The feasibility of posture and movement detection by accelerometry

The discrimination of postures and movements using a minimal set of uniaxial accelerometers was investigated. Postures and movements were distinguished on the bitsis of the high-pm filtered, rectified and low pass filtered signal of one accelerometer. Postures were discriminated by combining the constant valued signals of the accelerometers, mounted on different segments of the body. One sensor mounted ndiully on the trunc and one mounted radially or tangentially on the upper leg appeared to be suficient to discriminate shnding, sitting and lying. Methods are proposed for the discrimination of different cyclical movements

A novel accelerometry-based algorithm for the detection of step durations over short episodes of gait in healthy elderly.

Background: The assessment of short episodes of gait is clinically relevant and easily implemented, especially given limited space and time requirements. BFS (body-fixed-sensors) are small, lightweight and easy to wear sensors, which allow the assessment of gait at relative low cost and with low interference. Thus, the assessment with BFS of short episodes of gait, extracted from dailylife physical activity or measured in a standardised and supervised setting, may add value in the study of gait quality of the elderly. The aim of this study was to evaluate the accuracy of a novel algorithm based on acceleration signals recorded at different human locations (lower back and heels) for the detection of step durations over short episodes of gait in healthy elderly subjects.Methods: Twenty healthy elderly subjects (73.7 ± 7.9 years old) walked twice a distance of 5 m, wearing a BFS on the lower back, and on the outside of each heel. Moreover, an optoelectronic three-dimensional (3D) motion tracking system was used to detect step durations. A novel algorithm is presented for the detection of step durations from low-back and heel acceleration signals separately. The accuracy of the algorithm was assessed by comparing absolute differences in step duration between the three methods: step detection from the optoelectronic 3D motion tracking system, step detection from the application of the novel algorithm to low-back accelerations, and step detection from the application of the novel algorithm to heel accelerations.Results: The proposed algorithm successfully detected all the steps, without false positives and without false negatives. Absolute average differences in step duration within trials and across subjects were calculated for each comparison, between low-back accelerations and the optoelectronic system were on average 22.4 ± 7.6 ms (4.0 ± 1.3 % of average step duration), between heel accelerations and the optoelectronic system were on average 20.7 ± 11.8 ms (3.7 ± 1.9 %), and between low-back accelerations and heel accelerations were on average 27.8 ± 15.1 ms (4.9 ± 2.5 % of average step duration).Conclusions: This study showed that the presented novel algorithm detects step durations over short episodes of gait in healthy elderly subjects with acceptable accuracy from low-back and heel accelerations, which provides opportunities to extract a range of gait parameters from short episodes of gait

Gait speed assessed by a 4-m walk test is not representative of daily-life gait speed in community-dwelling adults

Objectives: Standardized tests of gait speed are regarded as being of clinical value, but they are typically performed under optimal conditions, and may not reflect daily-life gait behavior. The aim of this study was to compare 4-m gait speed to the distribution of daily-life gait speed. Study design: The cross-sectional Grey Power cohort included 254 community-dwelling participants aged 18 years or more. Main outcome measures: Pearson's correlations were used to compare gait speed assessed using a timed 4-m walk test at preferred pace, and daily-life gait speed obtained from tri-axial lower-back accelerometer data over seven consecutive days. Results: Participants (median age 66.7 years [IQR 59.4–72.5], 65.7% female) had a mean 4-m gait speed of 1.43 m/s (SD 0.21), and a mean 50th percentile of daily-life gait speed of 0.90 m/s (SD 0.23). Ninety-six percent had a bimodal distribution of daily-life gait speed, with a mean 1st peak of 0.61 m/s (SD 0.15) and 2nd peak of 1.26 m/s (SD 0.23). The percentile of the daily-life distribution that corresponded best with the individual 4-m gait speed had a median value of 91.2 (IQR 75.4–98.6). The 4-m gait speed was very weakly correlated to the 1st and 2nd peak (r = 0.005, p = 0.936 and r=0.181, p = 0.004), and the daily-life gait speed percentiles (range: 1st percentile r = 0.076, p = 0.230 to 99th percentile r = 0.399, p < 0.001; 50th percentile r = 0.132, p = 0.036). Conclusions: The 4-m gait speed is only weakly related to daily-life gait speed. Clinicians and researchers should consider that 4-m gait speed and daily-life gait speed represent two different constructs

Instrumented Assessment of Physical Activity Is Associated With Muscle Function but Not With Muscle Mass in a General Population

