Tianjin University of Technology, Tianjin 300384 (China); Yang, Ruixia, E-mail: yangrx@hebut.edu.cn [School of Electronic Information Engineering, Hebei University of Technology, Tianjin Key Laboratory of Electronic Materials and Devices, Tianjin 300130 (China); Wang, Fang; Zhang, Zhichao; Wu, Shijian [School of Electronic Information Engineering, Tianjin Key Laboratory of Film Electronic & Communication Devices, Tianjin University of Technology, Tianjin 300384 (China)

    2017-07-15

    Highlights: • The resistive random access memory of Ni/VOx/Al was fabricated. • The device has the electronic bipolar resistive switching characteristic. • The activity energy (Ea) of HRS has been calculated. • The reasons of the degradation of the resistance ratio of HRS/LRS were analyzed. - Abstract: In this paper, the Ni/VOx/Al resistive random access memory (RRAM) device is constructed and it shows bipolar resistive switching behavior, low resistive state (LRS) nonlinearity, and good retention. The set and reset processes are likely induced by the electron trapping and detrapping of trapping centers in the VOx films, respectively. The conduction mechanism in negative/positive region are controlled by space charge limited current mechanism (SCLC)/Schottky emission. The temperature dependence of I–V curves for HRS is measured to confirm the defects trapping and detrapping electrons model. activation energy was calculated to analyze the endurance performance of the device. The detailed analysis of the switching behavior with SCLC mechanism and Schottky emission mechanism could provide useful information for electronic bipolar resistive switching (eBRS) characteristics.

  18. Electronic bipolar resistive switching behavior in Ni/VOx/Al device

    International Nuclear Information System (INIS)

    Xia, Mengseng; Zhang, Kailiang; Yang, Ruixia; Wang, Fang; Zhang, Zhichao; Wu, Shijian

    2017-01-01

    Highlights: • The resistive random access memory of Ni/VOx/Al was fabricated. • The device has the electronic bipolar resistive switching characteristic. • The activity energy (Ea) of HRS has been calculated. • The reasons of the degradation of the resistance ratio of HRS/LRS were analyzed. - Abstract: In this paper, the Ni/VOx/Al resistive random access memory (RRAM) device is constructed and it shows bipolar resistive switching behavior, low resistive state (LRS) nonlinearity, and good retention. The set and reset processes are likely induced by the electron trapping and detrapping of trapping centers in the VOx films, respectively. The conduction mechanism in negative/positive region are controlled by space charge limited current mechanism (SCLC)/Schottky emission. The temperature dependence of I–V curves for HRS is measured to confirm the defects trapping and detrapping electrons model. activation energy was calculated to analyze the endurance performance of the device. The detailed analysis of the switching behavior with SCLC mechanism and Schottky emission mechanism could provide useful information for electronic bipolar resistive switching (eBRS) characteristics.

  19. Bipolar resistive switching in room temperature grown disordered vanadium oxide thin-film devices

    Science.gov (United States)

    Wong, Franklin J.; Sriram, Tirunelveli S.; Smith, Brian R.; Ramanathan, Shriram

    2013-09-01

    We demonstrate bipolar switching with high OFF/ON resistance ratios (>104) in Pt/vanadium oxide/Cu structures deposited entirely at room temperature. The SET (RESET) process occurs when negative (positive) bias is applied to the top Cu electrode. The vanadium oxide (VOx) films are amorphous and close to the vanadium pentoxide stoichiometry. We also investigated Cu/VOx/W structures, reversing the position of the Cu electrode, and found the same polarity dependence with respect to the top and bottom electrodes, which suggests that the bipolar nature is linked to the VOx layer itself. Bipolar switching can be observed at 100 °C, indicating that it not due to a temperature-induced metal-insulator transition of a vanadium dioxide second phase. We discuss how ionic drift can lead to the bipolar electrical behavior of our junctions, similar to those observed in devices based on several other defective oxides. Such low-temperature processed oxide switches could be of relevance to back-end or package integration processing schemes.

  20. Home-based wrinkle reduction using a novel handheld multisource phase-controlled radiofrequency device.

    Science.gov (United States)

    Shemer, Avner; Levy, Hanna; Sadick, Neil S; Harth, Yoram; Dorizas, Andrew S

    2014-11-01

    In the last decade, energy-based aesthetic treatments, using light, radiofrequency (RF), and ultrasound, have gained scientific acceptance as safe and efficacious for non-invasive treatment for aesthetic skin disorders. The phase-controlled multisource radiofrequency technology (3DEEP™), which is based on the simultaneous use of multiple RF generators, was proven to allow significant pigment-independent dermal heating without pain or the need of epidermal cooling. This study was performed in order to evaluate the efficacy and safety of a new handheld device delivering multisource radiofrequency to the skin for wrinkle reduction and skin tightening in the home setting. A total of 69 participants (age 54.3 years ± 8.09; age range 37-72 years) were enrolled in the study after meeting all inclusion/exclusion criteria (100%) and providing informed consent. Participants were provided with the tested device together with a user manual and treatment diary, to perform independent treatments at home for 4 weeks. The tested device, (Newa™, EndyMed Medical, Cesarea, Israel) emits 12 W of 1Mhz, RF energy through six electrodes arranged in a linear fashion. Independent control of RF polarity through each one of the 6 electrodes allows significant reduction of energy flow through the epidermis with increased dermal penetration. Participants were instructed to perform at least 5 treatments a week, for one month. Four follow-up visits were scheduled (once a week) during the period of independent treatments at home, following 4 weeks of home treatments, 1 month follow-up visit (1 month after treatment end) and at 3 months follow-up (3 months following treatment end). Analysis of pre-and post treatment images was conducted by three uninvolved physicians experienced with the Fitzpatrick Wrinkle and Elastosis Scale. Fitzpatrick Wrinkle and Elastosis score of each time point (4 weeks following home use treatments; 1 month follow-up, 3 months follow-up) was compared to baseline

  1. Combination acetabular radiofrequency ablation and cementoplasty using a navigational radiofrequency ablation device and ultrahigh viscosity cement: technical note.

    Science.gov (United States)

    Wallace, Adam N; Huang, Ambrose J; Vaswani, Devin; Chang, Randy O; Jennings, Jack W

    2016-03-01

    Percutaneous radiofrequency ablation and cementoplasty is an alternative palliative therapy for painful metastases involving axial load-bearing bones. This technical report describes the use of a navigational radiofrequency probe to ablate acetabular metastases from an anterior approach followed by instillation of ultrahigh viscosity cement under CT-fluoroscopic guidance. The tumor ablation databases of two institutions were retrospectively reviewed to identify patients who underwent combination acetabular radiofrequency ablation and cementoplasty using the STAR Tumor Ablation and StabiliT Vertebral Augmentation Systems (DFINE; San Jose, CA). Pre-procedure acetabular tumor volume was measured on cross-sectional imaging. Pre- and post-procedure pain scores were measured using the Numeric Rating Scale (10-point scale) and compared. Partial pain improvement was categorically defined as ≥ 2-point pain score reduction. Patients were evaluated for evidence of immediate complications. Electronic medical records were reviewed for evidence of delayed complications. During the study period, 12 patients with acetabular metastases were treated. The median tumor volume was 54.3 mL (range, 28.3-109.8 mL). Pre- and post-procedure pain scores were obtained from 92% (11/12) of the cohort. The median pre-procedure pain score was 8 (range, 3-10). Post-procedure pain scores were obtained 7 days (82%; 9/11), 11 days (9.1%; 1/11) or 21 days (9.1%; 1/11) after treatment. The median post-treatment pain score was 3 (range, 1-8), a statistically significant difference compared with pre-treatment (P = 0.002). Categorically, 73% (8/11) of patients reported partial pain relief after treatment. No immediate symptomatic complications occurred. Three patients (25%; 3/12) were discharged to hospice within 1 week of treatment. No delayed complications occurred in the remaining 75% (9/12) of patients during median clinical follow-up of 62 days (range, 14-178 days). Palliative percutaneous

  2. Flexible Gallium Nitride for High-Performance, Strainable Radio-Frequency Devices.

    Science.gov (United States)

    Glavin, Nicholas R; Chabak, Kelson D; Heller, Eric R; Moore, Elizabeth A; Prusnick, Timothy A; Maruyama, Benji; Walker, Dennis E; Dorsey, Donald L; Paduano, Qing; Snure, Michael

    2017-12-01

    Flexible gallium nitride (GaN) thin films can enable future strainable and conformal devices for transmission of radio-frequency (RF) signals over large distances for more efficient wireless communication. For the first time, strainable high-frequency RF GaN devices are demonstrated, whose exceptional performance is enabled by epitaxial growth on 2D boron nitride for chemical-free transfer to a soft, flexible substrate. The AlGaN/GaN heterostructures transferred to flexible substrates are uniaxially strained up to 0.85% and reveal near state-of-the-art values for electrical performance, with electron mobility exceeding 2000 cm 2 V -1 s -1 and sheet carrier density above 1.07 × 10 13 cm -2 . The influence of strain on the RF performance of flexible GaN high-electron-mobility transistor (HEMT) devices is evaluated, demonstrating cutoff frequencies and maximum oscillation frequencies greater than 42 and 74 GHz, respectively, at up to 0.43% strain, representing a significant advancement toward conformal, highly integrated electronic materials for RF applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. A Preliminary Study of a Transdermal Radiofrequency Device for Body Slimming.

    Science.gov (United States)

    Key, Douglas J

    2015-11-01

    The use and potential of radiofrequency energy for tissue contracture and body contouring has been established in the literature. Maximum reduction of laxity can be achieved by simultaneously tightening surface tissue and reducing unwanted fat below by the transdermal application of heat to reach and maintain tissue temperature targets within a well-defined range, inducing collagen remodeling in skin as well as apoptosis of fat cells and creating an overall slimming effect. A novel device utilizes transcutaneous monopolar RF for body slimming in this manner, employing a thermistor feedback control mechanism to safely manage energy delivery and tissue temperature. Subjects (n=14) presenting with abdominal laxity were treated up to four times using the transcutaneous monopolar RF device at one or two zones in the abdominal region (at operator's discretion). Non-expert blinded graders rated correction on an arbitrary scale (0=no laxity, 4=maximum laxity) after choosing the order of the before-and-after photo sets. A patient satisfaction survey was also administered. The two graders correctly ordered 10 of 14 photo sets in agreement. Average rated improvement was 0.75 and 0.80 for graders 1 and 2, respectively. Patient survey results revealed average perceived tightening of 2.14 points on a 0 to 4 scale (0=lowest tightening result, 4=highest tightening), and 8 of 14 subjects would recommend treatment to others. Transdermal monopolar RF is a safe and effective modality for non-invasive body slimming.

  4. Endoscopic removal of over-the-scope clips: Clinical experience with a bipolar cutting device

    Science.gov (United States)

    Meier, Benjamin; Caca, Karel; Schmidt, Arthur

    2016-01-01

    Background Over-the-scope clips (OTSCs) are increasingly used for the closure of perforations/fistulae, hemostasis and endoscopic full-thickness resection (FTRD system). When OTSC-associated complications occur or re-therapy at the OTSC site is needed, OTSC removal may be indicated. An experimental study in an animal model and a case series have shown good results for OTSC removal with a bipolar cutting device. We present a larger clinical study using this device. Methods Data of all consecutive patients with indication for OTSC removal were collected and analyzed retrospectively. OTSCs were cut at two opposing sites using a bipolar grasping device to apply short direct current impulses. OTSC fragments were extracted with a standard forceps and a cap at the tip of the endoscope to avoid tissue damage. Results Between December 2012 and February 2016 a total of 42 OTSC removals in the upper (n = 25) and lower (n = 17) gastrointestinal tract have been performed at our department. Overall technical success, defined as cutting the OTSC at two opposing sites and extraction of both fragments, was achieved in 92.9% (39/42) of all cases. Successful fragmentation of the OTSC was achieved in 97.6% (41/42). Minor bleedings were rare and could be managed endoscopically in all cases. There were no perforations and no major or delayed bleedings. Conclusion Endoscopic OTSC removal with a bipolar cutting device is feasible, effective and safe. This technique can be applied in the upper and lower gastrointestinal tract. PMID:28588877

  5. High temperature radio-frequency superconducting quantum interference device system for detection of magnetic nanoparticles

    International Nuclear Information System (INIS)

    Pretzell, Alf

    2012-01-01

    This doctoral thesis was aimed at establishing a set-up with high-temperature superconductor (HTS) radio-frequency (rf) superconducting quantum interference device (SQUID) technology for the detection of magnetic nanoparticles and in particular for testing applications of magnetic nanoparticle immunoassays. It was part of the EU-project ''Biodiagnostics'' running from 2005 to 2008. The method of magnetic binding assays was developed as an alternative to other methods of concentration determination like enzyme linked immunosorbent assay (ELISA), or fluorescent immunoassay. The ELISA has sensitivities down to analyte-concentrations of pg/ml. Multiple incubation and washing steps have to be performed for these techniques, the analyte has to diffuse to the site of binding. The magnetic assay uses magnetic nanoparticles as markers for the substance to be detected. It is being explored by current research and shows similar sensitivity compared to ELISA but in contrast - does not need any washing and can be read out directly after binding - can be applied in solution with opaque media, e.g. blood or muddy water - additionally allows magnetic separation or concentration - in combination with small magnetoresistive or Hall sensors, allows detection of only a few particles or even single beads. For medical or environmental samples, maybe opaque and containing a multitude of substances, it would be advantageous to devise an instrument, which allows to be read out quickly and with high sensitivity. Due to the mentioned items the magnetic assay might be a possibility here.

  6. Development of corrosion condition sensing and monitoring system using radio-frequency identification devices (RFID)

    Energy Technology Data Exchange (ETDEWEB)

    Gu, G.P.; Zheng, W. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2008-05-15

    This study discussed the development of a corrosion sensing and monitoring system for military land vehicles. Radio-frequency identification device (RFID) technology uses radio waves to identify individual masses with RFID tags attached. A corrosion-sensing element was integrated with the RFID technology, which incorporated a galvanic corrosion cell designed to trigger RFID tags. Corrosion severity was then related to the galvanic current. The tag recorded the sensor reading and transmitted the data to an RFID reader. The tags consisted of a microchip and an antenna. A software development kit has also been developed to interface RFID data with existing applications. While it is currently not possible to modify the RFID tags to prevent security risks, further research is being conducted to assemble a data-logger system with corrosion probes to measure humidity, electrical resistance, and linear polarization resistance. Studies will also be conducted to assemble an active tag reader system and investigate potential modifications. 4 refs., 1 fig., 1 appendix.

  7. The fitting parameters extraction of conversion model of the low dose rate effect in bipolar devices

    International Nuclear Information System (INIS)

    Bakerenkov, Alexander

    2011-01-01

    The Enhanced Low Dose Rate Sensitivity (ELDRS) in bipolar devices consists of in base current degradation of NPN and PNP transistors increase as the dose rate is decreased. As a result of almost 20-year studying, the some physical models of effect are developed, being described in detail. Accelerated test methods, based on these models use in standards. The conversion model of the effect, that allows to describe the inverse S-shaped excess base current dependence versus dose rate, was proposed. This paper presents the problem of conversion model fitting parameters extraction.

  8. A comparison of microwave ablation and bipolar radiofrequency ablation both with an internally cooled probe: Results in ex vivo and in vivo porcine livers

    International Nuclear Information System (INIS)

    Yu Jie; Liang Ping; Yu Xiaoling; Liu Fangyi; Chen Lei; Wang Yang

    2011-01-01

    Purpose: The purpose of this study was to compare the effectiveness of microwave (MW) ablation and radiofrequency (RF) ablation using a single internally cooled probe in a hepatic porcine model. Materials and methods: In the ex vivo experiment, MW ablations (n = 40) were performed with a 2450 MHz and 915 MHz needle antenna, respectively at 60 W, 70 W power settings. Bipolar RF ablations (n = 20) were performed with a 3-cm (T30) and 4-cm (T40) active tip needle electrodes, respectively at a rated power 30 W and 40 W according to automatically systematic power setting. In the in vivo experiment, the 2450 MHz and 915 MHz MW ablation both at 60 W and T30 bipolar RF ablation at 30 W were performed (n = 30). All of the application time were 10 min. Long-axis diameter (Dl), short-axis diameter (Ds), ratio of Ds/Dl, the temperature data 5 mm from the needle and the time of temperature 5 mm from the needle rising to 54 deg. C were measured. Results: Both in ex vivo and in vivo models, Ds and Dl of 915 MHz MW ablations were significantly larger than all the RF ablations (P < 0.05); the Ds for all the 2450 MHz MW ablations were significantly larger than that of T30 RF ablations (P < 0.05). 2450 MHz MW and T30 RF ablation tended to produce more elliptical-shaped ablation zone. Tissue temperatures 5 mm from the needle were considerably higher with MW ablation, meanwhile MW ablation achieved significantly faster rate of temperature rising to 54 deg. C than RF ablation. For in vivo study after 10 min of ablation, the Ds and Dl of 2450 MHz MW, 915 MHz MW and Bipolar RF were 2.35 ± 0.75, 2.95 ± 0.32, 1.61 ± 0.33 and 3.86 ± 0.81, 5.79 ± 1.03, 3.21 ± 0.51, respectively. Highest tissue temperatures 5 mm from the needle were 80.07 ± 12.82 deg. C, 89.07 ± 3.52 deg. C and 65.56 ± 15.31 deg. C and the time of temperature rising to 54 deg. C were respectively 37.50 ± 7.62 s, 24.50 ± 4.09 s and 57.29 ± 23.24 s for three applicators. Conclusion: MW ablation may have higher

  9. Treatment of facial skin laxity by a new monopolar radiofrequency device

    Directory of Open Access Journals (Sweden)

    Uwe Wollina

    2011-01-01

    Full Text Available Background : Acquired facial skin laxity seems to be a result of the combination of intrinsic and extrinsic processes. For treatment of facial ageing, non-invasive procedures have become popular. Aim : We wanted to investigate the effect of a new 2.2-MHz radiofrequency (RF device on acquired facial skin laxity. Setting : Outpatient clinic associated with an academic teaching hospital. Materials and Methods : We performed an open trial with the RF-ReFacing™ device (Meyer-Haake Medical Innovations, Wehrheim/ Germany in the monopolar mode with a power of 8-12 W, two passes per session and repetition three times after 2 weeks without treatment. Results : A total of 20 Caucasian female patients were included (age range, 34-73 years. The procedure was performed without any analgesia. We did not see any adverse effect. The procedure was scored as most convenient or convenient by all patients. Improvement in skin laxity and fine wrinkles was seen after the second treatment in 19 of the 20 patients and after the third treatment in 100% of the patients. On a scale from 0 to 3, improvement in the lower lid, Crow′s feet and jowl line was scored 2.6±0.7 by the patients; improvement in the overall appearance of the face was scored 2.3±0.5. Blinded assessment of the photographs rated the improvement as good or better in 15 of the 20 patients, moderate in 3 patients, no change in 1 patient. Conclusions : RF-ReFacing™ treatment was effective in improvement in skin laxity. Patients′ satisfaction was high. Although RF-ReFacing™ treatment cannot substitute surgical procedure, it might prolong the time to the first surgical facial lift. The number of patients treated was small, and no quantitative measurements or histopathology was performed. Hence further studies with greater number of patients are necessary.

  10. Influence of the Dermis Thickness on the Results of the Skin Treatment with Monopolar and Bipolar Radiofrequency Currents.

    Science.gov (United States)

    Kruglikov, Ilja L

    2016-01-01

    Electrically layered tissue structure significantly modifies distribution of radiofrequency (RF) current in the dermis and in the subcutaneous adipose tissue comparing to that in a homogeneous medium. On the basis of the simple model of RF current distribution in a two-layer skin containing dermis and subcutis, we assess the influence of the dermal thickness on the current density in different skin layers. Under other equal conditions, current density in the dermis is higher for the skin having thinner dermis. This contradicts the main paradigm of the RF theory stating that treatment results are mainly dependent on the maximal temperature reached in a target tissue, since the best short- and long-term clinical results of RF application to the skin were reported in the areas having thicker dermis. To resolve this contradiction, it is proposed that the long-term effect of RF can be realized through a structural modification of the subcutaneous fat depot adjacent to the treated skin area. Stimulation of these cells located near the interface dermis/subcutis will demand the concentration of applied RF energy in this area and will require the optimal arrangement of RF electrodes on the skin surface.

  11. Influence of the Dermis Thickness on the Results of the Skin Treatment with Monopolar and Bipolar Radiofrequency Currents

    Directory of Open Access Journals (Sweden)

    Ilja L. Kruglikov

    2016-01-01

    Full Text Available Electrically layered tissue structure significantly modifies distribution of radiofrequency (RF current in the dermis and in the subcutaneous adipose tissue comparing to that in a homogeneous medium. On the basis of the simple model of RF current distribution in a two-layer skin containing dermis and subcutis, we assess the influence of the dermal thickness on the current density in different skin layers. Under other equal conditions, current density in the dermis is higher for the skin having thinner dermis. This contradicts the main paradigm of the RF theory stating that treatment results are mainly dependent on the maximal temperature reached in a target tissue, since the best short- and long-term clinical results of RF application to the skin were reported in the areas having thicker dermis. To resolve this contradiction, it is proposed that the long-term effect of RF can be realized through a structural modification of the subcutaneous fat depot adjacent to the treated skin area. Stimulation of these cells located near the interface dermis/subcutis will demand the concentration of applied RF energy in this area and will require the optimal arrangement of RF electrodes on the skin surface.

  12. Characterization of four different bipolar charging devices for nanoparticle charge conditioning

    International Nuclear Information System (INIS)

    Kallinger, Peter; Steiner, Gerhard; Szymanski, Wladyslaw W.

    2012-01-01

    Well-defined charge conditioning of nanoparticles is a prerequisite for a number of particle measuring techniques. We investigated two different soft X-ray devices (custom-built and TSI advanced aerosol neutralizer) an AC-corona discharge device (MSP electrical ionizer) and a radioactivity based Am-241 charger as a reference. Electrical mobility size distributions of positive and negative ions created in all devices were determined and their applicability for particle charging examined. The mobility spectra of the positive ions were found to be quite comparable for all chargers with a mean mobility of 1.50–1.60 cm 2 V −1 s −1 , whereas the spectra of the negative ions show differences in morphology leading to a broader range of mean mobilities (1.68–2.09 cm 2 V −1 s −1 ). However, results confirm that under the selected experimental conditions the charge equilibrium related to bipolar diffusion charging process was obtained in all charging devices.

  13. A proposed hardness assurance test methodology for bipolar linear circuits and devices in a space ionizing radiation environment

    International Nuclear Information System (INIS)

    Pease, R.L.; Brown, D.B.; Cohn, L.

    1997-01-01

    A hardness assurance test approach has been developed for bipolar linear circuits and devices in space. It consists of a screen for dose rate sensitivity and a characterization test method to develop the conditions for a lot acceptance test at high dose rate

  14. Graphene screen-printed radio-frequency identification devices on flexible substrates

    NARCIS (Netherlands)

    Arapov, K.; Jaakkola, K.; Ermolov, V.; Bex, G.; Rubingh, E.; Haque, S.; Sandberg, H.; Abbel, R.; de With, G.; Friedrich, H.

    2016-01-01

    Despite the great promise of printed flexible electronics from 2D crystals, and especially graphene, few scalable applications have been reported so far that can be termed roll-to-roll compatible. Here we combine screen printed graphene with photonic annealing to realize radio-frequency

  15. The efficacy of a combination non-thermal focused ultrasound and radiofrequency device for noninvasive body contouring in Asians.

    Science.gov (United States)

    Shek, Samantha Y N; Yeung, Chi K; Chan, Johnny C Y; Chan, Henry H L

    2016-02-01

    Several studies have been published on the first generation non-thermal focused ultrasound with an average improvement of 0-3.95 cm reported. We aim to investigate the efficacy of the second-generation non-thermal focused ultrasound device with a combined radiofrequency hand piece. With the addition of radiofrequency energy, the temperature of the adipose tissue is raised before focused ultrasound is applied. This facilitates the mechanical disruption of fat cells by focused ultrasound. Twenty subjects were recruited and underwent three treatments biweekly. Caliper reading, abdominal circumference, and standardized photographs were taken with the Vectra(®) system at all visits. We aim to have the subjects stand and hold the same position and the photograph taken after exhalation. Caliper and circumference measurements carry uncertainty. It is impossible to eliminate all uncertainties but can be improved by having the same trained physician assistant perform the measurement at the same site and taking an average of three readings. Pain score and satisfaction were recorded by means of the visual analogue scale. The efficacy is defined by a statistically significant improvement in circumferential improvement based on intention-to-treat analysis. Seventeen subjects completed the treatment schedule. Abdominal circumference showed statistically significant improvement at 2 weeks post-second treatment (P = 0.023) and almost all subsequent follow-ups. Caliper readings were statistically significant at 2 weeks post-second treatment (P = 0.013) and almost all follow-ups. The mean pain score reported was 2.3 on the visual analog scale and 6% were unsatisfied with the overall treatments. Six incidents of wheal formation appeared immediately after treatment all of which subsided spontaneously within several hours. The combination non-thermal focused ultrasound and radiofrequency device is effective for improving body contour in Asians. © 2015 Wiley Periodicals, Inc.

  16. MicroElectroMechanical devices and fabrication technologies for radio-frequency analog signal processing

    Science.gov (United States)

    Young, Darrin Jun

    The proliferation of wireless services creates a pressing need for compact and low cost RF transceivers. Modern sub-micron technologies provide the active components needed for miniaturization but fail to deliver high quality passives needed in oscillators and filters. This dissertation demonstrates procedures for adding high quality inductors and tunable capacitors to a standard silicon integrated circuits. Several voltage-controlled oscillators operating in the low Giga-Hertz range demonstrate the suitability of these components for high performance RF building blocks. Two low-temperature processes are described to add inductors and capacitors to silicon ICs. A 3-D coil geometry is used for the inductors rather than the conventional planar spiral to substantially reduce substrate loss and hence improve the quality factor and self-resonant frequency. Measured Q-factors at 1 GHz are 30 for a 4.8 nH device, 16 for 8.2 nH and 13.8 nH inductors. Several enhancements are proposed that are expected to result in a further improvement of the achievable Q-factor. This research investigates the design and fabrication of silicon-based IC-compatible high-Q tunable capacitors and inductors. The goal of this investigation is to develop a monolithic low phase noise radio-frequency voltage-controlled oscillator using these high-performance passive components for wireless communication applications. Monolithic VCOs will help the miniaturization of current radio transceivers, which offers a potential solution to achieve a single hand-held wireless phone with multistandard capabilities. IC-compatible micromachining fabrication technologies have been developed to realize on-chip high-Q RF tunable capacitors and 3-D coil inductors. The capacitors achieve a nominal capacitance value of 2 pF and can be tuned over 15% with 3 V. A quality factor over 60 has been measured at 1 GHz. 3-D coil inductors obtain values of 4.8 nH, 8.2 nH and 13.8 nH. At 1 GHz a Q factor of 30 has been achieved

  17. Feasibility study of using a Zener diode as the selection device for bipolar RRAM and WORM memory arrays

    International Nuclear Information System (INIS)

    Li, Yingtao; Fu, Liping; Tao, Chunlan; Jiang, Xinyu; Sun, Pengxiao

    2014-01-01

    Cross-bar arrays are usually used for the high density application of resistive random access memory (RRAM) devices. However, cross-talk interference limits an increase in the integration density. In this paper, the Zener diode is proposed as a selection device to suppress the sneak current in bipolar RRAM arrays. Measurement results show that the Zener diode can act as a good selection device, and the sneak current can be effectively suppressed. The readout margin is sufficiently improved compared to that obtained without the selection device. Due to the improvement for the reading disturbance, the size of the cross-bar array can be enhanced to more than 10 3  × 10 3 . Furthermore, the possibility of using a write-once-read-many-times (WORM) cross-bar array is also demonstrated by connecting the Zener diode and the bipolar RRAM in series. These results strongly suggest that using a Zener diode as a selection device opens up great opportunities to realize high density bipolar RRAM arrays. (paper)

  18. Development of corrosion condition sensing and monitoring system using radio-frequency identification devices (RFID) : progress report 2

    Energy Technology Data Exchange (ETDEWEB)

    Gu, G.P.; Li, J.; Liu, P.; Bibby, D.; Zheng, W.; Lo, J. [Natural Resources Canada, Ottawa, ON (Canada). CANMET Materials Technology Laboratory

    2008-12-15

    The development of a corrosion severity monitoring system that used radio-frequency identification device (RIFD) technology was discussed. A corrosion monitoring sensor was integrated with a tag modified to partially block the radio frequency signal. The metallic coating caused a frequency shift of the device's reader antenna in order to allow for the accurate characterization of metal coatings. Communications between the tag and the reader were re-established as the corrosion process gradually deteriorated the coating. The method was tested experimentally with 3 RFID systems using both active and passive tags were assembled. A passive tag was covered in aluminum foil. Results of the experiment showed that the metallic coating interfered with RFID signals. A cold-spray technology was used to coat tags with metal alloys. The surface morphology of the coatings was tested to determine optimum coating parameters. Further studies are being conducted to develop software for the technology. 4 refs., 11 figs.

  19. Bipolar sealer device reduces blood loss and transfusion requirements in posterior spinal fusion for adolescent idiopathic scoliosis.

    Science.gov (United States)

    Gordon, Zachary L; Son-Hing, Jochen P; Poe-Kochert, Connie; Thompson, George H

    2013-01-01

    Reducing perioperative blood loss and transfusion requirements is important in the operative treatment of idiopathic scoliosis. This can be achieved with special frames, cell saver systems, pharmacologic aspects, and other techniques. Recently there has been interest in bipolar sealer devices as an adjunct to traditional monopolar electrocautery. However, there is limited information on this device in pediatric spinal deformity surgery. We reviewed our experience with this device in a setting of a standard institutional operative carepath. Perioperative blood loss and transfusion requirements of 50 consecutive patients with adolescent idiopathic scoliosis undergoing a posterior spinal fusion and segmental spinal instrumentation and who had a bipolar sealer device used during their surgery was compared with a control group of the 50 preceding consecutive patients who did not. Anesthesia, surgical technique, use of intraoperative epsilon aminocaproic acid (Amicar), postoperative protocol, and indications for transfusions (hemoglobin≤7.0 g/dL) were identical in both groups. The preoperative demographics for the patients in both groups were statistically the same. The bipolar sealer group demonstrated a significant reduction in intraoperative estimated blood loss, total perioperative blood loss, volume of blood products transfused, and overall transfusion rate when compared with the control group. When subgroups consisting of only hybrid or all-pedicle screw constructs were considered individually, these findings remained consistent. There were no complications associated with the use of this device. Using the bipolar sealer device is a significant adjunct in decreasing perioperative blood loss and transfusion requirements in patients undergoing surgery for adolescent idiopathic scoliosis. Level III-retrospective comparative study.

  20. Design and construction of a resistive energy dump device for bipolar superconducting magnet systems

    Energy Technology Data Exchange (ETDEWEB)

    Mohan, M. J.

    1977-05-01

    When superconducting magnets quench, the resistance of the conductor material rises rapidly to its normal value. This increase in resistance can result in catastrophic heating in the magnet unless stored field energy is quickly removed from the system. Phase inversion is the normal mode of energy removal. SCR's in the power supply are phased back, the output of the supply is inverted, and magnetic field energy is directed back into the utility grid. Under certain conditions, however, the power supply may fail to invert properly, and an alternate energy removal scheme must protect the superconducting magnet system. Composed of an isolation switch, a semiconductor switching module, and a dump resistor, the resistive dump device provides a viable protection scheme. Operationally, several conditions are capable of activating the isolation switch and triggering the bipolar SCR switching module. Manual dump commands, for instance, permit the operator to dump field energy in the event of observed abnormalities. A special voltage tap quench detector senses the aforementioned abnormal power supply output inversion and also fires the dump circuit. Regardless of the nature of the trigger input, however, activation of the energy dump device diverts coil current through the dump resistor. I/sup 2/R losses over time then safely dissipate stored magnetic field energy.

  1. No-touch radiofrequency ablation using multiple electrodes: An in vivo comparison study of switching monopolar versus switching bipolar modes in porcine livers.

    Directory of Open Access Journals (Sweden)

    Won Chang

    Full Text Available To evaluate the in vivo technical feasibility, efficiency, and safety of switching bipolar (SB and switching monopolar (SM radiofrequency ablation (RFA as a no-touch ablation technique in the porcine liver.The animal care and use committee approved this animal study and 16 pigs were used in two independent experiments. In the first experiment, RFA was performed on 2-cm tumor mimickers in the liver using a no-touch technique in the SM mode (2 groups, SM1: 10 minutes, n = 10; SM2: 15 minutes, n = 10 and SB-mode (1 group, SB: 10 minutes, n = 10. The technical success with sufficient safety margins, creation of confluent necrosis, ablation size, and distance between the electrode and ablation zone margin (DEM, were compared between groups. In the second experiment, thermal injury to the adjacent anatomic organs was compared between SM-RFA (15 minutes, n = 13 and SB-RFA modes (10 minutes, n = 13.The rates of the technical success and the creation of confluent necrosis were higher in the SB group than in the SM1 groups (100% vs. 60% and 90% vs. 40%, both p < 0.05. The ablation volume in the SM2 group was significantly larger than that in the SB group (59.2±18.7 cm3 vs. 39.8±9.7 cm3, p < 0.05, and the DEM in the SM2 group was also larger than that in the SB group (1.39±0.21 cm vs. 1.07±0.10 cm, p < 0.05. In the second experiment, the incidence of thermal injury to the adjacent organs and tissues in the SB group (23.1%, 3/13 was significantly lower than that in the SM group (69.2%, 8/13 (p = 0.021.SB-RFA was more advantageous for a no-touch technique for liver tumors, showing the potential of a better safety profile than SM-RFA.

  2. The quest for durable lesions in catheter ablation of atrial fibrillation - technological advances in radiofrequency catheters and balloon devices.

    Science.gov (United States)

    Maurer, Tilman; Kuck, Karl-Heinz

    2017-08-01

    Atrial fibrillation is the most common cardiac arrhythmia and represents a growing clinical, social and economic challenge. Catheter ablation for symptomatic atrial fibrillation has evolved from an experimental procedure into a widespread therapy and offers a safe and effective treatment option. A prerequisite for durable PVI are transmural and contiguous circumferential lesions around the pulmonary veins. However, electrical reconnection of initially isolated pulmonary veins remains a primary concern and is a dominant factor for arrhythmia recurrence during long-term follow up. Areas covered: This article discusses the physiology of lesion formation using radiofrequency-, cryo- or laser- energy for pulmonary vein isolation and provides a detailed review of recent technological advancements in the field of radiofrequency catheters and balloon devices. Finally, future directions and upcoming developments for the interventional treatment of atrial fibrillation are discussed. Expert commentary: Durable conduction block across deployed myocardial lesions is mandatory not only for PVI but for any other cardiac ablation strategy as well. A major improvement urgently expected is the intraprocedural real-time distinction of durable lesions from interposed gaps with only transiently impaired electrical conduction. Furthermore, a simplification of ablation tools used for PVI is required to reduce the high technical complexity of the procedure.

  3. 21 CFR 882.4725 - Radiofrequency lesion probe.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion probe. 882.4725 Section 882...) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4725 Radiofrequency lesion probe. (a) Identification. A radiofrequency lesion probe is a device connected to a radiofrequency (RF...

  4. LAPAROSCOPICALLY ASSISTED ANORECTOPLASTY AND THE USE OF THE BIPOLAR DEVICE TO SEAL THE RECTAL URINARY FISTULA.

    Science.gov (United States)

    Dutra, Robson Azevedo; Boscollo, Adriana Cartafina Perez

    2016-01-01

    The anorectal anomalies consist in a complex group of birth defects. Laparoscopic-assisted anorectoplasty improved visualization of the rectal fistula and the ability to place the pull-through segment within the elevator muscle complex with minimal dissection. There is no consensus on how the fistula should be managed. To evaluate the laparoscopic-assisted anorectoplasty and the treatment of the rectal urinary fistula by a bipolar sealing device. It was performed according to the original description by Georgeson1. Was used 10 mm infraumbilical access portal for 30º optics. The pneumoperitoneum was established with pressure 8-10 cm H2O. Two additional trocars of 5 mm were placed on the right and left of the umbilicus. The dissection started on peritoneal reflection using Ligasure(r). With the reduction in the diameter of the distal rectum was identified the fistula to the urinary tract. The location of the new anus was defined by the location of the external anal sphincter muscle complex, using electro muscle stimulator externally. Finally, it was made an anastomosis between the rectum and the new location of the anus. A Foley urethral probe was left for seven days. Seven males were operated, six with rectoprostatic and one with rectovesical fistula. The follow-up period ranged from one to four years. The last two patients operated underwent bipolar sealing of the fistula between the rectum and urethra without sutures or surgical ligation. No evidence of urethral leaks was identified. There are benefits of the laparoscopic-assisted anorectoplasty for the treatment of anorectal anomaly. The use of a bipolar energy source that seals the rectal urinary fistula has provided a significant decrease in the operating time and made the procedure be more elegant. As anomalias anorretais consistem de um grupo complexo de defeitos congênitos. A anorretoplastia laparoscópica permite melhor visualização da fístula retourinária e propicia o posicionamento do reto abaixado

  5. Implanting inequality: empirical evidence of social and ethical risks of implantable radio-frequency identification (RFID) devices.

    Science.gov (United States)

    Monahan, Torin; Fisher, Jill A

    2010-10-01

    The aim of this study was to assess empirically the social and ethical risks associated with implantable radio-frequency identification (RFID) devices. Qualitative research included observational studies in twenty-three U.S. hospitals that have implemented new patient identification systems and eighty semi-structured interviews about the social and ethical implications of new patient identification systems, including RFID implants. The study identified three primary social and ethical risks associated with RFID implants: (i) unfair prioritization of patients based on their participation in the system, (ii) diminished trust of patients by care providers, and (iii) endangerment of patients who misunderstand the capabilities of the systems. RFID implants may aggravate inequalities in access to care without any clear health benefits. This research underscores the importance of critically evaluating new healthcare technologies from the perspective of both normative ethics and empirical ethics.

  6. Thermal Response of In Vivo Human Skin to Fractional Radiofrequency Microneedle Device

    Directory of Open Access Journals (Sweden)

    Woraphong Manuskiatti

    2016-01-01

    Full Text Available Background. Fractional radiofrequency microneedle system (FRMS is a novel fractional skin resurfacing system. Data on thermal response to this fractional resurfacing technique is limited. Objectives. To investigate histologic response of in vivo human skin to varying energy settings and pulse stacking of a FRMS in dark-skinned subjects. Methods. Two female volunteers who were scheduled for abdominoplasty received treatment with a FRMS with varying energy settings at 6 time periods including 3 months, 1 month, 1 week, 3 days, 1 day, and the time immediately before abdominoplasty. Biopsy specimens were analyzed using hematoxylin and eosin (H&E, Verhoeff-Van Gieson (VVG, colloidal iron, and Fontana-Masson stain. Immunohistochemical study was performed by using Heat Shock Protein 70 (HSP70 antibody and collagen III monoclonal antibody. Results. The average depth of radiofrequency thermal zone (RFTZ ranged from 100 to 300 μm, correlating with energy levels. Columns of cell necrosis and collagen denaturation followed by inflammatory response were initially demonstrated, with subsequent increasing of mucin at 1 and 3 months after treatment. Immunohistochemical study showed positive stain with HSP70. Conclusion. A single treatment with a FRMS using appropriate energy setting induces neocollagenesis. This wound healing response may serve as a mean to improve the appearance of photodamaged skin and atrophic scars.

  7. Radiofrequency Neurotomy

    Science.gov (United States)

    ... your specific symptoms. What you can expect Before radiofrequency neurotomy Let your doctor know if you take ... tobacco products the day of your procedure. During radiofrequency neurotomy Radiofrequency neurotomy is an outpatient procedure, so ...

  8. Effect of the Size of the Left Atrium on Sustained Sinus Rhythm in Patients Undergoing Mitral Valve Surgery and Concomitant Bipolar Radiofrequency Ablation for Atrial Fibrillation.

    Science.gov (United States)

    Avdagić, Harun; Sijerčić Avdagić, Selma; Pirić Avdagić, Melika; Antonič, Miha

    2017-12-01

    Atrial fibrillation is associated with systemic embolization and complications due to anticoagulant therapy. Radiofrequency ablation has been established as an effective and safe method for the treatment of atrial fibrillation. The aim of this study was to evaluate the effect of the size of the left atrium on the outcome of surgical radiofrequency ablation. Forty patients scheduled for elective mitral valve surgery and radiofrequency ablation were enrolled in the study. Group 1 consisted of patients with a left atrium diameter ≤5 cm and group 2 of patients with left atrium diameter >5 cm. The primary endpoint of the study was stable sinus rhythm 6 months postoperatively. At 6 months postoperatively, sinus rhythm was present in significantly more group 1 patients as compared with group 2 patients, i.e. 15 (75%) vs. 8 (40%), p=0.025. Multivariate analysis proved the size of the left atrium to be an independent predictor of the radiofrequency ablation outcome. Accordingly, the size of the left atrium was demonstrated to be an important predictor of the outcome of radiofrequency ablation for atrial fibrillation. A lower cut-off value of surgical reduction of the atria than previously reported should be considered in order to improve the radiofrequency ablation outcome.

  9. The bipolar silicon microstrip detector: A proposal for a novel precision tracking device

    International Nuclear Information System (INIS)

    Horisberger, R.

    1990-01-01

    It is proposed to combine the technology of fully depleted microstrip detectors fabricated on n doped high resistivity silicon with the concept of the bipolar transistor. This is done by adding a n ++ doped region inside the normal p + implanted region of the reverse biased p + n diode. The resulting structure has amplifying properties and is referred to as bipaolar pixel transistor. The simplest readout scheme of a bipolar pixel array by an aluminium strip bus leads to the bipolar microstrip detector. The bipolar pixel structure is expected to give a better signal-to-noise performance for the detection of minimum ionizing charged particle tracks than the normal silicon diode strip detector and therefore should allow in future the fabrication of thinner silicon detectors for precision tracking. (orig.)

  10. Modeling of transient ionizing radiation effects in bipolar devices at high dose-rates

    International Nuclear Information System (INIS)

    FJELDLY, T.A.; DENG, Y.; SHUR, M.S.; HJALMARSON, HAROLD P.; MUYSHONDT, ARNOLDO

    2000-01-01

    To optimally design circuits for operation at high intensities of ionizing radiation, and to accurately predict their a behavior under radiation, precise device models are needed that include both stationary and dynamic effects of such radiation. Depending on the type and intensity of the ionizing radiation, different degradation mechanisms, such as photoelectric effect, total dose effect, or single even upset might be dominant. In this paper, the authors consider the photoelectric effect associated with the generation of electron-hole pairs in the semiconductor. The effects of low radiation intensity on p-II diodes and bipolar junction transistors (BJTs) were described by low-injection theory in the classical paper by Wirth and Rogers. However, in BJTs compatible with modem integrated circuit technology, high-resistivity regions are often used to enhance device performance, either as a substrate or as an epitaxial layer such as the low-doped n-type collector region of the device. Using low-injection theory, the transient response of epitaxial BJTs was discussed by Florian et al., who mainly concentrated on the effects of the Hi-Lo (high doping - low doping) epilayer/substrate junction of the collector, and on geometrical effects of realistic devices. For devices with highly resistive regions, the assumption of low-level injection is often inappropriate, even at moderate radiation intensities, and a more complete theory for high-injection levels was needed. In the dynamic photocurrent model by Enlow and Alexander. p-n junctions exposed to high-intensity radiation were considered. In their work, the variation of the minority carrier lifetime with excess carrier density, and the effects of the ohmic electric field in the quasi-neutral (q-n) regions were included in a simplified manner. Later, Wunsch and Axness presented a more comprehensive model for the transient radiation response of p-n and p-i-n diode geometries. A stationary model for high-level injection in p

  11. Coexistence of unipolar and bipolar resistive switching behaviors in NiFe2O4 thin film devices by doping Ag nanoparticles

    Science.gov (United States)

    Hao, Aize; Ismail, Muhammad; He, Shuai; Huang, Wenhua; Qin, Ni; Bao, Dinghua

    2018-02-01

    The coexistence of unipolar and bipolar resistive switching (RS) behaviors of Ag-nanoparticles (Ag-NPs) doped NiFe2O4 (NFO) based memory devices was investigated. The switching voltages of required operations in the unipolar mode were smaller than those in the bipolar mode, while ON/OFF resistance levels of both modes were identical. Ag-NPs doped NFO based devices could switch between the unipolar and bipolar modes just by preferring the polarity of RESET voltage. Besides, the necessity of identical compliance current during the SET process of unipolar and bipolar modes provided an additional advantage of simplicity in device operation. Performance characteristics and cycle-to-cycle uniformity (>103 cycles) in unipolar operation were considerably better than those in bipolar mode (>102 cycles) at 25 °C. Moreover, good endurance (>600 cycles) at 200 °C was observed in unipolar mode and excellent nondestructive retention characteristics were obtained on memory cells at 125 °C and 200 °C. On the basis of temperature dependence of resistance at low resistance state, it was believed that physical origin of the RS mechanism involved the formation/rupture of the conducting paths consisting of oxygen vacancies and Ag atoms, considering Joule heating and electrochemical redox reaction effects for the unipolar and bipolar resistive switching behaviors. Our results demonstrate that 0.5% Ag-NPs doped nickel ferrites are promising resistive switching materials for resistive access memory applications.

  12. 78 FR 25916 - Authorization of Radiofrequency Equipment

    Science.gov (United States)

    2013-05-03

    ...] Authorization of Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Proposed rule... bodies, and measurement procedures used to determine RF equipment compliance. The Commission believes... Commission is responsible for an equipment authorization program for radiofrequency (RF) devices under part 2...

  13. Enhanced Field Emission Studies on Niobium Surfaces Relevant to High Field Superconducting Radio-Frequency Devices

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Tong [Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)

    2002-09-18

    Enhanced field emission (EFE) presents the main impediment to higher acceleration gradients in superconducting niobium (Nb) radiofrequency cavities for particle accelerators. The strength, number and sources of EFE sites strongly depend on surface preparation and handling. The main objective of this thesis project is to systematically investigate the sources of EFE from Nb, to evaluate the best available surface preparation techniques with respect to resulting field emission, and to establish an optimized process to minimize or eliminate EFE. To achieve these goals, a scanning field emission microscope (SFEM) was designed and built as an extension to an existing commercial scanning electron microscope (SEM). In the SFEM chamber of ultra high vacuum, a sample is moved laterally in a raster pattern under a high voltage anode tip for EFE detection and localization. The sample is then transferred under vacuum to the SEM chamber equipped with an energy-dispersive x-ray spectrometer for individual emitting site characterization. Compared to other systems built for similar purposes, this apparatus has low cost and maintenance, high operational flexibility, considerably bigger scan area, as well as reliable performance. EFE sources from planar Nb have been studied after various surface preparation, including chemical etching and electropolishing, combined with ultrasonic or high-pressure water rinse. Emitters have been identified, analyzed and the preparation process has been examined and improved based on EFE results. As a result, field-emission-free or near field-emission-free surfaces at ~140 MV/m have been consistently achieved with the above techniques. Characterization on the remaining emitters leads to the conclusion that no evidence of intrinsic emitters, i.e., no fundamental electric field limit induced by EFE, has been observed up to ~140 MV/m. Chemically etched and electropolished Nb are compared and no significant difference is observed up to ~140 MV/m. To

  14. 47 CFR 2.1091 - Radiofrequency radiation exposure evaluation: mobile devices.

    Science.gov (United States)

    2010-10-01

    ... transmission of a signal. In general, maximum average power levels must be used to determine compliance. (3) If... workers that can be easily re-located, such as wireless devices associated with a personal computer, are... Satellite Communications Services, the General Wireless Communications Service, the Wireless Communications...

  15. Potential formation in the plasma confinement region of a radio-frequency plugged linear device

    International Nuclear Information System (INIS)

    Fujita, Hideki; Kumazawa, Ryuhei; Howald, A.M.; Okamura, Shoichi; Sato, Teruyuki; Adati, Keizo; Garner, H.R.; Nishimura, Kiyohiko.

    1987-08-01

    Plasma potential formation in an open-ended plasma confinement system with RF plugging (the RFC-XX-M device) is investigated. The plasma potential in the central confinement region is measured with a heavy ion beam probe system and potentials at the RF plug section are measured with multi-grid energy analyzers. The measured plasma potential is compared with that deduced from the generalized Pastukhov formula. Results show that the plasma potential develops as an ambipolar potential to equate ion and electron end losses. During RF plugging, electrons are heated by Landau damping, while ions are not heated since adiabatic conditions apply during ion plugging in this experiment. (author)

  16. Comparison between Er:YAG laser and bipolar radiofrequency combined with infrared diode laser for the treatment of acne scars: Differential expression of fibrogenetic biomolecules may be associated with differences in efficacy between ablative and non-ablative laser treatment.

    Science.gov (United States)

    Min, Seonguk; Park, Seon Yong; Moon, Jungyoon; Kwon, Hyuck Hoon; Yoon, Ji Young; Suh, Dae Hun

    2017-04-01

    Fractional Er:YAG minimizes the risk associated with skin ablation. Infrared diode laser and radiofrequency have suggested comparable improvements in acne scar. We compared the clinical efficacy of Er:YAG laser and bipolar radiofrequency combined with diode laser (BRDL) for the treatment of acne scars. Moreover, acute molecular changes of cytokine profile associated with wound healing have been evaluated to suggest mechanisms of improvement of acne scar. Twenty-four subjects with mild-to-moderate acne scars were treated in a split-face manner with Er:YAG and BRDL, with two treatment sessions, 4 weeks apart. Objective and subjective assessments were done at baseline, 1, 3, 7 days after each treatment and 4 weeks after last treatment. Skin biopsy specimens were obtained at baseline, 1, 3, 7, 28 days after one session of treatment for investigation of molecular profile of acute skin changes by laser treatment. Investigator's Global Assessment representing the improvement degree shows 2.1 (50%) in fractional Er:YAG and 1.2 (25%) in BRDL. Er:YAG induced the later and higher peak expression of TGFβs and collagenases, whereas BRDL induced earlier and lower expression of TGFβ and collagenases, relatively. PPARγ dropped rapidly after a peak in Er:YAG-treated side, which is associated with tissue inhibitor of metalloproteinase (TIMP) expression. We observed higher expression of TIMP after Er:YAG treatment compared with BRDL by immunohistochemistry, which may be associated with the expression of upregulation of collagen fibers. The superior efficacy of Er:YAG to BRDL in the treatment of acne scars may be associated with higher expression of collagen which is associated with differential expression of TGFβs, collagenases, PPARγ, and TIMP. Lasers Surg. Med. 49:341-347, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. 21 CFR 882.4400 - Radiofrequency lesion generator.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency lesion generator. 882.4400 Section... (CONTINUED) MEDICAL DEVICES NEUROLOGICAL DEVICES Neurological Surgical Devices § 882.4400 Radiofrequency lesion generator. (a) Identification. A radiofrequency lesion generator is a device used to produce...

