Background: This article describes the design of an intervention study that focuses on whether an... more Background: This article describes the design of an intervention study that focuses on whether and to what degree culturally competent social robots can improve health and well-being related outcomes among older adults residing long-term care homes. The trial forms the final stage of the international, multidisciplinary CARESSES project aimed at designing, developing and evaluating culturally competent robots that can assist older people according to the culture of the individual they are supporting. The importance of cultural competence has been demonstrated in previous nursing literature to be key towards improving health outcomes among patients. Method: This study employed a mixed-method, single-blind, parallel-group controlled before-and-after experimental trial design that took place in England and Japan. It aimed to recruit 45 residents of long-term care homes aged ≥65 years, possess sufficient cognitive and physical health and who self-identify with the English, Indian or Japanese culture (n = 15 each). Participants were allocated to either the experimental group, control group 1 or control group 2 (all n = 15). Those allocated to the experimental group or control group 1 received a Pepper robot programmed with the CARESSES culturally competent artificial intelligence (experimental group) or a limited version of this software (control group 1) for 18 h across 2 weeks. Participants in control group 2 did not receive a robot and continued to receive care as usual. Participants could also nominate their informal carer(s) to participate. Quantitative data collection occurred at baseline, after 1 week of use, and after 2 weeks of use with the latter time-point also including qualitative semi-structured interviews that explored their experience and perceptions further. Quantitative outcomes of interest included perceptions of robotic cultural competence, healthrelated quality of life, loneliness, user satisfaction, attitudes towards robots and caregiver burden.
International journal of environmental research and public health, Jan 27, 2018
Active workstations have been recommended for reducing sedentary behavior in the workplace. It is... more Active workstations have been recommended for reducing sedentary behavior in the workplace. It is important to understand if the use of these workstations has an impact on worker productivity. The aim of this systematic review was to examine the effect of active workstations on workplace productivity and performance. A total of 3303 articles were initially identified by a systematic search and seven articles met eligibility criteria for inclusion. A quality appraisal was conducted to assess risk of bias, confounding, internal and external validity, and reporting. Most of the studies reported cognitive performance as opposed to productivity. Five studies assessed cognitive performance during use of an active workstation, usually in a single session. Sit-stand desks had no detrimental effect on performance, however, some studies with treadmill and cycling workstations identified potential decreases in performance. Many of the studies lacked the power required to achieve statistical si...
Abbreviations: APAP, acetaminophen, T c , core temperature, T sk , skin temperature, COX, cycloox... more Abbreviations: APAP, acetaminophen, T c , core temperature, T sk , skin temperature, COX, cyclooxygenase 2
Frailty and detection of fall risk are major issues in preventive gerontology. A simple tool freq... more Frailty and detection of fall risk are major issues in preventive gerontology. A simple tool frequently used in daily life, a bathroom scale (balance quality tester: BQT), was modified to obtain information on the balance of 84 outpatients consulting at a geriatric clinic. The results computed from the BQT were compared to the values of three geriatric tests that are widely used either to detect a fall risk or frailty (timed get up and go: TUG; 10 m walking speed: WS; walking time: WT; one-leg stand: OS). The BQT calculates four parameters that are then scored and weighted, thus creating an overall indicator of balance quality. Raw data, partial scores and the global score were compared with the results of the three geriatric tests. The WT values had the highest correlation with BQT raw data (r = 0.55), while TUG (r = 0.53) and WS (r = 0.56) had the highest correlation with BQT partial scores. ROC curves for OS cut-off values (4 and 5 s) were produced, with the best results obtained for a 5 s cut-off, both with the partial scores combined using Fisher's combination (specificity 85 %: <0.11, sensitivity 85 %: >0.48), and with the empirical score (specificity 85 %: <7, sensitivity 85 %: >8). A BQT empirical score of less than seven can detect fall risk in a community dwelling population. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Background: The number of frail elderly people is increasing. Unfortunately, the number of caregi... more Background: The number of frail elderly people is increasing. Unfortunately, the number of caregivers is not increasing at the same pace, which affects older people, caregivers and healthcare systems. Because of these developments, self-management is becoming more important in healthcare. To support community-dwelling elderly people in their self-management, a system was developed that monitors their physical functioning. This system provides feedback to elderly people and their caregivers regarding physical indicators of frailty. The feedback is provided to elderly people via the screen of a mobile phone. It is important that elderly people understand the content of the feedback and are able to use the mobile phone properly. If not, it is unlikely that the system can support self-management. Many interactive health technologies that have been developed do not fulfil their promises. An important reason for this is that human and other non-technology issues are not sufficiently taken into consideration during the development process.
