WO2006102260A2 - Intravenous fluid warming system - Google Patents
Intravenous fluid warming system Download PDFInfo
- Publication number
- WO2006102260A2 WO2006102260A2 PCT/US2006/010099 US2006010099W WO2006102260A2 WO 2006102260 A2 WO2006102260 A2 WO 2006102260A2 US 2006010099 W US2006010099 W US 2006010099W WO 2006102260 A2 WO2006102260 A2 WO 2006102260A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- fluid
- covers
- heat exchange
- temperature
- fluid warming
- Prior art date
Links
Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
- A61M5/44—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests having means for cooling or heating the devices or media
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2205/00—General characteristics of the apparatus
- A61M2205/36—General characteristics of the apparatus related to heating or cooling
- A61M2205/3653—General characteristics of the apparatus related to heating or cooling by Joule effect, i.e. electric resistance
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
- A61M2205/00—General characteristics of the apparatus
- A61M2205/58—Means for facilitating use, e.g. by people with impaired vision
- A61M2205/583—Means for facilitating use, e.g. by people with impaired vision by visual feedback
Definitions
- IV fluid warming devices are known that heat an IV fluid prior to introducing the fluid into a patient. Warmed IV fluids that are administered at very low flow rates can cool as they flow down the IV tubing to the patient. Often this heat loss is ignored.
- One prior art approach has been to simply heat the fluid to 41°C to try to overcome the loss for all flow rates.
- fluid passes along a generally serpentine fluid flow path through a removable/disposable heat exchange body.
- the heat exchange body is in thermal contact with a resistive film heater via thermally conductive layers interposed between the heat exchange body and the heater.
- Temperature sensors are provided that sense the temperature of the heat exchange body and of the heater.
- a fluid warming system in one aspect of the present invention, includes a pair of sliding covers that maintains a removable heat exchange body in place in heat exchange communication with a heater assembly.
- the heat exchange body is pressed in place by the covers in the closed position to guarantee good thermal conductivity. Fluid passing through the heat exchange body remains visible to the user.
- the heat exchange body is easily inserted and removed by sliding the covers to a open position.
- the moving covers can double as user input mechanisms by turning the power on and off and muting alarms.
- the covers do not cover any indicators present on the heat exchange body.
- the covers can be readily removed for cleaning, and the covers can be used as a mounting mechanism.
- power to the heater can be increased or decreased to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient .
- Fig. 1 is an isometric view of a fluid warming device illustrating slidable covers in a closed position according to the present invention
- Fig. 2 is an isometric view of the fluid warming device of Fig. 1 illustrating the slidable covers in a half closed position;
- Fig. 3 is an isometric exploded view of the fluid warming device of Fig. 1 with the slidable covers in an open position and a disposable set removed;
- Fig. 4 is an isometric view of a main body of the housing of the device of Fig. 1 with the slidable covers fully removed;
- Fig. 5 is a plan view of the device of Fig. 2;
- Fig. 6 is a cross sectional view taken along line A-A of Fig. 5;
- Fig. 7 is a schematic view of a disposable set and heater assembly of the fluid warming device of Fig. 1;
- Fig. 8 is a side view of a further embodiment of a fluid warming device illustrating gripping faces on the slidable covers;
- Fig. 9 is a flow chart illustrating a system for adjusting power to a heater of a fluid warming device to accommodate heat loss in an IV tubing at low flow rates;
- Fig. 10 is a graph illustrating heat loss across a disposable set heat exchange body and along a length of IV tubing and their combined heat losses,- and
- Fig. 11 is a graph illustrating temperature loss for various lengths of IV tubing and various flow rates.
- a fluid warming device 10 is illustrated in Figs. 1-7.
- the fluid warming device includes a housing 12 having a main body 14 and two sliding covers 16. Within the housing, supported by the main body, are a removable heat exchange body 18 and a heater assembly 20.
- the sliding covers are independently slidable to a closed position in which they retain the removable heat exchange body in place, as described more fully below.
- the slidable covers are preferably identical.
- the removable heat exchange body 18 and the heating assembly 20 are illustrated schematically in Fig. 7.
- the heat exchange body also called a disposable or removable set, includes an input port 22 connectable to an IV tubing line from a source of IV fluid, which may include an infusion pump.
- the disposable set also includes an output port 24 connectable to a further IV tubing line to deliver the IV fluid to the patient.
- the IV fluid flows along a flow path (not shown) having a serpentine or other suitable configuration between the input and output ports to optimize heat transfer to the fluid. See, for example, US Patent Pub. No. 2005-0008354, the disclosure of which is incorporated by reference herein.
- the disposable set is formed from any suitable material, such as aluminum, to facilitate heat transfer to the fluid flowing therein. When inserted in the housing with the sliding covers in a closed position, the disposable set is held in thermal contact with the heater assembly, so that heat transfer from the heater assembly to the disposable set causes heating of an IV fluid flowing therethrough.
- the heater assembly 20 is affixed within the main body 14 of the housing 12.
- the heater assembly includes a heater 26 and one or more thermally conductive layers 28, 30 interposed between the disposable set and the heater.
- the heater is an electrically powered resistive thin film heater.
- a power line 32 to the heater from a suitable power source is provided.
- the device may include a battery compartment or a connection to a battery pack, for example, for portable operation.
- Temperature sensors 34, 36 are provided that sense the temperature of the disposable set and of the heater. See, for example, US Patent Pub. No. 2005-0008354.
- the thermally conductive layers also electrically insulate the disposable set from the resistive heater.
