Safe Shots
Problem Statement
Diabetics with motor disorders using insulin syringes face safety and misdosing risks which could have serious effects.Â
Type 1 and 2 diabetics suffering from motor impairment thus need better mechanisms for accurately and safely loading their insulin syringes.Â
We thus sought to develop a device that holds the syringe and vial in place and automatically loads insulin to the desired amount.Â
Users/Purchasers
User: Diabetics suffering from motor disorders such as Parkinson’s and other neuropathies.
Purchaser: We aim for this to be sold directly to the consumer as an at-home device, but will also look to sell to nursing homes and hospitals.
State of the Art
Although there are no devices specifically geared toward diabetics with motor disorders, the existing insulin aid devices include manually filling the syringe, the insulin pump, and insulin pumps. However, these devices have various cons.
Manual Syringe & vial
Inaccessible to the motor impaired.
Needle safety is a concern.
Insulin Pump
Costly - $3000 - $7000
May have malfunctions
Risk of site infection
Insulin Pen
Not reusable
Not economical - $100-$300 per pen
Can't be used for all insulin types
Specifications
Some of the key specifications that informed the design of our product keeping our users in mind were safety, accuracy, ease of use, sustainability, size, and cost as outlined in the table below.
Prototypes
Various sorts of painful endeavors were done in order to progress our project to a satisfactory level. Many, many iterations are conducted and various changes were made throughout the processes as well.
Looks-like prototype
At first, we began with the looks-like prototype, approximately specifying the rough estimate of the size and shape our prototype should have by the end of the semester.
The looks-like prototype shows the dimensions of the prototype (which is mentioned in the specifications), and the basic mechanism of the syringe holder.
Basic works-like prototype
The basic works-like prototype implements a rack and pinion design. However, its implementation had too much friction and implemented glues for connections.Â
Furthermore, the works like implemented its functions in a large monolithic system, not allowing for a disassemblable, repairable design as well.
Additionally, the servo motor for integration did not have an effective method of feedback and set distance travel as well.
SolidWorks CAD
Front View
The isometric view of the prototype shows how the prototype will be assembled (from its parts).
360° view
The rotating solidworks model shows the various angle of the prototype and shows the overall assembly of all of the parts (sans arduino and base box).
Side View
The motor holder shows its securing screws on its structure and the motor along with the clearance added for the motor coupler as well.
Final Prototype - The Safe-Shot Loader 1.0
The final prototype was conducted through a new motor and newly designed parts.
The motor was swapped with a model with a Hall effect sensor and the entire components have been separated out into easily printable and controllable schematics, and drilled into a laser cut box to shorten the time required for production.
The syringe holder has been modified by adding slopes and grooves for accessibility.
The syringe plunger and the rack are now separated, and the rack now has a wider groove to allow a stronger grip on the gear.
The motor mount has been made tapped with heat sink inserts to allow a disassemblable design.
The plunger, rather than being in the same side as the rack location, has now been relocated to the opposite side to allow the rack to be away from public contact (for safety reasons).
The servo motor, now rather than just being a rental one, is a purchased one with an integrated hall effect sensor for maximum precision.
Assembled Prototype
The front view of the final prototype allows us to observe how the syringe holder and the plunger holder grip the syringe to draw.
The side view of the final prototype shows the location of the motor holder that rotates the rack and pinion (not shown) along with the location placed for the Arduino setup at a separate location as well.
The rack and pinion, which were not clearly pictured in this case, were purposefully hidden away from convenient reach due to reaching in serving as a hazard (i.e. hair), and with serving as a pinch hazard.
Demonstration
The demonstration shows the prototype operating with the needle being inserted, then the motor moving to a precise location to draw an exact amount into the syringe.
Testing and User Feedback
We tested our product by having two groups of students use the safe-shot loader under simulated shaking motor impairment and normal motor control as the control group. We reiterated the test for both manual syringe filling and the safe-shot loader and then tested for accuracy, safety, ease of use, and durability as outlined below.
Our results showed that our product performed way better than our baseline ie. manual syringe filling in terms of ease of use, safety, and accuracy for both the motor-impaired simulation and control group.
Ethics
Our main concern is needle safety. To mitigate risks, we are planning on offering free training for our users.
We conducted user surveys at a care facility to test accessibility.
We also need to follow FDA guidelines as it is a medical device.
Thorough testing is needed to ensure accuracy fell within 1 unit.
Sustainability
The diagram for sustainability as outlined below shows that our prototype is designed for longevity to minimize the impact of our product during its entire lifespan.
Okala Impact Factor
The table of the Okala impact factors shows that the primary impact of the product during its lifecycle is made within its manufacturing, thereby the priority for lifetime a worthwhile one for the environment.
Business Plan and Economics
While thinking about the economics and business plan of our product, we took into account the stakeholders that would be our key partners in developing, distributing, and using the safe-shot loader. We also included our customer segments, cost structure, and anticipated revenue streams as outlined in our business plan canvas below.
When it comes to the pricing of our product, we have taken into account our fixed costs and variable costs to determine the potential cost per unit of the safe-shot loader and estimate the market share that we would require to break even.