The aim of this pilot study was to evaluate the usability of a monitoring system that can monitor... more The aim of this pilot study was to evaluate the usability of a monitoring system that can monitor indicators of physical functioning (weight, balance, grip strength, and physical activity) in community-dwelling elderly people. Monitoring such indicators can identify elderly people who could benefit from (preventive) interventions. The system can also provide feedback to support elderly people in their selfmanagement. A geriatrician invited patients aged 70 years or older to participate in the pilot study. Participants rated the usability of the monitoring system after using the system at home for three weeks. Usability was measured on a 7-point scale using an adapted version of the Post-Study System Usability Questionnaire and by logging errors that occurred in a diary. Six participants between 79 and 83 years old were included and four of them completed the pilot study. The mean usability score was 5.2 (SD .90) and scores ranged from 3.8 to 6.2. The participants were mostly positive about the usability of the monitoring system but some improvements have to be made before the system can be implemented and evaluated on a larger scale.
... Then, define: Nm Bm (r)=(N-mT1YJ K ir)(8) /= i Similarly, define A"'(r) as (N-ml)~ ... more ... Then, define: Nm Bm (r)=(N-mT1YJ K ir)(8) /= i Similarly, define A"'(r) as (N-ml)~ x times the number of vectors xm+ 1 (y ... Table 1 Ninety-five percent confidence intervals of ApEn and SampEn for control and elderly subjects for AP displacement Entropy Group Approximate Sample ...
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
Réaliser un mouvement à partir d'une posture initiale stable implique que le sujet doit se déséqu... more Réaliser un mouvement à partir d'une posture initiale stable implique que le sujet doit se déséquilibrer. De plus, le sujet étant soumis à la force de gravité qui tend à le faire chuter, il est nécessaire que ce dernier dispose de mécanismes de contrôle de l'équilibre pour évoluer dans son environnement sans chuter. La dégradation de ces mécanismes de contrôle de l'équilibre a été largement mesurée chez le sujet âgé. L'altération de l'équilibre, l'apparition d'un comportement de chute et la perte d'autonomie qui en résultent sont des problèmes majeurs de santé publique. Pour contrecarrer ces problèmes, l'équipe IDéAS de l'UTT s'est spécialisée dans le développement de technologies innovantes pour l'évaluation à domicile de l'autonomie de la personne âgée en évaluant régulièrement la qualité de son équilibre et sa force musculaire de préhension. Ces technologies sont un testeur de qualité de l'équilibre et la Grip-ball.
Proceedings of the Sixth Iasted International Conference on Biomedical Engineering, Feb 6, 2008
Maximal Grip Strength (MGS) is regarded as a good indicator of upper-limb strength or even of the... more Maximal Grip Strength (MGS) is regarded as a good indicator of upper-limb strength or even of the whole neuromuscular system. Two popular dynamometers used for MGS evaluation are the Jamar and the Martin Vigorimeter. The Myogrip is a new digital dynamometer designed for testing very weak patients suffering from various neuromuscular disorders. It offers a sensitivity, precision and accuracy adapted to such a population. The main aim of this study was to compare grip strength assessment using these three dynamometers. Sixty nine healthy undergraduate students volunteered for the study. They were required to exert their MGS using the Jamar, the Vigorimeter and the Myogrip in a random order. After 14 days, 47 subjects participated in a second test. Results show that grip-strength estimates obtained by different measurement devices are strongly correlated. The Myogrip had a significantly better correlation with the Jamar (r=0.93; 95% confidence interval 0.90-0.95) than with the Vigorimeter (0.77; 0.40-0.83). In addition, the Myogrip had high test-retest reliability (ICC: 0.97, 95% confidence interval 0.96-0.98). Test-retest values showed a consistent distribution according to Bland-Altman plots. The circumference of the hand was found to be the most important anthropometric factor in determining MGS, followed by the circumference of the forearm. Predictive regression-based functions with the circumference of the hand alone are given, for dominant and non-dominant sides.
