人体运动力学分析方法的回顾与展望

运动力学作为生物力学重要的分支和前沿方向,近年来在运动数据获取、力学参数测量及人体动力学模型建立等方面取得了许多重大进展,并对运动损伤预防及康复医学等领域产生了重要的影响。人体内力环境是运动、负荷、生物学和形态学相互作用的结果,准确测量和估计人体内力环境是运动生物力学的研究重点和难点,而个性化的数据获取和模型建立也是获得物理与生理上有效的组织生物力学预测的关键。该文回顾了运动学和动力学的研究与发展,为运动力学分析方法提供系统与全面的工作框架,并展望学科未来的应用与发展趋势,为相关领域的研究者提供参考。     

植入式医疗器械的应用及耐久性

天然人体部分的损伤及功能丧失后的器械置换,可追溯到远古的埃及。植入式医疗器械的最早形式是假体。第一个心脏起搏器发明于五十年代,第一个人工心脏瓣膜1952年植入于人体,第一个人工髋关节置换于1954年获得成功。在这30余年的实践中,专家们一直密切关注着一些广泛应用的植入物的长期有效性和安全性。美国健康统计中心(NCHS)已经统计了人工关节、固定器械、起搏器、人工心脏瓣膜、耳通气管、眼内棱镜、硅植入物、导管、分流器、齿科植入物和其他一些类型的医疗器械,如人工血管、韧带、尿道括约肌和灌注泵等植入数量。NCHS和FDA预言,约有1100万的美国人(占总数的4.6%)至少要用上一次植入性医疗器械。其中,约     

微型植入式医疗电子设备的信号传导机制

微型植入式医疗电子设备是一种长时间埋于人体,用于监测生理特征的微型医疗器械。为了研究微型植入式医疗电子设备如何利用电信号实现植入物与体表检测设备的通信,并分析信号传导机制,本研究利用数学建模的方法,通过设定合理的边界条件和假设,建立微型植入式医疗电子设备体导通信信道模型。为了验证体导通信信道模型的解的准确性,建立了等效的数值解模型,通过分析体导通信信道模型和数值解模型的结果,发现两种模型的误差小于1%。为了验证体导通信信道模型与实验结果的一致性,选用文献中的实验数据来进行验证,通过对比实验结果与体导通信信道模型计算结果,发现体导通信信道模型的解和实验结果误差小于4 dB,具有良好的一致性。因此,体导通信信道模型的解是准确的,体导通信信道模型与实验也有较好的一致性。     

虚拟人体的研究现状与进展

综述了目前国际上有关虚拟人体在多个层面上的研究现状.首先以心脏虚拟模型为例,介绍了从细胞到器官功能系统的虚拟模型建立方法和研究现状,然后简要介绍了整个虚拟人体计划的研究进展和相关的标准、工具以及数据库的发展状况,讨论了虚拟人体在医疗诊断、医疗器械设计、虚拟手术及医学教育与训练等方面的应用.最后总结了目前虚拟人体研究领域所面临的挑战,并对其军事应用意义进行了探讨.     

基于关节坐标系的肌肉骨骼间附着点坐标转换方法

目的运动状态下对人体骨肌系统进行运动学及动力学分析时,应避免对人体造成伤害。本研究通过尸体切片、CT或者MRI图像重建等方法构建静态骨肌模型,并将其应用于活体进行分析。方法采用尸体切片数据重建下肢的三维骨肌模型,并对此骨肌模型及活体下肢建立统一规则的关节坐标系,详细描述人体骨肌系统模型和活体上相关肌肉骨骼间附着点空间坐标值转换。结果对研究对象膝关节屈曲运动中股二头肌短头力臂及长度进行计算和分析。结论该方法对提高人体运动学和动力学仿真及肌肉力预测具有重要意义。     

人体下肢多体动力学仿真和步态稳定性实验研究

人体下肢是人进行步行运动的主要工具,下肢的肌肉骨骼系统是步行的执行机构,正常的下肢功能保证了人们的日常活动;下肢损伤会引起人们运动障碍,下肢运动障碍康复者虽然具有行走的能力,但是其稳定性和平衡性较差。本文着眼于人体下肢,总结并阐述了人体下肢多体动力学仿真以及步态稳定性的实验研究进展,展望了其发展趋势,旨在为临床康复治疗及康复设备的设计与开发提供帮助与数据支持。     

