Background
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The sleeve is a unique position-tolerant
sensor which is the only reliable way of making continuous
recordings of sphincter pressure, apart from an extensive
chain of very closely spaced sideholes
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Reliable measurement of lower oesophageal
sphincter relaxation is an especially important clinical
application of the sleeve.
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Water perfusion is essential for functioning
of the sleeve.
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Dentsleeve
Technical Note 2, Version 2, gives more detailed information
on sleeve functioning. |
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Sleeve
length
The normal range of sphincter movement
should be within the length of the sleeve to ensure that sphincter
pressure is recorded continuously.
The range of sphincter movement varies according to body size
and sphincter type.
Recommended sleeve lengths given below are only indicative;
the best sleeve length depends on the application, and in some
cases, the mode of intubation. Dentsleeve
can advise.
Sleeve length is best kept to the minimum consistent with maintenance
of contact with the sphincter, as recordings from excessively
long sleeves will be more influenced by motor events above and
below the sphincter.
Excessively long sleeves also have very low rates of pressure
rise at their distal end (see page 65). |
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Sleeve
width
The width of the cross section of the sleeve
sensor is varied in approximate proportion to the diameter of
the extrusion on which it is built.
Variation of sleeve sensor width ensures that the sleeve does
not add excessive bulk to the cross section of the extrusion
on which it is built. The sleeve sensor width is chosen to match
the perfusion rate required for adequate sleeve performance
to the appropriate perfusion rate for side hole channels incorporated
into a particular manometric assembly. |
Sleeve
cross section
All sleeve assembly cross sections other than upper oesophageal
sphincter sleeves are designed to be as close to circular as
possible.
Upper oesophageal sphincter sleeves are made to be close to
oval, so that the sleeve self orientates in the anterior-posterior
position within the sphincter.
Sleeve water perfusion rates
Sleeves sense sphincter pressure optimally within a relatively
narrow range of perfusion rates. The
optimal perfusion rate is defined by the width and length
of the sleeve sensor. |
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If a sleeve is perfused at a rate more
than double that recommended, this will lead to an undermeasurement
at the proximal end of the sleeve of 2-3 mmHg.
If a sleeve is perfused at a rate slower than that recommended,
the rate of pressure rise achieved by the sleeve may be too
low for reliable recording.
The sleeve design is matched to the diameter of the manometric
channels of the extrusion on which the sleeve is built.
For a particular sphincter and extrusion, the recommended
rate of perfusion will give pressure rise rates that are adequate
for recordings of both sphincter pressure and peristaltic
pressures in the adjacent non-sphincter regions (see table
below).
Dentsleeve Technical Note
2 Version 2 gives more detailed explanation on sleeve perfusion
and pressure rise rates. |
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