Ilias Tachtsidis

Summary

Affiliation: University College London
Country: UK

Publications

  1. pmc Canonical correlation analysis in the study of cerebral and peripheral haemodynamics interrelations with systemic variables in neonates supported on ECMO
    Alexander Caicedo
    Department of Electrical Engineering and IBBT Future Health Department, Katholieke Universiteit Leuven, Leuven, Belgium
    Adv Exp Med Biol 765:23-9. 2013
  2. pmc Functional optical topography analysis using statistical parametric mapping (SPM) methodology with and without physiological confounds
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 662:237-43. 2010
  3. pmc Analysis of the changes in the oxidation of brain tissue cytochrome-c-oxidase in traumatic brain injury patients during hypercapnoea: a broadband NIRS study
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 701:9-14. 2011
  4. pmc A hybrid multi-distance phase and broadband spatially resolved spectrometer and algorithm for resolving absolute concentrations of chromophores in the near-infrared light spectrum
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 662:169-75. 2010
  5. doi request reprint Measurement of frontal lobe functional activation and related systemic effects: a near-infrared spectroscopy investigation
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WC1E 6BT
    Adv Exp Med Biol 614:397-403. 2008
  6. ncbi request reprint Investigation of in vivo measurement of cerebral cytochrome-c-oxidase redox changes using near-infrared spectroscopy in patients with orthostatic hypotension
    I Tachtsidis
    Department of Medical Physics and Bioengineering, Malet Place Engineering Building, University College London, Gower Street, London, UK
    Physiol Meas 28:199-211. 2007
  7. ncbi request reprint Quantification of adult cerebral blood volume using the NIRS tissue oxygenation index
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Shropshire House, 11 20 Capper Street, London
    Adv Exp Med Biol 578:237-43. 2006
  8. doi request reprint Measurement of cerebral tissue oxygenation in young healthy volunteers during acetazolamide provocation: a transcranial Doppler and near-infrared spectroscopy investigation
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WCIE 6BT
    Adv Exp Med Biol 614:389-96. 2008
  9. ncbi request reprint Spectral characteristics of spontaneous oscillations in cerebral haemodynamics are posture dependent
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, University College London, London WC1E 6JA, UK
    Adv Exp Med Biol 540:31-6. 2003
  10. ncbi request reprint Investigation of cerebral haemodynamics by near-infrared spectroscopy in young healthy volunteers reveals posture-dependent spontaneous oscillations
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, University College London, London WC1E 6JA, UK
    Physiol Meas 25:437-45. 2004

Collaborators

Detail Information

Publications65

  1. pmc Canonical correlation analysis in the study of cerebral and peripheral haemodynamics interrelations with systemic variables in neonates supported on ECMO
    Alexander Caicedo
    Department of Electrical Engineering and IBBT Future Health Department, Katholieke Universiteit Leuven, Leuven, Belgium
    Adv Exp Med Biol 765:23-9. 2013
    ....
  2. pmc Functional optical topography analysis using statistical parametric mapping (SPM) methodology with and without physiological confounds
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 662:237-43. 2010
    ..Group analysis using SPM showed significant correlation in a large number of OT channels between HbO(2) and systemic regressors; however no differences in activation areas were seen between the two approaches...
  3. pmc Analysis of the changes in the oxidation of brain tissue cytochrome-c-oxidase in traumatic brain injury patients during hypercapnoea: a broadband NIRS study
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 701:9-14. 2011
    ..Further work using model informed data interpretation may be helpful in understanding the multimodal signals acquired in this heterogeneous patient group...
  4. pmc A hybrid multi-distance phase and broadband spatially resolved spectrometer and algorithm for resolving absolute concentrations of chromophores in the near-infrared light spectrum
    Ilias Tachtsidis
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 662:169-75. 2010
    ..Preliminary results in solid phantoms as well as liquid dynamic homogeneous and inhomogeneous phantoms and in-vivo muscle measurements showed encouraging results...
  5. doi request reprint Measurement of frontal lobe functional activation and related systemic effects: a near-infrared spectroscopy investigation
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WC1E 6BT
    Adv Exp Med Biol 614:397-403. 2008
    ..The [HbO2] and [HHb] signals measured over the frontal region were found to have a varying association with the MBP signal across different volunteers. The effect of these systemic changes on measured NIRS signals must be considered..
