Beyond Omniseal® Blog

Powering Mobility in Our Daily Lives: Why Spring-Energized Seals Are Critical in Portable Insulin Pumps

Aug 28, 2019 / by Andy Li

More than 100 million Americans have diabetes or pre-diabetes, says the Center for Disease Control, and the World Health Organization estimated 422 million people worldwide had the disease in 2014, up from 108 million in 1980. Factors contributing to this growth include rising worldwide geriatric populations and more sedentary lifestyles.

Managing diabetes—with exercise, diet and medication—is a growing challenge for many; however, this challenge can be managed with the right medical equipment such as portable insulin pumps where design and manufacture are regulated by the Food and Drug Administration (FDA). Due to time and expense required to achieve FDA approval and improve precision of insulin delivery, manufacturers are driven to design more advanced insulin pump equipment. Using spring-energized seals is a critical part of this “smart” engineering technology that is powering mobility for end users every day and improving their quality of life.

How critical are these insulin pumps? Diabetes is one of the most common chronic diseases that is made more challenging because of its complexity and difficulty in treating. Insulin pumps mimic the normal function of the pancreas by delivering a specific amount of insulin at necessary time intervals (such as when blood sugar levels may be higher at mealtimes) to maintain blood glucose levels. Pumps can vary in the amount of insulin they hold, if they have a touch screen or other features, such as being waterproof. 

There are different types of insulin delivery systems such as traditional syringes, injection ports, insulin pens, conventional insulin pumps and patch pumps. Portable automated units are becoming increasingly more prevalent, giving people with diabetes greater mobility to treat and live with their disease in daily life. First introduced in the 1960s, it was not until 10 years later that the first portable insulin pumps came on the scene making greater mobility possible.

Due to increasing need, the insulin pumps market is estimated to be USD $8,264 million by 2025, an increase from USD $3,822 million in 2017 (a CAGR of 10.5%), says Research and Markets. While North America is currently the leading region in the global insulin pump market, given the high number of diabetic patients in the region, Asia Pacific is estimated to be the fastest growing market in the next five years due to increasing prevalence of diabetes and greater awareness of these devices, according to Orion Market Research Pvt. Ltd. With nearly 98 million people in India expected to suffer from diabetes by 2030, the market for portable insulin delivery devices in this country is expected to achieve an 8.7% CAGR from 2018 to 2025. Within Europe, Germany accounted for more than 25% of the diabetes care devices market in 2018.


Ensuring Patient Safety: How Spring-Energized Seals Are A Critical Part

Promising increased mobility and peace of mind, end users expect portable insulin pumps to be lighter and smaller as well as last longer between maintenance. Just as portable insulin delivery is a critical part in a person’s daily routine, so are the “inside” components that make the equipment function properly. Spring-energized seals are one of the mighty “hidden” parts that play an important role in device effectiveness.

The following shares several critical ways seals ensure safety and precision down to the microliter to keep the patient’s metabolism in balance:

1. Guaranteeing A Tight Seal: A tight seal is necessary to prevent leakage inside the device but also to prevent external elements entering the device.

  • Seals play a critical role to ensure greater dosing accuracy. Obtaining the right level of blood sugar control with insulin injections is an essential function of portable insulin pumps. If insulin or other fluids come into contact with the inside of the insulin pump’s tubing connectors, it could temporarily block the vents that allow the pump to properly prime. Patients with too much insulin may eventually become hypoglycemic (and experience palpitations, sweating, anxiety, and in extreme, prolonged cases, dizziness, confusion and coma). With too little insulin, high blood glucose levels can cause glucose to spill into urine causing more frequent urination, thirst, dehydration, confusion. This can lead to sickness, coma, even death if not treated.
  • Using an effective, reliable seal also ensures moisture intrusion protection. Since patients continually carry or wear the device at all times, in cases when they bathe, swim or exercise, a tight seal is necessary to prevent fluids from entering electrical parts.

2. Providing Long Life and Low Friction: Seals provide low friction necessary to keep the device working properly. If the friction gets too high, malfunctions can occur. Seals also have a long life, which is ideal for this device worn and used every day.

