Hierarchical,Multi-Sensor Based Classification of Daily Life Activities: Comparison with State-of-the-Art Algorithms Using a Benchmark Dataset

Insufficient physical activity is the 4th leading risk factor for mortality. Methods for assessing the individual daily life activity (DLA) are of major interest in order to monitor the current health status and to provide feedback about the individual quality of life. The conventional assessment of DLAs with self-reports induces problems like reliability, validity, and sensitivity. The assessment of DLAs with small and light-weight wearable sensors (e.g. inertial measurement units) provides a reliable and objective method. State-of-the-art human physical activity classification systems differ in e.g. the number and kind of sensors, the performed activities, and the sampling rate. Hence, it is difficult to compare newly proposed classification algorithms to existing approaches in literature and no commonly used dataset exists. We generated a publicly available benchmark dataset for the classification of DLAs. Inertial data were recorded with four sensor nodes, each consisting of a triaxial accelerometer and a triaxial gyroscope, placed on wrist, hip, chest, and ankle. Further, we developed a novel, hierarchical, multi-sensor based classification system for the distinction of a large set of DLAs. Our hierarchical classification system reached an overall mean classification rate of 89.6% and was diligently compared to existing state-of-the-art algorithms using our benchmark dataset. For future research, the dataset can be used in the evaluation process of new classification algorithms and could speed up the process of getting the best performing and most appropriate DLA classification system.     

Current status of the development of wireless sensors for medical applications]

Wireless near-field transmission has been a challenge for scientists developing medical sensors for a long time. Here, instruments which measure a patient's ECG, oxygen saturation, blood pressure, peak flow, weight, blood glucose etc. are to be equipped with suitable transmission technology. Application scenarios for these sensors can be found in all medical areas where cable connections are irritating for the doctor, patient and other care personnel. This problem is especially common in sport medicine, sleep medicine, emergency medicine and intensive care. Based on its beneficial properties with regard to power consumption, range, data security and network capability, the worldwide standard radio technology Bluetooth was selected to transmit measurements. Since digital data is sent to a receiving station via Bluetooth, the measurement pre-processing now takes place in the patient sensor itself, instead of being processed by the monitor. In this article, a Bluetooth ECG, Bluetooth pulse oximeter, Bluetooth peak flow meter and Bluetooth event recorder will be introduced. On the one hand, systems can be realized with these devices, which allow patients to be monitored online (ECG, pulse oximeter). These devices can also be integrated in disease management programs (peak flow meter) and can be used to monitor high-risk patients in their home environment (event recorder).     

A Multidimensional Data Acquisition as a Preliminary Step to the Secondary Prevention of the Loss of Autonomy for Patients with Traumatic Injury and Stroke: An AMISIA Pilot Study

BackgroundThe aim of our study was to conduct an ad hoc data collection in healthy adults with the intention of extracting individual profiles to study the ability to effectively monitor one's health by extracting relevant indicators. As “each patient is a unique case”, AMISIA (Defi CNRS AUTON project) proposes an integrated approach, combining medical health devices, information technology, and human factors to provide patients, health care actors and family caregivers with both the best incentives and a high degree of monitoring.MethodWe conducted a data collection experiment in Limoges with 61 participants at the Limoges University. Data were biographic elements, socio-economic profiles, cognitive performance (Corsi test results), a psychological battery (anxiety, fatigue, sleep), posture and gait measurement with 4 Imus and a Wii-balance board, and finally physical activity during a week at home (Armband sensors).ResultsFor the Corsi virtual walking test, the median memory span for Group A was significantly less (p<0.001) than for Group B. Step count and active energy expenditure were significantly higher in Group B (p<0.05). A multiple regression analysis showed that gender, active energy expenditure, fatigue and tendency to play video games account for 41% of the memory span variance.ConclusionWe have shown that encouraging physical activity can be based on the knowledge of many parameters, such as weight, age, gender and other bio-psycho-social parameters that must also be included in the model.     