Absiract-Changes in the impedance at the electrode-skin interface of SEMG electrodes on tibialis ... more Absiract-Changes in the impedance at the electrode-skin interface of SEMG electrodes on tibialis anterior were assessed in nine subjects. SEMG signals were recorded using a bipolar electrode configuration that conformed to the SENIAM recommendations for SEMG data collection. Impedance measurements were made between a pair of bipolar electrodes using a custom-built device consisting of a PC and an impedance conversion circuit. The impedance device enabled the . simultaneous application and recording of a waveform constructed of a known combination of sinusoids passed between the two electrodes. SEMG recordings at 10% of each subject's maximal voluntary force during ankle dorsiflexion were made for a 30-s period every 15-min over a two hour period. Impedance was measured immediately before and after each SEMG recording. All subjects gave their written informed consent.
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
L'étude de la posture statique présente un grand intérêt pour l'analyse du déficit du contrôle de... more L'étude de la posture statique présente un grand intérêt pour l'analyse du déficit du contrôle de l'équilibre. Une méthode d'analyse de l'équilibre consiste à utiliser une plate-forme de forces qui permet d'extraire le déplacement du centre de pression (CdP). Les paramètres extraits du CdP s'avèrent comme des variables clés pour surveiller la dégradation de l'équilibre. Cependant, la non pertinence et\ou la redondance de certains d'entre eux rendent difficile une détection efficace d'une dégradation. L'objectif de cet article est l'implémentation d'une méthode de détection à noyau (SVDD) et d'une procédure de sélection des paramètres pertinents capables de détecter une dégradation de l'équilibre. Le critère de sélection choisi est la maximisation de la surface sous la courbe COR.
Background: This article describes the design of an intervention study that focuses on whether an... more Background: This article describes the design of an intervention study that focuses on whether and to what degree culturally competent social robots can improve health and well-being related outcomes among older adults residing long-term care homes. The trial forms the final stage of the international, multidisciplinary CARESSES project aimed at designing, developing and evaluating culturally competent robots that can assist older people according to the culture of the individual they are supporting. The importance of cultural competence has been demonstrated in previous nursing literature to be key towards improving health outcomes among patients. Method: This study employed a mixed-method, single-blind, parallel-group controlled before-and-after experimental trial design that took place in England and Japan. It aimed to recruit 45 residents of long-term care homes aged ≥65 years, possess sufficient cognitive and physical health and who self-identify with the English, Indian or Japanese culture (n = 15 each). Participants were allocated to either the experimental group, control group 1 or control group 2 (all n = 15). Those allocated to the experimental group or control group 1 received a Pepper robot programmed with the CARESSES culturally competent artificial intelligence (experimental group) or a limited version of this software (control group 1) for 18 h across 2 weeks. Participants in control group 2 did not receive a robot and continued to receive care as usual. Participants could also nominate their informal carer(s) to participate. Quantitative data collection occurred at baseline, after 1 week of use, and after 2 weeks of use with the latter time-point also including qualitative semi-structured interviews that explored their experience and perceptions further. Quantitative outcomes of interest included perceptions of robotic cultural competence, healthrelated quality of life, loneliness, user satisfaction, attitudes towards robots and caregiver burden.
International journal of environmental research and public health, Jan 27, 2018
Active workstations have been recommended for reducing sedentary behavior in the workplace. It is... more Active workstations have been recommended for reducing sedentary behavior in the workplace. It is important to understand if the use of these workstations has an impact on worker productivity. The aim of this systematic review was to examine the effect of active workstations on workplace productivity and performance. A total of 3303 articles were initially identified by a systematic search and seven articles met eligibility criteria for inclusion. A quality appraisal was conducted to assess risk of bias, confounding, internal and external validity, and reporting. Most of the studies reported cognitive performance as opposed to productivity. Five studies assessed cognitive performance during use of an active workstation, usually in a single session. Sit-stand desks had no detrimental effect on performance, however, some studies with treadmill and cycling workstations identified potential decreases in performance. Many of the studies lacked the power required to achieve statistical si...
