Search Results (52)

Stress significantly impacts our society, making strategies for its mitigation necessary. A possible approach may involve binaural beats (BBs), i.e., an auditory stimulation obtained by presenting pure tones with slightly different frequencies to the user’s ears, resulting in a third phantom beat $\left(f_{BB}\right)$. While studies in the literature investigate the effects of BBs at a constant stimulation frequency, with this pilot study, we present an innovative approach that adapts the beat frequency in real time within the theta range (4.0–8.0 Hz) to reduce acute mental stress. A stress index, obtained from the predictions of a random forest regressor, was considered to adjust the stimulation. The regressor considered features from an electrocardiogram (ECG) and the ECG-derived respiratory signal. Thirteen healthy subjects underwent a stressful protocol involving multiple mental arithmetic tasks during which constant (CBB) or adapted (ABB) stimulation occurred. Task performances like accuracy and reaction times were recorded. The results show that ABBs significantly lowered the average stress index ($p<0.05$) and heart rate ($p<0.05$) compared to CBBs. No statistically significant differences were detected in task performance. The results support the importance of adaptive and personalized approaches for mitigating stress. Future research is necessary to assess the goodness of our proposal, considering a larger sample, different stressors, and an objective and external assessment of stress (e.g., cortisol levels). Full article

Space gravitational wave detection uses a three-satellite formation scheme, with the distance between satellites reaching hundreds of thousands or millions of kilometers. According to the principle of laser heterodyne interferometry, the distance change between the inter-satellite inertial references caused by the gravitational wave event is converted into the phase change of the heterodyne interference signal. The payload for measuring the phase change information is the phasemeter. The mission requires that the phasemeter’s ranging accuracy is 1 picometer, and the corresponding phase measurement accuracy is required to reach 2π μrad/Hz^1/2 @(0.1 mHz–1 Hz). Due to the inter-satellite Doppler effect, the dynamic range of the interference signal frequency reaches 5 MHz to 25 MHz. Due to the sampling jitter noise of the interference signal, it is necessary to suppress the noise through a single pilot tone. This paper introduces the development of the phasemeter, which uses a single pilot tone to suppress sampling jitter noise. The test results show that when the dynamic range of the interference signal frequency is 5 MHz to 25 MHz, the phasemeter meets the mission indicator requirement of 2π μrad/Hz^1/2 @(0.1 mHz–1 Hz). Full article

Background/Objectives: Patient navigation is vital for improving healthcare accessibility and patient experience in China’s public hospitals, where high patient demand meets limited medical resources. Patient navigators (PNs) assist patients through the complex healthcare system, but the lack of standardized training and evaluation hampers their ability to meet patient needs. This study piloted a Competencies Improvement Training Program (CITP) in a tertiary hospital to clarify PN competencies, design a feasible curriculum, assess its efficacy, and share insights with peer hospitals. Methods: The CITP used the Plan–Do–Check–Act (PDCA) framework and designed a curriculum with Miller’s Pyramid Model. Over 6 months, eight sessions were conducted, including theory, case studies, etc. The quasi-experimental design compared PN competencies and patient satisfaction before and after. Multiple instruments measured baseline competencies and program efficacy with a 6-month post-training follow-up. Results: A total of 75 PNs (75%) participated and completed all sessions. A total of 1189 patients were surveyed before training, 495 in the first month after training, and 502 in the 6-month follow-up. The CITP significantly boosted PN competency scores from 90.259 to 95.453, though it dipped to 92.721 by 6 months. Patient satisfaction with PN services improved modestly over 6 months. Challenges in applying theoretical knowledge to practical skills were noted, suggesting differentiated training based on navigator demographics. Patient satisfaction for aspects like politeness and tone was linked to patient age and education. Conclusions: The CITP enhanced PN core competencies and provided an evidence-based curriculum model. Future research should involve larger multi-center populations with longer-term follow-ups to validate the program’s effectiveness across diverse settings. Full article

