Adaptive method for assessment of cerebrospinal fluid outflow conductance

Andersson, Niklas; Malm, Jan; Wiklund, Urban; Eklund, Anders

doi:10.1007/s11517-006-0157-7

Cited by 7 publications

(5 citation statements)

References 22 publications

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“…Hemodynamics is used in numerous medical fields, mostly during surgical procedures or afterwards in the recovery room where the blood pressure is being measured by an in line arterial tube [12][13][14][15]. This device measures blood pressure noninvasively using hemodynamics, and therefore is entirely different compared to other instruments in this field [8].…”

Section: Mathematical Model Preliminarymentioning

confidence: 99%

New Method for Computing Optical Hemodynamic Blood Pressure

Segman¹

2016

J Clin Exp Cardiolog

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Objective: Hypertension is a major risk indicator for coronary heart diseases, renal failure, stroke and other various illnesses, and it is the primary global risk for mortality. Blood pressure measurements are essential for managing the risks resulting from hypertension. In this paper we will present a new device, the TensorTip MTX, which computes hemodynamic blood pressure noninvasively.Methods: This paper presents a technique that uses the color imaging resulting from a set of monochrome light source that traverse the tissue under consideration and is projected onto the color image sensor. A new extended solution of the Windkessel model is being displayed and provides additional insight on various functional resistances rather than a constant resistance. Results:The TensorTip MTX was clinically evaluated in few medical centers and was found to perform well at standard blood pressure measurements and also monitoring patients who suffered from alterations in blood pressure due to cardiac surgery. The device passed successfully our clinical trials and fulfilled the ISO 81060-2 recognized accuracy requirements for various notified bodies. Conclusions:In this work it was found that the variation in the pressure flow can be determined from the changes in the height of the temporal color histograms and additional temporal volume information.Significance: Today, the most common technique is the oscillometric technique based on the sphygmomanometer arm cuff pressure. This paper presents a new device, the TensorTip MTX, which computes hemodynamic blood pressure noninvasively, cuff-less and free of air pumping.

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Section: Mathematical Model Preliminarymentioning

confidence: 99%

New Method for Computing Optical Hemodynamic Blood Pressure

Segman¹

2016

J Clin Exp Cardiolog

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“…ICP signals are analysed for forecasting critical intracranial and cerebrovascular pathophysiological variations [3,8,13] and for predicting shunt responsiveness during the management of CSF disorders. Unfortunately, invasive techniques are used to collect ICP using external pressure sensors and infusion test [2,6] that endanger the patients' life.…”

Section: Intracranial Hydrodynamics Modelmentioning

confidence: 99%

A mechatronic valve in the management of hydrocephalus: methods and performance

Momani

Al-Nuaimy

Al-Jumaily

et al. 2010

Med Biol Eng Comput

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The problem of excess cerebrospinal fluid in the brain (hydrocephalus) is generally managed using a passive pressure or flow regulated mechanical shunt. Despite the success of such devices, they have been plagued with a number of problems. It is desirable to have a shunt valve that responds dynamically to the changing needs of the patient, opening and closing according to a dynamic physiological pattern, rather than simply to the hydrostatic pressure across the valve. Such a valve would by necessity be mechatronic, electronically controlled by software. In this article, different methods for controlling such a mechatronic valve are explored, and the effect of current hydrocephalus management techniques on the intracranial hydrodynamics of acute hydrocephalus patient compared with those based on a mechatronic valve was investigated using numerical simulation. Furthermore, the performance of these techniques was evaluated based on a proposed multi-dimensional figure of merit. In addition, an empirical valve schedule was proposed based on different criterions. An intelligent shunting system is seen as the future in hydrocephalus management and treatment, and towards this end, suitably programmed mechatronic valves would attempt to mimic normal physiology and potentially overcome many of the problems associated with current mechanical valves.

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“…These metrics can be computed through the infusion of a specific fluid volume into the CSF space while simultaneously recording CSFP. Infusion testing was established in NPH as a safe complementary diagnostic tool [ 33 ], with some drawbacks regarding the duration of examination (on the order of at least 1-h overall [ 1 ]) and difficulties to assess repeatability [ 42 ].…”

Section: Introductionmentioning

confidence: 99%

Queckenstedt’s test repurposed for the quantitative assessment of the cerebrospinal fluid pulsatility curve

et al. 2023

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Purpose Before the era of spinal imaging, presence of a spinal canal block was tested through gross changes in cerebrospinal fluid pressure (CSFP) provoked by manual compression of the jugular veins (referred to as Queckenstedt's test; QT). Beyond these provoked gross changes, cardiac-driven CSFP peak-to-valley amplitudes (CSFPp) can be recorded during CSFP registration. This is the first study to assess whether the QT can be repurposed to derive descriptors of the CSF pulsatility curve, focusing on feasibility and repeatability. Method Lumbar puncture was performed in lateral recumbent position in fourteen elderly patients (59.7±9.3 years, 6F) (NCT02170155) without stenosis of the spinal canal. CSFP was recorded during resting state and QT. A surrogate for the relative pulse pressure coefficient was computed from repeated QTs (i.e., RPPC-Q). Results Resting state mean CSFP was 12.3 mmHg (IQR 3.2) and CSFPp was 1.0 mmHg (0.5). Mean CSFP rise during QT was 12.5 mmHg (7.3). CSFPp showed an average 3-fold increase at peak QT compared to the resting state. Median RPPC-Q was 0.18 (0.04). There was no systematic error in the computed metrics between the first and second QT. Conclusion This technical note describes a method to reliably derive, beyond gross CSFP increments, metrics related to cardiac-driven amplitudes during QT (i.e., RPPC-Q). A study comparing these metrics as obtained by established procedures (i.e., infusion testing) and by QT is warranted.

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Adaptive method for assessment of cerebrospinal fluid outflow conductance

Cited by 7 publications

References 22 publications

New Method for Computing Optical Hemodynamic Blood Pressure

New Method for Computing Optical Hemodynamic Blood Pressure

A mechatronic valve in the management of hydrocephalus: methods and performance

Queckenstedt’s test repurposed for the quantitative assessment of the cerebrospinal fluid pulsatility curve

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