Research Paper Doctorate 4,199 words

Insulin Pump Technology for Juvenile

Last reviewed: January 21, 2005 ~21 min read

Insulin Pump Technology for Juvenile Diabetics

This is a paper about juvenile diabetics and insulin pumps. There are seventeen references used for this paper.

Juvenile diabetes is one of a number of diseases which affect children throughout the world that have no known cure. It is important to examine the disease and how it affects the human body, as well as possible future technology aimed at controlling the disease.

A method which needs to be explored is the insulin pump, and what innovations are currently being implemented in order to improve its effects. It is crucial to understand the history of the pump, how it works, and the results of improvements made to the pump over the years.

Juvenile Diabetes

Juvenile diabetes, also known as Type-1 diabetes, occurs when insulin can not be produced by the body, which is "necessary for the body to be able to use sugar. Sugar is the basic fuel for the cells in the body, and insulin takes the sugar from the blood into the cells (http://www.diabetes.org/type-1-diabetes.jsp)." Juvenile diabetes is a serious condition, however with proper insulin management, it is possible for patients to "live long, healthy, happy lives (http://www.diabetes.org/type-1-diabetes.jsp)." There are currently between "750,000 and 1 million Americans who are dependent on insulin, with 30,000 new cases diagnosed each year (http://www.hypertension-consult.com/Secure/textbookarticles/Primary_Care_Book/75.htm)."

Complications From Diabetes

Juvenile diabetes can be attributed to a number of conditions in the body, including "hyperglycemia, hypoglycemia, ketoacidosis and celiac disease. Some serious complications of juvenile diabetes are heart disease (cardiovascular disease, blindness (retinopathy), nerve damage (neuropathy), and kidney damage (nephropathy) (http://www.diabetes.org/type-1-diabetes.jsp)." Diabetes can reduce blood circulation to the foot, which can result in severe complications and in some cases, amputation.

Managing Diabetes

In order to reduce the conditions and complications of diabetes, it is important to closely monitor the body's blood glucose level. The patient should strive to maintain a safe glucose level which is close to that of a nondiabetic. An "A1C test provides a patient with information concerning his or her average blood glucose control for the previous 2 to 3 months, letting them know how well their diabetes treatment plan is working (http://www.diabetes.org/type-1-diabetes.jsp)."

There are a variety of products available to help monitor and regulate a person's glucose levels. Blood glucose meters and their supplies are an important parts of glucose monitoring. Tests are available which detect ketones, albumin, and glucose in the urine. Insulin can be administered with "syringes, insulin pens, jet injectors and insulin pumps.

Maintaining Glucose Levels person with juvenile diabetes "has very little or no endogenous insulin production, resulting in brittle glucose values ranging from very high values to hypoglycemia (http://www.medscape.com/viewarticle/488996)." Diabetics need to strive to maintain a glucose level of "HbA1c less than 6.5%, a fasting glucose below 100 mg/dL, postprandial glucose below 140 mg/dL, and the avoidance of hypoglycemia (http://www.medscape.com/viewarticle/488996)."

This is a complicated process which must be adjusted based on a person's glucose data. In order to maintain a correct glucose level, the person must monitor their blood glucose levels prior to meals, and receive daily injections or use an insulin pump. The "benefits of tight control, in terms of prevention of complications, are worth the effort, the risks and the expense. These intensive insulin regimens should be available to all juvenile diabetics and should be the standard of care (http://www.medscape.com/viewarticle/488996)."

Initial Use of Insulin

In the 1920's, "Banting and Best revolutionized the treatment of diabetes with the extraction of insulin from animal pancreases. Supplemental insulin administration remains the treatment for insulin deficiency, which characterizes juvenile diabetes (http://www.medscape.com/viewarticle/488996)."

Insulin Therapy

While insulin therapy is important to maintain glucose levels, there can be problems with the dosage and timing of administering insulin. Over the years, advances have been made in insulin therapy such as the creation of the synthetic insulins-lispro and aspart. These are "short-acting insulins which are quickly absorbed from subcutaneous tissue and disappear more quickly, making it possible to give a dose much closer to mealtime than regular insulin, and there is less risk of hypoglycemia at a later time. It is also easier to give larger doses than with regular insulin, creating higher peaks to deal with postmeal glucose levels with less risk of hypoglycemia (http://www.medscape.com/viewarticle/488996)." Insulin pumps are able to use lispro and aspart insulins to efficiently maintain glucose levels.