Abbreviations: APAP, acetaminophen, T c , core temperature, T sk , skin temperature, COX, cycloox... more Abbreviations: APAP, acetaminophen, T c , core temperature, T sk , skin temperature, COX, cyclooxygenase 2
Frailty and detection of fall risk are major issues in preventive gerontology. A simple tool freq... more Frailty and detection of fall risk are major issues in preventive gerontology. A simple tool frequently used in daily life, a bathroom scale (balance quality tester: BQT), was modified to obtain information on the balance of 84 outpatients consulting at a geriatric clinic. The results computed from the BQT were compared to the values of three geriatric tests that are widely used either to detect a fall risk or frailty (timed get up and go: TUG; 10 m walking speed: WS; walking time: WT; one-leg stand: OS). The BQT calculates four parameters that are then scored and weighted, thus creating an overall indicator of balance quality. Raw data, partial scores and the global score were compared with the results of the three geriatric tests. The WT values had the highest correlation with BQT raw data (r = 0.55), while TUG (r = 0.53) and WS (r = 0.56) had the highest correlation with BQT partial scores. ROC curves for OS cut-off values (4 and 5 s) were produced, with the best results obtained for a 5 s cut-off, both with the partial scores combined using Fisher's combination (specificity 85 %: <0.11, sensitivity 85 %: >0.48), and with the empirical score (specificity 85 %: <7, sensitivity 85 %: >8). A BQT empirical score of less than seven can detect fall risk in a community dwelling population. which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.
Background: The number of frail elderly people is increasing. Unfortunately, the number of caregi... more Background: The number of frail elderly people is increasing. Unfortunately, the number of caregivers is not increasing at the same pace, which affects older people, caregivers and healthcare systems. Because of these developments, self-management is becoming more important in healthcare. To support community-dwelling elderly people in their self-management, a system was developed that monitors their physical functioning. This system provides feedback to elderly people and their caregivers regarding physical indicators of frailty. The feedback is provided to elderly people via the screen of a mobile phone. It is important that elderly people understand the content of the feedback and are able to use the mobile phone properly. If not, it is unlikely that the system can support self-management. Many interactive health technologies that have been developed do not fulfil their promises. An important reason for this is that human and other non-technology issues are not sufficiently taken into consideration during the development process.
The aim of this pilot study was to evaluate the usability of a monitoring system that can monitor... more The aim of this pilot study was to evaluate the usability of a monitoring system that can monitor indicators of physical functioning (weight, balance, grip strength, and physical activity) in community-dwelling elderly people. Monitoring such indicators can identify elderly people who could benefit from (preventive) interventions. The system can also provide feedback to support elderly people in their selfmanagement. A geriatrician invited patients aged 70 years or older to participate in the pilot study. Participants rated the usability of the monitoring system after using the system at home for three weeks. Usability was measured on a 7-point scale using an adapted version of the Post-Study System Usability Questionnaire and by logging errors that occurred in a diary. Six participants between 79 and 83 years old were included and four of them completed the pilot study. The mean usability score was 5.2 (SD .90) and scores ranged from 3.8 to 6.2. The participants were mostly positive about the usability of the monitoring system but some improvements have to be made before the system can be implemented and evaluated on a larger scale.
... Then, define: Nm Bm (r)=(N-mT1YJ K ir)(8) /= i Similarly, define A"'(r) as (N-ml)~ ... more ... Then, define: Nm Bm (r)=(N-mT1YJ K ir)(8) /= i Similarly, define A"'(r) as (N-ml)~ x times the number of vectors xm+ 1 (y ... Table 1 Ninety-five percent confidence intervals of ApEn and SampEn for control and elderly subjects for AP displacement Entropy Group Approximate Sample ...
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
Réaliser un mouvement à partir d'une posture initiale stable implique que le sujet doit se déséqu... more Réaliser un mouvement à partir d'une posture initiale stable implique que le sujet doit se déséquilibrer. De plus, le sujet étant soumis à la force de gravité qui tend à le faire chuter, il est nécessaire que ce dernier dispose de mécanismes de contrôle de l'équilibre pour évoluer dans son environnement sans chuter. La dégradation de ces mécanismes de contrôle de l'équilibre a été largement mesurée chez le sujet âgé. L'altération de l'équilibre, l'apparition d'un comportement de chute et la perte d'autonomie qui en résultent sont des problèmes majeurs de santé publique. Pour contrecarrer ces problèmes, l'équipe IDéAS de l'UTT s'est spécialisée dans le développement de technologies innovantes pour l'évaluation à domicile de l'autonomie de la personne âgée en évaluant régulièrement la qualité de son équilibre et sa force musculaire de préhension. Ces technologies sont un testeur de qualité de l'équilibre et la Grip-ball.