  6. ncbi request reprint Investigation of in vivo measurement of cerebral cytochrome-c-oxidase redox changes using near-infrared spectroscopy in patients with orthostatic hypotension
    I Tachtsidis
    Department of Medical Physics and Bioengineering, Malet Place Engineering Building, University College London, Gower Street, London, UK
    Physiol Meas 28:199-211. 2007
    ..Further investigation is required to determine the clinical significance of the changes in [(ox)CCO]...
  7. ncbi request reprint Quantification of adult cerebral blood volume using the NIRS tissue oxygenation index
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Shropshire House, 11 20 Capper Street, London
    Adv Exp Med Biol 578:237-43. 2006
  8. doi request reprint Measurement of cerebral tissue oxygenation in young healthy volunteers during acetazolamide provocation: a transcranial Doppler and near-infrared spectroscopy investigation
    Ilias Tachtsidis
    Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WCIE 6BT
    Adv Exp Med Biol 614:389-96. 2008
    ..This work suggests that using this commercial NIRS instrument with an optode spacing of 5 cm one is able to detect the intracranial changes...
  9. ncbi request reprint Spectral characteristics of spontaneous oscillations in cerebral haemodynamics are posture dependent
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, University College London, London WC1E 6JA, UK
    Adv Exp Med Biol 540:31-6. 2003
  10. ncbi request reprint Investigation of cerebral haemodynamics by near-infrared spectroscopy in young healthy volunteers reveals posture-dependent spontaneous oscillations
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, University College London, London WC1E 6JA, UK
    Physiol Meas 25:437-45. 2004
    ..Oscillatory changes in [O2Hb] and TOI, which may be related to the degree of cerebral sympathetic stimulation, are posture dependent in healthy subjects...
  11. pmc Cytochrome c oxidase response to changes in cerebral oxygen delivery in the adult brain shows higher brain-specificity than haemoglobin
    Christina Kolyva
    Dept of Medical Physics and Bioengineering, University College London, London, UK Electronic address
    Neuroimage 85:234-44. 2014
    ....
  12. pmc Modelling blood flow and metabolism in the piglet brain during hypoxia-ischaemia: simulating brain energetics
    Tracy Moroz
    CoMPLEX, University College London, London, UK
    Adv Exp Med Biol 789:339-44. 2013
    ..However, the simulations do not match the NIRS haemoglobin measurements. The model therefore predicts that further physiological changes must also be taking place if the hypothesis of dead cells is correct. ..
  13. pmc Normobaric hyperoxia does not change optical scattering or pathlength but does increase oxidised cytochrome C oxidase concentration in patients with brain injury
    Arnab Ghosh
    Institute of Neurology, University College London, London, UK
    Adv Exp Med Biol 765:67-72. 2013
    ..These results suggest that the measurement of chromophore concentration in the injured brain is not confounded by changes in optical scattering or pathlength and that NBH induces an increase in cerebral aerobic metabolism...
  14. doi request reprint Cerebral tissue oxygen saturation calculated using low frequency haemoglobin oscillations measured by near infrared spectroscopy in adult ventilated patients
    Terence S Leung
    Department of Medical Physics and Bioengineering, University College London, London, UK
    Adv Exp Med Biol 614:235-44. 2008
    ..This measure of S(osc)O2 may provide a viable, continuous, non invasive, bedside measure of cerebral venous oxygen saturation...
  15. pmc Dependence on NIRS source-detector spacing of cytochrome c oxidase response to hypoxia and hypercapnia in the adult brain
    Christina Kolyva
    Department of Medical Physics and Bioengineering, University College London, London, UK
    Adv Exp Med Biol 789:353-9. 2013
    ..We conclude that the Δ[oxCCO] response to hypoxia and hypercapnia appears to be dependent on penetration depth, possibly reflecting differences between the intra- and extracerebral tissue concentration of cytochrome c oxidase. ..
  16. pmc The effect on cerebral tissue oxygenation index of changes in the concentrations of inspired oxygen and end-tidal carbon dioxide in healthy adult volunteers
    Martin M Tisdall
    Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery, University College London Hospitals, London, UK
    Anesth Analg 109:906-13. 2009
    ..We designed this study to investigate the effect of systemic and intracranial physiological changes on TOI...
