Tamara Hayes

Tamara Hayes
Oregon Health and Science University | OHSU · Department of Biomedical Engineering

About

64
Publications
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2,116
Citations

Publications

Publications (64)
Article
Introduction: There is an unmet need for effective methods for conducting dementia prevention trials. Methods: Home-based assessment study compared feasibility and efficiency, ability to capture change over time using in-home instruments, and ability to predict cognitive conversion using predefined triggers in a randomized clinical trial in (1)...
Article
Full-text available
Introduction: Increased variability in motor function has been observed during the initial stages of cognitive decline. However, the natural variability of postural control, as well as its association with cognitive status and decline, remains unknown. The objective of this pilot study was to characterize the day-to-day variability in postural sway...
Patent
Embodiments provide systems, methods and apparatuses for monitoring the sleep of a subject in a home environment. In embodiments, load cells placed under bed supports may be coupled to a computing device that may process the load cell data to detect disordered breathing. In some embodiments, a computing device may apply a pattern recognition algori...
Article
Objectives To ascertain the association between self-report of low mood and unobtrusively measured behaviors (walking speed, time out of residence, frequency of room transitions, and computer use) in community-dwelling older adults using novel monitoring technologies.DesignLongitudinal cohort study of older adults whose homes were outfitted with ac...
Article
Full-text available
Fundamental laws governing human mobility have many important applications such as forecasting and controlling epidemics or optimizing transportation systems. These mobility patterns, studied in the context of out of home activity during travel or social interactions with observations recorded from cell phone use or diffusion of money, suggest that...
Article
We explored the relationship between sleep disturbances and mild cognitive impairment (MCI) in community-dwelling seniors. Recent evidence suggests that sleep habits are differentially compromised in different subtypes of MCI, but the relationship between sleep disruption and MCI remains poorly understood. We gathered daily objective measures of sl...
Conference Paper
Movement in bed may be an indicator of health problems, i.e., the alteration of the pattern or amount of motor activity can be a disease marker. It can reflect illnesses ranging from flu to depression, pain, or the side effects of certain treatments. There are also motor disturbances that are triggered by sleep such as restless legs syndrome and pe...
Article
Background: Mild disturbances of higher order activities of daily living are present in people diagnosed with mild cognitive impairment (MCI). These deficits may be difficult to detect among those still living independently. Unobtrusive continuous assessment of a complex activity such as home computer use may detect mild functional changes and ide...
Article
The healthcare system is in crisis due to challenges including escalating costs, the inconsistent provision of care, an aging population, and high burden of chronic disease related to health behaviors. Mitigating this crisis will require a major transformation of healthcare to be proactive, preventive, patient-centered, and evidence-based with a fo...
Article
Sleep apnea is a serious condition that afflicts many individuals and is associated with serious health complications. Polysomnography, the gold standard for assessing and diagnosing sleep apnea, uses breathing sensors that are intrusive and can disrupt the patient's sleep during the overnight testing. We investigated the use of breathing signals d...
Article
This report describes the baseline experience of the multicenter, Home-Based Assessment study, designed to develop methods for dementia prevention trials using novel technologies for test administration and data collection. Nondemented individuals of 75 years of age or more were recruited and evaluated in-person using established clinical trial out...
Article
Full-text available
Quality of sleep is an important attribute of an individual's health state and its assessment is therefore a useful diagnostic feature. Changes in the patterns of mobility in bed during sleep can be a disease marker or can reflect various abnormal physiological and neurological conditions. This paper describes a method for detection of movement in...
Article
Full-text available
Poor quality of sleep increases the risk of many adverse health outcomes. Some measures of sleep, such as sleep efficiency or sleep duration, are calculated from periods of time when a patient is asleep and awake. The current method for assessing sleep and wakefulness is based on polysomnography, an expensive and inconvenient method of measuring sl...
Article
Full-text available
With the rising age of the population, there is increased need to help elderly maintain their independence. Smart homes, employing passive sensor networks and pervasive computing techniques, enable the unobtrusive assessment of activities and behaviors of the elderly which can be useful for health state assessment and intervention. Due to the multi...
Article
Full-text available
Executive dysfunction has previously been found to be a risk factor for falls. The aim of this study is to investigate the association between executive dysfunction and risk of falling and to determine if this association is independent of balance. Participants were 188 community-dwelling individuals aged 65 and older. All participants underwent ba...
Article
Physical performance measures predict health and function in older populations. Walking speed in particular has consistently predicted morbidity and mortality. However, single brief walking measures may not reflect a person's typical ability. Using a system that unobtrusively and continuously measures walking activity in a person's home we examined...
Article
