In this fourth round of prototyping we wanted to answer the following questions:

• Should our goal product be a functional or looks like prototype?
• How can we improve the handles to make them sturdier and fit in the seat while rotating?
• How can we create more room between the handles without increasing the overall width of the device?
• What improvement can be made to the locking mechanism to make it more durable?

In order to answer these questions we first took to Solidworks to deep dive and fully design our prototype. We changed the locking bracket so it would be thicker and have two mounting points on top of the seat rather than on the side. Additionally, we changed the handles so the plunger would be moved to the back to allow for more room for the user and avoid hitting the seat itself. The seat size was slightly increased and things including adding fillets to the base for support, cushions, color, and nuts/bolts were added.  This full Solidworks model can be seen in the pictures and video below.

The team then used this CAD model to physically build the model. Changes made in the physical model compared to the Soldiworks model included slotting out the the square holed bar. Pictures of this model can be seen below.

Moving forward the team would like to address:

• Continue to investigate options that would allow for more space between handles for persons with wider hips.
• Add slider block inside handle to increase handle stability when adjusting height.
• Work on design of “plunger” caps to increase gripability.
• Look into better material for cushion.
• Manufacture locking mechanism out of metal
• Look into new designs and manufacturing methods for plunger pins.
  • 3D printing or Machined pieces
  • Improve actuation by removing threaded section that passes through handle.
• Try to get back to older adult living facility for more user testing (with covid hopefully going down 🙂 )

For this third round of prototyping our team wanted to focus on making a more ergonomic and fully functional design. In this prototype the team wanted to focus on:

• Making the seat more ergonomic and softer
• Improve handle design, to be stronger and more appealing to the eye
• Ensure the bearing/platform of the seat can support more weight
• Improve the foam on the bottom of the seat so taller people can also use the seat
• Find a way to move the handles/seat more adjustable
• Make a more user appealing prototype

The team took this considerations into place and met with Ohio State’s Kevin Wolf to get additional design opinions and input. Ideas such as using a compressor/air, using one handle, using one locking mechanism, and materials were all discussed. After this design discussion the team began redesigning the handle bars and locking mechanism. For this prototype, the handle bars were redesigned to add adjustability vertically. Initially, the team thought about horizontal adjustment, but realized that in a car space this was not a possibility given room in a seat. To improve the horizontal dimensions of the seat to allow for a more user friendly device for all people, the team moved the handles so they were out wider on the base on flanges. Additionally, to improve space, the locking mechanism was moved to the side of the seat base so it would not affect user movement or space. As a result of this locking mechanism movement, the base also had to be redesigned to accommodate such locking and was configured out of layers. Finally, to improve ergonomics, the under base cushion was changed from solid foam to a shredded foam and a seat cover was also to be added for comfort.

The team first modelled the idea in Solidworks intending to use both stock parts and 3D printed parts. Images of the Solidworks rendering are shown below. Note that these drawings to not include the seat cushions.

The prototype was then assembled by the team. Pictures of this assembled product are shown below.

This prototype was then tested with three people in three different cars. Pictures of these tests are shown below. Here are the results of these tests:

• all three people fit in the seat, but one person did express it would have been nice to have more room
• the seat rotated well, but the handles hit the back of the seat, stopping full rotation
• seat was too tall for shorter cars, causing people’s heads to be at the ceiling

This prototype was presented to a stakeholders including an occupational therapist with the main feedback being:

• ensuring that the base is big enough to support all individuals even those whose hip width might exceed the seat cushion
• wondering if the armrests could be height adjustable while still maintaining their sturdiness. To address these concerns, in future iterations, the team

To address these concerns, in future iterations the team wanted to make sure that the whole arm rest could be detachable to allow for easy removal from the seat base in the case that more room is needed and increase the seat base to its maximum value by moving the handle plungers to the back. Lastly, the team wanted to add more support to the plungers used within the handle, to add extra strength to the design.

After receiving feedback on the prototype from the class, in this prototype round we wanted to focus on how to attach our seat to the base securely and how to lock the seat from rotating. The questions we wanted to answer were:

• How do we want to lock and unlock the seat when rotating?
• What is the best way to adjust for angles and unlevelness of car seats?
• How can we attach the device to the car seat?
• What mechanism can we use in the handles so they can move efficiently and are easy to use?

