Table A.1.

General performance of heating systems

		Thermal effective penetration depth	Dealing with problems at the interfacesa	Spatial power control		Thermal effective field size	Ease of use and positioning	Comfort to the patient	Temperature control	Commercial
				Dimensions	Resolution
EM waveguide	Single applicator	+	++	1D	–	- to +	0	0	+	yes
	Array	+	++	2D	++	0 to ++	-	0	++	no
EM microstrip	Single applicator	0	++	1D	–	0	+	+	+	yes
	Array	+	++	2D	++	++	+ to ++	+	++	yes
EM capacitive		+	–	1D	–	+	++	+	–	yes
US	Single applicator	++	0	1D	–	-	0	+	+	no
	Array	++	0	3D	++	-	+	+	++	no
IR		–	++	2D	+	++	++	++	+	yes

The performance is indicated by following grades: ++ very good, + good, o fair, - poor, – very poor

^aDealing with the problems at the interfaces (fat layer under the skin and/or muscle/bone interface)