D. M. Simpson

Publication List Details

Period

1954 - 2008

Number

86

Co-Authors

Optimizing the assessment of autoregulation from black-box models (2008)

Simpson, D.M., Birch, A.A.

Autoregulation mechanisms maintain blood flow approximately stable when blood pressure changes. Impairment in autoregulatory function can be identified by black-box modelling with blood pressure as...

The relationship between upper limb activity and impairment in post-stroke hemiplegia (2008)

Burridge, J.H., Turk, R., Notley, S.V., Pickering, R.M., Simpson, D.M.

Purpose. To investigate the relationship between upper limb impairments and activity limitation. Method. A cross sectional, single assessment observational study in which people with hemiplegia as a...

The relationship between upper limb activity and impairment in post-stroke hemiplegia (2008)

Burridge, J.H., Turk, R., Notley, S.V., Pickering, R.M., Simpson, D.M.

Purpose. To investigate the relationship between upper limb impairments and activity limitation. Method. A cross sectional, single assessment observational study in which people with hemiplegia as a...

Heart-rate and blood-pressure variability during psychophysiological tasks involving speech: influence of respiration (2007)

Beda, A., Jandre, F.C., Phillips, D.I.W., Giannella-Neto, A., Simpson, D.M.

Changes in heart-rate and systolic arterial pressure variability (HRV and SAPV) indexes have been used in psychophysiology to assess autonomic activation, including during tasks involving speech. The...

Optimising the detection of transient evoked potentials using a bootstrap re-sampling technique to provide an objective measure of signal recovery (2007)

Fisher, A.C., Simpson, D.M., Hagan, R.P., Brown, M.C.

Introduction: Most commonly, the estimation of transient evoked potentials such as the ERG, PERG and VEP is by simple ensemble averaging, synchronized by the stimulation signal. This requires three...

Analysis of the quality of wrist movement during a simple tracking task (2007)

Notley, S.V., Turk, R., Pickering, R., Simpson, D.M., Burridge, J.H.

Objective assessment of stroke-patients' ability to control arm movements is vital for evidence-based therapy and progress monitoring. This study compares three different indices to quantify the...

Heart-rate and blood-pressure variability during psychophysiological tasks involving speech: influence of respiration (2007)

Beda, A., Jandre, F.C., Phillips, D.I., Giannella-Neto, A., Simpson, D.M.

Changes in heart-rate and systolic arterial pressure variability (HRV and SAPV) indexes have been used in psychophysiology to assess autonomic activation, including during tasks involving speech. The...

A bootstrap approach to the detection of auditory evoked potentials (2007)

Bell, S.L., Lv, J., Manders, A.J., Simpson, D.M.

Auditory Evoked potentials are often evaluated subjectively (by visual inspection) and considerable differences between interpretations can occur. Objective, automated methods are normally based on...

Size at birth and autonomic function during psychological stress (2007)

Jones, A., Beda, A., Ward, A.M., Osmond, C., Phillips, D.I., Moore, V.M., ...

Small size at birth is associated with exaggerated blood pressure responses to psychological stressors, which increase the risk of developing sustained hypertension in adult life. Explanatory...

Objective selection of signals for assessment of cerebral blood flow autoregulation in neonates (2006)

Ramos, E.G., Simpson, D.M., Panerai, R.B., Nadal, J., Lopes, J.M.A., Evans, D.H.

A number of different system identification techniques have been proposed to assess dynamic cerebral autoregulation in critically ill patients. From these methods, the response to a standard stepwise...

Comments on "Statistical Distribution of the Measure of Coherence" (2006)

Simpson, D.M., Infantosi, A.F.C.

n the letter by Nadarajah and Kotz (2006), the sampling distribution of a new coherence measure proposed by us in 2001 is said to be derived, and programs for computing the moments, percentiles...

Detection of evoked responses by bootstrap methods: new parameters and ROC analysis (2006)

Lv, J., Simpson, D.M., Bell, S.L.

The aim of this work is to describe and evaluate extensions to a bootstrap technique for detecting ABRs. These methods give significance levels (p-values) for: 1) the correlation coefficient between...

Estimation of coherence between blood flow and spontaneous EEG activity in neonates (2005)

Simpson, D.M., Rosas, D.A.B., Infantosi, A.F.C.

Blood flow to the brain responds to changes in neuronal activity and, thus, metabolic demand. In earlier work, we observed correlation between cerebral blood flow and spontaneous electroencephalogram...

Demystifying biomedical signals: A student centred approach to learning signal processing (2005)

Simpson, D.M., De Stefano, A., Allen, R., Lutman, M.E.

The processing and analysis of physiological signals has become firmly established in clinical medicine and biomedical research. Many of the users of this technology however do not come from an...

High spontaneous fluctuation in arterial blood pressure improves the assessment of cerebral autoregulation (2005)

Liu, J., Simpson, D.M., Allen, R.

Cerebral autoregulation maintains a relatively constant blood flow despite changes of blood pressure in the brain. Linear models have been extensively applied to identify this mechanism, using...

A bootstrap approach to testing for an association between bursts in the neonatal EEG and changes in cerebral blood flow (2005)

Simpson, D.M., Polychronaki, G.E., Boylan, G.