- One thermally conductive layer 28 may suitably comprise a phase transition material
- the other thermally conductive layer 30 may suitably comprise a material such as a graphite to optimize heat transfer between the heater and the disposable set. See, for example, US Patent Pub. No. 2005-0008354. It will be appreciated that other or further thermally conductive layers may be provided.
- the main body 14 includes a compartment 38 on one side to receive the disposable set 18 in contact with an exposed surface 40 of the uppermost thermally conductive layer 30.
- the heat exchange body or disposable or disposable set 18 is removable from the housing.
- the disposable set can be removed from the main body of the housing by sliding the two opposed sliding covers outwardly in opposite directions. In this manner, the removable set can be lifted out of the housing with the IV tubing still attached to the input and output connectors, without breaking the fluid path.
- Finger cutouts 42 may be provided for ease of grasping the disposable set in the main body.
- the main body 14 of the housing includes protruding longitudinal tracks 46 along two opposed longitudinal outer wall surfaces of the main body. See Fig. 5.
- the sliding covers include complementary longitudinal recesses 48 along inner wall surfaces that mate with the tracks and allow the covers to slide axially along the main body. When in the closed position, the sliding covers extend over the edges of the disposable set within the recess of the main body, thereby retaining the disposable set therein. See Fig. 1.
- the covers also compress the disposable set to the outermost thermally conducting surface 40 of the heater assembly. This compression provides the necessary pressure for proper heat transfer between the heater assembly and the disposable set.
- the covers are retained in the closed position by frictional engagement with the disposable set Alternatively, any suitable latching or retaining mechanism may be provided.
- the covers 16 do not block the view of the bulk of the mid portion of the disposable set 18, allowing the operator to view the fluid passing through the disposable set.
- the disposable set is also keyed to the main body 14 in any suitable manner so that it fits within the compartment in the correct orientation. For example, one end 47 of the disposable set may be rounded to fit within an correspondingly rounded portion 49 of the compartment 38.
- the disposable set may include an arrow 50 thereon to provide an indication of the direction of flow, so that the disposable set is inserted in the housing in the correct orientation. The covers do not block this arrow.
- the main body preferably includes indicator lights, such as LEDs, thereon.
- indicator lights such as LEDs, thereon.
- one LED 52 may provide an indication of temperature at the output port
- another LED 54 may provide an indication that the heater is connected to the power source.
- the covers do not block these indicator lights either.
- the covers 16 can be maintained in two positions on the main body or can be removed fully from the main body. While on the main body, the covers can be in a fully closed position or an open position.
- the covers can include magnets or
- the covers can be maintained in a third or intermediate, half closed, position on the main body, described further below.
- the covers 16 apply full pressure to the disposable set 18 to ensure good thermal contact with the heater assembly.
- the sliding covers can also be used to turn the power on to commence warming and/or to activate any audible or visible alarm (s) .
- the half closed position see Fig. 2
- the disposable set is still held in place by the covers, but warming is stopped, the audible alarm is silenced, and the visual indicators are turned off.
- the status LED could be flashed in battery operation to inform the user that the warmer is connected to the battery and draining.
- the covers are in the open position (see Fig. 3) , the disposable set 18 can be inserted and removed. No heating takes place, the audible alarm is silenced, and visual indicators are turned off.
- the status LED could be flashed in battery operation to inform the user that the heater is connected to the battery and draining.
- any suitable latching or retaining mechanism can be provided to retain the covers in the desired positions relative to the main body.
- recessed surfaces 62 are provided on the main body 14 that latch with corresponding tabs 64 on the covers in the open position, preventing the covers from readily coming off the main body.
- the tabs 64 abut surfaces 63 to hold the covers in the closed position.
- Finger grips 68 are provided to aid in grasping the covers to push or pull them to the desired position.
- the closed (and power on) position can be indicated by arrows 70 and an adjacent "ON" marking on the covers.
- the open (and power off) position can be indicated by arrows 72 and an adjacent "OFF" marking on the covers .
- the covers can be fully removed from the main body in any suitable manner, for example, by the insertion of a suitable tool, such as a screw driver or dime, to lift the tab 64 over the surfaces 62.
- a suitable tool such as a screw driver or dime
- a latching or retaining mechanism can be configured to release simply by the use of sufficient force. Removal of the covers allows the device to be readily cleaned.
- passageways in the interior surfaces of the covers and a water tight main body housing allow cold sterilization by dipping in a sterilization fluid without complete removal of the covers.
- the sliding covers 14 may include opposed faces 74 that include gripping teeth thereon to form gripping faces.
- the gripping faces can be used to grip hospital clothing or bedding and hold the warmer in place to reduce stress on the IV line when the covers are fully closed.
- power to the heater can be increased or decreased to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient. More particularly, some IV fluids that have been warmed are administered at very low flow rates. These fluids cool as they travel down the IV tubing to the patient. The greater the difference between ambient temperature and the fluid temperature, the greater the radiated heat losses from the IV tubing.
- a suitable controller is provided to perform the calculations and communicate with the heater to make the desired adjustments.
- Heater power is determined by the difference between a target temperature (typically in the range of 39 to 41°C) , and the actual fluid temperature.
- the temperature drop across the heat exchanger is calculated (step 102) .
- This temperature drop is equal to the heater power divided by the thermal resistance of the heater assembly.
- the thermal resistance can be readily determined by one of skill in the art from the thickness, thermal conductivity and area of the materials between the heater and the fluid and stored as a constant.
- the controller calculates the temperature loss of the IV tubing to the environment (step 104) .