Use of A Continuous Glucose Monitor in the Management of Inoperable Meta Static Insulinoma: A Case Report

ObjectiveTo describe the successful use of a continuous glucose monitor in the management of a patient with inoperable metastatic insulinoma.MethodsWe present a case of inoperable recurrent metastatic insulinoma in which medical therapy failed to relieve symptoms of dangerous hypoglycemia. We describe how the use of a continuous glucose monitor has assisted in avoiding hypoglycemia and improving her quality of life.ResultsA 70-year-old woman with a history of recurrent surgically treated insulinoma presented with recurrent hypoglycemia secondary to multiple metastases in the liver. Diazoxide therapy decreased the frequency of symptoms, but she continued to have hypoglycemic episodes resulting in frequent visits to the emergency department. Since starting to use a continuous glucose monitor, she has been able to avoid hypoglycemia with associated neuroglycopenic symptoms. While the accuracy of the device was poor when compared with conventional fingerstick monitors, the sensor tended to read higher than the meter in the hypoglycemic range. Although this led to more frequent false-positive hypoglycemic alarms, true episodes of severe hypoglycemia were rare.ConclusionsMalignant insulinomas are rare tumors. Many affected patients have disease that is unresectable, and medical therapy is limited in its ability to prevent hypoglycemic episodes. We have demonstrated that a continuous glucose monitor can be a useful adjunct to therapy to reduce hypoglycemic episodes by alerting the patient to low glucose concentrations before the development of neuroglycopenic symptoms. (Endocr Pract. 2008;14:880-883)     

Evolution of emergency cardiac care in Canada.

Acute myocardial infarction is the most common cause of death in Canada. Most deaths occur within the first 2 hours of the onset of symptoms, before the person seeks or is able to obtain medical aid, and are due to arrhythmias rather than massive myocardial damage. Effective electrical and drug treatment of arrhythmias has reduced the hospital mortality but not the community mortality. If mortality from acute myocardial infarction and other causes of sudden unexpected death is to be reduced substantially a major reorganization of emergency medical services is needed so that the benefits of the modern coronary care unit can be provided to the patient as rapidly as possible. Public education in basic life support procedures to sustain life until advanced life support aid arrives is the first step towards the development of a more effective system of emergency cardiac care.     

Measuring clinically relevant knee motion with a self-calibrated wearable sensor

Low-cost sensors provide a unique opportunity to continuously monitor patient progress during rehabilitation; however, these sensors have yet to demonstrate the fidelity and lack the calibration paradigms necessary to be viable tools for clinical research. The purpose of this study was to validate a low-cost wearable sensor that accurately measured peak knee extension during clinical exercises and needed no additional equipment for calibration. Sagittal plane knee motion was quantified using a 9-axis motion sensor and directly compared to motion capture data. The motion sensor measured the field strength of a strong earth magnet secured to the distal femur, which was correlated with knee angle during a simple calibration process. Peak knee motions and kinematic patterns were compared with motion capture data using paired t-tests and cross correlation, respectively. Peak extension values during seated knee extensions were accurate within 5 degrees across all subjects (root mean square error: 2.6 degrees, P = 0.29). Knee flexion during gait strongly correlated (0.84 ≤ r_xy ≤ 0.99) with motion capture measurements but demonstrated peak flexion errors of 10 degrees. In this study, we present a low-cost sensor (≈$ 35 US) that accurately determines knee extension angle following a calibration procedure that did not require any other equipment. Our findings demonstrate that this sensor paradigm is a feasible tool to monitor patient progress throughout physical therapy. However, dynamic motions that are associated with soft-tissue artifact may limit the accuracy of this type of wearable sensor.     

The fate of young individuals with a history of myocardial infarction]

The fate of young individuals (to 45 years) with a history of myocardial infarction during 12 years was analysed with the aid of a questionnaire containing questions of both social and medical character. Sudden cardiac death or the second infarction were the most frequent causes of death during the first two years following myocardial infarction. Change in the physical activity mainly involved the return to work. Only 47% of young men and 29.8% of women started full-time jobs. They mainly belonged to so-called white collars. The lack of patients' physicians permission was a main cause of the abstinence of young men from the occupation. A position within the family and social activity usually remained unchanged in the majority of patients, but every third patient greatly reduced sexual activity. Every third patients continued smoking, and did not observe recommended diet despite the systematical medical check-ups. The course of the disease is unclear in the majority of young patients. It is often deformed and requires further, detailed information on young patients' style of life.     

