Weeks 8 & 9: Prototype Innovation and Construction

These two weeks have been mainly focused on actually creating a physical prototype of the design we've developed. The ProE model of the lock mechanism provided a guideline to building the prototype.  As prototyping was being done, problems began to arise with the actual design. Specifically, the two magnetic arms that would clamp to the door were removed from device.  The reason for removing the arms was because they were simply unnecessary, and a simpler solution was found.  After removing the arms, the magnets were relocated to the circular part of the outer casing.

Normally, the model would include metal casings for the keyhole and the magnets that would attach to the doorknob. The rotator switch at the end of the rod would also be metallic. However, due to limited resources, we decided to create a non-functional prototype of the design made of household materials such as cardboard, paper, and plastic. Therefore, we could still conveniently achieve the physical design of the model.

We plan to use this prototype as a presentation aid for the final project presentation we will be giving next week. Thus, our ideas can be easily expressed in the form of a tangible object. The presentation will be enhanced by including a demonstration of how the mechanism would be helpful to subjects' with the inability to naturally open a lock on a door.

Bringing our project to a conclusion, we have learned that an initial design might seem perfect at first, but after prototyping, obstacles begin to rise. Consequently, the design must be refined in order to meet the specifications of the design changes.

Week 7- New Design Prototype

This week, we attempted to obtain materials from Home Depot for the new gripper prototype . However, we were unable to acquire the correct materials we needed. For one, the PVC piping that we intended to use as rods for the outer casing as well as the key-holding compartment was too large at Home Depot. In order to build the prototype, we will need to discuss other materials we could possibly use. In addition, we decided it would benefit us to have a ProE design of our prototype, so that we are able to model our design. Hopefully, that will make it easier for us to acquire the proper materials to build our prototype. Once we decided to make a ProE design of our prototype, we realized that every group member had a different idea of what the prototype will look like. This week, we focused on combining our ideas into one, and coming up with one model to use to build our prototype for next week. We also discussed other materials to use for our prototype that would be easy obtain and modify in order to assemble our final prototype smoothly. In addition, we considered utilizing the 3-D printer available in the engineering lab to print out our ProE design with plastic materials. Our tentative model of the casing is shown below:

Week 6 - Material Search

We began searching for material to build the prototype. We have found a tool that we could possibly use at a CVS retail store. However, we are currently debating whether the material from the CVS brand will be sturdy enough to build a proficient prototype. We are currently searching for a better material for the same object at a price that is not too expensive. We plan to find the material prior to the weekend and begin building the prototype during the weekend. 
Magnets will be bought from our friendly neighborhood Home Depot. We plan on buying gorilla glue or wood glue in order to keep the magnets on the door. We are also currently trying to find some way to test the prototype in an accurate manner. We plan to ask a friend that smokes cigarettes to quick for a day, giving them a slight tremor. However we hope to find a better tester such as a real Parkinson’s patient to test the prototype.

Week 5 - Change in Overall Design

After taking the time to look at our initial design for our problem, we noticed that building a prototype for the exoskeleton would be too difficult and too time consuming. Plus the ease of use would be too difficult for the patient trying to operate the device. After deciding to find an alternative way to approach the problem, we came up with another design, that is much simpler to builder and is more accessible for the patient, and it still allows the problem to be solved. The new design is based off of the design for an extending grabber, which is a mechanism that is used to grab items that may be out of reach, such as wires, balloons, tools, boxes, etc., with much more ease. See the figure below.

Figure 1: Picture of an extend grabber [10]

For our design, we will be eliminating the whole extended grabber mechanism, except for the head, which will basically be used as the whole mechanism for our project.The basic design for our new approach is that, two magnets will be placed on a door; one above the key hole, and one below. According to your height or ease of use, you can place the two magnets at any distance apart (with in reason). Likely, another two magnets will be attached to the prong like extenders of the head. These will attach to the magnets already on the door, allowing the mechanism to be stable while being used. Next, in the middle of the device, there will be a large round casing that will house the key for the lock. The key will be attached to a smaller casing that is free to rotate, using a dial like device on the back of the head, at the end of the second casing, so you're able to turn the key, to unlock the door. The smaller casing will be retractable so that once the key is taken out of the hole, the key goes back into the mechanism, inside the casing. See the figure below for a better understanding of how the device will look.