- the temperature loss is equal to this temperature difference multiplied by the radiation loss and divided by the heater power.
- the ambient temperature is measured by a suitable sensor located within the warming device in close contact with the housing, which is very close to ambient temperature.
- the radiation loss is a constant that is derived from experimentation with various lengths of the IV tubing and various flow rates . See Fig. 11.
- the controller determines if the IV tubing loss is greater than 1°C. Also at step 106, the controller also determines if the total drop along the IV tubing and across the heat exchanger is greater than a drop limit.
- the drop limit is the maximum temperature that the fluid can be artificially raised so that the allowable surface temperature on the heat exchanger is not exceeded, for example, no greater than 3 0 C from the desired target temperature. If the answer at step 106 is Yes, the actual fluid temperature is calculated at step 108 as the measured fluid output temperature minus the drop limit. If the answer at step 106 is No, the actual fluid temperature is calculated at step 110 as the fluid output temperature in the IV tubing drop minus the IV tubing drop (from step 102) minus the heat exchanger drop (from step 104) . Using the calculated value of the actual temperature, heater power is adjusted appropriately.
- the system allows the fluid warming device to be located a bit farther from the infusion site and still deliver normothermic fluid.
- the invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.
Landscapes
- Health & Medical Sciences (AREA)
- Vascular Medicine (AREA)
- Engineering & Computer Science (AREA)
- Anesthesiology (AREA)
- Biomedical Technology (AREA)
- Heart & Thoracic Surgery (AREA)
- Hematology (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Infusion, Injection, And Reservoir Apparatuses (AREA)
- External Artificial Organs (AREA)
Abstract
A fluid warming device includes axially or longitudinally slidable covers that retain a removable heat exchange body in a housing in heat exchange communication with a heater assembly while allowing flow through the heat exchange body to be observed. In another aspect, a fluid warming system increases or decreases power to a heater assembly to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient.
Description
TITLE OF THE INVENTION Intravenous Fluid Warming System
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims the benefit under 35 U. S. C. § 119 (e) of U.S. Provisional Application No. 60/663,857, filed on March 21, 2005, the disclosure of which is incorporated by reference herein.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR
DEVELOPMENT N/A
BACKGROUND OF THE INVENTION
Intravenous (IV) fluid warming devices are known that heat an IV fluid prior to introducing the fluid into a patient. Warmed IV fluids that are administered at very low flow rates can cool as they flow down the IV tubing to the patient. Often this heat loss is ignored. One prior art approach has been to simply heat the fluid to 41°C to try to overcome the loss for all flow rates.
In another aspect of fluid warming, most IV fluid warmers heat fluid through flexible plastic walls . Because these walls are inefficient in transferring heat, heaters are exposed to both sides of the disposable set. This requires inserting the disposable set into a slot or hinged clam shell configuration. Both of these designs do not allow the user to see the fluid passing through the heat exchanger. As these plastic walls are flexible, the pressure necessary for good heat transfer cannot be guaranteed as it is supplied only by the gravitational force of the IV fluid bag height. Cleaning of configurations with slots is difficult and typically requires special tools or even disassembly, such as in the case of blood spills.
One type of exemplary medical fluid warming system is described in US 2005-0008354. In this device, fluid passes along a generally serpentine fluid flow path through a removable/disposable heat exchange body. The heat exchange body is in thermal contact with a resistive film heater via thermally conductive layers interposed between the heat exchange body and the heater. Temperature sensors are provided that sense the temperature of the heat exchange body and of the heater.
SUMMARY OP THE INVENTION
In one aspect of the present invention, a fluid warming system includes a pair of sliding covers that maintains a removable heat exchange body in place in heat exchange communication with a heater assembly. The heat exchange body is pressed in place by the covers in the closed position to guarantee good thermal conductivity. Fluid passing through the heat exchange body remains visible to the user. The heat exchange body is easily inserted and removed by sliding the covers to a open position. The moving covers can double as user input mechanisms by turning the power on and off and muting alarms. The covers do not cover any indicators present on the heat exchange body. The covers can be readily removed for cleaning, and the covers can be used as a mounting mechanism.
In another aspect of the present invention, power to the heater can be increased or decreased to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient .
DESCRIPTION OF THE DRAWINGS The invention will be more fully understood from the following detailed description taken in conjunction with the accompanying drawings in which:
Fig. 1 is an isometric view of a fluid warming device illustrating slidable covers in a closed position according to the present invention;
Fig. 2 is an isometric view of the fluid warming device of Fig. 1 illustrating the slidable covers in a half closed position;
Fig. 3 is an isometric exploded view of the fluid warming device of Fig. 1 with the slidable covers in an open position and a disposable set removed;
Fig. 4 is an isometric view of a main body of the housing of the device of Fig. 1 with the slidable covers fully removed;
Fig. 5 is a plan view of the device of Fig. 2;
Fig. 6 is a cross sectional view taken along line A-A of Fig. 5;
Fig. 7 is a schematic view of a disposable set and heater assembly of the fluid warming device of Fig. 1;
Fig. 8 is a side view of a further embodiment of a fluid warming device illustrating gripping faces on the slidable covers;
Fig. 9 is a flow chart illustrating a system for adjusting power to a heater of a fluid warming device to accommodate heat loss in an IV tubing at low flow rates;
Fig. 10 is a graph illustrating heat loss across a disposable set heat exchange body and along a length of IV tubing and their combined heat losses,- and
Fig. 11 is a graph illustrating temperature loss for various lengths of IV tubing and various flow rates.
