Assessment of cerebrospinal fluid outflow conductance using constant-pressure infusion--a method with real time estimation of reliability.


:The outflow conductance (C(out)) of the cerebrospinal fluid (CSF) system is a parameter considered to be predictive in selection for hydrocephalus surgery. C(out) can be determined through an infusion test. A new apparatus for performing infusion tests in a standardized and automated way was developed. The objective was to evaluate repetitiveness as well as to propose and evaluate a method for real time estimation of the reliability of individual C(out) investigations. Repeated investigations were performed on an experimental model simulating the CSF system, and on 14 patients with hydrocephalus. DeltaC(out), calculated as the 95% confidence interval of C(out), was introduced as an estimate of the reliability of individual C(out) investigations. On the model, no significant difference was found between DeltaC(out) and the actual C(out) variation in repeated investigations (p = 0.135). The correlation between the first and the second patient investigation was high (R = 0.99, p < 0.05), although there was a significant difference between the investigations (p < 0.05). The standard deviation of difference was 2.60 microl (s kPa)(-1). The repetitiveness of C(out) with the new apparatus was high, and DeltaC(out) reflected the reliability of each investigation. This feature has to be taken into account in every individual case, before making a decision or performing research based on measurements of C(out) in the future.


Physiol Meas


Andersson N,Malm J,Bäcklund T,Eklund A




Has Abstract


2005-12-01 00:00:00














  • Pulmonary perfusion measured by means of electrical impedance tomography.

    abstract::Electrical impedance tomography (EIT) is a recent imaging technique based on electrical impedance, offering the possibility of measuring pulmonary perfusion. In the present study the influence of several pulmonary haemodynamical parameters on the EIT signal were investigated. First, the influence on the systolic wave ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Vonk Noordegraaf A,Kunst PW,Janse A,Marcus JT,Postmus PE,Faes TJ,de Vries PM

    更新日期:1998-05-01 00:00:00

  • Restoration of the electrocardiogram during mechanical cardiopulmonary resuscitation.

    abstract:OBJECTIVE:An artefact-free electrocardiogram (ECG) is essential during cardiac arrest to decide therapy such as defibrillation. Mechanical cardiopulmonary resuscitation (CPR) devices cause movement artefacts that alter the ECG. This study analyzes the effectiveness of mechanical CPR artefact suppression filters to rest...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Isasi I,Irusta U,Aramendi E,Idris AH,Sörnmo L

    更新日期:2020-11-06 00:00:00

  • Wavelet-based real-time calculation of multiple physiological parameters on an embedded platform.

    abstract:OBJECTIVE:This paper aims to present how physiological signals can be processed based on wavelet decomposition to calculate multiple physiological parameters in real-time on an embedded platform. APPROACH:An ECG and PPG are decomposed to the appropriate scale based on a quadratic spline wavelet base in order to obtain...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Tang M,Xia P,He Z,Zhao Z,Chen X,Yang T,Zhang Z,Zhan Q,Li X,Fang Z

    更新日期:2020-03-06 00:00:00

  • Detection of acute periodontal pain from physiological signals.

    abstract:OBJECTIVE:To investigate the feasibility of the detection of brief orofacial pain sensations from easily recordable physiological signals by means of machine learning techniques. APPROACH:A total of 47 subjects underwent periodontal probing and indicated each instance of pain perception by means of a push button. Simu...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Teichmann D,Klopp J,Hallmann A,Schuett K,Wolfart S,Teichmann M

    更新日期:2018-09-27 00:00:00

  • The feasibility of transoesophageal bioimpedance measurements for the detection of heart graft rejection.

    abstract::Previous studies demonstrate that it is possible to evaluate a heart graft rejection condition using a bioimpedance technique by means of an intracavitary catheter. We propose to use a less invasive technique consisting in the use of a transoesophageal catheter and two standard ECG electrodes on the thorax. The aim of...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Giovinazzo G,Ribas N,Cinca J,Rosell-Ferrer J

    更新日期:2011-07-01 00:00:00

  • Evaluation of an EIT reconstruction algorithm using finite difference human thorax models as phantoms.