生物医用钛合金材料的生物及力学相容性

背景：保证生物材料优良的生物及力学相容性是研制开发外科植入物及矫形器械产品的关键,但目前对其研究缺乏系统性和统一性认识。 目的：初步分析生物医用钛合金材料生物及力学相容性的概念、内涵,指导医疗器械产品的选型设计与应用。 方法：应用计算机检索PubMed、Elsiver、Springerlink、CNKI及维普等数据库1995至2012年相关文献,围绕“生物及力学相容性”主题词,探讨合金成分、显微组织及相变控制和材料表面状态优化等因素对钛合金材料生物及力学相容性的影响规律。 结果与结论：生物及力学相容性是一个综合评价概念。进行医用钛合金材料选型设计时,首先要求合金中的组成元素无不良反应,并保证其与组织、血液及免疫和全身反应的安全性,同时要求所添加元素对钛合金的机械性能等其他性能不良影响最小。钛合金中常见的合金化元素主要包括α相稳定元素、β相稳定元素和中性元素3类。要使生物医用钛合金植入材料获得优良的生物及力学相容性,对材料内部显微组织和相变进行控制,以及开展材料表面状态改性优化也至关重要。但不能单纯追求一种钛合金的低模量或高强度等某一单项力学指标与人体骨组织接近或匹配而简单判定其生物力学相容性的优劣。     

基于AnyBody~(TM)技术的人体运动建模方法

人体运动的建模与仿真是当今运动生物力学研究的一个热点。利用数值模型研究人体的运动规律,是人体运动研究的一个重要手段和有效工具。其关键技术在于应用逆向运动学方法求解人体运动,并获取人体运动中各个肌肉力学上技术参数。文中主要探讨基于AnyBody~(TM) System软件人体运动仿真的建模方法来研究人体运动力学规律,结合The Any-Body~(TM)system对人体运动具体应用,说明The AnyBody~(TM) system技术在人体运动仿真领域的优势。     

植入式人工肛门括约肌系统的实现及动物实验***

背景：研制新型的符合人体生理需求的人工肛门括约肌系统具有十分重要的意义。 目的：设计一种新型植入式人工肛门括约肌系统。 方法：利用无线通讯模块和压力传感器重建排便控制机制,并由经皮能量传输模块供电,采用机电系统模拟人体自然器官的功能,最终实现人体肛门括约肌的控制效果。 结果与结论：设计并实现了一种新型的植入式人工肛门括约肌系统,在重建排便机制和模型的基础上,一定程度上恢复肛门失禁患者的生物反馈控制能力,并带有经皮能量传输模块,为体内系统长期无缆式供电提供可能。该系统实现了植入式动物实验,完成了系统植入可行性和基本功能验证。 关键词：人工肛门括约肌;生物反馈控制;经皮能量传输;植入式动物实验;数字化医学  doi:10.3969/j.issn.1673-8225.2012.13.013     

开展医疗器械安全工程学研究防止不良事件发生

主要介绍了医疗器械安全工程学.近年来日本、欧美等发达国家积极开展这个学科的研究,以减少不良事件的发生.除一般的安全问题外,医疗器械安全工程学研究的主要内容包括人因工程、人体工程学、医用软件、人机接口及误使用等.     

Security and privacy issues in implantable medical devices: A comprehensive survey

Bioengineering is a field in expansion. New technologies are appearing to provide a more efficient treatment of diseases or human deficiencies. Implantable Medical Devices (IMDs) constitute one example, these being devices with more computing, decision making and communication capabilities. Several research works in the computer security field have identified serious security and privacy risks in IMDs that could compromise the implant and even the health of the patient who carries it. This article surveys the main security goals for the next generation of IMDs and analyzes the most relevant protection mechanisms proposed so far. On the one hand, the security proposals must have into consideration the inherent constraints of these small and implanted devices: energy, storage and computing power. On the other hand, proposed solutions must achieve an adequate balance between the safety of the patient and the security level offered, with the battery lifetime being another critical parameter in the design phase.     