DETAILED DESCRIPTION OF THE INVENTION
A fluid warming device 10 according to the present invention is illustrated in Figs. 1-7. The fluid warming device includes a housing 12 having a main body 14 and two sliding covers 16. Within the housing, supported by the main body, are a removable heat exchange body 18 and a heater assembly 20. The sliding covers are independently slidable to a closed position in which they retain
the removable heat exchange body in place, as described more fully below. The slidable covers are preferably identical.
The removable heat exchange body 18 and the heating assembly 20 are illustrated schematically in Fig. 7. The heat exchange body, also called a disposable or removable set, includes an input port 22 connectable to an IV tubing line from a source of IV fluid, which may include an infusion pump. The disposable set also includes an output port 24 connectable to a further IV tubing line to deliver the IV fluid to the patient. Within the disposable set, the IV fluid flows along a flow path (not shown) having a serpentine or other suitable configuration between the input and output ports to optimize heat transfer to the fluid. See, for example, US Patent Pub. No. 2005-0008354, the disclosure of which is incorporated by reference herein. The disposable set is formed from any suitable material, such as aluminum, to facilitate heat transfer to the fluid flowing therein. When inserted in the housing with the sliding covers in a closed position, the disposable set is held in thermal contact with the heater assembly, so that heat transfer from the heater assembly to the disposable set causes heating of an IV fluid flowing therethrough.
The heater assembly 20 is affixed within the main body 14 of the housing 12. The heater assembly includes a heater 26 and one or more thermally conductive layers 28, 30 interposed between the disposable set and the heater. Preferably, the heater is an electrically powered resistive thin film heater. A power line 32 to the heater from a suitable power source is provided. Alternatively, the device may include a battery compartment or a connection to a battery pack, for example, for portable operation. Temperature sensors 34, 36 are provided that sense the temperature of the disposable set and of the heater. See, for example, US Patent Pub. No. 2005-0008354. The thermally conductive layers also electrically insulate the disposable set from the resistive heater. One thermally conductive layer 28 may suitably comprise a phase transition material, and the other thermally conductive
layer 30 may suitably comprise a material such as a graphite to optimize heat transfer between the heater and the disposable set. See, for example, US Patent Pub. No. 2005-0008354. It will be appreciated that other or further thermally conductive layers may be provided. The main body 14 includes a compartment 38 on one side to receive the disposable set 18 in contact with an exposed surface 40 of the uppermost thermally conductive layer 30.
As noted above, the heat exchange body or disposable or disposable set 18 is removable from the housing. The disposable set can be removed from the main body of the housing by sliding the two opposed sliding covers outwardly in opposite directions. In this manner, the removable set can be lifted out of the housing with the IV tubing still attached to the input and output connectors, without breaking the fluid path. Finger cutouts 42 may be provided for ease of grasping the disposable set in the main body.
Any suitable sliding mechanism to allow the covers to move axially into the closed position can be provided. In the embodiment shown, the main body 14 of the housing includes protruding longitudinal tracks 46 along two opposed longitudinal outer wall surfaces of the main body. See Fig. 5. The sliding covers include complementary longitudinal recesses 48 along inner wall surfaces that mate with the tracks and allow the covers to slide axially along the main body. When in the closed position, the sliding covers extend over the edges of the disposable set within the recess of the main body, thereby retaining the disposable set therein. See Fig. 1. The covers also compress the disposable set to the outermost thermally conducting surface 40 of the heater assembly. This compression provides the necessary pressure for proper heat transfer between the heater assembly and the disposable set. Preferably, the covers are retained in the closed position by frictional engagement with the disposable set Alternatively, any suitable latching or retaining mechanism may be provided.
Also, the covers 16 do not block the view of the bulk of the mid portion of the disposable set 18, allowing the operator to view the fluid passing through the disposable set. The disposable set is also keyed to the main body 14 in any suitable manner so that it fits within the compartment in the correct orientation. For example, one end 47 of the disposable set may be rounded to fit within an correspondingly rounded portion 49 of the compartment 38. The disposable set may include an arrow 50 thereon to provide an indication of the direction of flow, so that the disposable set is inserted in the housing in the correct orientation. The covers do not block this arrow. Also, the main body preferably includes indicator lights, such as LEDs, thereon. For example, one LED 52 may provide an indication of temperature at the output port, and another LED 54 may provide an indication that the heater is connected to the power source. The covers do not block these indicator lights either.
In one embodiment, the covers 16 can be maintained in two positions on the main body or can be removed fully from the main body. While on the main body, the covers can be in a fully closed position or an open position. The covers can include magnets or
Hall Effect devices or other proximity sensors that interface with a corresponding component within the main body to determine the positions of the covers and cause operation of any appropriate switches. In a further embodiment, the covers can be maintained in a third or intermediate, half closed, position on the main body, described further below.
More particularly, in the fully closed position, (see Fig. 1) , the covers 16 apply full pressure to the disposable set 18 to ensure good thermal contact with the heater assembly. In this position, the sliding covers can also be used to turn the power on to commence warming and/or to activate any audible or visible alarm (s) . In the half closed position (see Fig. 2) , the disposable set is still held in place by the covers, but warming is stopped, the audible alarm is silenced, and the visual indicators are
turned off. The status LED could be flashed in battery operation to inform the user that the warmer is connected to the battery and draining. When the covers are in the open position (see Fig. 3) , the disposable set 18 can be inserted and removed. No heating takes place, the audible alarm is silenced, and visual indicators are turned off. The status LED could be flashed in battery operation to inform the user that the heater is connected to the battery and draining.