Background: Treating psychiatric illnesses or influencing mental states with neurofeedback is challenging, likely due to the limited spatial specificity of EEG and the complications arising from the inadequate signal-to-noise ratio reduction of single-trial EEG. Objective: This pilot study aimed to investigate the feasibility of employing a binaural pulse mode-modulation (BPM) device to reduce anxiety by self-regulation. We desired to determine whether anxiety could be significantly reduced or regulated using BPM-type systems. Methods: Sixty adult participants were examined with self-reported anxiety tests (COVID Stress Scale, Generalized Anxiety Disorder 7, Beck Depression Inventory-II), which were completed before treatment, after four weeks, and after 12 weeks post-treatment. This BPM device produced two frequencies which combined to create a binaural pulse through differential auditory tone presentations. The participant calibrated the suitable target tone for optimal treatment efficacy. Each participant adjusted the binaural pulse to enhance the emotional intensity felt when envisioning an experience with comparable emotional significance or while performing a cognitive task while concurrently listening to music. The “treatment” relied on the individual’s regulation of binaural pulses to obtain the desired state. The training concentrated on particular facets of their psychological challenges while listening to an auditory tone, adjusting a knob until the sound amplified the intended emotional state. Another knob was turned to intensify the emotional state associated with distress reduction. Results: On the self-reported measures, the BPM treatment group was significantly better than the sham treatment (control) groups (p < 0.01). These findings indicate that over the four-week intervention period, BPM was similarly effective. On the GAD-7, the significant difference over time was noted before treatment and at the end of treatment for the experimental group, with the average GAD-7 score at the end of treatment being significantly lower (p < 0.01). Conclusions: BPM seems to induce a short-term alteration in self-reported distress levels during therapy. This study’s limitations are examined, and recommendations for future research are provided. Full article

Continuous-variable quantum key distribution (CV-QKD) has been increasingly studied, which offers the advantage of compatibility with modern coherent optical communication systems. In contrast to CV-QKD with a transmitting local oscillator, the local local oscillator CV-QKD avoids the security vulnerabilities of a local oscillator by generating a local oscillator at the receiver. In practice, the frequency offset of the two lasers introduces extra phase noise, which is generally suppressed by various carrier phase recovery algorithms. However, the accuracy of carrier phase recovery can be influenced by the power of the pilot tone, particularly as the transmission distance increases. To further improve accuracy, we propose a method based on the unscented particle filter algorithm, to increase the accuracy of phase estimation, effectively restore the quantum signal and reduce excess noise. In our work, we demonstrated a local local oscillator CV-QKD experiment with a finite-size block of $1\times {10}^8$ under a transmission distance of 50 km. Through our method, we achieved a secret key rate of 525 kbps, which represents a 28% improvement. These results confirm that our proposed method not only improves the accuracy of carrier phase recovery, but also provides a new approach for future research on algorithms for long-distance CV-QKD. Furthermore, our study improves the phase compensation performance, enabling the orthogonal components of the quantum signal to exhibit enhanced symmetry in phase space. Full article

Background/Objectives: Inadequate cardiovascular adaptation during pregnancy impairs endothelial function and vascular resistance, contributing to complications such as pre-eclampsia (PE) and gestational hypertension (GH). Neprilysin (NEP), a protease involved in vascular regulation, has been linked to PE, but its role in endothelial function and vascular adaptation remains unclear. This pilot study investigates the associations between soluble neprilysin (sNEP) and markers of vascular and renal function in high-risk pregnancies without PE. Methods: Observed parameters were analyzed in 29 high-risk pregnant women across early, mid-, and late pregnancy. sNEP levels were analyzed alongside body mass index (BMI), endothelial dysfunction (ADMA), arterial stiffness (pulse wave velocity, PWV), retinal microvasculature (central retinal arteriolar and venular equivalents, CRAE and CRVE), and kidney function markers. The impact of gestational hypertension (GH) and prior smoking on sNEP levels was also evaluated. Results: In early and mid-pregnancy, sNEP was inversely associated with BMI. During mid-pregnancy, sNEP showed a positive correlation with CRAE and an inverse correlation with PWV, suggesting reduced arterial stiffness. By late pregnancy, sNEP was positively associated with glomerular filtration rate and inversely correlated with creatinine and protein levels, reflecting improved kidney function. Women with GH exhibited elevated sNEP, while former smokers had lower sNEP levels in early pregnancy. Conclusions: These findings suggest that sNEP plays a role in vascular and renal adaption during pregnancy, offering new perspectives on vascular tone regulation in high-risk pregnancies. Further research is needed to clarify these mechanisms and their clinical relevance. Full article

