Frozen bag of liquid thawer utilizing heat at ambient temperature

Abstract

The present invention provides a bag thawer 10 for thawing at least one bag of frozen liquid. Generally, the frozen bags of liquid are I.V. bags 42 containing medical solutions. The bag thawer 10 provides an upper contact plate 12 sized to contain a first quantity of heat at room temperature and a lower contact plate 14 sized to contain a second quantity of heat at room temperature. The total heat contained in the upper and lower contact plates 12, 14 is sufficient to thaw the frozen I.V. bags 42 without applying additional heat to I.V. bag 42 or rewarming contact plates 12, 14. The upper and lower contact plates 12, 14 are hinged together by a hinge 16. The upper contact plate 12 is biased by spring 36 towards the lower contact plate 14. In one alternative embodiment, a pair of heaters 116, 118 are placed in contact with the contact plates 112, 114 to maintain the contact plates 112, 114 at approximately room temperature.

What is claimed is: 
     
       1. A device adapted to thaw frozen liquid contained in at least one bag comprising: an upper contact plate having a size such that when the upper contact plate is at room temperature the upper contact plate contains a first quantity of room temperature heat;   a lower contact plate having a size such that when the lower contact plate is at room temperature the lower contact plate contains a second quantity of room temperature heat, the upper contact plate and the lower contact plate being sized such that the first quantity of room temperature heat combined with the second quantity of room temperature heat is capable of completely thawing the frozen liquid;   a hinge movably connecting the upper contact plate to the lower contact plate at a hinged location; and   means attached to the upper contact plate and the lower contact plate for biasing the upper contact plate towards the lower contact plate.   
     
     
       2. The device of claim 1 wherein the means for biasing comprises: a pair of rocker arms, each rocker arm pivotally attached to the upper contact plate;   a clamp handle attached to the pair of rocker arms; and   a pair of springs, each spring having a first spring end and a second spring end, the first spring end removably attached to the lower contact plate and the second spring end removably attached to the rocker arm.   
     
     
       3. The device of claim 2 wherein each rocker arm is pivotal from a first rocker arm position to a second rocker arm position, in the first rocker arm position each spring has a first biasing force between the upper contact plate and the lower contact plate, in the second rocker arm position each spring has a second biasing force between the upper contact plate and the lower contact plate, the second biasing force being greater than the first biasing force. 
     
     
       4. The device of claim 3 wherein the first biasing force of each spring is approximately 0 lbs. 
     
     
       5. The device of claim 3 wherein the second biasing force of each spring generates a combined biasing force of approximately 15 lbs. to 30 lbs. 
     
     
       6. The device of claim 1 wherein the hinge allows the upper contact plate to pivot at the hinged location and allows the upper contact plate to move away from the lower contact plate at the hinged location. 
     
     
       7. The device of claim 6 further comprising a projection connected to the upper contact plate at the hinged location, and wherein the lower contact plate defines a seat at the hinged location, the projection and the seat being adapted to cooperate with each other to form the hinge. 
     
     
       8. The device of claim 7 wherein the projection extends across a width of the upper contact plate and the seat extends across a width of the lower contact plate. 
     
     
       9. The device of claim 1 further comprising means for mounting the lower contact plate on a wall. 
     
     
       10. The device of claim 1 wherein the means for biasing generates a biasing force of approximately 15 lbs. to 30 lbs. 
     
     
       11. The device of claim 1 further comprising at least one foot attached to the lower contact plate for supporting the lower contact plate on a table. 
     
     
       12. The device of claim 11 wherein the foot is removable from the lower contact plate and the device further comprises means for mounting the lower contact plate on a wall. 
     
     
       13. The device of claim 12 wherein the means for mounting comprises at least one bracket attached to the lower contact plate. 
     
     
       14. The device of claim 12 wherein the means for mounting comprises at least one support recess adapted to cooperate with a bracket attached to a wall. 
     
