In this blog, I want to highlight a seemingly impossible design problem that Cactus Semiconductor took on with an electronic solution that will save and improve countless lives.
Many people need to take prescription drugs to improve their blood pressure, lower their cholesterol, and many other reasons to improve their health. Some seemingly non-life critical conditions appear not to be a serious threat if we miss a dose or two; however, many people (especially the elderly) forget to take a dose of maybe take a double dose because they forgot that they already swallowed that pill an hour ago---that could lead to a serious overdose condition or if the behavior is chronic, your kidneys could fail or you could have a heart attack.
Andrew Kelly, Cactus Semiconductor IC/Systems architect behind the podium and to his left is Jonathan Withrington, IC Design Manager, Proteus Digital Health (Image courtesy of Loretta Taranovich)
At the semi.org MEMS & Sensors Executive Congress in San Jose recently, Andrew Kelly elaborated upon the following facts regarding medical adherence from American Heart Association (AHA) statistics:
- There are 187 Americans requiring Prescriptions
- 20% to 30% of Medication Prescriptions are never filled
- 50% of all Medications are not taken as prescribed
- 30% to 50% of treatment failures are due to non-adherence
- 125,000 annual deaths are due to non-adherence
The Proteus Discover device
The Proteus Discover system contains ingestible sensors, a small wearable sensor patch, an application on a mobile device and a provider portal.
Shown here is a summary from Proteus that reveals a chronic problem of a patient not taking their pills on time, skipping doses or doubling up on doses. (Image courtesy of Proteus)
The system is FDA-cleared, monitors and tracks taking of medication (Precise Medication, Dosage, Timing, & Frequency Data), provides medication-taking data to prescribers, and improves engagement with the patient's Healthcare Team.
The pill sensor design challenges
- First, how do to generate power when designers cannot use a traditional battery because of the size and toxicity of standard batteries?
- Next, implementing Passive/Wireless Charging, which needs a prohibitive inductor size and low signal strength.
- The device will be swallowed and then enter into a human stomach, so the solution needs to be non-toxic as well as non-harmful
- Signal Propagation inside a human stomach will be have a high attenuation and variability
- The product swallowed will need programmability with an individual serial number for each pill and in addition, every pill must be accurately and reliably recognized
- Accurate data integrity is critical
- The system needs to be manufacturable and support high production volumes
- Continuity of supply must be maintained with capability of long-term production
- The cost needs be insignificant as compared to the medication
- Functionality and performance improvements in future design revisions as well as no size increase in the future
Other than these problems---the design should be easy!