  17. ncbi request reprint Investigation of oxygen saturation derived from cardiac pulsations measured on the adult head using NIR spectroscopy
    Terence S Leung
    Department of Medical Physics and Bioengineering, University College London, London, WC1E 6JA, UK
    Adv Exp Med Biol 578:209-15. 2006
  18. ncbi request reprint Measurement of the absolute optical properties and cerebral blood volume of the adult human head with hybrid differential and spatially resolved spectroscopy
    Terence S Leung
    Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Phys Med Biol 51:703-17. 2006
    ..9 +/- 10.0) x 10(-4) mm(-1) and -0.084 +/- 0.266 mm(-1), respectively. The method we describe extends the functionality of the current SRS instrumentation...
  19. doi request reprint Changes in the attenuation of near infrared spectra by the healthy adult brain during hypoxaemia cannot be accounted for solely by changes in the concentrations of oxy- and deoxy-haemoglobin
    Martin M Tisdall
    Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery, Queen Square, London, UK
    Adv Exp Med Biol 614:217-25. 2008
    ..Including [oxCCO] in the algorithm improves its fit quality. These data suggest that changes in cerebral cytochrome c oxidase redox occur during hypoxaemia and that they can be detected using NIRS...
  20. pmc Wavelet cross-correlation to investigate regional variations in cerebral oxygenation in infants supported on extracorporeal membrane oxygenation
    Maria Papademetriou
    Medical Physics and Bioengineering Department, University College London, London, UK
    Adv Exp Med Biol 765:203-9. 2013
    ..Manipulations of ECMO flows are associated with regional changes in cerebral autoregulation which may potentially have an important bearing on clinical outcome...
  21. doi request reprint Multichannel near infrared spectroscopy indicates regional variations in cerebral autoregulation in infants supported on extracorporeal membrane oxygenation
    Maria D Papademetriou
    University College London, Medical Physics and Biomedical Engineering, London, United Kingdom
    J Biomed Opt 17:067008. 2012
    ....
  22. doi request reprint Estimating a modified Grubb's exponent in healthy human brains with near infrared spectroscopy and transcranial Doppler
    Terence S Leung
    Department of Medical Physics and Bioengineering, University College London, London, UK
    Physiol Meas 30:1-12. 2009
    ..Both NIRS and transcranial Doppler techniques are non-invasive and portable, facilitating future studies in other population groups such as brain-injured patients...
  23. pmc Reduction of cytochrome C oxidase during vasovagal hypoxia-ischemia in human adult brain: a case study
    Arnab Ghosh
    Neurocritical Care Unit, University College Hospitals, WC1N 3BG, London, UK
    Adv Exp Med Biol 789:21-7. 2013
    ..This unexpected physiological event provides an unusual example of a severe reduction in cerebral oxygen delivery and is the first report correlating change in clinical status with changes in [oxCCO]. ..
  24. ncbi request reprint Theoretical investigation of measuring cerebral blood flow in the adult human head using bolus Indocyanine Green injection and near-infrared spectroscopy
    Terence S Leung
    Department of Medical Physics, University College London, London, UK
    Appl Opt 46:1604-14. 2007
    ..The dispersion of the arterial input function also affected the CBF estimates...
  25. doi request reprint Investigation of frontal cortex, motor cortex and systemic haemodynamic changes during anagram solving
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, Malet Place Engineering Building, Gower Street, University College London, London, UK WC1E 6BT
    Adv Exp Med Biol 614:21-8. 2008
    ..05) and flux (n = 9, p = 0.05). The task-related changes seen in MBP and flux in this study appear to contribute to the changes in the NIRS signals over both the activated and control regions of the cortex...
  26. pmc Modelling cerebrovascular reactivity: a novel near-infrared biomarker of cerebral autoregulation?
    David Highton
    University College Hospitals, Queen Square, London, UK
    Adv Exp Med Biol 765:87-93. 2013
    ..Further development of this technique could be used to track CVPR providing targets for individualised management of patients with altered vascular reactivity, minimising secondary neurological insults...
