Target Specifications
Introduction
After developing a list of customer needs, the next step is to examine competitive products to determine how the current state of the art addresses the customers' needs. By examining existing products and quantifying their ability to satisfy customer needs, the group can gain a better sense of what their product must achieve in order to meet the needs of the customers in a way that exceeds the competition.
Identification of Competitive Quantitative Performance
Products already on the market similar to the device to be created were examined. In general, competitive products do not meet perceived customer needs. The competitors' products aid the dosing but do not serve people with disabilities. The products require two hands in order to prepare the device. In addition, some products also have small components that make it hard for people with tremors or limited use of their hands to operate the product. A major goal of this project is to aid people with vision and hearing impairments. When investigating currently marketed devices, it was apparent that these impairments were not taken into consideration in their design. The only features some products incorporate to aid this problem are beeps or clicks. The devices that incorporated aids for people with vision impairments only had larger numbers for communication. Even those with a small amount of aid for vision and hearing impairments tended to cost a considerable amount, often over $100. Making syringe dosing accessible to those with disabilities at a reasonable cost was a main objective when defining specifications.
Moreover, nearly half the products on the market require proprietary syringes and needles. This makes the product more costly for the person to maintain. A major specification of the product is that it utilizes standard syringes and bottles. Few products work when the patient needs a mixed dose of rapid and long-acting insulin. In order to receive both doses, diabetics have to inject themselves twice. Most competitive products required a relatively large amount physical exertion.
Below is a list of metrics that were gathered that could be used to quantify how well a product addresses customer needs. For each metric there is an associated importance ranging from one to five, with one repesenting the least amount of importance and five representing the most. These metrics were then used to guage how well other products meet the needs of the customers. Based on these findings, an ideal values for each of the metrics were determined, and these values were used as design input for the syringe dosing device.
| Metric No. | Metric | Importance | Units | Ideal Value |
|---|---|---|---|---|
| 1 | Operation with only left or right hand | 4 | Binary | Yes |
| 2 | Dosing accuracy | 5 | Unit (0.01 cc) | <1 |
| 3 | Total mass | 2 | lbs. | 5 |
| 4 | Audio level | 5 | dB | 0 - 80 |
| 5 | Syringe sizes | 4 | List(cc) | 1 |
| 6 | Uses standard bottle | 4 | Binary | Yes |
| 7 | Insulin storage capacity | 4 | cc | 20 |
| 8 | Visual display | 5 | Binary | Yes |
| 9 | Simple user interface | 4 | Binary | Yes |
| 10 | Bottle storage | 2 | Binary | Yes |
| 11 | Time to prepare dose | 4 | Seconds | <60 |
| 12 | Unit sale price | 5 | US $ | <200 |
| 13 | History of dosing | 3 | Binary | Yes |
| 14 | Error notification | 4 | Binary | Yes |
| 15 | Bolus Range | 4 | Unit (0.01 cc) | 1 - 100 |
| 16 | Audio output | 5 | Binary | Yes |
| 17 | Power | 2 | Binary | Yes |
| 18 | Dose calculation | 2 | Binary | Yes |
| 19 | Mixes bottles | 4 | Binary | Yes |
| 20 | Maximum leakage currents | 5 | uA | 0 |
| 21 | Time limits on operations | 3 | Binary | No |
| 22 | Qualifies as durable medical equipment | 1 | Binary | Yes |
| 23 | Simultaneous actions required | 3 | Binary | No |
| 24 | Ability to correct an input misdosing | 5 | Binary | Yes |
| 25 | Syringe storage | 1 | Binary | Yes |
| 26 | Multiple insulin types | 3 | Binary | Yes |
| 27 | Regular maintenance required | 2 | Binary | No |
| 28 | Controls are easily accessible | 5 | Binary | Yes |
| 29 | Removes bubbles | 5 | Binary | Yes |
Justification for Specifications
When determining the target specifications, it was imperative to understand how these specifications for the product design would help to fulfill our customer's needs. The most important customer needs were presented by Rehabilitation Engineering Research Center (RERC) as part of the design competition for this device. In general, our device needs to be able to accurately dose a syringe to one unit increment (0.01cc), and be able to be operated by individuals with a variety of disabilities. Metric 1 is the first to deal with these disabilities. Any person who may have tremors in one hand, or had a hand amputated, or has lost feeling in one of their hands will need this device to be equally easy to operate using only their left or their right hand. Metrics 4 and 16 indicate the need to include not only an audio output, but one with a variable volume level, so that those that are hard of hearing or blind will have a way to operate the device. Also, for individuals who are hard of hearing, Metric 8 specifies the need to include a visual display. Both of these outputs (audio and visual) will help accomplish Metric 13 (history of dosing), 14 (error notification), and 18 (dose calculation) by communicating with the user. Metric 13 will also help out individuals who have a bad memory as a result of old age or Alzheimer's disease, by keeping a record of past doses.
All-in-all, this device needs to be easy to use for anyone and everyone. Controls need to be accessible (Metric 28), no simultaneous actions by the user should be required, which could be confusing(Metric 23), and the device should of course have a simple, easy to understand interface(Metric 9). While the goal was to make the device easy to use, it is also necessary to make sure the device functions as needed; that is, to accurately draw varying doses of insulin from a standard size bottle into a standard size syringe quickly and simply. This seemingly straightforward goal encompasses Metrics 5, 6, 7, 10 ,11, 15, 19, 25, 26, and 29.