Validation of an ambient measurement system (AMS) for physical activities in a paediatric population.

Ambient measurement systems (AMSs) can enable continuous assessment of functional performance at home, increasing the availability of data for monitoring of neuromuscular disease. An AMS passively measures movement whenever someone is in range of the sensor, without the need for any wearable sensors. The current study evaluates the performance of an AMS for three metrics associated with functional assessments in Duchenne muscular dystrophy (DMD): ambulation speed, rise-to-stand speed and arm-raise speed. Healthy paediatric subjects performed a series of functional tasks and were graded by both a human rater and an AMS. Linear mixed-effect models were fit to calculate agreement between the two measurement methods. For all activities, the AMS and human rater supplied similar measurements of average speed, with correlation coefficients of 0.76-0.92 and systematic differences ranging in magnitude from 0 to 0.48 m per second. The largest systematic difference was for the 10-m run, which was likely due to human rater reaction time. Systematic differences in arm-raise measurements were due to incomplete execution of movements by test participants. These results are consistent with previous studies comparing automated and manual measurements of movement. This study demonstrates that an AMS device is able to measure ambulation speed, rise-to-stand speed and arm-raise speed in a paediatric population in a controlled setting without the need for complicated installation, calibration or worn sensors.

Walking speed measurement with an Ambient Measurement System (AMS) in patients with multiple sclerosis and walking impairment.

BACKGROUND: Walking speed is an important measure of gait impairment in multiple sclerosis (MS). The clinical assessment of walking speed requires dedicated time, space, and personnel, and may not accurately gauge real-world performance. The term "Ambient Measurement System" (AMS) refers to a new class of device that passively measures walking speed at home, without the need for dedicated space or specialized setup. This study compared an AMS, Echo5D, versus in-clinic standard measures of walking speed on a straight path. METHODS: Twenty participants with MS and walking impairment were recruited from the Cleveland Clinic Mellen Center for MS. Each participant traversed an electronic GAITRite CIRFace (GC) sensor mat four times (two at comfortable pace, two at fast pace). Each participant then performed the Timed 25-Foot Walk (T25FW) twice, measured by a manual stopwatch (SW). All traversals were simultaneously measured by an array of Echo5D devices. Echo5D speeds were correlated with the Patient-Determined Disease Steps and the MS Walking Scale-12 patient-reported outcomes. RESULTS: Pearson correlations between Echo5D and clinical tests ranged from 0.89 to 0.98 (p < 0.0001). No statistically significant bias was found between Echo5D and GC. A small statistically significant bias was found between Echo5D and SW, with Echo5D reporting approximately 5% faster walking speeds in aggregate. CONCLUSIONS: Among MS patients with walking impairments, the Echo5D AMS acquired walking speeds which were closely correlated with the standard measures of GC and SW. The strong agreement supports the use of Echo5D to assess in-home, real-world walking performance in MS.

Movement measurements at home for multiple sclerosis: walking speed measured by a novel ambient measurement system.

BACKGROUND: Gait disturbance is a major contributor to clinical disability in multiple sclerosis (MS). A sensor was developed to assess walking speed at home for people with MS using infrared technology in real-time without the use of wearables. OBJECTIVE: To develop continuous in-home outcome measures to assess gait in adults with MS. METHODS: Movement measurements were collected continuously for 8 months from six people with MS. Average walking speed and peak walking speed were calculated from movement data, then analyzed for variability over time, by room (location), and over the course of the day. In-home continuous gait outcomes and variability were correlated with standard in-clinic gait outcomes. RESULTS: Measured in-home average walking speed of participants ranged from 0.33 m/s to 0.96 m/s and peak walking speed ranged from 0.89 m/s to 1.51 m/s. Mean total within-participant coefficient of variation for daily average walking speed and peak walking speed were 10.75% and 10.93%, respectively. Average walking speed demonstrated a moderately strong correlation with baseline Timed 25-Foot Walk (rs = 0.714, P = 0.111). CONCLUSION: New non-wearable technology provides reliable and continuous in-home assessment of walking speed.

Validation of an ambient measurement system (AMS) for walking speed.

Walking speed is an important indicator of worsening in a variety of neurological and neuromuscular diseases, yet typically is measured only infrequently and in a clinical setting. Passive measurement of walking speed at home could provide valuable information to track the progression of many neuromuscular conditions. The purpose of this study was to validate the measurement of walking speed by a shelf-top ambient measurement system (AMS) that can be placed in a patient's home. Twenty-eight healthy adults (16 male, 12 female) were asked to walk three pre-defined routes two times each (total of 168 traversals). For each traversal, walking speed was measured simultaneously by five sources: two independent AMSs and three human timers with stopwatches. Measurements across the five sources were compared by generalised estimating equations (GEE). Correlation coefficients compared pairwise for walking speeds across the two AMSs, three human timers, and three routes all exceeded 0.86 (p < .0001), and for AMS-to-AMS exceeded 0.92 (p < .0001). Aggregated across all routes, there was no significant difference in measured walking speeds between the two AMSs (p = .596). There was a statistically significant difference between the AMSs and human timers of 8.5 cm/s (p < .0001), which is comparable to differences reported for other non-worn sensors. The tested AMS demonstrated the ability to automatically measure walking speeds comparable to manual observation and recording, which is the current standard for assessing walking speed in a clinical setting. The AMS may be used to detect changes in walking speed in community settings.

Treatment intensification and blood glucose control among hospitalized diabetic patients.

BACKGROUND: Hyperglycemia is common among diabetic inpatients, and has been linked to adverse outcomes. However, antihyperglycemic treatment is seldom intensified in noncritical care patients, and the relationship between intensification frequency and glucose control is poorly understood. We evaluated the relationship between treatment intensification and changes in blood glucose in hospitalized diabetic patients. DESIGN: We retrospectively analyzed 3,613 hospitalized diabetic patients who were admitted to the hospital between January 2003 and August 2004, were not hospitalized in an ICU, were not prescribed IV insulin or total parenteral nutrition (TPN), had a length of stay of at least 3 days, and had at least one point-of-care blood glucose measurement. A linear model was used to assess the relationship between intensification of antihyperglycemic medications and the average daily change in point-of-care glucose measurements. RESULTS: Hyperglycemia (>180 mg/dL) was documented at least once for 82.5% of patient admissions. Antihyperglycemic treatment was intensified for 22.0% of days with hyperglycemia. Intensifications of scheduled and sliding scale insulin, but not oral medications, were associated with a 11.1 mg/dL (p < 0.0001) and 12.2 mg/dL (p < 0.0001) reduction in the average daily glucose, respectively. Hypoglycemia (<50 mg/dL) was documented on 2.2% of days after antihyperglycemic treatment intensification. CONCLUSION: In this cohort, lack of treatment intensification in response to inpatient hyperglycemia was common. Antihyperglycemic treatment intensification was strongly associated with decrease in average daily glucose, while hypoglycemia was uncommon. This suggests that increasing the frequency of treatment intensifications could lead to improved glycemic control in inpatients with diabetes.