    abstract::A finite difference model of the human thorax with 113,400 control volumes (nodes) based on ECG gated MRI images was used to evaluate the Sheffield DAS-01P EIT system. Sixteen simulated electrode positions equally spaced around the thorax model at approximately the fourth intercostals space level were selected. Pairs ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Patterson RP,Zhang J

    更新日期:2003-05-01 00:00:00

  • Transthoracic electrical impedance during external defibrillation: comparison of measured and modelled waveforms.

    abstract::The transthoracic electrical impedance is an important defibrillation parameter, affecting the defibrillating current amplitude and energy, and therefore the defibrillation efficiency. A close relationship between transthoracic impedance and defibrillation success rate was observed. Pre-shock measurements (using low a...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Al Hatib F,Trendafilova E,Daskalov I

    更新日期:2000-02-01 00:00:00

  • Empirical mode decomposition analysis of HRV data from patients undergoing local anaesthesia (brachial plexus block).

    abstract::Spectral analysis of heart rate variability (HRV) is used for the assessment of cardiovascular autonomic control. In this study, a data-driven adaptive technique called empirical mode decomposition (EMD) and the associated Hilbert spectrum has been used to evaluate the effect of local anaesthesia on HRV parameters in ...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Shafqat K,Pal SK,Kumari S,Kyriacou PA

    更新日期:2011-04-01 00:00:00

  • Value of simulated body surface potential maps as templates in localizing sites of ectopic activation for radiofrequency ablation.

    abstract::Body surface potential maps recorded during catheter pace mapping can facilitate the localization of the site of origin of ventricular tachycardia. In this study, we investigated the value of a realistic computer model of the human ventricular myocardium in generating body surface potential maps as templates for ident...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Hren R,Horácek BM

    更新日期:1997-11-01 00:00:00

  • A multi-frequency EIT system design based on telecommunication signal processors.

    abstract::A multi-frequency electrical impedance tomography system for cardiopulmonary monitoring has been designed with specialized digital signal processors developed primarily for the telecommunications sector. The system consists of two modules: a scan-head and a base-station. The scan-head, located close to the patient's t...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Robitaille N,Guardo R,Maurice I,Hartinger AE,Gagnon H

    更新日期:2009-06-01 00:00:00

  • Coordinated FA-MS and SIFT-MS analyses of breath following ingestion of D2O and ethanol: total body water, dispersal kinetics and ethanol metabolism.

    abstract::A coordinated study of the dispersal of water between the various body compartments (stomach and gut, blood stream and tissue) and the similar dispersal kinetics of ethanol and its metabolism has been carried out involving two healthy volunteers using flowing afterglow mass spectrometry, FA-MS, and selected ion flow t...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Spanel P,Wang T,Smith D

    更新日期:2005-08-01 00:00:00

  • Inductive plethysmography components analysis and improved non-invasive postoperative apnoea monitoring.

    abstract::Twenty-nine patients were monitored overnight for breathing distress patterns during postoperative analgesia. Nasal flow apnoea monitoring and pulse oximetry data were recorded at 50 Hz. Respiratory inductive plethysmography (RIP) tracked tidal volume (TV) thoracoabdominal motion, and supplemented the flow monitoring ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Millard RK

    更新日期:1999-05-01 00:00:00

  • Cardiac eigen imaging: a novel method to isolate cardiac activity in thoracic electrical impedance tomography.

    abstract:OBJECTIVE:As the global burden of cardiovascular disease increases, proactive cardiovascular healthcare by means of accurate, precise, continuous, and non-invasive monitoring is becoming crucial. However, no current device is able to provide cardiac hemodynamic monitoring with the aforementioned criterion. Electrical i...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Arshad SH,Murphy EK,Callahan JM,DeVries JT,Odame KM,Halter RJ

    更新日期:2020-10-06 00:00:00

  • A novel LabVIEW-based multi-channel non-invasive abdominal maternal-fetal electrocardiogram signal generator.

    abstract::This paper describes the design, construction, and testing of a multi-channel fetal electrocardiogram (fECG) signal generator based on LabVIEW. Special attention is paid to the fetal heart development in relation to the fetus' anatomy, physiology, and pathology. The non-invasive signal generator enables many parameter...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Martinek R,Kelnar M,Koudelka P,Vanus J,Bilik P,Janku P,Nazeran H,Zidek J