Any suitable latching or retaining mechanism can be provided to retain the covers in the desired positions relative to the main body. For example, as shown in Figs. 5 and 6, recessed surfaces 62 are provided on the main body 14 that latch with corresponding tabs 64 on the covers in the open position, preventing the covers from readily coming off the main body. Also, the tabs 64 abut surfaces 63 to hold the covers in the closed position. Finger grips 68 are provided to aid in grasping the covers to push or pull them to the desired position. The closed (and power on) position can be indicated by arrows 70 and an adjacent "ON" marking on the covers. Similarly, the open (and power off) position can be indicated by arrows 72 and an adjacent "OFF" marking on the covers . The covers can be fully removed from the main body in any suitable manner, for example, by the insertion of a suitable tool, such as a screw driver or dime, to lift the tab 64 over the surfaces 62. Alternatively, a latching or retaining mechanism can be configured to release simply by the use of sufficient force. Removal of the covers allows the device to be readily cleaned. Alternatively, passageways in the interior surfaces of the covers and a water tight main body housing allow cold sterilization by dipping in a sterilization fluid without complete removal of the covers.
Referring to Fig. 8, the sliding covers 14 may include opposed faces 74 that include gripping teeth thereon to form gripping faces. The gripping faces can be used to grip hospital
clothing or bedding and hold the warmer in place to reduce stress on the IV line when the covers are fully closed.
In another aspect of the present invention, power to the heater can be increased or decreased to adjust the fluid temperature to ensure that the fluid is at an appropriate temperature when it reaches the patient. More particularly, some IV fluids that have been warmed are administered at very low flow rates. These fluids cool as they travel down the IV tubing to the patient. The greater the difference between ambient temperature and the fluid temperature, the greater the radiated heat losses from the IV tubing.
A suitable controller is provided to perform the calculations and communicate with the heater to make the desired adjustments. Heater power is determined by the difference between a target temperature (typically in the range of 39 to 41°C) , and the actual fluid temperature.
Referring to Fig. 9, the temperature drop across the heat exchanger is calculated (step 102) . This temperature drop is equal to the heater power divided by the thermal resistance of the heater assembly. The thermal resistance can be readily determined by one of skill in the art from the thickness, thermal conductivity and area of the materials between the heater and the fluid and stored as a constant.
Then, the controller calculates the temperature loss of the IV tubing to the environment (step 104) . First, the difference between the fluid target temperature and the ambient temperature is determined. The temperature loss is equal to this temperature difference multiplied by the radiation loss and divided by the heater power. The ambient temperature is measured by a suitable sensor located within the warming device in close contact with the housing, which is very close to ambient temperature. The radiation loss is a constant that is derived from experimentation with various lengths of the IV tubing and various flow rates . See Fig. 11.
Next, at step 106, the controller determines if the IV tubing loss is greater than 1°C. Also at step 106, the controller also determines if the total drop along the IV tubing and across the heat exchanger is greater than a drop limit. The drop limit is the maximum temperature that the fluid can be artificially raised so that the allowable surface temperature on the heat exchanger is not exceeded, for example, no greater than 30C from the desired target temperature. If the answer at step 106 is Yes, the actual fluid temperature is calculated at step 108 as the measured fluid output temperature minus the drop limit. If the answer at step 106 is No, the actual fluid temperature is calculated at step 110 as the fluid output temperature in the IV tubing drop minus the IV tubing drop (from step 102) minus the heat exchanger drop (from step 104) . Using the calculated value of the actual temperature, heater power is adjusted appropriately.
In this manner, heat loss along the IV tubing can be more efficiently controlled The system allows the fluid warming device to be located a bit farther from the infusion site and still deliver normothermic fluid. The invention is not to be limited by what has been particularly shown and described, except as indicated by the appended claims.
Claims
1. A fluid warming device comprising: a housing comprising a main body and a pair of covers, the covers axially slidable on the main body, and a heat exchange body receiving compartment in the main body; a heater assembly disposed within the main body; and a heat exchange body removably disposable in the compartment of the main body in contact with a heat conducting surface of the heater assembly, the heat exchange body containing a fluid flow line from a fluid input port to a fluid output port; wherein the covers are slidable axially on the main body to a closed position in which the covers press the heat exchanger into heat exchange communication with the heater assembly.
2. The fluid warming device of claim 1, wherein the covers contact edges of the heat exchange body in the closed position and leave a mid portion of the heat exchange body visible .
3. The fluid warming device of claim 1, wherein the covers are slidable to an open position from which the heat exchange body can be removed from or inserted into the compartment in the main body.
4. The fluid warming device of claim 3, wherein the heat exchange body can be removed from or inserted into the compartment while attached to IV tubing.
5. The fluid warming device of claim 1, wherein the covers are retained in the closed position by frictional engagement with the heat exchange body.
6. The fluid warming device of claim 1, wherein the covers are slidable to a half closed position in which the covers still retain the heat exchange body within the compartment in the main body.
7. The fluid warming device of claim 1, wherein the covers include a switch to activate power to the heater assembly when the covers are in the closed position.
8. The fluid warming device of claim 1, wherein the heat exchange body includes visible indicators thereon, and the covers do not block the visible indicators when in the closed position.
9. The fluid warming device of claim 1, wherein the covers are slidable on longitudinal tracks on the main body of the housing.
10. The fluid warming device of claim 1, wherein fluid flowing through the heat exchange body is visible.
11. The fluid warming device of claim 1, wherein the covers are slidable in opposite directions between a fully closed position and an open position.
