In a recent article about trends in the embedded medical market, I pointed out that there are opportunities at every end of the embedded processing spectrum. I would like to take the opportunity to explore the embedded medical market in further detail than just a single trend piece, and I would like to encourage you to send me information so I can cover it or you can submit a contributed article for our voices of industry section and get the byline credit for yourself. To start things off for this series, I will highlight new or upcoming medical devices.
One large area for opportunities is in the home continuous monitoring space. Miniaturization continues to make a mark in this area as recording devices become smaller and less intrusive. The shrinking sizes of these devices provide an added benefit because patients are able to wear them more comfortably and they are less intrusive in pursuing everyday living. This provides a mechanism that increases the patient compliance for monitoring and improves the quality of the data that doctors can collect about their patient because they can see the patient’s vital statistics at the time they are experiencing whatever symptoms they cannot repeat in an office visit.
The iRhythmZio event card and patch are examples of how home monitoring devices are shrinking in size. Only a few years, my daughter wore a 24 hour recorder that was the size of a portable cassette tape player. The Zio Event Card weighs less than 2 ounces and looks like a thick credit card with a cord attached to it. It is not a continuous recording device, but it can record and store up to two ECG (Electrocardiography) sessions when patient indicates they have a symptom. It is a single-use, disposable device that lasts for up to 30 days. The user interface consists of electrode pads, a button, audio tones, and a green/orange flashing light. When the patient wishes to record an event, they press the button on the card. To download the data on the card to the doctor, the patient calls the company’s clinical center, and they are walked through the process to send the data.
The Zio patch differs from the event card because it is worn directly on the patient’s skin and provides continuous monitoring for up to 7 to 14 days. Patches pose a different set of challenges than a credit card recorder because patches are worn on the patient’s skin rather than worn on a belt, or on a necklace or lanyard. The credit card form factor is rigid and that provides protection to the components inside the card. A patch cannot be as rigid as a card; it has to support some flexibility so as to be able to move with the patient’s body – otherwise there is a risk that the patient will remove the patch. A patch- or bandage-based device should also take care not to have sharp edges or points within the device otherwise they could cut or puncture the patient’s skin. Also, because the patch device is mounted on the patient’s skin, there is a need to make sure the patch does not become too warm as to become uncomfortable.
The credit card, patch, and bandage are poised to be common form factors for emerging home medical devices. These types of devices represent some of the most exciting embedded applications – especially when you consider that they must operate with users that might not want to use them.