Types of Devices

There are different types of devices which can be used to infuse insulin into the body. These devices, which are "classified as a closed or open loop system depending on whether they have a glucose sensor or not are:

Insulin pumps- open looped.

Computer-controlled insulin pump with sensor- closed looped.

Hydrogels implanted artificial drug delivery system providing chemical feedback between blood glucose and insulin release from a nonrefillable reservoir of limited capacity- closed looped.

Transplantation of insulin producing tissue (islets) and the bioartificial pancreas, employing the natural beta-cell both for glucose-sensing and insulin delivery (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

Continuous Insulin Infusion

An insulin pump is used to administer "continuous subcutaneous infusion of insulin (CSII) in terms of permitting the programmed timing of insulin levels. These pumps permit preprogrammed delivery of basal insulin profiles as well as quick premeal infusion of bolus insulin doses (http://www.medscape.com/viewarticle/488996)."

The insulin is pumped into the body via an "indwelling subcutaneous catheter, which must be changed every 48-72 hours. Implanted pumps deliver insulin directly into the peritoneal cavity and then to the portal venous system, thus allowing a first pass in the liver before the peripheral circulation, similar to that of normal physiological pancreatic insulin. These catheters have a tendency to clog over time, and the need to change the internal catheter surgically on an annual or more frequent schedule has constituted an impediment to distribution of the implanted pumps (http://www.medscape.com/viewarticle/488996)."

Early Insulin Pumps

The hope of ending continuous subcutaneous injections resulted in the development of insulin pumps. The initial pumps provided the possibility of maintaining correct blood glucose levels in juvenile diabetics. When the pumps were introduced over 20 years ago, they were cumbersome and not well received. However, the "development of new, robust and easily programmable insulin pumps has led to readier acceptance of this therapy by physicians and patients (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

The first insulin pump was "approximately the size of a microwave oven and performed exactly the same functions that the beta cells did in a non-diabetic pancreas. The Biostater measure blood glucose levels and dispensed insulin into the blood stream every five minutes and because of its size was used to treat diabetic ketoacidosis, as well as diabetes related research studies (http://www.nfb.org/vod/vsum0001.htm)."

The portable insulin pump was first considered when Yale researchers explored the possibility of an individual monitoring their own glucose levels and adjusting the pump as needed. The first portable pump was originally one used for chemotherapy, since the concept was "taken from the way cancer patients were given their medicines, weighed over a pound and used a large syringe placed on the outside of the pump. The early pump was about the size of an aerosol can, only wider and rectangular, had dials located on the outside and blinking red LED lights. The pump delivered diluted regular insulin at a constant rate and the user pumped in extra insulin based upon meal times and blood glucose levels (http://www.nfb.org/vod/vsum0001.htm)."

Since the pumps were based on those used in chemotherapy, the manufacturers of chemotherapy pumps made the first pumps specifically used for insulin. There were differences in the two pumps, as the ones for insulin were "smaller and lighter, with the syringe mechanisms hidden in a covered compartment. These pumps were much thinner and sturdier, which gave them distinct advantages over the converted chemotherapy pumps. The pump was more cosmetic for the user, and allowed the user to be more active, with less caution, to avoid damaging the pump during activities (http://www.nfb.org/vod/vsum0001.htm)."

There was a flaw in the initial pump, which was the "user still had to dilute U-100 insulin into concentrations like U-18 or U-36 with saline and eventually the same fluid that insulin is dissolved in. This was due to the fact that the pump design was based upon how chemotherapy drugs were delivered and not how hormones such as insulin were produced and used in the body (http://www.nfb.org/vod/vsum0001.htm)."