Individuals who suffer from acid reflux at night, who snore chronically, or who have sleep apnea are frequently encouraged to sleep in a particular lying position. Side sleeping decreases the frequency and severity of obstructive respiratory events (e.g. apnea and hypopnea) in patients with positional sleep apnea. It has been suggested that individ...
Article
Full-text available
Scratching is a symptom of many dermatological disorders, especially atopic dermatitis. For the development of anti-itch medications, there is a need for objective measures of scratching. Wrist actigraphy (monitoring wrist and hand movements with micro-accelerometers) is a promising method for assessing scratching; however, currently available tech...
Article
Full-text available
Gait velocity has repeatedly been shown to be an important indicator and predictor of both cognitive and physical function, especially in elderly. However, clinical gait assessments are conducted infrequently and cannot distinguish between abrupt changes in function and changes that occur more slowly over time. Collecting gait measurements continuo...
Article
Full-text available
Ubiquitous and unobtrusive in-home monitoring has the potential to detect physical and mental decline earlier and with higher precision than current clinical methods. However, given that this field is in its infancy, the specific metrics through which these changes are detected are not well defined. The work presented here offers room-transitions,...
Article
Sleep is characterized by episodes of immobility interrupted by periods of voluntary and involuntary movement. Increased mobility in bed can be a sign of disrupted sleep that may reduce sleep quality. This paper describes a method for classification of the type of movement in bed using load cells installed at the corners of a bed. The approach is b...
Poster
Background: Increased cognitive and motor test-to-test variability are associated with Mild Cognitive Impairment (MCI). Home-based, unobtrusive and continuous assessment of walking speed may provide a means of capturing early changes in the real-world trajectory of activity variance characterizing MCI. We examined whether long-term in-home assessme...
Article
Full-text available
To describe a longitudinal community cohort study, Intelligent Systems for Assessing Aging Changes, that has deployed an unobtrusive home-based assessment platform in many seniors homes in the existing community. Several types of sensors have been installed in the homes of 265 elderly persons for an average of 33 months. Metrics assessed by the sen...
Article
Full-text available
Motor speed is an important indicator and predictor of both cognitive and physical function. One common assessment of motor speed is the finger-tapping test (FTT), which is typically administered as part of a neurological or neuropsychological assessment. However, the FTT suffers from several limitations, including infrequent in-person administrati...
Article
Full-text available
In-home monitoring of gait velocity with passive PIR sensors in a smart home has been shown to be an effective method of continuously and unobtrusively measuring this important predictor of cognitive function and mobility. However, passive measurements of velocity are nonspecific with regard to who generated each measurement or walking event. As a...
Article
Full-text available
In this paper we describe a preliminary modeling and analysis of a unique data set comprising unobtrusive and continuous measurements of gait velocity in the elder participants' residences. The data have been collected as a part of a longitudinal study aimed at early detection of cognitive decline. We motivate these analyses by first presenting evi...
Article
Full-text available
A patient's sleep/wake schedule is an important step underlying clinical evaluation of sleep-related complaints. Aspects related to timing of a person's sleep routine provide important clues regarding diagnosis and treatments. Solutions for sleep complaints may sometimes rely solely on changes in habits and life style, based on what is learned from...
Article
Full-text available
Disrupted sleep patterns are a significant problem in the elderly, leading to increased cognitive dysfunction and risk of nursing home placement. A cost-effective and unobtrusive way to remotely monitor changing sleep patterns over time would enable improved management of this important health problem. We have developed an algorithm to derive sleep...
Article
This report describes a pilot study to evaluate feasibility of new home-based assessment technologies applicable to clinical trials for prevention of cognitive loss and Alzheimer disease. Community-dwelling nondemented individuals >or=75 years old were recruited and randomized to 1 of 3 assessment methodologies: (1) mail-in questionnaire/ live tele...
Poster
Full-text available
In 113 non-demented ISAAC (Intelligent Systems for Assessing Aging Change) cohort (Kaye, 2008) seniors living independently (mean age 84; CDR ≤ 0.5) multiple daily walking episodes were unobtrusively recorded as subjects traversed a line of passive infra-red motion sensors placed strategically in their home (figure 1) for a mean of 319 ±127 days. D...
Chapter
Full-text available
We discuss a new approach to patients' adherence to enhance to their medication-taking regimen by developing a context-aware alerting system that would optimize the expected utility of alerts. Each patient's instantaneous context is assessed using a real-time sensor network deploying a variety of sensors. The alerts are generated to optimize the ex...
Article
Full-text available
Poor medication adherence is one of the major causes of illness and of treatment failure in the United States. The objective of this study was to conduct an initial evaluation of a context-aware reminder system, which generated reminders at an opportune time to take the medication. Ten participants aged 65 or older, living alone and managing their...
Article
Accurate assessment of mobility in bed presents challenges to clinicians and researchers alike. Mobility is traditionally assessed by either overnight polysomnograph recording or wrist actigraphy. This paper describes an alternative system for unobtrusive and continuous monitoring of sleep movements that uses load sensors installed at the corners o...
