Life-sustaining device

Premarket Approval applies to life-supporting or life-sustaining devices. Class III devices are those that support or sustain human life, are of substantial importance in preventing impairment of human health, or which present a potential, unreasonable risk of illness or injury. Those devices that if used improperly may cause unreasonable risk or illness or injury to a person. These devices must meet the standards set forth in Class I and Class II in addition to premarket approval of Class III. Examples include heart pacemakers, replacement heart valves, implanted spinal cord stimulators, silicone gel-filled breast implants. 

Life sustaining devices provide therapy that keeps a patient alive. An implantable defibrillator is an example of a life sustaining device. Certain cardiac patients experience tachycardia (a very rapid heart beat) or ventricular fibrillation. Either condition limits the ability of the heart to effectively pump blood. Death can result if this type of arrhythmia is sustained and a normal heart rhythm is not restored by a defibrillator. 

The FDA has divided devices into three classes to identify the level of regulatory control applicable to them. The highest category, Class III, includes those devices for which premarket approval is or will be required to determine the safety and effectiveness of the device (21 CFR, 860.3(c) 21 U.S.C., 360c(a)(l)(C)). Absent a written statement of reasons to the contrary, the FDA classifies any implant or life-supporting or life-sustaining device as Class III (21 CFR, 860.93 21 U.S.C., 360c(c)(2)(C)). 

Class I devices are considered low-risk devices and represent approximately 50% of all devices regulated by the FDA. A device is assigned to Class I if general controls are sufficient to provide reasonable assurance as to the safety and effectiveness of the device. Devices that are not life-supporting or life-sustaining, or are for a use which is... 

Medical devices are classified and regulated according to their degree of risk to the public. Devices that are life-supporting, life-sustaining, or implanted, such as pacemakers, must receive agency approval before they can be marketed. 

The layer upon layer of fractal redundancy in scale-free biological systems suggests that attack at one level does not place the organism at undue risk. But attack at vital transmission nodes can cause catastrophic failure of the system. The development of multiple organ dysfunction syndrome (MODS) in critically ill humans may be such a failure. Once devolved, death almost inevitably ensues. The similarity to concerted attack on vital Internet router nodes is evident. Patients managed by conventional non-fractal life support may sustain further unintentional attack on a devolving scale-free system due to loss of normal fractal transmission. Returning fractal transmission to life support devices may improve patient care and potentially offer benefit to the sickest of patients. 

Steps taken to limit unauthorized device access to trusted users only, particularly for those devices that function in life-sustaining or could directly connect to networks. 

There are several ways to classify medical devices. Some provide therapeutic functions while others are used for diagnostic purposes. Some provide both functions. For therapeutic devices, devices may be further described as life sustaining or life enhancing (improves the quality of life). 

Class III, Premarket Approved—a device for which insufficient information exists to assure that general controls and performance standards would provide reasonable assurance of safety and effectiveness. This device is life sustaining, life supporting, or may be implanted in the body, and represents a potentially unreasonable risk of illness or injury. Devices in this category are required to have approved applications for premarket approval. 

LiCF batteries offer high energy and power densities, sustained performance over an ultra-wide temperature range (from -60° to 160°C), and long service or shelf life. These devices are best suited for portable electronics, military search and rescue communications, transportation, RFID, and medical defibrillators. 

Although current dialysis therapy is life-sustaining, its simple physical transport processes cannot replace the complex transport, metabolic, and endocrine functions of the tubular cells. A bioartificial kidney that includes a conventional dialysis filter and a renal tubule assist device (RenaMed Biologies, formerly Nephros Therapeutics) containing approximately 10 renal proximal tubule cells was recently successfiiUy engineered (Tiranathanagul et al., 2005 Humes et al., 1999). In the renal tubule device, cells are... 

The life span of a batteiy is also dependent on the power needs of a product. Some batteries produce a lot of power for a relatively short time before fully discharging, while others are designed to provide less peak power but more sustained power for a very low drain rate. Other important variables aftccting batteiy lifespan are the design and efficiency of the device being used and the conditions of use. In particular, exposing a batteiy to excessive heat can dramatically curtail the length of a battery s life. 

The device is intended to be used outside a user facility to support or sustain life. 

More recently, the challenge to formulate with consistency highly potent actives present in diminishingly low concentrations raised the bar for formulations another significant notch. Procedures and devices for safe intravitreal implantation of sustained antiviral medication have grown from the advent of new therapies for a life- and eye-threatening new disease, HIV-AIDS. 

For persons with type 1 diabetes, insulin replacement therapy is necessary to sustain life. Pharmacologic insulin is administered by injection into the subcutaneous tissue using a manual injection device or an insulin pump that continuously infuses insulin under the skin. Interruption of the insulin replacement therapy can be life-threatening and can result in diabetic ketoacidosis or death. Diabetic ketoacidosis is caused by insufficient or absent insulin and results from excess release of fatty acids and subsequent formation of toxic levels of ketoacids. 

Chemical fuel, however, is not the only means by which energy can be supplied to operate molecular-level devices. As recalled in the previous section, nature shows that in green plants the energy needed to sustain the machinery of life is supplied by sunlight. Photochemical energy inputs can indeed cause the occurrence of endergonic chemical reactions, which can make a device work without formation of waste products. Currently there is an increasing interest in... 

Class III—Premarket Approval Devices that support or sustain life or present a significant risk of illness or injury fall under the Class-Ill category. Implants, such as pacemakers and silicone gel breast implants, are Class-Ill products, as are internal tissue adhesives, thermal ablation devices, synthetic ligaments and tendons, vacumn pumps, and prosthetic hips. Class-Ill accounts for about 10% of aU medical devices. 

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