In this chapter, we will outline the methodologies that have been successfully developed and utilized by Intel and Technology Research for Independent Living (TRIL) Centre researchers in the design, implementation, deployment, management, and analysis of home- and community-based research pilots. Translating research from the confines of the laboratory to real-world environments of community clinics and people’s homes is challenging. However, when successful, applying that research correctly can deliver meaningful benefits to both patients and clinicians. Leveraging the expertise of multidisciplinary teams is vital to ensuring that all issues are successfully captured and addressed during the project life cycle. Additionally, the end user must be the center of focus during both the development and evaluation phases. Finally, the trial must generate data and results that are sufficiently robust to withstand rigorous review by clinical and scientific experts. This is vital if any new technology solution is to be successful adopted for clinical use.
Home Deployment Elements
The development of sensor systems suitable for home settings, and to a lesser extent community settings, creates significant challenges, including cost, reliability, sensitivity, practicality of installation, and aesthetic considerations. The relative weight of these factors will vary from application to application. In this section, we focus on the considerations that apply to the development of body-worn or ambient sensing solutions.
Home- and Community-Based Sensing
The availability of low-cost, reliable, and intuitive technologies is critical in enabling community- and home-based solutions. While these technologies may not have the ultra-high resolution of systems found in hospital clinics, they can provide the community-based clinicians with a strong indication of whether an issue exists or whether the patient is trending significantly in a manner that warrants referral to a specialist facility for further investigation.
Geriatric medicine makes extensive use of subjective or largely subjective tools to assess the patient. The ability to add insights obtained from patient observation to the result of the tests requires years of specialized training by the clinician. Even if the clinician has the ability to provide an accurate assessment of the patient’s condition, there is no comprehensive quantitative record of the tests. This impacts the ability of the clinician to accurately track whether a prescribed intervention is working appropriately. Sensor systems provide a means to fully capture the spectrum of data available during the tests. Objective measures enable the repeatability and reproducibility of tests, which are important in enabling long-term patient monitoring.
Sensors can play a key role in providing objective cost-effective measurements of patients. New clinical sensor technologies will enable public health policy to move from a reactive to proactive healthcare model. These solutions must process the sensor data, present the data in a manner that enables intuitive interpretation, demonstrate whether and how the patient’s data differs from their comparative population, and allow the clinician to compare the patient’s previous test results. Collectively, these elements can give local health professionals capabilities that have up to now been the preserve of specialist clinicians in specialized clinics. Consequently, the cost of patient treatment should be reduced. Early intervention and proactive patient treatment are often less expensive than reactive treatment in a hospital following a health event.
The current sensor-oriented approaches fall into two broad categories:
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Body-worn applications are primarily used in either assessment and/or monitoring applications.
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Ambient applications are typically used to passively monitor a subject’s behaviors and activity patterns or to trigger actuators to initiate actions, such as switching on lights when a bed exit sensor is triggered during the night.
Although both approaches can utilize common technology elements, they will have differing design considerations and constraints such as contact requirements with the human body, long-term deployments, and data processing requirements.
Body-Worn Assessment Applications
Body-worn sensors (BWS)have been used in a wide variety of physiological and kinematic monitoring applications (Catherwood et al., 2010, Ghasemzadeh et al., 2010, Aziz et al., 2006, Greene et al., 2010). BWS have the potential to support the clinical judgment of community-based practitioners through the provision of objective measures for tests, which are currently administered in a qualitative manner. Because of their small form factor, BWS can provide on-body measurements over extended periods of time. They can also support flexible protocols. Data-forwarding BWS can stream data up to distances of 100 meters from the sensor to the data aggregator. Data logging BWS can record data to local data storage, thus allowing location-independent monitoring (Scanaill et al., 2006). However, the design of the on-body sensor attachments is extremely important. The sensors used to capture the data must ensure that the data collected is of sufficient resolution to prevent motion artifacts corrupting the signal. The method of attachment should also be intuitive and prevent incorrect positioning and orientation of the sensor on the body. Because of these various interrelated requirements, a sensor systems approach will be the most effective method to ensure integrated end-to-end capabilities (see
Chapter 3).