Impact of a training program on adherence to recommendations for care of venous lines in internal medicine departments in Spain

A high percentage of venous lines (VLs) are placed in non-ICU patients, particularly those treated in the internal medicine department (IMD). We assessed adherence to VL care after a training program aimed at nurses and clinicians attending patients admitted to Spanish IMDs. We performed a multicenter prospective observational point prevalence study in 14 Spanish IMDs in 2013 and 2016. We included all adult patients (>?18 years) admitted to IMDs on the study day and reviewed nursing records for patients with VL in place before and after a 1-year training program during 2015. Answers from an interview with head nurses of the IMDs regarding commonly used practices in the daily management of VLs were also compared. A total of 638 and 693 patients were seen during each period, respectively, and 530 and 598 patients had ≥?1 VL implanted (83.1 vs. 86.3%). Catheters were considered unnecessary in 12.8 and 15.0% of cases (p?=?0.28). Daily recording of the need for catheter use increased from 43.8 to 71.8% (p?<?0.001). Furthermore, daily monitoring of the insertion site remained very frequent (94.4 vs. 92.2%; p?=?0.16). The date of insertion was recorded in 86.3 and 85.5% of cases (p?=?0.73), and no combination of closed connectors with open caps increased from 74.8 to 90.3% (p?<?0.001). Overall, head nurses’ knowledge improved in 4 out of 14 recommendations assessed (28.6%). A simple and easy program for training on management of VLs in Spanish IMDs was associated with improved quality of care.     

The current state of adult metabolic medicine in the United States: Results of a nationwide survey

PurposePatients with inherited metabolic disorders (IMDs) now have improved health outcomes and increased survival into adulthood. There is scant evidence on managing adults with IMDs. We present an analysis of current care practices for adults with IMDs in the United States.MethodsWe created and distributed an online survey to US members of the Society of Inherited Metabolic Disorders. The survey addressed ambulatory care, acute management, and health care transition (HCT) practices of adults with IMDs.ResultsThe survey was completed by 91 providers from 73 institutions. Most adult patients with IMDs receive lifelong care from a single metabolic clinician, predominantly in pediatric clinic settings. Adults receive comprehensive ambulatory metabolic care, but fewer trainees participate compared with pediatric visits. Most acute IMD management occurs in pediatric hospitals. Clinician comfort with HCT increased the frequency of HCT planning. Overall, all respondents felt that providing specialized care to adults with IMDs is high value.ConclusionOur survey demonstrates the paucity of clinical resources dedicated to adult metabolic medicine. Care is fragmented and varies by medical system. Interest in HCT is robust but would benefit from standardized practices. Our findings reinforce the need for greater focus on adult metabolic medicine in the United States.     

A new hermetic antenna for wireless transmission systems of implantable medical devices

In implantable medical devices (IMDs), the need of telemetry systems able to provide wireless bidirectional communication to interrogate and remotely program the device, as well as to monitor the physiological status of the patient, is growing. The object of the present study was to evaluate a new hermetic antenna for wireless short-range transmission system for IMDs which would assure reliable long-term functioning due to the high level of hermeticity of antenna's housing that limits the influence of body tissue environment on transmitted signals. Experimental tests were conducted on three different prototypes to evaluate the most efficient antenna configuration for transmission both in the air and through a mixture simulating the human thorax. Further tests were performed to assess the influence of electro-catheters connected to IMDs on transmitted signals. Results showed that the hermetic antenna guarantees a good wireless transmission both in the air and through the human thorax simulator. The results also show that the presence of an electro-catheter can influence the effective radiated power (ERP) transmitted depending on its position in relation to the telemetric circuitry. Both a controlled increase of the ERP without exceeding the limits imposed by rules and the optimization of the tuning between the antenna and the transmitter can assure a reliable short-range transmission (several meters) using the new hermetic antenna proposed.     

