“量化自我”潮流中的技术与身体之同构关系研究——以运动应用程序Keep为例

本文聚焦于诉诸于量化自我的运动应用程序,以Keep这一具有代表性的软件为例,立足于自我跟踪用户与自我、与系统、与社交网络这三个相互关联的维度上的交互,解读用户身体与追踪技术之间的同构关系。本文指出,以个性化、定制化健身为卖点的此类运动应用程序,实质奉行着一套统一的、排除差异的量化标杆,在此基础上传递出推崇瘦形象、批判胖形象的运动理念。基于这种二元对立的思路,用户采用自我监控并寻求他者凝视以规避不自律、不健康、不正常的负面评价,这一过程中,数字健康技术与身体保持着相互的反馈性,以瘦为美的身材标准作为既有意识形态框定了反馈循环的发展,这意味着技术不仅记录身体过去的运动历史,并决定现在的运动章程,更书写、影响着未来的运动目标。而人类借助技术来认识身体、认识自我的这份追求背后,映射出消费主义浪潮关于健康与审美话语的不容忽视的影响力。

Effects of multidisciplinary exercise management on patients after percutaneous coronary intervention:A randomized controlled study

Objectives To explore the effectiveness of the mobile app-based multidisciplinary exercise management on patients who receive percutaneous coronary intervention(PCI).Methods From January to October 2020,54 patients after PCI were randomly assigned to the intervention group(n=27)and the control group(n=27).The intervention group received the mobile app-based multidisciplinary exercise management,whereas the control group received routine care.The patients after PCI began to take intervention one month after the operation,and the intervention lasted for two months.Before and after the intervention,6-Minute Walking Distance was used to evaluate the patient’s exercise tolerance,and the patient’s exercise compliance was evaluated according to the patient’s exercise status recorded by the mobile app.The cognitive questionnaire on knowledge about PCI treatment for Coronary Heart Disease,the Self-efficacy for Chronic Disease Scale and the Perceived Social Support Scale were used to evaluate patients’disease-related cognition,self-efficacy and perception of social support.This study was registered on Clinical Trials.gov with registration number ChiCTR2000028930.Results Totally 51 patients after PCI who completed this study(25 patients in the intervention group and 26 patients in the control group)were included in the analysis.After 2 months of intervention,the exercise compliance of patients in the intervention group was better than that in the control group.And 6-Minute Walking Distance(469.36±57.48 vs.432.81±67.09),and the scores of knowledge of PCI treatment for coronary heart disease(52.64±9.82 vs.42.42±8.54),Self-efficacy for Chronic Disease Scale(42.40±8.04 vs.36.88±7.73)and Perceived Social Support Scale(74.04±5.73 vs.66.69±6.86)in the intervention group were higher than those in the control group with statistical significance(P<0.05).Conclusions The multidisciplinary exercise management based on the mobile app can effectively improve exercise tolerance,exercise compliance,disease-related cognition,self-efficacy,and perception of social support during exercise training for patients after PCI.

Healthcare Algorithms by Wearable Inertial Sensors: A Survey

Wearable smart devices, such as smart watch, wristband are becoming increasingly popular recently. They generally integrate the MEMS-designed inertial sensors, including accelerometer, gyroscope and compass, which provide a convenient and inexpensive way to collect motion data of users. Such rich, continuous motion data provide great potential for remote healthcare and decease diagnosis. Information processing algorithms play the critical role in these approaches, which is to extract the motion signatures and to access different kinds of judgements. This paper reviews key algorithms in these areas. In particular, we focus on three kinds of applications: 1) gait analysis; 2) fall detection and 3) sleep monitoring. They are the most popular healthcare applications based on the inertial data. By categorizing and introducing the key algorithms, this paper tries to build a clear map of how the inertial data are processed; how the inertial signatures are defined, extracted, and utilized in different kinds of applications. This will provide a valuable guidance for users to understand the methodologies and to select proper algorithm for specifi c application purpose.

Influence of the Number of Rollers on a Tapered Roller Bearing

In roller bearings, the outer ring is usually fixed and the inner ring has the rolling motion. Concerning TRB （tapered roller bearings）, this motion generates forces that are transmitted to the outer ring by the tapered rollers. Thus, contact stresses occur and the number of rollers plays a major role with respect to the load distribution. This influence is analyzed in this study by the FEM （finite element method） with commercial code ABAQUS, where two models were evaluated： a common TRB and the same one but with fewer rollers. As an application, a manual automotive transmission was considered for the input loads.

Artificial molecular machines that can perform work

An artificial molecular machine consists of molecule or substituent components jointed together in a specific way so that their mutual displacements could be initiated using appropriate outside stimuli. Such an ability of performing mechanical motions by consuming external energy has endowed these tiny machines with vast fascinating potential applications in areas such as actuators, manipulating atoms/molecules, drug delivery, molecular electronic devices, etc. To date, although vast kinds of molecular machine archetypes have been synthesized in facile ways, they are inclined to be defined as switches but not true machines in most cases because no useful work has been done during a working cycle. More efforts need to be devoted on the utilization and amplification of the nanoscale mechanical motions among synthetic molecular machines to accomplish useful tasks. Here we highlight some of the recent advances relating to molecular machines that can perform work on different length scales, ranging from microscopic levels to macroscopic ones.

Analytical geometry method of planetary gear trains

This paper presents an analytical geometry method for kinematics and efficiency of planetary gear trains (PGTs). The novel method which is capable of evolution and contrast analysis of mechanism kinematics, can be applied to any typical one-and two-degree-of-freedom plane PGTs containing any number of simple, compound or complex-compound planetary gear sets. The efficiency analysis of this method features a systematized and programmed process and its independence of the speed ratio. The primary contribution of this work lies in the integration of quantitative calculation, qualitative evolution and comparative analysis of kinematics of PGTs into one diagram, and in the integration of kinematics and efficiency analysis into a single method system. First, the analytical geometry method is defined, its basic properties are given, and the systematization procedure to perform kinematic analysis is demonstrated. As an application, analytical geometry diagrams of common PGTs are exhibited in the form of a list, whose kinematic characteristics and general evolution tendency are discussed. Then, with the mapping of PGTs onto the angular speed plane, the efficiency formula of analytical geometry, which has an extremely concise form, and a simple method for power flow estimation are put forward. Moreover, a general procedure is provided to analyze the efficiency and power flow. Finally, four numerical examples including a complicated eleven-link differential PGTs are given to illustrate the simpleness and intuitiveness of the analytical geometry method.