Golf Prosthesis Final Design Report (P1)
Sponsor Background and Needs
Missing Links consists of fourth and fifth year Cal Poly students working on a senior project with QL+ (Quality of Life Plus), an organization dedicated to improving the lives of wounded veterans injured while serving our country in Iraq and Afghanistan. These individuals are also known as wounded warriors. The project is specifically dedicated to help bilateral amputees swing a golf club and make consistent contact with a golf ball. The goal of this project is to design a golf prosthesis to help these individuals experience the game of golf they enjoyed before they were injured. The stakeholders for this project include the sponsor QL+, wounded warriors (specifically bilateral amputees, as the primary customers for our product), prosthetists who can implement our attachment for further applications, and the team of engineers developing a solution.
To construct a device allowing a bilateral amputee to swing a golf club consistently and effectively. Our primary goal is to create a device that allows a bilateral amputee to use their everyday prosthetic arms to swing a golf club. Our secondary goal is creating a device that also functions in a way so that anyone can test it, including people who have full use of both arms. This secondary goal is necessary because upper extremity bilateral amputees are extremely rare. By designing a device that anyone can test, we can allot ourselves more time to make proper adjustments to our device in the future. Our final goal is to design a device that the amputee can independently attach and detach from the golf club, allowing them to play golf independently without the assistance of others.
The primary objective of this golf prosthesis project is to construct a device that allows bilateral amputees to swing a golf club consistently and effectively. In order to achieve this objective we developed secondary objectives for our solution process in order to satisfy the customer as best as possible. One secondary objective includes developing a device that bilateral amputees can use independently. Currently, there are no existing products that allow the user to play golf without personal assistance. This secondary objective will separate our device from any existing products. Our final objective is to develop a system that allows anyone to test the device, whether they are an amputee or have complete use of their arms. This simplifies the testing stage of our design, allowing us to make proper adjustments in less time.
After meeting with John Lawson and talking with Jim Taylor over the phone we realized how important their hooks are. Hooks, also known as terminal devices, screw into the end of prosthetic arms. Both John and Jim refer to their prosthetic hooks as their hands. Their hooks make their lives much easier. After taking this into consideration, another secondary objective was created which establishes that the user to must have full ability to use of one of their arms while using our device. By pursuing this goal we are attempting to insure that the user will be able to participate in other activities while golfing, such as drinking a beer or driving a golf cart.
We developed the customer requirements based on what the customer wants. Our customer requirements are listed in the Appendix in the QFD. The QFD, or house of quality, is a template used to develop the customer’s wants, how their wants will be met, competitive analysis based on their needs, and quantify how the needs will be met.
In order to establish our customer requirements we asked John Lawson and Jim Taylor what they would want out of a prosthetic golf attachment. As a result, a list of the top five customer wants were created including playing 18 holes of golf, participating in all aspects of the game, playing golf independently of others, and creating a device that was inexpensive and light weight. We developed nine customer specifications that encompass all of the customer wants. This list includes price, weight, ease of use, comfort, interchangeability, durability, reliability, aesthetics, and independent use.
After establishing the customer specifications in the QFD we developed a decision matrix to establish the targets of each specification as well as the risk and compliance. The list of all the design specifications, their targets, risks and compliances can be seen below in Table 1.
To determine the targets for each requirement we researched existing products. After researching we quantified each specification with units and tolerances such as two pounds for the weight and $200 for the price.
The risk assessment details how difficult it will be to meet each specification. The two high risk specifications include interchangeability and independent use. Interchangeability and independent use will be difficult to meet because they both rely completely on the user’s available motor skills and patience. We also want the user to be able to put on and take off the golf prosthesis independently and in fewer than 30 seconds in order for them to focus more on playing golf instead of spending time manipulating the attachment.
After reviewing our design specifications we narrowed the definition of our objectives by setting targets. The main objective focuses on the consistency and effectiveness of the golf swing. The specifications that define this objective are ease of use, interchangeability, and comfort. We defined ease of use as the user can make contact with a golf ball 9 out of 10 times. By achieving this goal we’ve established a foundation for the user to develop their own golf skills using the golf prosthesis. The target for interchangeability is to allow the user to take off and put on the prosthetic device in 30 seconds or less. This target gives the user freedom to use other prosthetic devices on the golf course to help them drive a golf cart or eat food. The last target that will help the user make a consistent and effective golf swing is to make sure they don’t need to contort their bodies into abnormal positions. If the user forces their bodies into awkward positions it will affect how well they’ll be able to swing a golf club. The device needs to be comfortable so they can play golf to their maximum skill level.