Alivation (United States)

Microwave energy has been extensively studied and used in various medical applications. Some of them involves the use of generator to generate, transmit, and emit the energy into human body as a mean of therapy. In this case, accurate measurement and/or manipulation of the microwave is necessary in order to ensure safety to the patients. However, this is a challenging task due to the interferences from the reflected waves caused by mismatch at each connection. Time domain analysis (TDA) using a vector network analyzer (VNA) is a commonly employed technique to separate the reflected waves of the antenna from those of the antenna. However, its requirement for sweeping over a broad frequency band renders it impractical for integration within a generator. To address this limitation, we propose a novel method for estimating reflection coefficients utilizing an autoregressive (AR) model. The proposed method offers the advantage of estimating the distance and reflection coefficient of each reflector simultaneously by sweeping over a narrow frequency band and measuring the reflection amplitude and phase. To validate the efficacy of this approach, simulations were conducted, demonstrating that the implemented AR model works correctly. Furthermore, experimental validation was performed with 10 sets of Devices Under Test (DUTs) fabricated. The reflection coefficients at 2.45 GHz were estimated for coaxial-slot antennas in air, water, and isopropyl alcohol (IPA). The error rates of the estimated reflection coefficients were found to be −1.38 ± 3.69% for air, −7.85 ± 17.8% for water, and −0.551 ± 8.29% for IPA, respectively. In the case of water, where even with an error of +2σ from the mean value, the difference between the mean radiated power of DUTs and the estimated one was only 1.37%, indicating that the estimation could be performed with sufficient accuracy. In conclusion, our proposed estimation method is promising for accurate estimation radiated power and detection abnormal conditions in microwave medical devices.

Few treatments are available for individuals with marked treatment-resistant depression (TRD). Evaluate the safety and effectiveness of FDA-approved adjunctive vagus nerve stimulation (VNS) in patients with marked TRD. This 12-month, multicenter, double-blind, sham-controlled trial included 493 adults with marked treatment-resistant major depression who were randomized to active or no-stimulation sham VNS for 12 months. The primary outcome was percent time in response across months 3-12, with response defined as a ≥50% change from baseline on the Montgomery-Åsberg Depression Rating Scale (MADRS). Several secondary endpoints were evaluated. Overall, 88.4% of participants completed the trial. Percent time in MADRS response did not distinguish active from sham VNS. However, ratings from on-site clinicians (Clinical Global Inventory-Impression [CGI-I]), patients (Quick Inventory of Depressive Symptomology-Self Report [QIDS-SR]), and offsite masked raters (Quick Inventory of Depressive Symptomology-Clinician [QIDS-C]) revealed antidepressant benefits significantly favoring active VNS. Active VNS demonstrated significantly more percent time in response on the CGI-I (P=0.004) and QIDS-SR (P=0.049), and significantly more percent time in partial response (PR; symptom improvement ≥30%) on the CGI-I (P<0.001) and QIDS-C (P=0.006) versus sham VNS. Active VNS exceeded sham VNS in rate of dyspnea (P=0.035), a known side effect of VNS. No new adverse events were identified. Percent time in MADRS response did not distinguish the treatment groups, but on multiple instruments time in response and PR showed a positive treatment effect. VNS was found safe and effective in participants with marked TRD.

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive brain stimulation method increasingly used to treat psychiatric disorders, primarily depression. Initial studies suggest that rTMS may help to treat addictions, but evaluation in multicenter randomized controlled trials (RCTs) is needed. We conducted a multicenter double-blind RCT in 262 chronic smokers meeting DSM-5 criteria for tobacco use disorder, who had made at least one prior failed attempt to quit, with 68% having made at least three failed attempts. They received three weeks of dailybilat-eral active or sham rTMS to the lateral prefrontal and insular cortices, followed by once weekly rTMS for three weeks. Each rTMS session was administered following a cue-induced craving procedure, and participants were monitored for a total of six weeks. Those in abstinence were monitored for additional 12 weeks. The primary outcome measure was the four-week continuous quit rate (CQR) until Week 18 in the intent-to-treat efficacy set, as determined by daily smoking diaries and verified by urine cotinine measures. The trial was registered at ClinicalTrials.gov (NCT02126124). In the intent-to-treat analysis set (N=234), the CQR until Week 18 was 19.4% following active and 8.7% following sham rTMS (X2 =5.655, p=0.017). Among completers (N=169), the CQR until Week 18 was 28.0% and 11.7%, respectively (X2 =7.219, p=0.007). The reduction in cigarette consumption and craving was significantly greater in the active than the sham group as early as two weeks into treatment. This study establishes a safe treatment protocol that promotes smoking cessation by stimulating relevant brain circuits. It represents the first large multicenter RCT of brain stimulation in addiction medicine, and has led to the first clearance by the US Food and Drug Administration for rTMS as an aid insmok-ing cessation for adults.