  27. doi request reprint Relationship between brain tissue haemodynamics, oxygenation and metabolism in the healthy human adult brain during hyperoxia and hypercapnea
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, Malet Place Engineering Building, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 645:315-20. 2009
    ..83, r=0.93 and r=0.82) but not with Vmca (r=0.33). We conclude that an increase in [oxCCO] was seen during both challenges and it was highly associated with brain tissue oxygenation...
  28. pmc Quantification of systemic interference in optical topography data during frontal lobe and motor cortex activation: an independent component analysis
    Sundeep Patel
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 701:45-51. 2011
    ..This analysis can therefore extract the true OT haemodynamic neuronal response and hence discriminate between regional activated cortical areas and global haemodynamic changes...
  29. pmc Changes in Cerebral Oxidative Metabolism during Neonatal Seizures Following Hypoxic-Ischemic Brain Injury
    Subhabrata Mitra
    Department of Neonatology, Institute for Women s Health, University College London, London, UK
    Front Pediatr 4:83. 2016
    ..The progressive decline in the Δ[oxCCO] baseline during seizures suggests a progressive decrease of mitochondrial oxidative metabolism. ..
  30. pmc Modelling Blood Flow and Metabolism in the Preclinical Neonatal Brain during and Following Hypoxic-Ischaemia
    Matthew Caldwell
    Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
    PLoS ONE 10:e0140171. 2015
    ..We discover that the model can explain this failure better when we include, among other factors such as mitochondrial uncoupling and poor cerebral blood flow restoration, the death of around 40% of the brain tissue. ..
  31. pmc Investigation of frontal lobe activation with fNIRS and systemic changes during video gaming
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, London, UK
    Adv Exp Med Biol 789:89-95. 2013
    ..However, in some channels over the frontal lobe, we also observed significant correlations between the HbO2 and systemic variables. ..
  32. pmc Systematic investigation of changes in oxidized cerebral cytochrome c oxidase concentration during frontal lobe activation in healthy adults
    Christina Kolyva
    Medical Physics and Bioengineering, University College London, London WC1E 6BT, UK
    Biomed Opt Express 3:2550-66. 2012
    ..We conclude that the heterogeneity in the Δ[oxCCO] response is physiological and not induced by confounding factors in the measurements...
  33. pmc Modelling noninvasively measured cerebral signals during a hypoxemia challenge: steps towards individualised modelling
    Beth Jelfs
    Department of Medical Physics and Bioengineering, University College London, London, United Kingdom
    PLoS ONE 7:e38297. 2012
    ..Discrepancies between model and data which persist despite model optimisation are used to flag up important questions concerning the underlying physiology, and the reliability and physiological meaning of the signals...
  34. ncbi request reprint Changes in cerebral oxygenation and haemodynamics during postural blood pressure changes in patients with autonomic failure
    Katharine Hunt
    Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery and Institute of Neurology, Queen Square, London WC1N 3BG, UK Centre for Anaesthesia, University College London, UK
    Physiol Meas 27:777-85. 2006
    ..Postural hypotension in patients with autonomic failure is associated with a substantial decrease in absolute cerebral oxygenation measured by NIRS and this might reflect a critical reduction in cerebral oxygen delivery...
  35. ncbi request reprint Measurement of the optical properties of the adult human head with spatially resolved spectroscopy and changes of posture
    Terence S Leung
    Department of Medical Physics and Bioengineering, University College London, London WC1E 6JA, UK
    Adv Exp Med Biol 540:13-8. 2003
  36. ncbi request reprint Hyperoxia results in increased aerobic metabolism following acute brain injury
    Arnab Ghosh
    Neurocritical Care, University College London Hospitals, National Hospital for Neurology and Neurosurgery, London, UK
    J Cereb Blood Flow Metab . 2016
    ..Diffusion limitation or mitochondrial inhibition might explain these findings. Further investigation is warranted to establish optimal oxygenation to sustain aerobic metabolism after acute brain injury...
  37. pmc Immediate remote ischemic postconditioning after hypoxia ischemia in piglets protects cerebral white matter but not grey matter
    Mojgan Ezzati
    Institute for Women s Health, University College London, London, UK
    J Cereb Blood Flow Metab 36:1396-411. 2016
    ..Immediate RIPostC is a potentially safe and promising brain protective therapy for babies with NE with protection in white but not grey matter. ..