The team brainstormed ways to lock the seat in place with the handles. Below are the initial design ideas. The idea the team decided to pursue involved putting holes into the base for a pole to fall into, thus locking the seat rotation. This pole would be a part of the handle design. One part of the handle would involve the pole, two stoppers, and a spring in between. One of the stoppers would be encapsulated in the base of the handle with the other exposed to pull up on and the spring to help guide the pole into a hole. As the user rotates they hold up on the lower stop and release to lock it.

For the attachment to the seat, the team wanted to use a buckle and straps. To connect it to the seat, the team had the idea to add slits to the base of the seat platform through which the strap could feed. It could then be buckled around the seat.

The team took these ideas and mocked up the whole prototype in solidworks. Images of these mockups can be seen below and feature the whole handle mocked up with a rod, ceiling flange pieces as the stoppers, a spring, handle encasings to be 3D printed and the base with holes. On the base these slits can also be seen.

The team aimed to 3D print the handle encasing and to laser cut the base and seat. Every other part was to be purchased from stores. Additionally, thick foam was bought to be added to the base of the seat to allow for more molding to the seat bucket.

Unfortunately the 3D printer could not finish in time, so the handles had to be made out of wood for this round. The same mechanism was able to be constructed. The final prototype is shown in a car below.

From sitting and trying out the seat, the team realized the foam purchased may be too thick for fitting in the base and not adding too much additional height. Additionally, the team realized that the seat and handle dimensions are small and not adequate for a variety of people, therefore more adjustability needs to be added to the design. Finally, when testing the rot0tating structure under human weight, the team realized they may need to add spacers or extra support so the top seat does not fall too close to the base, making it hard to turn/lock.

From the class, the team received the following feedback:

• Consider when you sit the way that the base and swivel seat touch, look at putting spacers in
• Potentially use a bean bag  instead of thick foam for under the seat
• Look at amperometric data for what width a seat should be
• Look into using one handle that is detachable/moveable depending on the side you are on

The first step of our prototyping journey back from winter break was choosing what design we wanted to focus on. After talking among ourselves and discussing with our stakeholders we decided to go with the rotating seat with a locking mechanism. We came up with some questions that we wanted to answer with the first round of prototyping.

• What is a viable way to attach the swivel seat to the base?

• What shape can be used to ensure clearance with the seat (is a circle the best choice)?

• What shape should the base be to position the swivel seat further forward in the seat?

• Ways to possibly lock/unlock the seat so it doesn’t swivel when you don’t want it to?

• How can we have a way to push up the seat when getting out of the seat? (secondary as we could have the seat lock and the handles server this purpose)

• Do we need to limit the amount of rotation of the seat?

• Best shape for handles as well as the material of them to support weight the best?

We mainly focused on the first four questions and brainstormed how we wanted to attach the cushion to the base. We started sketching ideas of designs for the shape.

We then narrowed down our ideas and decided on the design below for our first prototype. We wanted a circular cushion on top to make sure there is enough room for the person’s rear end but also wanted a base with a flat back to go against the seat.

We then started on assembling our prototype. We ordered a bearing to allow the top piece to rotate. We planned on using wood for both parts of our first prototype, but unfortunately the wood we provided was too thick to laser cut, so we had to use cardboard. The prototype for our first round is below. Here is the in class presentation we gave: Prototype Round 1 Presentation

To get a better idea of this prototype we put it in a car and were able to see its fit and where there were some problem areas. Pictures of the prototype in a vehicle can be seen below. As can be seen, when it sits on the seat there is a bit of space underneath the platform. The team hopes to fix this problem in future iterations by maybe adding foam as is displayed in the last image. It can also be seen in the second to last image, as pressure is placed on the seat, the whole thing bows and separates slightly. Stronger materials will be necessary to prevent bowing under the weight of a person.