Predictors for Half-Year Outcome of Impairment in Daily Life for Back Pain Patients Referred for Physiotherapy: A Prospective Observational Study

Background and Objective

From observational studies, there is only sparse information available on the predictors of development of impairment in daily life for patients receiving physiotherapy. Therefore, our aim was to identify factors which predict impairment in daily life for patients with back pain 6 months after receiving physiotherapy.

Methods

We conducted a prospective cohort study with 6-month follow-up. Patients were enrolled for treatment in private physiotherapy practices. Patients with a first physiotherapy referral because of thoracic or low back pain, aged 18 to 65 years were included. Primary outcome impairment was measured utilising the 16-item version of the Musculoskeletal Function Assessment Questionnaire. Therapy was documented on a standardized form. Baseline scores for impairment in daily life, symptom characteristics, sociodemographic and psychosocial factors, physical activity, nicotine consumption, intake of analgesics, comorbidity and delivered primary therapy approach were investigated as possible predictors. Univariate and multiple linear regression analyses were performed.

Results

A total of 792 patients participated in the study (59% female, mean age 44.4 (SD 11.4), with 6-month follow-up results available from 391 patients. In univariate analysis 17 variables reached significance. In multiple linear regression identified predictors were: impairment in daily life before therapy, mental disorders, duration of the complaints, self-prognosis on work ability, rheumatoid arthritis, age, form of stress at work and physical activity. The variables explain 34% of variance (adjusted R², p<0.001).

Conclusions

With minimal information available from observational studies on the predictors of development of back problems for physiotherapy patients, this study adds new knowledge for forming appropriate referral guidelines. Impairment in daily life before therapy, mental disorder as comorbidity and the duration of the complaints can be named as outstanding factors. The results of this study can be used to facilitate comparison of patient therapy goals with the prognosis in everyday practice.     

Upper limb joint angle measurement in occupational health

Usual human motion capture systems are designed to work in controlled laboratory conditions. For occupational health, instruments that can measure during normal daily life are essential, as the evaluation of the workers' movements is a key factor to reduce employee injury- and illness-related costs. In this paper, we present a method for joint angle measurement, combining inertial sensors (accelerometers and gyroscopes) and magnetic sensors. This method estimates wrist flexion, wrist lateral deviation, elbow flexion, elbow pronation, shoulder flexion, shoulder abduction and shoulder internal rotation. The algorithms avoid numerical integration of the signals, which allows for long-time estimations without angle estimation drift. The system has been tested both under laboratory and field conditions. Controlled laboratory tests show mean estimation errors between 0.06° and of 1.05°, and standard deviation between 2.18° and 9.20°. Field tests seem to confirm these results when no ferromagnetic materials are close to the measurement system.     

Convergent validity of six methods to assess physical activity in daily life.

The purpose was to examine the agreement (convergent validity) between six common measures of habitual physical activity to estimate durations of light, moderate, vigorous, and total activity in a range of free-living individuals. Over 7 consecutive days, 49 ethnic Chinese (30 men, 19 women), aged 15-55 yr, wore a Polar heart rate monitor, a uniaxial MTI, and triaxial Tritrac accelerometer, plus a Yamax pedometer for > or = 600 min/day. They also completed a daily physical activity log and on day 8 a Chinese version of the 7-day International Physical Activity Questionnaire. At each level of activity, there was good agreement between the two questionnaire-derived instruments and the two accelerometry-derived instruments, but wide variation across different instruments, with two- to fourfold differences in mean durations often seen. The heart rate monitor overestimated light activity and underestimated moderate activity compared with all other measures. Spearman correlation coefficients were low to moderate (0.2-0.5) across most measures of activity, with the pedometer showing correlations with total activity that were often superior to the other movement sensors. We conclude that, with the use of commonly accepted cut points for defining light, moderate, vigorous, and total activity, little convergent validity across the instruments was evident, suggesting these measures are sampling different levels of habitual physical activity and care is needed when comparing their results. To provide a more stable comparison of activity among different people, across studies, or against accepted physical activity promotion guidelines, further work is needed to fine tune the different cut points across a range of common activity monitors to provide more consistent results during free-living conditions.     