  18. Excellent nonlinearity of a selection device based on anti-series connected Zener diodes for ultrahigh-density bipolar RRAM arrays

    International Nuclear Information System (INIS)

    Li, Yingtao; Li, Rongrong; Wang, Yang; Tao, Chunlan; Fu, Liping; Gao, Xiaoping

    2015-01-01

    A crossbar array is usually used for the high-density application of a resistive random access memory (RRAM) device. However, the cross-talk interference limits the increase in the integration density. In this paper, anti-series connected Zener diodes as a selection device are proposed for bipolar RRAM arrays. Simulation results show that, by using the anti-series connected Zener diodes as a selection device, the readout margin is sufficiently improved compared to that obtained without a selection device or with anti-parallel connected diodes as the selection device. The maximum size of the crossbar arrays with anti-series connected Zener diodes as a selection device over 1 TB is estimated by theoretical simulation. In addition, the feasibility of using the anti-series connected Zener diodes as a selection device for bipolar RRAM is demonstrated experimentally. These results indicate that anti-series connected Zener diodes as a selection device opens up great opportunities to realize ultrahigh-density bipolar RRAM arrays. (paper)

  19. Radiofrequency energy in the arthroscopic treatment of knee chondral lesions: a systematic review.

    Science.gov (United States)

    Rocco, Papalia; Lorenzo, Diaz Balzani; Guglielmo, Torre; Michele, Paciotti; Nicola, Maffulli; Vincenzo, Denaro

    2016-03-01

    Cartilage debridement is one of the recommended procedures for the management of chondral defects. Radiofrequency probes allow to debride the cartilage, but may induce subchondral bone necrosis. Medline, Cochrane and Google Scholar were searched to identify studies on arthroscopic debridement of the articular cartilage of the knee using radiofrequency chondroplasty. The methodological quality of the studies was assessed using the Coleman methodology score (CMS). Monopolar and bipolar radiofrequency devices provide significantly better clinical outcomes, especially for patients with high-grade chondral lesions, compared with mechanical shaver only. Despite the original concerns regarding subchondral bone necrosis, low complication rates are reported. Heterogeneity in terms of type of device does not allow sound comparison of the published results. There is lack of evidence on the long-term effects of radiofrequency chondroplasty. Study methodology should be improved: the average Coleman methodology score was 56.2 out of 100. More comparative, well-designed and larger cohort trials are needed to ascertain whether radiofrequency chondroplasty offers long-term benefits over other simpler and more economical alternatives. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  20. Improvement in abdominal and flank contouring by a novel adipocyte-selective non-contact radiofrequency device.

    Science.gov (United States)

    Choi, Sun Young; Kim, Young Jae; Kim, So Yeon; Lee, Woo Jin; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Won, Chonghyun

    2018-05-07

    The demand for undergoing subcutaneous fat reduction has been gradually increasing, and there are many methods and devices for performing non-surgical and non-invasive fat reduction, such as high-intensity focused ultrasound, cryolipolysis, radiofrequency (RF) devices, and lasers. This study evaluated the efficacy and safety of a novel adipocyte-selective non-contact RF device for improving abdominal contouring in Asian subjects. Twenty-four Asian subjects with abundant subcutaneous abdominal and love handle fat tissues were enrolled in this prospective clinical study. They received six 45-min weekly treatments with an RF field device over the abdominal and love handle regions. The body mass index and abdominal circumference were measured at baseline and at 4 and 8 weeks post the last treatment. The thickness of the abdomen and depth of subcutaneous abdominal fat tissue were respectively assessed using calipers and abdominal ultrasonography. A subset of 15 subjects was selected by randomization for fat volume measurement via abdominal CT. For safety evaluation, serum lipid, and liver-related blood tests were performed at baseline and at the sixth treatment session. Subjects rated their heat perception level using a four point scale and their pain score using an 11-point visual analog scale during RF treatment. Twenty-four subjects (21 females and 3 males) completed this study with an 8-week follow-up. The average decreases in abdominal circumference at 4 and 8 weeks post treatment were 3.48 ± 2.11 cm (P < 0.001) and 5.12 ± 0.47 cm (P < 0.001), respectively. The average decreases in abdominal fat thickness at 4 and 8 weeks treatment were 0.27 ± 0.61 cm (P = 0.041) and 0.47 ± 0.60 cm (P = 0.001), respectively. The average decreases in subcutaneous fat tissue depth at 4 and 8 weeks post treatment were 0.16 ± 0.43 cm (P = 0.091) and 0.34 ± 0.39 cm (P < 0.001), respectively. However, there was no

  1. 21 CFR 886.4100 - Radiofrequency electrosurgical cautery apparatus.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency electrosurgical cautery apparatus... SERVICES (CONTINUED) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4100 Radiofrequency electrosurgical cautery apparatus. (a) Identification. A radiofrequency electrosurgical cautery apparatus is an AC...

  2. Painless, safe, and efficacious noninvasive skin tightening, body contouring, and cellulite reduction using multisource 3DEEP radiofrequency.

    Science.gov (United States)

    Harth, Yoram

    2015-03-01

    In the last decade, Radiofrequency (RF) energy has proven to be safe and highly efficacious for face and neck skin tightening, body contouring, and cellulite reduction. In contrast to first-generation Monopolar/Bipolar and "X -Polar" RF systems which use one RF generator connected to one or more skin electrodes, multisource radiofrequency devices use six independent RF generators allowing efficient dermal heating to 52-55°C, with no pain or risk of other side effects. In this review, the basic science and clinical results of body contouring and cellulite treatment using multisource radiofrequency system (Endymed PRO, Endymed, Cesarea, Israel) will be discussed and analyzed. © 2015 Wiley Periodicals, Inc.

  3. Novel Percutaneous Radiofrequency Ablation of Portal Vein Tumor Thrombus: Safety and Feasibility

    Energy Technology Data Exchange (ETDEWEB)

    Mizandari, Malkhaz [High Technology Medical Center, Tbilisi State Medical University (Georgia); Ao, Guokun [The 309 Hospital of People' s Liberation Army, Department on Oncology (China); Zhang Yaojun; Feng Xi [Imperial College London, Department of Surgery and Cancer (United Kingdom); Shen Qiang [The First Minimally Invasive Department of Eastern Hepatobiliary Surgery Hospital (China); Chen Minshan [Cancer Centre of Sun Yat-Sen University, Department of Hepatobiliary Surgery (China); Lau, Wan Yee [Chinese University of Hong Kong, Department of Surgery, Faculty of Medicine (Hong Kong); Nicholls, Joanna; Jiao Long; Habib, Nagy, E-mail: nagy.habib@imperial.ac.uk [Imperial College London, Department of Surgery and Cancer (United Kingdom)

    2013-02-15

    We report our experience of the safety of partial recanalization of the portal vein using a novel endovascular radiofrequency (RF) catheter for portal vein tumor thrombosis. Six patients with liver cancer and tumor thrombus in the portal vein underwent percutaneous intravascular radiofrequency ablation (RFA) using an endovascular bipolar RF device. A 0.035-inch guidewire was introduced into a tributary of the portal vein and through which a 5G guide catheter was introduced into the main portal vein. After manipulation of the guide catheter over the thrombus under digital subtraction angiography, the endovascular RF device was inserted and activated around the thrombus. There were no observed technique specific complications, such as hemorrhage, vessel perforation, or infection. Post-RFA portography showed partial recanalization of portal vein. RFA of portal vein tumor thrombus in patients with hepatocellular carcinoma is technically feasible and warrants further investigation to assess efficacy compared with current recanalization techniques.

  4. Use of an electrothermal bipolar sealing device in ligation of major mesenteric vessels during laparoscopic colorectal resection.

    LENUS (Irish Health Repository)

    Martin, S T

    2012-02-01

    BACKGROUND: A variety of approaches are available for division of major vascular structures during laparoscopic colorectal resection. Ultrasonic coagulating shears (UCS), vascular staplers, plastic or titanium clips and electrothermal bipolar vessel sealing (EBVS) are currently available. We report our experience with an EBVS device, LigaSure (Covidien AG), used in division of the ileocolic, middle colic and inferior mesenteric arteries during laparoscopic colorectal resection. METHODS: We report the immediate outcome of 802 consecutive unselected patients who underwent elective laparoscopic colorectal cancer resection performed with use of the LigaSure (5 and 10 mm) at our institution over a 5-year period. Operative procedures included right hemicolectomy (n = 180), left hemicolectomy (n = 96), sigmoid colectomy (n = 347) and anterior resection (n = 179). Data were collected from a prospectively maintained cancer database and operative records. The procedures were performed primarily by three consultant surgeons with an interest in laparoscopic colorectal resection. RESULTS: Of 802 cases in which the LigaSure device was employed to divide major vascular structures, immediate effective vessel sealing was achieved in 99.8% (n = 800). Two patients experienced related adverse events both following division of the inferior mesenteric artery with a 5 mm LigaSure. Both patients had immediate uncontrolled haemorrhage that required laparotomy. CONCLUSIONS: Use of the LigaSure device to seal and divide the major mesenteric vessels during laparoscopic colorectal resection is very effective, with a high success rate of 99.8%. Caution should be exercised in elderly atherosclerotic patients, particularly when using the 5-mm LigaSure device.

  5. Gas emission during laparoscopic colorectal surgery using a bipolar vessel sealing device: A pilot study on four patients

    Directory of Open Access Journals (Sweden)

    Gianella Michele

    2008-09-01

    Full Text Available Abstract Background Dissection during laparoscopic surgery produces smoke containing potentially toxic substances. The aim of the present study was to analyze smoke samples produced during laparoscopic colon surgery using a bipolar vessel sealing device (LigaSure™. Methods Four consecutive patients undergoing left-sided colectomy were enrolled in this pilot study. Smoke was produced by the use of LigaSure™. Samples (5,5l were evacuated from the pneumoperitoneum in a closed system into a reservoir. Analysis was performed with CO2-laser-based photoacoustic spectroscopy and confirmed by a Fourier-transform infrared spectrum. The detected spectra were compared to the available spectra of known toxins. Results Samples from four laparoscopic sigmoid resections were analyzed. No relevant differences were noted regarding patient and operation characteristics. The gas samples were stable over time proven by congruent control measurements as late as 24 h after sampling. The absorption spectra differed considerably between the patients. One broad absorption line at 100 ppm indicating H2O and several unknown molecules were detected. With a sensitivity of alpha min ca 10-5 cm-1 no known toxic substances like phenol or indole were identified. Conclusion The use of a vessel sealing device during laparoscopic surgery does not produce known toxic substances in relevant quantity. Further studies are needed to identify unknown molecules and to analyze gas emission under various conditions.

  6. Renal denervation with a percutaneous bipolar radiofrequency balloon catheter in patients with resistant hypertension: 6-month results from the REDUCE-HTN clinical study.

    Science.gov (United States)

    Sievert, Horst; Schofer, Joachim; Ormiston, John; Hoppe, Uta C; Meredith, Ian T; Walters, Darren L; Azizi, Michel; Diaz-Cartelle, Juan; Cohen-Mazor, Meital

    2015-02-01

    To evaluate the safety and efficacy of the balloon-based bipolar Vessix Renal Denervation System in treating patients with resistant hypertension. In this prospective, multicentre, single-arm study, 146 patients (age 58.6±10.5 years; 61% men) with office systolic blood pressure (BP) ≥160 mmHg despite ≥3 antihypertensive medications at maximally tolerated doses were treated with the Vessix System. Efficacy endpoints were reductions in office and 24-hour ambulatory systolic and diastolic BPs at six months. Acute and long-term safety, with a focus on the renal artery and estimated glomerular filtration rate (eGFR), were assessed. Baseline office and ambulatory BPs were 182.4±18.4/100.2±14.0 mmHg and 153.0±15.1/87.5±13.2 mmHg, respectively. No acute renal artery injury requiring intervention or serious periprocedural cardiovascular events occurred. At six months, office BP was reduced by 24.7±22.1/10.3±12.7 mmHg (prenal artery stenosis which required stenting. Mean eGFR remained stable. Renal artery denervation with the Vessix System reduced both office and ambulatory BP at six months in patients with resistant hypertension. Renal artery safety and renal function results are favourable.

  7. Cordless ultrasonic dissector versus advanced bipolar vessel sealing device for laparoscopic ovariectomy in dogs

    NARCIS (Netherlands)

    Spillebeen, Anneleen L; Janssens, Sara S D S; Thomas, Rachel E; Kirpensteijn, Jolle; van Nimwegen, Sebastiaan A

    OBJECTIVE: To compare Sonicision cordless ultrasonic dissector (SCUD) to LigaSure vessel sealing device (LVSD) for laparoscopic ovariectomy (Lap OVE) in dogs. STUDY DESIGN: Randomized, paired prospective clinical trial. ANIMALS: Client-owned dogs (n = 22) presented for elective Lap OVE. METHODS:

  8. Characterization of Radiation Hardened Bipolar Linear Devices for High Total Dose Missions

    Science.gov (United States)

    McClure, Steven S.; Harris, Richard D.; Rax, Bernard G.; Thorbourn, Dennis O.

    2012-01-01

    Radiation hardened linear devices are characterized for performance in combined total dose and displacement damage environments for a mission scenario with a high radiation level. Performance at low and high dose rate for both biased and unbiased conditions is compared and the impact to hardness assurance methodology is discussed.

  9. A pilot study of the efficacy of the POLARGEN® ultrahigh-frequency electric field (40.68 MHz) radiofrequency device in the treatment of facial contouring.

    Science.gov (United States)

    Kim, Miri; Lim, Jihong; Bae, Jung Min; Park, Hyun Jeong

    2017-11-01

    Various radiofrequency (RF) devices are used to treat skin laxity and face contouring, but few studies have examined ultrahigh-frequency (UHF) electric field (40.68 MHz) RF devices. To evaluate the efficacy and safety of a UHF electric field (40.68 MHz) RF device for skin tightening and face contouring. Ten patients each underwent four sessions of UHF electric field RF device treatment at 2-week intervals. Clinical improvement was evaluated with the patient satisfaction score using a six-point scale, and clinical photographs taken at every visit and 2 months after the RF treatment were assessed. Skin biopsies were obtained from one patient before the first treatment and immediately after the last treatment. Adverse reactions were recorded at every follow-up visit. All patients were women with a mean age of 51.7 ± 7.2 years. The mean satisfaction score was 4.5 ± 0.9 immediately after the last treatment session. Cheek, jawline, and neck enhancement and tightening were apparent in all patients. Side effects were minimal, and there were no burns or major complications. The UHF electric field RF device was effective for skin tightening and facial contouring, without significant adverse reactions.

  10. Inductance mode characteristics of a ceramic YBa2Cu3O7-x radio-frequency superconducting quantum interference device at 77 K

    DEFF Research Database (Denmark)

    Il'ichev, E. V.; Andreev, A. V.; Jacobsen, Claus Schelde

    1993-01-01

    Experimental results on some radio-frequency superconducting quantum interference device (rf-SQUID) signal properties are presented. The quantum interferometer was made of ceramic YBa2Cu3O7−x and was due to a low critical current operated in the inductance or nonhysteretic mode. With bias current...... as reference, amplitude variation, and phase shift of the voltage over the tank circuit coupled to the SQUID were measured simultaneously. It is shown that there is qualitative agreement between calculations based on the resistivity shunted junction model and the data. Moreover, using phase detection, signal...... instabilities predicted for the rf-SQUID inductance mode were observed. These signal instabilities may be exploited to enhance the transfer coefficient for measured flux-to-output signal. Journal of Applied Physics is copyrighted by The American Institute of Physics....

  11. Comparison of post-tonsillectomy pain with two different types of bipolar forceps: low temperature quantum molecular resonance device versus high temperature conventional electrocautery.

    Science.gov (United States)

    Chang, Hyun; Hah, J Hun

    2012-06-01

    The low temperature device did not show any advantages over the conventional high temperature electrocautery in terms of the postoperative pain, operation time, and complications in pediatric tonsillectomy. To compare post-tonsillectomy pain following the use of two different instruments with the same bipolar forceps techniques: low temperature quantum molecular resonance (QMR) device versus conventional high temperature electrocautery. Pediatric patients admitted from July 2008 through January 2009 were included. The participants underwent bilateral tonsillectomy; one side by the QMR device and the other by the bipolar electrocautery. The sides for each instrument were counterbalanced by the order of presentation. The postoperative pain was measured using the faces pain rating scale. In all, 33 patients with a mean age of 7.6 years were enrolled. The postoperative pain, operation time, and complications in 33 sides dissected by the electrocautery and 33 sides by the QMR device were compared. The average operation times with each device were not statistically different. The mean ratings of the perception of pain related to each instrument were not different on operation day and postoperative day 1, day 4, and day 7 (p = 0.133, 0.057, 0.625, and 1.0, respectively). There was no postoperative complication in any of the patients.

  12. An electronic image processing device featuring continuously selectable two-dimensional bipolar filter functions and real-time operation

    International Nuclear Information System (INIS)

    Charleston, B.D.; Beckman, F.H.; Franco, M.J.; Charleston, D.B.

    1981-01-01

    A versatile electronic-analogue image processing system has been developed for use in improving the quality of various types of images with emphasis on those encountered in experimental and diagnostic medicine. The operational principle utilizes spatial filtering which selectively controls the contrast of an image according to the spatial frequency content of relevant and non-relevant features of the image. Noise can be reduced or eliminated by selectively lowering the contrast of information in the high spatial frequency range. Edge sharpness can be enhanced by accentuating the upper midrange spatial frequencies. Both methods of spatial frequency control may be adjusted continuously in the same image to obtain maximum visibility of the features of interest. A precision video camera is used to view medical diagnostic images, either prints, transparencies or CRT displays. The output of the camera provides the analogue input signal for both the electronic processing system and the video display of the unprocessed image. The video signal input to the electronic processing system is processed by a two-dimensional spatial convolution operation. The system employs charged-coupled devices (CCDs), both tapped analogue delay lines (TADs) and serial analogue delay lines (SADs), to store information in the form of analogue potentials which are constantly being updated as new sampled analogue data arrive at the input. This information is convolved with a programmed bipolar radially symmetrical hexagonal function which may be controlled and varied at each radius by the operator in real-time by adjusting a set of front panel controls or by a programmed microprocessor control. Two TV monitors are used, one for processed image display and the other for constant reference to the original image. The working prototype has a full-screen display matrix size of 200 picture elements per horizontal line by 240 lines. The matrix can be expanded vertically and horizontally for the

  13. New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

    International Nuclear Information System (INIS)

    Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun

    2017-01-01

    To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments

  14. New radiofrequency device to reduce bleeding after core needle biopsy: Experimental study in a porcine liver model

    Energy Technology Data Exchange (ETDEWEB)

    Lim, Sang Hyeok; Rhim, Hyun Chul; Lee, Min Woo; Song, Kyoung Doo; Kang, Tae Wook; Kim, Young Sun; Lim, Hyo Keun [Dept. of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of)

    2017-01-15

    To evaluate the in vivo efficiency of the biopsy tract radiofrequency ablation for hemostasis after core biopsy of the liver in a porcine liver model, including situations with bleeding tendency and a larger (16-gauge) core needle. A preliminary study was performed using one pig to determine optimal ablation parameters. For the main experiment, four pigs were assigned to different groups according to heparinization use and biopsy needle caliber. In each pig, 14 control (without tract ablation) and 14 experimental (tract ablation) ultrasound-guided core biopsies were performed using either an 18- or 16-gauge needle. Post-biopsy bleeding amounts were measured by soaking up the blood for five minutes. The results were compared using the Mann-Whitney U test. The optimal parameters for biopsy tract ablation were determined as a 2-cm active tip electrode set at 40-watt with a tip temperature of 70–80℃. The bleeding amounts in all experimental groups were smaller than those in the controls; however they were significant in the non-heparinized pig biopsied with an 18-gauge needle and in two heparinized pigs (p < 0.001). In the heparinized pigs, the mean blood loss in the experimental group was 3.5% and 13.5% of the controls biopsied with an 18- and 16-gauge needle, respectively. Radiofrequency ablation of hepatic core biopsy tract ablation may reduce post-biopsy bleeding even under bleeding tendency and using a larger core needle, according to the result from in vivo porcine model experiments.

  15. Fentanyl Iontophoretic Transdermal System (IONSYS(®)) can be Safely used in the Hospital Environment with X-Rays, Computerized Tomography and Radiofrequency Identification Devices.

    Science.gov (United States)

    Lemke, John; Sardariani, Edmond; Phipps, Joseph Bradley; Patel, Niki; Itri, Loretta M; Caravelli, James; Viscusi, Eugene R

    2016-09-01

    Fentanyl iontophoretic transdermal system (fentanyl ITS, IONSYS(®)) is a patient-controlled analgesia system used for the management of acute postoperative pain, designed to be utilized in a hospital setting. The objective of the two studies was to determine if fentanyl ITS could be safely used with X-rays, computerized tomography (CT) scans and radiofrequency identification (RFID) devices. The ITS system has two components: controller and drug unit; the studies utilized ITS systems without fentanyl, referred to as the ITS Placebo system. The first study evaluated the effect of X-radiation on the operation of an ITS Placebo system. Five ITS Placebo systems were exposed to X-rays (20 and 200 mSv total radiation dose-the 200 mSv radiation dose represents a tenfold higher exposure than in clinical practice) while operating in the Ready Mode and five were exposed while operating in the Dose Mode. The second study evaluated the effect of RFID (worst-case scenario of direct contact with an RFID transmitter) on the operation of an ITS Placebo system. During these tests, observations of the user interface and measurements of output voltage confirmed proper function throughout all operational modes (Ready Mode, Dose Mode, End-of-Use Mode, and End-of-Life Mode). The ITS Placebo system met all specifications and no functional anomalies were observed during and following X-ray exposure at two radiation dose levels or exposure at six different combinations of RFID frequencies and field strengths. The performance of the ITS system was unaffected by X-ray exposure levels well beyond those associated with diagnostic X-rays and CT scans, and by exposure to radiofrequency field strengths typically generated by RFID devices. These results provide added confidence to clinicians that the fentanyl ITS system does not need to be removed during diagnostic X-rays and CT scans and can also be utilized in close proximity to RFID devices. The studies and writing of this manuscript were

  16. Imaging-Guided Percutaneous Radiofrequency Ablation of Adrenal Metastases: Preliminary Results at a Single Institution with a Single Device

    International Nuclear Information System (INIS)

    Carrafiello, G.; Lagana, D.; Recaldini, C.; Giorgianni, A.; Ianniello, A.; Lumia, D.; D'Ambrosio, A.; Petulla, M.; Dionigi, G.; Fugazzola, C.

    2008-01-01

    The aim of this study was to show the feasibility, safety, imaging appearance, and short-term efficacy of image-guided percutaneous radiofrequency ablation (RFA) of adrenal metastases (AM). Seven imaging-guided percutaneous RFA treatments were performed in six patients (two men and four women; mean age, 67.2 years; range, 55-74 years) with six AM who were referred to our institution from 2003 to 2006. One patient was treated twice for recurrence after first treatment. The average diameter of the treated AM was 29 mm (range, 15-40 mm). In all patients, the diagnosis was obtained with CT current protocols in use at our institution and confirmed by pathology with an image-guided biopsy. No major complications occurred. In one patient shortly after initiation of the procedure, severe hypertension was noted; another patient developed post-RFA syndrome. In five of six lesions, there was no residual enhancement of the treated tumor. In one patient CT examination showed areas of residual enhancement of the tumor after treatment. Our preliminary results suggest that imaging-guided percutaneous RFA is effective for local control of AM, without major complications and with a low morbidity rate related to the procedure. Long-term follow-up will need to be performed and appropriate patient selection criteria will need to be determined in future randomized trials.

  17. Influence of radiofrequency surgery on architecture of the palatine tonsils.

    Science.gov (United States)

    Plzak, Jan; Macokova, Pavla; Zabrodsky, Michal; Kastner, Jan; Lastuvka, Petr; Astl, Jaromir

    2014-01-01

    Radiofrequency surgery is a widely used modern technique for submucosal volume reduction of the tonsils. So far there is very limited information on morphologic changes in the human tonsils after radiofrequency surgery. We performed histopathological study of tonsillectomy specimens after previous bipolar radiofrequency induced thermotherapy (RFITT). A total of 83 patients underwent bipolar RFITT for hypertrophy of palatine tonsils. Tonsil volume reduction was measured by 3D ultrasonography. Five patients subsequently underwent tonsillectomy. Profound histopathological examination was performed to determine the effect of RFITT on tonsillar architecture. All tonsillectomy specimens showed the intact epithelium, intact germinal centers, normal vascularization, and no evidence of increased fibrosis. No microscopic morphological changes in tonsillectomy specimens after bipolar RFITT were observed. RFITT is an effective submucosal volume reduction procedure for treatment of hypertrophic palatine tonsils with no destructive effect on microscopic tonsillar architecture and hence most probably no functional adverse effect.

  18. Bipolar Disorder

    Science.gov (United States)

    Bipolar disorder is a serious mental illness. People who have it go through unusual mood changes. They go ... The down feeling is depression. The causes of bipolar disorder aren't always clear. It runs in families. ...

  19. Treating multiple body parts for skin laxity and fat deposits using a novel focused radiofrequency device with an ultrasound component: Safety and efficacy study.

    Science.gov (United States)

    Chilukuri, Suneel; Denjean, Dominique; Fouque, Linda

    2017-12-01

    Growing demand for noninvasive skin tightening and reduction in fat results in an increasing pressure for devices with good clinical efficacy, consistency of results, and high patient comfort. The objective was to validate clinical efficacy and versatility of a novel device, which combines radiofrequency (RF) and ultrasound for treating skin laxity and fat deposits. We treated 34 subjects with facial skin laxity and/or abundant body or arm fat deposits. Subjects were divided based on their indications. Ten subjects received treatments to the face, 7 subjects to arms, 8 subjects to thighs, and 9 subjects on abdomen. All patients received 4 treatments on a weekly basis. Photographs of patients were assessed by blinded evaluators to recognize the baseline images from the 3-month follow-up images. Patient comfort and satisfaction were evaluated using a 5-point Likert scale questionnaire. Any adverse events were recorded. Patient images were correctly recognized in >90% of cases in all study groups. Patient questionnaires showed overall satisfaction with the therapy course and results. On a scale of 1 to 5, the patients agreed (4.1) that they are satisfied with the results that the treatment is comfortable (4.1) and that they are satisfied with the treatment time (4.1). No adverse events were reported. Consistent clinical efficacy was confirmed across all the treated areas, together with high patient comfort and satisfaction. We conclude the device is a highly versatile solution that can deliver results across body parts and different indications. © 2017 The Authors Journal of Cosmetic Dermatology Published by Wiley Periodicals, Inc.

  20. Evaluation of the safety and efficacy of a monopolar nonablative radiofrequency device for the improvement of vulvo-vaginal laxity and urinary incontinence.

    Science.gov (United States)

    Lalji, Shelena; Lozanova, Paula

    2017-06-01

    Vaginal childbirth, natural process of aging, congenital factors, and surgical interventions are considered the main causes of vulvo-vaginal laxity driven by changes in collagen and elastin fibers. This causes a loss of strength and flexibility within the vaginal wall. As a result, women may experience lack of sensation and stress urinary incontinence (SUI)-the condition of involuntary loss of urine associated with activities that cause an increase in intra-abdominal pressure (eg, sneezing, coughing, and lifting). Both vaginal laxity and urinary incontinence significantly affect patients' quality of life (QoL). The aim of this study was to evaluate efficacy and safety of a noninvasive radiofrequency device when used to treat SUI and vulvo-vaginal laxity through its heating effect which stimulates collagen and elastin fibers. Twenty-seven women (average age 44.78±10.04 years) with indications of mild/moderate SUI as well as vulvo-vaginal laxity were treated with a monopolar radiofrequency device. The treatment course consisted of three once-a-week sessions. Each session included intravaginal treatment followed by treatment of labia majora and the perineum. Improvement in the SUI condition was evaluated by applying the International Consultation on Incontinence Questionnaire - Urinary Incontinence Short Form (ICIQ-UI SF). Data were collected at the baseline, after the last treatment and at 1-month follow-up visit. Vaginal laxity was assessed by subjective vulvo-vaginal laxity questionnaire (VVLQ). Data were collected before the 1st treatment and during the 1-month follow-up visit. Patient's satisfaction was recorded using a satisfaction questionnaire. Data were collected after the last treatment and at the 1-month follow-up visit. Any adverse events related to the treatments were monitored. On a scale of 0 to 5, the average frequency of urine leak improved from "2-3 times a week" (2.15±1.03 points prior to treatment) to "once a week" (1.00±0.78 points post

  1. Radiofrequency ablation of hepatocellular carcinoma: Mono or multipolar?

    Science.gov (United States)

    Cartier, Victoire; Boursier, Jérôme; Lebigot, Jérôme; Oberti, Frédéric; Fouchard-Hubert, Isabelle; Aubé, Christophe

    2016-03-01

    Thermo-ablation by radiofrequency is recognized as a curative treatment for early-stage hepatocellular carcinoma. However, local recurrence may occur because of incomplete peripheral tumor destruction. Multipolar radiofrequency has been developed to increase the size of the maximal ablation zone. We aimed to compare the efficacy of monopolar and multipolar radiofrequency for the treatment of hepatocellular carcinoma and determine factors predicting failure. A total of 171 consecutive patients with 214 hepatocellular carcinomas were retrospectively included. One hundred fifty-eight tumors were treated with an expandable monopolar electrode and 56 with a multipolar technique using several linear bipolar electrodes. Imaging studies at 6 weeks after treatment, then every 3 months, assessed local effectiveness. Radiofrequency failure was defined as persistent residual tumor after two sessions (primary radiofrequency failure) or local tumor recurrence during follow-up. This study received institutional review board approval (number 2014/77). Imaging showed complete tumor ablation in 207 of 214 lesions after the first session of radiofrequency. After a second session, only two cases of residual viable tumor were observed. During follow-up, there were 46 local tumor recurrences. Thus, radiofrequency failure occurred in 48/214 (22.4%) cases. By multivariate analysis, technique (P radiofrequency failure. Failure rate was lower with the multipolar technique for tumors radiofrequency, multipolar radiofrequency improves tumor ablation with a subsequent lower rate of local tumor recurrence. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

  2. Oxygen-ion-migration-modulated bipolar resistive switching and complementary resistive switching in tungsten/indium tin oxide/gold memory device

    Science.gov (United States)

    Wu, Xinghui; Zhang, Qiuhui; Cui, Nana; Xu, Weiwei; Wang, Kefu; Jiang, Wei; Xu, Qixing

    2018-06-01

    In this paper, we report our investigation of room-temperature-fabricated tungsten/indium tin oxide/gold (W/ITO/Au) resistive random access memory (RRAM), which exhibits asymmetric bipolar resistive switching (BRS) behavior. The device displays good write/erase endurance and data retention properties. The device shows complementary resistive switching (CRS) characteristics after controlling the compliance current. A WO x layer electrically formed at the W/ITO in the forming process. Mobile oxygen ions within ITO migrate toward the electrode/ITO interface and produce a semiconductor-like layer that acts as a free-carrier barrier. The CRS characteristic here can be elucidated in light of the evolution of an asymmetric free-carrier blocking layer at the electrode/ITO interface.

  3. Influence of Thermal Annealing Treatment on Bipolar Switching Properties of Vanadium Oxide Thin-Film Resistance Random-Access Memory Devices

    Science.gov (United States)

    Chen, Kai-Huang; Cheng, Chien-Min; Kao, Ming-Cheng; Chang, Kuan-Chang; Chang, Ting-Chang; Tsai, Tsung-Ming; Wu, Sean; Su, Feng-Yi

    2017-04-01

    The bipolar switching properties and electrical conduction mechanism of vanadium oxide thin-film resistive random-access memory (RRAM) devices obtained using a rapid thermal annealing (RTA) process have been investigated in high-resistive status/low-resistive status (HRS/LRS) and are discussed herein. In addition, the resistance switching properties and quality improvement of the vanadium oxide thin-film RRAM devices were measured by x-ray diffraction (XRD) analysis, x-ray photoelectron spectrometry (XPS), scanning electron microscopy (SEM), atomic force microscopy (AFM), and current-voltage ( I- V) measurements. The activation energy of the hopping conduction mechanism in the devices was investigated based on Arrhenius plots in HRS and LRS. The hopping conduction distance and activation energy barrier were obtained as 12 nm and 45 meV, respectively. The thermal annealing process is recognized as a candidate method for fabrication of thin-film RRAM devices, being compatible with integrated circuit technology for nonvolatile memory devices.

  4. Evaluation of reproductive function of female rats exposed to radiofrequency fields (27. 12 MHz) near a shortwave diathermy device

    Energy Technology Data Exchange (ETDEWEB)

    Brown-Woodman, P.D.; Hadley, J.A.; Richardson, L.; Bright, D.; Porter, D.

    1989-04-01

    In recent years, there has been increased concern regarding effects of operator exposure to the electromagnetic (EM) field associated with shortwave diathermy devices. The present study was designed to investigate the effects, on rats, of repeated exposure to such an EM field. Following repeated exposure for 5 wk, a reduction in fertility occurred as indicated by a reduced number of matings in exposed rats compared to sham-irradiated rats and a reduction in the number of rats that conceived after mating. The data suggest that female operators could experience reduced fertility, if they remained close to the console for prolonged periods. This has particular significant for the physiotherapy profession.

  5. Non-surgical radiofrequency facelift.

    Science.gov (United States)

    Narins, David J; Narins, Rhoda S

    2003-10-01

    There has been considerable interest in using non-ablative methods to rejuvenate the skin. The ThermaCool TC (Thermage Inc.) is a radiofrequency (RF) device that has been introduced to induce tightening of the address the problem of skin via a uniform volumetric heating into the deep dermis tightening, resulting in a 'non-surgical facelift'. Radiofrequency produces a uniform volumetric heating into the deep dermis. Twenty treatment areas in 17 patients were treated to evaluate the efficacy and safety of RF treatment to the brow and jowls. The technique was found to produce gradual tightening in most patients, and there were no adverse effects.

  6. An in-depth description of bipolar resistive switching in Cu/HfOx/Pt devices, a 3D kinetic Monte Carlo simulation approach

    Science.gov (United States)

    Aldana, S.; Roldán, J. B.; García-Fernández, P.; Suñe, J.; Romero-Zaliz, R.; Jiménez-Molinos, F.; Long, S.; Gómez-Campos, F.; Liu, M.

    2018-04-01

    A simulation tool based on a 3D kinetic Monte Carlo algorithm has been employed to analyse bipolar conductive bridge RAMs fabricated with Cu/HfOx/Pt stacks. Resistive switching mechanisms are described accounting for the electric field and temperature distributions within the dielectric. The formation and destruction of conductive filaments (CFs) are analysed taking into consideration redox reactions and the joint action of metal ion thermal diffusion and electric field induced drift. Filamentary conduction is considered when different percolation paths are formed in addition to other conventional transport mechanisms in dielectrics. The simulator was tuned by using the experimental data for Cu/HfOx/Pt bipolar devices that were fabricated. Our simulation tool allows for the study of different experimental results, in particular, the current variations due to the electric field changes between the filament tip and the electrode in the High Resistance State. In addition, the density of metallic atoms within the CF can also be characterized along with the corresponding CF resistance description.

  7. Bipolar disorders

    DEFF Research Database (Denmark)

    Vieta, Eduard; Berk, Michael; Schulze, Thomas G

    2018-01-01

    Bipolar disorders are chronic and recurrent disorders that affect >1% of the global population. Bipolar disorders are leading causes of disability in young people as they can lead to cognitive and functional impairment and increased mortality, particularly from suicide and cardiovascular disease...... and accurate diagnosis is difficult in clinical practice as the onset of bipolar disorder is commonly characterized by nonspecific symptoms, mood lability or a depressive episode, which can be similar in presentation to unipolar depression. Moreover, patients and their families do not always understand...... a bipolar disorder from other conditions. Optimal early treatment of patients with evidence-based medication (typically mood stabilizers and antipsychotics) and psychosocial strategies is necessary....

  8. Percutaneous ultrasound-guided radiofrequency ablation for kidney tumors in patients with surgical risk

    International Nuclear Information System (INIS)

    Salagierski, Marek; Salagierski, Maciej; Sosnowski, Marek; Salagierska-Barwinska, Anna

    2006-01-01

    The aim of this study was to describe our experience with percutaneous ultrasound-guided radiofrequency ablation of kidney tumors. From July 2002 to August 2005, 45 radiofrequency ablations (RFA) in 42 selected patients with kidney tumor were performed. The patients had either contraindications to surgery procedures or had a solitary kidney. The average tumor size was 37.5 mm (range, 18-59 mm) with the mean age of 68 years (range, 28-83 years). RFA were performed based on radiographic findings. Needle biopsy was made only twice. Monopolar Cool-tip Tyco or bipolar Celon Olympus radiofrequency devices were used. The procedure was performed under conscious sedation with local anesthesia. Treatment efficacy was assessed by computed tomography and by Doppler ultrasound. The absence of contrast enhancement on computed tomography was considered to be a successful treatment. The average follow up was 14 months (range, 3-36 months). In 42 tumors (93%), total absence of contrast enhancement was obtained after the initial RFA and in three tumors (7%) after the second ablation session. There were no complications following 41 procedures, including all ablations in small (<35 mm) renal masses. In four procedures, minor complications were observed. All patients are alive. There has been no need for chronic hemodialysis and, until now, we have not observed any local recurrences with the exception of one metastasis to an ipsilateral adrenal gland. RFA of kidney tumors is a promising alternative treatment which could be considered for patients who are not suitable for surgery. (author)

  9. 21 CFR 870.2910 - Radiofrequency physiological signal transmitter and receiver.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radiofrequency physiological signal transmitter... Devices § 870.2910 Radiofrequency physiological signal transmitter and receiver. (a) Identification. A radiofrequency physiological signal transmitter and receiver is a device used to condition a physiological signal...

  10. Radiofrequency radiation

    International Nuclear Information System (INIS)

    Elder, J.A.; Czerski, P.A.; Stuchly, M.A.; Mild, K.H.; Sheppard, A.R.

    1989-01-01

    High-level radiofrequency radiation is a source of thermal energy that carries all of the known implications of heating for biological systems, including burns, temporary and permanent changes in reproduction, cataracts, and death. In general, no changes in chromosomes, DNA or the reproductive potential of animals exposed to RF radiation have been reported in the absence of significant rises in temperature, though there are limited data on DNA and chromosomal changes at non-thermal levels. Human data are currently limited and do not provide adequate information about the relationship between prolonged low-level RF radiation exposure and increased mortality or morbidity, including cancer incidence. In epidemiological studies and clinical reports of RF effects in man, the problems of quantification are numerous and include uncertainties about ''dose'', health effects, latent periods, dose-response relationships, and interactions with other physical or chemical agents. 228 refs, 6 figs, 2 tabs

  11. Bipolar Disorder.

    Science.gov (United States)

    Spearing, Melissa

    Bipolar disorder, a brain disorder that causes unusual shifts in a person's mood, affects approximately one percent of the population. It commonly occurs in late adolescence and is often unrecognized. The diagnosis of bipolar disorder is made on the basis of symptoms, course of illness, and when possible, family history. Thoughts of suicide are…

  12. Discharge dynamics of self-oriented microplasma coupling between cross adjacent cavities in micro-structure device driven by a bipolar pulse waveform

    Science.gov (United States)

    Wang, Yaogong; Zhang, Xiaoning; Liu, Lingguang; Zhou, Xuan; Liu, Chunliang; Zhang, Qiaogen

    2018-04-01

    The excitation dynamics and self-oriented plasma coupling of a micro-structure plasma device with a rectangular cross-section are investigated. The device consists of 7 × 7 microcavity arrays, which are blended into a unity by a 50 μm-thick bulk area above them. The device is operated in argon with a pressure of 200 Torr, driven by a bipolar pulse waveform of 20 kHz. The discharge evolution is characterized by means of electrical measurements and optical emission profiles. It has been found that different emission patterns are observed within microcavities. The formation of these patterns induced by the combined action between the applied electric field and surface deactivation is discussed. The microplasma distribution in some specific regions along the diagonal direction of cavities in the bulk area is observed, and self-oriented microplasma coupling is explored, while the plasma interaction occurred between cross adjacent cavities, contributed by the ionization wave propagation. The velocity of ionization wave propagation is measured to be 1.2 km/s to 3.5 km/s. The exploration of this plasma interaction in the bulk area is of value to applications in electromagnetics and signal processing.

  13. Is the bipolar vessel sealer device an effective tool in robotic surgery? A retrospective analysis of our experience and a meta-analysis of the literature about different robotic procedures by investigating operative data and post-operative course.

    Science.gov (United States)

    Ortenzi, Monica; Ghiselli, Roberto; Baldarelli, Maddalena; Cardinali, Luca; Guerrieri, Mario

    2018-04-01

    The latest robotic bipolar vessel sealing tools have been described to be effective allowing to perform procedures with reduced blood loss and shorter operative times. The aim of this study was to assess the efficacy and reliability of these devices applied in different robotic procedures. All robotic operations, between 2014 and 2016, were performed using the EndoWrist One VesselSealer (EWO, Intuitive Surgical, Sunnyvale, CA), a bipolar fully wristed device. Data, including age, gender, body mass index (BMI), were collected. Robot docking time, intraoperative blood loss, robot malfunctioning and overall operative time were analyzed. A meta-analysis of the literature was carried out to point the attention to three different parameters (mean blood loss, operating time and hospital stay) trying to identify how different coagulation devices may affect them. In 73 robotic procedures, the mean operative time was 118.2 minutes (75-125 minutes). Mean hospital stay was four days (2-10 days). There were two post-operative complications (2.74%). The bipolar vessel sealer offers the efficacy of bipolar diathermy and the advantages of a fully wristed instrument. It does not require any change of instruments for coagulation or involvement of the bedside assistant surgeon. These characteristics lead to a reduction in operative time.

  14. Effects on the Distal Radioulnar Joint of Ablation of Triangular Fibrocartilage Complex Tears With Radiofrequency Energy.

    Science.gov (United States)

    Huber, Michaela; Loibl, Markus; Eder, Christoph; Kujat, Richard; Nerlich, Michael; Gehmert, Sebastian

    2016-11-01

    This cadaver study investigated the temperature profile in the wrist joint and distal radioulnar joint (DRUJ) during radiofrequency energy (RFE) application for triangular fibrocartilage complex resection. An arthroscopic partial resection of the triangular fibrocartilage complex using monopolar and bipolar RFE was simulated in 14 cadaver limbs. The temperature was recorded simultaneously in the DRUJ and at 6 other anatomic locations of the wrist during RFE application. The mean temperature in the DRUJ was 43.3 ± 8.2°C for the bipolar system in the ablation mode (60 W) and 30.4 ± 3.4°C for the monopolar system in the cut mode (20 W) after 30 seconds. The highest measured temperature in the DRUJ was 54.3°C for the bipolar system and 68.1°C for the monopolar system. The application of RFE for debridement or resection of the triangular fibrocartilage complex in a clinical setting can induce peak temperatures that might cause damage to the cartilage of the DRUJ. Bipolar systems produce higher mean temperatures than monopolar devices. RFE application increases the mean temperature in the DRUJ after 30 seconds to a level that may jeopardize cartilage tissue. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

  15. Evaluation of the clinical efficacy of fractional radiofrequency microneedle treatment in acne scars and large facial pores.

    Science.gov (United States)

    Cho, Soo Ick; Chung, Bo Young; Choi, Min Gyu; Baek, Ji Hwoon; Cho, Hee Jin; Park, Chun Wook; Lee, Cheol Heon; Kim, Hye One

    2012-07-01

    Fractional technology overcomes the problems of ablative lasers, such as inaccurate depth control and damage to the epidermis. Minimally invasive fractional radiofrequency microneedle devices allow for more-selective heating of the dermis. To evaluate the clinical efficacy of fractional radiofrequency microneedle (ERM) treatment in acne scars and large facial pores. Thirty patients with acne scars and large facial pores were enrolled. Bipolar radiofrequency energy was delivered to the skin through the electrodes of the FRM device. Skin lesions were evaluated according to grade of acne scars, Investigator Global Assessment of large pores, skin surface roughness, transepidermal water loss (TEWL), dermal density, microscopic and composite image, sebum measurement, and questionnaires regarding patient satisfaction. The grade of acne scars and Investigator Global Assessment of large pores improved in more than 70% of all patients. Skin surface roughness, dermal density, and microscopic and composite images also improved, whereas TEWL and sebum measurement did not change. Clinical improvement from FRM treatment appeared to be related to dermal matrix regeneration. FRM treatment may be effective in improving acne scars and facial pores. © 2012 by the American Society for Dermatologic Surgery, Inc. Published by Wiley Periodicals, Inc.

  16. A 12-week clinical and instrumental study evaluating the efficacy of a multisource radiofrequency home-use device for wrinkle reduction and improvement in skin tone, skin elasticity, and dermal collagen content.

    Science.gov (United States)

    Sadick, Neil S; Harth, Yoram

    2016-12-01

    This study was performed in order to evaluate the safety and efficacy of a new handheld home-use multisource radiofrequency device on facial rejuvenation. Forty-seven male and female subjects were enrolled. All subjects received a NEWA ® 3DEEP ™ home-use device (EndyMed Medical, Caesarea, Israel) to be used on facial skin three times per week for the first four weeks and then reduced to two times per week for the following eight weeks. Assessments included expert clinical grading for efficacy, instrumental evaluation, image analysis, and photography. Forty-five subjects completed the study; all subjects reported the treatment to be painless with only mild erythema lasting up to 15 minutes post-treatment. No other adverse events were reported. Statistically significant improvements were noted in the appearance of marionette lines, skin brightness, elasticity, firmness, lift (facial), lift (jawline), texture/smoothness, tone, and radiance/luminosity by expert visual assessment. Statistically significant improvements in skin firmness and elasticity were found using a Cutometer MPA 580, as well as in collagen and hemoglobin content of the skin using a SIAscope. The results of this study indicate that the NEWA ® multisource radiofrequency home-use device is effective in self-administered skin rejuvenation.

  17. WORKSHOPS: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991

  18. WORKSHOPS: Radiofrequency superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1992-01-15

    In the continual push towards higher energy particle beams, superconducting radiofrequency techniques now play a vital role, highlighted in the fifth workshop on radiofrequency superconductivity, held at DESY from 19 - 24 August 1991.

  19. 77 FR 43535 - Grantee Codes for Certified Radiofrequency Equipment

    Science.gov (United States)

    2012-07-25

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [FCC 12-60] Grantee Codes for Certified Radiofrequency Equipment AGENCY: Federal Communications Commission. ACTION: Final rule. SUMMARY: This document... authorization program for radiofrequency (RF) devices under part 2 of its rules. This program is one of the...

  20. Dose enhancement effects of X ray radiation in bipolar transistors

    International Nuclear Information System (INIS)

    Chen Panxun

    1997-01-01

    The author has presented behaviour degradation and dose enhancement effects of bipolar transistors in X ray irradiation environment. The relative dose enhancement factors of X ray radiation were measured in bipolar transistors by the experiment methods. The mechanism of bipolar device dose enhancement was investigated

  1. A systematic review on radiofrequency assisted laparoscopic liver resection: Challenges and window to excel.

    Science.gov (United States)

    Reccia, Isabella; Kumar, Jayant; Kusano, Tomokazu; Zanellato, Artur; Draz, Ahmed; Spalding, Duncan; Habib, Nagy; Pai, Madhava

    2017-09-01

    Laparoscopic liver resection has progressively gained acceptance as a safe and effective procedure in the treatment of benign and malignant liver neoplasms. However, blood loss remains the major challenge in liver surgery. Several techniques and devices have been introduced in liver surgery in order to minimize intraoperative haemorrhage during parenchymal transection. Radiofrequency (RF)-assisted liver resection has been shown to be an effective method to minimize bleeding in open and laparoscopic liver resection. A number of RF devices for parenchymal transection have been designed to assist laparoscopic liver resections. Here we have reviewed the results of various RF devices in laparoscopic liver resection. A total 15 article were considered relevant for the evaluation of technical aspects and outcomes of RF-assisted liver resections in laparoscopic procedures. In these studies, 176 patients had laparoscopic liver resection using RF-assisted parenchymal coagulation. Two monopolar and three bipolar devices were employed. Blood loss was limited in most of the studies. The need of blood transfusions was limited to two cases in all the series. Conversion was necessary due to bleeding in 3 cases. Operative and transection times varied between studies. However, RF-assisted resection with bipolar devices appeared to have taken less time in comparison to other RF devices. RF-related complications were minimum, and only one case of in-hospital death due to hepatic failure was reported. Although RF has been used in a small minority of laparoscopic liver resections, laparoscopic RF-assisted liver resection for benign and malignant disease is a safe and feasible procedure associated with reduction in blood loss, low morbidity, and lower hospital mortality rates. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Radiofrequency Ablation of Lung Tumors

    Science.gov (United States)

    ... News Physician Resources Professions Site Index A-Z Radiofrequency Ablation (RFA) / Microwave Ablation (MWA) of Lung Tumors ... and Microwave Ablation of Lung Tumors? What are Radiofrequency and Microwave Ablation of Lung Tumors? Radiofrequency ablation, ...

  3. Bipolar Disorder

    Science.gov (United States)

    ... one or other traumatic event Drug or alcohol abuse Complications Left untreated, bipolar disorder can result in serious problems that affect every area of your life, such as: Problems related to drug and alcohol use Suicide or suicide attempts Legal or financial problems Damaged ...

  4. Neutrality in bipolar structures

    DEFF Research Database (Denmark)

    Montero, Javier; Rodríguez, J. Tinguaro; Franco, Camilo

    2014-01-01

    In this paper, we want to stress that bipolar knowledge representation naturally allows a family of middle states which define as a consequence different kinds of bipolar structures. These bipolar structures are deeply related to the three types of bipolarity introduced by Dubois and Prade, but our...... approach offers a systematic explanation of how such bipolar structures appear and can be identified....

  5. Bipolar Treatment: Are Bipolar I and Bipolar II Treated Differently?

    Science.gov (United States)

    ... The diagnosis and management of bipolar I and bipolar II disorders: Clinical practice update. Mayo Clinic Proceedings. 2017;92:1532. Haynes PL, et al. Social rhythm therapies for mood disorders: An update. Current Psychiatry Reports. ...

  6. Bipolar electrochemistry.

    Science.gov (United States)

    Fosdick, Stephen E; Knust, Kyle N; Scida, Karen; Crooks, Richard M

    2013-09-27

    A bipolar electrode (BPE) is an electrically conductive material that promotes electrochemical reactions at its extremities (poles) even in the absence of a direct ohmic contact. More specifically, when sufficient voltage is applied to an electrolyte solution in which a BPE is immersed, the potential difference between the BPE and the solution drives oxidation and reduction reactions. Because no direct electrical connection is required to activate redox reactions, large arrays of electrodes can be controlled with just a single DC power supply or even a battery. The wireless aspect of BPEs also makes it possible to electrosynthesize and screen novel materials for a wide variety of applications. Finally, bipolar electrochemistry enables mobile electrodes, dubbed microswimmers, that are able to move freely in solution. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Transtorno bipolar

    Directory of Open Access Journals (Sweden)

    Alda Martin

    1999-01-01

    Full Text Available Os resultados de estudos de famílias sugerem que o transtorno bipolar tenha uma base genética. Essa hipótese foi reforçada em estudos de adoção e de gêmeos. A herança do transtorno bipolar é complexa, envolve vários genes, além de apresentar heterogeneidade e interação entre fatores genéticos e não-genéticos. Achados, que já foram replicados, já implicaram os cromossomos 4, 12, 18 e 21, entre outros, na busca por genes de suscetibilidade. Os resultados mais promissores foram obtidos através de estudos de ligação. Por outro lado, os estudos de associação geraram dados interessantes, mas ainda vagos. Os estudos de populações de pacientes homogêneos e a melhor definição do fenótipo deverão contribuir para avanços futuros. A identificação dos genes relacionados ao transtorno bipolar irá permitir o melhor entendimento e tratamento dessa doença.

