detecting removal of USB flash drive

[horace1]

I have an application where I am using a PIC24 to switch a USB flash drive between the PIC USB input and a PC. The switching works without problems.
However, when the USB flash drive is switched thru to the PC I need to detect if the flash drive is removed.
I thought of looking at the power line to the flash drive. Initial thoughts were to use a current sensor such as the LTC6101
Linear Technology - LTC6101 - High Voltage, High-Side Current Sense Amplifier in SOT-23

any ideas for a simpler solution? I don't need an accurate measure of current, all I need to detect if the flash drive is drawing power or not

 

[RAJAT AGGARWAAL]

1. Connect a led with diode
2. Or connect a spare pin with diode on power line of usb with a diode on for mcu power if you are using in that way(i once make 18f2550 with vb , my board has li ion battery and i want to make it good so i attach a buzzer with a spare pin when get connected or disconnected and then to write data in i2c eeprom when gets disconnected)that was a nice thing ,now my friend is using that some 2 years
3. I like to say current sensing second component is not for nice embedded project

 

[horace1]

Thanks for idea - will give it some thought !
what we need to do is sense the removal of the USB drive by the program so it is not user control
the current sense would work OK but, although a single device is cheap, it becomes expensive when we may be making thousands of the units