Multichannel,Line-Monitoring Sensing Approach Based on Long-Range Surface Plasmons

The refractive index resolution of a surface plasmon resonance (SPR) sensor has been significantly improved these years; however, higher sensing performance is always desired. In this work, we propose a line-monitoring, long-range SPR sensor whose resolution is much better than conventional SPR sensors. Also, in contrast to mono-channel detection, multichannel detection, using line-monitoring technique, can detect multiple channels concurrently. In this way, this system achieves a refractive index resolution of 4.0?×?10^??7 refractive index units and can monitor multiple molecular interactions simultaneously. Finally, a model experiment detecting the Escherichia coli bacteria has demonstrated the potential for biomedical applications of this system.     

Questionable compensation claims; principles of special examination

In deciding a disputed claim of disability arising from occupation, physicians should ascertain whether a patient's medical history has any bearing on the disability; they should attempt psychologic evaluation of the patient as it may reflect on the conditions they observe in physical examination; they should investigate symptoms complained of by the patient rather than accept them as prima facie evidence of disability; and they must have knowledge of the extent to which an injury can cause disability. It is urged that standards of physical ability and disability, as well as of other physical factors which may affect compensation claims, be established by organized research.     

QUESTIONABLE COMPENSATION CLAIMS—Principles of Special Examination

In deciding a disputed claim of disability arising from occupation, physicians should ascertain whether a patient''s medical history has any bearing on the disability; they should attempt psychologic evaluation of the patient as it may reflect on the conditions they observe in physical examination; they should investigate symptoms complained of by the patient rather than accept them as prima facie evidence of disability; and they must have knowledge of the extent to which an injury can cause disability.It is urged that standards of physical ability and disability, as well as of other physical factors which may affect compensation claims, be established by organized research.     

Recognizing Complex Upper Extremity Activities Using Body Worn Sensors

To evaluate arm-hand therapies for neurological patients it is important to be able to assess actual arm-hand performance objectively. Because instruments that measure the actual quality and quantity of specific activities in daily life are lacking, a new measure needs to be developed. The aims of this study are to a) elucidate the techniques used to identify upper extremity activities, b) provide a proof-of-principle of this method using a set of activities tested in a healthy adult and in a stroke patient, and c) provide an example of the method’s applicability in daily life based on readings taken from a healthy adult. Multiple devices, each of which contains a tri-axial accelerometer, a tri-axial gyroscope and a tri-axial magnetometer were attached to the dominant hand, wrist, upper arm and chest of 30 healthy participants and one stroke patient, who all performed the tasks ‘drinking’, ‘eating’ and ‘brushing hair’ in a standardized environment. To establish proof-of-principle, a prolonged daily life recording of 1 participant was used to identify the task ‘drinking’. The activities were identified using multi-array signal feature extraction and pattern recognition algorithms and 2D-convolution. The activities ‘drinking’, ‘eating’ and ‘brushing hair’ were unambiguously recognized in a sequence of recordings of multiple standardized daily activities in a healthy participant and in a stroke patient. It was also possible to identify a specific activity in a daily life recording. The long term aim is to use this method to a) identify arm-hand activities that someone performs during daily life, b) determine the quantity of activity execution, i.e. amount of use, and c) determine the quality of arm-hand skill performance.     