12. The fluid warming device of claim 1, wherein the covers are fully removable from the main body.
13. The fluid warming device of claim 1, wherein the covers are retained on the main body by a retaining mechanism.
14. The fluid warming device of claim 13, wherein the retaining mechanism comprises complementary latching surfaces on the covers and the main body.
15. A fluid warming system to minimize heat loss through IV tubing to a patient, comprising: a) determining a temperature drop across a heat exchange body of an IV fluid warming device; b) determining a temperature drop of the IV tubing to the environment, the IV tubing extending from the IV fluid warming device to a patient; c) determining if the temperature drop along the IV tubing is greater than a determined temperature limit; d) determining if the total temperature drop along the IV tubing and across the heat exchange body is greater than a determined drop limit; e) if the determined values from step c) and step d) are greater than their respective limits, determining the actual fluid temperature as a fluid output temperature minus the drop limit; f) if either of the determined values from step c) and step d) are not greater than their respective limits, determining the actual fluid temperature as a fluid output temperature minus the heat exchanger temperature drop; and g) adjusting power to the heat exchanger to achieve the desired output temperature.
16. The fluid warming system of claim 15, wherein the temperature drop across the heat exchanger in step a) is determined by dividing heater power of a heater assembly that heats the heat exchange body by the thermal resistance of the heater assembly.
17. The fluid warming system of claim 15, wherein the temperature drop of the IV tubing in step b) is determined by determining the difference between a fluid target temperature and ambient temperature, multiplying this difference by a radiation loss constant to get a result, and dividing the result by heater power of a heater assembly that heats the heat exchange body.
18. The fluid warming system of claim 15, wherein the determined temperature limit of step c) is 1°C.
19. The fluid warming system of claim 15, wherein the determined drop limit of step d) is a maximum temperature to which the IV fluid can be heated.
20. the fluid warming system of claim 19, wherein the maximum temperature is 30C above the desired temperature.
21. The fluid warming system of claim 15, wherein the fluid output temperature is measured by a temperature sensor on the IV fluid warming device.
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2008503073A JP4981024B2 (en) | 2005-03-21 | 2006-03-21 | Intravenous fluid heating system |
EP06739047.6A EP1868547B1 (en) | 2005-03-21 | 2006-03-21 | Intravenous fluid warming system |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US66385705P | 2005-03-21 | 2005-03-21 | |
US60/663,857 | 2005-03-21 |
Publications (2)
Publication Number | Publication Date |
---|---|
WO2006102260A2 true WO2006102260A2 (en) | 2006-09-28 |
WO2006102260A3 WO2006102260A3 (en) | 2007-11-22 |
Family
ID=37024491
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US2006/010099 WO2006102260A2 (en) | 2005-03-21 | 2006-03-21 | Intravenous fluid warming system |
Country Status (4)
Country | Link |
---|---|
US (4) | US7865072B2 (en) |
EP (1) | EP1868547B1 (en) |
JP (4) | JP4981024B2 (en) |
WO (1) | WO2006102260A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7846130B2 (en) | 2007-03-13 | 2010-12-07 | Quality In Flow Ltd. | Portable intravenous fluid heating system |
WO2018140414A1 (en) * | 2017-01-24 | 2018-08-02 | Vyaire Medical, Inc. | Intravenous fluid warming system |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP4981024B2 (en) * | 2005-03-21 | 2012-07-18 | エンジニヴィティー, エルエルシー | Intravenous fluid heating system |
CA2754773C (en) | 2009-03-09 | 2017-06-13 | Thermedx, Llc | Surgical fluid management system having default operating parameters associated with a plurality of medical procedures |
US9474848B2 (en) | 2009-03-09 | 2016-10-25 | Thermedx, Llc | Fluid management system |
US20110202034A1 (en) * | 2010-02-17 | 2011-08-18 | Estill Medical Technologies, Inc. | Modular medical fluid heating apparatus |
US8690842B2 (en) | 2010-09-27 | 2014-04-08 | Estill Medical Technologies, Inc. | Electrical power source for an intravenous fluid heating system |
WO2013040197A1 (en) * | 2011-09-13 | 2013-03-21 | Tautona Group Lp | Syringe with temperature modulation capabilities |
BR112014008325A2 (en) * | 2011-10-13 | 2017-04-18 | Mequ Aps | infusion fluid heater |
US9770541B2 (en) | 2014-05-15 | 2017-09-26 | Thermedx, Llc | Fluid management system with pass-through fluid volume measurement |
EP3268071A1 (en) | 2015-03-10 | 2018-01-17 | Life Warmer Inc. | Thermic infusion system |
EP3069745B1 (en) | 2015-03-16 | 2023-12-27 | The Surgical Company International B.V. | Fluid warming system with biased layers |