Design and validation of a metabolic disorder resequencing microarray (BRUM1)

The molecular genetic diagnosis of inherited metabolic disorders is challenging. The diseases are rare, and most show locus heterogeneity. Hence, testing of the genes associated with IMDs is time consuming and often not easily available. We report a resequencing array that allows the simultaneous resequencing of up to 92 genes associated with IMDs. To validate the array, DNA samples from 51 patients with 52 different known variants (including point variants, small insertion, and deletions [indels]) in seven genes (C14ORF133, GAA, NPC1, NPC2, VPS33B, WFS1, and SLC19A2) were amplified by PCR and hybridized to the array. A further patient cohort with 48 different mutations in NPC1 were analyzed blind. Out of 76 point variants, 73 were identified using automated software analysis followed by manual review. Ten insertion and deletion variants were detected in the extra tiling using mutation specific probes, with 11 heterozygous deletions and 3 heterozygous insertions. In summary, we identified 96% (95% confidence interval [CI] 89–99%) of point variants added to the array, but the pickup rate reduced to 83% (95% CI 75–89%) when insertions/deletions were included. Although the methodology has strengths and weaknesses, application of this technique could expedite diagnosis in most patients with multilocus IMDs. Hum Mutat 31:1–8, 2010. © 2010 Wiley‐Liss, Inc.     

Reduced-Toxicity (BuFlu) Conditioning Is Better Tolerated but Has a Higher Second Transplantation Rate Compared to Myeloablative Conditioning (BuCy) in Children with Inherited Metabolic Disorders

Hematopoietic stem cell transplantation (HCT) is a primary treatment for various inherited metabolic disorders (IMDs). Achieving stable and sustained engraftment while minimizing transplantation-related morbidity and mortality is critical to optimizing outcomes for IMDs. Traditional regimens have used myeloablative approaches, primarily busulfan and cyclophosphamide (BuCy), which is associated with significant regimen-related toxicity. Alternatively, reduced-toxicity regimens, such as busulfan and fludarabine (BuFlu), have been proposed to offer similar efficacy with reduced toxicities. We compared transplantation-related outcomes with BuCy-based and BuFlu-based conditioning in patients with IMDs. We retrospectively analyzed the University of Minnesota's transplantation database for patients with IMDs who underwent HCT using a BuCy (with alemtuzumab) or BuFlu (with antithymocyte globulin) preparative regimen between March 2008 and September 2017. Overall survival (OS), event-free survival (EFS), and incidence of neutrophil and platelet recovery were determined using standard definitions. Complications such as graft failure, sinusoidal obstruction syndrome, hemorrhagic cystitis, and respiratory failure were compared. Graft failure includes primary and secondary aplastic graft failure with and without autologous recovery. The incidence of viral infections post-transplantation in the 2 regimens was also determined. A total of 99 patients underwent HCT for IMDs during the study period. Sixty-four patients received BuCy conditioning, and the other 35 received BuFlu. Hurler syndrome (46%) and adrenoleukodystrophy (43%) were the most common IMDs, and umbilical cord blood was the most common graft source (74%). One-year OS was similar in the 2 groups (81.2% in BuCy versus 85.5% in BuFlu; P = .8), with an EFS of 75% versus 63%, respectively. The 2 groups also had similar incidences of grade III-IV acute GVHD (9% versus 6%; P = .5) and chronic GVHD (9% versus 7%; P = .67). Neutrophil and platelet recovery were similar in the 2 groups, with a significantly shorter duration of hospital stay noted in the BuFlu cohort (median, 21 days versus 34 days; P = .002). The cumulative incidence of graft failure was significantly higher in the BuFlu group (29% versus 14%; P = .08), as was the rate of second HCT (27% versus 3%; P = .001). The incidences of adenoviral infection (14% versus 0%; P = .02) and hemorrhagic cystitis (23% versus 3%; P = .01) were higher in the BuCy group. T cell engraftment occurred significantly sooner with BuCy conditioning until 1-year post-transplantation, but donor myeloid engraftment was similar in the 2 groups. Our data indicate that reduced-toxicity conditioning is associated with lower rates of infection and other transplantation-related complications but is concerning for a higher rate of graft failure in patients with IMDs. Alternate immunosuppressive agents and novel techniques should be considered to minimize toxicities and reduce complications.     

Effects of daily activities and social behavior on blood-pressure elevation

This study examined the effects of daily activities and social behavior on the blood-pressure elevation in 21 normotensives, 20 borderline hypertensives, and 20 sustained essential hypertensives. Blood pressures were recorded over a 24-hr period using an ambulatory monitor while subjects recorded their daily activities and social involvement at each cuff inflation. Results indicated that only a moderate proportion of the blood pressure readings of the two clinical groups exceeded 140/90 mm Hg. Results also suggested that the blood pressures of normotensives were more responsive to changes in physical activity, while the blood pressures of sustained hypertensives were more responsive to social involvement. When group differences emerged on mean blood-pressure elevation, analyses indicated that the two hypertensive groups frequently differed from the normotensive group but rarely from each other. The results suggest that differences in blood-pressure elevation cannot be fully understood without considering behavior and support its continued inclusion in the study of blood pressure.This research was supported in part by National Institutes of Health Grant HL 29795 to Janis H. Crowther and Mary Ann P. Stephens.     