Compared with high spectrum efficiency faster-than-Nyquist (FTN) backbone network, an enhanced carrier phase recovery based on dual pilot tones is more sensitive to capital cost in FTN metropolitan areas as well as inter-datacenter optical networks. The use of distributed feedback (DFB) lasers is a way to effectively reduce the cost. However, under high symbol rate FTN systems, equalization-enhanced phase noise (EEPN) induced by a DFB laser with large linewidth will significantly deteriorate the system performance. What is worse, in FTN systems, tight filtering introduces inter-symbol interference so severe that the carrier phase estimation (CPE) algorithm of the FTN systems is more sensitive to EEPN, thus it will lead to a more serious cycle slip problem. In this paper, an enhanced carrier phase recovery based on dual pilot tones is proposed to mitigate EEPN and suppress cycle slip, in which the chromatic dispersion (CD)-aware Tx and LO laser phase noise is estimated, respectively. Offline experiments results under 40 Gbaud polarization multiplexing (PM) 16-quadrature amplitude modulation (QAM) FTN wavelength division multiplexing (FTN-WDM) systems at 0.9 acceleration factor, 5 MHz laser linewidth, and 500 km transmission demonstrate that the proposed algorithm could bring about 0.65 dB improvement of the required SNR for the normalized generalized mutual information of 0.9 compared with the training sequence-based cycle slip suppression carrier phase estimation (TS-CSS) algorithm. Full article

The rising incidence of type 2 diabetes underscores the need for technological innovations aimed at enhancing diabetes management by aiding individuals in monitoring their dietary intake. This has resulted in the development of technologies capable of tracking the timing and content of an individual’s meals. However, the ability to use non-invasive wearables to estimate or classify the carbohydrate content of the food an individual has just consumed remains a relatively unexplored area. This study investigates carbohydrate content classification using postprandial heart rate responses from non-invasive wearables. We designed and developed timeStampr, an iOS application for collecting timestamps essential for data labeling and establishing ground truth. We then conducted a pilot study in controlled, yet naturalistic settings. Data were collected from 23 participants using an Empatica E4 device worn on the upper arm, while each participant consumed either low-carbohydrate or carbohydrate-rich foods. Due to sensor irregularities with dark skin tones and non-compliance with the study’s health criteria, we excluded data from three participants. Finally, we configured and trained a Light Gradient Boosting Machine (LGBM) model for carbohydrate content classification. Our classifiers demonstrated robust performance, with the carbohydrate content classification model consistently achieving at least 84% in accuracy, precision, recall, and AUCROC within a 60 s window. The results of this study demonstrate the potential of postprandial heart rate responses from non-invasive wearables in carbohydrate content classification. Full article

Background: The reduction in joint load is a potential beneficial factor in managing osteoarthritis of the temporomandibular joint (TMJ). This paper aims to compare the effectiveness of the intramuscular injection of botulinum toxin (BTX-A) as an adjunct to TMJ arthrocentesis plus viscosupplementation with arthrocentesis plus viscosupplementation alone in the management of TMJ osteoarthritis. Methods: A pilot clinical retrospective study examined TMJ osteoarthritis treatments. Patients were divided into two groups: Group A received BTX-A injections and arthrocentesis with viscosupplementation, while Group B received only arthrocentesis with viscosupplementation. The study assessed outcomes based on mouth opening (MO), pain at rest (PR), pain at mastication (PF), and masticatory efficiency (ME) at various time points (baseline (T0), 1 week (T1), 2 weeks (T2), 3 weeks (T3), and 4 weeks (T4)) up to 2 months after treatment. Results: The study included two groups, each with five patients. Group A received five weekly sessions of arthrocentesis plus viscosupplementation and a single BTX-A injection during the first arthrocentesis appointment. Group B underwent the five-session protocol of arthrocentesis plus viscosupplementation alone. MO, PF, PR, and ME improved quickly in T2 in both groups, but the improvement was of greater importance over the following weeks and lasted longer in Group A. Conclusions: Arthrocentesis with viscosupplementation associated with BTX-A was found to be more effective than arthrocentesis alone in improving clinical outcomes. This suggests that patients with TMJ osteoarthritis and myofascial pain may benefit from reduced muscle tone and joint load. Full article