  38. pmc Monitoring cerebral autoregulation after brain injury: multimodal assessment of cerebral slow-wave oscillations using near-infrared spectroscopy
    David Highton
    From the Department of Neurocritical Care, National Hospital for Neurology and Neurosurgery, University College London Hospitals NHS Trust, London, United Kingdom and the Department of Medical Physics and Bioengineering, University College London, London, United Kingdom
    Anesth Analg 121:198-205. 2015
    ..The aim of this study is to identify the relationship between NIRS signal oscillations and multimodal neuromonitoring, examining the utility of near infrared derived indices of cerebrovascular reactivity...
  39. pmc Modelling blood flow and metabolism in the piglet brain during hypoxia-ischaemia: simulating pH changes
    Tharindi Hapuarachchi
    CoMPLEX, University College London, London, UK
    Adv Exp Med Biol 789:331-7. 2013
    ..We show that both NIRS and MRS measurements are predicted well in the new version of the model. ..
  40. pmc Oscillations in cerebral haemodynamics in patients with falciparum malaria
    Christina Kolyva
    Department of Medical Physics and Bioengineering, University College London, London, UK
    Adv Exp Med Biol 765:101-7. 2013
    ..This may be related to autonomic dysfunction in severe malaria, a topic of little research to date. The present study demonstrated that application of NIRS in a resource-poor setting is feasible and has potential as a research tool...
  41. pmc Computational modelling of the piglet brain to simulate near-infrared spectroscopy and magnetic resonance spectroscopy data collected during oxygen deprivation
    Tracy Moroz
    CoMPLEX, University College London, London, UK
    J R Soc Interface 9:1499-509. 2012
    ..Finally, the model is used to investigate hypotheses regarding changes in CCO redox state during anoxia...
  42. pmc Effects of assuming constant optical scattering on haemoglobin concentration measurements using NIRS during a Valsalva manoeuvre
    Lei Gao
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 701:15-20. 2011
    ..However, these scattering changes do not appear to significantly affect the differential pathlength factor and the tissue haemoglobin concentration measurements...
  43. doi request reprint Interrelationship Between Broadband NIRS Measurements of Cerebral Cytochrome C Oxidase and Systemic Changes Indicates Injury Severity in Neonatal Encephalopathy
    Gemma Bale
    Biomedical Optics Research Laboratory, University College London, London, UK
    Adv Exp Med Biol 923:181-6. 2016
    ..Broadband NIRS measured concentration changes of the oxidation state of cytochrome c oxidase has the potential to become a useful cotside tool for assessment of injury severity following hypoxic ischaemic brain injury. ..
  44. doi request reprint Relationship Between Cerebral Oxygenation and Metabolism During Rewarming in Newborn Infants After Therapeutic Hypothermia Following Hypoxic-Ischemic Brain Injury
    Subhabrata Mitra
    Institute for Women s Health, University College London and Neonatal Unit, University College London Hospitals Trust, London, UK
    Adv Exp Med Biol 923:245-51. 2016
    ..41 (±0.27), 0.22 (±0.21) and 0.01, respectively. The relationship between mitochondrial metabolism and oxygenation became impaired with rising Lac/NAA. Cardiovascular parameters remained stable during rewarming. ..
  45. pmc BrainSignals Revisited: Simplifying a Computational Model of Cerebral Physiology
    Matthew Caldwell
    Department of Medical Physics and Biomedical Engineering, University College London, London, UK
    PLoS ONE 10:e0126695. 2015
    ..In conditions where the simplified models are applicable, their greater efficiency has potential to allow their use at the bedside to help interpret clinical data in near real-time. ..
  46. pmc Analysis of slow wave oscillations in cerebral haemodynamics and metabolism following subarachnoid haemorrhage
    David Highton
    Neurocritical Care, University College Hospitals, Queen Square, London, UK
    Adv Exp Med Biol 812:195-201. 2014
    ..1Hz-0.01Hz consistent with compromised flow-metabolism coupling. NIRS derived variables might offer unique insights into microvascular and metabolic dysfunction following SAH, and in the future identify therapeutic windows or targets...