Physical work capacity and daily physical activities of handicapped and non-handicapped children

Summary In this study physical work capacity, mechanical efficiency on the bicycle ergometer and daily physical activities were compared between 24 physically handicapped and 24 non-handicapped children. As a measure of mechanical efficiency and physical work capacity, the oxygen uptake per kg body weight at 0.5 watt·kg^–1 and oxygen uptake per kg body weight at a heart rate of 150 beats·min^–1 were used. The daily physical activities were recorded during a 24-h period by means of a scoring list. The load imposed by the daily physical activities was investigated by registration of heart rate.The mean value of the physical work capacity of the group of handicapped children was found to be lower compared with the non-handicapped children. The mechanical efficiency of 7 of the 24 handicapped children was lower when compared with the mechanical efficiency of 23 of the 24 non-handicapped children. A significant correlation between mechanical efficiency and nature of the handicap (spastic hemi-, di-, tetraplegic) was found (p<0.05). During light daily physical activities the handicapped children showed the same mean heart rate as the non-handicapped children, but the mean heart rate during heavy daily physical activities was lower for the handicapped group than for the non-handicapped group. The non-handicapped children spent more time in physical activities with relatively high heart rates.From the results obtained of oxygen uptake and heart rate measurements it is to be expected that non-handicapped children are able to maintain a higher state of training by means of their daily physical activities than are handicapped children.     

Neuropsychological findings in young-adult stroke patients.

There are few data on neuropsychological deficits in young-adult stroke patients. This study investigates cognitive conditions in a young-adult stroke population, as well as tasks that detect their neuropsychological impairment. Forty 18- to 47-year-old stroke patients, and a matched control group, completed a neuropsychological battery to evaluate deficits related to cognition, daily activities and mood. Patients performed worse than controls; five patients were classified as demented, three had global cognitive impairment and eight partial cognitive impairment. Cognitive impairment was more closely associated with reduced performance of daily activities than with motor deficits.     

Pneumonia treated in the internal medicine department: focus on healthcare-associated pneumonia

Patients with pneumonia treated in the internal medicine department (IMD) are often at risk of healthcare-associated pneumonia (HCAP). The importance of HCAP is controversial. We invited physicians from 72 IMDs to report on all patients with pneumonia hospitalized in their department during 2 weeks (one each in January and June 2010) to compare HCAP with community-acquired pneumonia (CAP) and hospital-acquired pneumonia (HAP). We analysed 1002 episodes of pneumonia: 58.9% were CAP, 30.6% were HCAP and 10.4% were HAP. A comparison between CAP, HCAP and HAP showed that HCAP patients were older (77, 83 and 80.5 years; p < 0.001), had poorer functional status (Barthel 100, 30 and 65; p < 0.001) and had more risk factors for aspiration pneumonia (18, 50 and 34%; p < 0.001). The frequency of testing to establish an aetiological diagnosis was lower among HCAP patients (87, 72 and 79; p < 0.001), as was adherence to the therapeutic recommendations of guidelines (70, 23 and 56%; p < 0.001). In-hospital mortality increased progressively between CAP, HCAP and HAP (8, 19 and 27%; p < 0.001). Streptococcus pneumoniae was the main pathogen in CAP and HCAP. Pseudomonas aeruginosa and methicillin-resistant Staphylococcus aureus (MRSA) caused 17 and 12.3% of HCAP. In patients with a confirmed aetiological diagnosis, the independent risk factors for pneumonia due do difficult-to-treat microorganisms (Enterobacteriaceae, P. aeruginosa or MRSA) were HCAP, chronic obstructive pulmonary diseases and higher Port Severity Index. Our data confirm the importance of maintaining high awareness of HCAP among patients treated in IMDs, because of the different aetiologies, therapy requirements and prognosis of this population.