Free Body Diagrams and Final Pillow Model


These free body diagrams show the amount of gravitational pressure felt by an individual depending on their inclination with respect to the ground (zero degrees).

As is seen, when there is no inclination, the force of gravity on a person is the greatest. If the person is at a 60 degree incline however, the force of gravity is only equal to mgcos(60). This means that as the inclination angle increases, the force of gravity exerted on an individual decreases. This also means that it becomes easier for a person to take in more oxygen as his/her air passages are less-blocked than they were if s/he were to lay down flat.

The following images are the final models of the elevated pillow mechanism. The first image has an elevation angle of 45 degrees while the second has an elevation angle of 60 degrees.

Forty Five degree angle

Sixty Degree Angle

Cutting PVC pipes at the Machine Shop!

PVC pipes needed to be cut to a measured length in order to be placed underneath the wedge pillow to create a base. At the machine shop, the pipes were cut using a band saw and then "cleaned" using a sander.

Final Pillow Base


These are pictures of the pillow's base and essentially the mechanism with which to elevate it. The ply wood attached to the sides of the PVC piping have 2 'rungs'. Screws can then set themselves into these rungs, raising the top half of the base to the desired height. There are only two heights with which to raise the base as the length of the ply wood acted as a limitation.

Seventh Meeting

    The group has completed the construction of the top half of the pillow. In the following weeks, the group will have to come up with materials that could be used if the pillow was to be made in real life. Materials that have been used in the model include foam of the wedge pillow, extra firm pillow stuffing, and PVC piping. Materials that are being considered for the pillow if it were to be constucted in real life include the foam of the wedge pillow, tempur pedic memory foam, and titanium.  
    Free body diagrams will be drawn as well to help group members understand the effects of atmospheric pressure on a person when s/he is laying down or sitting upright. Additionally, a pulsoximemeter will be used to collect data concerning oxygen levels at different positions (ex. laying down, 45 degrees, sitting upright). All this data (even though they will be estimations) will help determine the best angle to position a person with COPD  so that they can take in the most oxygen.

Fifth Meeting

The group completed the Pro/ENGINEER model of the intended pillow. The group also developed a design for an elevating system that is composed of PVC piping. This system would consist of a bottom frame and a top frame as well as an intermediate piece that is attached to the top frame and hooks into the bottom frame, changing the height of the pillow. The group intends to have materials to build this system within two weeks. Materials would include PVC elbows, T's, and piping, and screws (to create a pivot point for the intermediate piece and top frame).

Figure 1. PRO/Engineer Model of Pillow.

Figure 2. Rough Sketches of pillow and base structure

Figure3. Side and top views of pillow (base not included). 

Final Diagram of Base:

Fourth Meeting

Materials for the construction of the pillow (following the idea the group came up with last week) have been purchased. The two pillow were purchased from Target while the wege pillow along with the neck support pillow were bought from BedBath&Beyond. This is different from what was planned (and written in our proposal in Week 3) as our purchases were to be made from WalMart.

While the bottom of the wedge pillow would have a beach chair mechanism attached to it, the top of the pillow would have ridges. These ridges would be made of pantyhose material stuffed with regular pillow stuffing. The ridges would then either be sewed onto the top of the wedge or laid down with wire. There will also be a small curvature toward the top half of the pillow to cradle the head and neck.

Third Meeting (April 19, 2012)

This week, the group conducted two interviews with constituents suffering from COPD (these interviews can be found in the previous posts). 

Further changed our orgiinal design. The newly proposed ideas included using a wedge as a building block and devising a mechanism to elevate the pillow when necessary. After consulting with Dr. Allen, the group considered including a pulse oximeter with the design. This would be used if a patient woke up in the middle of the night. The patient could then test their oxygen levels to determine whether the pillow needs to be adjusted.

As of this week, many ideas were proposed. The group's initial idea was to have a motor raise the pillow which later changed to having a conveyor belt mechanism with an attached ball that would move up and down, raising or lowering the pillow as necessary. Another idea was to have the patient manually stuff the pillow to raise or lower the height of it. These ideas were discounted because they would have had to be implemented inside the pillow and would thus be uncomfortable. Additionally, the motor could be a potential source of noise during the night, and manually stuffing the pillow would be labor intensive.

The group decided on one final idea. A wedge pillow would be used as a building block. The base of the wedge pillow would have a beach-chair mechanism attached to it. This would allow the patient to raise or lower the pillow if necessary.

 



Figure 1: The above image displaces an open and a closed airway.
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Figure 2: The above figure shows an open airway.
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