    更新日期:2016-02-01 00:00:00

  • Short-term studies of heart rate variability: comparison of two methods for recording.

    abstract::Heart rate variability (HRV) is often analysed using short-term studies. Our objective was to compare two of them in a group of diabetic patients (reduced HRV) and in a control group. From the same 10 min surface electrocardiogram (ECG) two recordings were obtained. In one of them the whole signal was acquired through...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Migliaro ER,Canetti R,Contreras P,Hakas M,Eirea G,Machado A

    更新日期:2004-12-01 00:00:00

  • Daily physical activity patterns from hip- and wrist-worn accelerometers.

    abstract::Accelerometer wear location may influence physical activity estimates. This study investigates this relationship through the examination of activity patterns throughout the day. Participants from the aging research evaluating accelerometry (AREA) study (n men  =  37, n women  =  47, mean age (SD)  =  78.9 (5.5) years)...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Shiroma EJ,Schepps MA,Harezlak J,Chen KY,Matthews CE,Koster A,Caserotti P,Glynn NW,Harris TB

    更新日期:2016-10-01 00:00:00

  • In vivo bioimpedance changes during haemorrhagic and ischaemic stroke in rats: towards 3D stroke imaging using electrical impedance tomography.

    abstract::Electrical impedance tomography (EIT) could be used as a portable non-invasive means to image the development of ischaemic stroke or haemorrhage. The purpose of this study was to examine if this was possible using time difference imaging, in the anesthetised rat using 40 spring-loaded scalp electrodes with applied con...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Dowrick T,Blochet C,Holder D

    更新日期:2016-06-01 00:00:00

  • Infrared thermography for indirect assessment of activation of brown adipose tissue in lean and obese male subjects.

    abstract::Brown adipose tissue (BAT) plays a key role in adaptive thermogenesis in mammals, and it has recently been considered as an attractive therapeutic target for tackling human obesity by increasing energy expenditure. Thermal imaging using infrared thermography (IRT) has emerged as a potential safe, rapid and inexpensive...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: El Hadi H,Frascati A,Granzotto M,Silvestrin V,Ferlini E,Vettor R,Rossato M

    更新日期:2016-12-01 00:00:00

  • Direct EIT Jacobian calculations for conductivity change and electrode movement.

    abstract::Electrical impedance tomography (EIT) is very sensitive to deformations of the medium boundary shape. For lung imaging, breathing and changes in posture move the electrodes and change the chest shape, resulting in image artefacts. Several approaches have been proposed to improve the reconstructed images; most methods ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Gómez-Laberge C,Adler A

    更新日期:2008-06-01 00:00:00

  • Early prediction of unexplained syncope by support vector machines.

    abstract::The goal of the present study was to develop and evaluate a new method for the prediction of unexplained syncope occurrences. Diagnosis of syncope is currently based on the reproduction of symptoms in combination with hypotension and bradycardia induced by a 45 min 60-70 degrees head-upright tilt test (HUTT). The main...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Schang D,Feuilloy M,Plantier G,Fortrat JO,Nicolas P

    更新日期:2007-02-01 00:00:00

  • The physiological impact of the nonlinearity of arterial elasticity in the ambulatory arterial stiffness index.

    abstract::The ambulatory arterial stiffness index (AASI) is claimed to be a new estimator for arterial rigidity. It was recently defined as one minus the slope of the linear regression of systolic to diastolic ambulatory pressure during 24 h. Although several reports testify its clinical relevance, the explanation of how this n...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Craiem D,Graf S,Salvucci F,Chironi G,Megnien JL,Simon A,Armentano RL

    更新日期:2010-07-01 00:00:00

  • A comb filter based signal processing method to effectively reduce motion artifacts from photoplethysmographic signals.

    abstract::A photoplethysmographic (PPG) signal can provide very useful information about a subject's cardiovascular status. Motion artifacts (MAs), which usually deteriorate the waveform of a PPG signal, severely obstruct its applications in the clinical diagnosis and healthcare area. To reduce the MAs from a PPG signal, in the...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Peng F,Liu H,Wang W

    更新日期:2015-10-01 00:00:00

  • Wearable sensors for patient-specific boundary shape estimation to improve the forward model for electrical impedance tomography (EIT) of neonatal lung function.

