Accessible Syringe Dosing Device Megan Bowers Gabriel Goldman Robert Mock Karen Young BME 290 Project Statement September 27, 2004I. STATEMENT OF NEED In recent years, many independent adults have indicated a need for a method of accurately controlling the doses of their intravenous medications. Millions of people rely on self-medicating techniques that require the use of syringes. Those suffering from type II diabetes, and therefore are insulin dependent, or stroke patients, who use precautionary heparin injections, are some of the patients who most commonly use syringes. Self-dosing can be problematic for many people, especially those who are elderly, visually impaired, or hearing impaired, or suffer from arthritis, Parkinson’s disease, partial paralysis, or the loss of motor skills due to a stroke, heart attack, or other physical ailments. Clearly, there is a need for a reliable, easy-to-use, and inexpensive product to accurately fill syringes with insulin or heparin in a timely manner. Products currently on the market require patients to mechanically fill their syringes, using their fine motor skills to control the syringe mechanism. This method increases the risk of errant dosing by relying on the patient’s physical ability to perform the dosing correctly. The current products, therefore, do not accommodate patients that lack the fine motor skills necessary for correct use. The product described here will provide a digital self-dosing device that will accommodate many of the physical limitations mentioned above, while remaining affordable and competitive in today’s market.II. BASIC PRELIMINARY REQUIREMENTS This new product has several important basic requirements. It needs to be accessible for people who are hearing impaired, vision impaired, and who lack certain motor functions. Because most of the products already on the market accommodate those who are hearing impaired and vision impaired, the feature that will set this product apart from the others is that it will not require fine motor skills for operation. It must, of course, accurately dose the user’s medication to the nearest 0.01cc. The accessible syringe dosing device must also, as its title implies, be compact, easy-to-use, and cost effective. In order to design such a device, the team of project engineers will employ their knowledge in the areas of control, digital electronics, computer programming, instrumentation, and other essential branches of traditional engineering in addition to the application of the principles of biomedical engineering. III. BASIC LIMITATIONS There are certain problems in the design and analysis of the syringe dosing device that must be addressed. Reliability is perhaps the most prominent of these problems. It is necessary that the patient’s dose be correctly measured within 0.01 cc. Durability of the product will also be very important; this product must have the ability to withstand the force of a fall from approximately five feet onto a hard surface. Additionally, in terms of marketing, the cost of this product must be comparable to or lower than similar products on the market. One problem that may arise the design process is that of incorrect dosing due to the initial force of the device’s motor. If the motor initially jerks or slowly gets up to speed, this inconsistency will affect the reliability of dosing. Aside from this, the gear ratio needs to beprecisely determined in order for correct dosing. The gears need to be light, but have a very long and reliable life. Since the device will be digital, its programming must be devised and perfected. The program must accommodate the motors and gears of the device in order to ensure accurate dosing. Another dilemma that may be encountered during the design process is the matter of the power source of the device. There are many batteries to choose from, and because this product is a medical device, it must have a reliable power source. Employing a battery that is easy for the consumer to find in a local store would be ideal if feasible. When the battery needs to be changed, engineers should not need to be deployed; this instrument must have an easy outer compartment for easy changes. Lastly, the device should not function differently when the battery is low, and a low battery indicator needs to be created to warn user. Such an indicator may require additional circuitry. Ease of use is very important to syringe dosing. This medical instrument is being designed for a variety or persons with disabilities. Sound must be implemented within this device for the blind, requiring additional circuitry. The syringe dosing must not need more than minimal strength to use in order to accommodate people with arthritis or limited muscular or motor function. IV. CLIENTELE The principal clientele for this project as established by the Rehabilitation Engineering Research Center on Accessible Medical Instrumentation are Lloyd, Sophia, Arnold, Dave, and Wanda and her father Bob. These imaginary clients are designed to emulate the characteristics and conditions that a typical client of our product would exhibit. Each client is different,possessing unique needs that add to the general product stipulation. The following is a summary of the traits that we feel are most important when considering our design. Lloyd suffers from type II diabetes and therefore is interested in our product as a convenient method for dosing the syringes used for her insulin injections. She already has poor eyesight and is nearing 80 years old. In the coming years, her eyesight, hearing, and motor skills may further diminish. In terms of our design, this stipulates that our product should accommodate those who are elderly and who have poor vision. The product must be easy enough to use while not relying on sight to determine the dosing. Sophia, also around 80 years of age, is a victim of one large stroke and several smaller ones. Because of the risk of recurrence, she now uses heparin injections and therefore requires an accessible dosing mechanism. She has limited use of her right arm and therefore may have a hard time operating a device that requires either fine motor coordination or the use of both hands. The product should therefore accommodate these limitations by limiting, or perhaps eliminating, the need for fine motor functions. Arnold is also a victim of diabetes and