The intelligent knee sleeve: A wearable biofeedback device

A unique textile-based device, the intelligent knee sleeve (IKS), uses conducting polymer technology to provide feedback on knee flexion angle for injury prevention programs. After identifying the most appropriate base fabric for the sensor, 12 athletes (age = 26.1 ± 3.2 years) performed four landing movements while wearing the sleeve, which was set to provide audible feedback at 25° and 45° knee flexion. Sensor and audible output (1000 Hz), knee kinematics (200 Hz) and ground reaction forces (1000 Hz) were recorded during the landing movements using an OPTOTRAK^® motion analysis system. Paired t-tests and intraclass correlation coefficients were used to determine validity and reliability of the feedback. The results revealed that the audible feedback tone was able to significantly differentiate between different goniometer-programmed knee angles (25° and 45°). Knee angles computed using the kinematic data from each trial for each movement were also highly reliable (intraclass correlation coefficients, R₁ = 0.903–0.988). It was concluded that although the IKS provides valid and reliable feedback on knee flexion angle, consistent feedback is dependent upon use of a sensor unaffected by environmental conditions. Such wearable biofeedback systems have application in a broad spectrum of activities, including performance enhancement, injury prevention and rehabilitation.     

探讨生物反馈对老年习惯性功能性便秘的临床疗效

目的评价生物反馈方法治疗功能性便秘的疗效。方法对我院171例习惯性功能性便秘患者进行生物反馈治疗,治疗前后进行临床评估、肛门直肠动力分析。结果经过生物反馈治疗后患者临床症状有了极大的改善。生物反馈治疗习惯性功能性便秘有效。     

脑电生物反馈仪的设计与实现

用脑电生物反馈治疗儿童注意力障碍多动综合症，是一种强有力的手段。本文设计了功能齐全、性能优良的脑电生物反馈系统，提出了系统硬件和软件的实现方案，并研制了该系统的样机，具有一定的临床应用价值。     

Unwind: a musical biofeedback for relaxation assistance

Unwind is a musical biofeedback interface which combines nature sounds and sedative music into a form of New-Age music for relaxation exercises. The nature sounds respond to the user’s physiological data, functioning as an informative layer for biofeedback display. The sedative music aims to induce calmness and evoke positive emotions. UnWind incorporates the benefits of biofeedback and sedative music to facilitate deep breathing, moderate arousal, and promote mental relaxation. We evaluated Unwind in a 2?×?2 factorial experiment with music and biofeedback as independent factors. Forty young adults performed the relaxation exercise under one of the following conditions after experiencing a stressful task: Nature sounds only (NS), Nature sounds with music (NM), and Auditory biofeedback with nature sounds (NSBFB), and UnWind musical biofeedback (NMBFB). The results revealed a significant interaction effect between music and biofeedback on the improvement of heart rate variability. The combination of music and nature sounds also showed benefits in lowering arousal and reducing self-report anxiety. We conclude with a discussion of UnWind for biofeedback and the wider potential of blending nature sounds with music as a musical interface.     

On the controllability assessment of biofeedback eyeglasses used in Presbyopia treatment

In recent years, hybrid biofeedback systems utilizing user-controlled electrically tunable lenses have emerged as potential treatments for presbyopia. However, the controllability of these systems, closely linked to user adaptability, has received limited attention in the literature due to the challenges associated with obtaining a comprehensive system model. In this study, we present the design, implementation, and validation of an innovative experimental setup aimed at researching and evaluating the controllability of such a biofeedback system. Our setup incorporates a novel low-complexity model, considering the brain, natural lenses (e.g., the crystalline lens), and electrically tunable lenses, to establish a fundamental model for hybrid biofeedback systems. This model is developed based on an analysis of biofeedback systems, geometrical optics, and control theory, facilitating the identification of strategies to decouple system dynamics and enable precise controllability analysis. The proposed experimental setup was validated with volunteers, providing evidence that confirms the reliable operation of the biofeedback system. Our approach encourages a shift from conventional qualitative approaches toward quantitative evaluation of biofeedback devices. The proposed model and experimental setup hold the potential to statistically assess the controllability of hybrid biofeedback systems for correcting presbyopia, paving the way for further advancements in this field.