WO2017029043A1 (en) * | 2015-08-14 | 2017-02-23 | Mequ A/S | Infusion fluid warmer comprising printed circuit board heating elements |
IL242942A0 (en) * | 2015-12-03 | 2016-04-21 | Gershon Goldenberg | Thermal control of liquids for transcutaneous delivery |
US10722660B2 (en) * | 2016-05-17 | 2020-07-28 | The Surgical Company International B.V. | Fluid warming system |
US11707580B2 (en) | 2017-09-08 | 2023-07-25 | Life Warmer Inc. | Thermic infusion system dry tube detector |
WO2020264084A1 (en) | 2019-06-27 | 2020-12-30 | Boston Scientific Scimed, Inc. | Detection of an endoscope to a fluid management system |
CN114945392A (en) | 2019-11-08 | 2022-08-26 | 瑟梅德斯有限责任公司 | Fluid management system and method |
CN113041158A (en) * | 2021-03-02 | 2021-06-29 | 烟台毓璜顶医院 | Continuous heating device during nasal feeding |
Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4019020A (en) | 1975-08-13 | 1977-04-19 | The Gorman-Rupp Company | Controlled temperature fluid heater |
DE3731189A1 (en) | 1986-10-07 | 1988-04-21 | Stihler Medizintechnik Gmbh | Device for warming infusion and transfusion solutions |
US4847470A (en) | 1987-12-14 | 1989-07-11 | Bakke Allan P | Electric blood warmer utilizing metallic ribbon flow cartridge and low thermal mass heating units |
WO2000053246A1 (en) | 1999-03-09 | 2000-09-14 | Augustine Medical, Inc. | Iv fluid warming system with detection of presence and alignment of cassette |
US20050008354A1 (en) | 2003-07-09 | 2005-01-13 | Enginivity Llc | Medical fluid warming system |
Family Cites Families (35)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3443060A (en) * | 1967-02-09 | 1969-05-06 | Gorman Rupp Co | Thermostatically controlled electric blood heating apparatus |
US3590215A (en) * | 1969-03-27 | 1971-06-29 | Thermolyne Corp | Clinical fluid warmer |
JPS54109291A (en) * | 1978-02-16 | 1979-08-27 | Genshirou Ogawa | Heater structure for instillation liquid* transfusion blood or like |
US4464563A (en) * | 1981-08-28 | 1984-08-07 | Jewett Warren R | Intravenous fluid warmer |
JPS59124887U (en) * | 1983-02-03 | 1984-08-22 | 三菱電機株式会社 | heat exchange equipment |
JPS6164261A (en) * | 1984-09-06 | 1986-04-02 | 小川 源之郎 | Warmer of dripping liquid and transfusion liquid |
US4680445A (en) * | 1984-09-06 | 1987-07-14 | Genshiro Ogawa | Electronically-controlled heating device for infusion liquids |
US4735609A (en) * | 1986-07-24 | 1988-04-05 | Medical Industrial Technologies, Inc. | IV fluid warmer |
DE3636995A1 (en) * | 1986-10-30 | 1988-05-11 | Fresenius Ag | METHOD AND DEVICE FOR EXTRACTING HEAT FROM BLOOD IN THE EXTRACORPORAL CIRCUIT |
NL8701233A (en) * | 1987-05-22 | 1988-12-16 | Medistad Holland | BLOOD HEATER. |
US5250032A (en) * | 1991-12-13 | 1993-10-05 | Spectralogic, Inc. | Heater for in vivo blood infusion |
US5319170A (en) * | 1992-10-20 | 1994-06-07 | Belmont Instrument Corporation | Induction fluid heater utilizing a shorted turn linking parallel flow paths |
US5420962A (en) * | 1993-10-25 | 1995-05-30 | Bakke; Allan P. | Convection blood warming system with disposable flattened tube envelope having vent incorporating a hydrophobic filter |
JP3659726B2 (en) * | 1996-03-08 | 2005-06-15 | テルモ株式会社 | Automatic peritoneal dialysis device with turbidity measurement function and circuit for peritoneal dialysis |
US6047108A (en) * | 1996-10-01 | 2000-04-04 | Baxter International Inc. | Blood warming apparatus |
AU6683498A (en) | 1997-03-03 | 1998-09-22 | Medical Solutions, Inc. | Method and apparatus for pressure infusion and temperature control of infused liquids |
US6467953B1 (en) * | 1999-03-30 | 2002-10-22 | Medical Solutions, Inc. | Method and apparatus for monitoring temperature of intravenously delivered fluids and other medical items |
US7041941B2 (en) | 1997-04-07 | 2006-05-09 | Patented Medical Solutions, Llc | Medical item thermal treatment systems and method of monitoring medical items for compliance with prescribed requirements |
DE19733278C2 (en) * | 1997-08-01 | 1999-11-11 | Storz Endoskop Gmbh | Pressure container for pressurizing a flexible bag which is accommodated therein and filled with a medical liquid |
US6175688B1 (en) * | 1998-07-10 | 2001-01-16 | Belmont Instrument Corporation | Wearable intravenous fluid heater |
JP3520215B2 (en) * | 1999-02-08 | 2004-04-19 | シュアメド株式会社 | Drug enema device |
EP1157710A1 (en) * | 1999-02-10 | 2001-11-28 | Tomio Ohta | Cancer therapeutic agent supply device |
US6788885B2 (en) * | 2000-09-01 | 2004-09-07 | Michael Mitsunaga | System for heating instillation or transfusion liquids |
US6336003B1 (en) * | 2000-09-01 | 2002-01-01 | Automatic Medical Technologies, Inc. | Max one I.V. warmer |
US6423268B1 (en) | 2001-01-16 | 2002-07-23 | Luther M. King | Blood heating system with mutually exclusive relay-controlled heat exchangers |
US6539172B2 (en) * | 2001-01-31 | 2003-03-25 | Kabushiki Kaisha Sanko | Fluid heating device and cartridge for the same |
US6643454B1 (en) * | 2001-03-20 | 2003-11-04 | Alpha-Western Corporation | Bath temperature maintenance heater |