How an Insulin Pump Works

The insulin pump itself is "essentially a device that holds a syringe filled with insulin, and the delivery of the insulin is exquisitely controlled by a mechanism that pushes the plunger of a syringe down to infuse insulin into the subject via an infusion set. The infusion set is attached to a straight or bent needle or a Teflon catheter that has been designed for optimal function and comfort. This is inserted into the subcutaneous tissue, most often of the abdomen, but potentially of the upper legs or arms, or of the buttocks (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

Advantages of Insulin Pumps

There are a number of advantages to using an insulin pump. These advantages "include:

More physiologic

Less variable insulin absorption

Better match between insulin and food

Greater lifestyle flexibility

Easier to travel - improved portability (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

Fewer injections.

Flexible eating and schedule.

Match insulin doses precisely to need.

Correct the Dawn Phenomenon.

Less hypoglycemia and hypoglycemia unawareness.

Reduces insulin quickly for exercise.

Provide better health through better control (http://www.diabetesnet.com/diabetes_technology/insulin-pumps-advanced.html)."

Problems With Pumps

While the insulin pump has many advantages, it is not immune to problems. One of its basic problems "is the potential alteration of the administered insulin by motion, contact with pump surfaces and changes in temperature. Insulin forms aggregated macromolecules that have reduced insulin activity and tend to precipitate in the catheter, causing obstruction. Insulin must be buffered and treated with additives to increase viscosity, thereby improving it physical stability (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf).

The pump has another problem, especially prevalent in the initial models, which is "encapsulation by the dense fibrous tissue of the implant. Early versions were plagued by problems with fluid leakage into the system, short battery life, insulin blockage of the pump or catheter and tissue blockage of the peritoneal catheters and adhesions (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

Risks Involved With Insulin Pumps

While insulin pumps have proven to be beneficial, there are risks involved in this form of therapy. Due to the fact "insulin pumps use the very fast-acting Lispro insulin which only lasts three to four hours after injection, Diabetic ketoacidosis (DKA), a life-threatening condition caused by lack of insulin, becomes a real possibility if the pump stops delivering the required amount of insulin. DKA could happen if the pump tubing becomes blocked or comes out from under the skin, or if the pump cartridge is allowed to run out of insulin. If the problem isn't discovered for several hours, blood sugars will rapidly rise and ketones will appear in the urine (http://www.diabetes.ca/Section_Membership/DialogueWin00-insulinpump.asp)." An individual can prevent this condition, however, by frequently monitoring their blood glucose throughout the day.

Another risk involved with insulin pumps is skin infections, which can become a serious condition in a diabetic. An infection can occur at the catheter's insertion site since the "pump catheter or tubing stays in place under the skin. This can be prevented in most people by using good technique when changing the catheter, taking care to keep the site clean, and changing the catheter frequently (usually every two to three days) (http://www.diabetes.ca/Section_Membership/DialogueWin00-insulinpump.asp)."

Pump Users

When the pumps were initially introduced, users had to undergo "psychological testing, stay at least one week in a hospital, and be dedicated to monitoring their blood glucose (http://www.nfb.org/vod/vsum0001.htm)."

Today's users find they are unrestricted in what activities they can participate in, due to innovations such as watertight cases for swimming.

Insulin pumps are so light and small that users are able to wear them without the knowledge of others.

Choosing to use the insulin pump is a personal decision and should be fully discussed with one's healthcare provider. After discussing the use and care of the insulin pump, as well as the benefits and risks involved, the patient should then be able to make a truly informed decision.

Research Data clinical trial provided evidence that "insulin pumps are one of the best methods for near-normal insulin delivery. Approximately half of the adults and a quarter of the teens used insulin pumps at some time during the trial, which resulted in patients intensively managed experienced a lowering of glycated hemoglobin levels and a reduction in long-term diabetes complications when compared to those treated with conventional protocols (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

Insulin Pumps and Children

Insulin pumps have proven to be beneficial to diabetic children of all ages and their parents. Parents of preschool children "report less anxiety about their kids who use the devices compared with families dealing with insulin injections.

While control was equally adequate for kids using continuous infusion and for those using injections, those receiving the injections produced significantly more for their parents. A trend towards less parental anxiety was evident for pump users (http://www.medicalpost.com/mpcontent/article.jsp;jsessionid=ABIDHKOKILJF?content=20040607_194326_5696)."

Insulin pumps have been used in children as young as 5 weeks old. While the pumps are effective in controlling blood glucose levels, the concentration of insulin makes it necessary for a health care professional to monitor its dosage frequently (http://www.insulin-pumpers.org/pkids/youngest.shtml).

