Aims and objectives
It is well known from physiology that respiration,
besides heart beating,
influences the venous return ,
but there is not a non-invasive study about how much the heart pulsation and the breathing amplitude and phase affect the venous flow.
The breathing control,
during an investigation of the neck and head venous return,
especially when the examined subject is lying supine,
because the breath influences the vessel dimension and the kind and amount of flow.
For the examination...
Methods and materials
Subjects Eleven volunteers (9 men and 2 women),
with median age of 39 years (range: 26-50) were recruited for the study.
They stayed supine for the entire examination,
lying on an electro-mechanical tilting chair (Givas AP4295,
A head support was used in order to have the subject’s neck in the proper position,
avoiding hypo- or hyper-extensions.
The respiratory activity was measured simultaneously with the US examination for all the subjects.
For two subjects,
the ECG was...
The average exam length for each subject was 25 minutes (including 5 minutes of subject’s rest before starting the US scanning).
The respiratory sensor was placed on the thorax left side in 2 subjects,
on the abdomen left side in 7 subjects and on the abdomen right side in 2 subjects.
Clear changes in the IJV and VV blood flow velocities were observed with the PW measures.
the venous dynamics were synchronous with the breathing phases: in all the examined subjects,
This preliminary study allowed us to verify the feasibility of the respiratory activity measurement,
simultaneously with all the US modalities of interest for the venous examination.
Positioning the respiratory sensor on the clothes in 9 subjects revealed no degradation in the signal characteristics,
in comparison to those 2 with the sensor not positioned on the clothes.
This supports the described setting as usable in a clinical context,
since it is simple and quick to be positioned,
Maria Marcella Laganà Fondazione Don Carlo Gnocchi ONLUS,
Italy email@example.com Leonardo Forzoni Esaote S.p.A.,
Nordenström and A.
"Effect of respiration on venous return to the heart.," vol.
1965.  P.
Bartolomei and F.
"Chronic cerebrospinal venous insufficiency in patients with multiple sclerosis," J. Neurol. Neurosurg. Psychiatry.,
2009.  P.
Tacconi and F.