Monitor Weight Changes with Pressure Sensor

Objective: Utilizing a pressure sensor e.g. Flexiforce, monitor weight changes and send data wirelessly to a base unit for real-time analysis. Weight can vary from 0lbs to 300lbs. In most instances the sensor will be engaged sporadically throughout a given day. Battery life is an important consideration. Communication between the sensor and a base unit (i define a base unit as a PC that has programs that parse out information regarding changes in weight and takes appropriate action based a pre-defined algorhythm) is the other important consideration. I’ve looked at possibly incorporating an Arduino board in the solution but I’m not sure that it’s necessary. I’ve read several articles and some books regarding wireless sensor networks so I have a very rudimentary idea of how this might work. I realize I may not be providing all the information necessary for anyone to begin to make a recommendation so I’m hoping any questions with follow-up answers will get me to a possible solution. I sincerely appreciate anyone’s advice that will get me moving in the right direction.

Weight can vary from 0lbs to 300lbs.

That's a pretty large range. What is causing the changing weight? Certainly not dieting.

How often does the weight change? By how much at a time? How important is it that the actual weight be monitored (as opposed to, for instance, checking every 5 minutes)?

Well start by researching 'load cells' that cover the weight range you need to cover. Then you will need good instrument quality input circuitry to amplify the low level load cell voltage range (typically like 0 to 10 millivolt) to a voltage range suitable for an arduino analog input pin. Load cells are precision sensors that are designed for weighing loads accurately and used extensively in industry.