Automated Syringe Dosing DeLorme, J.J., Hanson, E.E., Weisshaar, C.L., Wentland, A.L. BME 400 Department of Biomedical Engineering University of Wisconsin-Madison December 8, 2004 Advisor Willis J. Tompkins, Ph.D., Professor Department of Biomedical Engineering Abstract Many people, especially elderly individuals, have afflictions along with diabetes, including poor eyesight, tremors, loss of dexterity, arthritis, and multiple sclerosis. These disabilities make it difficult for patients to measure and administer medications with a syringe. We have developed a device that electronically drives the plunger on a standard syringe, reducing the dexterity normally needed with dosing a syringe. We have constructed a prototype that demonstrates the feasibility of driving the syringe on a screw-based system with a bimodal stepper motor. In our next prototype, the device will be handheld and lightweight. We will incorporate a user interface consisting of a digital display and numerical keypad.Syringe Dosing 2/24 Table of Contents Page Abstract 1 Table of Contents 2 Problem Statement 3 National Student Design Competition 3 Background 3 Current Products 5 Contacts 7 Design Constraints 7 Design Approaches 8 Design Evaluation 10 Our Chosen Design 11 Syringe Dosing Device: Operation 12 Prototype 12 Construction of the Prototype 13 Syringe Dosing Device: Advantages 14 Syringe Dosing Device: Disadvantages 15 Syringe Calibration and Preliminary Testing 15 Future Work 16 Ethical Considerations 17 References 18 Appendix A: PDS 20 Appendix B: Expenses 24Syringe Dosing 3/24 Problem Statement Our goal is to develop a syringe delivery device that uses standard 1 cc syringes (BD Ultra-FineTM Needles [1]) and sets the dosage on those syringes within 0.01 cc accuracy. This device should minimize the dexterity typically needed with dosing a syringe. This device should be easy to use for elderly patients and those with poor eyesight. Ideally, this machine would be suited to patients who use syringes on a daily basis, such as those suffering from diabetes. Patients afflicted with maladies in addition to diabetes, such as neuromuscular disorders and poor eyesight, would also benefit greatly from this device. National Student Design Competition This project is part of the 2004-2005 National Student Design Competition, an undergraduate competition funded by the Rehabilitation Engineering Research Center on Accessible Medical Instrumentation [2]. In conjunction with Marquette University, Professor John Enderle of the University of Connecticut chairs the competition. The competition is open to students predominantly in biomedical engineering and industrial design. Student teams have a choice of three projects: a weight scale, a syringe dosing device, or an ergometer, all to assist patients of diabetes, obesity, paralysis, and neuromuscular disorders. At the University of Wisconsin – Madison, another team is working on an ergometer [3] while our team is working on a syringe dosing device. Background Diabetes is one of the leading causes of disability in the United States, causing dementia, low testosterone levels in males, excessive thirst, frequent urination, fatigue, changes in vision, blindness, stroke, nerve damage, and the need for amputation [4, 5]. Diabetes is typically treatedSyringe Dosing 4/24 with insulin injections, where the amount of insulin is determined by eating habits, exercise, and ultimately a patient’s blood glucose level. While the changes in vision make it difficult for patients to see and set the dosage on the syringe, elderly diabetes patients commonly acquire neuromuscular diseases, albeit unrelated to diabetes. Nevertheless, these diseases make it difficult for patients to control syringes. Type 2 diabetes is the most common form of diabetes, affecting 18.2 million people in the United States alone. This type is found in 90-95% of the diabetes patients [6]. Those most often afflicted with this disease are older people. The Center for Disease Control [6] has predicted that the number of American diabetes patients will increase as Baby Boomers grow older and more sedentary. Type 2 diabetes is characterized by a high blood glucose level, a high insulin level, and a resistance to insulin (Figure 1). Contrary to type 1 diabetes, where insulin does not get produced in proper quantities, type 2 diabetics cannot use their insulin effectively [5]. A person with diabetes must take daily precautions to maintain optimal health. These include healthy eating, exercise, and blood glucose testing. Blood glucose testing will tell if the blood sugar levels are too low (hypoglycemia) or too high (hyperglycemia) [4]. Irregular blood sugar levels can cause illness, dizziness, nervousness, confusion, fainting, and/or impaired judgment [4]. Depending on the blood sugar level, insulin may be administered. Figure 1. Type 2 Diabetes. In this disease, users develop a resistance to insulin, and therefore, blood glucose levels rise [7].Syringe Dosing 5/24 The injection procedure should be done as recommended by an endocrinologist and is as follows [8]: 1. Wash hands and area where injecting (usually a fatty subcutaneous tissue area such as the stomach). 2. Wash medicine bottle top with cotton ball and alcohol. 3. Draw air into the syringe equal to the volume of fluid needed. 4. Insert needle into medicine bottle and depress plunger, pushing all air out of the syringe. This action creates a vacuum and allows for easier and smoother filling and delivery. 5. Invert medicine bottle and fill syringe, making sure the needle is not exposed to air. Air bubbles in the barrel will lead to an incorrect amount of medication. 6. Once the syringe has been filled to the proper amount, keep the bottle and syringe upside down and flick the syringe barrel. This moves air bubbles that may have formed at the top of the syringe. 7. Push the plunger to move the air bubbles into the vial. 8. Check medication dosage. 9. Insert needle into skin at a 90-degree angle and deliver medicine at a slow, steady rate. All medication should be released within 5 seconds. 10. Dispose of needle properly. It is evident that this is a complicated and involved procedure, requiring a fair amount