In the EEG of normal premature neonates, the Tracé Discontinu pattern is common, consisting of bursts of relatively high amplitude activity, followed by periods of low amplitude. Little is known...

Assessing blood flow control through a bootstrap method (2004)

Simpson, D.M., Panerai, R.B., Ramos, E.G., Lopes, J.M.A., Villar Marinatto, M.N., Nadal, J., ...

In order to assess blood flow control, the relationship between blood pressure and blood flow can be modeled by linear filters. We present a bootstrap method, which allows the statistical analysis of...

Assessing Blood Flow Control Through a Bootstrap Method (2004)

Simpson, D.M., Panerai, R.B., Ramos, E.G., Lopes, J.M.A., Villar, M., Nadal, J., ...

This is the version as published by IEEE and available on the IEEE website http://ieeexplore.ieee.org

Estimation of coherence between cerebral blood flow velocity and EEG activity in newborn babies (2002)

Simpson, D.M., Botero Rosas, D.A., Infantosi, F.C.A.

Blood flow to the brain is normally regulated by control mechanisms, whose failure has been linked to cerebral ischaemia and intracranial haemorrhage. We have been investigating this control in...

Estimation of coherence between cerebral blood flow velocity and EEG activity in newborn babies (2002)

Simpson, D.M., Botero Rosas, D.A., Infantosi, A.F.C.

Introduction: Blood flow to the brain is normally regulated by control mechanisms, whose failure has been linked to cerebral ischaemia and intracranial haemorrhage. We have been investigating this...

Coherence between one random and one periodic signal for measuring the strength of responses in the electro-encephalogram during sensory stimulation (2002)

Infantosi, A.F.C., Simpson, D.M.

Coherence between a pulse train representing periodic stimuli and the EEG has been used in the objective detection of steady-state evoked potentials. This work aimed to quantify the strength of the...

Photic driving in the electroencephalogram of children and adolescents: harmonic structure and relation to the resting state (2001)

Lazarev,V.V., Simpson,D.M., Schubsky,B.M., DeAzevedo,L.C.

In order to identify latent bioelectrical oscillators, 15 normal subjects (aged 9-17 years, 8 males, 7 females) were subjected to intermittent photic stimulation. The EEG amplitude spectra...

Individual frequency profile of photic driving in children and adolescents (2001)

Lazarev, V.V., Simpson, D.M.

In 15 normal subjects, individual "profiles" of the driving reaction to intermittent photic stimulation were calculated in 15 leads, by combining EEG amplitude spectra at 11 fixed frequencies (3-24...

A statistical technique for measuring synchronism between cortical regions in the EEG during rhythmic stimulation (2001)

Infantosi, A.F.C., Simpson, D.M.

The coherence function has been widely applied in quantifying the degree of synchronism between electroencephalogram (EEG) signals obtained from different brain regions. However, when applied to...

Estimation and significance testing of cross-correlation between cerebral blood flow velocity and background electro-encephalograph activity in signals with missing samples (2001)

Simpson, D.M., Infantosi, A.F.C., Botero Rosas, D.A.

Cross-correlation between cerebral blood flow (CBF) and background EEG activity can indicate the integrity of CBF control under changing metabolic demand. The difficulty of obtaining long, continuous...

A statistical technique for measuring synchronism between corticalregions in the EEG during rhythmic stimulation (2001)

Infantosi, A.F.C., Simpson, D.M.

The coherence function has been widely applied in quantifying the degree of synchronism between electroencephalogram (EEG) signals obtained from different brain regions. However, when applied to...

Photic driving in the electroencephalogram of children and adolescents: harmonic structure and relation to the resting state (2001)

Lazarev, V.V., Simpson, D.M., Schubesky, B.M., De Azevedo, L.C.

In order to identify latent bioelectrical oscillators, 15 normal subjects (aged 9-17 years, 8 males, 7 females) were subjected to intermittent photic stimulation. The EEG amplitude spectra...

A parametric approach to measuring cerebral blood flow autoregulation from spontaneous variations in blood pressure (2001)

Simpson, D.M., Panerai, R.B., Evans, D.H., Naylor, A.R.

Autoregulation maintains cerebral blood flow (CBF) almost constant in the face of changes in arterial blood pressure (ABP). Tests for impairment of this process using only spontaneous fluctuations in...

The impact of public assistance factors on the immunization levels of children younger than 2 years.

Suarez, L, Simpson, D M, Smith, D R

OBJECTIVES: This study examined how children's immunization status varied with enrollment in the Women, Infants, and Children (WIC); Aid to Families with Dependent Children (AFDC); food stamp; and...

The impact of public assistance factors on the immunization levels of children younger than 2 years.

Suarez, L, Simpson, D M, Smith, D R

OBJECTIVES: This study examined how children's immunization status varied with enrollment in the Women, Infants, and Children (WIC); Aid to Families with Dependent Children (AFDC); food stamp; and...

Clinical Q fever in Northern Ireland 1962-1989.

Connolly, J. H., Coyle, P. V., Adgey, A. A., O'Neill, H. J., Simpson, D. M.

Q fever was diagnosed in 443 patients in Northern Ireland between 1962 and 1989. From 1986 onwards there was an increase, which peaked in 1989 with 107 cases of whom 47 were infected in Ballycastle,...