Heated LavageHeated Lavage

Joe McFerron, Justin Miller, Joe McFerron, Justin Miller, and and

Ashley DanicicAshley Danicic

Dr. Dinakar Golla, M.DDr. Dinakar Golla, M.DLinda Huckenstein , R.NLinda Huckenstein , R.N

Background InformationBackground Information Lavages are most frequently Lavages are most frequently

used to remove debris from an used to remove debris from an organ or cavity with repeated organ or cavity with repeated injections of a solutioninjections of a solution. .

The solution (saline) is often The solution (saline) is often heated heated

to increase circulation to to increase circulation to the area the area

reduce the risk of reduce the risk of infectioninfection

and to increase the and to increase the comfort of the patientcomfort of the patient

MethodsMethods

HeatHeat ExchangerExchanger

BulkyBulky

More expensiveMore expensive

Must rely on internal Must rely on internal pump in the heat pump in the heat exchanger to propel the exchanger to propel the solution to the lavage solution to the lavage device.device.

MicrowaveMicrowave

cannot control the cannot control the temperature of solutiontemperature of solution

PVC IV bag deforms at PVC IV bag deforms at 135-180 degrees F135-180 degrees F

Solution immediately Solution immediately begins to cool, must be begins to cool, must be reheated again reheated again

Group GoalsGroup Goals To design a device that when mounted onto the IV bag, To design a device that when mounted onto the IV bag,

can control and measure the temperature of the solutioncan control and measure the temperature of the solution

Heater must heat solution to desired temperature, it must Heater must heat solution to desired temperature, it must be flexible, small, and capable of heating solution quicklybe flexible, small, and capable of heating solution quickly

Choose insulation for heater which is resistant to Choose insulation for heater which is resistant to chemicals, water, and other liquids.chemicals, water, and other liquids.

The thermocoupleThe thermocouple must be small enough to fit into one of the IV’s ports. must be small enough to fit into one of the IV’s ports.

(~0.24 in),(~0.24 in),

capable of immersion in fluids, but also must not let solution leak capable of immersion in fluids, but also must not let solution leak from port.from port.

Fast and accurate responseFast and accurate response

hermetically sealedhermetically sealed

Individual GoalsIndividual Goals Research heater optionsResearch heater options Etched Foil-etched foil resistive elementEtched Foil-etched foil resistive element

Pros: more economical in small heaters, thin, very Pros: more economical in small heaters, thin, very flexible, transfer heat more efficiently over larger surface flexible, transfer heat more efficiently over larger surface area, heaters stay cooler to the touch, run higher area, heaters stay cooler to the touch, run higher wattages, insulation life is 10x greater, uniform heat wattages, insulation life is 10x greater, uniform heat patterns, patterns,

Cons: heating element less durable, not as economical if Cons: heating element less durable, not as economical if manufacturedmanufactured

Resistance Wire- wire elements, Resistance Wire- wire elements, Pros: more economical in large sizes/ manufacturing, Pros: more economical in large sizes/ manufacturing,

durable, lower leakage current, withstand repeated durable, lower leakage current, withstand repeated flexing, uniform heat patternsflexing, uniform heat patterns

Cons: thick , reduced watt densitiesCons: thick , reduced watt densities Research insulation optionsResearch insulation options

KaptonKapton Silicone RubberSilicone Rubber All-Polyimide (AP)All-Polyimide (AP) MicaMica

Update Design history fileUpdate Design history file

Achievements to DateAchievements to Date Procured 2 lavages for testingProcured 2 lavages for testing Designed heaterDesigned heater

determined approximate heater size, temperature determined approximate heater size, temperature range, Max. resistance density, power, lead locations range, Max. resistance density, power, lead locations and sizeand size

Heater will be galvanized to mating parts.Heater will be galvanized to mating parts. 5 minute warm up time5 minute warm up time Heater wraps around circumference of IV bag and Heater wraps around circumference of IV bag and

clamped into place.clamped into place. Contacted several custom heater manufacturers Contacted several custom heater manufacturers Considering thermocouple Considering thermocouple Selected Kapton insulator Selected Kapton insulator

Excellent dielectric strength, resistant to most acids, Excellent dielectric strength, resistant to most acids, solvents, and bases, can be made for immersion in solvents, and bases, can be made for immersion in fluids.fluids.

Completed heater designCompleted heater design Maximum heater Maximum heater

thickness (with foil thickness (with foil backing):backing): Over element: 0.4 mmOver element: 0.4 mm Over Leads: 1.4 mmOver Leads: 1.4 mm

Kapton Insulator:Kapton Insulator: 0.03-0.05 mm0.03-0.05 mm Temperature range Temperature range

(-200 C -200 (-200 C -200 C)C)

Lead Wires: Lead Wires: 0.141 mm^20.141 mm^2

Work to DoWork to Do Finite Element Analysis on Heater in Finite Element Analysis on Heater in

CosmosFloWorks CosmosFloWorks (This week)(This week)

Decide on ThermocoupleDecide on Thermocouple (Mid February)(Mid February)

Decide temperature controllerDecide temperature controller (Mid February)(Mid February)

Order heater and thermocouple prototypes.Order heater and thermocouple prototypes. (February)(February)

Test these protypesTest these protypes (March-April)(March-April)

Criteria For Heater SuccessCriteria For Heater Success

Heater heats solution to specific Heater heats solution to specific temperature temperature

Heater stays securely on IV bagHeater stays securely on IV bag Completed device is easy to mount Completed device is easy to mount

onto bagonto bag Heater is portable, small, and flexibleHeater is portable, small, and flexible

Sample CalculationsSample Calculations Warm up Power:Warm up Power:

P(watts)=mCp(tf-Ti) / tP(watts)=mCp(tf-Ti) / t 1000(g)*4.19(J*g/C)*(40 C-25 C) / (600s)= 104.751000(g)*4.19(J*g/C)*(40 C-25 C) / (600s)= 104.75 125.7 W with heat loss125.7 W with heat loss

Conduction Loss:Conduction Loss: Pcd=KA(Tf-Ta) / 3.412*LPcd=KA(Tf-Ta) / 3.412*L

4.08 Btu*in/ft^2/F/hr*(12.9 ft^2)*(104F -77F) / 3.412*15.24 4.08 Btu*in/ft^2/F/hr*(12.9 ft^2)*(104F -77F) / 3.412*15.24 in=27.33Win=27.33W

Radiation Loss:Radiation Loss: Pr= E*A(0.173x10^(-8))*(Tfr^2-Tar^4) / 3.412Pr= E*A(0.173x10^(-8))*(Tfr^2-Tar^4) / 3.412

0.98(.1713*10^(-8))*((104+460)^4-(77+460)^4) / 3.412 = 8.87 W0.98(.1713*10^(-8))*((104+460)^4-(77+460)^4) / 3.412 = 8.87 W