  8. Exploring channeling optimized radiofrequency energy: a review of radiofrequency history and applications in esthetic fields.

    Science.gov (United States)

    Belenky, Inna; Margulis, Ariel; Elman, Monica; Bar-Yosef, Udi; Paun, Silviu D

    2012-03-01

    Because of its high efficiency and safety, radiofrequency (RF) energy is widely used in the dermatological field for heating biological tissue in various esthetic applications, including skin tightening, skin lifting, body contouring, and cellulite reduction. This paper reviews the literature on the use of nonablative RF energy in the esthetic field and its scientific background. The purpose of this article is to describe in detail the extensive use of medical devices based on RF technology, the development of these medical devices over the years, and recent developments and trends in RF technology. The authors conducted a systematic search of publications that address safety and efficacy issues, technical system specifications, and clinical techniques. Finally, the authors focused on their own clinical experiences with the use of patented Channeling Optimized RF Energy technique and mechanical massage. An in-vivo study was conducted in domestic pigs, with a thermal video camera. Twenty-seven female patients participated in a cellulite and body shaping study. The treatments were conducted according to a three-phase protocol. An additional 16 females participated in a skin tightening case study. All of the patients underwent three treatment sessions at 3-week intervals, each according to a protocol specific to the area being treated. The review of the literature on RF-based systems revealed that these systems are safe, with low risks for potential side effects, and effective for cellulite, body contouring, and skin tightening procedures. The in-vivo measurements confirmed the theory that the penetration depth of RF is an inverse function of its frequency, and using a vacuum mechanism makes an additional contribution to the RF energy penetration. The heating effect of RF was also found to increase blood circulation and to induce collagen remodeling. The results from the cellulite and body shaping treatments showed an overall average improvement of 55% in the

  9. A survey on monopolar radiofrequency treatment.

    Science.gov (United States)

    Suh, Dong Hye; Hong, Eun Sun; Kim, Hyun Joo; Lee, Sang Jun; Kim, Hei Sung

    2017-09-01

    This questionnaire-based study was aimed to measure the level of appreciation, awareness of the special tips, and practice patterns of monopolar radiofrequency among Korean dermatologists practicing a specific monopolar radiofrequency device (Thermage® Inc., Hayward, CA). A total of 82 surveys were analyzed to show that the majority of participants (78.8%) were highly satisfied with the outcomes of monopolar radiofrequency treatment. All respondents were aware of the Eye Tip 0.25 cm 2 , and the majority knew the difference between the Face tip (blue) and the Total tip (orange). Most (86.3%) agreed to the statement that 900 shots were appropriate for facial tightening in those between the ages of 35 and 65 years. 66.2% of participants reported to have perform monopolar radiofrequency to extra-facial sites within the past year. As for the tips, the Total tip was most popular for all body sties and the Big tip was favored for the abdomen, thighs and buttock. We hope our data allow dermatologists to better utilize monopolar radiofrequency. © 2017 Wiley Periodicals, Inc.

  10. Radiofrequency ablation in dermatology

    Directory of Open Access Journals (Sweden)

    Sachdeva Silonie

    2007-01-01

    Full Text Available Radiofreqeuency ablation is a versatile dermatosurgical procedure used for surgical management of skin lesions by using various forms of alternating current at an ultra high frequency. The major modalities in radiofrequency are electrosection, electrocoagulation, electrodessication and fulguration. The use of radiofrequency ablation in dermatosurgical practice has gained importance in recent years as it can be used to treat most of the skin lesions with ease in less time with clean surgical field due to adequate hemostasis and with minimal side effects and complications. This article focuses on the major tissue effects and factors influencing radiofrequency ablation and its application for various dermatological conditions.

  11. RADIOFREQUENCY SUPERCONDUCTIVITY: Workshop

    International Nuclear Information System (INIS)

    Lengeler, Herbert

    1989-01-01

    Superconducting radiofrequency is already playing an important role in the beam acceleration system for the TRISTAN electron-positron collider at the Japanese KEK Laboratory and new such systems are being prepared for other major machines. Thus the fourth Workshop on Radiofrequency Superconductivity, organized by KEK under the chairmanship of local specialist Yuzo Kojima and held just before the International Conference on High Energy Accelerators, had much progress to review and even more to look forward to

  12. Circuit engineering principles for construction of bipolar large-scale integrated circuit storage devices and very large-scale main memory

    Science.gov (United States)

    Neklyudov, A. A.; Savenkov, V. N.; Sergeyez, A. G.

    1984-06-01

    Memories are improved by increasing speed or the memory volume on a single chip. The most effective means for increasing speeds in bipolar memories are current control circuits with the lowest extraction times for a specific power consumption (1/4 pJ/bit). The control current circuitry involves multistage current switches and circuits accelerating transient processes in storage elements and links. Circuit principles for the design of bipolar memories with maximum speeds for an assigned minimum of circuit topology are analyzed. Two main classes of storage with current control are considered: the ECL type and super-integrated injection type storage with data capacities of N = 1/4 and N 4/16, respectively. The circuits reduce logic voltage differentials and the volumes of lexical and discharge buses and control circuit buses. The limiting speed is determined by the antiinterference requirements of the memory in storage and extraction modes.

  13. A New Radiofrequency Ablation Procedure to Treat Sacroiliac Joint Pain.

    Science.gov (United States)

    Cheng, Jianguo; Chen, See Loong; Zimmerman, Nicole; Dalton, Jarrod E; LaSalle, Garret; Rosenquist, Richard

    2016-01-01

    Low back pain may arise from disorders of the sacroiliac joint in up to 30% of patients. Radiofrequency ablation (RFA) of the nerves innervating the sacroiliac joint has been shown to be a safe and efficacious strategy. We aimed to develop a new RFA technique to relieve low back pain secondary to sacroiliac joint disorders. Methodology development with validation through prospective observational non-randomized trial (PONRT). Academic multidisciplinary health care system, Ohio, USA. We devised a guide-block to facilitate accurate placement of multiple electrodes to simultaneously ablate the L5 dorsal ramus and lateral branches of the S1, S2, and S3 dorsal rami. This was achieved by bipolar radiofrequency ablation (b-RFA) to create a strip lesion from the lateral border of the base of the sacral superior articular process (L5-S1 facet joint) to the lateral border of the S3 sacral foramen. We applied this technique in 31 consecutive patients and compared the operating time, x-ray exposure time and dose, and clinical outcomes with patients (n = 62) who have been treated with the cooled radiofrequency technique. Patients' level of pain relief was reported as 80% pain relief at one, 3, 6, and 12 months after the procedure. The relationship between RFA technique and duration of pain relief was evaluated using interval-censored multivariable Cox regression. The new technique allowed reduction of operating time by more than 50%, x-ray exposure time and dose by more than 80%, and cost by more than $1,000 per case. The percent of patients who achieved > 50% pain reduction was significantly higher in the b-RFA group at 3, 6, and 12 months follow-up, compared to the cooled radiofrequency group. No complications were observed in either group. Although the major confounding factors were taken into account in the analysis, use of historical controls does not balance observed and unobserved potential confounding variables between groups so that the reported results are potentially

  14. Bipolar disorder in adolescence.

    Science.gov (United States)

    DeFilippis, Melissa; Wagner, Karen Dineen

    2013-08-01

    Bipolar disorder is a serious psychiatric condition that may have onset in childhood. It is important for physicians to recognize the symptoms of bipolar disorder in children and adolescents in order to accurately diagnose this illness early in its course. Evidence regarding the efficacy of various treatments is necessary to guide the management of bipolar disorder in youth. For example, several medications commonly used for adults with bipolar disorder have not shown efficacy for children and adolescents with bipolar disorder. This article reviews the prevalence, diagnosis, course, and treatment of bipolar disorder in children and adolescents and provides physicians with information that will aid in diagnosis and treatment.

  15. Radiofrequency ablation of osteoid osteoma

    NARCIS (Netherlands)

    Vanderschueren, Geert Maria Joris Michael

    2009-01-01

    The main purpose of this thesis was to evaluate the effectiveness and safety of CT-guided radiofrequency ablation for the treatment of spinal and non-spinal osteoid osteomas. Furthermore, the technical requirements needed for safe radiofrequency ablation and the clinical outcome after radiofrequency

  16. Short time efficacy and safety of focused monopolar radiofrequency device for labial laxity improvement-noninvasive labia tissue tightening. A prospective cohort study.

    Science.gov (United States)

    Fistonić, Ivan; Sorta Bilajac Turina, Iva; Fistonić, Nikola; Marton, Ingrid

    2016-03-01

    To evaluate safety and efficacy of focused monopolar radio frequency (RF) device for non-invasive labia tissue tightening and improvement of labial laxity. This prospective cohort study participants were 17 female subjects aged between 27 and 56 years with lax skin at the labia area. All subjects received four consecutive treatments at 7-day intervals with RF device (Exilis Protege IntimaR, BTL Industries Inc., Boston, MA). The primary efficacy outcome measure was defined as one or more point improvement on 1-4 scale for vulva appearance determined by three blinded evaluators. Digital photographs were taken at the baseline and 1 month after the last treatment. Sexual gratification was assessed with Female Sexual Functioning Index (FSFI) and patient discomfort by Visual Analogue Scale (VAS). An average 2.9 (of maximum 4) points improvement rate in vulvar appearance was observed (P RF device for non-invasive labia tissue tightening. The treatment is effective and safe with high patient satisfaction. © 2016 Wiley Periodicals, Inc.

  17. Cytokines in bipolar disorder

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Vinberg, Maj; Vedel Kessing, Lars

    2012-01-01

    BACKGROUND: Current research and hypothesis regarding the pathophysiology of bipolar disorder suggests the involvement of immune system dysfunction that is possibly related to disease activity. Our objective was to systematically review evidence of cytokine alterations in bipolar disorder according...... to affective state. METHODS: We conducted a systemtic review of studies measuring endogenous cytokine concentrations in patients with bipolar disorder and a meta-analysis, reporting results according to the PRISMA statement. RESULTS: Thirteen studies were included, comprising 556 bipolar disorder patients...

  18. 21 CFR 880.6300 - Implantable radiofrequency transponder system for patient identification and health information.

    Science.gov (United States)

    2010-04-01

    ... patient identification and health information. 880.6300 Section 880.6300 Food and Drugs FOOD AND DRUG... radiofrequency transponder system for patient identification and health information. (a) Identification. An implantable radiofrequency transponder system for patient identification and health information is a device...

  19. Electronic monitoring in bipolar disorder.

    Science.gov (United States)

    Faurholt-Jepsen, Maria

    2018-03-01

    Major reasons for the insufficient effects of current treatment options in bipolar disorder include delayed intervention for prodromal depressive and manic symptoms and decreased adherence to psychopharmacological treatment. The reliance on subjective information and clinical evaluations when diagnosing and assessing the severity of depressive and manic symptoms calls for less biased and more objective markers. By using electronic devices, fine-grained data on complex psychopathological aspects of bipolar disorder can be evaluated unobtrusively over the long term. Moreover, electronic data could possibly represent candidate markers of diagnosis and illness activity in bipolar disorder and allow for early and individualized intervention for prodromal symptoms outside clinical settings. 
The present dissertation concerns the use of electronic monitoring as a marker and treatment intervention in bipolar disorder and investigated the scientific literature and body of evidence within the area, which includes ten original study reports and two systematic reviews, one of which included a meta-analysis, conducted by the author of the dissertation. 
Taken together, the literature presented in this dissertation illustrates that 1) smartphone-based electronic self-monitoring of mood seems to reflect clinically assessed depressive and manic symptoms and enables the long-term characterization of mood

instability in bipolar disorder; 2) preliminary results suggest that smartphone-based automatically generated data (e.g. the number of text messages sent/day; the number of incoming and outgoing calls/day; the number of changes in cell tower IDs/day; and voice features) seem to reflect clinically assessed depressive and manic symptoms in bipolar disorder; 3) smartphone-based electronic self-monitoring had no effects on the severity of depressive and manic symptoms in bipolar disorder, according to a randomized controlled trial; and 4) electronic monitoring of psychomotor

  20. Nutrition and Bipolar Depression.

    Science.gov (United States)

    Beyer, John L; Payne, Martha E

    2016-03-01

    As with physical conditions, bipolar disorder is likely to be impacted by diet and nutrition. Patients with bipolar disorder have been noted to have relatively unhealthy diets, which may in part be the reason they also have an elevated risk of metabolic syndrome and obesity. An improvement in the quality of the diet should improve a bipolar patient's overall health risk profile, but it may also improve their psychiatric outcomes. New insights into biological dysfunctions that may be present in bipolar disorder have presented new theoretic frameworks for understanding the relationship between diet and bipolar disorder. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

    International Nuclear Information System (INIS)

    Anfinsen, Ole-Gunnar

    1999-01-01

    The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks related to

  2. Radiofrequency catheter ablation: A study concerning electrode configuration, lesion size and potential complications

    Energy Technology Data Exchange (ETDEWEB)

    Anfinsen, Ole-Gunnar

    1999-07-01

    The study was performed to evaluate different methods of increasing the lesion size in radiofrequency catheter ablation, which is an important issue as the clinical indications for RF ablation are extended. The safety aspects of RF ablation are also studied, both with standard catheters and with experimental ones. The studies have been performed in vitro, in an animal model and in patients. The results are presented in 5 papers with titles of: 1) 'Radiofrequency catheter ablation of procine right atrium: Increased lesion size with bipolar two-catheter technique compared to unipolar application in vitro and in vivo. 2) Bipolar radiofrequency catheter ablation creates confluent lesions at a larger interelectrode spacing than does unipolar ablation from two electrodes in porcine heart. 3) Temperature-controlled radiofrequency catheter ablation with a 10 mm tip electrode creates larger lesions without charring in the porcine heart. 4) Radiofrequency catheter ablation in vitro: The difference between tissue and catheter tip temperature depends on location of the temperature sensor. 5) The activation of platelet function, coagulation and fibrinolysis during radiofrequency catheter ablation in heparin zed patients. The main conclusions are: 1) Large RF lesions may be created either by using larger electrodes and more power in the unipolar mode, or by changing the electrode configuration and thereby the geometry of the electrical field during RF current delivery. Both the 10 mm unipolar, the dielectrode and the bipolar mode showed feasible in porcine IVC-TV isthmus and right atrial free wall ablations, but the gain in lesion length was most pronounced in the bipolar mode. 2) Crater formation and intramural haemorrhages may complicate RF ablation using high current density in the right atrial free wall. In our study this was observed with 10 mm unipolar and bipolar two-catheter ablation. Phrenic nerve injury and lesions of the adjacent pulmonary tissue are risks

  3. Radiofrequency for the treatment of skin laxity: mith or truth*

    Science.gov (United States)

    de Araújo, Angélica Rodrigues; Soares, Viviane Pinheiro Campos; da Silva, Fernanda Souza; Moreira, Tatiane da Silva

    2015-01-01

    The nonablative radiofrequency is a procedure commonly used for the treatment of skin laxity from an increase in tissue temperature. The goal is to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue. However, many of these devices haven't been tested and their parameters are still not accepted by the scientific community. Because of this, it is necessary to review the literature regarding the physiological effects and parameters for application of radiofrequency and methodological quality and level of evidence of studies. A literature search was performed in MEDLINE, PEDro, SciELO, PubMed, LILACS and CAPES and experimental studies in humans, which used radiofrequency devices as treatment for facial or body laxity, were selected. The results showed that the main physiological effect is to stimulate collagen synthesis. There was no homogeneity between studies in relation to most of the parameters used and the methodological quality of studies and level of evidence for using radiofrequency are low. This fact complicates the determination of effective parameters for clinical use of this device in the treatment of skin laxity. The analyzed studies suggest that radiofrequency is effective, however the physiological mechanisms and the required parameters are not clear in the literature. PMID:26560216

  4. Enhanced Performance of Bipolar Cascade Light Emitting Diodes by Doping the Aluminum Oxide Apertures

    National Research Council Canada - National Science Library

    Siskaninetz, William

    2004-01-01

    Performance improvements in multiple-stage, single-cavity bipolar cascade light emitting diodes including reduced operating voltages, enhanced light generation, and reduced device heating are obtained...

  5. A novel method for real-time skin impedance measurement during radiofrequency skin tightening treatments.

    Science.gov (United States)

    Harth, Yoram; Lischinsky, Daniel

    2011-03-01

    The thermal effects of monopolar and bipolar radiofrequency (RF) have been proven to be beneficial in skin tightening. Nevertheless, these effects were frequently partial or unpredictable because of the uncontrolled nature of monopolar or unipolar RF and the superficial nature of energy flow for bipolar or tripolar configurations. One of the hypotheses for lack or predictability of efficacy of the first-generation RF therapy skin tightening systems is lack of adaptation of delivered power to differences in individual skin impedance. A novel multisource phase-controlled system was used (1 MHz, power range 0-65 W) for treatment and real-time skin impedance measurements in 24 patients (EndyMed PRO™; EndyMed, Cesarea, Israel). This system allows continuous real-time measurement of skin impedance delivering constant energy to the patient skin independent of changes in its impedance. More than 6000 unique skin impedance measurements on 22 patients showed an average session impedance range was 215-584 Ohm with an average of 369 Ohm (standard deviation of 49 Ohm). Analyzing individual pulses (total of 600 readings) showed a significant decrease in impedance during the pulse. These findings validate the expected differences in skin impedance between individual patients and in the same patients during the treatment pulse. Clinical study on 30 patients with facial skin aging using the device has shown high predictability of efficacy (86.7% of patients had good results or better at 3 months' follow-up [decrease of 2 or more grades in Fitzpatrick's wrinkle scale]). The real-time customization of energy according to skin impedance allows a significantly more accurate and safe method of nonablative skin tightening with more consistent and predictable results. © 2011 Wiley Periodicals, Inc.

  6. Bipolar soft connected, bipolar soft disconnected and bipolar soft compact spaces

    Directory of Open Access Journals (Sweden)

    Muhammad Shabir

    2017-06-01

    Full Text Available Bipolar soft topological spaces are mathematical expressions to estimate interpretation of data frameworks. Bipolar soft theory considers the core features of data granules. Bipolarity is important to distinguish between positive information which is guaranteed to be possible and negative information which is forbidden or surely false. Connectedness and compactness are the most important fundamental topological properties. These properties highlight the main features of topological spaces and distinguish one topology from another. Taking this into account, we explore the bipolar soft connectedness, bipolar soft disconnectedness and bipolar soft compactness properties for bipolar soft topological spaces. Moreover, we introduce the notion of bipolar soft disjoint sets, bipolar soft separation, and bipolar soft hereditary property and study on bipolar soft connected and disconnected spaces. By giving the detailed picture of bipolar soft connected and disconnected spaces we investigate bipolar soft compact spaces and derive some results related to this concept.

  7. Fast beam radiofrequency spectroscopy

    International Nuclear Information System (INIS)

    Pipkin, F.M.

    1983-01-01

    The combination of a fast atom or ion beam derived from a small accelerator with radiofrequency spectroscopy methods provides a powerful method for measuring the fine structure of atomic and molecular systems. The fast beam makes possible measurements in which two separated oscillatory fields are used to obtain resonance lines whose widths are less than the natural line width due to the lifetimes of the states. The separated oscillatory field lines have, in addition, a number of features which make possible measurements with greater precision and less sensitivity to systematic errors. The fast beam also makes accessible multiple photon radiofrequency transitions whose line width is intrinsically narrower than that of the single photon transitions and which offer great potential for high precision measurements. This report focuses on the techniques and their promise. Recent measurements of the fine structure of H and He + are used as illustrations

  8. WORKSHOP: Radiofrequency superconductivity

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1984-10-15

    The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators.

  9. WORKSHOP: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Anon.

    1984-01-01

    The Second Workshop on Radiofrequency Superconductivity was held at CERN from 23-27 July, four years after the first, organized at Karlsruhe. 35 invited talks were presented to the about 80 participants from Australia, Brazil, Europe, Japan and the United States. For the first time, ten Laboratories operating or planning superconducting accelerators for heavy ions participated and shared their experience with the community proposing the use of superconducting accelerating sections for electron accelerators

  10. Genetics Home Reference: bipolar disorder

    Science.gov (United States)

    ... Email Facebook Twitter Home Health Conditions Bipolar disorder Bipolar disorder Printable PDF Open All Close All Enable Javascript to view the expand/collapse boxes. Description Bipolar disorder is a mental health condition that causes extreme ...

  11. BIPOLAR DISORDER: A REVIEW

    OpenAIRE

    Pathan Dilnawaz N; Ziyaurrahaman A.R; Bhise K.S.

    2010-01-01

    Bipolar disorder (BD) is a severe psychiatric disorder that results in poor global functioning, reduced quality of life and high relapse rates. Research finds that many adults with bipolar disorder identify the onset of symptoms in childhood and adolescence, indicating the importance of early accurate diagnosis and treatment. Accurate diagnosis of mood disorders is critical for treatment to be effective. Distinguishing between major depression and bipolar disorders, especially the depressed p...

  12. Bipolar magnetic semiconductor in silicene nanoribbons

    International Nuclear Information System (INIS)

    Farghadan, Rouhollah

    2017-01-01

    Highlights: • A new electronic phase for silicene nanoribbon in the presence of electric and magnetic fields. • Bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps in silicene. • Robust bipolar magnetic semiconductor features in a rough silicene. • Perfect and reversible spin polarization in silicene nanoribbon junctions. - Abstract: A theoretical study was presented on generation of spin polarization in silicene nanoribbons using the single-band tight-binding approximation and the non-equilibrium Green’s function formalism. We focused on the effect of electric and exchange magnetic fields on the spin-filter capabilities of zigzag-edge silicene nanoribbons in the presence of the intrinsic spin-orbit interaction. The results show that a robust bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps can be obtained when exchange magnetic and electric field strengths are both larger than the intrinsic spin-orbit interaction. Therefore, zigzag silicene nanoribbons could act as bipolar and perfect spin filter devices with a large spin-polarized current and a reversible spin polarization in the vicinity of the Fermi energy. We also investigated the effect of edge roughness and found that the bipolar magnetic semiconductor features are robust against edge disorder in silicene nanoribbon junctions. These results may be useful in multifunctional spin devices based on silicene nanoribbons.

  13. Bipolar magnetic semiconductor in silicene nanoribbons

    Energy Technology Data Exchange (ETDEWEB)

    Farghadan, Rouhollah, E-mail: rfarghadan@kashanu.ac.ir

    2017-08-01

    Highlights: • A new electronic phase for silicene nanoribbon in the presence of electric and magnetic fields. • Bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps in silicene. • Robust bipolar magnetic semiconductor features in a rough silicene. • Perfect and reversible spin polarization in silicene nanoribbon junctions. - Abstract: A theoretical study was presented on generation of spin polarization in silicene nanoribbons using the single-band tight-binding approximation and the non-equilibrium Green’s function formalism. We focused on the effect of electric and exchange magnetic fields on the spin-filter capabilities of zigzag-edge silicene nanoribbons in the presence of the intrinsic spin-orbit interaction. The results show that a robust bipolar magnetic semiconductor with controllable spin-flip and spin-conserved gaps can be obtained when exchange magnetic and electric field strengths are both larger than the intrinsic spin-orbit interaction. Therefore, zigzag silicene nanoribbons could act as bipolar and perfect spin filter devices with a large spin-polarized current and a reversible spin polarization in the vicinity of the Fermi energy. We also investigated the effect of edge roughness and found that the bipolar magnetic semiconductor features are robust against edge disorder in silicene nanoribbon junctions. These results may be useful in multifunctional spin devices based on silicene nanoribbons.

  14. Bipolar Disorder in Women

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2013-06-01

    Full Text Available The research on gender's role in bipolar disorders has drawn significant interest recently. The presentation and course of bipolar disorder differs between women and men. Women experience depressive episodes, dysphoric mood, mixed states, rapid cycling and seasonal patterns more often than men. Comorbidity, particularly thyroid disease, migraine, obesity, and anxiety disorders laso occur more frequently in women than men. On the other hand men with bipolar disorder are also more likely than women to have problems with drug or alcohol abuse. The pregnancy and postpartum period is a time of high risk for onset and recurrence of bipolar disorder in women.

  15. Split-face histological and biochemical evaluation of tightening efficacy using temperature- and impedance-controlled continuous non-invasive radiofrequency energy.

    Science.gov (United States)

    Boisnic, Sylvie; Divaris, Marc; Branchet, Marie-Christine; Nelson, Andrew A

    2017-06-01

    Bipolar radiofrequency (RF) is capable of heating dermal collagen fibers and inducing skin tightening by collagen remodeling. To substantiate safety and improvement of skin laxity following skin heating with a novel temperature- and impedance-controlled non-invasive radiofrequency (RF) device by histological and biochemical evaluations. A split-face study was performed on 4 subjects who underwent 8 weekly RF sessions on one side of their face, leaving the other side an untreated control and then underwent facelift procedure. Clinical evaluation by photographs was done prior to the surgical procedure. Ex vivo fragments were harvested from both sides and compared. Morphometric analysis of dermal collagen fibers, collagen synthesis, and elastin synthesis evaluations were compared in triplicates. Facial skin tightening was apparent in split-face photographs. A significant increase of 7.9% in dermal collagen content, and a significant increase of 34.7% in collagen synthesis were demonstrated in the treated samples. No statistically significant effect on elastin synthesis was detected. Skin tightening following treatment with non-invasive RF has proven histologically and biochemically to derive from increase in dermal collagen synthesis and content.

  16. Radiofrequency sensory ablation as a treatment for symptomatic unilateral lumbosacral junction pseudarticulation (Bertolotti's syndrome): a case report.

    Science.gov (United States)

    Burnham, Robert

    2010-06-01

    Describe the clinical presentation, diagnostic evaluation, and successful treatment of a case of symptomatic unilateral lumbosacral junction pseudarticulation using a novel radiofrequency nerve ablation technique. A 56-year-old female patient who had suffered with low back and right upper buttock pain for 16 years experienced incomplete relief with L4/5 facet joint radiofrequency ablation. She was found to have an elongated right L5 transverse process that articulated with the sacral ala (Bertolotti's syndrome). Fluoroscopically guided local anesthetic/corticosteroid injection into the pseudarthrosis eliminated her residual right buttock pain for the duration of the local anesthetic only. Complete pain relief was achieved by injecting local anesthetic circumferentially around the posterior pseudarthrosis articular margin. Accordingly, bipolar radiofrequency strip thermal lesions were created at the same locations. Complete pain relief and full restoration of function was achieved for 16 months postprocedure. This case report describes a novel radiofrequency technique for treating symptomatic lumbosacral junction pseudarticulation that warrants further evaluation.

  17. Radiofrequency in cosmetic dermatology.

    Science.gov (United States)

    Beasley, Karen L; Weiss, Robert A

    2014-01-01

    The demand for noninvasive methods of facial and body rejuvenation has experienced exponential growth over the last decade. There is a particular interest in safe and effective ways to decrease skin laxity and smooth irregular body contours and texture without downtime. These noninvasive treatments are being sought after because less time for recovery means less time lost from work and social endeavors. Radiofrequency (RF) treatments are traditionally titrated to be nonablative and are optimal for those wishing to avoid recovery time. Not only is there minimal recovery but also a high level of safety with aesthetic RF treatments. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. International radiofrequency standards

    International Nuclear Information System (INIS)

    Lincoln, J.

    2001-01-01

    Of the various radiofrequency standards in use around the world, many are based on or similar to the Guidelines published by ICNIRP (The International Commission on Non-ionising Radiation Protection). This organisation is a working group operating in co-operation with the Environmental Health division of the World Health Organisation (WHO). This paper presents a very brief overview of current international standards, beginning with a summary of the salient points of the ICNIRP Guidelines. It should be remembered that these are guidelines only and do not exist as a separate standard. Copyright (2001) Australasian Radiation Protection Society Inc

  19. Sacroiliac joint pain: Prospective, randomised, experimental and comparative study of thermal radiofrequency with sacroiliac joint block.

    Science.gov (United States)

    Cánovas Martínez, L; Orduña Valls, J; Paramés Mosquera, E; Lamelas Rodríguez, L; Rojas Gil, S; Domínguez García, M

    2016-05-01

    To compare the analgesic effects between the blockade and bipolar thermal radiofrequency in the treatment of sacroiliac joint pain. Prospective, randomised and experimental study conducted on 60 patients selected in the two hospitals over a period of nine months, who had intense sacroiliac joint pain (Visual Analogue Scale [VAS]>6) that lasted more than 3 months. Patients were randomised into three groups (n=20): Group A (two intra-articular sacroiliac injections of local anaesthetic/corticosteroid guided by ultrasound in 7 days). Group B: conventional bipolar radiofrequency "palisade". Target points were the lateral branch nerves of S1, S2, and S3, distance needles 1cm. Group C: modified bipolar radiofrequency "palisade" (needle distance >1cm). Patients were evaluated at one month, three months, and one year. Demographic data, VAS reduction, and side effects of the techniques were assessed. One month after the treatment, pain reduction was >50% in the three groups PDolor. Publicado por Elsevier España, S.L.U. All rights reserved.

  20. Comparative familial aggregation of bipolar disorder in patients with bipolar I and bipolar II disorders.

    Science.gov (United States)

    Parker, Gordon B; Romano, Mia; Graham, Rebecca K; Ricciardi, Tahlia

    2018-05-01

    We sought to quantify the prevalence and differential prevalence of a bipolar disorder among family members of patients with a bipolar I or II disorder. The sample comprised 1165 bipolar and 1041 unipolar patients, with the former then sub-typed as having either a bipolar I or II condition. Family history data was obtained via an online self-report tool. Prevalence of a family member having a bipolar disorder (of either sub-type) was distinctive (36.8%). Patients with a bipolar I disorder reported a slightly higher family history (41.2%) compared to patients with a bipolar II disorder (36.3%), and with both significantly higher than the rate of bipolar disorder in family members of unipolar depressed patients (18.5%). Findings support the view that bipolar disorder is heritable. The comparable rates in the two bipolar sub-types support the positioning of bipolar II disorder as a valid condition with strong genetic underpinnings.

  1. Ion transport Modeling in a Bipolar Membrane

    International Nuclear Information System (INIS)

    Kim, Jung Soo; Park, Kwang Heon; Kim, Kwang Wook

    2010-01-01

    The COL(Carbonate-based Oxidative Leaching) process is an environmentally-friendly technique for collecting only uranium from spent fuel with oxidation leaching/ precipitation of carbonate solution. The bipolar membrane used for the electrolyte circulation of the salt used in the COL process is a special form of ion exchange membrane which combines CEM(cation exchange membrane) and AEM(anion exchange membrane). After arranging positive ion exchange layer toward negative terminal and positive ion exchange layer toward positive terminal, then supply electricity, water molecules are decomposed into protons and hydroxyl ions by a strong electric field in the transition region inside bipolar membrane.1) In this study, a theoretical approach to increase the efficiency of Na + and NO3 - ion collecting device using bipolar membrane was taken and simulating using the COMSOL program was tried. The details of results are also discussed

  2. Properties of Bipolar Fuzzy Hypergraphs

    OpenAIRE

    Akram, M.; Dudek, W. A.; Sarwar, S.

    2013-01-01

    In this article, we apply the concept of bipolar fuzzy sets to hypergraphs and investigate some properties of bipolar fuzzy hypergraphs. We introduce the notion of $A-$ tempered bipolar fuzzy hypergraphs and present some of their properties. We also present application examples of bipolar fuzzy hypergraphs.

  3. Visualizing radiofrequency-skin interaction using multiphoton microscopy in vivo.

    Science.gov (United States)

    Tsai, Tsung-Hua; Lin, Sung-Jan; Lee, Woan-Ruoh; Wang, Chun-Chin; Hsu, Chih-Ting; Chu, Thomas; Dong, Chen-Yuan

    2012-02-01

    Redundant skin laxity is a major feature of aging. Recently, radiofrequency has been introduced for nonablative tissue tightening by volumetric heating of the deep dermis. Despite the wide range of application based on this therapy, the effect of this technique on tissue and the subsequent tissue remodeling have not been investigated in detail. Our objective is to evaluate the potential of non-linear optics, including multiphoton autofluorescence and second harmonic generation (SHG) microscopy, as a non-invasive imaging modality for the real-time study of radiofrequency-tissue interaction. Electro-optical synergy device (ELOS) was used as the radiofrequency source in this study. The back skin of nude mouse was irradiated with radiofrequency at different passes. We evaluated the effect on skin immediately and 1 month after treatment with multiphoton microscopy. Corresponding histology was performed for comparison. We found that SHG is negatively correlated to radiofrequency passes, which means that collagen structural disruption happens immediately after thermal damage. After 1 month of collagen remodeling, SHG signals increased above baseline, indicating that collagen regeneration has occurred. Our findings may explain mechanism of nonablative skin tightening and were supported by histological examinations. Our work showed that monitoring the dermal heating status of RF and following up the detailed process of tissue reaction can be imaged and quantified with multiphoton microscopy non-invasively in vivo. Copyright © 2011. Published by Elsevier Ireland Ltd.

  4. Bipolar Disorder in Children

    Science.gov (United States)

    2014-01-01

    Although bipolar disorder historically was thought to only occur rarely in children and adolescents, there has been a significant increase in children and adolescents who are receiving this diagnosis more recently (Carlson, 2005). Nonetheless, the applicability of the current bipolar disorder diagnostic criteria for children, particularly preschool children, remains unclear, even though much work has been focused on this area. As a result, more work needs to be done to further the understanding of bipolar symptoms in children. It is hoped that this paper can assist psychologists and other health service providers in gleaning a snapshot of the literature in this area so that they can gain an understanding of the diagnostic criteria and other behaviors that may be relevant and be informed about potential approaches for assessment and treatment with children who meet bipolar disorder criteria. First, the history of bipolar symptoms and current diagnostic criteria will be discussed. Next, assessment strategies that may prove helpful for identifying bipolar disorder will be discussed. Then, treatments that may have relevance to children and their families will be discussed. Finally, conclusions regarding work with children who may have a bipolar disorder diagnosis will be offered. PMID:24800202

  5. Radiofrequency attenuator and method

    Science.gov (United States)

    Warner, Benjamin P [Los Alamos, NM; McCleskey, T Mark [Los Alamos, NM; Burrell, Anthony K [Los Alamos, NM; Agrawal, Anoop [Tucson, AZ; Hall, Simon B [Palmerston North, NZ

    2009-01-20

    Radiofrequency attenuator and method. The attenuator includes a pair of transparent windows. A chamber between the windows is filled with molten salt. Preferred molten salts include quarternary ammonium cations and fluorine-containing anions such as tetrafluoroborate (BF.sub.4.sup.-), hexafluorophosphate (PF.sub.6.sup.-), hexafluoroarsenate (AsF.sub.6.sup.-), trifluoromethylsulfonate (CF.sub.3SO.sub.3.sup.-), bis(trifluoromethylsulfonyl)imide ((CF.sub.3SO.sub.2).sub.2N.sup.-), bis(perfluoroethylsulfonyl)imide ((CF.sub.3CF.sub.2SO.sub.2).sub.2N.sup.-) and tris(trifluoromethylsulfonyl)methide ((CF.sub.3SO.sub.2).sub.3C.sup.-). Radicals or radical cations may be added to or electrochemically generated in the molten salt to enhance the RF attenuation.

  6. Electromagnetic field sources in radiofrequency

    International Nuclear Information System (INIS)

    Oliveira, C.; Sebastiao, D.; Ladeira, D.; Antunes, M.; Correia, L.M.

    2010-01-01

    In the scope of the monIT Project, several measurements were made of electromagnetic fields in Portugal. This paper presents an analysis of the sources operating in the radiofrequency range, resulting from 2429 measurements in 466 locations.

  7. What is Bipolar Disorder?

    Science.gov (United States)

    ... down” Have trouble sleeping Think about death or suicide Can someone have bipolar disorder along with other problems? Yes. Sometimes people having very strong mood episodes may have psychotic symptoms. Psychosis affects thoughts ...

  8. Bipolar resistive switching in different plant and animal proteins

    KAUST Repository

    Bag, A.; Hota, Mrinal Kanti; Mallik, Sandipan B.; Maì ti, Chinmay Kumar

    2014-01-01

    We report bipolar resistive switching phenomena observed in different types of plant and animal proteins. Using protein as the switching medium, resistive switching devices have been fabricated with conducting indium tin oxide (ITO) and Al as bottom and top electrodes, respectively. A clockwise bipolar resistive switching phenomenon is observed in all proteins. It is shown that the resistive switching phenomena originate from the local redox process in the protein and the ion exchange from the top electrode/protein interface.

  9. Bipolar resistive switching in different plant and animal proteins

    KAUST Repository

    Bag, A.

    2014-06-01

    We report bipolar resistive switching phenomena observed in different types of plant and animal proteins. Using protein as the switching medium, resistive switching devices have been fabricated with conducting indium tin oxide (ITO) and Al as bottom and top electrodes, respectively. A clockwise bipolar resistive switching phenomenon is observed in all proteins. It is shown that the resistive switching phenomena originate from the local redox process in the protein and the ion exchange from the top electrode/protein interface.

  10. Characterization of tracked radiofrequency ablation in phantom

    International Nuclear Information System (INIS)

    Chen, Chun-Cheng R.; Miga, Michael I.; Galloway, Robert L.

    2007-01-01

    In radiofrequency ablation (RFA), successful therapy requires accurate, image-guided placement of the ablation device in a location selected by a predictive treatment plan. Current planning methods rely on geometric models of ablations that are not sensitive to underlying physical processes in RFA. Implementing plans based on computational models of RFA with image-guided techniques, however, has not been well characterized. To study the use of computational models of RFA in planning needle placement, this work compared ablations performed with an optically tracked RFA device with corresponding models of the ablations. The calibration of the tracked device allowed the positions of distal features of the device, particularly the tips of the needle electrodes, to be determined to within 1.4±0.6 mm of uncertainty. Ablations were then performed using the tracked device in a phantom system based on an agarose-albumin mixture. Images of the sliced phantom obtained from the ablation experiments were then compared with the predictions of a bioheat transfer model of RFA, which used the positional data of the tracked device obtained during ablation. The model was demonstrated to predict 90% of imaged pixels classified as being ablated. The discrepancies between model predictions and observations were analyzed and attributed to needle tracking inaccuracy as well as to uncertainties in model parameters. The results suggest the feasibility of using finite element modeling to plan ablations with predictable outcomes when implemented using tracked RFA

  11. Ion energy distributions in bipolar pulsed-dc discharges of methane measured at the biased cathode

    Energy Technology Data Exchange (ETDEWEB)

    Corbella, C; Rubio-Roy, M; Bertran, E; Portal, S; Pascual, E; Polo, M C; Andujar, J L, E-mail: corbella@ub.edu [FEMAN Group, IN2UB, Departament de Fisica Aplicada i Optica, Universitat de Barcelona, c/ MartI i Franques 1, 08028 Barcelona (Spain)

    2011-02-15

    The ion fluxes and ion energy distributions (IED) corresponding to discharges in methane (CH{sub 4}) were measured in time-averaged mode with a compact retarding field energy analyser (RFEA). The RFEA was placed on a biased electrode at room temperature, which was powered by either radiofrequency (13.56 MHz) or asymmetric bipolar pulsed-dc (250 kHz) signals. The shape of the resulting IED showed the relevant populations of ions bombarding the cathode at discharge parameters typical in the material processing technology: working pressures ranging from 1 to 10 Pa and cathode bias voltages between 100 and 200 V. High-energy peaks in the IED were detected at low pressures, whereas low-energy populations became progressively dominant at higher pressures. This effect is attributed to the transition from collisionless to collisional regimes of the cathode sheath as the pressure increases. On the other hand, pulsed-dc plasmas showed broader IED than RF discharges. This fact is connected to the different working frequencies and the intense peak voltages (up to 450 V) driven by the pulsed power supply. This work improves our understanding in plasma processes at the cathode level, which are of crucial importance for the growth and processing of materials requiring controlled ion bombardment. Examples of industrial applications with these requirements are plasma cleaning, ion etching processes during fabrication of microelectronic devices and plasma-enhanced chemical vapour deposition of hard coatings (diamond-like carbon, carbides and nitrides).

  12. The Biological Effects of Quadripolar Radiofrequency Sequential Application: A Human Experimental Study

    OpenAIRE

    Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

    2014-01-01

    Objective: An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Background data: Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. Methods: The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radio...

  13. Measurement of radiofrequency fields

    International Nuclear Information System (INIS)

    Leonowich, J.A.

    1992-05-01

    We are literally surrounded by radiofrequency (RFR) and microwave radiation, from both natural and man-made sources. The identification and control of man-made sources of RFR has become a high priority of radiation safety professionals in recent years. For the purposes of this paper, we will consider RFR to cover the frequencies from 3 kHz to 300 MHz, and microwaves from 300 MHz to 300 GHz, and will use the term RFR interchangeably to describe both. Electromagnetic radiation and field below 3 kHz is considered Extremely Low Frequency (ELF) and will not be discussed in this paper. Unlike x- and gamma radiation, RFR is non-ionizing. The energy of any RFR photon is insufficient to produce ionizations in matter. The measurement and control of RFR hazards is therefore fundamentally different from ionizing radiation. The purpose of this paper is to acquaint the reader with the fundamental issues involved in measuring and safely using RFR fields. 23 refs

  14. Bipolar Affective Disorder and Migraine

    Directory of Open Access Journals (Sweden)

    Birk Engmann

    2012-01-01

    Full Text Available This paper consists of a case history and an overview of the relationship, aetiology, and treatment of comorbid bipolar disorder migraine patients. A MEDLINE literature search was used. Terms for the search were bipolar disorder bipolar depression, mania, migraine, mood stabilizer. Bipolar disorder and migraine cooccur at a relatively high rate. Bipolar II patients seem to have a higher risk of comorbid migraine than bipolar I patients have. The literature on the common roots of migraine and bipolar disorder, including both genetic and neuropathological approaches, is broadly discussed. Moreover, bipolar disorder and migraine are often combined with a variety of other affective disorders, and, furthermore, behavioural factors also play a role in the origin and course of the diseases. Approach to treatment options is also difficult. Several papers point out possible remedies, for example, valproate, topiramate, which acts on both diseases, but no first-choice treatments have been agreed upon yet.

  15. Depression and Bipolar Support Alliance

    Science.gov (United States)

    Depression and Bipolar Support Alliance Crisis Hotline Information Coping with a Crisis Suicide Prevention Information Psychiatric Hospitalization ... sign-up Education info, training, events Mood Disorders Depression Bipolar Disorder Anxiety Screening Center Co-occurring Illnesses/ ...

  16. Bipolar Disorder and Cancer

    Directory of Open Access Journals (Sweden)

    Sermin Kesebir

    2012-06-01

    Full Text Available Prevalence studies and studies on causation relations have shown that the relation between psychiatric disorders and chronic physical diseases is neglected. For heterogeneous diseases an increasing number of susceptibility variants are being defined. Alzheimer disease, bipolar disorder, breast and prostate cancer, coronary artery disease, Chron's disease, systemic lupus eritematosus, type 1 and type 2 diabetes mellitus are mentioned together with epigenetic concept. In acrocentric zone of chromosome 13, breast cancer, retinoblastoma, chronic Iymphocytic leukemia genes with B cells, dopamin loci of bipolar disorder are found together. Among bipolar and healthy individuals, an increase risk of breast cancer in female cases has been resported. On the other hand, psychosocial factors that affect stress and response to stress itself may be important variables in prognosis and progression of different cancer types. During the course of many cancer types –especially brain tumors- and during treatment of chemotherapeutic agents, bipolar symptomatology may appear. In this article, it is reviewed with relevant literature that whether an etiological relation between bipolar disorder and cancer exist and how both diseases affect each other's course and treatment.

  17. Use of radiofrequency in cosmetic dermatology: focus on nonablative treatment of acne scars

    Directory of Open Access Journals (Sweden)

    Simmons BJ

    2014-12-01

    Full Text Available Brian J Simmons, Robert D Griffith, Leyre A Falto-Aizpurua, Keyvan Nouri Department of Dermatology and Cutaneous Surgery, University of Miami Miller School of Medicine, University of Miami, Miami, FL, USA Abstract: Acne is a common affliction among many teens and some adults that usually resolves over time. However, the severe sequela of acne scarring can lead to long-term psychological and psychiatric problems. There exists a multitude of modalities to treat acne scars such as more invasive surgical techniques, subcision, chemical peels, ablative lasers, fractional lasers, etc. A more recent technique for the treatment of acne scars is nonablative radiofrequency (RF that works by passing a current through the dermis at a preset depth to produce small thermal wounds in the dermis which, in turn, stimulates dermal remodeling to produce new collagen and soften scar defects. This review article demonstrates that out of all RF modalities, microneedle bipolar RF and fractional bipolar RF treatments offers the best results for acne scarring. An improvement of 25%–75% can be expected after three to four treatment sessions using one to two passes per session. Treatment results are optimal approximately 3 months after final treatment. Common side effects can include transient pain, erythema, and scabbing. Further studies are needed to determine what RF treatment modalities work best for specific scar subtypes, so that further optimization of RF treatments for acne scars can be determined. Keywords: acne scarring, radiofrequency treatments, nonablative radiofrequency treatments, scars

  18. The biological effects of quadripolar radiofrequency sequential application: a human experimental study.

    Science.gov (United States)

    Nicoletti, Giovanni; Cornaglia, Antonia Icaro; Faga, Angela; Scevola, Silvia

    2014-10-01

    An experimental study was conducted to assess the effectiveness and safety of an innovative quadripolar variable electrode configuration radiofrequency device with objective measurements in an ex vivo and in vivo human experimental model. Nonablative radiofrequency applications are well-established anti-ageing procedures for cosmetic skin tightening. The study was performed in two steps: ex vivo and in vivo assessments. In the ex vivo assessments the radiofrequency applications were performed on human full-thickness skin and subcutaneous tissue specimens harvested during surgery for body contouring. In the in vivo assessments the applications were performed on two volunteer patients scheduled for body contouring surgery at the end of the study. The assessment methods were: clinical examination and medical photography, temperature measurement with thermal imaging scan, and light microscopy histological examination. The ex vivo assessments allowed for identification of the effective safety range for human application. The in vivo assessments allowed for demonstration of the biological effects of sequential radiofrequency applications. After a course of radiofrequency applications, the collagen fibers underwent an immediate heat-induced rearrangement and were partially denaturated and progressively metabolized by the macrophages. An overall thickening and spatial rearrangement was appreciated both in the collagen and elastic fibers, the latter displaying a juvenile reticular pattern. A late onset in the macrophage activation after sequential radiofrequency applications was appreciated. Our data confirm the effectiveness of sequential radiofrequency applications in obtaining attenuation of the skin wrinkles by an overall skin tightening.

  19. RADIO-FREQUENCY MASS SPECTROMETERS AND THEIR APPLICATIONS IN SPACE

    Energy Technology Data Exchange (ETDEWEB)

    Gilmour, Jr., A. S.

    1963-08-15

    The operation of three common radio-frequency mass spectrometers is described, and their performances are compared. Their limitations are pointed out. It is concluded that the quadrupole spectrometer has fewer limitations and is more generally useful in space probes than the other devices. Some present and proposed uses of spectrometers in space are discussed, and the problem of contamination of the atmosphere being sampled by the spectrometer is reviewed. (auth)

  20. Predicting burst pressure of radiofrequency-induced colorectal anastomosis by bio-impedance measurement.

    Science.gov (United States)

    Zhao, Lingxi; Zhou, Yu; Song, Chengli; Wang, Zhigang; Cuschieri, Alfred

    2017-03-01

    The present study investigates the relationship between bio-impedance and burst pressure of colorectal anastomosis created by radiofrequency (RF)-induced tissue fusion. Colorectal anastomosis were created with ex vivo porcine colorectal segments, during which 5 levels of compression pressure were applied by a custom-made bipolar prototype, with 5 replicate experiments at each compression pressure. Instant anastomotic tensile strength was assessed by burst pressure. Bio-impedance of fused tissue was measured by Impedance Analyzer across frequency that 100 Hz to 3 MHz. Statistical analysis shows only a weak correlation between bio-impedance modulus and burst pressures at frequency of 445 kHz ([Formula: see text]  =  -0.426, P  =  0.099  >  0.05). In contrast, results demonstrated a highly significant negative correlation between reactance modulus and burst pressures ([Formula: see text]  =  -0.812, P  =  0.000  <  0.05). The decrease in mean reactance modulus with increasing burst pressures was highly significant (P  =  0.019  <  0.05). The observed strong negative correlation between reactance modulus and burst pressures at frequency of 445 kHz indicates that reactance is likely to be a good index for tensile strength of RF-induced colorectal anastomosis, and should be considered for inclusion in a feedback loops in devices design.

  1. Does bipolar electrocoagulation time affect vessel weld strength?

    Science.gov (United States)

    Harrison, J D; Morris, D L

    1991-01-01

    The value of the bipolar electrocoagulator in the haemostasis of bleeding ulcers is controversial. We have therefore investigated the effect of different coagulation times on vessel weld strength achieved by the bipolar device. Welds were then made in vessels of known diameter using a standard 10F endoscopic haemostatic probe at coagulation times of two and 20 seconds. The intravascular temperature achieved at each time was measured. Vessel weld strength achieved by bipolar electrocoagulation was much greater at 20 seconds (approximately twice that at two seconds) and was highly significantly greater at all vessel diameters. There was a gradual reduction in weld strength with increasing vessel diameter, an effect that was seen for both two and 20 seconds of electrocoagulation. Intravascular temperature was significantly higher at 20 seconds than at two seconds. We conclude that vessel weld strength is related to coagulation time and that any future studies comparing the bipolar electrocoagulator with other haemostatic devices should use longer periods of bipolar electrocoagulation and record the coagulation time in order to optimise the clinical value of the device. PMID:1864540

  2. Types of Bipolar Disorder

    Science.gov (United States)

    ... Events Home Science News Meetings and Events Multimedia Social Media Press Resources Newsletters NIMH News Feeds About Us ... has a lot of money, or has special powers. Someone having psychotic symptoms ... Substance Abuse: People with bipolar disorder may also misuse alcohol ...

  3. Discrete bipolar universal integrals

    Czech Academy of Sciences Publication Activity Database

    Greco, S.; Mesiar, Radko; Rindone, F.