Conference Paper
Full-text available
Unobtrusive in-home computer monitoring could one day be used to deliver cost-effective diagnostic information about the cognitive abilities of the elderly. This could allow for early detection of cognitive impairment and would additionally be coupled with the cost advantages that are associated with a semi-automated system. Before using the comput...
Article
Full-text available
Sleep disturbances are prevalent, financially taxing, and have a negative effect on health and quality of life. One of the most common sleep disturbances is obstructive sleep apnea-hypopnea syndrome (OSAHS) which frequently goes undiagnosed. The gold standard for diagnosing OSAHS is polysomnography (PSG)-a procedure that is inconvenient, time-consu...
Conference Paper
Full-text available
Walking speed and activity are important measures of functional ability in the elderly. Our earlier studies have suggested that continuous monitoring may allow us to detect changes in walking speed that are also predictive of cognitive changes. We evaluated the use of passive infrared (PIR) sensors for measuring walking speed in the home on an ongo...
Article
Full-text available
This was a cross-sectional study of the ability of independently living healthy elders to follow a medication regimen. Participants were divided into a group with High Cognitive Function (HCF) or Low Cognitive Function (LCF) based on their scores on the ADAS-Cog. Thirty-eight participants aged 65 or older and living independently in the community f...
Article
Quality of sleep is an important attribute of an individual's health state and its assessment is therefore a useful diagnostic feature. Changes in the patterns of motor activities during sleep can be a disease marker, or can reflect various abnormal physiological and neurological conditions. Presently, there are no convenient, unobtrusive ways to a...
Article
Timely detection of early cognitive impairment is difficult. Measures taken in the clinic reflect a single snapshot of performance that might be confounded by the increased variability typical in aging and disease. We evaluated the use of continuous, long-term, and unobtrusive in-home monitoring to assess neurologic function in healthy and cognitiv...
Conference Paper
Accurate assessment of mobility in bed presents challenges to clinicians and researchers alike. It is traditionally performed by either overnight polysomnograph recording or wrist-actigraphy. A different approach is instrumenting the bed itself rather than the sleeping subject. This paper describes an alternative system for unobtrusive monitoring o...
Article
Although the "-omics" revolution has firmly established the importance of biomarkers of disease, the field of behavioral markers of disease is still emerging. In order to accelerate and scale research around behavioral disease markers, Intel's Digital Health group and the Oregon Health and Science University (OHSU) have created a research commons -...
Article
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The use of pervasive technologies to enable continuous patient monitoring and assessment in various setting outside of hospitals, lowering healthcare costs and allowing early detection of problems is discussed. A modified security system technology is a less obstructive alternative for home monitoring. Recent advances in wireless systems provide th...
Article
Full-text available
Poor medication adherence is a serious medical problem, particularly in older adults. Various solutions have been developed to remind people to take their medications, but these systems are usually simple time-based alarm systems that are not particularly effective. We describe a system that is context aware, and that utilizes information about pas...
Article
Full-text available
This paper describes a model-based approach to the unobtrusive monitoring of elders in their home environment to assess their health, daily activities, and cognitive function. We present a semi-Markov model representation with automated learning to characterize individual elder's mobility in the home environment. The assessed mobility can be used t...
Article
Full-text available
We have developed an instrumented pillbox, called a MedTracker, which allows monitoring of medication adherence on a continuous basis. This device improves on existing systems by providing mobility, frequent and automatic data collection, more detailed information about non-adherence and medication errors, and the familiar interface of a 7-day drug...
Article
Subpopulations of pyramidal neurons in the neocortex have been shown to contain nonphosphorylated neurofilament protein (NPNFP) and calbindin D25K (Morrison et al., 1987; Campbell and Morrison, 1989; Hot et al., 1990; Kobayashi et al., 1990; Hof and Morrison, 1991; Mosulam and Geula, 1991). However, it is not known what relations, if any, exist bet...
Article
Full-text available
Cognitive or motor function decline are major causes of loss of independent living among the aged. Several methods employing ubiquitous or unobtrusive technologies have been proposed for application toward in-home assessment to identify clinically meaningful change. Most attempts at multi-dimensional home monitoring have been on a limited scale. Th...
Article
The current paradigm of clinic-focused healthcare is challenged by growing numbers of aging baby boomers and the concomitant cost of managing chronic health conditions. We have begun investigating an alternative to clinic-based health assessments, in which pervasive technologies are used to enable continuous monitoring and assessment of patients in...
Article
Full-text available
T he ability to assess the cognitive state of an individual is important for both clini-cal care and for our understanding of the neurological underpinning of cognitive func-tion. Furthermore, understanding changes asso-ciated with aging and disease is a critical component of care for the aging populations of the world. Cognitive functioning is one...

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