     
       15. The device of claim 1 wherein the frozen liquid is contained in at least one I.V. bag. 
     
     
       16. The device of claim 1 wherein the room temperature is a range of approximately 72° F.-75° F. 
     
     
       17. A method for thawing frozen liquid contained in at least one bag comprising the steps of: providing an upper contact plate having a size such that when the upper contact plate is at room temperature the upper contact plate contains a first quantity of room temperature heat;   providing a lower contact plate having a size such that when the lower contact plate is at room temperature the lower contact plate contains a second quantity of room temperature heat, the upper contact plate and the lower contact plate being sized such that the first quantity of room temperature heat combined with the second quantity of room temperature heat is capable of completely thawing the frozen liquid;   placing at least one bag of frozen liquid in contact with the lower contact plate and the upper contact plate;   biasing the upper contact plate towards the lower contact plate; and   transferring heat from the lower contact plate and the upper contact plate to the bag of frozen liquid at a location where the contact plates contact the bag to generate a thawed bag of liquid.   
     
     
       18. The method of claim 17 further comprising the steps of: removing the thawed bag of liquid from contact with the lower contact plate and the upper contact plate;   contacting the lower and upper contact plates with room temperature air;   transferring heat from the room temperature air to the upper and lower contact plates at a location where the air contacts the contact plates; and,   heating the lower contact plate and the upper contact plate to room temperature with the room temperature air.   
     
     
       19. The method of claim 17 wherein the step of biasing further comprises the steps of: pivoting a rocker arm attached to the upper contact plate; and   stretching a spring attached to the rocker arm and the lower contact plate.   
     
     
       20. A bag thawer adapted to thaw frozen liquid contained in at least one bag having opposite sides comprising: a pair of contact plates, each contact plate having a first side capable of being in contact with one of the opposite sides of the bag containing the frozen liquid;   a pair of heaters, each heater in direct contact with one of the contact plates on a second side of each contact plate opposite from the first sides;   a pair of back plates, each back plate coupled to one of the heaters on a side of each heater opposite from the contact plates;   a heater control electrically connected to the pair of heaters and limiting a maximum temperature of each of the heaters such that the contact plates reach a maximum contact plate temperature of approximately room temperature; and   means coupled to the pair of contact plates for biasing the pair of contact plates towards the bag.   
     
     
       21. The bag thawer of claim 20 wherein the room temperature is a range of approximately 72° F. -75° F. 
     
     
       22. The bag thawer of claim 20 further comprising a pair of thermocouples electrically connected to the heater control, each one of the thermocouples contacting one of the contact plates to sense the temperatures of the contact plates. 
     
     
       23. The bag thawer of claim 20 further comprising: a base for supporting the bag thawer on a table, the base having a bottom side facing the table and a top side facing away from the table; and   a resilient support flexibly supporting one of the pair of back plates on the top side of the base.   
     
     
       24. The bag thawer of claim 23 wherein the resilient support comprises a set of springs. 
     
     
       25. The bag thawer of claim 23 wherein the back plate supported by the resilient support is a lower back plate and the other back plate is an upper back plate, the bag thawer further comprising a hinge attached to the base and the upper back plate; the hinge allowing the pair of contact plates to be separated such that the I.V. bag can be removed from contact with the contact plates; and   wherein the means for biasing comprises a set of clamps, each clamp attached to the base and to the upper back plate.   
     
     
       26. The device of claim 20 wherein the frozen liquid is contained in at least one I.V. bag. 
     
     
       27. A method for thawing a frozen liquid contained in at least one bag having opposite sides comprising the steps of: providing a pair of contact plates at room temperature, each contact plate having a first side capable of being in contact with one of the opposite sides of the bag;   biasing the contact plates towards the bag;   transferring heat at room temperature from the contact plates to the bag;   providing a pair of heaters, each heater being in direct contact with one of the contact plates on a second side of each contact plate opposite from the first sides;   maintaining the temperature of the contact plates at room temperature by transferring heat from the heaters to the contact plates; and   controlling the temperature of the heaters to prevent the liquid contained in the bag from reaching a temperature above room temperature.   
     
     
       28. The method of claim 27 wherein the step of controlling the temperature of the heaters comprises the step of sensing the temperature of the heaters with a thermocouple. 
     
     
       29. The method of claim 27 wherein the step of providing a pair of contact plates at room temperature in contact with opposite sides of the bag comprises the step of flexibly supporting one contact plate for parallel and unparallel alignment of the contact plates.