    2014-01-01

    Roč. 252, č. 1 (2014), s. 55-65 ISSN 0165-0114 R&D Projects: GA ČR GAP402/11/0378 Institutional support: RVO:67985556 Keywords : bipolar integral * universal integral * Choquet integral Subject RIV: BA - General Mathematics Impact factor: 1.986, year: 2014 http://library.utia.cas.cz/separaty/2014/E/mesiar-0432224.pdf

  4. El trastorno bipolar

    OpenAIRE

    Freaza Rodríguez, Paula

    2014-01-01

    Se exponen los aspectos más relevantes del trastorno bipolar, entender qué significa este concepto, conocer los tipos que existen, qué otros trastornos suelen aparecer al mismo tiempo y qué tratamientos son los que dan mejores resultados

  5. Thermosonic wire bonding of IC devices using palladium wire

    International Nuclear Information System (INIS)

    Shze, J.H.; Poh, M.T.; Tan, R.M.

    1996-01-01

    The feasibility of replacing gold wire by palladium wire in thermosonic wire bonding of CMOS and bipolar devices are studied in terms of the manufacturability, physical, electrical and assembly performance. The results that palladium wire is a viable option for bonding the bipolar devices but not the CMOS devices

  6. Radiofrequency fields in our surroundings

    International Nuclear Information System (INIS)

    2011-01-01

    In 2010, the National Radiation Protection Authority (NRPA) with the Post and Telecommunications Authority carried out a project where it is measured radiofrequency fields from various telecom systems in homes, kindergartens, schools, offices, and urban environments. Close to 99 percent of the measurement points were found values of less than one thousandth of the maximum. No values were near the limits. (AG)

  7. ON BIPOLAR SINGLE VALUED NEUTROSOPHIC GRAPHS

    OpenAIRE

    Said Broumi; Mohamed Talea; Assia Bakali; Florentin Smarandache

    2016-01-01

    In this article, we combine the concept of bipolar neutrosophic set and graph theory. We introduce the notions of bipolar single valued neutrosophic graphs, strong bipolar single valued neutrosophic graphs, complete bipolar single valued neutrosophic graphs, regular bipolar single valued neutrosophic graphs and investigate some of their related properties.

  8. Treatment of Décolletage Photoaging With Fractional Microneedling Radiofrequency.

    Science.gov (United States)

    Lyons, Alexis; Roy, Jillian; Herrmann, Jennifer; Chipps, Lisa

    2018-01-01

    The objective of this study was to examine the efficacy and safety of a novel fractional microneedling radiofrequency device to improve the appearance of rhytides and skin laxity of the décolletage. Twelve subjects received a total of three fractional microneedling radiofrequency treatments with Endymed Intensif (EndyMed Ltd., Cesarea, Israel) at least three weeks apart. Primary outcome measure was clinical efficacy quantified by a patient survey to assess treatment satisfaction as well as a physician Global Aesthetic Improvement Scale (GAIS). Photos were taken before every treatment and at a follow-up appointment. Assessments by two board-certified dermatologists revealed an overall improvement in 67% of patients. Seventy percent of subjects rated their post-treatment skin laxity and rhytides as improved, while 60% of patients rated their skin texture as improved. Eighty percent of subjects were at least slightly satisfied with their treatment. Forty percent of subjects would recommend this treatment to others. Subjects in this study demonstrated an overall improvement in décolletage appearance in regard to skin tightening, wrinkles, and skin texture suggested by overall patient satisfaction (80%) and physician-rated GAIS improvement (67%). This study suggests that fractional microneedling radiofrequency devices are a safe and efficacious way to improve overall décolletage appearance with little down time. J Drugs Dermatol. 2018;17(1):74-76..

  9. WORKSHOP: Radiofrequency superconductivity

    International Nuclear Information System (INIS)

    Tückmantel, Joachim

    1993-01-01

    Full text: With superconducting radiofrequency playing a major role in the push for new machines to break fresh physics frontiers, it has become a tradition for experts and newcomers in this field from all over the world to meet every second year to hear progress reports from laboratories and to discuss common problems and possible solutions. The sixth such workshop was held from 4-8 October under the chairmanship of Ron Sundelin at the Continuous Electron Beam Accelerator Facility (CEBAF) under construction in Newport News, Virginia. With 170 participants from 14 countries including Eastern Europe and China, it reflected the growing interest in the field - looking back to 1984, when CERN was the host laboratory, the second workshop had less than 100 participants. The CEBAF meeting began with laboratory status reports, covering both high beam energy ('high beta') applications with 'spherical' cavities (as with CERN's LEP200), all using niobium as superconductor and working between 352 MHz and 3 GHz, and lower energy (low beta') applications with geometrically more complicated shapes such as quarter or half wave, split ring or spoke resonators, some using electrodeposited lead as superconductor and working around 100 MHz. During these talks it became clear that more and more laboratories have focused on routine problems, such as reliable series production and testing, running cavities with ancillaries in the machines, or building complete prototypes for projects to be approved by critical funding authorities. This contrasts with the heady days just a few years ago when - at least in the high beta community - the main objective was to explore new ideas. State-of-the-art summaries showed how at 1.3 and 3 GHz 25-30 MV/m have been reached by several laboratories using different preparation methods. Newer developments for common problems included r.f. windows, couplers, controls, and especially field emission, public enemy number one for

  10. Modelling ionising radiation induced defect generation in bipolar oxides with gated diodes

    International Nuclear Information System (INIS)

    Barnaby, H.J.; Cirba, C.; Schrimpf, R.D.; Kosier, St.; Fouillat, P.; Montagner, X.

    1999-01-01

    Radiation-induced oxide defects that degrade electrical characteristics of bipolar junction transistor (BJTs) can be measured with the use of gated diodes. The buildup of defects and their effect on device radiation response are modeled with computer simulation. (authors)

  11. Occupational exposure of NRM spectrometrists to static and radiofrequency fields

    International Nuclear Information System (INIS)

    Berlana, Tania; Ubeda, Alejandro

    2017-01-01

    Occupational exposure to static and radiofrequency fields emitted by nuclear magnetic resonance spectrometers was assessed through systematic field metering during operation of 19 devices in nine research centers. Whereas no measurable levels of radiofrequency radiation were registered outside the spectrometers, significant exposure to static field was detected, with maximum values recorded at the user s hand (B = 683.00 mT) and head thorax (B = 135.70 mT) during spectrometer manipulation. All values were well below the exposure limits set by the European standard for workers protection against the effects of acute field exposure only. As for potential effects of chronic exposure, waiting for more complete knowledge, adoption of technical and operational strategies for exposure minimizing is advisable. In this respect, the data revealed that compared with standard magnetic shielding, ultra-shield technology allows a 20-65-fold reduction of the field strength received by the operator. (authors)

  12. Life expectancy in bipolar disorder

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2015-01-01

    OBJECTIVE: Life expectancy in patients with bipolar disorder has been reported to be decreased by 11 to 20 years. These calculations are based on data for individuals at the age of 15 years. However, this may be misleading for patients with bipolar disorder in general as most patients have a later...... onset of illness. The aim of the present study was to calculate the remaining life expectancy for patients of different ages with a diagnosis of bipolar disorder. METHODS: Using nationwide registers of all inpatient and outpatient contacts to all psychiatric hospitals in Denmark from 1970 to 2012 we...... remaining life expectancy in bipolar disorder and that of the general population decreased with age, indicating that patients with bipolar disorder start losing life-years during early and mid-adulthood. CONCLUSIONS: Life expectancy in bipolar disorder is decreased substantially, but less so than previously...

  13. [Bipolar disorder in adolescence].

    Science.gov (United States)

    Brunelle, Julie; Milhet, Vanessa; Consoli, Angèle; Cohen, David

    2014-04-01

    Juvenile mania is a concept widely developed but also highly debated since the 1990s. In the heart of this debate, Severe Mood Dysregulation (SMD) and "Temper Dysregulation disorder with Dysphoria" (recently integrated in DSM-5) showed their interest. Actually, the objective is to distinguish two clinical phenotypes in order to avoid confusion between (1) what would raise more of mood dysregulation with chronic manic like symptoms, and (2) bipolar disorder type I with episodic and acute manic episodes. Therapeutic stakes are major. In adolescents, even if DSM adult diagnostic criteria can be used and bipolar disorder type I clearly established, differential diagnostic at onset between acute manic episode and schizophrenia onset remain sometimes difficult to assess. Furthermore, it is crucial to better assess outcome of these adolescents, in terms of morbidity and potential prognosis factors, knowing that a younger age at onset is associated with a poorer outcome according to several adult studies. Therapeutic implications could then be drawn.

  14. Depressive and bipolar disorders

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Hansen, Hanne Vibe; Demyttenaere, Koen

    2005-01-01

    of the patients (40-80%) had erroneous views as to the effect of antidepressants. Older patients (over 40 years of age) consistently had a more negative view of the doctor-patient relationship, more erroneous ideas concerning the effect of antidepressants and a more negative view of antidepressants in general....... Moreover, their partners agreed on these negative views. Women had a more negative view of the doctor-patient relationship than men, and patients with a depressive disorder had a more negative view of antidepressants than patients with bipolar disorder. The number of psychiatric hospitalizations......BACKGROUND: There is increasing evidence that attitudes and beliefs are important in predicting adherence to treatment and medication in depressive and bipolar disorders. However, these attitudes have received little study in patients whose disorders were sufficiently severe to require...

  15. Bipolar Plates for PEM Systems

    OpenAIRE

    Lædre, Sigrid

    2016-01-01

    Summary of thesis: The Bipolar Plate (BPP) is an important component in both Proton Exchange Membrane Fuel Cells (PEMFCs) and Proton Exchange Membrane Water Electrolyzers (PEMWEs). Bipolar plate material and processing constitutes for a large fraction of the cost and weight of a PEM cell stack. The main tasks for the bipolar plates in both systems are to separate single cell in a stack, conduct current between single cells and remove heat from active areas. In addition, the BPPs distribu...

  16. [Creativity and bipolar disorder].

    Science.gov (United States)

    Maçkalı, Zeynep; Gülöksüz, Sinan; Oral, Timuçin

    2014-01-01

    The relationship between creativity and bipolar disorder has been an intriguing topic since ancient times. Early studies focused on describing characteristics of creative people. From the last quarter of the twentieth century, researchers began to focus on the relationship between mood disorders and creativity. Initially, the studies were based on biographical texts and the obtained results indicated a relationship between these two concepts. The limitations of the retrospective studies led the researchers to develop systematic investigations into this area. The systematic studies that have focused on artistic creativity have examined both the prevalence of mood disorders and the creative process. In addition, a group of researchers addressed the relationship in terms of affective temperaments. Through the end of the 90's, the scope of creativity was widened and the notion of everyday creativity was proposed. The emergence of this notion led researchers to investigate the associations of the creative process in ordinary (non-artist) individuals. In this review, the descriptions of creativity and creative process are mentioned. Also, the creative process is addressed with regards to bipolar disorder. Then, the relationship between creativity and bipolar disorder are evaluated in terms of aforementioned studies (biographical, systematic, psychobiographical, affective temperaments). In addition, a new model, the "Shared Vulnerability Model" which was developed to explain the relationship between creativity and psychopathology is introduced. Finally, the methodological limitations and the suggestions for resolving these limitations are included.

  17. Reviewing metallic PEMFC bipolar plates

    Energy Technology Data Exchange (ETDEWEB)

    Wang, H.; Turner, J.A. [National Renewable Energy Laboratory, Golden, CO (United States)

    2010-08-15

    A bipolar plate is one of the most important components in a polymer exchange membrane fuel cell (PEMFC) stack and has multiple functions. Metallic bipolar plate candidates have advantages over composite rivals in excellent electrical and thermal conductivity, good mechanical strength, high chemical stability, very wide alloy choices, low cost and, most importantly, existing pathways for high-volume, high-speed mass production. The challenges with metallic bipolar plates are the higher contact resistance and possible corrosion products, which may contaminate the membrane electrode assembly. This review evaluates the candidate metallic and coating materials for bipolar plates and gives the perspective of the research trends. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  18. Radiofrequency Ablation of Hepatic Cysts : Case Report

    International Nuclear Information System (INIS)

    Lee, Ye Ri; Kim, Pyo Nyun

    2005-01-01

    Radiofrequency ablation has been frequently performed on intra-hepatic solid tumor, namely, hepatocellular carcinoma, metastatic tumor and cholangio carcinoma, for take the cure. But, the reports of radiofrequency ablation for intrahepatic simple cysts are few. In vitro experiment of animal and in vivo treatment for intrahepatic cysts of human had been reported in rare cases. We report 4 cases of radiofrequency ablation for symptomatic intrahepatic cysts

  19. 78 FR 21129 - Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of...

    Science.gov (United States)

    2013-04-09

    ... radiofrequency band ranging between 13 megahertz to 27.12 megahertz and is intended for the treatment of medical...] Orthopaedic and Rehabilitation Devices Panel of the Medical Devices Advisory Committee; Notice of Meeting... the public. Name of Committee: Orthopaedic and Rehabilitation Devices Panel of the Medical Devices...

  20. Superconducting Radio-Frequency Cavities

    Science.gov (United States)

    Padamsee, Hasan S.

    2014-10-01

    Superconducting cavities have been operating routinely in a variety of accelerators with a range of demanding applications. With the success of completed projects, niobium cavities have become an enabling technology, offering upgrade paths for existing facilities and pushing frontier accelerators for nuclear physics, high-energy physics, materials science, and the life sciences. With continued progress in basic understanding of radio-frequency superconductivity, the performance of cavities has steadily improved to approach theoretical capabilities.

  1. Real-time estimation of lesion depth and control of radiofrequency ablation within ex vivo animal tissues using a neural network.

    Science.gov (United States)

    Wang, Yearnchee Curtis; Chan, Terence Chee-Hung; Sahakian, Alan Varteres

    2018-01-04

    Radiofrequency ablation (RFA), a method of inducing thermal ablation (cell death), is often used to destroy tumours or potentially cancerous tissue. Current techniques for RFA estimation (electrical impedance tomography, Nakagami ultrasound, etc.) require long compute times (≥ 2 s) and measurement devices other than the RFA device. This study aims to determine if a neural network (NN) can estimate ablation lesion depth for control of bipolar RFA using complex electrical impedance - since tissue electrical conductivity varies as a function of tissue temperature - in real time using only the RFA therapy device's electrodes. Three-dimensional, cubic models comprised of beef liver, pork loin or pork belly represented target tissue. Temperature and complex electrical impedance from 72 data generation ablations in pork loin and belly were used for training the NN (403 s on Xeon processor). NN inputs were inquiry depth, starting complex impedance and current complex impedance. Training-validation-test splits were 70%-0%-30% and 80%-10%-10% (overfit test). Once the NN-estimated lesion depth for a margin reached the target lesion depth, RFA was stopped for that margin of tissue. The NN trained to 93% accuracy and an NN-integrated control ablated tissue to within 1.0 mm of the target lesion depth on average. Full 15-mm depth maps were calculated in 0.2 s on a single-core ARMv7 processor. The results show that a NN could make lesion depth estimations in real-time using less in situ devices than current techniques. With the NN-based technique, physicians could deliver quicker and more precise ablation therapy.

  2. Radiofrequency (RF) radiation measurement for diathermy machine

    International Nuclear Information System (INIS)

    Rozaimah Abdul Rahim; Roha Tukimin; Mohd Amirul Nizam; Ahmad Fadzli; Mohd Azizi

    2010-01-01

    Full-text: Diathermy machine is one of medical device that use widely in hospital and clinic. During the diathermy treatment, high radiofrequency (RF) currents (shortwave and microwave) are used to heat deep muscular tissues through electromagnetic energy to body tissues. The heat increases blood flow, relieve pain and speeding up recovery. The stray RF radiation from the machine can exposes to unintended tissue of the patient, to the operator (physical therapist) and also can cause electromagnetic interference (EMI) effect to medical devices around the machine. The main objective of this study is to establish a database of the RF radiation exposure levels experienced by the operator and patient during the treatments. RF radiation (electric and magnetic field) produced by the diathermy machines were measured using special RF survey meters. The finding of this study confirms that radiation levels on the surface and near the applicator of the diathermy machine much more elevated due to the much closer distance to the source and they exceeding the occupational and general public exposure limit. The results also shows the field strengths drop very significantly when the distance of measurement increase. (author)

  3. Radiofrequency facial rejuvenation: evidence-based effect.

    Science.gov (United States)

    el-Domyati, Moetaz; el-Ammawi, Tarek S; Medhat, Walid; Moawad, Osama; Brennan, Donna; Mahoney, My G; Uitto, Jouni

    2011-03-01

    Multiple therapies involving ablative and nonablative techniques have been developed for rejuvenation of photodamaged skin. Monopolar radiofrequency (RF) is emerging as a gentler, nonablative skin-tightening device that delivers uniform heat to the dermis at a controlled depth. We evaluated the clinical effects and objectively quantified the histologic changes of the nonablative RF device in the treatment of photoaging. Six individuals of Fitzpatrick skin type III to IV and Glogau class I to II wrinkles were subjected to 3 months of treatment (6 sessions at 2-week intervals). Standard photographs and skin biopsy specimens were obtained at baseline, and at 3 and 6 months after the start of treatment. We performed quantitative evaluation of total elastin, collagen types I and III, and newly synthesized collagen using computerized histometric and immunohistochemical techniques. Blinded photographs were independently scored for wrinkle improvement. RF produced noticeable clinical results, with high satisfaction and corresponding facial skin improvement. Compared with the baseline, there was a statistically significant increase in the mean of collagen types I and III, and newly synthesized collagen, while the mean of total elastin was significantly decreased, at the end of treatment and 3 months posttreatment. A limitation of this study is the small number of patients, yet the results show a significant improvement. Although the results may not be as impressive as those obtained by ablative treatments, RF is a promising treatment option for photoaging with fewer side effects and downtime. Copyright © 2010 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  4. High-performance silicon nanowire bipolar phototransistors

    Science.gov (United States)

    Tan, Siew Li; Zhao, Xingyan; Chen, Kaixiang; Crozier, Kenneth B.; Dan, Yaping

    2016-07-01

    Silicon nanowires (SiNWs) have emerged as sensitive absorbing materials for photodetection at wavelengths ranging from ultraviolet (UV) to the near infrared. Most of the reports on SiNW photodetectors are based on photoconductor, photodiode, or field-effect transistor device structures. These SiNW devices each have their own advantages and trade-offs in optical gain, response time, operating voltage, and dark current noise. Here, we report on the experimental realization of single SiNW bipolar phototransistors on silicon-on-insulator substrates. Our SiNW devices are based on bipolar transistor structures with an optically injected base region and are fabricated using CMOS-compatible processes. The experimentally measured optoelectronic characteristics of the SiNW phototransistors are in good agreement with simulation results. The SiNW phototransistors exhibit significantly enhanced response to UV and visible light, compared with typical Si p-i-n photodiodes. The near infrared responsivities of the SiNW phototransistors are comparable to those of Si avalanche photodiodes but are achieved at much lower operating voltages. Compared with other reported SiNW photodetectors as well as conventional bulk Si photodiodes and phototransistors, the SiNW phototransistors in this work demonstrate the combined advantages of high gain, high photoresponse, low dark current, and low operating voltage.

  5. Dose Rate Effects in Linear Bipolar Transistors

    Science.gov (United States)

    Johnston, Allan; Swimm, Randall; Harris, R. D.; Thorbourn, Dennis

    2011-01-01

    Dose rate effects are examined in linear bipolar transistors at high and low dose rates. At high dose rates, approximately 50% of the damage anneals at room temperature, even though these devices exhibit enhanced damage at low dose rate. The unexpected recovery of a significant fraction of the damage after tests at high dose rate requires changes in existing test standards. Tests at low temperature with a one-second radiation pulse width show that damage continues to increase for more than 3000 seconds afterward, consistent with predictions of the CTRW model for oxides with a thickness of 700 nm.

  6. One-year results of the use of endovenous radiofrequency ablation utilising an optimised radiofrequency-induced thermotherapy protocol for the treatment of truncal superficial venous reflux.

    Science.gov (United States)

    Badham, George E; Dos Santos, Scott J; Lloyd, Lucinda Ba; Holdstock, Judy M; Whiteley, Mark S

    2018-06-01

    Background In previous in vitro and ex vivo studies, we have shown increased thermal spread can be achieved with radiofrequency-induced thermotherapy when using a low power and slower, discontinuous pullback. We aimed to determine the clinical success rate of radiofrequency-induced thermotherapy using this optimised protocol for the treatment of superficial venous reflux in truncal veins. Methods Sixty-three patients were treated with radiofrequency-induced thermotherapy using the optimised protocol and were followed up after one year (mean 16.3 months). Thirty-five patients returned for audit, giving a response rate of 56%. Duplex ultrasonography was employed to check for truncal reflux and compared to initial scans. Results In the 35 patients studied, there were 48 legs, with 64 truncal veins treated by radiofrequency-induced thermotherapy (34 great saphenous, 15 small saphenous and 15 anterior accessory saphenous veins). One year post-treatment, complete closure of all previously refluxing truncal veins was demonstrated on ultrasound, giving a success rate of 100%. Conclusions Using a previously reported optimised, low power/slow pullback radiofrequency-induced thermotherapy protocol, we have shown it is possible to achieve a 100% ablation at one year. This compares favourably with results reported at one year post-procedure using the high power/fast pullback protocols that are currently recommended for this device.

  7. Fluoroscopic-guided radiofrequency ablation of the basivertebral nerve: application and analysis with multiple imaging modalities in an ovine model (Invited Paper)

    Science.gov (United States)

    Bergeron, Jeffrey A.; Eskey, Cliff J.; Attawia, Mohammed; Patel, Samit J.; Ryan, Thomas P.; Pellegrino, Richard; Sutton, Jeffrey; Crombie, John; Paul, B. T.; Hoopes, P. J.

    2005-04-01

    Pathologic involvement of the basivertebral nerve, an intraosseous vertebral nerve found in humans and most mammalian species, may play a role in some forms of back pain. This study was designed to assess the feasibility and effects of the percutaneous delivery of radiofrequency (RF) energy to thermally ablate the basivertebral nerve in the lumbar vertebrae of mature sheep. Using fluoroscopic guidance, a RF bipolar device was placed and a thermal dose delivered to lumbar vertebral bodies in sheep. Post-treatment assessment included multiple magnetic resonance imaging (MRI) techniques and computed tomography (CT). These data were analyzed and correlated to histopathology and morphometry findings to describe the cellular and boney structural changes resulting from the treatment. Imaging modalities MRI and CT can be implemented to non-invasively describe treatment region and volume, marrow cellular effects, and bone density alterations immediately following RF treatment and during convalescence. Such imaging can be utilized to assess treatment effects and refine the thermal dose to vertebral body volume ratio used in treatment planning. This information will be used to improve the therapeutic ratio and develop a treatment protocol for human applications.

  8. Bipolar one diode-one resistor integration for high-density resistive memory applications.

    Science.gov (United States)

    Li, Yingtao; Lv, Hangbing; Liu, Qi; Long, Shibing; Wang, Ming; Xie, Hongwei; Zhang, Kangwei; Huo, Zongliang; Liu, Ming

    2013-06-07

    Different from conventional unipolar-type 1D-1R RRAM devices, a bipolar-type 1D-1R memory device concept is proposed and successfully demonstrated by the integration of Ni/TiOx/Ti diode and Pt/HfO2/Cu bipolar RRAM cell to suppress the undesired sneak current in a cross-point array. The bipolar 1D-1R memory device not only achieves self-compliance resistive switching characteristics by the reverse bias current of the Ni/TiOx/Ti diode, but also exhibits excellent bipolar resistive switching characteristics such as uniform switching, satisfactory data retention, and excellent scalability, which give it high potentiality for high-density integrated nonvolatile memory applications.

  9. Scientific attitudes towards bipolar disorders

    Directory of Open Access Journals (Sweden)

    Mohammad-Hossein Biglu

    2014-02-01

    Full Text Available Introduction: Bipolar disorder is a psychiatric condition that is also called manic-depressive disease. It causes unusual changes in mood, energy, activity levels, and the ability to carry out day-to-day tasks. In the present study, 3 sets of data were considered and analyzed: first, all papers categorized under Bipolar Disorders in Science Citation Index Expanded (SCI-E database through 2001-2011; second, papers published by the international journal of Bipolar Disorders indexed in SCI-E during a period of 11 years; and third, all papers distributed by the international journal of Bipolar Disorders indexed in MEDLINE during the period of study. Methods: The SCI-E database was used to extract all papers indexed with the topic of Bipolar Disorders as well as all papers published by The International Journal of Bipolar Disorders. Extraction of data from MEDLINE was restricted to the journals name from setting menu. The Science of Science Tool was used to map the co-authorship network of papers published by The International Journal of Bipolar Disorders through 2009-2011. Results: Analysis of data showed that the majority of publications in the subject area of bipolar disorders indexed in SCI-E were published by The International Journal of Bipolar Disorders. Although journal articles consisted of 59% of the total publication type in SCI-E, 65% of publications distributed by The Journal of Bipolar Disorders were in the form of meetingabstracts. Journal articles consisted of only 23% of the total publications. USA was the leading country regarding sharing data in the field of bipolar disorders followed by England, Canada, and Germany. Conclusion: The editorial policy of The International Journal of Bipolar Disorders has been focused on new themes and new ways of researching in the subject area of bipolar disorder. Regarding the selection of papers for indexing, the SCI-E database selects data more comprehensively than MEDLINE. The number of papers

  10. Epidemiology in Pediatric Bipolar Disorder

    Directory of Open Access Journals (Sweden)

    Caner Mutlu

    2015-12-01

    Full Text Available Childhood and adolescent bipolar disorder diagnosis has been increasing recently. Since studies evaluating attempted suicide rates in children and adolescents have shown bipolarity to be a significant risk factor, diagnosis and treatment of bipolarity has become a very important issue. Since there is a lack of specific diagnostic criteria for especially preadolescent samples and evaluations are made mostly symptomatically, suspicions about false true diagnosis and increased prevalence rates have emerged. This situation leads to controversial data about the prevalence rates of bipolar disorder in children and adolescents. The aim of this article is to review the prevalence of childhood and adolescent bipolar disorder in community, inpatient and outpatient based samples in literature.

  11. Genetics of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Kerner B

    2014-02-01

    Full Text Available Berit Kerner Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, CA, USA Abstract: Bipolar disorder is a common, complex genetic disorder, but the mode of transmission remains to be discovered. Many researchers assume that common genomic variants carry some risk for manifesting the disease. The research community has celebrated the first genome-wide significant associations between common single nucleotide polymorphisms (SNPs and bipolar disorder. Currently, attempts are under way to translate these findings into clinical practice, genetic counseling, and predictive testing. However, some experts remain cautious. After all, common variants explain only a very small percentage of the genetic risk, and functional consequences of the discovered SNPs are inconclusive. Furthermore, the associated SNPs are not disease specific, and the majority of individuals with a “risk” allele are healthy. On the other hand, population-based genome-wide studies in psychiatric disorders have rediscovered rare structural variants and mutations in genes, which were previously known to cause genetic syndromes and monogenic Mendelian disorders. In many Mendelian syndromes, psychiatric symptoms are prevalent. Although these conditions do not fit the classic description of any specific psychiatric disorder, they often show nonspecific psychiatric symptoms that cross diagnostic boundaries, including intellectual disability, behavioral abnormalities, mood disorders, anxiety disorders, attention deficit, impulse control deficit, and psychosis. Although testing for chromosomal disorders and monogenic Mendelian disorders is well established, testing for common variants is still controversial. The standard concept of genetic testing includes at least three broad criteria that need to be fulfilled before new genetic tests should be introduced: analytical validity, clinical validity, and clinical utility. These criteria are

  12. Electromagnetic Fields, Pulsed Radiofrequency Radiation, and Epigenetics: How Wireless Technologies May Affect Childhood Development

    Science.gov (United States)

    Sage, Cindy; Burgio, Ernesto

    2018-01-01

    Mobile phones and other wireless devices that produce electromagnetic fields (EMF) and pulsed radiofrequency radiation (RFR) are widely documented to cause potentially harmful health impacts that can be detrimental to young people. New epigenetic studies are profiled in this review to account for some neurodevelopmental and neurobehavioral changes…

  13. Endoscopic release of congenital muscular torticollis with radiofrequency in teenagers.

    Science.gov (United States)

    Wang, Jun-Liang; Qi, Wei; Liu, Yu-Jie

    2018-05-03

    Congenital muscular torticollis (CMT) is due to contracture of the sternocleidomastoid muscle which may cause activity limitations of the neck, tilt of the head, craniofacial asymmetry, and deformity of the skull. The authors present their experience of arthroscopic tight fibrous band release with radiofrequency in teenagers under local anesthesia and evaluate the clinical results. A total of 69 patients who underwent arthroscopic release of CMT with radiofrequency under local anesthesia by a single surgeon could participate in this study. Before operation, surface landmarks of sternocleidomastoid muscle, bone, and neurovascular structures were marked. Local infiltrating anesthesia of the surgical region was then performed. Through a working space created by blunt dissection, the arthroscopy and radiofrequency devices were introduced. Then, the clavicular and sternal heads of the sternocleidomastoid muscle were identified and gradually transected. The patients were followed up postoperatively with Cheng's scoring system. There were 31 male patients and 38 female patients. The mean age of the patients was 16.1 years. The mean length of follow-up in this series was 36.7 months (range, 28 to 67 months). During the operation, 62 patients (89.9%) had no pain, 6 patients (8.7%) felt mild pain, and only 1 patient (1.4%) regarded the procedure as very painful. At all follow-up periods, there were no repeat arthroscopies for any of these patients. At the final follow-up, the average rotation deficit improved from 22.5° to 4.1° postoperatively, and the average lateral bending deficit improved from 14.6° to 3.3° (p radiofrequency under local anesthesia provides surgeons with an alternative to traditional open techniques for the management of congenital muscular torticollis (CMT). Our date shows that this method is minimally invasive and provides good functional recovery with a lower risk of complications.

  14. Early Intervention in Bipolar Disorder.

    Science.gov (United States)

    Vieta, Eduard; Salagre, Estela; Grande, Iria; Carvalho, André F; Fernandes, Brisa S; Berk, Michael; Birmaher, Boris; Tohen, Mauricio; Suppes, Trisha

    2018-05-01

    Bipolar disorder is a recurrent disorder that affects more than 1% of the world population and usually has its onset during youth. Its chronic course is associated with high rates of morbidity and mortality, making bipolar disorder one of the main causes of disability among young and working-age people. The implementation of early intervention strategies may help to change the outcome of the illness and avert potentially irreversible harm to patients with bipolar disorder, as early phases may be more responsive to treatment and may need less aggressive therapies. Early intervention in bipolar disorder is gaining momentum. Current evidence emerging from longitudinal studies indicates that parental early-onset bipolar disorder is the most consistent risk factor for bipolar disorder. Longitudinal studies also indicate that a full-blown manic episode is often preceded by a variety of prodromal symptoms, particularly subsyndromal manic symptoms, therefore supporting the existence of an at-risk state in bipolar disorder that could be targeted through early intervention. There are also identifiable risk factors that influence the course of bipolar disorder, some of them potentially modifiable. Valid biomarkers or diagnosis tools to help clinicians identify individuals at high risk of conversion to bipolar disorder are still lacking, although there are some promising early results. Pending more solid evidence on the best treatment strategy in early phases of bipolar disorder, physicians should carefully weigh the risks and benefits of each intervention. Further studies will provide the evidence needed to finish shaping the concept of early intervention. AJP AT 175 Remembering Our Past As We Envision Our Future April 1925: Interpretations of Manic-Depressive Phases Earl Bond and G.E. Partridge reviewed a number of patients with manic-depressive illness in search of a unifying endo-psychic conflict. They concluded that understanding either phase of illness was "elusive" and

  15. Novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs

    OpenAIRE

    Muhammad, Akram; Musavarah, Sarwar

    2016-01-01

    In this research study, we introduce the concept of bipolar neutrosophic graphs. We present the dominating and independent sets of bipolar neutrosophic graphs. We describe novel multiple criteria decision making methods based on bipolar neutrosophic sets and bipolar neutrosophic graphs. We also develop an algorithm for computing domination in bipolar neutrosophic graphs.

  16. Reduction in adipose tissue volume using a new high-power radiofrequency technology combined with infrared light and mechanical manipulation for body contouring

    OpenAIRE

    Adatto, Maurice A.; Adatto-Neilson, Robyn M.; Morren, Grietje

    2014-01-01

    A growing patient demand for a youthful skin appearance with a favorable body shape has led to the recent development of new noninvasive body contouring techniques. We have previously demonstrated that the combination of bipolar radiofrequency (RF) and optical energies with tissue manipulation is an efficient reshaping modality. Here, we investigated the efficacy and safety of a new high-power version of this combined technology, in terms of adipose tissue reduction and skin tightening. Thirt...

  17. Hyperkalaemia after radiofrequency ablation of hepatocellular carcinoma

    NARCIS (Netherlands)

    Verhoevena, BH; Haagsma, EB; Appeltans, BMG; Slooff, MJH; de Jong, KP

    Radiofrequency ablation of liver tumours is a useful therapy for otherwise unresectable tumours. The complication rate is said to be low. In this case report we describe hyperkalaemia after radiofrequency ablation of a hepatocellular carcinoma in a patient with end-stage renal insufficiency. (C)

  18. Predicting nurses' acceptance of radiofrequency identification technology.

    Science.gov (United States)

    Norten, Adam

    2012-10-01

    The technology of radiofrequency identification allows for the scanning of radiofrequency identification-tagged objects and individuals without line-of-sight requirements. Healthcare organizations use radiofrequency identification to ensure the health and safety of patients and medical personnel and to uncover inefficiencies. Although the successful implementation of a system incorporating radiofrequency identification technologies requires acceptance and use of the technology, some nurses using radiofrequency identification in hospitals feel like "Big Brother" is watching them. This predictive study used a theoretical model assessing the effect of five independent variables: privacy concerns, attitudes, subjective norms, controllability, and self-efficacy, on a dependent variable, nurses' behavioral intention to use radiofrequency identification. A Web-based questionnaire containing previously validated questions was answered by 106 US RNs. Multiple linear regression showed that all constructs together accounted for 60% of the variance in nurses' intention to use radiofrequency identification. Of the predictors in the model, attitudes provided the largest unique contribution when the other predictors in the model were held constant; subjective norms also provided a unique contribution. Privacy concerns, controllability, and self-efficacy did not provide a significant contribution to nurses' behavioral intention to use radiofrequency identification.

  19. Time-of-Flight Positron Emission Tomography with Radiofrequency Phototube

    International Nuclear Information System (INIS)

    Margaryan, A.; Kakoyan, V.; Knyazyan, S.

    2011-01-01

    In this paper γ-detector, based on the radiofrequency (RF) phototube and recently developed fast and ultrafast scintillators, is considered for Time-of-Flight positron emission tomography applications. Timing characteristics of such a device has been investigated by means of a dedicated Monte Carlo code based on the single photon counting concept. Biexponential timing model for scintillators have been used. The calculations have shown that such a timing model is in a good agreement with recently measured data. The timing resolution of -detectors can be significantly improved by using the RF phototube. (authors)

  20. Electromagnetic induction imaging with a radio-frequency atomic magnetometer

    Energy Technology Data Exchange (ETDEWEB)

    Deans, Cameron; Marmugi, Luca, E-mail: l.marmugi@ucl.ac.uk; Hussain, Sarah; Renzoni, Ferruccio [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom)

    2016-03-07

    We report on a compact, tunable, and scalable to large arrays imaging device, based on a radio-frequency optically pumped atomic magnetometer operating in magnetic induction tomography modality. Imaging of conductive objects is performed at room temperature, in an unshielded environment and without background subtraction. Conductivity maps of target objects exhibit not only excellent performance in terms of shape reconstruction but also demonstrate detection of sub-millimetric cracks and penetration of conductive barriers. The results presented here demonstrate the potential of a future generation of imaging instruments, which combine magnetic induction tomography and the unmatched performance of atomic magnetometers.

  1. Bipolar pulse forming line

    Science.gov (United States)

    Rhodes, Mark A.

    2008-10-21

    A bipolar pulse forming transmission line module for linear induction accelerators having first, second, third, fourth, and fifth planar conductors which form an interleaved stack with dielectric layers between the conductors. Each conductor has a first end, and a second end adjacent an acceleration axis. The first and second planar conductors are connected to each other at the second ends, the fourth and fifth planar conductors are connected to each other at the second ends, and the first and fifth planar conductors are connected to each other at the first ends via a shorting plate adjacent the first ends. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short a high voltage from the first end of the third planar conductor to the first end of the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

  2. Study on ionizing radiation effects of bipolar transistor with BPSG films

    International Nuclear Information System (INIS)

    Lu Man; Zhang Xiaoling; Xie Xuesong; Sun Jiangchao; Wang Pengpeng; Lu Changzhi; Zhang Yanxiu

    2013-01-01

    Background: Because of the damage induced by ionizing radiation, bipolar transistors in integrated voltage regulator could induce the current gain degradation and increase leakage current. This will bring serious problems to electronic system. Purpose: In order to ensure the reliability of the device work in the radiation environments, the device irradiation reinforcement technology is used. Methods: The characteristics of 60 Co γ irradiation and annealing at different temperatures in bipolar transistors and voltage regulators (JW117) with different passive films for SiO 2 +BPSG+SiO 2 and SiO 2 +SiN have been investigated. Results: The devices with BPSG film enhanced radiation tolerance significantly. Because BPSG films have better absorption for Na + in SiO 2 layer, the surface recombination rate of base region in a bipolar transistor and the excess base current have been reduced. It may be the main reason for BJT with BPSG film having a good radiation hardness. And annealing experiments at different temperatures after irradiation ensure the reliability of the devices with BPSG films. Conclusions: A method of improving the ionizing irradiation hardness of bipolar transistors is proposed. As well as the linear integrated circuits which containing bipolar transistors, an experimental basis for the anti-ionizing radiation effects of bipolar transistors is provided. (authors)

  3. Asenapine for bipolar disorder

    Directory of Open Access Journals (Sweden)

    Scheidemantel T

    2015-12-01

    Full Text Available Thomas Scheidemantel,1 Irina Korobkova,2 Soham Rej,3,4 Martha Sajatovic1,2 1University Hospitals Case Medical Center, 2Case Western Reserve University School of Medicine, Cleveland, OH, USA; 3Department of Psychiatry, University of Toronto, Toronto, ON, 4Geri PARTy Research Group, Jewish General Hospital, Montreal, QC, Canada Abstract: Asenapine (Saphris® is an atypical antipsychotic drug which has been approved by the US Food and Drug Administration for the treatment of schizophrenia in adults, as well as the treatment of acute manic or mixed episodes of bipolar I in both adult and pediatric populations. Asenapine is a tetracyclic drug with antidopaminergic and antiserotonergic activity with a unique sublingual route of administration. In this review, we examine and summarize the available literature on the safety, efficacy, and tolerability of asenapine in the treatment of bipolar disorder (BD. Data from randomized, double-blind trials comparing asenapine to placebo or olanzapine in the treatment of acute manic or mixed episodes showed asenapine to be an effective monotherapy treatment in clinical settings; asenapine outperformed placebo and showed noninferior performance to olanzapine based on improvement in the Young Mania Rating Scale scores. There are limited data available on the use of asenapine in the treatment of depressive symptoms of BD, or in the maintenance phase of BD. The available data are inconclusive, suggesting the need for more robust data from prospective trials in these clinical domains. The most commonly reported adverse effect associated with use of asenapine is somnolence. However, the somnolence associated with asenapine use did not cause significant rates of discontinuation. While asenapine was associated with weight gain when compared to placebo, it appeared to be modest when compared to other atypical antipsychotics, and its propensity to cause increases in hemoglobin A1c or serum lipid levels appeared to be

  4. Reduction in adipose tissue volume using a new high-power radiofrequency technology combined with infrared light and mechanical manipulation for body contouring.

    Science.gov (United States)

    Adatto, Maurice A; Adatto-Neilson, Robyn M; Morren, Grietje

    2014-09-01

    A growing patient demand for a youthful skin appearance with a favorable body shape has led to the recent development of new noninvasive body contouring techniques. We have previously demonstrated that the combination of bipolar radiofrequency (RF) and optical energies with tissue manipulation is an efficient reshaping modality. Here, we investigated the efficacy and safety of a new high-power version of this combined technology, in terms of adipose tissue reduction and skin tightening. Thirty-five patients received one treatment per week over 6 weeks to their abdomen/flank, buttock, or thigh areas and were followed up to 3 months post completion of the treatment protocol. This new device has an increased power in the bipolar RF, as this parameter appears to be the most important energy modality for volume reduction. Patient circumferences were measured and comparisons of baseline and post treatment outcomes were made. Diagnostic ultrasound (US) measurements were performed in 12 patients to evaluate the reduction in adipose tissue volume, and a cutometer device was used to assess improvements in skin tightening. We observed a gradual decline in patient circumferences from baseline to post six treatments. The overall body shaping effect was accompanied with improvement in skin tightening and was clearly noticeable in the comparison of the before and after treatment clinical photographs. These findings correlated with measurements of adipose tissue volume and skin firmness/elasticity using diagnostic US and cutometer, respectively. The thickness of the fat layer showed on average a 29% reduction between baseline and the 1-month follow up. The average reduction in the circumference of the abdomen/flanks, buttocks, and thighs from baseline to the 3-month follow-up was 1.4, 0.5, and 1.2 cm, respectively, and 93% of study participants demonstrated a 1-60% change in fat layer thickness. Patients subjectively described comfort and satisfaction from treatment, and 97% of

  5. Evaluation of Electrostatic Force on Bipolar Charged Electret

    International Nuclear Information System (INIS)

    Sonoda, K; Minami, K; Miwatani, N; Fujita, T; Kanda, K; Maenaka, K

    2014-01-01

    This paper presents an evaluation of an electrostatic vibration energy harvester with the bipolar charged electret. The energy harvester with the size of 13 × 12 × 1.2 mm 3 was fabricated. The output power of the bipolar charged with ±250 V harvester was 9 μW when the acceleration was 1.4 g at 352 Hz with 0.9 MΩ load resistance. The effectiveness against the velocity-damped resonant-generator (VDRG) limit was 2.5%. The electrostatic forces of the actual device with DC bias, which simulates charged electret with monopolar and bipolar were experimentally and numerically verified. We estimated the electrostatic force by measuring the vibration amplitude versus applied acceleration of the electret mass. As a result, we investigated the bipolar charged device can reduce the effect of electrostatic force as low as no bias condition. The numerical model of the energy harvester considering the electrostatic force by FEM static analysis was also established. The comparison between the numerical model and the measurement results showed a similar inclination

  6. Application of accelerated simulation method on NPN bipolar transistors of different technology

    International Nuclear Information System (INIS)

    Fei Wuxiong; Zheng Yuzhan; Wang Yiyuan; Chen Rui; Li Maoshun; Lan Bo; Cui Jiangwei; Zhao Yun; Lu Wu; Ren Diyuan; Wang Zhikuan; Yang Yonghui

    2010-01-01

    With different radiation methods, ionizing radiation response of NPN bipolar transistors of six different processes was investigated. The results show that the enhanced low dose rate sensitivity obviously exists in NPN bipolar transistors of the six kinds of processes. According to the experiment, the damage of decreasing temperature in step during irradiation is obviously greater than the result of irradiated at high dose rate. This irradiation method can perfectly simulate and conservatively evaluate low dose rate damage, which is of great significance to radiation effects research of bipolar devices. Finally, the mechanisms of the experimental phenomena were analyzed. (authors)

  7. Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip.

    Science.gov (United States)

    Wang, Jian; Shen, Hao; Fan, Li; Wu, Rui; Niu, Ben; Varghese, Leo T; Xuan, Yi; Leaird, Daniel E; Wang, Xi; Gan, Fuwan; Weiner, Andrew M; Qi, Minghao

    2015-01-12

    Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.

  8. Modeling suicide in bipolar disorders.

    Science.gov (United States)

    Malhi, Gin S; Outhred, Tim; Das, Pritha; Morris, Grace; Hamilton, Amber; Mannie, Zola

    2018-02-19

    Suicide is a multicausal human behavior, with devastating and immensely distressing consequences. Its prevalence is estimated to be 20-30 times greater in patients with bipolar disorders than in the general population. The burden of suicide and its high prevalence in bipolar disorders make it imperative that our current understanding be improved to facilitate prediction of suicide and its prevention. In this review, we provide a new perspective on the process of suicide in bipolar disorder, in the form of a novel integrated model that is derived from extant knowledge and recent evidence. A literature search of articles on suicide in bipolar disorder was conducted in recognized databases such as Scopus, PubMed, and PsycINFO using the keywords "suicide", "suicide in bipolar disorders", "suicide process", "suicide risk", "neurobiology of suicide" and "suicide models". Bibliographies of identified articles were further scrutinized for papers and book chapters of relevance. Risk factors for suicide in bipolar disorders are well described, and provide a basis for a framework of epigenetic mechanisms, moderated by neurobiological substrates, neurocognitive functioning, and social inferences within the environment. Relevant models and theories include the diathesis-stress model, the bipolar model of suicide and the ideation-to-action models, the interpersonal theory of suicide, the integrated motivational-volitional model, and the three-step theory. Together, these models provide a basis for the generation of an integrated model that illuminates the suicidal process, from ideation to action. Suicide is complex, and it is evident that a multidimensional and integrated approach is required to reduce its prevalence. The proposed model exposes and provides access to components of the suicide process that are potentially measurable and may serve as novel and specific therapeutic targets for interventions in the context of bipolar disorder. Thus, this model is useful not only

  9. Bipolar explosion models for hypernovae

    International Nuclear Information System (INIS)

    Maeda, Keiichi; Nomoto, Ken'ichi

    2003-01-01

    Bipolar explosion models for hypernovae (very energetic supernovae) are presented. These models provide a favorable situation to explain some unexpected features in observations of hypernovae, e.g., high velocity matter dominated by Fe and low velocity matter dominated by O. The overall abundance of these models gives a good fit, at least qualitatively, to abundances in extremely metal-poor stars. We suggest hypernovae be driven by bipolar jets and contribute significantly to the early Galactic chemical evolution

  10. Functional remediation for bipolar disorder

    OpenAIRE

    Martínez-Arán, Anabel, 1971-; Torrent, C.; Solé, B.; Bonnín, C.M.; Rosa, A.R.; Sánchez-Moreno, J.; Vieta i Pascual, Eduard, 1963-

    2014-01-01

    Neurocognitive impairment constitutes a core feature of bipolar illness. The main domains affected are verbal memory, attention, and executive functions. Deficits in these areas as well as difficulties to get functional remission seem to be increased associated with illness progression. Several studies have found a strong relationship between neurocognitive impairment and low functioning in bipolar disorder, as previously reported in other illnesses such as schizophrenia. Cognitive remediatio...

  11. Safety work with MRI devices in medicine

    International Nuclear Information System (INIS)

    Zivkovic, D.; Hrnjak, M.

    1999-01-01

    This paper gives the basis of biological effects of physical factors which could affect personnel working on MRI devices and patients, and corresponding protection measures. Medical personnel working with MRI devices and patients could be exposed to static magnetic field, time varying fields and radiofrequency radiation, danger from electric current and chemical matters, and there is a high risk from moving metal objects which could wound the persons near-by. The protection from static magnetic field could be ensured by increasing the distance from the source. If MRI device is put in Faradays cage it could be corresponding protection of radiofrequency radiation. (author)

  12. [Radiofrequency ablation of hepatocellular carcinoma].

    Science.gov (United States)

    Widmann, Gerlig; Schullian, Peter; Bale, Reto

    2013-03-01

    Percutaneous radiofrequency ablation (RFA) is well established in the treatment of hepatocellular carcinoma (HCC). Due to its curative potential, it is the method of choice for non resectable BCLC (Barcelona Liver Clinic) 0 and A. RFA challenges surgical resection for small HCC and is the method of choice in bridging for transplantation and recurrence after resection or transplantation. The technical feasibility of RFA depends on the size and location of the HCC and the availability of ablation techniques (one needle techniques, multi-needle techniques). More recently, stereotactic multi-needle techniques with 3D trajectory planning and guided needle placement substantially improve the spectrum of treatable lesions including large volume tumors. Treatment success depends on the realization of ablations with large intentional margins of tumor free tissue (A0 ablation in analogy to R0 resection), which has to be documented by fusion of post- with pre-ablation images, and confirmed during follow-up imaging.

  13. Quetiapine monotherapy for bipolar depression

    Directory of Open Access Journals (Sweden)

    Michael E Thase

    2008-03-01

    Full Text Available Michael E ThaseDepartments of Psychiatry, University of Pennsylvania School of Medicine, Philadelphia, PA, USA; the Philadelphia Veterans Affairs Medical Center, Philadelphia, PA, USA; and the University of Pittsburgh Medical Center, Pittsburgh, PA, USAAbstract: Bipolar depression is more common, disabling, and difficult-to-treat than the manic and hypomanic phases that define bipolar disorder. Unlike the treatment of so-called “unipolar” depressions, antidepressants generally are not indicated as monotherapies for bipolar depressions and recent studies suggest that - even when used in combination with traditional mood stabilizers – antidepressants may have questionable value for bipolar depression. The current practice is that mood stabilizers are initiated first as monotherapies; however, the antidepressant efficacy of lithium and valproate is modest at best. Within this context the role of atypical antipsychotics is being evaluated. The combination of olanzapine and the antidepressant fluoxetine was the first treatment to receive regulatory approval in the US specifically for bipolar I depression. Quetiapine was the second medication to be approved for this indication, largely as the result of two pivotal trials known by the acronyms of BOLDER (BipOLar DEpRession I and II. Both studies demonstrated that two doses of quetiapine (300 mg and 600 mg given once daily at bedtime were significantly more effective than placebo, with no increased risk of patients switching into mania. Pooling the two studies, quetiapine was effective for both bipolar I and bipolar II depressions and for patients with (and without a history of rapid cycling. The two doses were comparably effective in both studies. Although the efficacy of quetiapine monotherapy has been established, much additional research is necessary. Further studies are needed to more fully investigate dose-response relationships and comparing quetiapine monotherapy to other mood stabilizers

  14. Transport Characteristics of Mesoscopic Radio-Frequency Single Electron Transistor

    International Nuclear Information System (INIS)

    Phillips, A. H.; Kirah, K.; Aly, N. A. I.; El-Sayes, H. E.

    2008-01-01

    The transport property of a quantum dot under the influence of external time-dependent field is investigated. The mesoscopic device is modelled as semiconductor quantum dot coupled weakly to superconducting leads via asymmetric double tunnel barriers of different heights. An expression for the current is deduced by using the Landauer–Buttiker formula, taking into consideration of both the Coulomb blockade effect and the magnetic field. It is found that the periodic oscillation of the current with the magnetic field is controlled by the ratio of the frequency of the applied ac-field to the electron cyclotron frequency. Our results show that the present device operates as a radio-frequency single electron transistor

  15. Long-wave plasma radiofrequency ablation for treatment of xanthelasma palpebrarum.

    Science.gov (United States)

    Baroni, Adone

    2018-03-01

    Xanthelasma palpebrarum is the most common type of xanthoma affecting the eyelids. It is characterized by asymptomatic soft yellowish macules, papules, or plaques over the upper and lower eyelids. Many treatments are available for management of xanthelasma palpebrarum, the most commonly used include surgical excision, ablative CO 2 or erbium lasers, nonablative Q-switched Nd:YAG laser, trichloroacetic acid peeling, and radiofrequency ablation. This study aims to evaluate the effectiveness of RF ablation in the treatment of xanthelasma palpebrarum, with D.A.S. Medical portable device (Technolux, Italia), a radiofrequency tool working with long-wave plasma energy and without anesthesia. Twenty patients, 15 female and 5 male, affected by xanthelasma palpebrarum, were enrolled for long-wave plasma radiofrequency ablation treatment. The treatment consisted of 3/4 sessions that were carried out at intervals of 30 days. Treatments were well tolerated by all patients with no adverse effects and optimal aesthetic results. The procedure is very fast and can be performed without anesthesia because of the low and tolerable pain stimulation. Long-wave plasma radiofrequency ablation is an effective option for treatment of xanthelasma palpebrarum and adds an additional tool to the increasing list of medical devices for aesthetic treatments. © 2018 Wiley Periodicals, Inc.