  47. pmc Cerebral and peripheral tissue oxygenation in children supported on ECMO for cardio-respiratory failure
    Maria D Papademetriou
    Biomedical Optics Research Laboratory, Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 662:447-53. 2010
    ..Spectral analysis was performed on the oxyhaemoglobin data collected from these patients with the aim of comparing oscillations at range of frequencies appearing in the two measurement sites...
  48. doi request reprint False positives in functional near-infrared topography
    Ilias Tachtsidis
    Department of Medical Physics and Bioengineering, Malet Place Engineering Building, University College London, Gower Street, London WC1E 6BT, UK
    Adv Exp Med Biol 645:307-14. 2009
    ..This lead to false positive haemodynamic maps of activation. It is therefore necessary to use statistical testing that incorporates the systemic changes that occur during brain activation...
  49. ncbi request reprint Near-infrared spectroscopic quantification of changes in the concentration of oxidized cytochrome c oxidase in the healthy human brain during hypoxemia
    Martin M Tisdall
    The National Hospital for Neurology and Neurosurgery, Department of Neuroanaesthesia and Neurocritical Care, Queen Square, London WC1N 3BG, United Kingdom
    J Biomed Opt 12:024002. 2007
    ..This is the first description of cerebral Delta[oxCCO] during hypoxemia in healthy adults. Studies are ongoing to investigate the clinical relevance of this signal in patients with traumatic brain injury...
  50. pmc Towards a wearable near infrared spectroscopic probe for monitoring concentrations of multiple chromophores in biological tissue in vivo
    Danial Chitnis
    Department of Medical Physics and Biomedical Engineering, University College London, London WC1E 6BT, United Kingdom
    Rev Sci Instrum 87:065112. 2016
    ..The multi-wavelength capabilities and portability of this spectroscopic probe will create significant opportunities for in vivo studies in a range of clinical and life science applications. ..
  51. pmc Multi-channel multi-distance broadband near-infrared spectroscopy system to measure the spatial response of cellular oxygen metabolism and tissue oxygenation
    Phong Phan
    Department of Medical Physics and Biomedical Engineering, UCL, London WC1E 6BT, UK
    Biomed Opt Express 7:4424-4440. 2016
    ..There was no observable TOI functional response and we have shown small variations in TOI across different sites within the same subject and within the same site across subjects...
  52. doi request reprint Near Infrared Light Scattering Changes Following Acute Brain Injury
    David Highton
    Neurocritical Care, University College Hospitals, Queen Square, London, UK
    Adv Exp Med Biol 876:139-44. 2016
    ....
  53. pmc Simulating NIRS and MRS measurements during cerebral hypoxia-ischaemia in piglets using a computational model
    T Hapuarachchi
    CoMPLEX, University College London, London, UK
    Adv Exp Med Biol 812:187-93. 2014
    ..The model fits the data reasonably and suggests a 20 % drop in glucose consumption, a ~65 % increase in lactate concentration and ~35 % drop in the cerebral metabolic rate of oxygen (CMRO₂) during HI...
  54. pmc Modelling confounding effects from extracerebral contamination and systemic factors on functional near-infrared spectroscopy
    Matthew Caldwell
    University College London, Department of Medical Physics and Biomedical Engineering, Biomedical Optics Research Laboratory, Gower Street, London WC1E 6BT, United Kingdom
    Neuroimage 143:91-105. 2016
    ..It is therefore important to record the major potential confounders in the course of fNIRS experiments. Our model may then allow the observed behaviour to be attributed among the potential causes and hence reduce identification errors...
  55. doi request reprint In Vivo Measurement of Cerebral Mitochondrial Metabolism Using Broadband Near Infrared Spectroscopy Following Neonatal Stroke
    Subhabrata Mitra
    Institute for Women s Health, University College London and Neonatal Unit, University College London Hospitals Trust, London, UK
    Adv Exp Med Biol 876:493-9. 2016
    ..Changes in cerebral oxygenation (measured as HbDiff=HbO2-HHb) and cerebral metabolism (measured as oxCCO) were highly coupled on the injured side of the brain...