For applications that require long-term monitoring, compliance can be challenging. The patient must remember to reattach the sensor if it has been removed at night, during showering, or for charging. In physiological-sensing applications, the electrode must be carefully designed to minimize skin irritation and ensure good signal quality. Given these considerations, body-worn sensors must be carefully matched to the application. Short-term measurements—such as 24-hour EKG/ECG monitoring or a one-off measurement for diagnostic tests—provide good use cases for BWS. Such applications are supervised in some manner by a healthcare professional, ensuring that the sensor is correctly attached and the data is of the required quality.
Kinematic sensors are increasingly used by research groups for supervised motion analysis applications because their size has no impact on the gait pattern of the subject being tested. They can also provide location-independent monitoring by storing data to an onboard memory card. Gait and balance impairment, one of the most prevalent falls risk factors, can be accurately measured using low-cost kinematic sensor (in other words, accelerometer, gyroscope, or magnetometer) technology. Despite the low-cost of these technologies, they are rarely used outside of a research or clinical environment. There are a few reasons for this. First, many existing technologies do not provide sufficient context for the results they produce and therefore require a level of expertise to interpret. Second, community-based clinicians do not have the time to set up the technology and perform complex protocols as part of their routine examinations. Finally, these technologies are not developed for, or marketed toward, the community clinician. Therefore, most are unaware of the existence of such technologies. Case Study 1 describes a body-worn kinematic sensing application that was designed and developed with these considerations in mind.
Ambient Sensing
Noncontact sensing systems provide 24-hour monitoring of subjects in their home by connecting various sensing technologies, such as passive or active infrared sensors, to a data aggregator. The data aggregator can provide simple storage of the data for offline analysis or can process and forward the data to a back-end infrastructure. Once data is transferred to a back end, it can be processed in application-specific ways. For example, in an activity of daily living (ADL) application, the data can be used in an inference engine (for example, Bayesian and Markov Models) to determine the subject’s ADLs. The determination is based on the interactions detected between the subject and their home environment. Alternatively, the data could be used to identify a change in personal routine, which may indicate an onset of disease. For example, diabetes may be diagnosed by identifying more frequent visits to the bathroom during the night, or dementia may be diagnosed by increasingly erratic movement patterns during the day or night. Other noncontact solutions include the following:
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Activities of daily living (Wood et al., 2008)
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Safety (Lee et al., 2008)
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Location determination (Kelly et al., 2008)
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Gait velocity (Hagler et al., 2010, Hayes et al., 2009)
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Cognition/dementia (Biswas et al., 2010)
Ambient sensors can also be used to provide inputs into actuators or other forms of integrated systems. Pressure sensors can be used in a bedroom to detect when someone exits their bed. They can trigger an action such as lighting a path to the bathroom to prevent accidental trips.
From a user perspective, ambient sensing can engender mixed reactions. On one hand, the systems can provide people with a sense of security, especially those who are living alone. However, they also generate strong negative responses, especially if the person associates the sensor with being monitored by a camera. Good form-factor design can make the sensor less obvious, which helps reduce people’s awareness of them. Battery-powered sensors afford great flexibility in placement and can be placed in unobtrusive locations, unlike mains-powered sensors, which must be placed near a power socket.
User Touch Points
The user touch point is playing an increasingly important role in the design and deployment of monitoring and assessment tools, as solutions are no longer limited to large PCs and laptops. There is increasing interest in exploiting the growing capabilities of smartphones and tablets in a variety of domains, including healthcare (Middleton, 2010). More than 80 percent of doctors now use mobile devices such tablets and smartphones to improve patient care (Bresnick, 2012). Leveraging the capabilities of these low-cost devices for healthcare applications is a logical next step to enable greater access at lower cost to previously silo’ d applications. However, significant focus must be given to the appropriate design of the user interfaces to ensure that applications can be used effectively on smaller screen sizes. Smartphones are already being used by clinicians and medical students to manage e-mails, access online resources, and view medical references. However, for clinical applications, such as viewing lab results or instrumented tests such as ECGs, and electronic prescribing, usage is significantly less (Prestigiacomo, 2010). Despite the sensing, processing, and data storage capabilities of smartphones, they are also not yet commonly applied as clinical data capture/assessment devices.
