# Biomedical Engineering: power (W) needed to warm blood

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1. Sep 12, 2016

### A Furious Potato

1. The problem statement, all variables and given/known data
Fast-flow blood warmers (pictured below) can be used to heat blood products (carefully and uniformly) when rapid, high-volume transfusions are necessary, in order to prevent hypothermia in the patient. The blood product density and specific heat can be assumed to be 1.12 g/cm3 and 3.8 kJ/kgK, respectively. If the blood product initially is at 8 degrees Celcius, the target temperature is 37 degrees Celcius, and the maximum transfusion rate is 900 ml/h, what is the theoretical heating power (W) needed for this machine?

2. Relevant equations
q=mcΔT
W=J/s
Density=m/V

3. The attempt at a solution
Sorry, this is a new type of problem that our prof. gave, and he also gave no hint/formula so I am lost. Where do you implement the transfusion rate in the calculation? Do I treat it as the volume?

Last edited: Sep 13, 2016
2. Sep 13, 2016

### billy_joule

Use your first equation to find energy to heat the 900ml.
Use the second equation to find the power required to do it in one hour.
Or combine the equations to do it all in one step.

3. Sep 13, 2016

### A Furious Potato

Thank you :)

4. Sep 21, 2017

### Hamza313

please tell me how you figured this out because I actually have like the exact question on my homework, thank you.