  56. pmc Development of a near infrared multi-wavelength, multi-channel, time-resolved spectrometer for measuring brain tissue haemodynamics and metabolism
    Luke Dunne
    Department of Medical Physics and Bioengineering, University College London, Malet Place Eng Building, Gower Street, London, WC1E 6BT, UK
    Adv Exp Med Biol 812:181-6. 2014
    ....
  57. pmc Erratum: Publisher's note: False positives and false negatives in functional near-infrared spectroscopy: issues, challenges, and the way forward
    Ilias Tachtsidis
    University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, Malet Place Engineering Building, WC1E 6BT, London, United Kingdom
    Neurophotonics 3:039801. 2016
    ..This corrects the article DOI: 10.1117/1.NPh.3.3.031405.]. ..
  58. pmc False positives and false negatives in functional near-infrared spectroscopy: issues, challenges, and the way forward
    Ilias Tachtsidis
    University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, Malet Place Engineering Building, WC1E 6BT, London, United Kingdom
    Neurophotonics 3:031405. 2016
    ..Here, we summarize the possible physiological origins of these issues and suggest ways to avoid and remove them. ..
  59. doi request reprint False positives and false negatives in functional near-infrared spectroscopy: issues, challenges, and the way forward
    Ilias Tachtsidis
    University College London, Department of Medical Physics and Biomedical Engineering, Gower Street, Malet Place Engineering Building, WC1E 6BT, London, United Kingdom
    Neurophotonics 3:030401. 2016
    ..Here, we summarize the possible physiological origins of these issues and suggest ways to avoid and remove them. ..
  60. pmc Investigation of cerebral autoregulation in the newborn piglet during anaesthesia and surgery
    Gemma Bale
    Biomedical Optics Research Laboratory, University College London, Malet Place Engineering Building, Gower St, London, WC1E6BT, UK
    Adv Exp Med Biol 812:165-71. 2014
    ..Presence of CA impairment was not significant but found to increase with surgical exacerbation. The impairment did not correlate with histological outcome (presence of cell death, apoptosis and microglial activation in the brain). ..
  61. doi request reprint Dual role of cerebral blood flow in regional brain temperature control in the healthy newborn infant
    Sachiko Iwata
    Centre for Developmental and Cognitive Neuroscience, Department of Paediatrics and Child Health, Kurume University School of Medicine, Kurume, Fukuoka, Japan Institute for Women s Health, University College London, London, UK
    Int J Dev Neurosci 37:1-7. 2014
    ..Further studies are required to assess the effect of cerebral metabolism and perfusion on regional brain temperature in low-cardiac output conditions, fever, and with therapeutic hypothermia...
  62. ncbi request reprint A physiological model of cerebral blood flow control
    Murad Banaji
    Department of Medical Physics and Bioengineering, University College London, Gower Street, London WC1E 6BT, UK
    Math Biosci 194:125-73. 2005
    ..The simulations presented are preliminary, but show qualitative agreement between model behaviour and experimental results...
  63. ncbi request reprint Rate of change in cerebral oxygenation and blood pressure in response to passive changes in posture: a comparison between pure autonomic failure patients and controls
    Ilias Tachtsidis
    Adv Exp Med Biol 566:187-93. 2005
    ..05). MBP slope magnitudes showed significant differences for phases 2 (P < .01) and 5 (P < .01). These differences in the rate of change suggest differences in blood vessel resistance related to sympathetic activation...
  64. doi request reprint Increase in cerebral aerobic metabolism by normobaric hyperoxia after traumatic brain injury
    Martin M Tisdall
    Department of Neuroanaesthesia and Neurocritical Care, The National Hospital for Neurology and Neurosurgery, UK
    J Neurosurg 109:424-32. 2008
    ..They investigated the effects on cellular and mitochondrial redox states measured by the brain tissue lactate/pyruvate ratio (LPR) and the change in oxidized cytochrome c oxidase (CCO) concentration, respectively...
  65. ncbi request reprint Circulation time in man from lung to periphery as an indirect index of cardiac output
    Chris B Wolff
    Adv Exp Med Biol 566:311-6. 2005
    ..The relationship for normal subjects was: Ct = 0.28 x 60/Q(if) + 2.8 sec (Q(if) in L min.; P slope < .001)...