Upper-limb spasticity, frequent after central nervous system lesions, is typically treated with botulinum neurotoxin type A (BoNT-A) injections to reduce muscle tone and increase range of motion. However, performing adjunct physical therapy post-BoNT-A can be challenging due to residual weakness or spasticity. This study evaluates the feasibility of hand therapy using a robotic hand orthosis (RELab tenoexo) with a mobile phone application as an adjunct to BoNT-A injections. Five chronic spastic patients participated in a two-session pilot study. Functional (Box and Block Test (BBT), Action Research Arm Test (ARAT)), and muscle tone (Modified Ashworth Scale (MAS)) assessments were conducted to assess functional abilities and impairment, along with usability evaluations. In the first session, subjects received BoNT-A injections, and then they performed a simulated unsupervised therapy session with the RELab tenoexo in a second session a month later. Results showed that BoNT-A reduced muscle tone (from 12.2 to 7.4 MAS points). The addition of RELab tenoexo therapy was safe, led to functional improvements in four subjects (two-cube increase in BBT as well as 2.8 points in grasp and 1.3 points in grip on ARAT). Usability results indicate that, with minor improvements, adjunct RELab tenoexo therapy could enhance therapy doses and, potentially, long-term outcomes. Full article

Due to limitations in current motion tracking technologies and increasing interest in alternative sensors for motion tracking both inside and outside the MRI system, in this study we share our preliminary experience with three alternative sensors utilizing diverse technologies and interactions with tissue to monitor motion of the body surface, respiratory-related motion of major organs, and non-respiratory motion of deep-seated organs. These consist of (1) a Pilot-Tone RF transmitter combined with deep learning algorithms for tracking liver motion, (2) a single-channel ultrasound transducer with deep learning for monitoring bladder motion, and (3) a 3D Time-of-Flight camera for observing the motion of the anterior torso surface. Additionally, we demonstrate the capability of these sensors to simultaneously capture motion data outside the MRI environment, which is particularly relevant for procedures like radiation therapy, where motion status could be related to previously characterized cyclical anatomical data. Our findings indicate that the ultrasound sensor can track motion in deep-seated organs (bladder) as well as respiratory-related motion. The Time-of-Flight camera offers ease of interpretation and performs well in detecting surface motion (respiration). The Pilot-Tone demonstrates efficacy in tracking bulk respiratory motion and motion of major organs (liver). Simultaneous use of all three sensors could provide complementary motion information outside the MRI bore, providing potential value for motion tracking during position-sensitive treatments such as radiation therapy. Full article

Backgound: Type 2 diabetes mellitus (T2DM) is a major cardiovascular risk factor. Nitric oxide (NO) is one of the many molecules that regulate vascular tone, and red blood cells (RBCs) are known to play an important role in adjusting cardiac function through NO export from RBCs. Our study prospectively investigated the L-arginine (L-arg)–nitric oxide (NO) metabolic pathway in the erythrocytes and plasma of subjects with T2DM. Methods: RBCs and plasma were collected from patients with T2DM (n = 10), at first clinical onset (baseline) and after five years of disease evolution (follow-up). L-arg content was assayed by competitive enzyme-linked immunoassay. Arginase activity and nitrate/nitrite levels were measured using spectrophotometry. Results: When compared to baseline, L-arg content decreased in RBCs and remained similar in the plasma; NO production decreased in RBCs and the plasma; and arginase activity was lower in RBCs and increased in plasma. Conclusions: The L-arg/NO metabolic pathway decreases in the RBCs of patients with T2DM five years after the first clinical onset. The persistent decrease in RBCs’ arginase activity fails to compensate for the sustained decrease in RBCs’ NO production in the diabetic environment. This pilot study indicates that the NO-RBC pool is depleted during the progression of the disease in the same cohort of T2DM patients. Full article