After presenting to our class this is the feedback/advice we received:

• look at something like memory foam to put under flat base so it can mold to the seat bucket
• look at how baby car seat are attached
• think of ways to attach prototype to seat, maybe attach onto seat or around
• maybe go up and lock prototype in place via the entire back of the seat
• look into having handles that slide in/out and adjust
• release of handles? should this be a safety concern?
• car seat regulations?
• potentially have a button you hold when you want to spin and release when you want to lock

This prototype idea looks at making a more easily collapsible walker. The solution aims to make it so that older adults can use their walker to enter a vehicle and easily store it near where they are sitting for easy use when they exit. It will mitigate the need to store a walker in a back seat or trunk which requires retrieval after exiting. In this prototype design the inspiration was a foldable baby stroller which has many joints that bend and allow them to fold up. To prototype this hinged joints on the legs were modeled so that the walker could fold up relatively small. The team is still exploring other ways to make a walker foldable such as with telescoping legs maybe.

Questions:

1. How to make the design fold small (hinges, telescoping, folding, etc.)?
2. Does the design fold up relatively small? How small?
3. What ways can the prototype work with the limited dexterity of older adults?
4. How can the walker be kept sturdy when in use but also collapsible when not in use?
5. Can walker be collapsed while in a seated position of a car?

This prototype was an example of an extendable seat platform to allow the user to have more room to sit down. This product would be stored by attaching it on the side of the seat in a vertical orientation. When in use, the user would fold the product down to a horizontal position, which would extend the two bars or supports to their full length. Then user would pull out the platform, which is made smaller plank pieces that can be used to sit on. When the user is done using the product, they can pull the platform back in, then flip the product back into the vertical orientation to collapse the supports.

Questions:

1. How much space would be needed in order to have a similar product attached to a seat?
2. How could the design be condensed into a smaller state?
3. How much of a platform would be need in order to be beneficial?
4. Is there an alternative way to create the same function of storing and putting out a platform?
5. Would handles or a seatback be necessary for such a product to make the product safer/more ergonomic for use?

This prototype is a design for a rotating seat. There is a piece of cardboard that represents the stationary piece that will stay put on the seat. On top is a rotating piece of Styrofoam that represents a cushion that the person will sit on. This will help them sit in the car and rotate to face forward so they don’t have to twist by themselves. There is a handle on each side that allows the person to hold for balance and push on for leverage as they exit the car.

Questions

1. How can we lock the cushion so the device stays in place while person is driving?
2. Will the handles get in the way when the person is driving?
3. How do we make the handle heights adjustable to account for people’s heights?
4. What is the best way to connect the cushion to the stationary part?
5. How high should the cushion be?

Seat Belt Prototype:

The seat belt prototype is a product designed to help older adults put on their seatbelts. The problem experienced by older adults is that they cannot rotate their body to grab the seat belt. This product solves that problem by utilizing an arm that extends from the left side (if in the driver seat) and grabs the seat belt, pushing the seat belt strap forward so that it is more parallel with the older person’s body. This allows the older person to reach the seat belt strap without having to rotate.

Questions answered from the prototype:

• Can the seat belt strap be reached without having to rotate your body?
  • Yes, the seat belt strap is able to be reached without rotating the body. The arm must be able to extend enough to put the strap about parallel to ones body while sitting down. The actual mechanism/mechanical design of the arm extending was not discussed during this rough sketch prototype.
• Is this idea compatible with a vehicle (does the prototype fit/can it be attached somewhere in the car)?
  • Although this prototype was not brought into a car, and the mechanical design was not discussed, the prototype seemed compact enough to fit in a car. Pictures of vehicle interiors were examined and interior dimensions were studied. The prototype and prototype arm was able to fit in all interiors.
• Is there an obvious way that this product can fail?
  • After the prototype way made, the group immediately realized that an obvious failure point of this product would be that the arm that pushes the seat belt forward, might “miss” the belt strap and fail to bring the strap forward. This was a failure that the group was able to realize only after making the prototype. This issue was solved by making a hook on the end of the pushing arm so that the belt strap has no way of slipping out.
• Is there a better way/design to achieve the function of this product?
  • The idea of a rail system was discussed to the class, but it was brought up that this idea was implemented in vehicles before and failed. The rail system also adds more complexity and makes the process of getting in harder, which is not ideal for our users.
• What methods of manufacturing might be used for this product?
  • From the prototype, it was found that only a relatively small force is needed to push the seat belt strap forward. This means that the hook, and maybe the arm could be made of plastic from additive manufacturing. If a smaller size is needed, aluminum could be used for the arm, which could be turned on a lathe.