Wearable Medical Devices CAD Design

The majority of people born before the year 1900 did not live past the age of 50. In the 20th century, life expectancy increased dramatically, and today, life expectancy is over 80 years in many developed countries. It is estimated that people over 85 years of age comprise about 8% of the world population. However, the cost of health care continues to rise, and the expected large number of the elderly who will need health care could severely stress the health care systems of many nations.

Although it is welcome news to have increased life expectancy, living to a good old age will not be meaningful without good quality of life. Old, diseased or disabled poor senior citizens create burdens for care givers and families, and they increase the cost of health care and insurance for the entire population. One way to maintain good quality of life for the elderly is to find efficient and inexpensive methods for monitoring their health. Doing so makes it easier to take preventive measures to combat diseases, and toproactively treat diseases and ailments before they become difficult and expensive to handle.

The following is a partial list of steps which could be taken to increase life expectancy:

  • Reduce the transmission of infectious and parasitic diseases;
  • Immunize against smallpox, polio, measles, and major childhood diseases;
  • Improve living conditions, provide clean water, and nutritious diets;
  • Provide health awareness and education in order to minimize exposure to health risks such as toxic substances, smoking, alcohol consumption, poor diet, and lack of exercise;
  • Fund the development of advanced drugs to fight and treat diseases;
  • Provide health monitoring, health management, and injury control.

The last item, “Provide health monitoring, health management and injury control” uses modern CAD-related technology in the form of wearable medical devices, and it is the focus of this article.

In the article, we answer these questions:

  • What are wearable medical devices?
  • In what ways are wearable medical devices CAD related?
  • Which wearable medical devices are in common use?
  • What trends are likely for the useof wearable medical devices?

What Are Wearable Medical Devices?

Wearable medical devices are biosensors which are attached to the body in order to monitor physiological data, usually with remote or wireless communication. Because these devices are wearable, they can provide 24/7 measured medical data to physicians to help them provide health care.

Examples:

  • A smart shirt is sometimes worn by athletes in order to measure heart rate and other vital physiological data which are analyzed and used for training.
  • A pulse oximeter is worn on a finger in order toreliably measure pulse rate and blood oxygen saturation.
  • A wearable blood pressure monitor is worn on an arm in order to measure blood pressure and heart rate.

In What Ways are Wearable Medical Devices CAD Related?

One role that CAD technology plays in creating wearable medical devices involves the use of Additive Manufacturing (or 3D printing) of wearable items.  For example, a Swedish company, Decomed Design, works with teams of CAD engineers, designers, IT professionals, and physicians to create a stylish 3D printed wearable medical device called an Akufeel bracelet.

This bracelet is an anti-nausea device which is worn on the wrist. The device provides pressure to an acupressure point on the inside of the wrist in order to relieve nausea symptoms which could arise due to pregnancy, the flu, motion sickness, side effects of medication, or other reasons.

Because of the stylish nature of the bracelet, the wearer is happy to add this adornment to his or her attire while enjoying an improved quality of life.

Additive Manufacturing is also used to create other wearable medical devices in the form of shoes, vests, hearing aids, implants, and prosthetics.

Which Wearable Medical Devices are in Common Use?

The majority of easy-to-design wearable medical devices measure activity and exercise such as calorie burn rate, heart rate, blood pressure, or distance walked. Wearable computers, smart watches, and smart clothing could provide such measurements.

Great interest has also arisen in building sophisticated wearable medical devices for monitoring complicated physiological functions such as brain activity, EKG, glucose levels, hydration, oxygen level, temperature, sleep, and other vital functions.

Although it is beyond the scope of this article to provide an exhaustive list of wearable medical devices, it is worthwhile to name a few of them.

  • Zephyr® manufactures a bio-data logger called Zephyr BioHarness which monitors posture, activity, breathing, and ECG. It can transmit data within a 10-meter range, and it is useful for Remote Patient Monitoring.
  • Medtronic® manufactures an FDA approved CGM (Continuous Glucose Monitor) and diabetes management system which includes an insulin pump.
  • Omron® manufactures an FDA approved pain relief device for the arm, lower back, and the leg or foot.

What Trends are Likely for the Use of Wearable Medical Devices?

  • A breakthrough wearable device could soon emerge for controlling diabetes, due to research work being performed at UC San Diego’s Center for Wearable Sensors. Researchers are developing wearable medical devices which work by measuring chemical markers such as potassium or lactic acid levels present in sweat or saliva.
    Also, an improved wearable blood glucose level monitor may soon become available. This device non-invasively extracts interstitial fluid (which is just below the skin) to the surface without penetrating the skin, in order to measure blood-glucose levels.
  • Expect regulatory bodies such as the FDA to establish well-defined guidelines on the manufactureand use of wearable medical devices.Wearable medical devices have failure modes which could be caused by chemical reactions between the device and the skin, poor wireless communication, battery safety, or electric shocks. Asfailure mechanisms becomewell understood, reliable wearable medical devices will be manufactured with predictable and dependable lifetimes.

When data transmission protocols and device reliability become more robust, patient care will depend more heavily on the use of wearable medical devices. Consequently, the cost of health care will be reduced, and fewer patients will be confined to hospital beds.