US2012165689A1PendingUtilityA1
Catheter with common guide wire and indicator lumen
Est. expiryFeb 20, 2022(expired)· nominal 20-yr term from priority
A61B 5/028A61B 5/6855
46
PatentIndex Score
0
Cited by
0
References
0
Claims
Abstract
A catheter for retrograde orientation in a blood flow is used to determine the blood flow rate by thermodilution measurements. The determination of the blood flow rate accommodates injectate induced thermal influences on a dilution thermal sensor, wherein the thermal influences can occur prior to introduction of the injectate into the blood flow.
Claims
exact text as granted — not AI-modified1 . A catheter comprising:
(a) an elongate catheter body having a proximal end and a distal end, the elongate catheter body including an indicator lumen extending from the proximal end to the distal end, the indicator lumen having (i) a terminal opening at the distal end, the terminal opening having a restricted cross sectional area and (ii) a radial injection port longitudinally intermediate the proximal end and the terminal opening; (b) a dilution sensor connected to the elongate catheter body longitudinally intermediate the proximal end and the distal end; and (c) a guide wire extending through the indicator lumen from the proximal end to the distal end and through the terminal opening to project from the distal end of the elongate catheter body, and define a gap between the guide wire and the elongate catheter body at the terminal opening, the gap passing a portion of an indicator from the indicator lumen.
2 . The catheter of claim 1 , wherein the dilution sensor is a thermistor.
3 . The catheter of claim 1 , further comprising a controller connected to the dilution sensor, the controller configured to determine a blood flow rate corresponding to passage of the indicator through the indicator lumen.
4 . The catheter of claim 1 , wherein the catheter body is configured as a retrograde catheter.
5 . The catheter of claim 1 , further comprising a controller connected to the dilution sensor, the controller configured to determine a blood flow rate corresponding to a relationship
Q
=
k
(
T
b
-
T
i
)
·
V
(
1
-
a
)
S
,
where Q is the blood flow rate, k is a coefficient related to thermal capacity of a measured flow and the indicator, T b is a temperature of a measured flow prior to injection of the indicator, T i is a temperature of the indicator prior to entering the measured flow, V is a volume of the indicator, S is an area under a temperature versus time curve resulting from a mixing of the indicator, and a is a portion of the indicator passing through the terminal opening.
6 . The catheter of claim 1 , further comprising a controller connected to the dilution sensor, the controller configured to determine a blood flow rate corresponding to a relationship
Q
=
k
(
T
b
-
T
i
)
·
V
(
1
-
a
)
(
S
m
-
S
in
)
,
where Q is a blood flow rate, k is a coefficient related to thermal capacity of a measured flow and the indicator, T b is the temperature of the measured flow prior to injection, T i is the temperature of the indicator prior to entering the measured flow, V is the volume of the indicator, S m is the total area under the temperature versus time curve resulting from a mixing of the indicator with the blood flow, S in is the part of the area under the dilution curve related to a cooling thermal change of a sensor inside the catheter body and a is the portion of the indicator passing through the terminal opening.
7 . The catheter of claim 1 , wherein the dilution sensor is longitudinally intermediate the terminal opening and the radial injection port.
8 . A catheter assembly comprising:
(a) an elongate catheter body having a proximal end and a distal end, the elongate catheter body including an indicator lumen extending from the proximal end to the distal end, the indicator lumen having a terminal opening at the distal end, the terminal opening defined by a reduced cross sectional area, the elongate catheter body having a radial injection port longitudinally intermediate the terminal opening and the proximal end of the catheter body; (b) a guide wire extending through the indicator lumen from the proximal end to the distal end and through the terminal opening, the guide wire is sized to be slideably received through the reduced cross sectional area; and (c) a controller connected to the catheter body, the controller configured to calculate a blood flow corresponding to a passage of indicator from the indicator lumen.
9 . The catheter assembly of claim 8 , wherein the indicator lumen has a reduced cross sectional area adjacent the distal end and the guide wire is sized to reduce passage of the indicator through the reduced cross sectional area.
10 . The catheter assembly of claim 8 , wherein the indicator lumen terminates at the distal end of the catheter body.
11 . The catheter assembly of claim 8 , further comprising a dilution sensor connected to the elongate catheter body.
12 . The catheter assembly of claim 11 , wherein the dilution sensor is a thermistor.
13 . The catheter assembly of claim 8 , further comprising a dilution sensor connected to the elongate catheter body, the dilution sensor located longitudinally intermediate the radial injection port and the terminal opening.
14 . The catheter assembly of claim 8 , wherein a portion of the guide wire is disposed in the terminal port and the controller is selected to compensate for passage of the indicator through the terminal port.
15 . The catheter assembly of claim 8 , wherein the controller is selected to compensate for passage of a volume of the indicator through the terminal opening corresponding to the relationship
Q
=
k
(
T
b
-
T
i
)
·
V
(
1
-
a
)
S
,
where Q is a blood flow rate, k is a coefficient related to thermal capacity of a measured flow and the indicator, T b is the temperature of the measured flow prior to injection, T i is the temperature of the indicator prior to entering the measured flow, V is the volume of the indicator, S is the area under the temperature versus time curve resulting from the mixing of the indicator and a is the portion of the indicator passing through the terminal opening.
16 . The catheter assembly of claim 8 , wherein the controller is selected to compensate for passage of a volume of the indicator through the terminal opening corresponding to the relationship
Q
=
k
(
T
b
-
T
i
)
·
V
(
1
-
a
)
(
S
m
-
S
in
)
,
where Q is a blood flow rate, k is a coefficient related to thermal capacity of a measured flow and the indicator, T b is the temperature of the measured flow prior to injection, T i is the temperature of the indicator prior to entering the measured flow, V is the volume of the indicator, S m is the total area under the temperature versus time curve resulting from the mixing of the indicator, S in is the part of the area under the dilution curve related to a cooling of a sensor inside the catheter body and a is the portion of the indicator passing through the terminal opening.Cited by (0)
No later patents cite this yet.
References (0)
No backward citations on record.