Figure 2: Proposed new design

Week 4 - Change in Initial Design

Throughout the past week, it was decided that our group was being too ambitious in our design proposal. Therefore, from now on we will be focusing on a more specific design to perform specific jobs. In other words, as of now, our goal was to assist people with hand tremors perform daily tasks. However, there are many problems with trying to do so because there are many factors that need to be overcome. For example, our gripper initially wasn't designed to relieve tremors that begin in the upper arm- we were solely focusing on the forearm. If someone was trying to use our gripper to reach something from a cabinet in their kitchen, they would still be unable to hold their arm steady because although their forearm may be more controllable, their forearm is still shaking. Because of the complications with trying to help individuals with hand tremors perform all daily activities, our group will focus on assisting these individuals with only one type of activity. We will be focusing on creating a gripper that will help individuals use a key to open a lock and turn a doorknob in order to open a door.
In addition, materials have not been obtained in order to build the initial prototype. While waiting for materials to come in, a simpler 3D model was constructed out of paper. This is simply a model with no functions and does not have any abilities to perform tasks that the initial prototype will be designed to perform. Figure 1 shows the gripper from the front, with the fingertips in view. This is where magnets will be attached.

Figure 1: Frontal view of glove

Figure 2 shows how the gripper fits onto a persons hand. It is not possible to have a universal glove that will fit everyone. Since most people have hands of different sizes, gloves need to be custom designed to fit one's hand. This is a constraint in our design. In the figure below, the glove was made to fit the hand of one of our group members.

Figure 2: View of how the glove is worn

Week 3- Initial Design and Materials

After refining our solutions, we have come up with an initial design for the exoskeletal gripper. The diagram below shows the initial design, but only for two fingers. The actual prototype will cover a full hand; the diagram below only shows the beginning of our design. 

Figure 1: Initial sketch of the exoskeletal gripper

The materials necessary to build a prototype of this design were also refined. A tentative list of materials includes: a soldering kit, rings to use as hinges, copper wire, and magnets. For this project, an actual design will not be made. Only a prototype model that does not have the full functions of our project will be constructed. Figure 2 shows a basic soldering kit which seems sufficient for our group to build our initial prototype. The brass rings to use as hinges, spool of copper wire and magnets are shown in Figures 3 to 5 respectively. The hyperlinks for the purchasing sites for the following materials are located in the project overview section under materials within the subsector named projected budget.

Figure 2: Soldering Kit [4]

Figure 3: Brass Rings [5]

Figure 4: Copper Wire Spool [6]

Figure 5: Roll of Magnets [7]

Material Procurement will be completed by the end of next week. The pictures of materials posted are not the exact materials that will be used in the project.

Week 2- Constructing Project Proposal

Since our group is aiming to assist individuals with hand tremors, we thought we would look into real people experiencing hand tremors in order to design our product accordingly. From these videos, we decided to focus on minimizing shaking due to hand tremors, and assist individuals to grasp objects and perform daily activities more efficiently.

http://www.youtube.com/watch?v=fEM9OiWveS4&feature=related

The man notes it is very difficult to grip objects. For example he has trouble keeping a cup of coffee steady to drink from or to hold a bolt in order to srew into a solid object. The video is used along with other videos to gain background knowledge of the tremor from primary sources and experts.

http://www.youtube.com/watch?v=E26GsUSjvdw

Similar to the man in the video above, this woman also has difficulty grasping object due to hand tremors.

After viewing the videos, we discussed possible solutions and decided to focus our efforts into creating an exoskeletal gripper that individuals would be able to wear in order to relieve hand tremors. Refining must be done on these solutions in order to fit design constraints and follow deliverables.

Week 1- Deciding Freshman Design Project

The choice of topics ranged from fabricating electrospun chitosan polymer membranes for filtration applications to remote operated submersible for water quality testing and finally to human assist-devices for disabilities or rehabilitation. Our group chose to pick the topic of human assist devices with the concentration on developing a product to help control hand tremors. The range of all of our majors brings a lot to the table, allowing us to think up designs for the project with someone majoring in biomedical engineering, a related field on developing replicated body parts, mechanical engineering to help put the assembly together for the prototype, all the way to computer engineering, to help sketch and produce a three dimensional model of the design using Pro-Engineer WildFire. Our initial goal for this project is to research upon this topic of hand tremors and develop a basic solution, to help resolve this issue. Once that is completed, we will go on to building a prototype and testing it and modifying its design, allowing the solution to be as much user friendly as possible.