Biomedical subjects

H A Middelkoop

Publications and source records attributed to H A Middelkoop.

25 records · Page 2Linked to original sources

PubMed1993

Where to record motor activity: an evaluation of commonly used sites of placement for activity monitors.

The aim of this study was to evaluate the role of the site of attachment of activity monitors. We compared mean diurnal and nocturnal motor activity measures as well as the daily pattern of motor activity of dominant and non-dominant wrist recordings over 5 successive days of 10 healthy right-handed and 10 left-handed subjects. In a second study we evaluated the relationship between truncal motor activity and wrist motor activity. No differences emerged between the diurnal and nocturnal measures as well as the diurnal activity pattern of the dominant and the non-dominant wrist. Additionally, no differences were found in relation to handedness. Our results show that it is inaccurate to regard wrist motor activity measurements as representative of an invariable percentage of truncal motor activity; the relation between the measurements of these two recording sites varies across the daytime period. During the nocturnal period bilateral wrist motor activity occurred frequently in absence of truncal motor activity. The reverse situation, however, may occur sporadically. This finding most likely reflects that integrated generalized movements like postural shifts are measured at all recording sites, while the small movements that occur at the distal extremities are predominantly recorded by wrist-worn monitors. In conclusion, it is apparent that for both diurnal and nocturnal studies on the assessment of motor activity, either wrist can be chosen as the recording site. Across the diurnal period the relation between motor activity recorded at the wrist and waist is subject to considerable variability.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

PubMed1993

Ambulatory activity monitoring during sleep: an evaluation of internight and intrasubject variability in healthy persons aged 50-98 years.

The aim of this study was to assess the internight and intrasubject variability of nocturnal activity and immobility measures of 99 healthy subjects aged 50-98 years. Motor activity was recorded at home during 6 successive nights with a wrist-worn activity monitor. The occurrence of suprathreshold motor activity was recorded over 15-second epochs. For each subject, six mean measures reflecting activity or immobility during sleep and their coefficient of variation were calculated. Our results revealed no first-night effect or day-of-week effect of the activity and immobility measures over the 6 nights across all subjects. On the other hand, for all nocturnal activity and immobility measures, a considerable intrasubject variability across the 6 nights was found. Females had a greater intrasubject variability of the mean duration of immobility periods and the movement index than males. The intrasubject variability of all nocturnal activity and immobility measures across the successive age groups remains stable. These findings emphasize that although a first-night effect may be lacking, the intrasubject variability of activity and immobility measures across several nights may still be considerable.

Aged↗

PubMed1993

Nocturnal activity and immobility across aging (50-98 years) in healthy persons.

OBJECTIVE: To measure the influence of age on measures of nocturnal activity and immobility in 100 healthy subjects aged 50 to 98 years. DESIGN: Cross-sectional study. SETTING: Urban population in Leiden. Recordings were performed at home while the subjects maintained their habitual 24-hour pattern of activities. PARTICIPANTS: 100 subjects without a history of major medical disorders and a normal neurological examination and performance-oriented assessment of gait (Tinetti). MEASUREMENTS: Motor activity was recorded during six successive nights with a wrist-worn activity monitor. The occurrence of supra-threshold motor activity was recorded over 15-second epochs. A questionnaire was used to evaluate sleep habits and the occurrence of sleep disturbances. Four mean measures reflecting activity or immobility during the nocturnal period were calculated for each subject. RESULTS: Only one out of four measures, (ie, the nocturnal proportion of time with movement, increased with age for females. For males, no age effects emerged. The mean duration of nocturnal immobility periods was higher in females than in males. Also, for females, the use of hypnotics increased with successive decades. Sex and the use of hypnotics were significantly related to the mean duration of immobility periods. CONCLUSION: If care is taken not to confound aging with illness, measures of nocturnal activity and immobility reveal only marginal effects of aging.

Activities of Daily Living↗

PubMed1993

Assessment of response fluctuations in Parkinson's disease by ambulatory wrist activity monitoring.

The aim of this study was to examine the influence of response fluctuations with dyskinesia on the 24-h motor activity pattern and measures of diurnal and nocturnal activity and immobility. Motor activity was recorded during 5 successive days in 5 patients with advanced Parkinson's disease (PD) suffering from severe response fluctuations with dyskinesia, as well as in 10 PD patients with a stable levodopa response and 10 healthy subjects. The 24-h motor activity pattern of the patients with response fluctuations provides insight into the relationship between the therapeutic regimen and 1) the frequency and duration of "on" and "off" periods, 2) the severity of the dyskinesias, and 3) the degree of sleep disruption. In accordance with the severity of their motor fluctuations, patients with response fluctuations showed a large intra- and interindividual variability of diurnal motor activity measures. Overall, the nocturnal motor activity measures in the patients with response fluctuations indicated a severely disturbed sleep when compared with the two control groups. Factors as simplicity and the potential to record unrestrained motor activity for several days continuously in all settings, make activity monitoring a welcomed acquisition in the assessment of response fluctuations in PD.

Adult↗

PubMed1993

Diurnal effects of motor activity and fatigue in Parkinson's disease.

Wrist motor activity was monitored continuously in 65 patients with Parkinson's disease (PD) to assess the influence of disease severity and excessive fatigue on the diurnal motor activity pattern. Mildly or moderately affected PD patients had a similar diurnal pattern to that of 68 healthy controls, with a late morning peak; however, mean levels of motor activity were lower. The most severely affected patients showed an overall flattened diurnal pattern. Results refute the existence of end of day deterioration, but instead suggest a "depressed morning start" in the most severely affected patients with PD. Excessive fatigue was not reported at a particular time of day and did not influence the diurnal motor activity pattern.

Adult↗

PubMed1991

A new approach in the assessment of motor activity in Parkinson's disease.

Motor activity was recorded continuously with a wrist-worn activity monitor for almost six days in nine patients with different predominant manifestations of Parkinson's disease and 10 normal subjects. The indices of diurnal motor activity decreased with the progressive worsening of hypokinesia and rigidity. With this monitor and a simple diary it was possible to determine the contribution of a moderate resting tremor and choreiform dyskinesias to the motor activity level, and to monitor their variability.

Adult↗

PubMedDate not supplied

Long-term ambulatory monitoring of urine leakage in the elderly: an evaluation of the validity and clinical applicability of thermistor signalling.

This study evaluated the validity and applicability of a low-cost Urine Leakage Recording Device (ULRD) in a geriatric setting. The ULRD consisted of a thermistor, connected to a portable, digital datalogger. The thermistor was positioned on a commercially available adult diaper. Five healthy females were instructed to void urine in seven behavioural conditions comprising general motor activity patterns of the average, psychogeriatric elderly in-patient. Voids were verbally indicated by the subjects and concomitantly recorded by the ULRD and the observer. After comparing the ULRD records--scored by three independent assessors--with the subjects' reports, on average (SD) 5.3 (0.6) of a total of 10 voids were classified correctly, whereas 9.3 (1.3) false positive events were indicated. None of the subjects reported any inconvenience as a result of the recording procedure. Although the ULRD is easily applicable, we conclude that it seems to be of little value in its present form as a method for long-term ambulatory monitoring of urine leakage.

Aged↗