Background: The 1064 nm Q-switched neodymium-doped yttrium aluminum garnet (QS Nd:YAG) laser was developed to treat unwanted pigmentation in the skin such as lentigines caused by photoaging, and tattoos from dye/ink insertion. This laser has also been used for non-ablative epidermal rejuvenation (skin toning). Objective: To evaluate changes in skin tone, skin texture and overall improvement after a series of treatments with the QS Nd:YAG laser. Methods: Participants received seven full-face treatments with M22 or Stellar M22, a 1064 nm QS Nd:YAG laser, at 2-week intervals. The investigators and participants evaluated the improvement in skin tone and texture at 1, 3 and 6 months after the last treatment. Patient satisfaction, patient discomfort, downtime and adverse events were recorded. Histological changes in the treated area were also evaluated. Results: Thirteen women with a median age of 45 years (range, 34–61 years) were included in the study. The majority of the participants (53.9%) had skin type VI. One month after the last treatment session, 38% of participants reported good to very good improvement. This value increased to 100% participant improvement at both the 3-month and 6-month follow-up visits. The reduction in melanin index and the histological analysis demonstrated that the laser procedure contributed to a reduction in epidermal melanin content. Treatments were not associated with high levels of pain or discomfort. The most common immediate post-treatment response was erythema and edema. Most participants were satisfied with the resulting treatment outcome. Conclusion: Skin treatment with the 1064 nm QS Nd:YAG laser module on the M22 and Stellar M22 devices, using a large spot size, low fluence, moderately high repetition rate, improves skin tone and texture in patients with skin types II–VI. Full article

A digital subcarrier multiplexing (DSCM) system has been proposed as a possible solution for large capacity and long-distance coherent optical transmissions due to its high tolerances for chromatic dispersion (CD), equalization-enhanced phase noise (EEPN) and fiber nonlinearity. In a DSCM receiver, for subcarrier-demultiplex to occur properly, frequency offset estimation (FOE) must be implemented before demultiplexing. It is beneficial to decrease complexity and EEPN by compensating CD on each subcarrier. Therefore, a high CD tolerance is indispensable for the FOE algorithm in a DSCM receiver. However, the mainstream blind FOE algorithms for single-carrier systems, such as the 4th power fast Fourier transform algorithm, could not work for DSCM systems. To deal with this challenge, a pilot tone-based FOE algorithm with high CD tolerance is proposed and verified using simulations and offline experiments. The final estimation accuracy of about 10 MHz of the proposed two-stage FOE is achieved at low computational complexity. Simulations and offline experiments show that DSCM systems with the proposed algorithm have a 0.5~1 dB Q-factor improvement over Nyquist single-carrier systems. Full article

Dual-polarization division multiplexing (DPDM) is considered to be a potential method to boost the secure key rate (SKR) of the continuous-variable quantum key distribution (CV-QKD) system. In this article, we propose a pilot alternately assisted local local oscillator (LLO) CV-QKD scheme based on multi-dimensional multiplexing, where time division multiplexing and frequency division multiplexing are combined with dual-polarization multiplexing techniques to dramatically isolate the quantum signal from the pilot tone. We establish a general excess noise model for the LLO CV-QKD system to analyze the influence mechanism of various disturbances (e.g., time-domain diffusion, frequency-domain modulation residual, and polarization perturbation) on the key parameters, such as the channel transmittance and excess noise. Specifically, the photon leakage noise from the reference path to the quantum path and that between quantum signals with two different polarization paths are simultaneously analyzed in the dual-polarization LLO CV-QKD scheme for the first time. Furthermore, a series of simulations are established to verify the performance of the proposed scheme. The results show that the maximal isolation degree achieves 84.0 dB~90.4 dB, and the crosstalk between pilot tones and quantum signals can be suppressed to a very small range. By optimizing the system parameters (e.g., modulation variance and repetition frequency), the SKR with 12.801 Mbps@25 km is achieved under the infinite polarization extinction ratio (PER) and 30 dB residual ratio of the frequency modulation in the nanosecond-level pulse width. Moreover, the performance of the proposed DPDM CV-QKD scheme under relatively harsh conditions is simulated; the results show that the SKR with 1.02 Mbps@25 km is achieved under a relatively low PER of 17 dB with the nanosecond-level pulse width and 20 dB residual ratio of the frequency modulation. Our work lays an important theoretical foundation for the practical DPDM LLO CV-QKD system. Full article