  16. Integrated neurobiology of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Vladimir eMaletic

    2014-08-01

    Full Text Available From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity—reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition—limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional unified field theory of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial-neuronal interactions. Among these glial elements are microglia—the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the HPA axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of bipolarity is one of the great

  17. Lateral n-p-n bipolar transistors by ion implantation into semi-insulating GaAs

    International Nuclear Information System (INIS)

    Canfield, P.; Forbes, L.

    1988-01-01

    GaAs bipolar transistors have not seen the major development effort that GaAs MESFETs have due primarily to the short minority carrier lifetimes in GaAs. The short minority carrier lifetimes require that the base region be very thin which, if done by implantation, requires that the doping be high to obtain a well defined base profile. These requirements are very difficult to achieve in GaAs and typically, if high current gain and high speed are desired for a bipolar technology, then heterostructure bipolars are the appropriate technology, although the cost of heterostructure devices will be prohibitive for some time to come. For applications requiring low current gain, more modest fabrication rules can be followed. Lateral bipolars are particularly attractive since they would be easier to fabricate than a planar bipolar or a heterojunction bipolar. Lateral bipolars do not require steps or deep contacts to make contact with the subcollector or highly doped very thin epilayers for the base region and they can draw upon the semi-insulating properties of the GaAs substrates for device isolation. Bipolar transistors are described and shown to work successfully. (author)

  18. Endovascular ultrasound for renal sympathetic denervation in patients with therapy-resistant hypertension not responding to radiofrequency renal sympathetic denervation.

    Science.gov (United States)

    Stiermaier, Thomas; Okon, Thomas; Fengler, Karl; Mueller, Ulrike; Hoellriegel, Robert; Schuler, Gerhard; Desch, Steffen; Lurz, Philipp

    2016-06-12

    Recent studies have reported a considerable number of non-responders after renal sympathetic de-nervation (RSD) with radiofrequency technology. Here we report our results of repeat RSD using ultrasound in these patients. A cohort study was performed in patients who underwent ultrasound RSD after non-response to RSD with radiofrequency. Non-response was defined as mean daytime systolic blood pressure ≥140 mmHg and/or a reduction of ≤10 mmHg in ambulatory blood pressure measurement (ABPM) ≥6 months after radiofrequency denervation. ABPM was recorded at baseline, post radiofrequency RSD as well as at three and six months post ultrasound RSD. A total of 24 non-responders underwent retreatment with the ultrasound device at a mean 15.3±8.2 months after radiofrequency RSD. Ultrasound RSD was performed successfully in all patients without severe adverse events. Mean daytime systolic blood pressure changed from 161.7±14.6 mmHg at baseline to 158.5±9.5 mmHg post radiofrequency RSD and to 150.5±10.4 mmHg and 151.6±11.0 mmHg at three and six months, respectively, post ultrasound RSD (pmeasures analysis of variance). The main results of post hoc testing were as follows: baseline versus post radiofrequency RSD, p=0.83; baseline versus three months post ultrasound RSD, p=0.01; and baseline versus six months post ultrasound RSD, p=0.04. Ultrasound RSD appears to be safe and an effective therapeutic approach in patients not responding to previous RSD with radiofrequency technology.

  19. Bipolar Disorder and Alcoholism: Are They Related?

    Science.gov (United States)

    ... Are they related? Is there a connection between bipolar disorder and alcoholism? Answers from Daniel K. Hall-Flavin, M.D. Bipolar disorder and alcoholism often occur together. Although the association ...

  20. Synergistic effect of mixed neutron and gamma irradiation in bipolar operational amplifier OP07

    Energy Technology Data Exchange (ETDEWEB)

    Yan, Liu, E-mail: liuyan@nint.ac.cn [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China); Wei, Chen; Shanchao, Yang; Xiaoming, Jin [State Key Laboratory of Intense Pulsed Irradiation Simulation and Effect, Northwest Institute of Nuclear Technology, P.O.Box 69-10, Xi’an 710024 (China); Chaohui, He [School of Nuclear Science and Technology, Xi’an Jiaotong University, Xi’an 710049 (China)

    2016-09-21

    This paper presents the synergistic effects in bipolar operational amplifier OP07. The radiation effects are studied by neutron beam, gamma ray, and mixed neutron/gamma ray environments. The characterateristics of the synergistic effects are studied through comparison of different experiment results. The results show that the bipolar operational amplifier OP07 exhibited significant synergistic effects in the mixed neutron and gamma irradiation. The bipolar transistor is identified as the most radiation sensitive unit of the operational amplifier. In this paper, a series of simulations are performed on bipolar transistors in different radiation environments. In the theoretical simulation, the geometric model and calculations based on the Medici toolkit are built to study the radiation effects in bipolar components. The effect of mixed neutron and gamma irradiation is simulated based on the understanding of the underlying mechanisms of radiation effects in bipolar transistors. The simulated results agree well with the experimental data. The results of the experiments and simulation indicate that the radiation effects in the bipolar devices subjected to mixed neutron and gamma environments is not a simple combination of total ionizing dose (TID) effects and displacement damage. The data suggests that the TID effect could enhance the displacement damage. The synergistic effect should not be neglected in complex radiation environments.

  1. Bipolar outflow in B335

    International Nuclear Information System (INIS)

    Hirano, N.; Kameya, O.; Nakayama, M.; Takakubo, K.

    1988-01-01

    The high-velocity (C-12)O (J = 1-0) emission in B335 with a high angular resolution of 16 arcsec has been mapped. The high-velocity emission shows distinct bipolar pattern centered at IRAS 19345+0727, toward which a strong high-velocity (C-12)O emission has been detected. The bipolar lobes delineate remarkable collimation toward the IRAS source, indicating that the flow is focused within 0.02 pc of the driving source. Each lobe is accompanied by significant wing emission with the opposite velocity shift, which clearly shows the association with IRAS 19345+0727. This feature is well explained as a bipolar flow the axis of which is nearly perpendicular to the line of sight. There is no evidence of another evolved bipolar flow which does not associate with any dense core as previously suggested. This suggests that B335 is a site of very recent star formation, containing a single bipolar flow with an age of about 30,000 yr. 15 references

  2. Exercising control over bipolar disorder.

    Science.gov (United States)

    Malhi, Gin S; Byrow, Yulisha

    2016-11-01

    Following extensive research exercise has emerged as an effective treatment for major depressive disorder, and it is now a recognised therapy alongside other interventions. In contrast, there is a paucity of research examining the therapeutic effects of exercise for those with bipolar disorder. Given that dysfunctional reward processing is central to bipolar disorder, research suggests that exercise can perhaps be framed as a reward-related event that may have the potential to precipitate a manic episode. The behavioural activation system (BAS) is a neurobehavioural system that is associated with responding to reward and provides an appropriate framework to theoretically examine and better understand the effects of exercise treatment on bipolar disorder. This article discusses recent research findings and provides an overview of the extant literature related to the neurobiological underpinnings of BAS and exercise as they relate to bipolar disorder. This is important clinically because depending on mood state in bipolar disorder, we postulate that exercise could be either beneficial or deleterious with positive or negative effects on the illness. Clearly, this complicates the evaluation of exercise as a potential treatment in terms of identifying its optimal characteristics in this population. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  3. Effect of component design in retrieved bipolar hip hemiarthroplasty systems.

    Science.gov (United States)

    Hess, Matthew D; Baker, Erin A; Salisbury, Meagan R; Kaplan, Lige M; Greene, Ryan T; Greene, Perry W

    2013-09-01

    Primary articulation of bipolar hemiarthroplasty systems is at the femoral head-liner interface. The purpose of this study was to compare observed damage modes on 36 retrieved bipolar systems with implant, demographic, intraoperative, and radiographic data to elucidate the effects of component design, specifically locking mechanism, on clinical performance. Retrieved bipolar hip hemiarthroplasty systems of 3 different design types were obtained, disassembled, and evaluated macro- and microscopically for varying modes of wear, including abrasion, burnishing, embedding, scratching, and pitting. Clinical record review and radiographic analysis were performed by a senior orthopedic surgery resident. Average bipolar hip hemiarthroplasty system term of service was 46 months (range, 0.27-187 months). All devices contained wear debris captured within the articulating space between the femoral head and liner. In 31% of patients without infection, lucency was observed on immediate prerevision radiographs. The system with a leaf locking mechanism showed significantly increased radiographically observed osteolysis (P=.03) compared with a system with a stopper ring locking mechanism. In addition, implant design and observed damage modes, including pitting and third-body particle embedding, were significantly associated with radiographically observed osteolysis. Copyright 2013, SLACK Incorporated.

  4. Late Onset Bipolar Disorder: Case Report

    OpenAIRE

    Filipa Araújo; Adriana Horta

    2016-01-01

    Background: Bipolar disorder affects approximately 1% of the population, with diagnosis often being made during late adolescence and early adulthood, and only rarely (0.1%) in the elderly. Late onset bipolar disorder in the elderly has a impact on the nature and course of bipolar disorder. Aims: The authors report a case of bipolar disorder emerging in late life  (76years old) with no cleary identified organic cause. Conclusion: This case highlights the importance of a broad different...

  5. Imunologia do transtorno bipolar Immunology of bipolar disorder

    Directory of Open Access Journals (Sweden)

    Izabela Guimarães Barbosa

    2009-01-01

    Full Text Available OBJETIVO: Pesquisas recentes têm implicado fatores imunes na patogênese de diversos transtornos neuropsiquiátricos. O objetivo do presente trabalho é revisar os trabalhos que investigaram a associação entre transtorno bipolar e alterações em parâmetros imunes. MÉTODOS: Artigos que incluíam as palavras-chave: "bipolar disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" e "tumor necrosis factor" foram selecionados em uma revisão sistemática da literatura. As bases de dados avaliadas foram MedLine e Scopus, entre os anos de 1980 e 2008. RESULTADOS: Foram identificados 28 trabalhos que estudaram alterações imunes em pacientes com transtorno bipolar. Seis artigos investigaram genes relacionados à resposta imune; cinco, autoanticorpos; quatro, populações leucocitárias; 13, citocinas e/ou moléculas relacionadas à resposta imune e seis, leucócitos de pacientes in vitro. CONCLUSÕES: Embora haja evidências na literatura correlacionando o transtorno bipolar a alterações imunes, os dados não são conclusivos. O transtorno bipolar parece estar associado a níveis mais elevados de autoanticorpos circulantes, assim como à tendência à ativação imune com produção de citocinas pró-inflamatórias e redução de parâmetros anti-inflamatórios.OBJECTIVE: Emerging research has implicated immune factors in the pathogenesis of a variety of neuropsychiatric disorders. The objective of the present paper is to review the studies that investigated the association between bipolar disorder and immune parameters. METHODS: Papers that included the keywords "bipolar to disorder", "mania", "immunology", "cytokines", "chemokines", "interleukins", "interferon" and "tumor necrosis factor" were selected in a systematic review of the literature. The evaluated databases were MedLine and Scopus in the period between 1980 and 2008. RESULTS: Twenty eight works were found. Six studies investigated immune response

  6. High-frequency noise modeling of Si(Ge) bipolar transistors

    NARCIS (Netherlands)

    Vitale, F.

    2014-01-01

    The design and the optimization of electronic systems often requires a detailed knowledge of the inherent noise generated within semiconductor active devices, constituting the core of such systems. Examples of applications in which noise is a key issue include receiver front-ends in radiofrequency

  7. Electronic devices and circuits

    CERN Document Server

    Pridham, Gordon John

    1972-01-01

    Electronic Devices and Circuits, Volume 3 provides a comprehensive account on electronic devices and circuits and includes introductory network theory and physics. The physics of semiconductor devices is described, along with field effect transistors, small-signal equivalent circuits of bipolar transistors, and integrated circuits. Linear and non-linear circuits as well as logic circuits are also considered. This volume is comprised of 12 chapters and begins with an analysis of the use of Laplace transforms for analysis of filter networks, followed by a discussion on the physical properties of

  8. Optically switched graphene/4H-SiC junction bipolar transistor

    Science.gov (United States)

    Chandrashekhar, MVS; Sudarshan, Tangali S.; Omar, Sabih U.; Brown, Gabriel; Shetu, Shamaita S.

    2018-05-08

    A bi-polar device is provided, along with methods of making the same. The bi-polar device can include a semiconductor substrate doped with a first dopant, a semiconductor layer on the first surface of the semiconductor substrate, and a Schottky barrier layer on the semiconductor layer. The method of forming a bi-polar device can include: forming a semiconductor layer on a first surface of a semiconductor substrate, where the semiconductor substrate comprises a first dopant and where the semiconductor layer comprises a second dopant that has an opposite polarity than the first dopant; and forming a Schottky barrier layer on a first portion of the semiconductor layer while leaving a second portion of the semiconductor layer exposed.

  9. Mathematical models of bipolar disorder

    Science.gov (United States)

    Daugherty, Darryl; Roque-Urrea, Tairi; Urrea-Roque, John; Troyer, Jessica; Wirkus, Stephen; Porter, Mason A.

    2009-07-01

    We use limit cycle oscillators to model bipolar II disorder, which is characterized by alternating hypomanic and depressive episodes and afflicts about 1% of the United States adult population. We consider two non-linear oscillator models of a single bipolar patient. In both frameworks, we begin with an untreated individual and examine the mathematical effects and resulting biological consequences of treatment. We also briefly consider the dynamics of interacting bipolar II individuals using weakly-coupled, weakly-damped harmonic oscillators. We discuss how the proposed models can be used as a framework for refined models that incorporate additional biological data. We conclude with a discussion of possible generalizations of our work, as there are several biologically-motivated extensions that can be readily incorporated into the series of models presented here.

  10. A new bipolar RRAM selector based on anti-parallel connected diodes for crossbar applications

    International Nuclear Information System (INIS)

    Li, Yingtao; Gong, Qingchun; Li, Rongrong; Jiang, Xinyu

    2014-01-01

    Crossbar arrays are the most promising application of a resistive random access memory (RRAM) device for achieving high density memory. However, cross-talk interference in the crossbar array limits the increase in the integration density. In this paper, the combination of two anti-parallel connected diodes and a bipolar RRAM cell is proposed to suppress the sneak current in a crossbar array with anti-parallel connected diodes as the selector for the bipolar RRAM. By using the anti-parallel connected diodes as a selector, the sneak current can be effectively suppressed and the high density crossbar array of more than 1 Mb can be realized as estimated by the 1/2V read voltage scheme. These results indicate that anti-parallel connected diodes can be used as a bipolar selector and have great potential for high density bipolar RRAM crossbar array applications. (papers)

  11. Recent advances in understanding total-dose effects in bipolar transistors

    International Nuclear Information System (INIS)

    Schrimpf, R.D.

    1996-01-01

    Gain degradation in irradiated bipolar transistors can be a significant problem, particularly in linear integrated circuits. In many bipolar technologies, the degradation is greater for irradiation at low dose rates than it is for typical laboratory dose rates. Ionizing radiation causes the base current in bipolar transistors to increase, due to the presence of net positive charge in the oxides covering sensitive device areas and increases in surface recombination velocity. Understanding the mechanisms responsible for radiation-induced gain degradation in bipolar transistors is important in developing appropriate hardness assurance methods. This paper reviews recent modeling and experimental work, with the emphasis on low-dose-rate effects. A promising hardness assurance method based on irradiation at elevated temperatures is described

  12. Charge Yield at Low Electric Fields: Considerations for Bipolar Integrated Circuits

    Science.gov (United States)

    Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

    2013-01-01

    A significant reduction in total dose damage is observed when bipolar integrated circuits are irradiated at low temperature. This can be partially explained by the Onsager theory of recombination, which predicts a strong temperature dependence for charge yield under low-field conditions. Reduced damage occurs for biased as well as unbiased devices because the weak fringing field in thick bipolar oxides only affects charge yield near the Si/SiO2 interface, a relatively small fraction of the total oxide thickness. Lowering the temperature of bipolar ICs - either continuously, or for time periods when they are exposed to high radiation levels - provides an additional degree of freedom to improve total dose performance of bipolar circuits, particularly in space applications.

  13. Is bipolar always bipolar? Understanding the controversy on bipolar disorder in children

    Science.gov (United States)

    Grimmer, Yvonne; Hohmann, Sarah

    2014-01-01

    Dramatically increasing prevalence rates of bipolar disorder in children and adolescents in the United States have provoked controversy regarding the boundaries of manic symptoms in child and adolescent psychiatry. The serious impact of this ongoing debate on the treatment of affected children is reflected in the concomitant increase in prescription rates for antipsychotic medication. A key question in the debate is whether this increase in bipolar disorder in children and adolescents is based on a better detection of early-onset bipolar disorder—which can present differently in children and adolescents—or whether it is caused by an incorrect assignment of symptoms which overlap with other widely known disorders. So far, most findings suggest that the suspected symptoms, in particular chronic, non-episodic irritability (a mood symptom presenting with easy annoyance, temper tantrums and anger) do not constitute a developmental presentation of childhood bipolar disorder. Additional research based on prospective, longitudinal studies is needed to further clarify the developmental trajectories of bipolar disorder and the diagnostic status of chronic, non-episodic irritability. PMID:25580265

  14. New resonant circuits for the ISOLTRAP radiofrequency quadrupole trap

    CERN Document Server

    SENECAL, Pierre

    2015-01-01

    This report describes my work during my Summer Student Program. My main project was building and testing a resonance-circuit box for a radio-frequency power supply used with the radio-frequency cooler and buncher.

  15. Radiofrequency ablation of pulmonary tumors

    Energy Technology Data Exchange (ETDEWEB)

    Crocetti, Laura, E-mail: l.crocetti@med.unipi.i [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy); Lencioni, Riccardo [Division of Diagnostic Imaging and Intervention, Department of Liver Transplants, Hepatology and Infectious Diseases, Pisa University School of Medicine (Italy)

    2010-07-15

    The development of image-guided percutaneous techniques for local tumor ablation has been one of the major advances in the treatment of solid tumors. Among these methods, radiofrequency (RF) ablation is currently established as the primary ablative modality at most institutions. RF ablation is accepted as the best therapeutic choice for patients with early-stage hepatocellular carcinoma when liver transplantation or surgical resection are not suitable options and is considered as a viable alternate to surgery for inoperable patients with limited hepatic metastatic disease, especially from colorectal cancer. Recently, RF ablation has been demonstrated to be a safe and valuable treatment option for patients with unresectable or medically inoperable lung malignancies. Resection should remain the standard therapy for non-small cell lung cancer (NSCLC) but RF ablation may be better than conventional external-beam radiation for the treatment of the high-risk individual with NSCLC. Initial favourable outcomes encourage combining radiotherapy and RF ablation, especially for treating larger tumors. In the setting of colorectal cancer lung metastases, survival rates provided by RF ablation in selected patients, are substantially higher than those obtained with any chemotherapy regimens and provide indirect evidence that RF ablation therapy improves survival in patients with limited lung metastatic disease.

  16. Dielectric-filled radiofrequency linacs

    Energy Technology Data Exchange (ETDEWEB)

    Faehl, R J; Keinigs, R K; Pogue, E W [Los Alamos National Lab., NM (United States)

    1997-12-31

    High current, high brightness electron beam accelerators promise to open up dramatic new applications. Linear induction accelerators are currently viewed as the appropriate technology for these applications. A concept by Humphries and Hwang may permit radiofrequency accelerators to fulfill the same functions with greater simplicity and enhanced flexibility. This concept involves the replacement of vacuum rf cavities with dielectric filled ones. Simple analysis indicates that the resonant frequencies are reduced by a factor of ({epsilon}{sub 0}/{epsilon}){sup 1/2} while the stored energy is increased by {epsilon}/{epsilon}{sub 0}. For a high dielectric constant like water, this factor can approach 80. A series of numerical calculations of simple pill-box cavities was performed. Eigenfunctions and resonant frequencies for a full system configuration, including dielectric material, vacuum beamline, and a ceramic window separating the two have been computed. These calculations are compared with the results of a small experimental cavity which have been constructed and operated. Low power tests show excellent agreement. (author). 4 figs., 8 refs.

  17. The radiofrequency magnetic dipole discharge

    Energy Technology Data Exchange (ETDEWEB)

    Martines, E., E-mail: emilio.martines@igi.cnr.it; Zuin, M.; Cavazzana, R.; Fassina, A.; Spolaore, M. [Consorzio RFX (CNR, ENEA, INFN, Università di Padova, Acciaierie Venete SpA), Corso Stati Uniti 4, 35127 Padova (Italy); Marcante, M. [Dipartimento di Fisica, Università di Trento, via Sommarive 14, 38123 Povo, TN (Italy); TIFPA, Trento Institute for Fundamental Physics and Applications INFN, 38123 Trento (Italy)

    2016-05-15

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3–4 eV and higher in the cathode proximity. Plasma densities of the order of 10{sup 16 }m{sup −3} have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  18. The radiofrequency magnetic dipole discharge

    Science.gov (United States)

    Martines, E.; Zuin, M.; Marcante, M.; Cavazzana, R.; Fassina, A.; Spolaore, M.

    2016-05-01

    This paper describes a novel and simple concept of plasma source, which is able to produce a radiofrequency magnetized discharge with minimal power requirements. The source is based on the magnetron concept and uses a permanent magnet as an active electrode. The dipolar field produced by the magnet confines the electrons, which cause further ionization, thus producing a toroidally shaped plasma in the equatorial region around the electrode. A plasma can be ignited with such scheme with power levels as low as 5 W. Paschen curves have been built for four different working gases, showing that in Helium or Neon, plasma breakdown is easily obtained also at atmospheric pressure. The plasma properties have been measured using a balanced Langmuir probe, showing that the electron temperature is around 3-4 eV and higher in the cathode proximity. Plasma densities of the order of 1016 m-3 have been obtained, with a good positive scaling with applied power. Overall, the electron pressure appears to be strongly correlated with the magnetic field magnitude in the measurement point.

  19. Bipolar dislocation of the clavicle

    Directory of Open Access Journals (Sweden)

    Wei Jiang

    2012-01-01

    Full Text Available Bipolar dislocation of the clavicle at acromioclavicular and sternoclavicular joint is an uncommon traumatic injury. The conservative treatments adopted in the past is associated with redislocation dysfunction and deformity. A 41 years old lady with bipolar dislocation of right shoulder is treated surgically by open reduction and internal fixation by oblique T-plate at sternoclavicular joint and Kirschner wire stabilization at acromioclavicular joint. The patient showed satisfactory recovery with full range of motion of the right shoulder and normal muscular strength. The case reported in view of rarity and at 2 years followup.

  20. Transcultural aspects of bipolar disorder

    OpenAIRE

    Sanches, Marsal; Jorge, Miguel Roberto

    2004-01-01

    Considerando-se que existem diferenças importantes na maneira como as emoções são vivenciadas e expressas em diferentes culturas, a apresentação e o manejo do transtorno afetivo bipolar sofrem influência de fatores culturais. O presente artigo realiza uma breve revisão da evidência referente aos aspectos transculturais do transtorno bipolar.Cultural variations in the expression of emotions have been described. Consequently, there are cross-cultural influences on the diagnosis and management o...

  1. Ablation of liver metastases by radiofrequency

    International Nuclear Information System (INIS)

    Baere, T. de

    2012-01-01

    Radiofrequency is a thermal ablative technique that is most often used percuteanously under image guidance. Thermal damage is obtained through frictional heating of a high frequency current. The maximal volume of destruction obtained in one radiofrequency delivery is around 4 cm and consequently, best indication for treatment are tumours below 3 cm. When compared, radiofrequency and surgical removal for tumours below 25 mm in diameter demonstrated a rate of incomplete resection/ablation of 6% and 7.3% respectively. Median survival after the first radiofrequency of a liver metastasis of CRC is reported to be 24 to 52 months with a 5 years overall survival of 18 to 44%. The median overall survival increases from 22 to 48 months depending on the use of radiofrequency ablation as rescue treatment after failure of others, or as a first line treatment. For patients with a single tumour, less than 4 cm, the survival rates at 1, 3, and 5 years are respectively 97%, 84% and 40%, with a median survival of 50 months. Follow-up imaging requires to use contrast-enhanced CT or MRI, looking for local recurrences evidenced by local foci of enhancement at the periphery of the ablation zone. (author)

  2. 47 CFR 1.1310 - Radiofrequency radiation exposure limits.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Radiofrequency radiation exposure limits. 1... Procedures Implementing the National Environmental Policy Act of 1969 § 1.1310 Radiofrequency radiation... exposure to radiofrequency (RF) radiation as specified in § 1.1307(b), except in the case of portable...

  3. A novel technique for CAD-optimization of analog circuits with bipolar transistors

    Directory of Open Access Journals (Sweden)

    B. Dimov

    2009-05-01

    Full Text Available In this paper, a novel approach for robust automatic optimization of analog circuits with bipolar transistors is presented. It includes additional formal parameters into the device model cards, which sweep the model parameters smoothly between the different device types. In this way, not only the sizing, but also the choice of the device type is committed to the optimization tool, thus improving the efficiency of the design process significantly.

  4. High-gain bipolar detector on float-zone silicon

    Science.gov (United States)

    Han, D. J.; Batignani, G.; Del Guerra, A.; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-10-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ˜7.77×10 4/s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device.

  5. High-gain bipolar detector on float-zone silicon

    International Nuclear Information System (INIS)

    Han, D.J.; Batignani, G.; Guerra, A.D.A. Del; Dalla Betta, G.-F.; Boscardin, M.; Bosisio, L.; Giorgi, M.; Forti, F.

    2003-01-01

    Since the float-zone (FZ) silicon has lower contaminations and longer minority-carrier lifetime than those in Czochralski silicon and other semiconductor materials, it has potential advantages to fabricate bipolar detectors on the high-purity FZ silicon substrate to achieve a high gain at ultra-low-signal levels. The authors present preliminary experimental results on a bipolar detector fabricated on an unusual high-purity FZ silicon substrate. A backside gettering layer of phosphorus-doped polysilicon was employed to preserve the long carrier lifetime of the high-purity FZ silicon. The device has been investigated in the detection of a continuous flux of X-ray and infrared light. The bipolar detector with a circular emitter of 2 mm diameter has demonstrated high gains up to 3820 for 22 keV X-ray from a 1 mCi Cd radioactive source (the X-ray photon flux, received by the detector is estimated to be ∼7.77x10 4 /s). High gain up to 4400 for 0.17 nW light with a wavelength of 0.83 μm has been observed for the same device

  6. Radiofrequency-thermoablation in malignant liver disease

    International Nuclear Information System (INIS)

    Pichler, L.; Anzboeck, W.; Paertan, G.; Hruby, W.

    2002-01-01

    The clinical application of radiofrequency tumor ablation in primary liver tumors and metastatic liver disease is rapidly growing because this technique has proven to be simple, safe, and effective in first clinical studies. Most of the patients with malignant liver disease are not candidates for surgical resection due localisation or comorbidity, so radiofrequency therapy offers a good alternative for inoperable patients. With this method, high frequency alternating current is delivered to tissue via a needle electrode, the produced heat leads to coagulation necrosis. The largest focus of necrosis that can be induced with the currently available systems is approximately 4-5 cm with a single application. The radiofrequency needle is usually placed with US or CT guidance. For follow up examinations CT and MRI can be used, they proved to be equally accurate in the assessment of treatment response. (orig.) [de

  7. Radiofrequency assisted pancreaticoduodenectomy for palliative surgical resection of locally advanced pancreatic adenocarcinoma.

    Science.gov (United States)

    Kumar, Jayant; Reccia, Isabella; Sodergren, Mikael H; Kusano, Tomokazu; Zanellato, Artur; Pai, Madhava; Spalding, Duncan; Zacharoulis, Dimitris; Habib, Nagy

    2018-03-20

    Despite careful patient selection and preoperative investigations curative resection rate (R0) in pancreaticoduodenectomy ranges from 15% to 87%. Here we describe a new palliative approach for pancreaticoduodenectomy using a radiofrequency energy device to ablate tumor in situ in patients undergoing R1/R2 resections for locally advanced pancreatic ductal adenocarcinoma where vascular reconstruction was not feasible. There was neither postoperative mortality nor significant morbidity. Each time the ablation lasted less than 15 minutes. Following radiofrequency ablation it was observed that the tumor remnant attached to the vessel had shrunk significantly. In four patients this allowed easier separation and dissection of the ablated tumor from the adherent vessel leading to R1 resection. In the other two patients, the ablated tumor did not separate from vessel due to true tumor invasion and patients had an R2 resection. The ablated remnant part of the tumor was left in situ. Whenever pancreaticoduodenectomy with R0 resection cannot be achieved, this new palliative procedure could be considered in order to facilitate resection and enable maximum destruction in remnant tumors. Six patients with suspected tumor infiltration and where vascular reconstruction was not warranted underwent radiofrequency-assisted pancreaticoduodenectomy for locally advanced pancreatic ductal adenocarcinoma. Radiofrequency was applied across the tumor vertically 5-10 mm from the edge of the mesenteric and portal veins. Following ablation, the duodenum and the head of pancreas were removed after knife excision along the ablated line. The remaining ablated tissue was left in situ attached to the vessel.

  8. Vacuum pumping system for the JT-60 radio-frequency heating system

    International Nuclear Information System (INIS)

    Yokokura, Kenji; Ikeda, Yoshitaka; Imai, Tuyoshi; Suganuma, Kazuaki; Nagashima, Takashi

    1988-01-01

    The basic design requirements set up for the JT-60 radio-frequency heating system included: (1) rapid pumping of gas released upon application of a radio-frequency power to maintain the pressure in the launchers at 10 -2 - 10 -3 Pa or less, (2) incorporation of a gas analysis system that can operate under a strong field and high pressure (>10 -2 Pa) to permit remote controlled data collection and processing, and (3) low cost, multiple functions and high reliability. The vacuum pumping system, consisting of three units for low hybrid radio-frequency (LHRF) and one unit for ion cyclotron radio-frequency (ICRF), is connected to each launcher provided at the four ports of JT-60. The LHRF unit is composed of a main pump, an alumina joint for electrical insulation from the launcher, a metallic gate valve for isolation from the JT-60 vacuum region, and various vacuum gauges. Only a turbo-molecular pump is used for the ICRF system because a large-scale differential pumping is not required. A gas measuring system is incorporated which consists of a mass filter, personal computer, turbo-molecular pump, and variable flow valve equipped with an APG control. This system is designed to identify and make use of gas impurities released during the launcher aging process. The control system employed consists of a personal computer, interlock control board, data logger and other devices such as vacuum gages. (Nogami, K.)

  9. Social support and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Paula Mendonça Studart

    2015-08-01

    Full Text Available Background Bipolar disorder is a chronic condition that affects the functioning of its carriers in many different ways, even when treated properly. Therefore, it’s also important to identify the psychosocial aspects that could contribute to an improvement of this population’s quality of life.Objective Carry out a literature review on the role of social support in cases of bipolar disorder.Method A research on the following online databases PubMed, Lilacs and SciELO was conducted by using the keywords “social support” or “social networks” and “mood disorders” or “bipolar disorder” or “affective disorder,” with no defined timeline.Results Only 13 studies concerning the topic of social support and BD were found in the search for related articles. Generally speaking, the results show low rates of social support for BD patients.Discussion Despite the growing interest in the overall functioning of patients with bipolar disorder, studies on social support are still rare. Besides, the existing studies on the subject use different methodologies, making it difficult to establish data comparisons.

  10. Electronic monitoring in bipolar disorder

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Maria

    2018-01-01

    generated data (e.g. the number of text messages sent/day; the number of incoming and outgoing calls/day; the number of changes in cell tower IDs/day; and voice features) seem to reflect clinically assessed depressive and manic symptoms in bipolar disorder; 3) smartphone-based electronic self-monitoring had...

  11. Integrated Neurobiology of Bipolar Disorder

    Science.gov (United States)

    Maletic, Vladimir; Raison, Charles

    2014-01-01

    From a neurobiological perspective there is no such thing as bipolar disorder. Rather, it is almost certainly the case that many somewhat similar, but subtly different, pathological conditions produce a disease state that we currently diagnose as bipolarity. This heterogeneity – reflected in the lack of synergy between our current diagnostic schema and our rapidly advancing scientific understanding of the condition – limits attempts to articulate an integrated perspective on bipolar disorder. However, despite these challenges, scientific findings in recent years are beginning to offer a provisional “unified field theory” of the disease. This theory sees bipolar disorder as a suite of related neurodevelopmental conditions with interconnected functional abnormalities that often appear early in life and worsen over time. In addition to accelerated loss of volume in brain areas known to be essential for mood regulation and cognitive function, consistent findings have emerged at a cellular level, providing evidence that bipolar disorder is reliably associated with dysregulation of glial–neuronal interactions. Among these glial elements are microglia – the brain’s primary immune elements, which appear to be overactive in the context of bipolarity. Multiple studies now indicate that inflammation is also increased in the periphery of the body in both the depressive and manic phases of the illness, with at least some return to normality in the euthymic state. These findings are consistent with changes in the hypothalamic–pituitary–adrenal axis, which are known to drive inflammatory activation. In summary, the very fact that no single gene, pathway, or brain abnormality is likely to ever account for the condition is itself an extremely important first step in better articulating an integrated perspective on both its ontological status and pathogenesis. Whether this perspective will translate into the discovery of innumerable more homogeneous forms of

  12. Radio-frequency integrated-circuit engineering

    CERN Document Server

    Nguyen, Cam

    2015-01-01

    Radio-Frequency Integrated-Circuit Engineering addresses the theory, analysis and design of passive and active RFIC's using Si-based CMOS and Bi-CMOS technologies, and other non-silicon based technologies. The materials covered are self-contained and presented in such detail that allows readers with only undergraduate electrical engineering knowledge in EM, RF, and circuits to understand and design RFICs. Organized into sixteen chapters, blending analog and microwave engineering, Radio-Frequency Integrated-Circuit Engineering emphasizes the microwave engineering approach for RFICs. Provide

  13. Transurethral radiofrequency collagen denaturation for the treatment of women with urinary incontinence.

    Science.gov (United States)

    Kang, Diana; Han, Julia; Neuberger, Molly M; Moy, M Louis; Wallace, Sheila A; Alonso-Coello, Pablo; Dahm, Philipp

    2015-03-18

    Transurethral radiofrequency collagen denaturation is a relatively novel, minimally invasive device-based intervention used to treat individuals with urinary incontinence (UI). No systematic review of the evidence supporting its use has been published to date. To evaluate the efficacy of transurethral radiofrequency collagen denaturation, compared with other interventions, in the treatment of women with UI.Review authors sought to compare the following.• Transurethral radiofrequency collagen denaturation versus no treatment/sham treatment.• Transurethral radiofrequency collagen denaturation versus conservative physical treatment.• Transurethral radiofrequency collagen denaturation versus mechanical devices (pessaries for UI).• Transurethral radiofrequency collagen denaturation versus drug treatment.• Transurethral radiofrequency collagen denaturation versus injectable treatment for UI.• Transurethral radiofrequency collagen denaturation versus other surgery for UI. We conducted a systematic search of the Cochrane Incontinence Group Specialised Register (searched 19 December 2014), EMBASE and EMBASE Classic (January 1947 to 2014 Week 50), Google Scholar and three trials registries in December 2014, along with reference checking. We sought to identify unpublished studies by handsearching abstracts of major gynaecology and urology meetings, and by contacting experts in the field and the device manufacturer. Randomised and quasi-randomised trials of transurethral radiofrequency collagen denaturation versus no treatment/sham treatment, conservative physical treatment, mechanical devices, drug treatment, injectable treatment for UI or other surgery for UI in women were eligible. We screened search results and selected eligible studies for inclusion. We assessed risk of bias and analysed dichotomous variables as risk ratios (RRs) with 95% confidence intervals (CIs) and continuous variables as mean differences (MDs) with 95% CIs. We rated the quality of

  14. Recent progress in power electronic devices

    Energy Technology Data Exchange (ETDEWEB)

    Ikeda, Yasuhiko; Yatsuo, Tsutomu

    1987-02-01

    Recent progress and future trends of power semiconductor devices (especially with respect to motor speed control) were described. Conventional discrete devices such as thyristors, bipolar transistors, unipolar transistors and Bi-MOS devices were referenced to. Reference was also made to High Voltage ICs. There has been steady progress with each of these power devices in current carrying capability, voltage blocking capability and switching speed. The Bipolar-MOS integreated device and the High Voltage IC are particularly interesting because their abilities and performances are much enhanced by skillful combination with conventional discrete devices. However, no one device meets all the needs, and it will always be necessary to select the right device for a specific task. (11 figs, 35 refs)

  15. Pulmonary hemorrhage complicating radiofrequency ablation, from mild hemoptysis to life-threatening pattern

    Energy Technology Data Exchange (ETDEWEB)

    Nour-Eldin, Nour-Eldin A.; Naguib, Nagy N.N.; Mack, Martin; Abskharon, John E.; Vogl, Thomas J. [Johann Wolfgang Goethe-University Hospital, Institute for Diagnostic and Interventional Radiology, Frankfurt am Main (Germany)

    2011-01-15

    To assess risk factors and the extent of pulmonary hemorrhage complicating radiofrequency ablation (RFA) of pulmonary neoplasms. This retrospective study involved 248 ablation sessions for lung tumors (20 primary lesions and 228 metastatic lesions) in 164 patients (mean age 59.7 years, SD: 10.2). Both unipolar and bipolar radiofrequency systems were used under CT fluoroscopic guidance. Extent and underlying factors associated with development of pulmonary hemorrhage were analyzed. Incidence of intra-parenchymal pulmonary hemorrhage, pleural effusion, and hemoptysis were 17.7% (44/248 sessions), 4% (8/248 sessions), and 16.1% (40/248 sessions), respectively. Death because of massive bleeding occurred in one session (0.4%). Significant risk factors associated with intra-parenchymal hemorrhage included: lesions of <1.5 cm diameter (P = 0.007); basal and middle lung zone lesions (P = 0.026); increased needle track distance traversing the lung parenchyma >2.5 cm (P = 0.0017); traversing pulmonary vessels in the track of ablation (P < 0.001); and the use of multi-tined electrodes (P = 0.004). Concomitant incidence of pulmonary hemorrhage and pneumothorax was 29.2% (14/48 sessions). While typically safe, RFA of pulmonary neoplasms can result in pulmonary hemorrhage ranging from mild to life-threatening. Management of this complication is mainly preventive through adequate patient selection for ablation therapy and exclusion of technically avoidable risk factors. (orig.)

  16. Solid-state devices and applications

    CERN Document Server

    Lewis, Rhys

    1971-01-01

    Solid-State Devices and Applications is an introduction to the solid-state theory and its devices and applications. The book also presents a summary of all major solid-state devices available, their theory, manufacture, and main applications. The text is divided into three sections. The first part deals with the semiconductor theory and discusses the fundamentals of semiconductors; the kinds of diodes and techniques in their manufacture; the types and modes of operation of bipolar transistors; and the basic principles of unipolar transistors and their difference with bipolar transistors. The s

  17. The radiofrequency frontier: a review of radiofrequency and combined radiofrequency pulsed-light technology in aesthetic medicine.

    Science.gov (United States)

    Sadick, Neil; Sorhaindo, Lian

    2005-05-01

    Radiofrequency (RF) and combined RF light source technologies have established themselves as safe and effective treatment modalities for several dermatologic procedures, including skin tightening, hair and leg vein removal, acne scarring, skin rejuvenation, and wrinkle reduction. This article reviews the technology, clinical applications, and recent advances of RF and combined RF light/laser source technologies in aesthetic medicine.

  18. Radiofrequency energy exposure from the Trilliant smart meter.

    Science.gov (United States)

    Foster, Kenneth R; Tell, Richard A

    2013-08-01

    This paper reviews radiofrequency (RF) field levels produced by electric utility meters equipped with RF transceivers (so-called Smart Meters), focusing on meters from one manufacturer (Trilliant, Redwood City, CA, USA, and Granby, QC, Canada). The RF transmission levels are summarized based on publicly available data submitted to the U.S. Federal Communications Commission supplemented by limited independent measurements. As with other Smart Meters, this meter incorporates a low powered radiofrequency transceiver used for a neighborhood mesh network, in the present case using ZigBee-compliant physical and medium access layers, operating in the 2.45 GHz unlicensed band but with a proprietary network architecture. Simple calculations based on a free space propagation model indicate that peak RF field intensities are in the range of 10 mW m or less at a distance of more than 1-2 m from the meters. However, the duty cycle of transmission from the meters is very low (meter that were consistent with data reported by the vendor to the U.S. Federal Communications Commission. Limited measurements conducted in two houses with the meters were unable to clearly distinguish emissions from the meters from the considerable electromagnetic clutter in the same frequency range from other sources, including Wi-Fi routers and, when it was activated, a microwave oven. These preliminary measurements disclosed the difficulties that would be encountered in characterizing the RF exposures from these meters in homes in the face of background signals from other household devices in the same frequency range. An appendix provides an introduction to Smart Meter technology. The RF transmitters in wireless-equipped Smart Meters operate at similar power levels and in similar frequency ranges as many other digital communications devices in common use, and their exposure levels are very far below U.S. and international exposure limits.

  19. Unidirectional threshold switching in Ag/Si-based electrochemical metallization cells for high-density bipolar RRAM applications

    Science.gov (United States)

    Wang, Chao; Song, Bing; Li, Qingjiang; Zeng, Zhongming

    2018-03-01

    We herein present a novel unidirectional threshold selector for cross-point bipolar RRAM array. The proposed Ag/amorphous Si based threshold selector showed excellent threshold characteristics in positive field, such as high selectivity ( 105), steep slope (type RRAM. By integrating a bipolar RRAM device with the selector, experiments showed that the undesired sneak was significantly suppressed, indicating its potentiality for high-density integrated nonvolatile memory applications.

  20. Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects

    International Nuclear Information System (INIS)

    Balmori, Alfonso

    2016-01-01

    Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found. - Highlights: • Radiotracking may induce negative effects that can bias the results. • Effects have been documented on survival, reproduction and behaviour.

  1. Radiotelemetry and wildlife: Highlighting a gap in the knowledge on radiofrequency radiation effects

    Energy Technology Data Exchange (ETDEWEB)

    Balmori, Alfonso, E-mail: balmaral@jcyl.es

    2016-02-01

    Radio transmitters and associated devices may induce negative effects that can bias the results of ongoing research. The main documented effects of radio transmitters on animals include reduced survival, decreased productivity, changes in behaviour and movement patterns and a biased sex ratio. The only factors that have claimed responsibility for these possible damages are the weight of the radio transmitter and associated devices, and the attachment type. The electromagnetic radiation produced by radio transmitters has not been considered so far in research. There have been no studies evaluating the effects of non-ionising electromagnetic radiation (radiofrequency signals) necessary for tracking, although the problems found were significantly associated with the length of time that animals had been carrying their radio transmitters. Similar problems as those in radiotracked animals have been found in numerous studies with animals exposed to radiofrequency radiation for a sufficient amount of time. Laboratory scientists investigating the orientation of animals know they have to shield the place where experiments are performed to prevent interference from man-made radiation, as anthropogenic signals may distort the results. It is paradoxical that, at the same time, field scientists investigating the movements and other aspects of animal biology are providing animals with radio transmitters that emit the same type of radiation, since this may affect the results concerning their orientation and movement. This paper identifies gaps in the knowledge that should be investigated in-depth. The possibility that the radiofrequency radiation from radiotracking devices is responsible for the findings should be considered. Considering this factor may allow researchers to best understand the long-term effects found. - Highlights: • Radiotracking may induce negative effects that can bias the results. • Effects have been documented on survival, reproduction and behaviour.

  2. Face expressive lifting (FEL): an original surgical concept combined with bipolar radiofrequency

    OpenAIRE

    Divaris, Marc; Blugerman, Guillermo; Paul, Malcolm D.

    2013-01-01

    Background Aging can lead to changes in facial expressions, transforming the positive youth expression of happiness to negative expressions as sadness, tiredness, and disgust. Local skin distension is another consequence of aging, which can be difficult to treat with rejuvenation procedures. The “face expressive lifting” (FEL) is an original concept in facial rejuvenation surgery. On the one hand, FEL integrates established convergent surgical techniques aiming to correct the age-related nega...

  3. Modes of oscillation in radiofrequency Paul traps

    DEFF Research Database (Denmark)

    Landa, H.; Reznik, B.; Drewsen, M.

    2012-01-01

    We examine the time-dependent dynamics of ion crystals in radiofrequency traps. The problem of stable trapping of general threedimensional crystals is considered and the validity of the pseudopotential approximation is discussed. We analytically derive the micromotion amplitude of the ions...

  4. Pulsed Radiofrequency Ablation for Treating Sural Neuralgia.

    Science.gov (United States)

    Abd-Elsayed, Alaa; Jackson, Markus; Plovanich, Elizabeth

    2018-01-01

    Sural neuralgia is persistent pain in the distribution of the sural nerve that provides sensation to the lateral posterior corner of the leg, lateral foot, and fifth toe. Sural neuralgia is a rare condition but can be challenging to treat and can cause significant limitation. We present 2 cases of sural neuralgia resistant to conservative management that were effectively treated by pulsed radiofrequency ablation. A 65-year-old female developed sural neuralgia after a foot surgery and failed conservative management. She had successful sural nerve blocks, and pulsed radiofrequency ablation led to an 80% improvement in her pain. A 33-year-old female presented with sural neuralgia secondary to two falls. The patient had tried several conservative modalities with no success. We performed diagnostic blocks and pulsed radiofrequency ablation, and the patient reported 80% improvement in her pain. Pulsed radiofrequency ablation may be a safe and effective treatment for patients with sural neuralgia that does not respond to conservative therapy. However, studies are needed to elucidate its effectiveness and safety profile.

  5. Radiofrequency and microwave interactions between biomolecular systems

    Czech Academy of Sciences Publication Activity Database

    Kučera, Ondřej; Cifra, Michal

    2016-01-01

    Roč. 42, č. 1 (2016), s. 1-8 ISSN 0092-0606 R&D Projects: GA ČR(CZ) GA15-17102S Institutional support: RVO:67985882 Keywords : Cell signaling * Radiofrequency * Bioelectrodynamics Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.241, year: 2016

  6. Management of trigeminal neuralgia by radiofrequency ...

    African Journals Online (AJOL)

    The outcome depends on the type of TN with best results with classical idiopathic type. Also better results occurred with isolated V3 affection. The radiofrequency thermocoagulation of trigeminal nerve is a low risk, highly effective and minimally invasive procedure that should be started with in all cases of TN.

  7. Potential health risks due to telecommunications radiofrequency ...

    African Journals Online (AJOL)

    Background: The global system mobile telecommunications system (GSM) which was recently introduced in Nigeria is now being used by over 40 million people in Nigeria. The use of GSM is accompanied with exposure of the users to radiofrequency radiation (RFR), which if significant, may produce health hazards. This is ...

  8. Radiofrequency catheter oblation in atrial flutter

    International Nuclear Information System (INIS)

    Yan Ji; Wang Heping; Xu Jian; Liu Fuyuan; Fan Xizhen; An Chunsheng; Han Xiaoping; Ding Xiaomei; Wang Jiasheng; Gu Tongyuan

    2002-01-01

    Objective: To evaluate the radiofrequency catheter ablation for type I atrial flutter through application of Holo catheter labelling with anatomic imaging localization to ablate the isthmus of IVCTA during complete double-way block. Methods: Eleven cases with type I atrial flutter undergone Holo catheter labelling technique and consecution with conduction time change of coronary venous sinus orifice with-right atrial lower lateral wall pace excitation, were performed with radiofrequency catheter ablation for the isthmus outcoming with complete double-way conduction block. Results: All together 11 cases with 4 of atrial flutter and 7 of sinus rhythm were undergone radiofrequency catheter ablation resulting with double-way conduction block of the isthmus accompanied by prolongation of right atrial conduction time 56.0 ± 2.3 ms and 53.0 ± 4.6 ms respectively. The right atrial excitation appeared to be in clockwise and counter-clockwise of single direction. No recurrence occurred during 3-34 months follow up with only one showing atrial fibrillation. Conclusions: The application of Holo catheter labelling technique with anatomic imaging localization to achieve the double-way conduction block by radiofrequency catheter ablation of TVC-TA isthmus, is a reliable method for treating atrial flutter

  9. Bipolar polygenic loading and bipolar spectrum features in major depressive disorder

    NARCIS (Netherlands)

    Wiste, Anna; Robinson, Elise B.; Milaneschi, Yuri; Meier, Sandra; Ripke, Stephan; Clements, Caitlin C.; Fitzmaurice, Garrett M.; Rietschel, Marcella; Penninx, Brenda W.; Smoller, Jordan W.; Perlis, Roy H.

    Objectives Family and genetic studies indicate overlapping liability for major depressive disorder and bipolar disorder. The purpose of the present study was to determine whether this shared genetic liability influences clinical presentation. Methods A polygenic risk score for bipolar disorder,

  10. Effect of AlN layer on the bipolar resistive switching behavior in TiN thin film based ReRAM device for non-volatile memory application

    Science.gov (United States)

    Prakash, Ravi; Kaur, Davinder

    2018-05-01

    The effect of an additional AlN layer in the Cu/TiN/AlN/Pt stack configuration deposited using sputtering has been investigated. The Cu/TiN/AlN/Pt device shows a tristate resistive switching. Multilevel switching is facilitated by ionic and metallic filament formation, and the nature of the filaments formed is confirmed by performing a resistance vs. temperature measurement. Ohmic behaviour and trap controlled space charge limited current (SCLC) conduction mechanisms are confirmed as dominant conduction mechanism at low resistance state (LRS) and high resistance state (HRS). High resistance ratio (102) corresponding to HRS and LRS, good write/erase endurance (105) and non-volatile long retention (105s) are also observed. Higher thermal conductivity of the AlN layer is the main reasons for the enhancement of resistive switching performance in Cu/TiN/AlN/Pt cell. The above result suggests the feasibility of Cu/TiN/AlN/Pt devices for multilevel nonvolatile ReRAM application.

