intravenous cooling system to induce mild hypothermia april 10 th, 2007 steve huppman jermaine...
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Intravenous Cooling System to Induce Mild Hypothermia
April 10th, 2007
Steve Huppman
Jermaine Johnson
Sylvia Kang
Erin Wacker
University of PittsburghSenior Design – BioE 1160-1161
Cardiac Arrests
• On average EMS treat 107,000 – 240,000 out-of-hospital cardiac arrests per year1
• Cardiac arrest with no blood flow for a period >5 min cerebral brain damage due to ischemia will occur
• In 2006, AHA estimates 163,221 out-of- hospital cardiac arrests annually in US1
1. American Heart Association. Heart Disease and Stroke Statistics – 2006 Update. www.americanheart.org 2006
Therapeutic Hypothermia
• Therapeutic hypothermia in literature since 1950’s but widely ignored until 2002
• ILCOR recommended unconscious cardiac arrest patients should be cooled between 32 – 34 °C for 12-24 hrs2
• Cooling the body to this temperature immediately after cardiac arrest has the potential improve the neurological outcome and reduce the mortality rate
2. Nolan, JP. Morley, PT. Vanden Hoek, TL, et al. Therapeutic hypothermia after cardiac arrest: an advisory statement by the advanced life support task force of the International Liaison Committee on Resuscitation. Resuscitation. Vol. 57, No. 3, 2003
Project Objectives
• Design a device to induce mild hypothermia in a person that has suffered cardiac arrest no later than 5 min after blood flow has ceased
• Will do so by designing an IV cooling system that will attach between a saline bag and the IV injection site on the patient
• Device should be able to cool saline to a temperature 10°C below room temperature for a period of 15 min
• Additional external cooling will occur as the device is placed on the chest of the patient
Physical and Operational Characteristics
• Able to begin the process of inducing mild hypothermia (34 -36°C)
• Disposable, portable and light weight (<2 lb.)
• Able to stay cold (<15°C) for 15 min
• Capable to function at normal room temperature (22.5°C)
• Placed on the top of the patient’s chest
Must be
Market Size
• To be used by EMS and other emergency first responders to help cardiac arrest victims
• 107,000 – 240,000 cardiac arrests treated per year out of the hospital3
• We envision the device can be used in all emergency vehicles
• May also be used to help victims suffering from heat-related illness
• Firefighters
3. American Heart Association. Heart Disease and Stroke Statistics – 2006 Update. www.americanheart.org 2006
Competitive Analysis• Celsius Control System™ by Innercool
Therapies
PortabilityAnd
Emergency
Usage
TemperatureControllability
Effectiveness
ofCooling
Price
IV CoolingSystem
√ √ √
Celsius Control
System√ √(US Patent 6096068, Innercool Therapies, Inc, 1998)
Competitive Analysis (con’t)
• Cooling Body Garment• Receives gaseous coolant from a supply
• Cooling garment applies the coolant directly to the skin of the patient
• As the coolant moves away from the patient, it carries the heat away, thereby cooling the patient
PortabilityAnd
Emergency
Usage
TemperatureControllability
Effectiveness
ofCooling
Price
IV CoolingSystem
√ √ √
Cooling BodyGarment
(US Patent 7056282, Medtronic, Inc, 2003)
Competitive Analysis (con’t)• Hypothermia Induction Device
• Recirculates blood through an extracorporeal circuit using a venous access
• The blood can be cooled and/or treated before reentry to the vascular system
PortabilityAnd
EmergencyUsage
TemperatureControllabilit
y
Effectiveness
ofCooling
Price
IV CoolingSystem
√ √ √
Hypothermia
InductionDevice
√ √
(US Patent 2006/0041217, 2006)
Marketing Suggestions
• Big market on induction of hypothermia
• Many previous methods and devices have been developed on this topic
• Focused on either precise internal cooling or external cooling only
• Portable internal cooling systems used in emergency situations have been rarely studied
Theoretical Design Considerations
• Conservation balance for mass through a tube • Test subject
• 160 pounds• 50 liters of body fluid (water)• Starting temperature of 37°C• Ending temperature of 34°C
• Ambient conditions• Room temperature of 22.5°C• Ammonium nitrate solution temperature of
4°C
• Want to infuse 2 liters• Infused saline needs to be -40°C
• Infused saline enters at 10°C• Need to infuse 6.3 liters
• This would double blood volume
*Reconsider product specifications*
Theoretical Design Considerations
Design Alternatives
• Design #1 tubing in series• Standard IV tubing
• Saline temp 14.9°C• Flow rate 0.5 ml/sec • 60 mins to infuse 2 L.
• Minivolume IV tubing• Saline temp 14.7°C• Flow rate 0.1 ml/sec • 300 mins to infuse 2 L.
Intravenous Fluid
Cold Fluid to Patient
Chemical Ice-Bag with Internal Tubing
*Insufficient cooling and flow rate*
Design Alternatives
• Design #2 tubing in parallel
32 tubes across 2 rows of 16
*Pressure drop too large*
• Tubing in parallel
• Standard IV tubing• Average saline temperature of 10°C
• Flow rate of 1 ml/sec 30 mins to infuse 2 L.
• Using the same mass conservation as before
• Infusing 2 liters of saline at 10°C
• Ammonium nitrate solution temp of 4°C
Design Description
*Will decrease body temp by ~1.5°C*
Engineering Technologies/Methodologies
• Manifold designed in SolidWorks
• Manufactured by hand• Manifold: Dacron (6”)• Tubes: PVC, size of
standard IV tubing(10”)• 1 Ammonium Nitrate :
2 Water*
Design Weaknesses
• Infusion of 2 L takes 30 mins but device is only used for 15 min
• Device needs to be primed saline bag becomes a part of the device
• Measured average temperature of water do not know temp at which saline is entering
Risk Classification
Risk Classification: 4 = acceptable, 1 = unacceptable
OccurrenceConsequences
Negligible Marginal Critical Catastrophic
Frequent 2 1 1 1
Probable 3 2 1 1
Occasional 3 3 2 1
Remote 4 3 3 2
Improbable 4 4 3 3
Incredible 4 4 4 4
Initial Hazard Analysis
Hazard Risk Class
Ammonium Nitrate Entering Blood Stream Due To Entry Into Saline LineIndividuals Involved:
Patient
1
Skin Irritation Due To Casing Malfunction (i.e. Tear, Leakage from Seals, etc)
Individuals Involved:Emergency Response Personnel
Patient
3
Premature Activation of Ammonium NitrateIndividuals Involved:
None
4
Regulation• Class II Medical Device C
• Predicate Devices: CFR Title 21 – 510(k)
• Cooling Systems• Subpart F – Part 870 - Cardiovascular Therapeutic Devices
• 870.5900 Thermal Regulation System Class: II
• Subpart F – Part 890 - Physical Medicine Therapeutic Devices• 880.5540 Tubing, Fluid Delivery Class: II
• Intravenous Tubing• Subpart F – Part 880 - General Medicine Devices
• 890.5710 Pack, Hot or Cold, Disposable Class: I
• 890.5720 Pack, Hot or Cold, Water Circulating Class: II
Team Member Contributions
• Erin• Theoretical design considerations
• Jermaine• Literature review, FDA regulations
• Steve• Ordering supplies, testing of prototype
• Sylvia• Marketability, competitive analysis
Acknowledgements
Thanks to• The generous gift of Drs. Hal Wrigley and
Linda Baker• Department of Bioengineering• Our mentor, Dr. James Menegazzi• Andy Holmes• Dr. Jack Patzer II• Dr. Mark Gartner