Implantable medical devices management

Medical Device Batteries describes wearable and implantable medical devices powered by batteries. Devices include those that are used for cardiac rhythm management (pacemakers, defibrillators, and heart failure devices), hearing loss, bone growth and fusirm, drug delivery for therapy or pain relief, nerve stimulation for pain management, urinary incompetence and nervous system disorders, vision, diagnostic measurements and monitoring, and mechanical heart pumps. 

Some implantable medical devices use secondary cells as a way to minimize the number of device replacement surgeries compared to primary cells. An example is neurostimulation for pain management for which primary cells have almost been supplanted entirely by rechargeable cells. The result is longer device longevity in a small size. 

Management approaches have therefore emphasized the need for prevention through the addition of good sterile technique at the time of insertion. Manufacturers have also responded by using materials and creating surface characteristics of implanted materials inclement to microbial attachment. Likewise the use of prophylactic antibiotics at the time of insertion of deep-seated devices such as joint and heart valve prostheses has further reduced the risk of infection. Once a medical device becomes infected, management is difficult. Treatment with agents such as flucloxacillin, vancomycin and most recently linezolid is often unsuccessful and the only course of action is to remove the device. 

In this entry are discussed a few of the specialized batteries for medical devices that are portable or wearable (carried with the patient, like hearing aids), or implantable (surgically placed inside the body as with neurostimulation pain management devices). There is a focus on the batteries designed for a few of the more common applications - implantable cardiac rhythm management (cardiac pacemakers and defibrillators), pain management, and hearing loss devices. 

Li-ion cells used for consumer electronics are designed for 500 100% DOD cycles with 80% retained capacity. In 1998, the company Quallion was founded to develop a Li-ion chemistry with long life, low calendar fade and Zero-Volt characteristics for medical device implants. Since traditional Li-ion chemistries experience a shortened life when the cells voltage are below 1.5-2 V, a Zero-Volt Li-ion cell is especially enabling to pain management devices, where a patient may not routinely recharge the device. 

Based on the shortcomings with respect to safety management revealed by recent medical device failures, involving heart valves, pacemakers, and breast implants, we would recommend that the following be undertaken ... 

Inclusion of the implantation and follow-up phases of the product life cycle in the risk control process. This would require safety management systems, which are in general not yet available in the medical device industry and health care. 

Bristow, M.R., A.M. Feldman, and L.A. Saxon, Heart failure management using implantable devices for ventricular resynchronization Comparison of Medical Therapy, Pacing, and Defihrillation in Chronic Heart Failure (COMPANION) trial. COMPANION Steering Committee and COMPANION Clinical Investigators. J Card Fail, 2000. 6(3) p. 276-85. 

QuaUion, LLC [24] QL0003I, QL0020B, QL0200I-A (Batteries) Medical implants, sensors cochlear implants, spinal cord stimulators, glucose sensors, and cardiac rhythm management devices... 

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