Smartphones and tablets provide intuitive user interaction, integrated sensing, low-power processing, low-cost data acquisition and storage, and wireless connectivity. Another key advantage of smartphones is the ability to extend the functionality of a device by downloading software applications from online app stores or creating custom applications using the software development kit (SDK) provided by the manufacturer.
The tablet form factor provides a natural and intuitive interaction model for older adults and individuals who have some form of physical or cognitive disability (Smith, 2011). The ability to use a tablet requires little or no training. Applications for older adults such as reminiscing (Mulvenna et al., 2011), language translation (Schmeier et al., 2011), and toilet locations (Barnes et al., 2011) have been recently reported in the literature. The design of the interaction model for the application should be given appropriate attention. The benefit of a simple physical interaction with the device quickly evaporates if the application navigation and interaction are not of equivalent simplicity.
One application focus area that benefits from the easy user interaction, location independence, and large screen size afforded by a tablet is cognitive functional testing. Some cognitive tests simply require the subject to re-create a displayed pattern using a pen and paper. Replicating such a test using a standard computing device, such as a laptop or desktop computer, could present significant usability challenges. Those challenges make it difficult to separate the ability to perform the test from the ability to use the laptop/desktop effectively. Tests built on tablets can address many of these usability issues and also allow the participant to take the test in their preferred location in their own home. The integrated sensors on a pad can also be utilized to improve usability. The pad’s built-in light sensor, for example, can be used to ensure a consistent visual presentation baseline, by detecting the ambient light conditions and automatically adjusting the screen brightness.
Most smartphones are augmented with integrated inertial sensors, including accelerometers and gyroscopes. The availability of this integrated kinematic sensing capability has led to the development of smartphone applications for biometric detection (Mantyjarvi et al., 2005), activity detection (Khan et al., 2010), and motion analysis (LeMoyne et al., 2010). However, there are some limitations to using the integrated sensors in a tablet/phone device, particularly for applications that require consistent sampling rates. Smartphone devices cannot guarantee a consistent sampling rate or sensor sensitivity. In applications where control of these parameters is essential, interfacing the smartphone/tablet device to a known discrete sensor is a more appropriate design choice than using integrated sensors. The development of an Android-based application with discrete body-worn sensors is described in Case Study 1. Stand-alone sensor hubs for smartphones, operating independently of the phone’s CPU, address many of the current deterministic performance limitations.
Televisions have received interest for a number of years as a potential healthcare touch point. Commercial assisted-living products, such as Philip’s Motiva (Philips, 2013) have emerged that are focused on chronic disease management (CDM). Until now, CDM solutions have required the use of a set-top connected to the TV. The emergence of web-enabled televisions containing integrated CPUs and network connectivity from manufacturers such as Samsung, LG, Sony, and Panasonic will provide a new platform for healthcare content consumption in the future. As health-related devices connect to the cloud, data and other analytics-derived information could potentially be consumed through a “smart TV” web interface. However, it is likely to be a number of years before this platform is sufficiently mature to be a viable health platform (Blackburn et al., 2011). Although the user experience on this platform is improving, it is still far from seamless, and significant challenges still remain in delivering a high-quality user interaction experience.
Participant Feedback
The provision of feedback to the end user raises some interesting questions and conflicts, especially if the technology deployment is primarily research oriented. Participants in a trial generally look for feedback on their performance and context for any results obtained and ask questions such as “Does that mean I did well?” Feedback and the manner in which it is delivered to a participant can provide a critical hook in maintaining participant engagement. However, the advantages of providing feedback must be offset against the potential negative influence on the data set acquired during the course of the study. Users who receive feedback may bias the data by over-engaging with the technology or adapting the way they perform the experiment to improve their scores. Ultimately, whether feedback is provided or not, the type of feedback provided will be defined by your research questions.
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