"Each of these implantable devices delivers a therapeutic output to the patient. In the case of an implantable therapeutic substance infusion device, the therapeutic output can be a therapeutic substance which is infused into the patient. In the case of a neurological tissue stimulator, the therapeutic output is an electrical signal intended to produce a therapeutic result in the patient. Other types of implantable therapeutic delivery devices also exist including cardiac pacemakers and defibrillators.
"Electrically powered implanted therapeutic delivery devices can require replacement once implanted due to factors such as battery consumption, corrosive damage and mechanical wear. Since replacement of the implanted therapeutic delivery device requires an invasive procedure of explanting the existing device and implanting a new device, it is desirable to only replace the therapeutic delivery device when replacement is required. Replacement of previously implanted therapeutic delivery devices was typically scheduled based upon a worst-case statically forecasted elective replacement period. The worst-case scenario typically resulted in the implanted therapeutic delivery device being replaced several months or even years before the implanted therapeutic delivery device actually required replacement.
"Some previous implantable pulse generators such as pacemakers have monitored a single sensed battery condition to estimate replacement time for the implanted device or battery such as shown in U.S. Pat. No. 6,167,309, Lyden, entitled 'Method For Monitoring End Of Life For Battery' (
"Battery monitors which monitor the voltage of the battery in order to determine, or to predict, the remaining longevity of the battery have an inherent shortcoming. The voltage of a battery will commonly very slowly decline over time with only a slight variation in the voltage until the voltage the battery nears the end of its useful life. As the battery nears the end of its useful life, the battery voltage will begin to decline at a greater rate, often dramatically. Such a battery is advantageous as a source of power for an implantable therapeutic delivery device because the battery delivers such an assured relatively constant voltage over most of the useful life of the device. However, such a battery creates a problem for a battery longevity monitor using the voltage of the battery in an attempt to determine the longevity of the battery. Since the battery voltage remains relatively constant over most of the life of the battery, it is difficult to predict whether the battery is in the early part of the relatively flat voltage curve or nearing the end of the relatively flat voltage curve. The difference, of course, is a marked difference in the predicted longevity of the battery.
"The ability to accurately predict the remaining longevity of the power source of an implantable therapeutic delivery device enables the patient to receive maximum life from the device and minimize the frequency, and possibly the number, of explantation and reimplantation of the device simply for the replacement of the power source. Further, since some safety margin is usually built in and because the patient usually schedules any such explantation and reimplantation, often around a busy schedule, additional time off of the actual remaining longevity of the power source may be lost.
"For the foregoing reasons, there is a need for an implantable therapeutic delivery device with active longevity prediction to increase the implantable therapeutic delivery device's effective life, reduce the need for a clinician to perform static longevity forecasts for therapy changes, facilitate elective replacement scheduling for the convenience of the patient and clinician, and many other improvements."
Most Popular Stories
- Bipartisan Budget Deal Gets Key Support in House
- Bitcoin Clones Lurch Onto Financial Scene
- Clinton to Keynote Annual Simmons Leadership Conference
- TFA Recruiting DACA Recipients
- Scotch Whisky Sales Raise Distillers' Spirits
- Holiday Shopping Off to a Slow Start This Season
- Fake Deaf Interpreter Was Hallucinating, Has Schizophrenia
- Tea Party Glum in Face of Bipartisan Budget Deal
- Budget Deal Will Cut 220,000 Californians Out of Jobless Benefits
- Health Coverage Disparities Emerge Among States