Jun 18

Pressurometer: Pressure Sensitivity Through Tagged Objects

This is another idea I have had over the last month working on Multi-Touch Environment under Andrew Kun, on Microsoft Surface. One of the key features lacking on the multi-touch surfaces is the ability to measure the pressure levels exerted by the user, which can be effectively used to gauze certain parameters that the user wants. For example in a scrolling widget a pressure sensor can convert the pressure into different rate levels of scroll bar movement, or a zoom application could use the pressure values to determine the rate of zoom in or zoom out.

The idea is inspired from the this video, click here to view.

The design is simple. The interface is something that converts the physical stress that the user applies to measurable displacement value. Here is a flowchart explaining what I wish to do

Figure 1

I have not still figured out what the object could be, it should do something like the following

Figure 2

We use two tagged objects for measuring the relative separation between them as a measure of the pressure applied by the user. We could also use more tagged objects to get a better sense of the direction of using pressure. The sense of direction mapping to pressure could be as follows:

Figure 4

The design above could be used as a pressure sensitive joystick kind of a device for 2-D motion games.
The image above shows the semantics that can be associated with the  each of the four tagged objects as follows:

1) The four tagged objects  N,S,W, E can be detected for motion based on their relative displacement. If one of the four is significantly displaced than the others, it would mean a one directional motion.

2) Otherwise a combination motion could be if two are comparable, and directions such as NE, SE, SW, NW (5,6,7,8 respectively) are got.

3) A combination of three would be suggestive of multi-touch (more than a single finger).

4) A significant displacement in all the four means a downward motion of hand (could be like an accelerator), with the release being a reduction resulting in pressure which in turn means the distances decrease between the adjacent tagged objects.

This is just an idea though and getting a an apt elastic-object is currently the major issue for implementation on the Microsoft Surface.

Ravi Tandon,
Intern, UNH.