  11. Nano-Scale Devices for Frequency-Based Magnetic Biosensing

    Science.gov (United States)

    2017-01-31

    show the basic measurement setup (the field is applied perpendicular to the disk plane). A radiofrequency signal is injected across the disk (disks...shown in Fig. 7(a). A spectrum analyser (S.A.) (or a high frequency oscilloscope) is used to measure the radiofrequency STO output signal with Fig...crystals and, via electrical measurements , in magnetic-vortex-containing, isolated micro- and nano-devices. Via micromagnetic simulations, we have largely

  12. Interactions between radiofrequency signals and living organisms

    International Nuclear Information System (INIS)

    Boudin, F.; Hours, M.; Lacronique, J.F.; Conil, E.; Hadjem, A.; El Habachi, A.; Wiart, K.; Mann, S.; Kundi, M.; Marc-Vergnes, J.P.; Roosli, M.; Mohler, E.; Frei, P.; Davis, Ch.C.; Balzano, Q.; Ait-Aissa, S.; Billaudel, B.; Poulletier De Gannes, F.; Hurtier, A.; Haro, E.; Taxile, M.; Veyret, B.; Lagroye, I.; Ait-Aissa, S.; Poulletier De Gannes, F.; Athane, A.; Veyret, B.; Lagroye, I.; Yardin, C.; Perrin, A.; Freire, M.; Bachelet, Ch.; Collin, A.; Pla, S.; Debouzy, J.C.; Leveque, Ph.; Van Nierop, L.E.; Huss, A.; Roosli, M.; Egger, M.; Calvez, M.; Salomon, D.

    2010-01-01

    This dossier is composed of 13 articles dealing with the interactions between radio-frequencies and living organisms. It is an overview of various scientific approaches to the field and is of interest for all citizens as the use of mobile phones is widely spread. In the first article it is shown how a model has been built to assess the distribution of the whole body exposure of the population. The second article reviews the state of the art in personal exposure measurements at radio-frequencies. The third article shows that the knowledge of the mechanism of action by which exposure increases the risk of health hazards is necessary. The fourth article shows that individual neuro-psychic factors take a prominent but maybe not unique, part in electromagnetic hypersensitivity. The fifth article shows that no evidence was found to link health disturbances of electromagnetic hypersensitive individuals with radiofrequency exposure. The sixth article shows that the wireless phone is not an athermal hazard to the brain. The seventh article shows that the in utero and post-natal exposure to Wi-Fi does not damage the brains of young rats. The eighth article concludes that recent studies provide no convincing proof of deleterious effects of radiofrequency exposure on the integrity of the blood-brain barrier for specific absorption rates up to 6 W/kg. The ninth article shows that no co-genotoxic effect of radiofrequency was found at levels of exposure that did not induce heating. The tenth article confirms that industry-sponsored studies were least likely to report results suggesting effects. The last article shows that general practitioners are increasingly questioned by their patients about the issue of electromagnetic waves. (A.C.)

  13. Bicentric bipolar hip prosthesis: A radiological study of movement at the interprosthetic joint

    Directory of Open Access Journals (Sweden)

    Anil Kumar Rai

    2011-01-01

    Full Text Available Background: The bipolar hip prostheses after some time functions as a unipolar device. There is a need to change the design of bipolar hip prostheses to make it function as a bipolar device over a prolonged period of time. A bicentric bipolar hip prosthesis was used as an implant for various conditions of the hip. We evaluated the movement of this newly developed prosthesis at the interprosthetic joint radiologically at periodic intervals. Materials and Methods: Fifty two cases were operarted with the Bicentric bipolar prosthesis for indications like fracture neck of femur and various other diseases of the hip and were followed up with serial radiographs at periodic intervals to evaluate, what fraction of the total abduction at the hip was occurring at the interprosthetic joint. Results: In cases of intracapsular fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 33.74% (mean value of all the patients, which fell to 25.66% at 1.5 years. In indications for bipolar hemireplacement other than fracture neck of femur, the percentage of total abduction occurring at the interprosthetic joint at 3 months follow-up was 71.71% (mean value and at 1.5 years it was 67.52%. Conclusion: This study shows the relative preservation of inner bearing movement in the bipolar hip prosthesis with time probably due its refined design. Further refinements are needed to make the prosthesis work better in patients of intracapsular fracture neck femur.

  14. Unsplit bipolar pulse forming line

    Science.gov (United States)

    Rhodes, Mark A [Pleasanton, CA

    2011-05-24

    A bipolar pulse forming transmission line module and system for linear induction accelerators having first, second, third, and fourth planar conductors which form a sequentially arranged interleaved stack having opposing first and second ends, with dielectric layers between the conductors. The first and second planar conductors are connected to each other at the first end, and the first and fourth planar conductors are connected to each other at the second end via a shorting plate. The third planar conductor is electrically connectable to a high voltage source, and an internal switch functions to short at the first end a high voltage from the third planar conductor to the fourth planar conductor to produce a bipolar pulse at the acceleration axis with a zero net time integral. Improved access to the switch is enabled by an aperture through the shorting plate and the proximity of the aperture to the switch.

  15. Course of Subthreshold Bipolar Disorder in Youth: Diagnostic Progression from Bipolar Disorder Not Otherwise Specified

    Science.gov (United States)

    Axelson, David A.; Birmaher, Boris; Strober, Michael A.; Goldstein, Benjamin I.; Ha, Wonho; Gill, Mary Kay; Goldstein, Tina R.; Yen, Shirley; Hower, Heather; Hunt, Jeffrey I.; Liao, Fangzi; Iyengar, Satish; Dickstein, Daniel; Kim, Eunice; Ryan, Neal D.; Frankel, Erica; Keller, Martin B.

    2011-01-01

    Objective: To determine the rate of diagnostic conversion from an operationalized diagnosis of bipolar disorder not otherwise specified (BP-NOS) to bipolar I disorder (BP-I) or bipolar II disorder (BP-II) in youth over prospective follow-up and to identify factors associated with conversion. Method: Subjects were 140 children and adolescents…

  16. Bipolar (spectrum) disorder and mood stabilization: standing at the crossroads?

    OpenAIRE

    De Fruyt, Jurgen; Demyttenaere, Koen

    2007-01-01

    Diagnosis and treatment of bipolar disorder has long been a neglected discipline. Recent years have shown an upsurge in bipolar research. When compared to major depressive disorder, bipolar research still remains limited and more expert based than evidence based. In bipolar diagnosis the focus is shifting from classic mania to bipolar depression and hypomania. There is a search for bipolar signatures in symptoms and course of major depressive episodes. The criteria for hypomania are softened,...

  17. [Bipolar disorders in DSM-5].

    Science.gov (United States)

    Severus, E; Bauer, M

    2014-05-01

    In spring 2013 the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) edited by the American Psychiatric Association was published. The DSM-5 has also brought some important changes regarding bipolar disorders. The goal of this manuscript is to review the novelties in DSM-5 and to evaluate the implications of these changes. The diagnostic criteria as well as the additional remarks provided in the running text of DSM-5 were carefully appraised. For the first time diagnostic criteria are provided for disorders which up to now have been considered as subthreshold bipolar disorders. Furthermore, mixed episodes were eliminated and instead a mixed specifier was introduced. An increase in goal-directed activity/energy is now one of the obligatory symptoms for a (hypo)manic episode. Diagnostic guidance is provided as to when a (hypo)manic episode that has developed during treatment with an antidepressant has to be judged to be causally related to antidepressants and when this episode has only occurred coincidentally with antidepressant use. While some of the novelties are clearly useful, e.g. addition of increased goal-directed activity/energy as obligatory symptom for (hypo)manic episodes, this remains to be demonstrated for others, such as the definition of various subthreshold bipolar disorders.

  18. Virginia Woolf, neuroprogression, and bipolar disorder

    Directory of Open Access Journals (Sweden)

    Manuela V. Boeira

    2016-01-01

    Full Text Available Family history and traumatic experiences are factors linked to bipolar disorder. It is known that the lifetime risk of bipolar disorder in relatives of a bipolar proband are 5-10% for first degree relatives and 40-70% for monozygotic co-twins. It is also known that patients with early childhood trauma present earlier onset of bipolar disorder, increased number of manic episodes, and more suicide attempts. We have recently reported that childhood trauma partly mediates the effect of family history on bipolar disorder diagnosis. In light of these findings from the scientific literature, we reviewed the work of British writer Virginia Woolf, who allegedly suffered from bipolar disorder. Her disorder was strongly related to her family background. Moreover, Virginia Woolf was sexually molested by her half siblings for nine years. Her bipolar disorder symptoms presented a pernicious course, associated with hospitalizations, suicidal behavioral, and functional impairment. The concept of neuroprogression has been used to explain the clinical deterioration that takes places in a subgroup of bipolar disorder patients. The examination of Virgina Woolf’s biography and art can provide clinicians with important insights about the course of bipolar disorder.

  19. Bipolar Disorder and Obsessive Compulsive Disorder Comorbidity

    Directory of Open Access Journals (Sweden)

    Necla Keskin

    2014-08-01

    Full Text Available The comorbidity of bipolar disorder and anxiety disorders is a well known concept. Obsessive-compulsive disorder is the most commonly seen comorbid anxiety disorder in bipolar patients. Some genetic variants, neurotransmitters especially serotonergic systems and second-messenger systems are thought to be responsible for its etiology. Bipolar disorder alters the clinical aspects of obsessive compulsive disorder and is associated with poorer outcome. The determination of comorbidity between bipolar disorder and obsessive compulsive disorder is quite important for appropriate clinical management and treatment. [Psikiyatride Guncel Yaklasimlar - Current Approaches in Psychiatry 2014; 6(4.000: 429-437

  20. [Lithium and anticonvulsants in bipolar depression].

    Science.gov (United States)

    Samalin, L; Nourry, A; Llorca, P-M

    2011-12-01

    For decades, lithium and anticonvulsants have been widely used in the treatment of bipolar disorder. Their efficacy in the treatment of mania is recognized. These drugs have been initially evaluated in old and methodologically heterogeneous studies. Their efficacy in bipolar depression has not always been confirmed in more recent and methodologically more reliable studies. Thus, lithium's efficacy as monotherapy was challenged by the study of Young (2008) that showed a lack of efficacy compared with placebo in the treatment of bipolar depression. In two recent meta-analyses, valproate has shown a modest efficacy in the treatment of bipolar depression. As for lithium, valproate appeared to have a larger antimanic effect for acute phase and prophylaxis of bipolar disorder. In contrast, lamotrigine is more effective on the depressive pole of bipolar disorder with better evidence for the prevention of depressive recurrences. The guidelines include these recent studies and recommend lamotrigine as a first-line treatment of bipolar depression and for maintenance treatment. Because of more discordant data concerning lithium and valproate, these two drugs are placed either as first or as second line treatment of bipolar depression. The different safety/efficacy ratios of mood stabilizers underlie the complementarity and the importance of combination between them, or with some second-generation antipsychotics, in the treatment of patients with bipolar disorder. Copyright © 2011 L’Encéphale. Published by Elsevier Masson SAS.. All rights reserved.

  1. Late Onset Bipolar Disorder: Case Report

    Directory of Open Access Journals (Sweden)

    Filipa Araújo

    2016-07-01

    Full Text Available Background: Bipolar disorder affects approximately 1% of the population, with diagnosis often being made during late adolescence and early adulthood, and only rarely (0.1% in the elderly. Late onset bipolar disorder in the elderly has a impact on the nature and course of bipolar disorder. Aims: The authors report a case of bipolar disorder emerging in late life  (76years old with no cleary identified organic cause. Conclusion: This case highlights the importance of a broad differential diagnosis and pharmacologic management when approaching new-onset manic/depressive symptoms among geriatric patients.

  2. Dysfunctional gaze processing in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Cristina Berchio

    2017-01-01

    The present study provides neurophysiological evidence for abnormal gaze processing in BP and suggests dysfunctional processing of direct eye contact as a prominent characteristic of bipolar disorder.

  3. Study on the ELDRS of bipolar linear operational amplifier

    International Nuclear Information System (INIS)

    Yang Hui; Liu Yanfang; Chen Yu; Bai Hua; Zhang Dong

    2011-01-01

    Bipolar linear devices laboratory irradiation testing results are significantly different from the actual in flight exposure to the radiation. In this paper the total dose irradiation of operational amplifiers, and analysis upon the total dose response of these bipolar circuits under the different test conditions were investigated in the same experiment. Total dose tests of bipolar linear operational amplifiers show susceptible to dose rate, bias and room temperature annealing during exposure. The critical sensitive parameters of operational amplifier are input bias current, input offset current, input offset voltage, and open loop gain, which exhibits both bias and dose rate dependence. With calculating the change of each electrical parameter (Δpara) for each sample at 300 Gy radiation level, it has been found that ratio of the Δpara at low dose rate to the Δpara at high dose rate exceeds 2.46 times for any of the parameters. So these parts are considered to be ELDRS susceptible. After room temperature annealing, the main parameters have time dependence effect at low dose rate and without time dependent effect at high dose rate. (authors)

  4. Radiofrequency electromagnetic radiation from cell phone causes defective testicular function in male Wistar rats.

    Science.gov (United States)

    Oyewopo, A O; Olaniyi, S K; Oyewopo, C I; Jimoh, A T

    2017-12-01

    Cell phones have become an integral part of everyday life. As cell phone usage has become more widespread, concerns have increased regarding the harmful effects of radiofrequency electromagnetic radiation from these devices. The current study was undertaken to investigate the effects of the emitted radiation by cell phones on testicular histomorphometry and biochemical analyses. Adult male Wistar rats weighing 180-200 g were randomly allotted to control, group A (switched off mode exposure), group B (1-hr exposure), group C (2-hr exposure) and group D (3-hr exposure). The animals were exposed to radiofrequency electromagnetic radiation of cell phone for a period of 28 days. Histomorphometry, biochemical and histological investigations were carried out. The histomorphometric parameters showed no significant change (p electromagnetic radiation of cell phone leads to defective testicular function that is associated with increased oxidative stress and decreased gonadotropic hormonal profile. © 2017 Blackwell Verlag GmbH.

  5. Bipolar mixed features - Results from the comparative effectiveness for bipolar disorder (Bipolar CHOICE) study.

    Science.gov (United States)

    Tohen, Mauricio; Gold, Alexandra K; Sylvia, Louisa G; Montana, Rebecca E; McElroy, Susan L; Thase, Michael E; Rabideau, Dustin J; Nierenberg, Andrew A; Reilly-Harrington, Noreen A; Friedman, Edward S; Shelton, Richard C; Bowden, Charles L; Singh, Vivek; Deckersbach, Thilo; Ketter, Terence A; Calabrese, Joseph R; Bobo, William V; McInnis, Melvin G

    2017-08-01

    DSM-5 changed the criteria from DSM-IV for mixed features in mood disorder episodes to include non-overlapping symptoms of depression and hypomania/mania. It is unknown if, by changing these criteria, the same group would qualify for mixed features. We assessed how those meeting DSM-5 criteria for mixed features compare to those meeting DSM-IV criteria. We analyzed data from 482 adult bipolar patients in Bipolar CHOICE, a randomized comparative effectiveness trial. Bipolar diagnoses were confirmed through the MINI International Neuropsychiatric Interview (MINI). Presence and severity of mood symptoms were collected with the Bipolar Inventory of Symptoms Scale (BISS) and linked to DSM-5 and DSM-IV mixed features criteria. Baseline demographics and clinical variables were compared between mood episode groups using ANOVA for continuous variables and chi-square tests for categorical variables. At baseline, the frequency of DSM-IV mixed episodes diagnoses obtained with the MINI was 17% and with the BISS was 20%. Using DSM-5 criteria, 9% of participants met criteria for hypomania/mania with mixed features and 12% met criteria for a depressive episode with mixed features. Symptom severity was also associated with increased mixed features with a high rate of mixed features in patients with mania/hypomania (63.8%) relative to those with depression (8.0%). Data on mixed features were collected at baseline only and thus do not reflect potential patterns in mixed features within this sample across the study duration. The DSM-5 narrower, non-overlapping definition of mixed episodes resulted in fewer patients who met mixed criteria compared to DSM-IV. Copyright © 2017. Published by Elsevier B.V.

  6. Endovascular Radiofrequency Ablation for Varicose Veins

    Science.gov (United States)

    2011-01-01

    treatment plan. The RFA procedure involves the introduction of a guide wire into the target vein under ultrasound guidance followed by the insertion of an introducer sheath through which the RFA catheter is advanced. Once satisfactory positioning has been confirmed with ultrasound, a tumescent anaesthetic solution is injected into the soft tissue surrounding the target vein along its entire length. This serves to anaesthetize the vein, insulate the heat from damaging adjacent structures, including nerves and skin and compresses the vein increasing optimal contact of the vessel wall with the electrodes or expanded prongs of the RF device. The RF generator is then activated and the catheter is slowly pulled along the length of the vein. At the end of the procedure, hemostasis is then achieved by applying pressure to the vein entry point. Adequate and proper compression stockings and bandages are applied after the procedure to reduce the risk of venous thromboembolism and to reduce postoperative bruising and tenderness. Patients are encouraged to walk immediately after the procedure. Follow-up protocols vary, with most patients returning 1 to 3 weeks later for an initial follow-up visit. At this point, the initial clinical result is assessed and occlusion of the treated vessels is confirmed with ultrasound. Patients often have a second follow-up visit 1 to 3 months following RFA at which time clinical evaluation and ultrasound are repeated. If required, additional procedures such as phlebectomy or sclerotherapy may be performed during the RFA procedure or at any follow-up visits. Regulatory Status The Closure System® radiofrequency generator for endovascular thermal ablation of varicose veins was approved by Health Canada as a class 3 device in March 2005, registered under medical device license 67865. The RFA intravascular catheter was approved by Health Canada in November 2007 for the ClosureFast catheter, registered under medical device license 16574. The Closure System

  7. Radiofrequency and health. Expertise update. Opinion of the ANSES. Collective expertise report

    International Nuclear Information System (INIS)

    Cardis, Elisabeth; Dore, Jean-Francois; Marc-Vergnes, Jean-Pierre; Agnani, Jean-Benoit; Bruguiere, Pierre; Crouzier, David; Debaz, Josquin; Debuire, Brigitte; Deltour, Isabelle; LE Drean, Yves; Ledoigt, Gerard; Letertre, Thierry; Marchand, Dorothee; Massardier-Pilonchery, Amelie; Nadi, Mustapha; Pereira De Vasconcelos, Anne; Hours, Martine; Fite, Johanna; Merckel, Olivier; Roth, Olivia; Vergriette, Benoit; Saddoki, Sophia

    2013-10-01

    In a context of development of new technologies of wireless communications, and therefore of radio-electric signals used to transmit information, this voluminous document reports a detailed study on the effects of radiofrequency on health. It is notably based on a large literature survey and on an assessment of the level of proof of these effects by experts (proved, possible, probable, insufficiently proved, or no effect on mankind). These effects can be either biological or on health. The report presents the context, scope and modalities of the expertise study, presents the main artificial and natural sources of radiofrequency radiation, gives a detailed presentation of new exposure sources (new signals, new radio-electric networks and their applications like mobile phones, pads, mobile television, local wireless networks, RFID, so on). It describes metrology and dose measurement techniques for electromagnetic fields (exposure characterization in laboratory, characterization of the electromagnetic environment, individual exposure measurement devices, digital dosimetry). It addresses the efficiency of anti-wave devices. The next part presents the literature survey (method, analysis, results). The authors then report an assessment of the risk level related to radio-frequencies for the central nervous system (neurotoxicity mechanisms, cognitive functions, memory and behaviour, sleep and circadian rhythms, hearing functions, neurological and neuro-degenerative diseases), and an assessment of the risk level of radio-frequencies for other non-carcinogenic effects (possible mechanisms, reproduction, immunology, endocrine system, and so on). They discuss the researches on potential carcinogenic mechanisms. They give an overview of the evolutions of regulations and management measures in France, and propose a set of recommendations

  8. Single-event burnout of power bipolar junction transistors

    International Nuclear Information System (INIS)

    Titus, J.L.; Johnson, G.H.; Schrimpf, R.D.; Galloway, K.F.

    1991-01-01

    Experimental evidence of single-event burnout of power bipolar junctions transistors (BJTs) is reported for the first time. Several commercial power BJTs were characterized in a simulated cosmic ray environment using mono-energetic ions at the tandem Van de Graaff accelerator facility at Brookhaven National Laboratory. Most of the device types exposed to this simulated environment exhibited burnout behavior. In this paper the experimental technique, data, and results are presented, while a qualitative model is used to help explain those results and trends observed in this experiment

  9. Corrosion of metal bipolar plates for PEM fuel cells: A review

    Energy Technology Data Exchange (ETDEWEB)

    Antunes, Renato A. [Engenharia de Materiais, Universidade Federal do ABC (UFABC), 09210-170 Santo Andre, SP (Brazil); Oliveira, Mara Cristina L.; Ett, Gerhard; Ett, Volkmar [Electrocell Ind. Com. Equip. Elet. LTDA, Centro de Inovacao, Empreendedorismo e Tecnologia (CIETEC), 05508-000 Sao Paulo, SP (Brazil)

    2010-04-15

    PEM fuel cells are of prime interest in transportation applications due to their relatively high efficiency and low pollutant emissions. Bipolar plates are the key components of these devices as they account for significant fractions of their weight and cost. Metallic materials have advantages over graphite-based ones because of their higher mechanical strength and better electrical conductivity. However, corrosion resistance is a major concern that remains to be solved as metals may develop oxide layers that increase electrical resistivity, thus lowering the fuel cell efficiency. This paper aims to present the main results found in recent literature about the corrosion performance of metallic bipolar plates. (author)

  10. Arthroscopic surgery using radio-frequency electrocautery

    International Nuclear Information System (INIS)

    Takatsuka, Shigeyuki; Yoshida, Kan; Nakagawa, Kiyomasa; Yamamoto, Etsuhide; Kubota, Yoshiyuki; Narinobou, Masayoshi; Terai, Koichi; Hasegawa, Hiroshi

    2008-01-01

    Arthroscopic surgery using radio-frequency electrocautery was carried out on 23 temporomandibular joints (TMJs) in 13 patients. Because these patients did not respond to conservative therapy, surgery was indicated. Preoperative MRI showed anterior disc displacement without reduction in all patients. Disturbed translation was also recognized in all of the discs and mandibular condyles. Intraoperative arthroscopic examination showed severe fibrous adhesion in the upper joint compartment and disc displacement. Four joints showed perforation between the disc and retrodiscal tissue. Postoperative findings included an increased range of vertical maximal mouth opening and decreased pain on mandibular movement. Analyses of postoperative MRI indicated recovery of disc and condylar translation. These results suggested that the introduction of arthroscopic surgery using radiofrequency electrocautery would significantly reduce the number of patients with osteoarthritic TMJ disorders. (author)

  11. Temperature-controlled irrigated tip radiofrequency catheter ablation

    DEFF Research Database (Denmark)

    Petersen, H H; Chen, X; Pietersen, Adrian

    1998-01-01

    INTRODUCTION: In patients with ventricular tachycardias due to structural heart disease, catheter ablation cures radiofrequency ablation. Irrigated tip radiofrequency ablation using power control and high infusion rates enlarges lesion......: We conclude that temperature-controlled radiofrequency ablation with irrigated tip catheters using low target temperature and low infusion rate enlarges lesion size without increasing the incidence of cratering and reduces coagulum formation of the tip....

  12. Transient Stuttering in Catatonic Bipolar Patients

    Directory of Open Access Journals (Sweden)

    Anthony B. Joseph

    1991-01-01

    Full Text Available Two cases of transient stuttering occurring in association with catatonia and bipolar disorder are described. Affective decompensation has been associated with lateralized cerebral dysfunction, and it is hypothesized that in some bipolar catatonic patients a concomitant disorder of the lateralization of language function may lead to a variety of clinical presentations including aphasia, mutism, and stuttering.

  13. Swimming in Deep Water: Childhood Bipolar Disorder

    Science.gov (United States)

    Senokossoff, Gwyn W.; Stoddard, Kim

    2009-01-01

    The authors focused on one parent's struggles in finding a diagnosis and intervention for a child who had bipolar disorder. The authors explain the process of identification, diagnosis, and intervention of a child who had bipolar disorder. In addition to the personal story, the authors provide information on the disorder and outline strategies…

  14. Bipolar disorder diagnosis: challenges and future directions

    Science.gov (United States)

    Phillips, Mary L; Kupfer, David J

    2018-01-01

    Bipolar disorder refers to a group of affective disorders, which together are characterised by depressive and manic or hypomanic episodes. These disorders include: bipolar disorder type I (depressive and manic episodes: this disorder can be diagnosed on the basis of one manic episode); bipolar disorder type II (depressive and hypomanic episodes); cyclothymic disorder (hypomanic and depressive symptoms that do not meet criteria for depressive episodes); and bipolar disorder not otherwise specified (depressive and hypomanic-like symptoms that do not meet the diagnostic criteria for any of the aforementioned disorders). Bipolar disorder type II is especially difficult to diagnose accurately because of the difficulty in differentiation of this disorder from recurrent unipolar depression (recurrent depressive episodes) in depressed patients. The identification of objective biomarkers that represent pathophysiologic processes that differ between bipolar disorder and unipolar depression can both inform bipolar disorder diagnosis and provide biological targets for the development of new and personalised treatments. Neuroimaging studies could help the identification of biomarkers that differentiate bipolar disorder from unipolar depression, but the problem in detection of a clear boundary between these disorders suggests that they might be better represented as a continuum of affective disorders. Innovative combinations of neuroimaging and pattern recognition approaches can identify individual patterns of neural structure and function that accurately ascertain where a patient might lie on a behavioural scale. Ultimately, an integrative approach, with several biological measurements using different scales, could yield patterns of biomarkers (biosignatures) to help identify biological targets for personalised and new treatments for all affective disorders. PMID:23663952

  15. Bipolar Disorder and Cognitive Therapy: A Commentary

    Science.gov (United States)

    Riskind, John H.

    2005-01-01

    This article comments on the three articles (Leahy, 2005; Newman, 2005; and Reilly-Harrington & Knauz, 2005) that deal with the applications of cognitive therapy to treatment of bipolar disorder. They focus on the uses of cognitive therapy in treating three important facets of the special problems of bipolar patients: rapid cycling, severe…

  16. Perceived parental rearing of bipolar offspring

    NARCIS (Netherlands)

    Reichart, C. G.; van der Ende, J.; Hillegers, M. H. J.; Wals, M.; Bongers, I. L.; Nolen, W. A.; Ormel, J.; Verhulst, F. C.

    Objective: To explore the impact of growing up with a parent with a bipolar disorder. First, we compared parental rearing behavior perceived by young adult offspring of bipolar parents with parental rearing behavior perceived by same aged young adults from the general population. Secondly, we

  17. Cognitive behavioral therapy for bipolar disorders

    OpenAIRE

    Lotufo Neto, Francisco

    2004-01-01

    Descrição dos objetivos e principais técnicas da terapia comportamental cognitiva usadas para a psicoterapia das pessoas com transtorno bipolar.Objectives and main techniques of cognitive behavior therapy for the treatment of bipolar disorder patients are described.

  18. Effect of Radiofrequency Endometrial Ablation on Dysmenorrhea.

    Science.gov (United States)

    Wyatt, Sabrina N; Banahan, Taylor; Tang, Ying; Nadendla, Kavita; Szychowski, Jeff M; Jenkins, Todd R

    To examine rates of dysmenorrhea after radiofrequency endometrial ablation in patients with and without known dysmenorrhea symptoms prior to the procedure in a diverse population. Retrospective cohort study (Canadian Task Force classification II-2). Academic gynecology practice. A total of 307 women underwent endometrial ablation between 2007 and 2013 at our institution. Patients who had preoperative and postoperative pain symptom assessments as well as a description of pain timing recorded were included in our analysis. Exclusion criteria were age dysmenorrhea was evaluated. Demographic information and other outcome variables were used to evaluate factors associated with resolution of dysmenorrhea. A total of 307 patients who underwent radiofrequency endometrial ablation were identified. After exclusions, 296 charts were examined, and 144 patients met our enrollment criteria. The mean age of the study cohort was 45.4 ± 6.2 years; 57 patients (40%) were African American, 16 (11%) had a body mass index (BMI) > 40, and 41 (29%) were of normal weight. Preoperative dysmenorrhea was reported by 100 patients (69%); 48 of these patients (48%) experienced resolution of symptoms postoperatively. Only 3 of the 44 patients (7%) without preoperative dysmenorrhea reported new-onset dysmenorrhea postoperatively. Significantly fewer patients had dysmenorrhea after compared to before radiofrequency ablation (55 of 144 [38%] vs 100 of 144 [69%]; p dysmenorrhea after ablation was associated with reduction in bleeding volume (p = .048) but not with a reduction in frequency of bleeding (p = .12). Approximately one-half of women who undergo radiofrequency endometrial ablation to treat heavy menstrual bleeding who also have preoperative dysmenorrhea exhibit documented pain resolution after the procedure. Resolution of dysmenorrhea is more likely if menstrual flow volume is decreased postprocedure. Copyright © 2016 AAGL. Published by Elsevier Inc. All rights reserved.

  19. Radiofrequency Wire Recanalization of Chronically Thrombosed TIPS

    Energy Technology Data Exchange (ETDEWEB)

    Majdalany, Bill S., E-mail: bmajdala@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States); Elliott, Eric D., E-mail: eric.elliott@osumc.edu [The Ohio State University Wexner Medical Center, Division of Interventional Radiology, Department of Radiology (United States); Michaels, Anthony J., E-mail: Anthony.michaels@osumc.edu; Hanje, A. James, E-mail: James.Hanje@osumc.edu [The Ohio State University Wexner Medical Center, Division of Gastroenterology and Hepatology, Department of Medicine (United States); Saad, Wael E. A., E-mail: wsaad@med.umich.edu [University of Michigan Health System, Division of Interventional Radiology, Department of Radiology (United States)

    2016-07-15

    Radiofrequency (RF) guide wires have been applied to cardiac interventions, recanalization of central venous thromboses, and to cross biliary occlusions. Herein, the use of a RF wire technique to revise chronically occluded transjugular intrahepatic portosystemic shunts (TIPS) is described. In both cases, conventional TIPS revision techniques failed to revise the chronically thrombosed TIPS. RF wire recanalization was successfully performed through each of the chronically thrombosed TIPS, demonstrating initial safety and feasibility in this application.

  20. Issues in epidemiological studies of radiofrequency workers

    International Nuclear Information System (INIS)

    Hocking, B.

    1985-01-01

    The paper reviews some of the issues in a proposed epidemiological study of radiofrequency workers. First a few other epidemiological studies are discussed to illustrate some of the common problems such as inadequate definition of effects and/or exposure. Then technical problems in determining dosage and responses as well as study design are reviewed, and finally the administrative aspects of ethics, industrial relations and costs are considered

  1. ROLE OF RADIOFREQUENCY ABLATION IN ADENOMA SEBACEUM

    Directory of Open Access Journals (Sweden)

    Ch. Madh

    2016-03-01

    Full Text Available Adenoma sebaceum, pathognomonic of tuberous sclerosis, are tiny angiofibromas which commonly occur over central part of face. Recurrence after treatment is common and hence a need for inexpensive, safe and efficient treatment is required. Radiofrequency ablation is a safe and an economical procedure and has been known to cause less scarring with good aesthetic results compared to other ablative methods such as electrocautery.

  2. 2017 Bipolar Plate Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Kopasz, John P. [Argonne National Lab. (ANL), Argonne, IL (United States); Benjamin, Thomas G. [Argonne National Lab. (ANL), Argonne, IL (United States); Schenck, Deanna [Argonne National Lab. (ANL), Argonne, IL (United States)

    2017-08-17

    The Bipolar Plate (BP) Workshop was held at USCAR1 in Southfield, Michigan on February 14, 2017 and included 63 participants from industry, government agencies, universities, and national laboratories with expertise in the relevant fields. The objective of the workshop was to identify research and development (R&D) needs, in particular early-stage R&D, for bipolar plates for polymer electrolyte membrane (PEM) fuel cells for transportation applications. The focus of the workshop was on materials, manufacturing, and design aspects of bipolar plates with the goal of meeting DOE’s 2020 bipolar plate targets. Of special interest was the cost target of ≤$3/kW for the bipolar plate.

  3. Total dose and dose rate models for bipolar transistors in circuit simulation.

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Phillip Montgomery; Wix, Steven D.

    2013-05-01

    The objective of this work is to develop a model for total dose effects in bipolar junction transistors for use in circuit simulation. The components of the model are an electrical model of device performance that includes the effects of trapped charge on device behavior, and a model that calculates the trapped charge densities in a specific device structure as a function of radiation dose and dose rate. Simulations based on this model are found to agree well with measurements on a number of devices for which data are available.

  4. Personal radiofrequency electromagnetic field exposure measurements in Swiss adolescents.

    Science.gov (United States)

    Roser, Katharina; Schoeni, Anna; Struchen, Benjamin; Zahner, Marco; Eeftens, Marloes; Fröhlich, Jürg; Röösli, Martin

    2017-02-01

    Adolescents belong to the heaviest users of wireless communication devices, but little is known about their personal exposure to radiofrequency electromagnetic fields (RF-EMF). The aim of this paper is to describe personal RF-EMF exposure of Swiss adolescents and evaluate exposure relevant factors. Furthermore, personal measurements were used to estimate average contributions of various sources to the total absorbed RF-EMF dose of the brain and the whole body. Personal exposure was measured using a portable RF-EMF measurement device (ExpoM-RF) measuring 13 frequency bands ranging from 470 to 3600MHz. The participants carried the device for three consecutive days and kept a time-activity diary. In total, 90 adolescents aged 13 to 17years participated in the study conducted between May 2013 and April 2014. In addition, personal measurement values were combined with dose calculations for the use of wireless communication devices to quantify the contribution of various RF-EMF sources to the daily RF-EMF dose of adolescents. Main contributors to the total personal RF-EMF measurements of 63.2μW/m 2 (0.15V/m) were exposures from mobile phones (67.2%) and from mobile phone base stations (19.8%). WLAN at school and at home had little impact on the personal measurements (WLAN accounted for 3.5% of total personal measurements). According to the dose calculations, exposure from environmental sources (broadcast transmitters, mobile phone base stations, cordless phone base stations, WLAN access points, and mobile phones in the surroundings) contributed on average 6.0% to the brain dose and 9.0% to the whole-body dose. RF-EMF exposure of adolescents is dominated by their own mobile phone use. Environmental sources such as mobile phone base stations play a minor role. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Development of three channel linear bipolar high voltage amplifier (±2 KV) for electrostatic steerer

    International Nuclear Information System (INIS)

    Rajesh Kumar; Mukesh Kumar; Suman, S.K.; Safvan, C.P.; Mandal, A.

    2011-01-01

    Electrostatic steerers and scanners are planned for low energy ion beam facilities at IUAC to steer and scan the ion beam on target. The power supplies for electrostatic steerers are high voltage bipolar DC amplifiers and for scanners are bipolar AC amplifiers. To fulfil the requirements a common unit has been designed and assembled for AC and DC applications. It can be used with electrostatic devices in scanning, steering and sweeping of low energy ion beams at high frequencies to attain uniform implantation. The unit consist of three independent limited bandwidth high voltage, linear bipolar amplifiers (for X-axis, Y-axis and Y1-dog leg plates). The unit has been provided with both local and remote control. (author)

  6. Bipolarly stacked electrolyser for energy and space efficient fabrication of supercapacitor electrodes

    Science.gov (United States)

    Liu, Xiaojuan; Wu, Tao; Dai, Zengxin; Tao, Keran; Shi, Yong; Peng, Chuang; Zhou, Xiaohang; Chen, George Z.

    2016-03-01

    Stacked electrolysers with titanium bipolar plates are constructed for electrodeposition of polypyrrole electrodes for supercapacitors. The cathode side of the bipolar Ti plates are pre-coated with activated carbon. In this new design, half electrolysis occurs which significantly lowers the deposition voltage. The deposited electrodes are tested in a symmetrical unit cell supercapacitor and an asymmetrical supercapacitor stack. Both devices show excellent energy storage performances and the capacitance values are very close to the design value, suggesting a very high current efficiency during the electrodeposition. The electrolyser stack offers multi-fold benefits for preparation of conducting polymer electrodes, i.e. low energy consumption, facile control of the electrode capacitance and simultaneous preparation of a number of identical electrodes. Therefore, the stacked bipolar electrolyser is a technology advance that offers an engineering solution for mass production of electrodeposited conducting polymer electrodes for supercapacitors.

  7. Radiofrequency initiation and radiofrequency sustainment of laser initiated seeded high pressure plasma

    International Nuclear Information System (INIS)

    Paller, Eric S.; Scharer, John E.; Akhtar, Kamran; Kelly, Kurt; Ding, Guowen

    2001-01-01

    We examine radiofrequency initiation of high pressure(1-70 Torr) inductive plasma discharges in argon, nitrogen, air and organic seed gas mixtures. Millimeter wave interferometry, optical emission and antenna wave impedance measurements for double half-turn helix and helical inductive antennas are used to interpret the rf/plasma coupling, measure the densities in the range of 10 12 cm -3 and analyze the ionization and excited states of the gas mixtures. We have also carried out 193 nm excimer laser initiation of an organic gas seed plasma which is sustained at higher pressures(150 Torr) by radiofrequency coupling at 2.8 kW power levels

  8. Bipolar disorder and related mood states are not associated with endothelial function of small arteries in adults without heart disease.

    Science.gov (United States)

    Tong, Brian; Abosi, Oluchi; Schmitz, Samantha; Myers, Janie; Pierce, Gary L; Fiedorowicz, Jess G

    Individuals with bipolar disorder are at increased risk for adverse cardiovascular disease (CVD) events. This study aimed to assess endothelial function and wave reflection, a risk factor for CVD, as measured by finger plethysmography in bipolar disorder to investigate whether CVD risk was higher in bipolar disorder and altered during acute mood episodes. We hypothesized that EndoPAT would detect a lower reactive hyperemia index (RHI) and higher augmentation index (AIX) in individuals with bipolar disorder compared with controls. Second, we predicted lower RHI and higher AIX during acute mood episodes. Reactive hyperemia index and augmentation index, measures of microvascular endothelial function and arterial pressure wave reflection respectively, were assessed using the EndoPAT 2000 device in a sample of 56 participants with a DSM-IV diagnosis of bipolar I disorder with 82 measures spanning different mood states (mania, depression, euthymia) and cross-sectionally in 26 healthy controls. RHI and AIX were not different between adults with and without bipolar disorder (mean age 40.3 vs. 41.2years; RHI: 2.04±0.67 vs. 2.05±0.51; AIX@75 (AIX adjusted for heart rate of 75): 1.4±19.7 vs. 0.8±22.4). When modeled in linear mixed models with a random intercept (to account for repeated observations of persons with bipolar disorder) and adjusting for age and sex, there were no significant differences between those with bipolar disorder and controls (p=0.89 for RHI; p=0.85 for AIX@75). Microvascular endothelial function and wave reflection estimated by finger plethysmography were unable to detect differences between adults with and without bipolar disorder or changes with mood states. Future research is necessary to identify more proximal and sensitive, yet relevant, biomarkers of abnormal mood-related influences on CVD risk or must target higher risk samples. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Fabrication of carbon-polymer composite bipolar plates for polymer electrolyte membrane fuel cells by compression moulding

    International Nuclear Information System (INIS)

    Raza, M.A.; Ahmed, R.; Saleem, A.; Din, R.U.

    2009-01-01

    Fuel cells are considered as one of the most important technologies to address the future energy and environmental pollution problems. These are the most promising power sources for road transportation and portable devices. A fuel cell is an electrochemical device that converts chemical energy into electrical energy. A fuel cell stack consists of bipolar plates and membrane electrode assemblies (MEA). The bipolar plate is by weight, volume and cost one of the most significant components of a fuel cell stack. Major functions of bipolar plates are to separate oxidant and fuel gas, provide flow channels, conduct electricity and provide heat transfer. Bipolar plates can be made from various materials including graphite, metals, carbon / carbon and carbon/ polymer composites. Materials for carbon-polymer composites are relatively inexpensive, less corrosive, strong and channels can be formed by means of a moulding process. Carbon-polymer composites are of two type i.e; thermosetting and thermoplastic. For thermosetting composite a bulk molding compound (BMC) was prepared by adding graphite, vinyl ester resin, methyl ethyl ketone peroxide and cobalt naphthalate. The BMC was thoroughly mixed, poured into a die mould of a bipolar plate with channels and hot pressed at a specific temperature and pressure. A bipolar plate was formed according to the die mould. Design of the mould is also discussed. Conducting polymers were also added to BMC to increase the conductivity of bipolar plates. Particle size of the graphite has also a significant effect on the conductivity of the bipolar plates. Thermoplastic composites were also prepared using polypropylene and graphite.

  10. DeepBipolar: Identifying genomic mutations for bipolar disorder via deep learning.

    Science.gov (United States)

    Laksshman, Sundaram; Bhat, Rajendra Rana; Viswanath, Vivek; Li, Xiaolin

    2017-09-01

    Bipolar disorder, also known as manic depression, is a brain disorder that affects the brain structure of a patient. It results in extreme mood swings, severe states of depression, and overexcitement simultaneously. It is estimated that roughly 3% of the population of the United States (about 5.3 million adults) suffers from bipolar disorder. Recent research efforts like the Twin studies have demonstrated a high heritability factor for the disorder, making genomics a viable alternative for detecting and treating bipolar disorder, in addition to the conventional lengthy and costly postsymptom clinical diagnosis. Motivated by this study, leveraging several emerging deep learning algorithms, we design an end-to-end deep learning architecture (called DeepBipolar) to predict bipolar disorder based on limited genomic data. DeepBipolar adopts the Deep Convolutional Neural Network (DCNN) architecture that automatically extracts features from genotype information to predict the bipolar phenotype. We participated in the Critical Assessment of Genome Interpretation (CAGI) bipolar disorder challenge and DeepBipolar was considered the most successful by the independent assessor. In this work, we thoroughly evaluate the performance of DeepBipolar and analyze the type of signals we believe could have affected the classifier in distinguishing the case samples from the control set. © 2017 Wiley Periodicals, Inc.

  11. A YinYang bipolar fuzzy cognitive TOPSIS method to bipolar disorder diagnosis.

    Science.gov (United States)

    Han, Ying; Lu, Zhenyu; Du, Zhenguang; Luo, Qi; Chen, Sheng

    2018-05-01

    Bipolar disorder is often mis-diagnosed as unipolar depression in the clinical diagnosis. The main reason is that, different from other diseases, bipolarity is the norm rather than exception in bipolar disorder diagnosis. YinYang bipolar fuzzy set captures bipolarity and has been successfully used to construct a unified inference mathematical modeling method to bipolar disorder clinical diagnosis. Nevertheless, symptoms and their interrelationships are not considered in the existing method, circumventing its ability to describe complexity of bipolar disorder. Thus, in this paper, a YinYang bipolar fuzzy multi-criteria group decision making method to bipolar disorder clinical diagnosis is developed. Comparing with the existing method, the new one is more comprehensive. The merits of the new method are listed as follows: First of all, multi-criteria group decision making method is introduced into bipolar disorder diagnosis for considering different symptoms and multiple doctors' opinions. Secondly, the discreet diagnosis principle is adopted by the revised TOPSIS method. Last but not the least, YinYang bipolar fuzzy cognitive map is provided for the understanding of interrelations among symptoms. The illustrated case demonstrates the feasibility, validity, and necessity of the theoretical results obtained. Moreover, the comparison analysis demonstrates that the diagnosis result is more accurate, when interrelations about symptoms are considered in the proposed method. In a conclusion, the main contribution of this paper is to provide a comprehensive mathematical approach to improve the accuracy of bipolar disorder clinical diagnosis, in which both bipolarity and complexity are considered. Copyright © 2018 Elsevier B.V. All rights reserved.

  12. Giant magneto-resistance devices

    CERN Document Server

    Hirota, Eiichi; Inomata, Koichiro

    2002-01-01

    This book deals with the application of giant magneto-resistance (GMR) effects to electronic devices. It will appeal to engineers and graduate students in the fields of electronic devices and materials. The main subjects are magnetic sensors with high resolution and magnetic read heads with high sensitivity, required for hard-disk drives with recording densities of several gigabytes. Another important subject is novel magnetic random-access memories (MRAM) with non-volatile non-destructive and radiation-resistant characteristics. Other topics include future GMR devices based on bipolar spin transistors, spin field-effect transistors (FETs) and double-tunnel junctions.

  13. Radiofrequency identification: exploiting an old technology for measuring nurse time and motion.

    Science.gov (United States)

    Jones, Terry L

    2012-09-01

    A national campaign is underway to increase the amount of time staff nurses spend at the bedside of hospitalized patients through redesign of the work environment. This kind of work redesign requires robust data depicting what nurses do and how they spend their time. Historically, these kinds of data have been difficult, costly, and time consuming to collect. Wireless capture of data on the movement of humans within the work environment (ie, time and motion) is now possible through radiofrequency identification technology. When small tracking devices the size of a quarter are affixed to their clothing, the movement of nurses throughout a patient care unit can be monitored. The duration and frequency of patient interaction are captured along with the duration of time spent in other locations of interest to include nurses' station, supply room, medication room, doctors' station, electronic documentation stations, family waiting rooms, and the hallway. Patterns of nurse movement and time allocation can be efficiently identified, and the effects of staffing practices, workflows, and unit layout evaluated. Integration of radiofrequency identification time and motion data with other databases enables nurse leaders to link nursing time to important cost and quality outcomes. Nurse leaders should explore the usefulness of radiofrequency identification technology in addressing data needs for nurse time and motion.

  14. Lower switch rate in depressed patients with bipolar II than bipolar I disorder treated adjunctively with second-generation antidepressants

    NARCIS (Netherlands)

    Altshuler, LL; Suppes, T; Nolen, WA; Leverich, G; Keck, PE; Frye, MA; Kupka, R; McElroy, SL; Grunze, H; Kitchen, CMR; Post, R; Black, D.O.

    Objectives: The authors compared the switch rate into hypomania/mania in depressed patients treated with second-generation antidepressants who had either bipolar I or bipolar II disorder. Method: In a 10-week trial, 184 outpatients with bipolar depression (134 with bipolar I disorder, 48 with

  15. Brief Report: A Family Risk Study Exploring Bipolar Spectrum Problems and Cognitive Biases in Adolescent Children of Bipolar Parents

    Science.gov (United States)

    Espie, Jonathan; Jones, Steven H.; Vance, Yvonne H.; Tai, Sara J.

    2012-01-01

    Children of parents with bipolar disorder are at increased risk of bipolar spectrum diagnoses. This cross-sectional study explores cognitive factors in the prediction of vulnerability to bipolar disorder. Adolescents at high-risk (with a parent with bipolar disorder; n = 23) and age and gender matched adolescents (n = 24) were recruited. Parent…

  16. Bipolar spintronics: from spin injection to spin-controlled logic

    International Nuclear Information System (INIS)

    Zutic, Igor; Fabian, Jaroslav; Erwin, Steven C

    2007-01-01

    An impressive success of spintronic applications has been typically realized in metal-based structures which utilize magnetoresistive effects for substantial improvements in the performance of computer hard drives and magnetic random access memories. Correspondingly, the theoretical understanding of spin-polarized transport is usually limited to a metallic regime in a linear response, which, while providing a good description for data storage and magnetic memory devices, is not sufficient for signal processing and digital logic. In contrast, much less is known about possible applications of semiconductor-based spintronics and spin-polarized transport in related structures which could utilize strong intrinsic nonlinearities in current-voltage characteristics to implement spin-based logic. Here we discuss the challenges for realizing a particular class of structures in semiconductor spintronics: our proposal for bipolar spintronic devices in which carriers of both polarities (electrons and holes) contribute to spin-charge coupling. We formulate the theoretical framework for bipolar spin-polarized transport, and describe several novel effects in two- and three-terminal structures which arise from the interplay between nonequilibrium spin and equilibrium magnetization

  17. VALPROATE, BIPOLAR DISORDER AND POLYCYSTIC OVARIAN SYNDROME.

    Science.gov (United States)

    Okanović, Milana; Zivanović, Olga

    2016-01-01

    Polycystic ovarian syndrome is a syndrome of ovarian dysfunction with the principal features of hyperandrogenism and polycystic ovary morphology. A large number of studies conducted on this topic have suggested a possible role of anticonvulsants, particularly valproate, in the pathogenesis or risk factors associated with polycystic ovarian syndrome. Bipolar treatment guidelines from Canada and the United States of America recommend valproate as the first line strategy in the acute treatment of bipolar disorder. Most persons with bipolar disorder require maintenance treatment. Long-term administration of valproate in women with bipolar disorder or epilepsy is believed to result in the increased risk of hyperandrogenism, menstrual abnormalities and polycystic ovaries. Valproate may also increase the risk of infertility and other associated symptoms of polycystic ovarian syndrome. Therefore, particular caution is indicated in the use of valproate in women of reproductive age. The treatment of the female patients with bipolar disorder presents various challenges for the clinician. Every woman of reproductive age needs to know the risk and benefits of her pharmacologic treatment options. Bipolar disorder should be considered chronic disorder, whose development is largely affected by hormonal changes and reproductive cycle in women. These issues should be researched more thoroughly in order to opt for the most appropriate treatment in women with bipolar disorder.

  18. Bipolar plates for PEM fuel cells

    Science.gov (United States)

    Middelman, E.; Kout, W.; Vogelaar, B.; Lenssen, J.; de Waal, E.

    The bipolar plates are in weight and volume the major part of the PEM fuel cell stack, and are also a significant contributor to the stack costs. The bipolar plate is therefore a key component if power density has to increase and costs must come down. Three cell plate technologies are expected to reach targeted cost price levels, all having specific advantages and drawbacks. NedStack has developed a conductive composite materials and a production process for fuel cell plates (bipolar and mono-polar). The material has a high electric and thermal conductivity, and can be processed into bipolar plates by a proprietary molding process. Process cycle time has been reduced to less than 10 s, making the material and process suitable for economical mass production. Other development work to increase material efficiency resulted in thin bipolar plates with integrated cooling channels, and integrated seals, and in two-component bipolar plates. Total thickness of the bipolar plates is now less than 3 mm, and will be reduced to 2 mm in the near future. With these thin integrated plates it is possible to increase power density up to 2 kW/l and 2 kW/kg, while at the same time reducing cost by integrating other functions and less material use.

  19. Distinctions of bipolar disorder symptoms in adolescence.

    Science.gov (United States)

    Gudiene, Devika; Leskauskas, Darius; Markeviciūte, Aurelija; Klimavicius, Dalius; Adomaitiene, Virginija

    2008-01-01

    Bipolar disorder in adolescents is a serious mental illness with problematic diagnosis that adversely affects social, academic, emotional, and family functioning. The objective of this study was to analyze features of premorbid and clinical symptoms, comorbidity, and course of bipolar disorder in adolescence. Data for analysis were collected from all case histories (N=6) of 14-18-year-old patients, hospitalized with diagnosis of bipolar disorder in the Unit of Children's and Adolescents' Psychiatry, Department of Psychiatry, Hospital of Kaunas University of Medicine, during the period from 2000 to 2005. Analysis of bipolar disorder course showed that five patients previously had been diagnosed with an episode of depression. The most frequent symptoms typical to bipolar disorder were disobedience and impulsive behavior, rapid changes of mood. The most common premorbid features were frequent changes of mood, being active in communication, hyperactive behavior. Adolescence-onset bipolar disorder was frequently comorbid with emotionally instable personality disorder, borderline type. Findings of the study confirm the notion that oppositional or impulsive behavior, rapid changes of mood without any reason, dysphoric mood and euphoric mood episodes with increased energy were cardinal symptoms of bipolar disorder with mania in adolescents. Most frequent premorbid features of these patients were quite similar to attention-deficit/hyperactivity disorder making differential diagnosis problematic.

