Medical devices, the FDA, and the home healthcare clinician.

This article introduces the U.S. Food and Drug Administration's (FDA's) MedWatch adverse event reporting program that consumers and healthcare professionals can use to voluntarily report potential problems associated with medical devices. It discusses devices commonly used in the home and other "nonclinical" environments and suggests what clinicians can do when encountering device problems or issues. With the increasing use of medical devices in the home and other nonclinical environments, it is becoming more important for users and caregivers to participate in voluntary reporting to help the FDA best address medical device problems that may be unique to these environments.

Software-related recalls: an analysis of records.

Public and internal databases were examined to evaluate software-related recalls in the medical device industry sector. In the analysis of recalls reported from 2005 through 2011, 19.4% of medical device recalls are related to software. This paper includes analysis results, challenges faced in determining the causes, and examples and trends in software-related recalls. This information can be useful in enhancing our understanding of why medical devices fail, and it can help to improve medical device safety, and patient and public health.

A low cost instrumented glove for extended monitoring and functional hand assessment.

A wearable finger flexion monitor developed to measure hand function in individuals with hand dysfunction was evaluated for feasibility, measurement repeatability and reliability, fidelity of wireless transmission, and user acceptance. Configuration of the monitor allows use in situations when a traditional measurement glove cannot be worn. Five healthy individuals participated in the study of repeatability, while 10 healthy individuals and 10 individuals with acquired brain injury participated in trials to assess feasibility and user comfort. Repeatability results showed an overall error of 3.4 degrees , compared to 5.5 degrees and 5.7 degrees reported with other sensor gloves, and to manual measurements (5-8 degrees). Intraclass coefficient of reliability (using coefficient alpha) averaged 0.95. User feedback regarding comfort of the monitor was very high. Loss of data during wireless transmission was no greater than 1.2%. Results demonstrate that the monitor has a strong potential to be used as a tool for objective hand function evaluation in the home and community for both short- and long-term monitoring.

Head-mounted displays for clinical virtual reality applications: pitfalls in understanding user behavior while using technology.

The use of virtual environments with head-mounted displays (HMDs) offers unique assets to the evaluation and therapy of clinical populations. However, research examining the effects of this technology on clinical populations is sparse. Understanding how wearers interact with the HMD is vital. Discomfort leads to altered use of the HMD that could confound performance measures; the very measures which might be used as tools for clinical decision making. The current study is a post-hoc analysis of the relationship between HMD use and HMD comfort. The analysis was conducted to examine contributing factors for a high incidence of simulator sickness observed in an HMD-based driving simulator. Pearson correlation analysis was used to evaluate objective and subjective measures of HMD performance and self-reported user comfort ratings. The results indicated weak correlations between these variables, indicating the complexity of quantifying user discomfort and HMD performance. Comparison of two case studies detailing user behavior in the virtual environment demonstrates that selected variables may not capture how individuals use the HMD. The validity and usefulness of the HMD-based virtual environments must be understood to fully reap the benefits of virtual reality (VR) in rehabilitation medicine.

Measuring finger flexion and activity trends over a 25 hour period using a low cost wireless device.

The goal of this research was to evaluate the usefulness of a wireless custom monitor in measuring real-time finger posture over an extended period of time as the wearer goes about daily life activities. One individual wore the device for 25 continuous hours in the research facility and at home. Initial data analysis methods have been presented to explore different aspects of hand activity over time. Evaluating mean flexion over five minute intervals reveals common hand postures assumed throughout the day, while total joint excursion over longer intervals highlights periods of inactivity associated with sleep or rest, as well as periods of higher intensity activities that can be used to evaluate compliance with physical therapy and home rehabilitation instructions.

Stopping behavior in a VR driving simulator: a new clinical measure for the assessment of driving.

The driving privilege is a critical component of independent living for individuals who have acquired a brain injury. To date, measures of driving capacity following neurological compromise remain limited to gross performance measures, such as subjective behind the wheel evaluations. The current study demonstrates the use of a virtual reality (VR) driving simulator to provide objective and precise measures of driving behavior not previously available for clinical assessment. Driving performance related to Stop Sign (SS) intersections are compared between adults with and without acquired brain injury. The findings indicate that new driving performance measures can be calculated with VR driving simulations, and that these measures may have further implications for examining driving capacity following neurological compromise.

Design considerations for a wearable monitor to measure finger posture.

BACKGROUND: Objective measures of hand function as individuals participate in home and community activities are needed in order to better plan and evaluate rehabilitation treatments. Traditional measures collected in the clinical setting are often not reflective of actual functional performance. Recent advances in technology, however, enable the development of a lightweight, comfortable data collection monitor to measure hand kinematics. METHODS: This paper presents the design analysis of a wearable sensor glove with a specific focus on the sensors selected to measure bend. The most important requirement for the glove is easy donning and removal for individuals with significantly reduced range of motion in the hands and fingers. Additional requirements include comfort and durability, cost effectiveness, and measurement repeatability. These requirements eliminate existing measurement gloves from consideration. Glove construction is introduced, and the sensor selection and glove evaluation process are presented. RESULTS: Evaluation of commercial bend sensors shows that although most are not appropriate for repeatable measurements of finger flexion, one has been successfully identified. A case study for sensor glove repeatability using the final glove configuration and sensors does show a high degree of repeatability in both the gripped and flat hand positions (average coefficient of variability = 2.96% and 0.10%, respectively). CONCLUSION: Measuring functional outcomes in a portable manner can provide a wealth of information important to clinicians for the evaluation and treatment of movement disorders in the hand and fingers. This device is an important step in that direction as both a research and an evaluation method.

Outcome assessment for spasticity management in the patient with traumatic brain injury: the state of the art.

The objective of this article was to (1) review the engineering and medical literature to structure the available information concerning the assessment of spasticity in the neurological population; (2) to discuss the strengths and weaknesses of the different methods currently in use in spasticity assessment; and (3) make recommendations for future efforts in spasticity outcome assessment. Spasticity textbooks, Web sites, and OVID, IEEE, and Medline searches from 1966 through 2003 of spasticity, quantitative measure, or outcome assessment in the rehabilitation population were used as data sources. Over 500 articles were reviewed. Articles that discussed outcome measures used to assess interventions and evaluation of spasticity were included. Authors reviewed the articles looking at inclusion criteria, data collection, methodology, assessment methods, and conclusions for validity and relevance to this article. Issues such as clinical relevance, real-world function and lack of objectivity, and time consumed during performance are important issues for spasticity assessment. Some measures such as the Ashworth Scale remain in common use secondary to ease of use despite their obvious functional limitations. More functional outcome goals are plagued by being more time consuming and a general inability to demonstrate changes after an intervention. This may be secondary to the other factors that combine with spasticity to cause dysfunction at that level. Quantitative metrics can provide more objective measurements but their clinical relevance is sometimes problematic. The assessment of spasticity outcome is still somewhat problematic. Further work is necessary to develop measures that have real-world functional significance to both the individuals being treated and the clinicians. A lack of objectivity is still a problem. In the future it is important for clinicians and the engineers to work together in the development of better outcome measures.