Omnipod Insulin Management System

The Omnipod Insulin Management System is an all-in-one tubeless insulin pump designed by Insulet Corporation. The Omnipod System differs from other insulin pumps by being the only pump that consists of a completely tubeless “pod” that is wirelessly controlled by a Personal Diabetes Manager (PDM). The Omnipod PDM is essentially a Blood Glucose (BG) meter that also acts in compatibility with the pod as a wireless remote. The PDM controls everything a normal pump would do, such as deliver corrective doses and pre-program basal rates.^[1]

History of insulin pumps

According to Medscape LLC, The first insulin pump was made by Dr. Arnold Kadish in the early 1960s. Kadish’s design was very large, roughly the size of a marine backpack. After thorough testing of continuous subcutaneous insulin infusion (CSII) in the 1970s, insulin pumps were beginning to be seen as a possible alternative treatment for type one diabetics. The first commercial pump was known as the “big blue brick.” After its introduction in 1978, many companies began to develop their own version of the insulin pump. These early models were less than satisfactory to patients. The pumps did not have a foolproof way to deliver insulin safely, and some even lacked basic controls. In older models, a screwdriver had to be used to adjust an insulin dose. As a result of these problematic models, insulin pumps were still not used by most patients during the 1980s.^[2]

The use of pumps increased dramatically in the 1990s when medical device technologies improved drastically. This new technology brought safer insulin delivery, smaller pumps, and a more effective way to treat diabetes.^[3] Newer pumps, like the Omnipod, are now even operated by remote controls. Most insulin pumps today are fairly small, about the size of a pager, and they have helpful features such as bolus calculators that help a patient calculate an insulin dose. Most also have programmable memory, a multiple basal rate option, and safety lock features.^[4]

Insulet Corporation was founded in July 2000. In 2003, Insulet proposed the idea of the Omnipod and the company then received 501(k) approval from the Food and Drug Administration (FDA) to start producing the system commercially. Two years later, the FDA cleared the first version of the Omnipod System. 2005 was the first year the Omnipod was able to be found commercially, and only three years later all fifty US states sold and supported the new technology.^[5]

Pod mechanics

The “pod” portion of the Omnipod System is the small adhesive pump that is worn directly on the body. The base of the pod is entirely adhesive, and can be worn up to three days without being changed. After three days, the pod must be removed and re-applied to insure cleanliness and insulin affectability.^[6]

Insulin is delivered through a small port holding a soft cannula that is inserted into the person’s soft tissue. The cannula is automatically inserted, so the pump-user does nothing but press a button on the PDM. It enters the tissue at five 1000ths of a second. Surrounding the cannula, there is a vent that guarantees equal pressure with the surrounding environment.^[7]

Connected to the cannula is an independent reservoir that holds the insulin that will be delivered throughout a three-day period. The reservoir holds up to 200 units, but it can be filled with as little as 85 units. Since the insulin reservoir is “fully integrated,” it requires no changes or separate sets while wearing the pump.^[8]

The pod’s motor mechanism makes all actions possible inside the pod. The pod contains a microprocessor, which communicates with the PDM and converts those communications into electrical signals. Other mechanical parts within the pod include a shape memory alloy wire assembly (SMA), step sensor, and a motion sensor. The SMA wire assembly helps to rotate the driveshaft, which moves a piston into the insulin reservoir, delivering a dose through the cannula. Each turn the driveshaft makes delivers 0.05 units of insulin into the person’s bloodstream.^[9]

Insertion method

According to the manufacturers, The first step to setting up the Omnipod System is to sanitize the insertion site. This is most commonly done by using rubbing alcohol. Once the site is ready, the pod must be filled with insulin. Every pod set comes with a syringe to fill the empty pod with insulin. After the syringe is filled with the desired amount, the insulin can then be injected through the fill port on the bottom of the pod.^[10] The fill port has a one use only self-sealing septum. This ensures that insulin won’t escape through this port when it is being worn. Once the insulin is in place, the pod then primes itself to remove all air bubbles from the insulin reservoir.^[11]

When ready to attach pod, the patient peels off the plastic from the adhesive backing and the needle cover. They then stick the pod on to the desired site and secure the adhesive. The PDM will then guide the patient through specific prompts and will have them press certain buttons. After pressing ready to activate, the needle will then insert into the skin.^[12] When the needle has punctured the skin, it will retract and leave only the cannula imbedded in the tissue. The cannula enters at a 45 degree angle at a depth of 6.5 mm.^[13]

PDM functions

The Omnipod System’s Personal Diabetes Manager is a technologically advanced blood glucose meter. At the PDM’s core is a Freestyle-brand BG meter.^[14] Since the meter is built in, only one device needs to be carried. Also, no need to transfer BG records between devices or keep detailed logbooks. Built into the PDM is a logbook that can summarize past insulin delivery, BG numbers, and even past meals. It is also capable of downloading all data to the Copilot Health Management System if needed.^[15] The PDM also suggests bolus amounts by calculating insulin delivery based on what the patient’s BG level is and what their dosage settings are. If a user is unsure of the nutritional value of their meal, there is a digital food library containing common foods to help calculate dosages. Insulin on board (IOB) is also a very helpful tool found on the PDM that shows the amount of insulin remaining in the bloodstream. The PDM figures the IOB from previous insulin dosages when the bolus calculator is being used. Another feature of the PDM is its large color screen with an optional bright mode.^[16] This makes it very easy to see and use, even at night. It even has a test strip port light that allows people to easily check their BG in low-light conditions. One unique feature of the PDM is the fact that it is completely wireless. The pod will function normally and continue to deliver a basal rate of insulin without the PDM nearby, but they must be within five feet of each other to actually deliver an insulin dose.^[17]

