Analysis of phase shift between pulse oscillations of macro- and microvascular cerebral blood flow in patients with traumatic brain injury
Acta Neurochirurgica,
Год журнала:
2024,
Номер
166(1)
Опубликована: Авг. 2, 2024
Abstract
Purpose
After
a
traumatic
brain
injury
(TBI),
monitoring
of
both
macrovascular
and
microvascular
blood
circulation
can
potentially
yield
better
understanding
pathophysiology
potential
secondary
lesions.
We
investigated
the
changes
in
phase
shift
(PS)
between
cardiac-induced
oscillations
cerebral
flow
(CBF)
measured
at
macro
(ultrasound
Doppler)
(laser
level.
Further
we
assessed
impact
intracranial
pressure
(ICP)
on
PS
TBI
patients.
A
aim
was
to
compare
TCD-derived
arterial
time
constant
(τ),
parameter
that
reflects
circulatory
transit
time.
Methods
TCD
velocities
(FV)
middle
artery,
laser
Doppler
microcirculation
flux
(LDF),
(ABP),
ICP
were
monitored
29
consecutive
patients
with
TBI.
Eight
excluded
because
poor-quality
signals.
For
remaining
21
(median
age
=
23
(Q1:
20–Q3:
33);
men:16,)
data
retrospectively
analysed.
fundamental
harmonics
FV
LDF
signals
determined
using
spectral
analysis.
τ
estimated
as
product
cerebrovascular
resistance
compliance,
based
mathematical
transformation
ABP,
pulse
waveforms.
Results
negative
(median:
−26
−38–Q3:
−15)
degrees)
indicating
heart
rate
frequency
lagged
behind
pulse.
With
rising
mean
ICP,
became
more
(R
−0.51,
p
<
0.019)
delay
increases.
There
significant
correlation
−0.47,
0.03).
Conclusions
Pulse
divergence
greater
elevated
likely
reflecting
prolonged
travel
Язык: Английский
Stand-alone segmentation of blood flow pulsatility measured with diffuse correlation spectroscopy
Biomedical Optics Express,
Год журнала:
2024,
Номер
15(10), С. 6052 - 6052
Опубликована: Сен. 9, 2024
We
present
a
stand-alone
blood
flow
index
(BFI)
pulse
segmentation
method
for
diffuse
correlation
spectroscopy
that
uses
wavelet-based
representation
of
the
BFI
signal
at
cardiac
frequency
in
place
an
exogenous
physiological
reference.
use
this
to
quantify
waveform
morphology
cohort
30
healthy
adults.
demonstrate
features
obtained
with
wavelet
approach
strongly
agree
those
using
pressure
reference
signal.
These
results
suggest
promise
quantifying
morphological
features.
Язык: Английский