The daily injections that diabetic toddlers must endure can be practically be eliminated by using the insulin pump. Another benefit is better dosing, since the "small amounts of insulin needed to maintain glucose in the ideal range make the dosage delivered by a pen or syringe too imprecise (http://www.insulin-pumpers.org/faq/askexpert01.shtml)."

While it was initially thought that newly diagnosed diabetics could not deal with the changes in their lifestyles and the pump at the same time, new research is proving this to be false. A study with pediatric patients has found that "all the newly diagnosed patients and families readily learned the pump mechanics, having no more difficulty than patients who had type 1 diabetes for longer periods; all patients achieved excellent metabolic control without significant hypoglycemia, with blood glucose levels in the near-normal range through the first six months; all patients expressed satisfaction with pump therapy (http://www.insulin-pumpers.org/links.shtml)."

Today's Pumps

Today, for type 1 diabetes, "insulin pump therapy remains the optimal approach with the most flexibility, especially with the ultra-fast-acting analogs lispro and aspart (http://www.medscape.com/viewarticle/488996)."

There are three main brands of insulin pumps used today. These brands are "Disetronic Medical Systems, MiniMed Technologies, and Animas (http://medind.nic.in/ibi/t02/i6/ibit02i6p379.pdf)."

The pumps used today are "smaller, easier and safer to use, and more durable than their predecessors. Current models have electronic memory, multiple basal rates, several bolus options, a safety lockout feature, and a remote control, while modern infusion sets have soft cannulas and quick-release options. The historical evolution of external pumps has made CSII a safe and viable alternative to MDI (http://www.postgradmed.com/issues/2002/05_02/bode3.htm)."

Pumps in use today rely on batteries which are easily accessible and last longer than those used in older models. They are able to dispense almost all types of insulin and have alarms "which warn the user of clogged tubing and low power supplies. The newer pumps are able to store important data concerning administration and alarms, have lighted screens (for sighted users in dark locations) or audio cues for those users who have a visual impairment (http://www.nfb.org/vod/vsum0001.htm)."

Medtronic Minimed

Medtronic MiniMed was founded in 1949, and "since developing the first wearable external cardiac pacemaker in 1957 and manufacturing the first reliable long-term implantable pacing system in 1960, Medtronic has been the world's leading producer of pacing technology, and is the world's leading producers of insulin pumps and continuous glucose monitoring systems. Medtronic, Inc., headquartered in Minneapolis, is the world's leading medical technology company, providing lifelong solutions for people with chronic disease (http://www.minimed.com/patientfam/pf_ipt_paradigm_pump_overview.shtml)." The company's main line of insulin pumps is the Paradigm® Platform.

Paradigm® Insulin Pump

The "Paradigm® insulin pump is not just an insulin pump, it is a platform for ongoing innovation, designed to be upgraded like a computer. Only this platform has three generations of innovation, with each new generation built on the foundation of innovations that preceded it, providing ongoing improvement in flexibility and control (http://www.minimed.com/patientfam/pf_ipt_paradigm_pump_overview.shtml)."

The three generations of the platform are:

GENERATION 1 (2002)- Platform concept unveiled. An E-Z PATH™ menu and multiple basal and bolus options provided improved effectiveness and ease of use.

GENERATION 2 (2003) - The Paradigm® 512/712 insulin pump. 'Smart pump' features introduced such as the Bolus Wizard® Calculator, which does the diabetes math for an individual to suggest a bolus amount.

GENERATION 3 (2004) - The Paradigm® 515/715 insulin pump. Innovations include the Web-based Medtronic CareLink® Therapy Management System, which charts A1C, BG, carbohydrates and other trends to help optimize therapy (http://www.minimed.com/patientfam/pf_ipt_paradigm_pump_overview.shtml)."

The Paradigm® 515/715 Insulin Pump

MiniMed utilized research over the past 20 years to create its Paradigm® 515/715 insulin pump. The pump, which is available in four colors, is designed to "emphasize ease of use, optimize safety, and ensure continuous, flexible insulin delivery (http://www.minimed.com/patientfam/pf_ipt_paradigm_pump_overview.shtml)."