Objectives: Self-reported physical activity has shown to affect muscle-related parameters. As self-report is likely biased, this study aimed to assess the association between instrumented assessment of physical activity (I-PA) and muscle-related parameters in a general population. Method: Included were 156 young-to-middle-aged and 80 older community-dwelling adults. Seven days of trunk accelerometry (DynaPort MoveMonitor, McRoberts B.V.) quantified daily physical activity (i.e., active/inactive duration, number and mean duration of active/inactive periods, and number of steps per day). Muscle-related parameters included muscle mass, handgrip strength, and gait speed. Results: I-PA was associated with handgrip strength in young-to-middle-aged adults and with gait speed in older adults. I-PA was not associated with muscle mass in either age group. Discussion: The association between I-PA and muscle-related parameters was age dependent. The lack of an association between I-PA and muscle mass indicates the relevance of muscle function rather than muscle mass

Barriers and facilitators for healthcare professionals to the implementation of Multidisciplinary Timely Undertaken Advance Care Planning conversations at the outpatient clinic (the MUTUAL intervention): a sequential exploratory mixed-methods study

BACKGROUND: Advance Care Planning (ACP) enables patients to define and discuss their goals and preferences for future medical treatment and care. However, the structural implementation of ACP interventions remains challenging. The Multidisciplinary Timely Undertaken Advance Care Planning (MUTUAL) intervention has recently been developed which takes into account existing barriers and facilitators. We aimed to evaluate the MUTUAL intervention and identify the barriers and facilitators healthcare professionals experience in the implementation of the MUTUAL intervention and also to identify suggestions for improvement. METHODS: We performed a sequential exploratory mixed-methods study at five outpatient clinics of one, 300-bed, non-academic hospital. Firstly, semi-structured interviews were performed with a purposive sample of healthcare professionals. The content of these interviews was used to specify the Measurement Instrument for Determinants of Innovations (MIDI). The MIDI was sent to all healthcare professionals. The interviews and questionnaires were used to clarify the results. RESULTS: Eleven healthcare professionals participated in the interviews and 37 responded to the questionnaire. Eight barriers and 20 facilitators were identified. Healthcare professionals agreed that the elements of the MUTUAL intervention are clear, correct, complete, and simple - and the intervention is relevant for patients and their proxies. The main barriers are found within the user and the organisational domain. Barriers related to the organisation include: inadequate replacement of staff, insufficient staff, and insufficient time to introduce and invite patients. Several suggestions for improvement were made. CONCLUSION: Our results show that healthcare professionals positively evaluate the MUTUAL intervention and are very receptive to implementing the MUTUAL intervention. Taking into account the suggestions for improvement may enhance further implementation

The development and feasibility study of Multidisciplinary Timely Undertaken Advance Care Planning conversations at the outpatient clinic: the MUTUAL intervention

BACKGROUND: Patients still receive non-beneficial treatments when nearing the end of life. Advance care planning (ACP) interventions have shown to positively influence compliance with end of life wishes. Hospital physicians seem to miss opportunities to engage in ACP, whereas patients visiting the outpatient clinic usually have one or more chronic conditions and are at risk for medical emergencies. So far, implemented ACP interventions have had limited impact. Structural implementation of ACP may be beneficial. We hypothesize that having ACP conversations more towards the end of life and involving the treating physician in the ACP conversation may help patient wishes and goals to become more concrete and more often documented, thus facilitating goal-concordant care. AIM: To facilitate timely shared decision making and increase patient autonomy we aim to develop an ACP intervention at the outpatient clinic for frail patients and determine the feasibility of the intervention. METHODS: The United Kingdom's Medical Research Council framework was used to structure the development of the ACP intervention. Key elements of the ACP intervention were determined by reviewing existing literature and an iterative process with stakeholders. The feasibility of the developed intervention was evaluated by a feasibility study of 20 ACP conversations at the geriatrics and pulmonology department of a non-academic hospital. Feasibility was assessed by analysing evaluation forms by patients, nurses and physicians and by evaluating with stakeholders. A general inductive approach was used for analysing comments. The developed intervention was described using the template for intervention description and replication (TIDieR). RESULTS: We developed a multidisciplinary timely undertaken ACP intervention at the outpatient clinic. Key components of the developed intervention consist of 1) timely patient selection 2) preparation of patient and healthcare professional 3) a scripted ACP conversation in a multidisciplinary setting and 4) documentation. 94.7% of the patients, 60.0% of the nurses and 68.8% of the physicians agreed that the benefits of the ACP conversation outweighed the potential burdens. CONCLUSION: This study showed that the developed ACP intervention is feasible and considered valuable by patients and healthcare professionals

Finding the balance between person-centred and treatment-centred discussions in advance care planning-a qualitative analysis of conversations within the MUTUAL (Multidisciplinary Timely Undertaken Advance Care Planning conversations) intervention using a narrative analysis