  20. Radiofrequency-induced thermal therapy: results of a European multicentre study of resistive ablation of incompetent truncal varicose veins.

    Science.gov (United States)

    Braithwaite, B; Hnatek, L; Zierau, U; Camci, M; Akkersdijk, Gjm; Nio, D; Sarlija, M; Ajduk, M; Santoro, P; Roche, E

    2013-02-01

    To investigate the effectiveness of bipolar radiofrequency-induced thermal therapy (RFITT) in a multicentre non-randomized study. Some 672 incompetent saphenous veins (85% great saphenous varicose vein, 15% short saphenous vein) in 462 patients (56.5% CEAP [clinical, aetiological, anatomical and pathological elements] class 3 or worse) were treated in eight European centres. Patients were assessed between 180 and 360 days postoperatively. Occlusion rates were determined by duplex ultrasound and compared with the power used for treatment, pull back rate and experience of the operating surgeon. Complete occlusion rates of 98.4% were achieved when treatments were performed by an experienced operator (more than 20 cases), when the maximum power setting on the RFITT generator was between 18 and 20 W and the applicator was withdrawn at a rate slower than 1.5 second/cm RFITT is efficacious, well tolerated by patients and has a low incidence of procedure-related post-operative complications.

  1. Effect of radiofrequency on capacitance of low density plasma sheath

    International Nuclear Information System (INIS)

    Carneiro, L.T.; Cunha Rapozo, C. da

    1988-01-01

    It is shown that the influence of induced radiofrequency potential (V RF ) modifies the Bohm theory on ion saturation current, measured with Langmuir probes. The effect of radiofrequency potential on diode type plasma sheath resonance is also investigated. (M.C.K.)

  2. CT-guided radiofrequency tumor ablation in children

    International Nuclear Information System (INIS)

    Botsa, Evanthia; Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas; Koutsogiannis, Ioannis; Ziakas, Panayiotis D.; Alexopoulou, Efthimia

    2014-01-01

    Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

  3. Level of Radiofrequency (RF) Radiations from GSM Base Stations ...

    African Journals Online (AJOL)

    Levels of radiofrequency radiations around two global systems for mobile communication (GSM) base stations located in the vicinity of a residential quarter and workplace complex were measured. The effects of the radiofrequency radiations on albino mice placed in exposure cages and located around the base stations ...

  4. Mechanisms for enlarging lesion size during irrigated tip radiofrequency ablation

    DEFF Research Database (Denmark)

    Petersen, Helen Høgh; Roman-Gonzalez, Javier; Johnson, Susan B

    2004-01-01

    INTRODUCTION: Irrigated tip radiofrequency ablation of cardiac arrhythmias was developed to increase the size of the radiofrequency-induced lesion, since cooling of the electrode tip allows use of higher power settings. The purpose of this study was to determine if the increased lesion size during...

  5. Occupational exposure to radiofrequency fields in antenna towers

    International Nuclear Information System (INIS)

    Alanko, T.; Hietanen, M.

    2007-01-01

    Exposure of workers to radiofrequency fields was assessed in two medium-sized antenna towers. Towers had transmitting antennas from different networks, e.g. mobile phone networks, radio and digital TV sub-stations and amateur radio. The levels of radiofrequency fields were measured close to the ladders of the towers. All measured values were below ICNIRP occupational reference levels. (authors)

  6. CT-guided radiofrequency tumor ablation in children

    Energy Technology Data Exchange (ETDEWEB)

    Botsa, Evanthia [National and Kapodistrian University of Athens, First Pediatric Clinic, Agia Sofia Children' s Hospital, Athens (Greece); Poulou, Loukia S.; Koundouraki, Antonia; Thanos, Loukas [Sotiria General Hospital for Chest Diseases, Department of Medical Imaging and Interventional Radiology, Athens (Greece); Koutsogiannis, Ioannis [General Military Hospital NIMTS, Department of Medical Imaging, Athens (Greece); Ziakas, Panayiotis D. [Warren Alpert Medical School of Brown University Rhode Island Hospital, Division of Infectious Diseases, Providence, RI (United States); Alexopoulou, Efthimia [Attikon University Hospital, Second Department of Radiology, Athens University School of Medicine, Athens (Greece)

    2014-11-15

    Image-guided radiofrequency ablation is a well-accepted technique of interventional oncology in adults. To evaluate the efficacy and safety of CT-guided radiofrequency ablation as a minimally invasive treatment for metastatic neoplasms in children. A total of 15 radiofrequency ablation sessions were performed in 12 children and young adults (median age 9.5; range 5-18 years) with metastatic malignancies. Seven children and young adults had secondary hepatic lesions, three had pulmonary and two had bone lesions. Radiofrequency ablation was performed under conscious sedation. The median lesion size was 1.7 cm (range 1.3-2.8 cm). The median time for ablation was 8 min (range 7-10 min). Radiofrequency procedures were technically successful in all tumors. Postablation imaging immediately after, and 1 month and 3 months after radiofrequency ablation showed total necrosis in all patients. At 6-month follow-up, three patients (all with lesion size >2 cm) had local recurrence and underwent a second radiofrequency ablation session. At 2-year follow-up no patient had recurrence of the treated tumor. Post-ablation syndrome occurred in four children. No major complication occurred. CT-guided radiofrequency tumor ablation was safe and efficient for palliative treatment in our cohort of patients. (orig.)

  7. Paired structures and bipolar knowledge representation

    DEFF Research Database (Denmark)

    Montero, Javier; Bustince, Humberto; Franco, Camilo

    In this strictly positional paper we propose a general approach to bipolar knowledge representation, where the meaning of concepts can be modelled by examining their decomposition into opposite and neutral categories. In particular, it is the semantic relationship between the opposite categories...... and at the same time the type of neutrality rising in between opposites. Based on this first level of bipolar knowledge representation, paired structures in fact offer the means to characterize a specific bipolar valuation scale depending on the meaning of the concept that has to be verified. In this sense...

  8. Bipolar Disorder and Early Affective Trauma.

    Science.gov (United States)

    de Codt, Aloise; Monhonval, Pauline; Bongaerts, Xavier; Belkacemi, Ikram; Tecco, Juan Martin

    2016-09-01

    Bipolar disorder is a chronic psychiatric disease with a high prevalence and is a major psychosocial and medical burden. The exact etiological pathways of bipolar disorder are not fully understood. Genetic factors are known to play an important role in the etiology of bipolar disorder. However, high rates of discordance among identical twins and a growing body of evidence that environmental factors such as early stress can influence the onset and course of psychiatric diseases underline the importance of additional etiological mechanisms of bipolar disorders. There has been little investigation about early trauma in bipolar disorder. The aim of this study was to review the literature on the association between early traumatic interactions like child neglect, mistreatment, abuse or early parental separation and the occurrence of bipolar disorder in adulthood or impact on the course of the disease. Studies investigating associations between child neglect, mistreatment, abuse or early parental separation and occurrence of bipolar disorder in adulthood or impact on the course of the disease were searched in the Pubmed database. More than 700 articles were sorted independently by two of the authors using predefined criteria. Only research articles, reviews and meta-analyses were selected for this review. 53 articles met the inclusion criteria. To date, four systematic reviews partially addressed our research question. Early trauma is more frequently found in the past of bipolar patients than in the general population. Studies support a harmful effect of childhood trauma on the course of bipolar disease, with more anxious, depressive or psychotic symptoms, an early age of onset and a worse prognosis. Early trauma is more often found in the past of bipolar adult patients than the general population and studies support a harmful effect of childhood trauma on the course of bipolar disease, with more anxious, depressive or psychotic symptoms, an early age of onset and a

  9. Ionizing radiations simulation on bipolar components

    International Nuclear Information System (INIS)

    Montagner, X.

    1999-01-01

    This thesis presents the ionizing radiation effects on bipolar components and more specially their behavior facing the total dose. The first part is devoted to the radiation environments with a special attention to the spatial environments and new emergent environments. The specificities of bipolar components are then presented and their behavior facing the interactions. The physical mechanisms bound to the dose rate are also discussed. The second part presents a physical analysis of degradations induced by the cumulated dosimetry on bipolar components and simulation with the ATLAS code. The third part exposes an electric empirical simulation induced by the cumulated dose in static conditions. (A.L.B.)

  10. Progression along the Bipolar Spectrum: A Longitudinal Study of Predictors of Conversion from Bipolar Spectrum Conditions to Bipolar I and II Disorders

    Science.gov (United States)

    Alloy, Lauren B.; Urošević, Snežana; Abramson, Lyn Y.; Jager-Hyman, Shari; Nusslock, Robin; Whitehouse, Wayne G.; Hogan, Michael

    2011-01-01

    Little longitudinal research has examined progression to more severe bipolar disorders in individuals with “soft” bipolar spectrum conditions. We examine rates and predictors of progression to bipolar I and II diagnoses in a non-patient sample of college-age participants (n = 201) with high General Behavior Inventory scores and childhood or adolescent onset of “soft” bipolar spectrum disorders followed longitudinally for 4.5 years from the Longitudinal Investigation of Bipolar Spectrum (LIBS) project. Of 57 individuals with initial cyclothymia or bipolar disorder not otherwise specified (BiNOS) diagnoses, 42.1% progressed to a bipolar II diagnosis and 10.5% progressed to a bipolar I diagnosis. Of 144 individuals with initial bipolar II diagnoses, 17.4% progressed to a bipolar I diagnosis. Consistent with hypotheses derived from the clinical literature and the Behavioral Approach System (BAS) model of bipolar disorder, and controlling for relevant variables (length of follow-up, initial depressive and hypomanic symptoms, treatment-seeking, and family history), high BAS sensitivity (especially BAS Fun Seeking) predicted a greater likelihood of progression to bipolar II disorder, whereas early age of onset and high impulsivity predicted a greater likelihood of progression to bipolar I (high BAS sensitivity and Fun-Seeking also predicted progression to bipolar I when family history was not controlled). The interaction of high BAS and high Behavioral Inhibition System (BIS) sensitivities also predicted greater likelihood of progression to bipolar I. We discuss implications of the findings for the bipolar spectrum concept, the BAS model of bipolar disorder, and early intervention efforts. PMID:21668080

  11. The thermodynamics of bipolarity: a bifurcation model of bipolar illness and bipolar character and its psychotherapeutic applications.

    Science.gov (United States)

    Sabelli, H C; Carlson-Sabelli, L; Javaid, J I

    1990-11-01

    Two models dominate current formulations of bipolar illness: the homeostatic model implicit in Freud's psychodynamics and most neuroamine deficit/excess theories; and the oscillatory model of exaggerated biological rhythms. The homeostatic model is based on the closed systems approach of classic thermodynamics, while the oscillatory model requires the open systems approach of modern thermodynamics. Here we present a thermodynamic model of bipolarity that includes both homeostatic and oscillatory features and adds the most important feature of open systems thermodynamics: the creation of novel structures in bifurcation processes. According to the proposed model, bipolarity is the result of exaggerated biological energy that augments homeostatic, oscillatory and creative psychological processes. Only low-energy closed systems tend to rest ("point attractor") and entropic disorder. Open processes containing and exchanging energy fluctuate between opposite states ("periodic attractors"); they are characteristic of most physiological rhythms and are exaggerated in bipolar subjects. At higher energies, their strong fluctuations destroy pre-existing patterns and structures, produce turbulence ("chaotic attractors"), which sudden switches between opposite states, and create new and more complex structures. Likewise, high-energy bipolars develop high spontaneity, great fluctuations between opposite moods, internal and interpersonal chaos, and enhanced creativity (personal, artistic, professional) as well as psychopathology (personality deviations, psychotic delusions). Offered here is a theoretical explanation of the dual--creative and destructive--nature of bipolarity in terms of the new enantiodromic concept of entropy generalized by process theory. Clinically, this article offers an integrative model of bipolarity that accounts for many clinical features and contributes to a definition of the bipolar personality.

  12. [Application of radiofrequency vaporization in arthroscopic treatment of patellofemoral joint disorders].

    Science.gov (United States)

    Xuan, Tao; Xu, Bin; Xu, Honggang; Wang, Hao

    2009-01-01

    To explore the treatment of patellofemoral joint disorders with radiofrequency vaporization under arthroscopy. From June 2004 to June 2007, 86 cases of patellofemoral joint disorder (98 knees) were treated by lateral retinacular release or medial retinacular tighten added, and combined with bipolar radiofrequency chondroplasty under arthroscopy. There were 30 males (34 knees) and 56 females (64 knees), aging 15-68 years (mean 40 years). The locations were left in 42 cases, right in 32 cases, both sides in 12 cases. The disease course was 3 months to 6 years (mean 30.5 months). In 98 knees, there were 28 knees of static patellar tilt, 10 knees of static patellar subluxation, 45 knees of dynamic patellar tilt and 15 knees of dynamic patellar subluxation. The Lysholm knee score preoperatively was 57.72 +/- 8.86. The patellofemoral cartilage abnormality were classified according to the Outerbridge grade (18 knees of grade I, 36 knees of grade II, 32 knees of grade III and 12 knees of grade IV). The incisions healed by first intention without complications such as infection or hemarthrosis. Seventy-five cases (82 knees) were followed up 8-37 months (mean 20.6 months). One month after operation, the patellofemoral joint pain was relieved remarkably, the knee joint activity was good and the radiological outcomes was also satisfactory. Six months after operation, the Lysholm knee score was improved significantly in patients of grades I, II and III (P 0.05). The postoperative score was 69.95 +/- 5.42 (P joint disorders.

  13. Analysis of public perception of increased radiofrequency exposure from mobile phone in Southwestern Nigeria

    International Nuclear Information System (INIS)

    Oladapo, O.O.; Ishola, G.A.; Ayokunnnu, D.O.

    2011-01-01

    Wireless communication devices have been increasingly used recently in Nigeria with a corresponding public perception of increase in radiofrequency (RF) radiation. This perception has developed into public concerns, thus requiring verification. For the purpose of verification, a survey in form of an opinion poll was conducted by means of an interview using questionnaires. The survey shows that people actually experienced symptoms like headache, fatigue, dizziness, and heat sensation. However, out of the respondents that have experienced one symptoms or the other, 84% still believe it is safe to use mobile phones. Only 4 % of those that claimed they experienced symptoms had consulted a doctor in connection with the symptoms.

  14. Physical mechanisms contributing to enhanced bipolar gain degradation at low dose rates

    International Nuclear Information System (INIS)

    Fleetwood, D.M.; Reber, R.A. Jr.; Winokur, P.S.; Kosier, S.L.; Schrimpf, R.D.; Wei, A.; DeLaus, M.; Combs, W.E.; Pease, R.L.

    1994-01-01

    The authors have performed capacitance-voltage (C-V) and thermally-stimulated-current (TSC) measurements on non-radiation-hard MOS capacitors simulating screen oxides of modern bipolar technologies. For 0-V irradiation of ∼25 C, the net trapped-positive-charge density (N ox ) inferred from midgap C-V shifts is ∼25--40% greater for low-dose-rate ( 2 )/s) than for high-dose-rate (> 100 rad(SiO 2 )/s) exposure. Device modeling shows that such a difference in screen-oxide N ox is enough to account for the enhanced low-rate gain degradation often observed in bipolar devices, due to the ∼ exp(N ox 2 ) dependence of the excess base current. At the higher rates, TSC measurements reveal a ∼10% decrease in trapped-hole density over low rates. Also, at high rates, up to ∼2.5-times as many trapped holes are compensated by electrons in border traps than at low rates for these devices and irradiation conditions. Both the reduction in trapped-hole density and increased charge compensation reduce the high-rate midgap shift. A physical model is developed which suggests that both effects are caused by time-dependent space charge in the bulk of these soft oxides associated with slowly transporting and/or metastably trapped holes (e.g., in Eδ' centers). On the basis of this model, bipolar transistors and screen-oxide capacitors were irradiated at 60 C at 200 rad(SiO 2 )/s in a successful effort to match low-rate damage. these surprising results provide insight into enhanced low-rate bipolar gain degradation and suggest potentially promising new approaches to bipolar and BiCMOS hardness assurance for space applications

  15. Active stabilization of ion trap radiofrequency potentials

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, K. G.; Wong-Campos, J. D.; Restelli, A.; Landsman, K. A.; Neyenhuis, B.; Mizrahi, J.; Monroe, C. [Joint Quantum Institute and University of Maryland Department of Physics, College Park, Maryland 20742 (United States)

    2016-05-15

    We actively stabilize the harmonic oscillation frequency of a laser-cooled atomic ion confined in a radiofrequency (rf) Paul trap by sampling and rectifying the high voltage rf applied to the trap electrodes. We are able to stabilize the 1 MHz atomic oscillation frequency to be better than 10 Hz or 10 ppm. This represents a suppression of ambient noise on the rf circuit by 34 dB. This technique could impact the sensitivity of ion trap mass spectrometry and the fidelity of quantum operations in ion trap quantum information applications.

  16. Ion transmission in a linear radiofrequency spectrometer

    International Nuclear Information System (INIS)

    Gomet, J.-C.

    1975-01-01

    A linear radiofrequency spectrometer is used for the purpose of experimental determination of the absolute ionization cross sections of various ions obtained by electron impact on polyatomic molecules. The transmission of the apparatus is studied: it does not only depend on the mass resolution of the spectrometer, but also on the nature of ions. It is affected by charge transfers, especially for the parent ions. An empiric way of correction of the apparatus function is given which allows the use at 10 -6 Torr [fr

  17. Radiofrequency Energy and Electrode Proximity Influences Stereoelectroencephalography-Guided Radiofrequency Thermocoagulation Lesion Size: An In Vitro Study with Clinical Correlation.

    Science.gov (United States)

    Staudt, Michael D; Maturu, Sarita; Miller, Jonathan P

    2018-02-16

    Radiofrequency thermocoagulation of epileptogenic foci via stereoelectroencephalography (SEEG) electrodes has been suggested as a treatment for medically intractable epilepsy, but reported outcomes have been suboptimal, possibly because lesions generated using conventional high-energy radiofrequency parameters are relatively small. To describe a technique of delivering low energy across separate SEEG electrodes in order to create large confluent radiofrequency lesions. The size and configuration of radiofrequency lesions using different radiofrequency intensity and interelectrode distance was assessed in egg whites. Magnetic resonance images (MRI) from 3 patients who had undergone radiofrequency lesion creation were evaluated to determine the contribution of lesion intensity and electrode separation on lesion size. Electroencephalography, MRI, and clinical data were assessed before and after lesion creation. Both in Vitro and in Vivo analysis revealed that less energy paradoxically produced larger lesions, with the largest possible lesions produced when radiofrequency power was applied for long duration at less than 3 W. Linear separation of electrodes also contributed to lesion size, with largest lesions produced when electrodes were separated by a linear distance of between 5 and 12 mm. Clinical lesions produced using these parameters were large and resulted in improvement in interictal and ictal activity. Radiofrequency lesions produced using low-energy delivery between SEEG electrodes in close proximity can produce a large lesion. These findings might have advantages for treatment of focal epilepsy.

  18. Fabrication of a Silicon MOSFET Device with Bipolar Transistor Source,

    Science.gov (United States)

    1980-07-01

    NEGATIVE PHOTORESIST PROCEDURE ’•J n •:• fi >. 3 u i fc- Process Coat wafer Air dry Pre bake the resist coating Expose Develop Method Time...Orange (rather broad for orange) 0.82 Salmon 0.85 Dull, light red-violet 0.86 Violet £ 0.87 Blue-violet 0.89 Blue ::’ 0.92 V Blue-green •I 0.95

  19. Oxadiazole-Based Highly Efficient Bipolar Fluorescent Emitters for Organic Light-Emitting Diodes

    Directory of Open Access Journals (Sweden)

    Qiong Wu

    2018-04-01

    Full Text Available In this study, a series of bipolar fluorescence emitters named 2DPAc-OXD, DPAc-OXD, 2PTZ-OXD and PTZ-OXD were designed and synthesized with excellent yields. The characterization of materials was investigated by using nuclear magnetic resonance (NMR (1H, 13C, mass spectrometry and thermogravimetric analysis (TGA. To investigate device efficiencies, two different OLED devices (Device 1, Device 2 were fabricated with two different host materials (Bepp2, DPEPO. The Device 2 with 2PTZ-OXD as fluorescent emitter exhibited excellent power and current efficiencies of 6.88 Lm/W and 10.10 cd/A, respectively. The external quantum efficiency of 2PTZ-OXD was around 3.99% for Device 2. The overall device properties of phenothiazine donor were better than acridine derivatives.

  20. Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

    Energy Technology Data Exchange (ETDEWEB)

    Park, Seung Hee; Yun, Chung Bang [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Inman, Daniel J. [Virginia Polytechnic Institute and State University, Virginia (United States)

    2007-06-15

    This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

  1. Remote Impedance-based Loose Bolt Inspection Using a Radio-Frequency Active Sensing Node

    International Nuclear Information System (INIS)

    Park, Seung Hee; Yun, Chung Bang; Inman, Daniel J.

    2007-01-01

    This paper introduces an active sensing node using radio-frequency (RF) telemetry. This device has brought the traditional impedance-based structural health monitoring (SHM) technique to a new paradigm. The RF active sensing node consists of a miniaturized impedance measuring device (AD5933), a microcontroller (ATmega128L), and a radio frequency (RF) transmitter (XBee). A macro-fiber composite (MFC) patch interrogates a host structure by using a self-sensing technique of the miniaturized impedance measuring device. All the process including structural interrogation, data acquisition, signal processing, and damage diagnostic is being performed at the sensor location by the microcontroller. The RF transmitter is used to communicate the current status of the host structure. The feasibility of the proposed SHM strategy is verified through an experimental study inspecting loose bolts in a bolt-jointed aluminum structure

  2. Climatic factors and bipolar affective disorder

    DEFF Research Database (Denmark)

    Christensen, Ellen Margrethe; Larsen, Jens Knud; Gjerris, Annette

    2008-01-01

    In bipolar disorder, the factors provoking a new episode are unknown. As a seasonal variation has been noticed, it has been suggested that weather conditions may play a role. The aim of the study was to elucidate whether meteorological parameters influence the development of new bipolar phases....... A group of patients with at least three previous hospitalizations for bipolar disorder was examined every 3 months for up to 3 years. At each examination an evaluation of the affective phase was made according to the Hamilton Depression Scale (HAM-D(17)), and the Bech-Rafaelsen Mania Rating Scale (MAS......). In the same period, daily recordings from the Danish Meteorological Institute were received. We found no correlations between onset of bipolar episodes [defined as MAS score of 11 or more (mania) and as HAM-D(17) score of 12 or more (depression)] and any meteorological parameters. We found a statistical...

  3. Bipolar or unipolar? : A brain teasing question

    NARCIS (Netherlands)

    Rive, M.M.

    2017-01-01

    During the depressed or remitted states, major depressive disorder (MDD) and bipolar disorder (BD) are difficult to distinguish clinically. Treatments for both disorders differ, and inadequate treatment may lead to chronicity, poor psychosocial functioning, or even suicide. Although early

  4. Internet use by patients with bipolar disorder

    DEFF Research Database (Denmark)

    Bauer, Rita; Conell, Jörn; Glenn, Tasha

    2016-01-01

    There is considerable international interest in online education of patients with bipolar disorder, yet little understanding of how patients use the Internet and other sources to seek information. 1171 patients with a diagnosis of bipolar disorder in 17 countries completed a paper-based, anonymous...... survey. 81% of the patients used the Internet, a percentage similar to the general public. Older age, less education, and challenges in country telecommunications infrastructure and demographics decreased the odds of using the Internet. About 78% of the Internet users looked online for information...... on bipolar disorder or 63% of the total sample. More years of education in relation to the country mean, and feeling very confident about managing life decreased the odds of seeking information on bipolar disorder online, while having attended support groups increased the odds. Patients who looked online...

  5. Are rates of pediatric bipolar disorder increasing?

    DEFF Research Database (Denmark)

    Kessing, Lars Vedel; Vradi, Eleni; Andersen, Per Kragh

    2014-01-01

    Studies from the USA suggest that rates of pediatric bipolar disorder have increased since the mid-90s, but no study outside the USA has been published on the rates of pediatric bipolar disorder. Further, it is unclear whether an increase in rates reflects a true increase in the illness or more...... diagnostic attention. Using nationwide registers of all inpatients and outpatients contacts to all psychiatric hospitals in Denmark, we investigated (1) gender-specific rates of incident pediatric mania/bipolar disorder during a period from 1995 to 2012, (2) whether age and other characteristics...... for pediatric mania/bipolar disorder changed during the calendar period (1995 to 2003 versus 2004 to 2012), and (3) whether the diagnosis is more often made at first psychiatric contact in recent time compared to earlier according to gender. Totally, 346 patients got a main diagnosis of a manic episode (F30...

  6. Biological dysrhythm in remitted bipolar I disorder.

    Science.gov (United States)

    Iyer, Aishwarya; Palaniappan, Pradeep

    2017-12-01

    Recent treatment guidelines support treatment of biological rhythm abnormalities as a part of treatment of bipolar disorder, but still, literature examining various domains (Sleep, Activity, Social, and Eating) of biological rhythm and its clinical predictors are less. The main aim of our study is to compare various domains of biological rhythm among remitted bipolar I subjects and healthy controls. We also explored for any association between clinical variables and biological rhythm among bipolar subjects. 40 subjects with Bipolar I disorder and 40 healthy controls who met inclusion and exclusion criteria were recruited for the study. Diagnoses were ascertained by a qualified psychiatrist using MINI 5.0. Sociodemographic details, biological rhythm (BRIAN-Biological Rhythm Interview of assessment in Neuropsychiatry) and Sleep functioning (PSQI- Pittsburgh Sleep Quality Index) were assessed in all subjects. Mean age of the Bipolar subjects and controls were 41.25±11.84years and 38.25±11.25 years respectively. Bipolar subjects experienced more biological rhythm disturbance when compared to healthy controls (total BRIAN score being 34.25±9.36 vs 28.2±6.53) (p=0.002). Subsyndromal depressive symptoms (HDRS) had significant positive correlation with BRIAN global scores(r=0.368, p=0.02). Linear regression analysis showed that number of episodes which required hospitalization (β=0.601, t=3.106, P=0.004), PSQI (β=0.394, t=2.609, p=0.014), HDRS (β=0.376, t=2.34, t=0.036) explained 31% of variance in BRIAN scores in remitted bipolar subjects. Biological rhythm disturbances seem to persist even after clinical remission of bipolar illness. More studies to look into the impact of subsyndromal depressive symptoms on biological rhythm are needed. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Suicide in bipolar disorder: a review.

    Science.gov (United States)

    Latalova, Klara; Kamaradova, Dana; Prasko, Jan

    2014-06-01

    Suicide is a leading cause of death in patients with bipolar disorder. Risk factors and prevention of suicide in this illness are the focus of considerable current research. MEDLINE data base was searched for the key words "bipolar disorder" with "suicide", "lithium" with "suicide", "anticonvulsants" with "bipolar disorder", and "anticonvulsants" with "bipolar disorder" and with "suicide". No language or time constraints were applied. The lists of references were searched manually to find additional articles. It is estimated that 25% to 50% of patients with bipolar disorder will attempt suicide at least once over their lifetime, and that 8% to 19% will complete suicide. Mortality rates from cardiovascular diseases are elevated in bipolar disorder. Risk factors for suicide include younger age of onset of the illness, history of past suicidal behavior, family history of suicide acts, comorbid borderline personality disorder and substance use disorders, and hopelessness. The warning signs calling for immediate action include the patients threatening to harm themselves, or looking for ways to kill themselves (seeking access to pills or weapons), or the patient talking or writing about death. Robust evidence supports the effects of lithium treatment in reducing suicidal attempts and completions in bipolar disorder. The evidence for antisuicidal effects of anticonvulsants is weaker. Nevertheless, valproate and other anticonvulsants are frequently prescribed as mood stabilizers. There have been controversial suggestions that this treatment may elevate the risk of suicide, but the data supporting this are not convincing. Psychoeducation can reduce the number of suicide attempts and completions. Suicide in bipolar disorder is a major public health problem. Recent research has expanded our knowledge of risk factors and warning signs. Nevertheless, it appears that the introduction of lithium treatment in the 1970s was the most recent important breakthrough in the prevention

  8. Evaluation of Enhanced Low Dose Rate Sensitivity in Discrete Bipolar Junction Transistors

    Science.gov (United States)

    Chen, Dakai; Ladbury Raymond; LaBel, Kenneth; Topper, Alyson; Ladbury, Raymond; Triggs, Brian; Kazmakites, Tony

    2012-01-01

    We evaluate the low dose rate sensitivity in several families of discrete bipolar transistors across device parameter, quality assurance level, and irradiation bias configuration. The 2N2222 showed the most significant low dose rate sensitivity, with low dose rate enhancement factor of 3.91 after 100 krad(Si). The 2N2907 also showed critical degradation levels. The devices irradiated at 10 mrad(Si)/s exceeded specifications after 40 and 50 krad(Si) for the 2N2222 and 2N2907 devices, respectively.

  9. Minimal vascular flows cause strong heat sink effects in hepatic radiofrequency ablation ex vivo.

    Science.gov (United States)

    Lehmann, Kai S; Poch, Franz G M; Rieder, Christian; Schenk, Andrea; Stroux, Andrea; Frericks, Bernd B; Gemeinhardt, Ole; Holmer, Christoph; Kreis, Martin E; Ritz, Jörg P; Zurbuchen, Urte

    2016-08-01

    The present paper aims to assess the lower threshold of vascular flow rate on the heat sink effect in bipolar radiofrequency ablation (RFA) ex vivo. Glass tubes (vessels) of 3.4 mm inner diameter were introduced in parallel to bipolar RFA applicators into porcine liver ex vivo. Vessels were perfused with flow rates of 0 to 1,500 ml/min. RFA (30 W power, 15 kJ energy input) was carried out at room temperature and 37°C. Heat sink effects were assessed in RFA cross sections by the decrease in ablation radius, area and by a high-resolution sector planimetry. Flow rates of 1 ml/min already caused a significant cooling effect (P ≤ 0.001). The heat sink effect reached a maximum at 10 ml/min (18.4 mm/s) and remained stable for flow rates up to 1,500 ml/min. Minimal vascular flows of ≥1 ml/min cause a significant heat sink effect in hepatic RFA ex vivo. A lower limit for volumetric flow rate was not found. The maximum of the heat sink effect was reached at a flow rate of 10 ml/min and remained stable for flow rates up to 1,500 ml/min. Hepatic inflow occlusion should be considered in RFA close to hepatic vessels. © 2016 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  10. Investigation of radiofrequency plasma sources for space travel

    International Nuclear Information System (INIS)

    Charles, C; Boswell, R W; Takahashi, K

    2012-01-01

    Optimization of radiofrequency (RF) plasma sources for the development of space thrusters differs from other applications such as plasma processing of materials since power efficiency, propellant usage, particle acceleration or heating become driving parameters. The development of two RF (13.56 MHz) plasma sources, the high-pressure (∼1 Torr) capacitively coupled ‘pocket rocket’ plasma micro-thruster and the low-pressure (∼1 mTorr) inductively coupled helicon double layer thruster (HDLT), is discussed within the context of mature and emerging electric propulsion devices. The density gradient in low-pressure expanding RF plasmas creates an electric field that accelerates positive ions out of the plasma. Generally, the total potential drop is similar to that of a wall sheath allowing the plasma electrons to neutralize the ion beam. A high-pressure expansion with no applied magnetic field can result in large dissociation rates and/or a collimated beam of ions of small area and a flowing heated neutral beam (‘pocket rocket’). A low-pressure expansion dominated by a magnetic field can result in the formation of electric double layers which produce a very directed neutralized beam of ions of large area (HDLT). (paper)

  11. Investigation of radiofrequency plasma sources for space travel

    Science.gov (United States)

    Charles, C.; Boswell, R. W.; Takahashi, K.

    2012-12-01

    Optimization of radiofrequency (RF) plasma sources for the development of space thrusters differs from other applications such as plasma processing of materials since power efficiency, propellant usage, particle acceleration or heating become driving parameters. The development of two RF (13.56 MHz) plasma sources, the high-pressure (˜1 Torr) capacitively coupled ‘pocket rocket’ plasma micro-thruster and the low-pressure (˜1 mTorr) inductively coupled helicon double layer thruster (HDLT), is discussed within the context of mature and emerging electric propulsion devices. The density gradient in low-pressure expanding RF plasmas creates an electric field that accelerates positive ions out of the plasma. Generally, the total potential drop is similar to that of a wall sheath allowing the plasma electrons to neutralize the ion beam. A high-pressure expansion with no applied magnetic field can result in large dissociation rates and/or a collimated beam of ions of small area and a flowing heated neutral beam (‘pocket rocket’). A low-pressure expansion dominated by a magnetic field can result in the formation of electric double layers which produce a very directed neutralized beam of ions of large area (HDLT).

  12. Actual role of radiofrequency ablation of liver metastases

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Philippe L. [Eberhard-Karls-University of Tuebingen, Department of Diagnostic Radiology, Tuebingen (Germany)

    2007-08-15

    The liver is, second only to lymph nodes, the most common site for metastatic disease irrespective of the primary tumour. More than 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improved survival in patients with colorectal metastases, only approximately 20% of patients are eligible for surgery. Thermal ablation and especially radiofrequency ablation emerge as an important additional therapy modality for the treatment of liver metastases. RF ablation shows a benefit in life expectancy and may lead in a selected patient group to cure. Percutaneous RF ablation appears safer (versus cryotherapy), easier (versus laser), and more effective (versus ethanol instillation and transarterial chemoembolisation) compared with other minimally invasive procedures. RF ablation can be performed by a percutaneous, laparoscopical or laparotomic approach, and may be potentially combined with chemotherapy and surgery. At present ideal candidates have tumours with a maximum diameter less than 3.5 cm. An untreatable primary tumour or a systemic disease represents contraindications for performing local therapies. Permanent technical improvements of thermal ablation devices and a better integration of thermal ablation in the overall patient care may lead to prognosis improvement in patients with liver metastases. (orig.)

  13. Actual role of radiofrequency ablation of liver metastases

    International Nuclear Information System (INIS)

    Pereira, Philippe L.

    2007-01-01

    The liver is, second only to lymph nodes, the most common site for metastatic disease irrespective of the primary tumour. More than 50% of all patients with malignant diseases will develop liver metastases with a significant morbidity and mortality. Although the surgical resection leads to an improved survival in patients with colorectal metastases, only approximately 20% of patients are eligible for surgery. Thermal ablation and especially radiofrequency ablation emerge as an important additional therapy modality for the treatment of liver metastases. RF ablation shows a benefit in life expectancy and may lead in a selected patient group to cure. Percutaneous RF ablation appears safer (versus cryotherapy), easier (versus laser), and more effective (versus ethanol instillation and transarterial chemoembolisation) compared with other minimally invasive procedures. RF ablation can be performed by a percutaneous, laparoscopical or laparotomic approach, and may be potentially combined with chemotherapy and surgery. At present ideal candidates have tumours with a maximum diameter less than 3.5 cm. An untreatable primary tumour or a systemic disease represents contraindications for performing local therapies. Permanent technical improvements of thermal ablation devices and a better integration of thermal ablation in the overall patient care may lead to prognosis improvement in patients with liver metastases. (orig.)

  14. Cell oxidation-reduction imbalance after modulated radiofrequency radiation.

    Science.gov (United States)

    Marjanovic, Ana Marija; Pavicic, Ivan; Trosic, Ivancica

    2015-01-01

    Aim of this study was to evaluate an influence of modulated radiofrequency field (RF) of 1800 MHz, strength of 30 V/m on oxidation-reduction processes within the cell. The assigned RF field was generated within Gigahertz Transversal Electromagnetic Mode cell equipped by signal generator, modulator, and amplifier. Cell line V79, was irradiated for 10, 30, and 60 min, specific absorption rate was calculated to be 1.6 W/kg. Cell metabolic activity and viability was determined by MTT assay. In order to define total protein content, colorimetric method was used. Concentration of oxidised proteins was evaluated by enzyme-linked immunosorbent assay. Reactive oxygen species (ROS) marked with fluorescent probe 2',7'-dichlorofluorescin diacetate were measured by means of plate reader device. In comparison with control cell samples, metabolic activity and total protein content in exposed cells did not differ significantly. Concentrations of carbonyl derivates, a product of protein oxidation, insignificantly but continuously increase with duration of exposure. In exposed samples, ROS level significantly (p < 0.05) increased after 10 min of exposure. Decrease in ROS level was observed after 30-min treatment indicating antioxidant defence mechanism activation. In conclusion, under the given laboratory conditions, modulated RF radiation might cause impairment in cell oxidation-reduction equilibrium within the growing cells.

  15. RADIOFREQUENCY AND MICROWAVE RADIATION HEALTH EFFECTS AND OCCUPATIONAL EXPOSURE

    Directory of Open Access Journals (Sweden)

    Ivana Damnjanović

    2011-12-01

    Full Text Available In the recent years, there have been considerable discussion and concern about the possible hazards of RF/MW radiation. More recently, the growth and development in personal mobile communications have focused attention on the frequencies associated with this technology. A number of studies have examined the health effects of RF/MW electromagnetic fields (EMFs, originating from occupational exposure, hobbies, or residence near the radio or television transmitters. Particularly controversial are the biophysical mechanisms by which these RF fields may affect biological systems. General health effects reviews explore possible carcinogenic, reproductive and neurological effects. Health effects by exposure source have been observed in radar traffic devices, wireless communications with cellular phones, radio transmission, and magnetic resonance imaging (MRI. Several epidemiological surveys have suggested associations with non-specific complaints such as headache, tiredness, sleep disturbance, loss of memory, and dizziness. These findings, which echo reports of illness associated with other types of radiofrequency (RF radiation, relate not only to the use of mobile phones, but also to residence near the mobile phone base stations and other settings involving occupational exposure. The biological effects suggest that some precautions are necessary, and preventive approaches are highly recommended. Further researches are required to give more information about the effects of microwave radiation on our health, especially in occupational setting and professionally exposed workers.

  16. Preparation of bipolar membranes by electrospinning

    International Nuclear Information System (INIS)

    Pan, Jiefeng; Hou, Linxiao; Wang, Qiuyue; He, Yubin; Wu, Liang; Mondal, Abhishek N.; Xu, Tongwen

    2017-01-01

    A new preparative pathway for the bipolar membranes was initiated via the electrospinning and hot-press process. The prepared bipolar membrane was consisting of sulfonated poly (phenylene oxide), polyethylene glycol, and quaternized poly (phenylene oxide). The above mentioned membrane was fabricated by the continuous electrospinning of the respective layer, followed by the solvent atmosphere treatment and hot-pressing, to obtain a transparent and dense structure. The thickness of each layer can be easily tuned by controlling the electrospinning parameters. The clear interfacial structure was observed and confirmed by the scanning electron microscope. The bipolar performance is evaluated by the current–voltage curves and production yield of acid and base. The final optimized bipolar membrane had similar yield of acid and base as the casting membrane. However, extremely lower potential drop value was observed when they are applied for the production of acid and base. The experimental results showed that, electrospinning is an effective and well controlled way to fabricate bipolar membranes, in which anion or cation exchange layer as well as interfacial layer can be easily changed or added as requested. - Highlights: • Bipolar membranes were prepared through electrospinning followed by post-treatment. • As-prepared membranes were successfully applied in electrodialysis for production of acid and base. • Electrospun membranes exhibit better performance than the casting ones.

  17. Preparation of bipolar membranes by electrospinning

    Energy Technology Data Exchange (ETDEWEB)

    Pan, Jiefeng; Hou, Linxiao; Wang, Qiuyue; He, Yubin; Wu, Liang; Mondal, Abhishek N.; Xu, Tongwen, E-mail: twxu@ustc.edu.cn

    2017-01-15

    A new preparative pathway for the bipolar membranes was initiated via the electrospinning and hot-press process. The prepared bipolar membrane was consisting of sulfonated poly (phenylene oxide), polyethylene glycol, and quaternized poly (phenylene oxide). The above mentioned membrane was fabricated by the continuous electrospinning of the respective layer, followed by the solvent atmosphere treatment and hot-pressing, to obtain a transparent and dense structure. The thickness of each layer can be easily tuned by controlling the electrospinning parameters. The clear interfacial structure was observed and confirmed by the scanning electron microscope. The bipolar performance is evaluated by the current–voltage curves and production yield of acid and base. The final optimized bipolar membrane had similar yield of acid and base as the casting membrane. However, extremely lower potential drop value was observed when they are applied for the production of acid and base. The experimental results showed that, electrospinning is an effective and well controlled way to fabricate bipolar membranes, in which anion or cation exchange layer as well as interfacial layer can be easily changed or added as requested. - Highlights: • Bipolar membranes were prepared through electrospinning followed by post-treatment. • As-prepared membranes were successfully applied in electrodialysis for production of acid and base. • Electrospun membranes exhibit better performance than the casting ones.

  18. Comorbidity bipolar disorder and personality disorders.

    Science.gov (United States)

    Latalova, Klara; Prasko, Jan; Kamaradova, Dana; Sedlackova, Jana; Ociskova, Marie

    2013-01-01

    Outcome in bipolar patients can be affected by comorbidity of other psychiatric disorders. Comorbid personality disorders are frequent and may complicate the course of bipolar illness. We have much information about treating patients with uncomplicated bipolar disorder (BD) but much less knowledge about possibilities for patients with the comorbidity of BD and personality disorder. We conducted a series of literature searches using, as key words or as items in indexed fields, bipolar disorder and personality disorder or personality traits. Articles were obtained by searching MEDLINE from 1970 to 2012. In addition, we used other papers cited in articles from these searches, or cited in articles used in our own work. Tests of personality traits indicated that euthymic bipolar patients have higher scores on harm avoidance, reward dependence, and novelty seeking than controls. Elevation of novelty seeking in bipolar patients is associated with substance abuse comorbidity. Comorbidity with personality disorders in BD patients is associated with a more difficult course of illness (such as longer episodes, shorter time euthymic, and earlier age at onset) and an increase in comorbid substance abuse, suicidality and aggression. These problems are particularly pronounced in comorbidity with borderline personality disorder. Comorbidity with antisocial personality disorder elicits a similar spectrum of difficulties; some of the antisocial behavior exhibited by patients with this comorbidity is mediated by increased impulsivity.

  19. The role of sleep in bipolar disorder

    Directory of Open Access Journals (Sweden)

    Gold AK

    2016-06-01

    Full Text Available Alexandra K Gold,1 Louisa G Sylvia,1,2 1Department of Psychiatry, Massachusetts General Hospital, 2Harvard Medical School, Boston, MA, USA Abstract: Bipolar disorder is a serious mental illness characterized by alternating periods of elevated and depressed mood. Sleep disturbances in bipolar disorder are present during all stages of the condition and exert a negative impact on overall course, quality of life, and treatment outcomes. We examine the partnership between circadian system (process C functioning and sleep–wake homeostasis (process S on optimal sleep functioning and explore the role of disruptions in both systems on sleep disturbances in bipolar disorder. A convergence of evidence suggests that sleep problems in bipolar disorder result from dysregulation across both process C and process S systems. Biomarkers of depressive episodes include heightened fragmentation of rapid eye movement (REM sleep, reduced REM latency, increased REM density, and a greater percentage of awakenings, while biomarkers of manic episodes include reduced REM latency, greater percentage of stage I sleep, increased REM density, discontinuous sleep patterns, shortened total sleep time, and a greater time awake in bed. These findings highlight the importance of targeting novel treatments for sleep disturbance in bipolar disorder. Keywords: bipolar disorder, circadian rhythms, sleep–wake homeostasis

  20. Classification of cognitive performance in bipolar disorder.

    Science.gov (United States)

    Sparding, Timea; Silander, Katja; Pålsson, Erik; Östlind, Josefin; Ekman, Carl Johan; Sellgren, Carl M; Joas, Erik; Hansen, Stefan; Landén, Mikael

    2017-09-01

    To understand the etiology of cognitive impairment associated with bipolar disorder, we need to clarify potential heterogeneity in cognitive functioning. To this end, we used multivariate techniques to study if the correlation structure of cognitive abilities differs between persons with bipolar disorder and controls. Clinically stable patients with bipolar disorder (type I: n = 64; type II: n = 44) and healthy controls (n = 86) were assessed with a wide range of cognitive tests measuring executive function, speed, memory, and verbal skills. Data were analysed with multivariate techniques. A distinct subgroup (∼30%) could be identified that performed significantly poorer on tests concerning memory function. This cognitive phenotype subgroup did not differ from the majority of bipolar disorder patients with respect to other demographic or clinical characteristics. Whereas the majority of patients performed similar to controls, a subgroup of patients with bipolar disorder differed substantially from healthy controls in the correlation pattern of low-level cognitive abilities. This suggests that cognitive impairment is not a general trait in bipolar disorder but characteristic of a cognitive subgroup. This has important clinical implications for cognitive rehabilitation and remediation.

  1. Neurohumoral indicators of efficacy radiofrequency cardiac denervation

    Energy Technology Data Exchange (ETDEWEB)

    Evtushenko, A. V., E-mail: ave@cardio-tomsk.ru; Evtushenko, V. V. [National Research Tomsk State University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Saushkina, Yu. V.; Gusakova, A. M.; Suslova, T. E.; Dymbrylova, O. N.; Smyshlyaev, K. A.; Kurlov, I. O. [Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Lishmanov, Yu. B.; Anfinogenova, Ya. D. [National Research Tomsk Polytechnic University, Tomsk (Russian Federation); Federal State Budgetary Scientific Institution “Research Institute for Cardiology”, Tomsk (Russian Federation); Sergeevichev, D. S. [Academician E.N. Meshalkin State Research Institute of Circulation Pathology, Novosibirsk (Russian Federation); Bykov, A. N.; Syryamkin, V. I.; Kistenev, Yu. V. [National Research Tomsk State University, Tomsk (Russian Federation); Lotkov, A. I. [Institute of Strength Physics and Materials Science of the Siberian Branch of the RAS, Tomsk (Russian Federation); Pokushalov, E. A.

    2015-11-17

    In this study, we compared pre- and postoperative parameters of the cardiac sympathetic innervation. The aim of the study was to examine the approaches to evaluating the quality of radiofrequency (RF)-induced cardiac denervation by using non-invasive and laboratory methods. The study included 32 people with long-lasting persistent atrial fibrillation (AF). The patients were divided into 2 groups according to the objectives of the study: group 1 (main) - 21 patients with mitral valve diseases, which simultaneously with radiofrequency ablation (RFA) AF carried out on the effects of the paraganglionic nervous plexuses by C. Pappone (2004) and N. Doll (2008) schemes. The second group (control) contained 11 patients with heart diseases in sinus rhythm (the RF denervation not been performed). All patients, who underwent surgical treatment, were received examination of cardiac sympathetic tone by using {sup 123}I-MIBG. All of them made blood analysis from ascending aorta and coronary sinus to determine the level of norepinephrine and its metabolites before and after cardiac denervation. Data of radionuclide examination are correlating with laboratory data.

  2. Radiofrequency spark chambers and delay line resonators

    International Nuclear Information System (INIS)

    Sayag, Jacques

    1971-01-01

    According to a suggestion of A. Kastler, a spark chamber was excited by an undamped radiofrequency pulse and tracks about 1 mm wide obtained; the result was interpreted by computation of the coefficients of electronic amplification and partial ambipolar diffusion. This work led us to the construction of a new fast triggering undamped wave-train generator of very high tension (patent taken out by the C.E.A. under the no.: EN 7 134 650 the 27.9.1971). Since this apparatus uses a resonant storage line, its design implied a precise knowledge of high impedance delay lines. The experimental radiofrequency spectra of the input impedance of opened or short-circuited lines were plotted completely and analysed by the circuits theory, new measuring methods were established, dispersion relations accurately checked and the equivalence of the formulas, within the third order, with theses of Debye's Dipolar Absorption demonstrated. General properties of Hilbert's transform were also investigated. From the experimental point of view, the electromagnetic energy storage process was extended to the case of a liquid nitrogen-immersed resonant delay line. The good behavior of the cryogenic experiment, where the main difficulty of icing was overcame by the construction of special electrodes, offers great promise for extrapolation to superconductivity. (author) [fr

  3. A sheath model for arbitrary radiofrequency waveforms

    Science.gov (United States)

    Turner, M. M.; Chabert, Pascal

    2012-10-01

    The sheath is often the most important region of a rf plasma, because discharge impedance, power absorption and ion acceleration are critically affected by the behaviour of the sheath. Consequently, models of the sheath are central to any understanding of the physics of rf plasmas. Lieberman has supplied an analytical model for a radio-frequency sheath driven by a single frequency, but in recent years interest has been increasing in radio-frequency discharges excited by increasingly complex wave forms. There has been limited success in generalizing the Lieberman model in this direction, because of mathematical complexities. So there is essentially no sheath model available to describe many modern experiments. In this paper we present a new analytical sheath model, based on a simpler mathematical framework than that of Lieberman. For the single frequency case, this model yields scaling laws that are identical in form to those of Lieberman, differing only by numerical coefficients close to one. However, the new model may be straightforwardly solved for arbitrary current waveforms, and may be used to derive scaling laws for such complex waveforms. In this paper, we will describe the model and present some illustrative examples.

  4. O transtorno bipolar na mulher Bipolar disorder in women

    Directory of Open Access Journals (Sweden)

    Alexandro de Borja Gonçalves Guerra

    2005-01-01

    Full Text Available Diferenças sexuais, descritas em vários transtornos psiquiátricos, também parecem estar presentes no transtorno afetivo bipolar (TAB. A prevalência do TAB tipo I se distribui igualmente entre mulheres e homens. Mulheres parecem estar sujeitas a um risco maior de ciclagem rápida e mania mista, condições que fariam do TAB um transtorno com curso mais prejudicial no sexo feminino. Uma diátese depressiva mais marcante, uso excessivo de antidepressivos e diferenças hormonais surgem como hipóteses para explicar essas diferenças fenomenológicas, apesar das quais, mulheres e homens parecem responder igualmente ao tratamento medicamentoso. A indicação de anticonvulsivantes como primeira escolha em mulheres é controversa, a não ser para o tratamento da mania mista e, talvez, da ciclagem rápida. O tratamento do TAB na gravidez deve levar em conta tanto os riscos de exposição aos medicamentos quanto à doença materna. A profilaxia do TAB no puerpério está fortemente indicada em decorrência do grande risco de recorrência da doença nesse período. Embora, de modo geral, as medicações psicotrópicas estejam contra-indicadas durante a amamentação, entre os estabilizadores do humor, a carbamazepina e o valproato são mais seguros do que o lítio. Mais estudos são necessários para a confirmação das diferenças de curso do TAB entre mulheres e homens e a investigação de possíveis diferenças na efetividade dos tratamentos.Gender differences, described in several psychiatric disorders, seem to be also present in bipolar disorder (BD. The prevalence of bipolar I disorder is equally distributed between women and men. Women seem to be at higher risk for rapid cycling and mixed mania, conditions that could make BD a disorder with a more severe course in the female sex. A marked depressive diathesis among women, greatest use of antidepressants and hormonal differences have been mentioned as hypotheses to explain these

  5. Image-guided radiofrequency ablation of renal cell carcinoma

    International Nuclear Information System (INIS)

    Boss, Andreas; Clasen, Stephan; Pereira, Philippe L.; Kuczyk, Markus; Schick, Fritz

    2007-01-01

    The incidence of renal cell carcinoma is rising with the increased number of incidental detection of small tumours. During the past few years, percutaneous imaging-guided radiofrequency ablation has evolved as a minimally invasive treatment of small unresectable renal tumours offering reduced patient morbidity and overall health care costs. In radiofrequency ablation, thermal energy is deposited into a targeted tumour by means of a radiofrequency applicator. In recent studies, radiofrequency ablation was shown to be an effective and safe modality for local destruction of renal cell carcinoma. Radiofrequency applicator navigation can be performed via ultrasound, computed tomography or magnetic resonance guidance; however, ultrasound seems less favourable because of the absence of monitoring capabilities during ablation. On-line monitoring of treatment outcome can only be performed with magnetic resonance imaging giving the possibility of eventual applicator repositioning to ablate visible residual tumour tissue. Long-term follow-up is crucial to assess completeness of tumour ablation. New developments in ablation technology and radiological equipment will further increase the indication field for radiofrequency ablation of renal cell carcinoma. Altogether, radiofrequency ablation seems to be a promising new modality for the minimally invasive treatment of renal cell carcinoma, which was demonstrated to exhibit high short-term effectiveness. (orig.)