Proceedings of the Sixth Iasted International Conference on Biomedical Engineering, Feb 6, 2008
Maximal Grip Strength (MGS) is regarded as a good indicator of upper-limb strength or even of the... more Maximal Grip Strength (MGS) is regarded as a good indicator of upper-limb strength or even of the whole neuromuscular system. Two popular dynamometers used for MGS evaluation are the Jamar and the Martin Vigorimeter. The Myogrip is a new digital dynamometer designed for testing very weak patients suffering from various neuromuscular disorders. It offers a sensitivity, precision and accuracy adapted to such a population. The main aim of this study was to compare grip strength assessment using these three dynamometers. Sixty nine healthy undergraduate students volunteered for the study. They were required to exert their MGS using the Jamar, the Vigorimeter and the Myogrip in a random order. After 14 days, 47 subjects participated in a second test. Results show that grip-strength estimates obtained by different measurement devices are strongly correlated. The Myogrip had a significantly better correlation with the Jamar (r=0.93; 95% confidence interval 0.90-0.95) than with the Vigorimeter (0.77; 0.40-0.83). In addition, the Myogrip had high test-retest reliability (ICC: 0.97, 95% confidence interval 0.96-0.98). Test-retest values showed a consistent distribution according to Bland-Altman plots. The circumference of the hand was found to be the most important anthropometric factor in determining MGS, followed by the circumference of the forearm. Predictive regression-based functions with the circumference of the hand alone are given, for dominant and non-dominant sides.
Absiract-Changes in the impedance at the electrode-skin interface of SEMG electrodes on tibialis ... more Absiract-Changes in the impedance at the electrode-skin interface of SEMG electrodes on tibialis anterior were assessed in nine subjects. SEMG signals were recorded using a bipolar electrode configuration that conformed to the SENIAM recommendations for SEMG data collection. Impedance measurements were made between a pair of bipolar electrodes using a custom-built device consisting of a PC and an impedance conversion circuit. The impedance device enabled the . simultaneous application and recording of a waveform constructed of a known combination of sinusoids passed between the two electrodes. SEMG recordings at 10% of each subject's maximal voluntary force during ankle dorsiflexion were made for a 30-s period every 15-min over a two hour period. Impedance was measured immediately before and after each SEMG recording. All subjects gave their written informed consent.
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
Some air forces are concerned with the adequacy of existing pilot selection standards in respect ... more Some air forces are concerned with the adequacy of existing pilot selection standards in respect to pilot strength. Some studies have provided evidence that a large number of pilots may not be able to match the control force levels specified in both military and civilian aircraft design standards. However, both sets of design standards have been based on the subjective comments of test pilots and may not, therefore, be applicable for the majority of pilots. The aim of this study was to quantify aircraft control forces during emergency maneuvers in an Iroquois helicopter and compare these forces with design standards. The examination of muscle activation patterns of pilots during maneuvers, when normalized, can provide additional information on the relative activation levels that pilots are using to produce the aircraft control forces. Six pilots were tested in a UH-1 H Iroquois helicopter. The maneuvers were three engine-out landings and a hydraulics-off landing. The variables recorded were pilot applied forces and EMG activity. Multivariate analysis of variance was used to test for differences between maneuvers. The greatest cyclic and upward collective control forces were observed during constant attitude and variable flare engine-out landings. The greatest downward collective forces were observed during hydraulics-off landing. Greater levels of muscle activation were consistently observed during hydraulics-off landing than during the engine-out landings. Control forces consistently exceeded military design standards for cyclic and collective controls, however muscle activity levels were sub-maximal for all maneuvers. Comparisons between existing aircraft control-force design standards and pilot strength may overestimate the number of pilots who are able to produce sufficient force to fly the aircraft. Despite the high control forces observed, all pilots tested were able to successfully maneuver the helicopter without requiring a maximal muscular effort.
L'étude de la posture statique présente un grand intérêt pour l'analyse du déficit du contrôle de... more L'étude de la posture statique présente un grand intérêt pour l'analyse du déficit du contrôle de l'équilibre. Une méthode d'analyse de l'équilibre consiste à utiliser une plate-forme de forces qui permet d'extraire le déplacement du centre de pression (CdP). Les paramètres extraits du CdP s'avèrent comme des variables clés pour surveiller la dégradation de l'équilibre. Cependant, la non pertinence et\ou la redondance de certains d'entre eux rendent difficile une détection efficace d'une dégradation. L'objectif de cet article est l'implémentation d'une méthode de détection à noyau (SVDD) et d'une procédure de sélection des paramètres pertinents capables de détecter une dégradation de l'équilibre. Le critère de sélection choisi est la maximisation de la surface sous la courbe COR.
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Papers by David Hewson