INTRODUCTION: Advance care planning (ACP) aims to create conditions for more person-centred care. We aimed to explore variations in person-centred care discussions and treatment-centred care discussions within ACP conversations in the Multidisciplinary Timely Undertaken Advance Care Planning (MUTUAL) intervention and how person-centred care discussions could be encouraged. The MUTUAL intervention consists of the following: (i) timely patient selection, (ii) the patient and healthcare professionals preparing for the conversation, (iii) a scripted ACP conversation in a multidisciplinary setting and (iv) documentation. METHODS: We conducted a narrative analysis of ACP conversations. A narrative summary template was created and used to analyse 18 audio-recordings. RESULTS: We noticed variations in person-centred and treatment-centred focus within the ACP conversations. We identified three important strategies that facilitated person-centred care discussions within ACP conversations. First, healthcare professionals' acceptance that ACP is an individual process. We believe it is important that healthcare professionals recognise and accept where the patient is in his or her individual ACP process; not making decisions right away can also be part of a decisional process. Secondly, exploring the underlying motivation for treatment wishes can give insights into patient's wishes, values and needs. Lastly, healthcare professionals who demonstrated an adaptive, curious and engaged attitude throughout the ACP process achieved more person-centred ACP conversations. This coincided with elaborating on the patient's emotions, fears and worries. CONCLUSION: Person-centred and treatment-centred focus varied within the ACP conversations in the MUTUAL intervention. Certain strategies by healthcare professionals facilitated a more person-centred focus

Potential Markers of Progression in Idiopathic Parkinson’s Disease Derived From Assessment of Circular Gait With a Single Body-Fixed-Sensor: A 5 Year Longitudinal Study

Background and Aim: Development of objective, reliable and easy-to-use methods to obtain progression markers of Parkinson’s disease (PD) is required to evaluate interventions and to advance research in PD. This study aimed to provide quantitative markers of progression in idiopathic PD from the assessment of circular gait (walking in circles) with a single body-fixed inertial sensor placed on the lower back.Methods: The assessments were performed every 6 months over a (up to) 5 years period for 22 patients in early-stage PD, 27 patients in middle-stage PD and 25 healthy controls (HC). Longitudinal changes of 24 gait features extracted from accelerometry were compared between PD groups and HCs with generalized estimating equations (GEE) analysis, accounting for gait speed, age and levodopa medication state confounders when required.Results: Five gait features indicated progressive worsening in early stages of PD: number of steps, total duration and harmonic ratios calculated from vertical (VT), medio-lateral (ML), and anterior-posterior (AP) accelerations. For middle stages of PD, three gait features were identified as potential progression markers: stride time variability, and stride regularity from VT and AP acceleration.Conclusion: Faster progressive worsening of gait features in early and middle stages of PD relative to healthy controls over 5 years confirmed the potential of accelerometry-based assessments as quantitative progression markers in early and middle stages of the disease. The difference in significant parameters between both PD groups suggests that distinct domains of gait deteriorate in these PD stages. We conclude that instrumented circular walking assessment is a practical and useful tool in the assessment of PD progression that may have relevant potential to be implemented in clinical trials and even clinical routine, particularly in a developing digital era

Dual vs. Single Tasking During Circular Walking: What Better Reflects Progression in Parkinson's Disease?

Background and Aim: Reliable, valid and sensitive measures of dual-task-associated impairments in patients with Parkinson's disease (PD) may reveal progressive deficits unnoticed under single-task walking. The aim of this study was to quantitatively identify markers of progressive gait deficits in idiopathic PD while walking over a circular trajectory condition in single-task walking and in different dual-task conditions: (1) circular walking while checking boxes on a paper sheet as fast as possible and (2) circular walking while performing subtraction of 7 as fast as possible. In addition, we aimed to study the added value of dual-tasking assessment over single (circular) walking task assessment in the study of PD progression.Methods: The assessments were performed every 6 months over a (up to) 5 years period for 22 patients in early-stage PD, 27 patients in middle-stage PD and 25 healthy controls (HC). Longitudinal changes of 27 gait features extracted from accelerometry were compared between PD groups and HCs using generalized estimating equations analysis, accounting for gait speed, age, and levodopa medication state confounders when required. In addition, dual-task-interference with gait and cognitive performance was assessed, as well as their combination.Results: The results support the validity and robustness of some of the gait features already identified in our previous work as progression markers of the disease in single-task circular walking. However, fewer gait features from dual-task than from single-task assessments were identified as markers of progression in PD. Moreover, we did not clearly identify progressive worsening of dual-task-interference in patients with PD, although some group differences between early and middle stages of PD vs. the control group were observed for dual-task interference with the gait task and with the concurrent tasks.Conclusions: Overall, the results showed that dual-tasking did not have added value in the study of PD progression from circular gait assessments. Our analyses suggest that, while single-task walking might be sensitive enough, dual-tasking may introduce additional (error) variance to the data and may represent complex composite measures of cognitive and motor performance