JP2003135599A (en) * | 2001-11-02 | 2003-05-13 | Akira Funasaka | Tube heater |
US8226605B2 (en) * | 2001-12-17 | 2012-07-24 | Medical Solutions, Inc. | Method and apparatus for heating solutions within intravenous lines to desired temperatures during infusion |
US7394976B2 (en) * | 2003-03-25 | 2008-07-01 | Arizant Healthcare Inc. | Fluid warming cassette and system capable of operation under negative pressure |
US6921270B2 (en) * | 2003-06-11 | 2005-07-26 | Cinch Connectors, Inc. | Electrical connector |
DE202004020709U1 (en) * | 2004-05-29 | 2005-12-22 | WWT Technischer Gerätebau GmbH | Fluid warming bag, especially blood warming bag, has insertion edge installed on second boundary edge, and fluid guiding seam is formed by connection of plastic films in region of throughflow volume |
US7163031B2 (en) * | 2004-06-15 | 2007-01-16 | Mallinckrodt Inc. | Automated dispensing system and associated method of use |
US7164852B2 (en) * | 2005-01-11 | 2007-01-16 | Gaymar Industries, Inc. | Fluid reservoir with integrated heater |
JP4981024B2 (en) * | 2005-03-21 | 2012-07-18 | エンジニヴィティー, エルエルシー | Intravenous fluid heating system |
-
2006
- 2006-03-21 JP JP2008503073A patent/JP4981024B2/en active Active
- 2006-03-21 EP EP06739047.6A patent/EP1868547B1/en active Active
- 2006-03-21 WO PCT/US2006/010099 patent/WO2006102260A2/en active Application Filing
- 2006-03-21 US US11/385,085 patent/US7865072B2/en active Active
-
2011
- 2011-01-03 US US12/983,420 patent/US8150244B2/en active Active
- 2011-12-28 JP JP2011288194A patent/JP2012091011A/en active Pending
-
2012
- 2012-04-03 US US13/438,294 patent/US8660415B2/en active Active
-
2014
- 2014-02-24 US US14/188,473 patent/US10022507B2/en active Active
- 2014-04-10 JP JP2014080966A patent/JP2016119921A/en active Pending
-
2017
- 2017-08-24 JP JP2017161274A patent/JP2018008080A/en active Pending
Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4019020A (en) | 1975-08-13 | 1977-04-19 | The Gorman-Rupp Company | Controlled temperature fluid heater |
DE3731189A1 (en) | 1986-10-07 | 1988-04-21 | Stihler Medizintechnik Gmbh | Device for warming infusion and transfusion solutions |
US4847470A (en) | 1987-12-14 | 1989-07-11 | Bakke Allan P | Electric blood warmer utilizing metallic ribbon flow cartridge and low thermal mass heating units |
WO2000053246A1 (en) | 1999-03-09 | 2000-09-14 | Augustine Medical, Inc. | Iv fluid warming system with detection of presence and alignment of cassette |
US20050008354A1 (en) | 2003-07-09 | 2005-01-13 | Enginivity Llc | Medical fluid warming system |
Non-Patent Citations (1)
Title |
---|
See also references of EP1868547A4 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7846130B2 (en) | 2007-03-13 | 2010-12-07 | Quality In Flow Ltd. | Portable intravenous fluid heating system |
WO2018140414A1 (en) * | 2017-01-24 | 2018-08-02 | Vyaire Medical, Inc. | Intravenous fluid warming system |
Also Published As
Publication number | Publication date |
---|---|
JP4981024B2 (en) | 2012-07-18 |
US20060222350A1 (en) | 2006-10-05 |
US8660415B2 (en) | 2014-02-25 |
EP1868547A2 (en) | 2007-12-26 |
JP2016119921A (en) | 2016-07-07 |
US8150244B2 (en) | 2012-04-03 |
EP1868547B1 (en) | 2020-10-21 |
US20140169775A1 (en) | 2014-06-19 |
US10022507B2 (en) | 2018-07-17 |
WO2006102260A3 (en) | 2007-11-22 |
US7865072B2 (en) | 2011-01-04 |
US20110098642A1 (en) | 2011-04-28 |
JP2012091011A (en) | 2012-05-17 |
JP2008532728A (en) | 2008-08-21 |
JP2018008080A (en) | 2018-01-18 |
US20120203176A1 (en) | 2012-08-09 |
EP1868547A4 (en) | 2014-08-13 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US8150244B2 (en) | Intravenous fluid warming system | |
US7158719B2 (en) | Medical fluid warming system | |
US5875282A (en) | Medical apparatus for warming patient fluids | |
AU2018213181C1 (en) | Intravenous fluid warming system | |
US20070142773A1 (en) | Methods and system for warming a fluid | |
US9931279B2 (en) | Neonatal fluid tubing heater | |
US20090319011A1 (en) | Method and system for warming or cooling a fluid | |
CA2651417A1 (en) | System and disposable for direct heating for infusate and intravenous fluids and a method therefor | |
EP2432443A1 (en) | A flexible fluid storage and warming bag and a fluid storage and warming system | |
EP1462137A1 (en) | Multiple plate fluid warmer unit in combination with interconnected fluid warming bags | |
EP2950847B1 (en) | Medical infusion fluid heat exchange apparatus and warming systems | |
WO2018015300A1 (en) | Medical tempering device and method for tempering infusion fluids |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
121 | Ep: the epo has been informed by wipo that ep was designated in this application | ||
ENP | Entry into the national phase |
Ref document number: 2008503073 Country of ref document: JP Kind code of ref document: A |
|
NENP | Non-entry into the national phase |
Ref country code: DE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 2006739047 Country of ref document: EP |
|
NENP | Non-entry into the national phase |
Ref country code: RU |