  6. Wireless Chalcogenide Nanoionic-Based Radio-Frequency Switch

    Science.gov (United States)

    Nessel, James; Miranda, Felix

    2013-01-01

    A new nonvolatile nanoionic switch is powered and controlled through wireless radio-frequency (RF) transmission. A thin layer of chalcogenide glass doped with a metal ion, such as silver, comprises the operational portion of the switch. For the switch to function, an oxidizable electrode is made positive (anode) with respect to an opposing electrode (cathode) when sufficient bias, typically on the order of a few tenths of a volt or more, is applied. This action causes the metal ions to flow toward the cathode through a coordinated hopping mechanism. At the cathode, a reduction reaction occurs to form a metal deposit. This metal deposit creates a conductive path that bridges the gap between electrodes to turn the switch on. Once this conductive path is formed, no further power is required to maintain it. To reverse this process, the metal deposit is made positive with respect to the original oxidizable electrode, causing the dissolution of the metal bridge thereby turning the switch off. Once the metal deposit has been completely dissolved, the process self-terminates. This switching process features the following attributes. It requires very little to change states (i.e., on and off). Furthermore, no power is required to maintain the states; hence, the state of the switch is nonvolatile. Because of these attributes the integration of a rectenna to provide the necessary power and control is unique to this embodiment. A rectenna, or rectifying antenna, generates DC power from an incident RF signal. The low voltages and power required for the nanoionic switch control are easily generated from this system and provide the switch with a novel capability to be operated and powered from an external wireless device. In one realization, an RF signal of a specific frequency can be used to set the switch into an off state, while another frequency can be used to set the switch to an on state. The wireless, miniaturized, and nomoving- part features of this switch make it

  7. Clinical, Demographic, and Familial Correlates of Bipolar Spectrum Disorders among Offspring of Parents with Bipolar Disorder

    Science.gov (United States)

    Goldstein, Benjamin I.; Shamseddeen, Wael; Axelson, David A.; Kalas, Cathy; Monk, Kelly; Brent, David A.; Kupfer, David J.; Birmaher, Boris

    2010-01-01

    Objective: Despite increased risk, most offspring of parents with bipolar disorder (BP) do not manifest BP. The identification of risk factors for BP among offspring could improve preventive and treatment strategies. We examined this topic in the Pittsburgh Bipolar Offspring Study (BIOS). Method: Subjects included 388 offspring, ages 7-17 years,…

  8. Modeling of charge transport in ion bipolar junction transistors.

    Science.gov (United States)

    Volkov, Anton V; Tybrandt, Klas; Berggren, Magnus; Zozoulenko, Igor V

    2014-06-17

    Spatiotemporal control of the complex chemical microenvironment is of great importance to many fields within life science. One way to facilitate such control is to construct delivery circuits, comprising arrays of dispensing outlets, for ions and charged biomolecules based on ionic transistors. This allows for addressability of ionic signals, which opens up for spatiotemporally controlled delivery in a highly complex manner. One class of ionic transistors, the ion bipolar junction transistors (IBJTs), is especially attractive for these applications because these transistors are functional at physiological conditions and have been employed to modulate the delivery of neurotransmitters to regulate signaling in neuronal cells. Further, the first integrated complementary ionic circuits were recently developed on the basis of these ionic transistors. However, a detailed understanding of the device physics of these transistors is still lacking and hampers further development of components and circuits. Here, we report on the modeling of IBJTs using Poisson's and Nernst-Planck equations and the finite element method. A two-dimensional model of the device is employed that successfully reproduces the main characteristics of the measurement data. On the basis of the detailed concentration and potential profiles provided by the model, the different modes of operation of the transistor are analyzed as well as the transitions between the different modes. The model correctly predicts the measured threshold voltage, which is explained in terms of membrane potentials. All in all, the results provide the basis for a detailed understanding of IBJT operation. This new knowledge is employed to discuss potential improvements of ion bipolar junction transistors in terms of miniaturization and device parameters.

  9. [Circadian markers and genes in bipolar disorder].

    Science.gov (United States)

    Yeim, S; Boudebesse, C; Etain, B; Belliviera, F

    2015-09-01

    Bipolar disorder is a severe and complex multifactorial disease, characterized by alternance of acute episodes of depression and mania/hypomania, interspaced by euthymic periods. The etiological determinants of bipolar disorder yet, are still poorly understood. For the last 30 years, chronobiology is an important field of investigation to better understand the pathophysiology of bipolar disorder. We conducted a review using Medline, ISI Database, EMBase, PsyInfo up to January 2015, using the following keywords combinations: "mood disorder", "bipolar disorder", "depression", "unipolar disorder", "major depressive disorder", "affective disorder", for psychiatric conditions; and "circadian rhythms", "circadian markers", "circadian gene", "clock gene", "melatonin" for circadian rhythms. The search critera was presence of word in any field of the article. Quantitative and qualitative circadian abnormalities are associated with bipolar disorders both during acute episodes and euthymic periods, suggesting that these altered circadian rhythms may represent biological trait markers of the disorder. These circadian dysfunctions were assessed by various validated tools including polysomnography, actigraphy, sleep diaries, chronotype assessments and blood melatonin/cortisol measures. Other altered endogenous circadian activities have also been reported in bipolar patients, such as hormones secretion, core body temperature or fibroblasts activity. Moreover, these markers were also altered in healthy relatives of bipolar patients, suggesting a degree of heritability. Several genetic association studies have also showed associations between multiple circadian genes and bipolar disorder, such as CLOCK, ARTNL1, GSK3β, PER3, NPAS2, NR1D1, TIMELESS, RORA, RORB, and CSNK1ε. Thus, these circadian gene variants may contribute to the genetic susceptibility of the disease. Furthermore, the study of the clock system may help to better understand some phenotypic aspects like the

  10. Hardness Assurance Techniques for New Generation COTS Devices

    Science.gov (United States)

    Lee, C. I.; Rax, B. G.; Johnston, A. H.

    1996-01-01

    Hardness Assurance (HA) techniques and total dose radiation characterization data for new generation linear and COTS devices from various manufacturers are presented. A bipolar op amp showed significant degradation at HDR, not at low dose rate environment. New generation low-power op amps showed more degradation at low voltage applications. HA test techniques for COTS devices are presented in this paper.

  11. Electrical effects of transient neutron irradiation of silicon devices

    International Nuclear Information System (INIS)

    Hjalmarson, H.P.; Pease, R.L.; Van Ginhoven, R.M.; Schultz, P.A.; Modine, N.A.

    2007-01-01

    The key effects of combined transient neutron and ionizing radiation on silicon diodes and bipolar junctions transistors are described. The results show that interstitial defect reactions dominate the annealing effects in the first stage of annealing for certain devices. Furthermore, the results show that oxide trapped charge can influence the effects of bulk silicon displacement damage for particular devices

  12. Experimental study of a high intensity radio-frequency cooler

    Directory of Open Access Journals (Sweden)

    Ramzi Boussaid

    2015-07-01

    Full Text Available Within the framework of the DESIR/SPIRAL-2 project, a radio-frequency quadrupole cooler named SHIRaC has been studied. SHIRaC is a key device of SPIRAL-2, designed to enhance the beam quality required by DESIR. The preliminary study and development of this device has been carried out at Laboratoire de Physique Corpusculaire de CAEN (LPC Caen, France. The goal of this paper is to present the experimental studies conducted on a SHIRaC prototype. The main peculiarity of this cooler is its efficient handling and cooling of ion beams with currents going up as high as 1  μA which has never before been achieved in any of the previous coolers. Much effort has been made lately into these studies for development of appropriate optics, vacuum and rf systems which allow cooling of beams of large emittance (∼80π  mm mrad and high current. The dependencies of SHIRaC’s transmission and the cooled beam parameters in terms of geometrical transverse emittance and the longitudinal energy spread have also been discussed. Investigation of beam purity at optimum cooling condition has also been done. Results from the experiments indicate that an emittance reduction of less than 2.5π  mm mrad and a longitudinal energy spread reduction of less than 4 eV are obtained with more than 70% of ion transmission. The emittance is at expected values whereas the energy spread is not.

  13. Decision making in euthymic bipolar I and bipolar II disorders.

    Science.gov (United States)

    Martino, D J; Strejilevich, S A; Torralva, T; Manes, F

    2011-06-01

    The main aim of this study was to compare a large population of patients with bipolar disorder (BD) types I and II strictly defined as euthymic with healthy controls on measures of decision making. An additional aim was to compare performance on a decision-making task between patients with and without a history of suicide attempt. Eighty-five euthymic patients with BD-I or BD-II and 34 healthy controls were included. All subjects completed tests to assess verbal memory, attention and executive functions, and a decision-making paradigm (the Iowa Gambling Task, IGT). Both groups of patients had worse performance than healthy controls on measures of verbal memory, attention and executive function. No significant differences were found between BD-I, BD-II and healthy controls on measures of decision making. By contrast, patients with a history of suicide attempt had lower performance in the IGT than patients without a history of suicide attempt. Patients with euthymic BD-I and BD-II had intact decision-making abilities, suggesting that this does not represent a reliable trait marker of the disorder. In addition, our results provide further evidence of an association between impairments in decision making and vulnerability to suicidal behavior.

  14. Clinical application and developmental trend of radiofrequency ablation technology

    International Nuclear Information System (INIS)

    Chen Dongfeng

    2009-01-01

    For recent two decades, radiofrequency ablation technology has made great progress in the field of the treatment for neoplasm. At the very beginning, radiofrequency ablation was adopted in treating the hepatic carcinoma, and since then it has been gradually practiced in treating malignancies of lung, bone, kidney, breast, prostate and other solid tumors. Statistical report of the year 2008 has indicated that in the aspect of similar therapeutic measures radiofrequency ablation therapy for tumors holds a 9% market share. Moreover, in the coming years the clinical use of this kind of therapy for tumors will be steadily increasing by 13% every year. (authors)

  15. Effects of electrode material and configuration on the characteristics of planar resistive switching devices

    KAUST Repository

    Peng, H.Y.; Pu, L.; Wu, J.C.; Cha, Dong Kyu; Hong, J.H.; Lin, W.N.; Li, Yangyang; Ding, Junfeng; David, A.; Li, K.; Wu, Tao

    2013-01-01

    We report that electrode engineering, particularly tailoring the metal work function, measurement configuration and geometric shape, has significant effects on the bipolar resistive switching (RS) in lateral memory devices based on self-doped SrTiO3

  16. Particle Agglomeration in Bipolar Barb Agglomerator Under AC Electric Field

    International Nuclear Information System (INIS)

    Huang Chao; Ma Xiuqin; Sun Youshan; Wang Meiyan; Zhang Changping; Lou Yueya

    2015-01-01

    The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious. To improve agglomeration effectiveness of fine particles, a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed. The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0 μm under applied AC electric field. An optimal condition for achieving better agglomeration effectiveness was found to be as follows: flue gas flow velocity of 3.00 m/s, particle concentration of 2.00 g/m 3 , output voltage of 35 kV and length of the barb of 16 mm. In addition, 4.0–6.0 μm particles have the best effectiveness with the variation of particle volume occupancy of −3.2. (paper)

  17. Particle Agglomeration in Bipolar Barb Agglomerator Under AC Electric Field

    Science.gov (United States)

    Huang, Chao; Ma, Xiuqin; Sun, Youshan; Wang, Meiyan; Zhang, Changping; Lou, Yueya

    2015-04-01

    The development of an efficient technology for removing fine particles in flue gas is essential as the haze is becoming more and more serious. To improve agglomeration effectiveness of fine particles, a dual zone electric agglomeration device consisting of a charging chamber and an agglomeration chamber with bipolar barb electrodes was developed. The bipolar barb electric agglomerator with a polar distance of 200 mm demonstrates good agglomeration effectiveness for particles with a size less than 8.0 μm under applied AC electric field. An optimal condition for achieving better agglomeration effectiveness was found to be as follows: flue gas flow velocity of 3.00 m/s, particle concentration of 2.00 g/m3, output voltage of 35 kV and length of the barb of 16 mm. In addition, 4.0-6.0 μm particles have the best effectiveness with the variation of particle volume occupancy of -3.2. supported by the Key Technology R&D Program of Hebei, China (No. 13211207D)

  18. The International Society for Bipolar Disorders (ISBD) Task Force Report on Antidepressant Use in Bipolar Disorders

    Science.gov (United States)

    Pacchiarotti, Isabella; Bond, David J.; Baldessarini, Ross J.; Nolen, Willem A.; Grunze, Heinz; Licht, Rasmus W.; Post, Robert M.; Berk, Michael; Goodwin, Guy M.; Sachs, Gary S.; Tondo, Leonardo; Findling, Robert L.; Youngstrom, Eric A.; Tohen, Mauricio; Undurraga, Juan; González-Pinto, Ana; Goldberg, Joseph F.; Yildiz, Ayşegül; Altshuler, Lori L.; Calabrese, Joseph R.; Mitchell, Philip B.; Thase, Michael E.; Koukopoulos, Athanasios; Colom, Francesc; Frye, Mark A.; Malhi, Gin S.; Fountoulakis, Konstantinos N.; Vázquez, Gustavo; Perlis, Roy H.; Ketter, Terence A.; Cassidy, Frederick; Akiskal, Hagop; Azorin, Jean-Michel; Valentí, Marc; Mazzei, Diego Hidalgo; Lafer, Beny; Kato, Tadafumi; Mazzarini, Lorenzo; Martínez-Aran, Anabel; Parker, Gordon; Souery, Daniel; Özerdem, Ayşegül; McElroy, Susan L.; Girardi, Paolo; Bauer, Michael; Yatham, Lakshmi N.; Zarate, Carlos A.; Nierenberg, Andrew A.; Birmaher, Boris; Kanba, Shigenobu; El-Mallakh, Rif S.; Serretti, Alessandro; Rihmer, Zoltan; Young, Allan H.; Kotzalidis, Georgios D.; MacQueen, Glenda M.; Bowden, Charles L.; Ghaemi, S. Nassir; Lopez-Jaramillo, Carlos; Rybakowski, Janusz; Ha, Kyooseob; Perugi, Giulio; Kasper, Siegfried; Amsterdam, Jay D.; Hirschfeld, Robert M.; Kapczinski, Flávio; Vieta, Eduard

    2014-01-01

    Objective The risk-benefit profile of antidepressant medications in bipolar disorder is controversial. When conclusive evidence is lacking, expert consensus can guide treatment decisions. The International Society for Bipolar Disorders (ISBD) convened a task force to seek consensus recommendations on the use of antidepressants in bipolar disorders. Method An expert task force iteratively developed consensus through serial consensus-based revisions using the Delphi method. Initial survey items were based on systematic review of the literature. Subsequent surveys included new or reworded items and items that needed to be rerated. This process resulted in the final ISBD Task Force clinical recommendations on antidepressant use in bipolar disorder. Results There is striking incongruity between the wide use of and the weak evidence base for the efficacy and safety of antidepressant drugs in bipolar disorder. Few well-designed, long-term trials of prophylactic benefits have been conducted, and there is insufficient evidence for treatment benefits with antidepressants combined with mood stabilizers. A major concern is the risk for mood switch to hypomania, mania, and mixed states. Integrating the evidence and the experience of the task force members, a consensus was reached on 12 statements on the use of antidepressants in bipolar disorder. Conclusions Because of limited data, the task force could not make broad statements endorsing antidepressant use but acknowledged that individual bipolar patients may benefit from antidepressants. Regarding safety, serotonin reuptake inhibitors and bupropion may have lower rates of manic switch than tricyclic and tetracyclic antidepressants and norepinephrine-serotonin reuptake inhibitors. The frequency and severity of antidepressant-associated mood elevations appear to be greater in bipolar I than bipolar II disorder. Hence, in bipolar I patients antidepressants should be prescribed only as an adjunct to mood-stabilizing medications

  19. Bipolar postpartum depression: An update and recommendations.

    Science.gov (United States)

    Sharma, Verinder; Doobay, Minakshi; Baczynski, Christine

    2017-09-01

    Over the past few years there has been a surge of interest in the study of bipolar postpartum depression (PPD); however, questions remain about its prevalence, screening, clinical features, and treatment. Three electronic databases, MEDLINE/PubMed (1966-2016), PsycINFO (1806-2016), and the Cochrane Database of Systematic Reviews, were searched using a combination of the keywords bipolar, depression, postpartum, peripartum, prevalence, screening, diagnosis, treatment, drugs, and psychotherapy. The reference lists of articles identified were also searched. All relevant articles published in English were included. Depending on the population studied, 21.4-54% of women with PPD have a diagnosis of bipolar disorder (BD). Characteristic clinical features include younger age at illness onset, first onset of depression after childbirth, onset immediately after delivery, atypical depressive symptoms, psychotic features, mixed features, and history of BD in first-degree family members. Treatment should be guided by symptom acuity, safety concerns, the patient's response to past treatments, drug tolerability, and breastfeeding preference. In the absence of controlled treatment data, preference should be given to drugs normally indicated for bipolar depression including lithium, quetiapine and lamotrigine. Although antidepressants have been studied in combination with mood stabilizers in bipolar depression, these drugs should be avoided due to likelihood of elevated risk of induction of manic symptoms in the postpartum period. In the postpartum period, bipolar PPD is common, can be differentiated from unipolar PPD, and needs to be identified promptly in order to expedite appropriate treatment. Future studies on pharmacotherapy and psychotherapy should focus on the acute and preventative treatment of bipolar PPD. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Anxiety, stress and perfectionism in bipolar disorder.

    Science.gov (United States)

    Corry, Justine; Green, Melissa; Roberts, Gloria; Frankland, Andrew; Wright, Adam; Lau, Phoebe; Loo, Colleen; Breakspear, Michael; Mitchell, Philip B

    2013-12-01

    Previous reports have highlighted perfectionism and related cognitive styles as a psychological risk factor for stress and anxiety symptoms as well as for the development of bipolar disorder symptoms. The anxiety disorders are highly comorbid with bipolar disorder but the mechanisms that underpin this comorbidity are yet to be determined. Measures of depressive, (hypo)manic, anxiety and stress symptoms and perfectionistic cognitive style were completed by a sample of 142 patients with bipolar disorder. Mediation models were used to explore the hypotheses that anxiety and stress symptoms would mediate relationships between perfectionistic cognitive styles, and bipolar disorder symptoms. Stress and anxiety both significantly mediated the relationship between both self-critical perfectionism and goal attainment values and bipolar depressive symptoms. Goal attainment values were not significantly related to hypomanic symptoms. Stress and anxiety symptoms did not significantly mediate the relationship between self-critical perfectionism and (hypo)manic symptoms. 1. These data are cross-sectional; hence the causality implied in the mediation models can only be inferred. 2. The clinic patients were less likely to present with (hypo)manic symptoms and therefore the reduced variability in the data may have contributed to the null findings for the mediation models with (hypo) manic symptoms. 3. Those patients who were experiencing current (hypo)manic symptoms may have answered the cognitive styles questionnaires differently than when euthymic. These findings highlight a plausible mechanism to understand the relationship between bipolar disorder and the anxiety disorders. Targeting self-critical perfectionism in the psychological treatment of bipolar disorder when there is anxiety comorbidity may result in more parsimonious treatments. © 2013 Published by Elsevier B.V.

  1. Big data for bipolar disorder.

    Science.gov (United States)

    Monteith, Scott; Glenn, Tasha; Geddes, John; Whybrow, Peter C; Bauer, Michael

    2016-12-01

    The delivery of psychiatric care is changing with a new emphasis on integrated care, preventative measures, population health, and the biological basis of disease. Fundamental to this transformation are big data and advances in the ability to analyze these data. The impact of big data on the routine treatment of bipolar disorder today and in the near future is discussed, with examples that relate to health policy, the discovery of new associations, and the study of rare events. The primary sources of big data today are electronic medical records (EMR), claims, and registry data from providers and payers. In the near future, data created by patients from active monitoring, passive monitoring of Internet and smartphone activities, and from sensors may be integrated with the EMR. Diverse data sources from outside of medicine, such as government financial data, will be linked for research. Over the long term, genetic and imaging data will be integrated with the EMR, and there will be more emphasis on predictive models. Many technical challenges remain when analyzing big data that relates to size, heterogeneity, complexity, and unstructured text data in the EMR. Human judgement and subject matter expertise are critical parts of big data analysis, and the active participation of psychiatrists is needed throughout the analytical process.

  2. Radiofrequency contact currents: sensory responses and dosimetry

    International Nuclear Information System (INIS)

    Kavet, Robert; Tell, R.A.; Olsen, R.G.

    2014-01-01

    The process of setting science-based exposure standards (or guidelines) for radiofrequency (RF) contact current exposure has been disadvantaged by a lack of relevant data. The authors first review the essential features and results of the available studies and illustrate the apparent discrepancies among them. Then, they examine the manner in which current was administered in these studies and suggest as to how the physical relationship of a contacting finger to the current electrode may play a role in affecting sensory thresholds specific to those configurations. A major factor in this analysis relates to whether current density is uniformly distributed across the contact area or whether an electrode's 'edge effects' enhance currents with a net effect of decreasing apparent thresholds, when expressed as the bulk current entering a subject. For an exposure with a clear hazard potential, thresholds of human sensory response to RF currents require further investigation. (authors)

  3. LAPAROSCOPIC NEPHRECTOMY USING RADIOFREQUENCY THERMAL ABLATION

    Directory of Open Access Journals (Sweden)

    B. Ya. Alekseev

    2012-01-01

    Full Text Available The wide use of current diagnostic techniques, such as ultrasound study, computed tomography, and magnetic resonance imaging, has led to significantly increased detection rates for disease in its early stages. This gave rise to a change in the standards for the treatment of locally advanced renal cell carcinoma (RCC. Laparoscopic nephrectomy (LN has recently become the standard treatment of locally advanced RCC in the clinics having much experience with laparoscopic surgery. The chief drawback of LN is difficulties in maintaining intraoperative hemostasis and a need for creating renal tissue ischemia. The paper gives the intermediate results of application of the new procedure of LN using radiofrequency thermal ablation in patients with non-ischemic early-stage RCC.

  4. Emerging indications of endoscopic radiofrequency ablation

    Science.gov (United States)

    Becq, Aymeric; Camus, Marine; Rahmi, Gabriel; de Parades, Vincent; Marteau, Philippe

    2015-01-01

    Introduction Radiofrequency ablation (RFA) is a well-validated treatment of dysplastic Barrett's esophagus. Other indications of endoscopic RFA are under evaluation. Results Four prospective studies (total 69 patients) have shown that RFA achieved complete remission of early esophageal squamous intra-epithelial neoplasia at a rate of 80%, but with a substantial risk of stricture. In the setting of gastric antral vascular ectasia, two prospective monocenter studies, and a retrospective multicenter study, (total 51 patients), suggest that RFA is efficacious in terms of reducing transfusion dependency. In the setting of chronic hemorrhagic radiation proctopathy, a prospective monocenter study and a retrospective multicenter study (total 56 patients) suggest that RFA is an efficient treatment. A retrospective comparative study (64 patients) suggests that RFA improves stents patency in malignant biliary strictures. Conclusions Endoscopic RFA is an upcoming treatment modality in early esophageal squamous intra-epithelial neoplasia, as well as in gastric, rectal, and biliary diseases. PMID:26279839

  5. Radiofrequency encoded angular-resolved light scattering

    DEFF Research Database (Denmark)

    Buckley, Brandon W.; Akbari, Najva; Diebold, Eric D.

    2015-01-01

    The sensitive, specific, and label-free classification of microscopic cells and organisms is one of the outstanding problems in biology. Today, instruments such as the flow cytometer use a combination of light scatter measurements at two distinct angles to infer the size and internal complexity...... of cells at rates of more than 10,000 per second. However, by examining the entire angular light scattering spectrum it is possible to classify cells with higher resolution and specificity. Current approaches to performing these angular spectrum measurements all have significant throughput limitations...... Encoded Angular-resolved Light Scattering (REALS), this technique multiplexes angular light scattering in the radiofrequency domain, such that a single photodetector captures the entire scattering spectrum from a particle over approximately 100 discrete incident angles on a single shot basis. As a proof...

  6. Optical generation of radio-frequency power

    International Nuclear Information System (INIS)

    Hietala, V.M.; Vawter, G.A.; Brennan, T.M.; Hammons, B.E.; Meyer, W.J.

    1994-11-01

    An optical technique for high-power radio-frequency (RF) signal generation is described. The technique uses a unique photodetector based on a traveling-wave design driven by an appropriately modulated light source. The traveling-wave photodetector (TWPD) exhibits simultaneously a theoretical quantum efficiency approaching 100 % and a very large electrical bandwidth. Additionally, it is capable of dissipating the high-power levels required for the RF generation technique. The modulated light source is formed by either the beating together of two lasers or by the direct modulation of a light source. A system example is given which predicts RF power levels of 100's of mW's at millimeter wave frequencies with a theoretical ''wall-plug'' efficiency approaching 34%

  7. Radiofrequency identification for inventory in neurointerventional practice.

    Science.gov (United States)

    Byers, Ernest; Gomez, Max A; Sheridan, Robert M; Orr, Nelson W; Hirsch, Joshua A

    2011-03-01

    Implementations of radiofrequency identification (RFID) systems within hospital settings are not unique or without controversy. To date, little consideration has been given to use of this technology in clinical interventional radiologic practice. The potential financial advantages coupled with benefits to quality and safety and increases in staff satisfaction are considerable. The authors outline these advantages by enabling readers to broadly consider the systemic perspective of implementing RFID technology with an associated vision toward downstream growth. Furthermore, the authors demonstrate the benefits of RFID technology integration in reducing cost and increasing quality assurance and the on-time delivery of services. Implementing RFID requires commitment from frontline technologist staff members to work collaboratively with management and external vendors. Ultimately, the authors believe this technology can positively influence patient care. Copyright © 2011 American College of Radiology. Published by Elsevier Inc. All rights reserved.

  8. Radiofrequency Electromagnetic Field Map of Timisoara

    Science.gov (United States)

    Stefu, N.; Solyom, I.; Arama, A.

    2015-12-01

    There are many electromagnetic field (EMF) sources nowadays acting simultaneously, especially in urban areas, making the theoretical estimation of electromagnetic power at ground level very difficult. This paper reports on EMF maps built with measurements collected in Timisoara, at various radiofrequencies. A grid of 15×15 squares was built (approximate resolution 400m x 400m) and measurements of the average and maximum values of the electric field E, magnetic field H and total power density S at 0.9, 1.8 and 2.4 GHz were collected in every node of the grid. Positions of the nodes in terms of latitude and longitude were also collected. Maps were built presenting the spatial distribution of the measured quantities over Timisoara. Potential influences of EMF on public health are discussed.

  9. Freescale Sdn Bhd: Monitoring Radiofrequency Assessment

    International Nuclear Information System (INIS)

    Wan Saffiey Wan Abdullah; Noor Ezati Shuib; Rozaimah Abdul Rahim; Pasupathy, E.; Muhammad Yusri Yahaya

    2015-01-01

    Freescale Semiconductor (M) Sdn Bhd, requested the assistance of Malaysian Nuclear Agency (Nuclear Malaysia) to conduct an electromagnetic radiation (Radiofrequency Radiation) measurements around its facilities at Freescale Semiconductor (M) Sdn Bhd, 2, Jalan SS8/2, Sungai Wai Free Industrial Zone, 47300 Petaling Jaya, Selangor. Nuclear Agency Non-Ionising Radiation (NIR) Group carried out the measurement on 30th July 2012. In carrying out the work, the Group was assisted by Mr Daniel. The main objectives of the measurement were to assess the presence of electromagnetic radiation (RF field) in an accessible work places within and around the facilities and to advise the company on outcomes of the assessment and measurement based on international recommendations of standard guidelines issued by Malaysian Communication and Multimedia Commission (MCMC) and International Commission on Non-Ionising Radiation Protection (ICNIRP). (author)

  10. Radio-frequency quadrupole linear accelerator

    International Nuclear Information System (INIS)

    Wangler, T.P.; Stokes, R.H.

    1980-01-01

    The radio-frequency quadrupole (RFQ) is a new linear accelerator concept in which rf electric fields are used to focus, bunch, and accelerate the beam. Because the RFQ can provide strong focusing at low velocities, it can capture a high-current dc ion beam from a low-voltage source and accelerate it to an energy of 1 MeV/nucleon within a distance of a few meters. A recent experimental test at the Los Alamos Scientific Laboratory (LASL) has confirmed the expected performance of this structure and has stimulated interest in a wide variety of applications. The general properties of the RFQ are reviewed and examples of applications of this new accelerator are presented

  11. Bipolar pulse generator for intense pulsed ion beam accelerator

    International Nuclear Information System (INIS)

    Ito, H.; Igawa, K.; Kitamura, I.; Masugata, K.

    2007-01-01

    A new type of pulsed ion beam accelerator named ''bipolar pulse accelerator'' (BPA) has been proposed in order to improve the purity of intense pulsed ion beams. To confirm the principle of the BPA, we developed a bipolar pulse generator for the bipolar pulse experiment, which consists of a Marx generator and a pulse forming line (PFL) with a rail gap switch on its end. In this article, we report the first experimental result of the bipolar pulse and evaluate the electrical characteristics of the bipolar pulse generator. When the bipolar pulse generator was operated at 70% of the full charge condition of the PFL, the bipolar pulse with the first (-138 kV, 72 ns) and the second pulse (+130 kV, 70 ns) was successfully obtained. The evaluation of the electrical characteristics indicates that the developed generator can produce the bipolar pulse with fast rise time and sharp reversing time

  12. Application of Bipolar Fuzzy Sets in Graph Structures

    Directory of Open Access Journals (Sweden)

    Muhammad Akram

    2016-01-01

    Full Text Available A graph structure is a useful tool in solving the combinatorial problems in different areas of computer science and computational intelligence systems. In this paper, we apply the concept of bipolar fuzzy sets to graph structures. We introduce certain notions, including bipolar fuzzy graph structure (BFGS, strong bipolar fuzzy graph structure, bipolar fuzzy Ni-cycle, bipolar fuzzy Ni-tree, bipolar fuzzy Ni-cut vertex, and bipolar fuzzy Ni-bridge, and illustrate these notions by several examples. We study ϕ-complement, self-complement, strong self-complement, and totally strong self-complement in bipolar fuzzy graph structures, and we investigate some of their interesting properties.

  13. Cardiovascular risk factors in outpatients with bipolar disorder

    NARCIS (Netherlands)

    Klumpers, U.M.H.; Boom, K.; Janssen, F.M.G.; Tulen, J.H.M.; Loonen, Anton J. M.

    2004-01-01

    Background: The mortality due to cardiovascular diseases in bipolar patients is much higher than in the general population. It is unclear whether lithium treatment contributes to this cardiovascular morbidity. Methods: The cardiovascular risk factors in outpatients with bipolar disorder on

  14. Cytokines in bipolar disorder vs. healthy control subjects

    DEFF Research Database (Denmark)

    Munkholm, Klaus; Braüner, Julie Vestergaard; Kessing, Lars Vedel

    2013-01-01

    Bipolar disorder may be associated with peripheral immune system dysfunction; however, results in individual studies are conflicting. Our aim was to systematically review evidence of peripheral cytokine alterations in bipolar disorder integrating findings from various affective states....

  15. Assessment of subjective and objective cognitive function in bipolar disorder

    DEFF Research Database (Denmark)

    Demant, Kirsa M; Vinberg, Maj; Kessing, Lars V

    2015-01-01

    Cognitive dysfunction is prevalent in bipolar disorder (BD). However, the evidence regarding the association between subjective cognitive complaints, objective cognitive performance and psychosocial function is sparse and inconsistent. Seventy seven patients with bipolar disorder who presented...

  16. Smartphone-based objective monitoring in bipolar disorder

    DEFF Research Database (Denmark)

    Faurholt-Jepsen, Maria; Bauer, Michael; Kessing, Lars Vedel

    2018-01-01

    , anxiety, substance abuse, eating disorder, schizophrenia and bipolar disorder have been developed and used. The present paper presents the status and findings from studies using automatically generated objective smartphone data in the monitoring of bipolar disorder, and addresses considerations...

  17. Immune activation by casein dietary antigens in bipolar disorder

    NARCIS (Netherlands)

    Severance, E.G.; Dupont, D.; Dickerson, F.B.; Stallings, C.R.; Origoni, A.E.; Krivogorsky, B.; Yang, S.; Haasnoot, W.; Yolken, R.H.

    2010-01-01

    Objectives: Inflammation and other immune processes are increasingly linked to psychiatric diseases. Antigenic triggers specific to bipolar disorder are not yet defined. We tested whether antibodies to bovine milk caseins were associated with bipolar disorder, and whether patients recognized

  18. Bipolar disorder: an update | Outhoff | South African Family Practice

    African Journals Online (AJOL)

    Bipolar disorder, characterised by alternating discrete episodes of (hypo)mania and depression, provides unique diagnostic and treatment challenges. Updated diagnostic (DSM-5) and current pharmacological treatment recommendations are briefly reviewed here. Keywords: bipolar disorder; diagnosis; evidence-based ...

  19. Effect of Mobile Phone Radiofrequency Electromagnetic Fields on ...

    African Journals Online (AJOL)

    olayemitoyin

    Summary: Since cell phones emit radiofrequency electromagnetic fields (EMFs), this study tested the hypothesis that cell phones placed ... mobile phones on autonomic modulation of the heart. ..... Electrocardiogram and Its Technology. J. Am.

  20. Radio-frequency wave enhanced runaway production rate

    International Nuclear Information System (INIS)

    Chan, V.S.; McClain, F.W.

    1983-01-01

    Enhancement of runaway electron production (over that of an Ohmic discharge) can be achieved by the addition of radio-frequency waves. This effect is studied analytically and numerically using a two-dimensional Fokker--Planck quasilinear equation

  1. Administrative norms on radiofrequency radiation for occupationally exposed persons

    International Nuclear Information System (INIS)

    Saxeboel, G.

    1982-01-01

    The report presents a proposal for administrative norms on radiofrequency (RF) radiation for occupationally exposed persons. The norms establish maximum allowable field exposure in a frequency range from 1 MHz too 300 GHz. (RF)

  2. Ion-storage in radiofrequency electric quadrupole field

    International Nuclear Information System (INIS)

    Gheorghe, V.

    1976-01-01

    The confinement of charged particles in a quadrupole radiofrequency electric field are presented. The stability diagrams and phase space trajectories for the quadrupole mass spectrometer and for the ion trap are represented and their main characteristics are discussed. (author)

  3. Process for selected gas oxide removal by radiofrequency catalysts

    Science.gov (United States)

    Cha, Chang Y.

    1993-01-01

    This process to remove gas oxides from flue gas utilizes adsorption on a char bed subsequently followed by radiofrequency catalysis enhancing such removal through selected reactions. Common gas oxides include SO.sub.2 and NO.sub.x.

  4. Nickel hydrogen bipolar battery electrode design

    Science.gov (United States)

    Puglisi, V. J.; Russell, P.; Verrier, D.; Hall, A.

    1985-01-01

    The preferred approach of the NASA development effort in nickel hydrogen battery design utilizes a bipolar plate stacking arrangement to obtain the required voltage-capacity configuration. In a bipolar stack, component designs must take into account not only the typical design considerations such as voltage, capacity and gas management, but also conductivity to the bipolar (i.e., intercell) plate. The nickel and hydrogen electrode development specifically relevant to bipolar cell operation is discussed. Nickel oxide electrodes, having variable type grids and in thicknesses up to .085 inch are being fabricated and characterized to provide a data base. A selection will be made based upon a system level tradeoff. Negative (hydrpogen) electrodes are being screened to select a high performance electrode which can function as a bipolar electrode. Present nickel hydrogen negative electrodes are not capable of conducting current through their cross-section. An electrode was tested which exhibits low charge and discharge polarization voltages and at the same time is conductive. Test data is presented.

  5. Comorbid medical illness in bipolar disorder.

    Science.gov (United States)

    Forty, Liz; Ulanova, Anna; Jones, Lisa; Jones, Ian; Gordon-Smith, Katherine; Fraser, Christine; Farmer, Anne; McGuffin, Peter; Lewis, Cathryn M; Hosang, Georgina M; Rivera, Margarita; Craddock, Nick

    2014-12-01

    Individuals with a mental health disorder appear to be at increased risk of medical illness. To examine rates of medical illnesses in patients with bipolar disorder (n = 1720) and to examine the clinical course of the bipolar illness according to lifetime medical illness burden. Participants recruited within the UK were asked about the lifetime occurrence of 20 medical illnesses, interviewed using the Schedules for Clinical Assessment in Neuropsychiatry (SCAN) and diagnosed according to DSM-IV criteria. We found significantly increased rates of several medical illnesses in our bipolar sample. A high medical illness burden was associated with a history of anxiety disorder, rapid cycling mood episodes, suicide attempts and mood episodes with a typically acute onset. Bipolar disorder is associated with high rates of medical illness. This comorbidity needs to be taken into account by services in order to improve outcomes for patients with bipolar disorder and also in research investigating the aetiology of affective disorder where shared biological pathways may play a role. Royal College of Psychiatrists.

  6. [Drug Abuse Comorbidity in Bipolar Disorder].

    Science.gov (United States)

    Ortiz, Óscar Medina

    2012-06-01

    Drug use among patients with bipolar disorder is greater than the one observed in the general population; psychotic episodes are likely to occur after consumption. This has implications in the prevention, etiology, management, and treatment of the disease. Bipolar disorder pathology is likely to have positive response to pharmacological treatment. Therefore, identifying the strategies with better results to be applied in these patients is fundamental for psychiatrists and primary care physicians. Review literature in order to determine the prevalence and characteristics of drug abuse in patients with bipolar disorder and establish the pharmacological strategies that have produced better results. Literature review. A great variety of studies demonstrate the relationship between bipolar disorder and drug use disorder. These patients are hospitalized more frequently, have an earlier onset of the disease, and present a larger number of depressive episodes and suicide attempts which affect the course of the disease. The drug with better results in the treatment of these patients is Divalproate. Satisfactory results have been also obtained with other mood stabilizers such as carbamazepine, lamotrigine, and the antipsychotic aripiprazole. Substance abuse is present in a large number of patients with bipolar disorder. The Divalproate is the drug that has shown better results in the studies. Copyright © 2012 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.

  7. Family History in Patients with Bipolar Disorder.

    Science.gov (United States)

    Özdemir, Osman; Coşkun, Salih; Aktan Mutlu, Elif; Özdemir, Pınar Güzel; Atli, Abdullah; Yilmaz, Ekrem; Keskin, Sıddık

    2016-09-01

    In this study, we aimed to better understand the genetic transmission of bipolar disorder by examining the family history of patients. Sixty-three patients with bipolar disorder and their families were included. The final sample comprised 156 bipolar patients and their family members. An inclusion criterion was the presence of bipolar disorder history in the family. The diagnosis of other family members was confirmed by analyzing their files, hospital records, and by calling them to the hospital. Sixty-five patients were women (41.6%) and 91 were men (58.3%) (ratio of men/women: 1.40). When analyzing the results in terms of the transition of disease from the mother's or father's side, similar results were obtained: 25 patients were from the mother's side and 25 patients were from the father's side in 63 cases. The results of our study support the fact that a significant relationship exists between the degree of kinship and the heritability of bipolar disorder and, furthermore, that the effect of the maternal and paternal sides is similar on the transmission of genetic susceptibility.

  8. SEU-hardened silicon bipolar and GaAs MESFET SRAM cells using local redundancy techniques

    International Nuclear Information System (INIS)

    Hauser, J.R.

    1992-01-01

    Silicon bipolar and GaAs FET SRAM's have proven to be more difficult to harden with respect to single-event upset mechanisms than have silicon CMOS SRAM's. This is a fundamental property of bipolar and JFET or MESFET device technologies which do not have a high-impedance, nonactive isolation between the control electrode and the current or voltage being controlled. All SEU circuit level hardening techniques applied at the local level must use some type of information storage redundancy so that information loss on one node due to an SEU event can be recovered from information stored elsewhere in the cell. In CMOS technologies, this can be achieved by the use of simple cross-coupling resistors, whereas in bipolar and FET technologies, no such simple approach is possible. Several approaches to the use of local redundancy in bipolar and FET technologies are discussed in this paper. At the expense of increased cell complexity and increased power consumption and write time, several approaches are capable of providing complete SEU hardness at the local cell level

  9. Inflammatory cytokine expression following the use of bipolar electrocoagulation, ultracision harmonic scalpel and cold knife biopsy.

    Science.gov (United States)

    Litta, Pietro; Saccardi, Carlo; Gizzo, Salvatore; Conte, Lorena; Ambrosi, Giulia; Sissi, Claudia; Palumbo, Manlio

    2015-08-01

    Electrical surgical devices may determine tissue damage through lateral thermal spread and activation of inflammatory processes. Several tissue effects are associated with the use of different surgical instruments. The aim of the present study was to compare tissue damage following the application of cold knife biopsy, bipolar electrocoagulation and the ultracision harmonic scalpel, through the analysis of inflammatory gene mediator expression. Three fragments of the round ligament (length 0.5 cm) were obtained from 22 females who had undergone total or subtotal laparoscopic hysterectomy using three different modes of resection: Cold knife biopsy, bipolar electrocoagulation and ultracision harmonic scalpel. The tissue fragments were examined by quantitative polymerase chain reaction (qPCR) analysis of selected cytokines. Gene expression analysis demonstrated large standard deviations due to individual variability among patients and indicated variability in the concentrations of cytokines in the three different samples. The quantity of cytokine mRNA in the cold knife biopsy samples was generally greater than those obtained by other techniques. Tumor necrosis factor-α expression was significantly higher in the sample obtained with the ultracision harmonic scalpel and bipolar electrocoagulation (P=0.033) when compared with cold knife biopsy. The inflammatory response was analyzed by the quantification of gene expression through the use of qPCR. The ultracision harmonic scalpel and bipolar electrocoagulation triggered the inflammatory cascade and resulted in an increased production of cytokines compared with cold knife biopsy.

  10. DEVELOPMENT OF CONTROLLED RECTIFIERS BASED ON THE BIPOLAR WITH STATIC INDUCTION TRANSISTORS (BSIT

    Directory of Open Access Journals (Sweden)

    F. I. Bukashev

    2016-01-01

    Full Text Available Aim. The aim of this study is to develop one of the most perspective semiconductor device suitable for creation and improvement of controlled rectifiers, bipolar static induction transistor.Methods. Considered are the structural and schematic circuit controlled rectifier based on bipolar static induction transistor (BSIT, and the criterion of effectiveness controlled rectifiers - equivalent to the voltage drop.Results. Presented are the study results of controlled rectifier layout on BSIT KT698I. It sets the layout operation at an input voltage of 2.0 V at a frequency up to 750 kHz. The efficiency of the studied layouts at moderate current densities as high as 90 % .Offered is optimization of technological route microelectronic controlled rectifier manufacturing including BSIT and integrated bipolar elements of the scheme management.Conclusion. It is proved that the most efficient use of the bipolar static induction transistor occurs at the low voltage controlled rectifiers 350-400 kHz, at frequencies in conjunction with a low-voltage control circuit.It is proved that the increase of the functional characteristics of the converters is connected to the expansion of the input voltage and output current ranges

  11. The Dutch Bipolar Offspring Study: 12-Year Follow-Up

    OpenAIRE

    Mesman, Esther; Nolen, Willem A.; Reichart, Catrien G.; Wals, Marjolein; Hillegers, Manon N. J.

    2013-01-01

    Objective: Offspring of bipolar parents have a genetically increased risk of developing mood disorders. In a longitudinal study, the authors followed a bipolar offspring cohort from adolescence into adulthood to determine the onset, prevalence, and early course of mood disorders and other psychopathology. Method: The Dutch bipolar offspring cohort is a fixed cohort initiated in 1997 (N=140; age range at baseline, 12-21 years). Bipolar offspring were psychiatrically evaluated at baseline and a...

  12. Rumination in bipolar disorder: evidence for an unquiet mind

    OpenAIRE

    Ghaznavi, Sharmin; Deckersbach, Thilo

    2012-01-01

    Abstract Depression in bipolar disorder has long been thought to be a state characterized by mental inactivity. However, recent research demonstrates that patients with bipolar disorder engage in rumination, a form of self-focused repetitive cognitive activity, in depressed as well as in manic states. While rumination has long been associated with depressed states in major depressive disorder, the finding that patients with bipolar disorder ruminate in manic states is unique to bipolar disord...

  13. Paying attention to radiofrequency ablation therapy for neoplasms

    International Nuclear Information System (INIS)

    Wang Zhongming; Li Linsun

    2010-01-01

    Radiofrequency ablation is an effective treatment for malignant tumors. With the development of imaging technique, it has been widely used in treating different kinds of malignant tumors, such as liver cancer, lung cancer, kidney carcinoma, etc. Radiofrequency ablation has a lot of advantages. As a minimally-invasive, safe and effective treatment with less sufferings and fewer complications, this technique has attracted more and more attention of the experts both at home and abroad. (authors)

  14. Eye examinations of laser and radiofrequency radiation workers

    International Nuclear Information System (INIS)

    Hocking, B.

    1988-01-01

    There are a growing number of uses of lasers and radiofrequency radiation in industry. Because these radiations may lead to various ocular effects, examinations of the eye are required for laser and radiofrequency workers as part of safe working practices. Various issues concerning these examinations are raised for discussion including: handling personal data, placement criteria, data collection, quality control, control data, the load on service providers, and costs

  15. Risk factors for suicide among children and youths with bipolar spectrum and early bipolar disorder.

    Science.gov (United States)

    Rajewska-Rager, Aleksandra; Sibilski, Piotr; Lepczyńska, Natalia

    2015-01-01

    In recent years much attention has been given to determine risk factors for suicide among adults with bipolar disorder. Such studies concerning children and youths, which would also take into account the specificity of the developmental age, are still too few. The ability to identify risk factors for children and youths with mood disorders, as well as the possibility to monitor them, is an essential element in preventing suicidal behaviours. Previous studies have clearly indicated that in the group of patients with an early onset of the bipolar disorder the occurrence of suicidal thoughts and intentions were significantly increased. Identifying the risk of suicide is hindered further by the complexity of the phenomenon, which is a compound interaction of various factors: biological, environmental, sociological, psychological and clinical. This is especially true with young adults suffering from mental illness and presenting a number of other psychopathological symptoms. The following paper introduces and reviews the results of current studies, which analysed the risk factors for suicide among children and youths with bipolar spectrum or already diagnosed with bipolar disorder. For this purpose we conducted the overview of recent years literature available in PubMed/MEDLINE database, including the following search criteria: early onset bipolar disorder, bipolar disorder in children and young people, the spectrum of bipolar disorder, and suicidal ideation, suicidal intent, suicide.

  16. Bipolar resistive switching behaviors of ITO nanowire networks

    Directory of Open Access Journals (Sweden)

    Qiang Li

    2016-02-01

    Full Text Available We have fabricated indium tin oxide (ITO nanowire (NW networks on aluminum electrodes using electron beam evaporation. The Ag/ITO-NW networks/Al capacitor exhibits bipolar resistive switching behavior. The resistive switching characteristics of ITO-NW networks are related to the morphology of NWs. The x-ray photoelectron spectroscopy was used to obtain the chemical nature from the NWs surface, investigating the oxygen vacancy state. A stable switching voltages and a clear memory window were observed in needle-shaped NWs. The ITO-NW networks can be used as a new two-dimensional metal oxide material for the fabrication of high-density memory devices.

  17. Photovoltaic Cells Improvised With Used Bipolar Junction Transistors

    International Nuclear Information System (INIS)

    Akintayo, J. A

    2002-01-01

    The understanding of the underlying principle that the solar cell consists of a p-n junction is exploited to adapt the basic NPN or PNP Bipolar Junction Transistors (BJT) to serve as solar cells. In this mode the in improvised solar cell have employed just the emitter and the base sections with an intact emitter/base junction as the active PN area. The improvised devices tested screened and sorted are wired up in strings, blocks and modules. The photovoltaic modules realised tested as close replica of solar cells with output voltage following insolation level. Further work need be done on the modules to make them generate usable levels of output voltage and current

  18. Total Dose Effects on Bipolar Integrated Circuits at Low Temperature

    Science.gov (United States)

    Johnston, A. H.; Swimm, R. T.; Thorbourn, D. O.

    2012-01-01

    Total dose damage in bipolar integrated circuits is investigated at low temperature, along with the temperature dependence of the electrical parameters of internal transistors. Bandgap narrowing causes the gain of npn transistors to decrease far more at low temperature compared to pnp transistors, due to the large difference in emitter doping concentration. When irradiations are done at temperatures of -140 deg C, no damage occurs until devices are warmed to temperatures above -50 deg C. After warm-up, subsequent cooling shows that damage is then present at low temperature. This can be explained by the very strong temperature dependence of dispersive transport in the continuous-time-random-walk model for hole transport. For linear integrated circuits, low temperature operation is affected by the strong temperature dependence of npn transistors along with the higher sensitivity of lateral and substrate pnp transistors to radiation damage.

  19. On Bipolar Valued Fuzzy k-Ideals in Hermirings

    International Nuclear Information System (INIS)

    Mahmood, T.; Ejaz, A.

    2015-01-01

    In this paper we discuss some results associated with bipolar valued fuzzy k -ideals of hermirings. We also define bipolar valued fuzzy k-intrinsic product and characterize k-hemiregular hermirings by using their bipolar valued fuzzy k -ideals. (author)

  20. Family Functioning and the Course of Adolescent Bipolar Disorder

    Science.gov (United States)

    Sullivan, Aimee E.; Judd, Charles M.; Axelson, David A.; Miklowitz, David J.

    2012-01-01

    The symptoms of bipolar disorder affect and are affected by the functioning of family environments. Little is known, however, about the stability of family functioning among youth with bipolar disorder as they cycle in and out of mood episodes. This study examined family functioning and its relationship to symptoms of adolescent bipolar disorder,…