3. Being Dry Running: Frequently, these seals also need to be dry running, which is a huge factor for medical, pharmaceutical and other applications that have stringent demands for product purity and where contamination of the process is a priority. Dry seals require less maintenance than wet seals because there is no lubricator to maintain and refill when the level is low.

4. Having Material Compatibility: Materials used must also be compatible with insulin and other fluids. Materials that are FDA-approved can be an added plus.


Using The Right Precise Fit Sealing Solution Makes THE Difference

Elastomer o-rings are often used in insulin pumps. However, a major drawback of these parts is that they are often unable to maintain a consistent seal over time and may be more abrasive and susceptible to friction and leaks. This can happen if o-rings around the plunger become weak or damaged due to not being properly lubricated during manufacturing.

Conversely, Omniseal Solutions' Omniseal® 400A spring-energized seals provide a higher level of performance with a tighter seal and low levels of friction, to significantly reduce or prevent leakage. These spring-energized seals recently passed rigorous testing for a key medical customer’s requirements. The customer was challenged with high frictional force, causing the entire insulin injection pump system to consume too much energy. Omniseal Solutions’ team was able to solve this issue and provide a low friction sealing solution as well as optimize tooling structure to reduce the possibility of any design eccentricities.

The Omniseal® polymer seal is ideal for insulin pump applications along with other medical device applications such as portable oxygen concentrators as it offers high performance in dynamic applications. They are often used in insulin pumps to provide more dynamic run-out and very low friction at both high and low pressures. They address pressures from UHV to 100 MPa, temperatures of -50 to +350 °C and maximum speeds of 1 m/s. These seals feature a Fluoroloy® jacket, designed with a flange on the ends, energized by a corrosion resistant, v-shaped cantilever spring. 

With most hardware in insulin pumps comprised of plastic, Omniseal Solutions™ often leverages their Fluoroloy® A01 PTFE material, which is soft and has low friction in the jacket of these spring-energized seals. This custom PTFE material offers excellent chemical resistance, limited wear resistance, is FDA compliant and has good cryogenic properties.

These seals can also be supplied with an FDA-approved grade of RTV silicone filled into the spring cavity. Although seals in portable insulin pumps do not tend to have direct contact with blood or a person’s body, it is advantageous for components in medical equipment to have FDA certification. This FDA-approved material ensures contaminants are not in the spring cavity, allowing the seal to confidently be used in medical and life science applications.


A Leader in Life Sciences Seals & Polymer Components

Omniseal Solutions™ has been supporting life sciences partners for over 30 years with strong design engineering expertise and research and development capabilities. They have been at the forefront of the healthcare industry by teaming with OEMs that require the lowest friction and most reliable components for use in portable devices but also analytical in vitro equipment, microsurgical tools, and numerous other life science devices.

In addition to its Omniseal® spring-energized seals, Meldin® and Rulon® materials are also frequently used in healthcare and medical equipment.

The Meldin® solution is available in thermoset polyimide materials and a diverse array of engineered thermoplastic products based on polyphenylene sulfide, polyetheretherketone and polyamideimide. Each series is designed with unique characteristics and has been proven for specialized applications where high thermal resistance and good mechanical properties at high temperatures are required.

The Rulon® solution includes blended PTFE-filled materials available in hundreds of formulations, which can be custom designed into bearings, piston rings, cup seals, wear components and other critical parts to offer a low coefficient of friction and high wear in extreme temperature and pressure ranges.

With its Omniseal® spring-energized seals and other polymer materials used in applications that directly impact patients’ daily lives, such as in portable insulin pumps, Omniseal Solutions™ is focused on giving customers and their end users the freedom, motion and reliability they deserve.

Will you be attending Medical Technology Ireland from September 25 to 26? Come see us at booth #67 or contact us today to set up an appointment to learn more about Omniseal® spring-energized seals and other polymer solutions in life science applications.

Topics: Life Science

Andy Li

Written by Andy Li