An early warning system for aquatic environment state monitoring based on an analysis of mussel valve movements

An early warning system for biological monitoring of aquatic environment is proposed, which is based on an analysis of mussel valve movements. It consists of an analog monitor of an original design (analog recorder and analyzer of opening/closing of valves in a group of mussels) and outside devices (multimeters, computers, and mobile phones). In the monitor, an analysis of the state of valve position sensors, summing/averaging of voltage values, and generation of a warning signal are performed in the analog mode. The proposed system (a) diagnoses the state of valve position sensors, (b) determines the voltage representing the average valve opening in a group of mussels (6–12 individuals), (c) generates a warning signal; and, by means of peripheral devices, (d) registers the average voltage of sensors and (e) transmits a warning signal via a mobile communication net. The system can provide an addition (and, sometimes, an alternative) to complicated digital systems analogous to MosselMonitor®.     

Impact of middle and lower jugular neck dissection on supraclavicular lymph node metastasis from endometrial carcinoma

ABSTRACT: Supraclavicular lymph node metastasis from endometrial carcinoma is considerably rarer than metastasis from uterine cervical cancer. To date, there have been no reported cases regarding systematic neck dissection as a salvage treatment. In this report, we describe the neck dissection procedure carried out on a 74-year-old woman with supraclavicular lymph node metastasis. Our objective was to histologically determine the origin of the metastasis while simultaneously providing appropriate treatment. The patient's past medical history included two prior cases of cancer: rectal cancer 7?years earlier and endometrial adenocarcinoma 4?years earlier. We determined that middle and lower jugular neck dissection was appropriate in treating this case based on the results of our preoperative FDG-PET and tumor markers. This surgery provided histological evidence that metastasis occurred from endometrial carcinoma. Middle and lower jugular neck dissection was expected to improve the patient's prognosis without impacting the patient's active daily life. We have continued to monitor the patient closely over an extended period.     

Ambulatory measurement of arm orientation

In order to evaluate the impact of neuromuscular disorders affecting the upper extremities, the functional use of the arm need to be evaluated during daily activities. A system suitable for measuring arm kinematics should be ambulatory and not interfere with activities of daily living. A measurement system based on miniature accelerometers and gyroscopes is adequate because the sensors are small and do not suffer from line of sight problems. A disadvantage of such sensors is the cumulative drift around the vertical and the problems with aligning the sensor with the segment. A method that uses constraints in the elbow to measure the orientation of the lower arm with respect to the upper arm is described. This requires a calibration method to determine the exact orientation of each of the sensors with respect to the segment. Some preliminary measurements were analyzed and they indicated a strong reduction in orientation error around the vertical. It seemed that the accuracy of the method is limited by the accuracy of the sensor to segment calibration.     

医学病例在高校普通遗传学教学中的运用

遗传学是生命科学、医学、农学等相关领域的核心课程。作为21世纪生命科学中发展最为迅速的学科之一,教学内容复杂、更新快,遗传学知识对人一生的影响也日益增强,特别是与医学相关的遗传学知识更是受到大众关注。为使学生更容易理解深奥的遗传学知识,使教学内容更贴近生活,在教学过程中引入医学病例,将相应的医学病例同遗传学理论知识结合并作出适当的延伸,将有利于提高学生的遗传学知识综合分析能力,同时提高学生的学习积极性和实用技能。本文根据现代遗传学教学体系,引入相应的医学病例,强调培养学生综合遗传分析能力,为综合性大学、师范院校的普通遗传学教学提供参考。     

电子病历系统在医院信息管理系统中应用初探

电子病历系统是通过计算机等电子设备为载体,对医院患者的诊疗活动进行数字化记录的软件。电子病历中详细记录了医嘱、病程、过敏史、影像检查结果、出院记录等多项医疗数据。电子病历完整、系统、科学地记录了患者身体健康情况以及历次就诊记录,通过一个维度将患者内部不同层次的信息有机的联系在一起。与传统的纸张病历相比,电子病历可以迅速实现不同时间、不同医院医疗信息的高效整合以及信息共享,为临床诊疗提供大量科学准确的信息,大大提高医院的服务效率。本文通过电子病历系统在医院信息管理系统中的应用情况进行简要分析,以期提高电子病历系统在临床中解决实际医疗问题的能力。