    abstract::Electrical impedance tomography (EIT) could be significantly advantageous to continuous monitoring of lung development in newborn and, in particular, preterm infants as it is non-invasive and safe to use within the intensive care unit. It has been demonstrated that accurate boundary form of the forward model is import...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Khor JM,Tizzard A,Demosthenous A,Bayford R

    更新日期:2014-06-01 00:00:00

  • Measuring dissimilarity between respiratory effort signals based on uniform scaling for sleep staging.

    abstract::Polysomnography (PSG) has been extensively studied for sleep staging, where sleep stages are usually classified as wake, rapid-eye-movement (REM) sleep, or non-REM (NREM) sleep (including light and deep sleep). Respiratory information has been proven to correlate with autonomic nervous activity that is related to slee...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Long X,Yang J,Weysen T,Haakma R,Foussier J,Fonseca P,Aarts RM

    更新日期:2014-12-01 00:00:00

  • Continuous estimates of dynamic cerebral autoregulation: influence of non-invasive arterial blood pressure measurements.

    abstract::Temporal variability of parameters which describe dynamic cerebral autoregulation (CA), usually quantified by the short-term relationship between arterial blood pressure (BP) and cerebral blood flow velocity (CBFV), could result from continuous adjustments in physiological regulatory mechanisms or could be the result ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Panerai RB,Sammons EL,Smith SM,Rathbone WE,Bentley S,Potter JF,Samani NJ

    更新日期:2008-04-01 00:00:00

  • A portable device with low-power consumption for monitoring mouse vital signs during in vivo photoacoustic imaging and photothermal therapy.

    abstract:OBJECTIVE:The aim of this study was to monitor the physiological changes and cytotoxic effects of exogenous contrast agents during photoacoustic imaging (PAI) and photothermal therapy (PTT). In this paper, a low-power telemetric device for mouse vital signs monitoring was designed and demonstrated. APPROACH:The power ...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Phan DT,Phan TTV,Bui NT,Park S,Choi J,Oh J

    更新日期:2021-01-01 00:00:00

  • Contactless impedance measurement by magnetic induction--a possible method for investigation of brain impedance.

    abstract::Using a primary coil that induces eddy currents in a volume conductor, and a pair of secondary coils configured to form a differential transformer, it is possible to measure the conductivity of a volume conductor by the magnetic fields of the induced eddy currents. This method is especially favourable for measuring im...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Netz J,Forner E,Haagemann S

    更新日期:1993-11-01 00:00:00

  • Effect of lower body negative pressure and gravity on regional lung ventilation determined by EIT.

    abstract::The aim of our study was to check the effect of varying blood volume in the chest and gravity on the distribution of ventilation and aeration in the lungs. The change in intrathoracic blood volume was elicited by application of lower body negative pressure (LBNP) of -50 cmH2O. The variation of gravity in terms of hypo...

    journal_title:Physiological measurement

    pub_type: 临床试验,杂志文章


    authors: Frerichs I,Bodenstein M,Dudykevych T,Hinz J,Hahn G,Hellige G

    更新日期:2005-04-01 00:00:00

  • A CT perfusion based model predicts outcome in wake-up stroke patients treated with recombinant tissue plasminogen activator.

    abstract:OBJECTIVE:Advanced neuroimaging has proved to be pivotal in the management of acute ischemic stroke. The use of CT perfusion (CTP) core and penumbra parameters to predict the outcome in wake-up stroke (WUS) patients in everyday clinical scenarios has not yet been investigated. The aim of our study was to investigate th...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Ajčević M,Furlanis G,Stella AB,Cillotto T,Caruso P,Ridolfi M,Lugnan C,Miladinović A,Ukmar M,Cova MA,Accardo A,Manganotti P,Naccarato M

    更新日期:2020-08-11 00:00:00

  • A comparative study of several exciting magnetic fields for induced current EIT.

    abstract::In this study, the selection of coil configuration parameters (coil radius and coil centre shift) for induced current EIT using circular coils is investigated. An alternative coil configuration is suggested, which produces approximately linear (spatially) magnetic fields in order to strengthen the currents in the cent...

    journal_title:Physiological measurement

    pub_type: 杂志文章


    authors: Gençer NG,Ider YZ

    更新日期:1994-05-01 00:00:00