What effect does an increase in tissue resistance have on heating during diathermy?

What effect does an increase in tissue resistance have on heating during diathermy?

• A. Increase in heating
• B. Decrease in heating
• C. No change in heating
• D. Variable heating depending on tissue type

Answer: (A)

Heat in diathermy comes from the tissue’s electrical resistance converting energy into heat. The power turning into heat is P = I^2R, so with the device delivering energy at a given current, increasing tissue resistance will produce more heat. In practice, tissues with higher impedance tend to heat more under diathermy, which is why impedance is an important factor to consider. While device settings can influence how energy is delivered, the direct effect of higher resistance is more heating.

Heat in diathermy comes from the tissue’s electrical resistance converting energy into heat. The power turning into heat is P = I^2R, so with the device delivering energy at a given current, increasing tissue resistance will produce more heat. In practice, tissues with higher impedance tend to heat more under diathermy, which is why impedance is an important factor to consider. While device settings can influence how energy is delivered, the direct effect of higher resistance is more heating.