I just did a bit of research and found something interesting about what you can't patent.
Abstract Ideas
Abstract ideas are concepts like pure mathematics and algorithms. You cannot patent a formula. However, you can patent an application of that formula. Thus, while you cannot patent a mathematical formula that produces nonrepeating patterns, you can patent paper products that use that formula to prevent rolls of paper from sticking together.
Can I Patent Software?
Although software functions by using algorithms and mathematics, it may be patentable if it produces some concrete and useful result. However, what cannot be patented is software whose only purpose is to perform mathematical operations. Thus, software that converts one set of numbers to another will not be patentable; but software that converts one set of numbers to another to make rubber will be patentable.
What Cannot Be Patented | LegalMatch Law Library
This appears to mean you can't patent variable wattage. Variable wattage is achieved by a mathematical formula. So what is it that Evolv holds a patent on? It must be an invention that turns the mathematics into a device that performs a function of the formula.
But someone stated the patent wasn't on a device? And it seems to me what they did falls into "software whose only purpose is to perform mathematical operations"?
*edit*
Gist of the patent, a "power manager" specifically for vaping comprised of widely available components and control software and or hardware.
The power manager 230 can measure or collect measurements of two of the following: a heating element resistance, an output voltage to the heating element 220, and an output current of the heating element. From these, an actual power output of the heating element 220 can be calculated or measured by use of Ohm's law (e.g., Voltage=Current*Resistance, or a variation thereof) and a definition of power output (e.g., Power=Voltage*Current, or a variation thereof). The power manager 230 can directly control power to produce a regulated and uniform output from the vaporization of the material from the heating element. In an embodiment, a control loop can be used (e.g., feedback, feedforward, among others) to dynamically control the power output to the heating element 220.
In an embodiment, a direct power regulator can be utilized in which the direct power regulator uses a microcontroller to measure a system property or parameter, perform control in software, and then output a control signal to a standard DC-DC structure, such as a regulator (e.g., boost regulator, among others). It is to be appreciated that any suitable combination of hardware, software, or circuitry can be implemented with the subject innovation and the disclosed examples are not to be limiting.