Advantages

As observed by Springer Healthcare, The main advantage of the Omnipod System is the freedom it grants its users. Contrary to previous pump technology, it contains no external tubing. Insulin is pumped directly from the reservoir into the imbedded cannula, removing the need for a connecting tube. Having a patch style pump eliminates many worries that most pump wearers have to think about. The all-in-one style of the Omnipod allows the user to wear their pump at all times, even without clothing. They don’t have to worry about clipping it onto their belt or pants, so it can be worn at all times. Also, this means that any form of physical activity can also be performed while still wearing the pump; It is even waterproof up to 25 feet. Since the pump user doesn’t have to disconnect their pump for common activities, they will consistently receive insulin and have better control over their blood sugars.^[18]

Another advantage of the Omnipod is that it is much more accurate and discreet than other treatments. A diabetic that is currently using shots as a treatment has to manually calculate the amount of insulin they need, and draw up and deliver the dose themselves. Any step of this manual process can result in a lapse in accuracy. The Omnipod System is much more accurate because there is no manual insulin delivery, and The PDM calculates the exact dose needed, and the mechanisms inside the pod deliver the precise dose to the 0.05 units.^[19] On top of being extremely accurate, delivering a dose of insulin is much more discreet than other methods. Using shots, a person has to take out a vial of insulin along with a syringe in public. The Omnipod only requires the user to take out their PDM and press the required buttons. This process is much more discreet because the PDM resembles a phone or pager.^[20]

As researched by the Journal of Diabetes Science and Technology, The Omnipod System uses a computer-aided tool that helps users learn how to use their insulin pump effectively. A survey was conducted of 126 doctors or healthcare professionals who specialize in educating diabetics and training them how to use their insulin pumps. The results show that Insulet’s Omnipod Interactive Training helps to train effectively and gives patients a positive outlook on pump therapy. Usually, insulin pump companies have been the main source of pump information. The companies’ marketing plans and user manuals provided most of the information a patient would need. Using OmniPod’s Interactive Training provides a unique way for patients to learn basic self-management skills, standard methods of insulin delivery, and even provides corrective feedback as the patient learns.^[21]

Disadvantages

One disadvantage of the Omnipod is the insulin reservoir can only hold up to 200 units.^[22] If a patient uses less than 200 units in a three-day period, this isn’t a problem, but if a patient takes extremely high amounts of insulin, this may be an inconvenience. Since the pod can only hold 200 units, the patient may have to change the pod every two days instead of the standard three. This overuse of pods could also result in the patient having to spend more money on the Omnipod System, since the pods are disposable.^[23]

Since the pods are attached straight to the person’s skin, the pump itself protrudes directly off of the body. This bulkiness of the pod can be a problem when trying to wear certain clothing. The pump becomes visible when wearing tight-fitting clothes, or when wearing a bathing suit, which can be a problem for some people. Most issues with the size of the pump occur because it draws more attention to the pump, possibly having a negative effect on self-image.^[24]

Also, not being able to disconnect the pump is a huge disadvantage to some patients. Some people like the freedom to detach their pump without having to reinsert the cannula when they are ready to put it back on. The Omnipod takes this freedom away because the cannula component of the pump is fully integrated into the pod. This means if someone wants to take their pod off to wear a particular outfit or do a certain activity, they will have to dispose of the detached pod and apply an entire new set when ready.^[25]

Adhesive issues have also been reported by pod-users who are very physically active. Since the Omnipod is fully integrated, the pod’s position relies solely on a strong adhesive to keep it stationary. When a person is very physically active, they sweat more often. This may compromise the effectiveness of the adhesive by loosening the seal underneath the base of the pod and around the edges.^[26] Also, because all of the mechanisms and components lay directly on the skin, it feels heavier than the average infusion set. This can put excess stress on the adhesive, especially when exercising.

Pump comparison

A study was conducted by the Sansum Diabetes Research Institute where they recorded diabetic subjects’ activities, insulin intakes, and glucose numbers while they were using the Omnipod System. It was found that 90% (18 of 20) of subjects liked using the Omnipod over their current insulin pumps. They also preferred Omnipod’s cannula system much better because it automatically inserts itself.^[27]

The Omnipod system costs an average of 10 to 20% more than other systems, depending on how frequently patients change their infusion sets. Each initial unit costs over 640 U.S. dollars.^[28]

Diabetics wearing insulin pumps are required to change their infusion set often to avoid infection and other problems. Most people change their infusion site every 2 to 3 days depending on the individual’s amount of insulin used.^[29] The disposal of these insulin pumps and related items have posed a serious threat to the environment. Researchers with the American Diabetes Association have found that pumps with normal continuous subcutaneous insulin infusion (CSII) are much more environmentally friendly than “patch pumps,” like the Omnipod. The biggest concerns have been harmful chemicals found in the environment throughout water systems. The Omnipod device is much harsher on the environment because the metallic content is much higher than other pumps. Since the whole pump is being thrown away, the metallic contents, circuit boards, and batteries are all being disposed into the environment.^[30]

Like other insulin pump manufactures, Insulet offers a silicone skin and a belt clip case for their Omnipod PDM.^[31] Additional accessories are offered by several independent companies including: Bands 4 Life, Freed DM, and Sugar Medical.

Awards

As reported by Springer Healthcare, The OmniPod Insulin Management System has won the following awards:

(2006)Gold Industrial Design Excellence Award (IDEA) from the Industrial Designers Society of America

(2006)Medical Design Excellence Award (MDEA) for General Hospital Devices and Therapeutic Products

(2009)Edison Best New Product Award™ in the Science and Medical category^[32]

References