TEMPERATURE IN TISSUE DURING LASER IRRADIATION

As tissue is being irradiated with the laser, some of the laser is absorbed, producing heat within the tissue.  The temperature (T) in the tissue as a function of time (t) as it is being irradiated can be given by the following equation:

T(t) = T₁(1-e^-t/τ) + T₀

where T1 = asymptotic temperature in oC, τ = time constant in seconds, and T_o = body temperature (37^oC).  After irradiation, the temperature in the tissue begins to cool.  This cooling can be described by the following equation:

T(t) = T₂(1-e^-t/τ) + T₀

where T₂ = (T @ end of irradiation - T_o) and t = (time – time @ end of irradiation).

For this homework, you will do the following:

PART 1:

You will create two graphs. Each graph will be put in the same figure window but tiled next to each other. The graphs will contain the following:

Graph 1:  The first graph will be the temperature during laser irradiation as a function of time find outd using equation 1 for time = 0 to 600 seconds.  The temperature was measured in a sampling frequency is 1 s.  Use equation 1 to find out the temperature as a function of time and using the following constants:

T₁ = 100^oC
τ = 300 s
To = 37^oC (body temperature)

The graph should have the following:

title = “Temperature in Tissue During Heating”
x-axis label = “Time (seconds)”
y-axis label = “Temperature (Celsius)”
Plot type:  Scatter plot (not a line plot) with black points (dots)
y-axis = 0 to 140
x-axis = 0 to 800

Graph 2: The second graph will be the temperature after laser irradiation (cool-down) as a function of time find outd using equation 2 for time = 600 to 1200 seconds.  The temperature was also measured in a sampling frequency is 1 s.  Use equation 2 to find out the temperature as a function of time.

The graph should have the following:

title = “Temperature in Tissue During Cool-Down”
x-axis label = “Time (seconds)”
y-axis label = “Temperature (Celsius)”
Plot type:  Scatter plot (not a line plot) with blue diamonds
y-axis = 0 to 140
x-axis = 600 to 1400

PART 2:

In the second part of the program, which is after the program has plotted the graphs, the program is going to request the following “input” from the user:

“At what time would you like the temperature for?”

Once the user has input the time in which he would like to temperature for, the program will respond:

“The temperature at time ??? (the input) seconds is ??? (the output temperature) Celsius”.

where the output will be in a format that will have 3 digits to the right and 1 digit to the left of the decimal point.

After this the program will say:
“Have a nice day”