Surgery – Miscellaneous – Methods
Reexamination Certificate
1998-03-24
2002-05-21
Yu, Mickey (Department: 3738)
Surgery
Miscellaneous
Methods
Reexamination Certificate
active
06390097
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates, in general, to a method and system for planning surgical paths and associating risks with planned surgical paths. In particular, the present invention relates to a method and system for planning surgical paths and associating risks with planned surgical paths, wherein the surgical paths are those paths leading to a neurological tumor, such as a brain tumor.
2. Description of Related Art
Anatomically, the brain consists of three main structures: the central brain stem, the cerebrum, and the cerebellum. Each such structure contains within it many other defined regions and/or substructures associated with specific brain function(s).
The brain stem is divided into substructures. Such substructures include the thalamus, hypothalamus, and medulla oblongata. The thalamus is the relay station for incoming sensory signals and outgoing motor signals passing to and from the brain stem and cerebrum. The hypothalamus regulates or is involved directly in the control of eating, drinking, temperature regulation, sleep, emotional behavior, sexual activity, and visceral functions. The medulla oblongata regulates and controls cardiac, vasoconstrictor, and respiratory functions, as well as other reflex activities, including vomiting.
The cerebrum is the largest part of the human brain and is divided into several substructures. These substructures include, among others, the right and left cerebral hemispheres, each of which is divided by fissures and gyri (convolutions) into five lobes: the frontal, parietal, temporal, occipital, and insula lobes.
Many distinct brain functions have been associated with different regions and substructures within the cerebrum. These regions and substructures include the following. The somatomotor area, located just in front of what is known as the central fissure of one cerebral hemisphere, is responsible for nearly all voluntary movement of body muscles. The somatosensory area, which is responsible for touch and taste, which is located just behind what is known as the central fissure of one cerebral hemisphere. The region of the cortex responsible for hearing is located in the upper, or superior, convolution of the temporal lobe of one cerebral hemisphere. The visual cortex, the region responsible for seeing, is located in the occipital lobe of one cerebral hemisphere. The olfactory area, the region responsible for smell, is located in the front, internal portion of the temporal lobe. Broca's area responsible for the muscle movements of the throat and mouth used in speaking, is located just beneath the motor area. The understanding of speech and reading has been associated with areas between the auditory and visual areas. The frontal area of the human cortex is responsible for awareness, intelligence, and memory.
The cerebellum is essential to the control of movement of the human body in space. It acts as a reflex center for the coordination and precise maintenance of equilibrium. Voluntary muscle tone—as related to posture, balance, and equilibrium—is similarly controlled by the cerebellum. All motor activity depends on the cerebellum.
The foregoing identified functional areas are just a fraction of those areas of the brain with which a specific function has been associated. Eloquence can be defined to be the quality of forceful or persuasive expressiveness. Consequently, areas of the brain identified with the expression of functions will be referred to herein as eloquent areas. Damage to “eloquent” areas of the brain typically results in severe impairment or elimination of the function(s) associated with such damaged eloquent area (e.g., severe damage to the medulla oblongata structure usually results in immediate death).
A brain tumor is an abnormal growth, swelling, or enlargement in the brain. There are many types of brain tumors such as those arising from the brain itself (e.g., astrocytoma, glioblastoma, oligodendroglioma, ependymoma), those arising from the brains coverings, or meninges, (e.g., meningiomas, pituitary tumors, pineal tumors), or those arising from nerves at the base of the brain (e.g., acoustic neuromas, schwannomas), and even tumors arising from outside the brain (metastatic brain tumors). This last case occurs when cancer cells travel through the bloodstream and lodge in the brain.
Brain tumors can be malignant or benign. A malignant tumor is one that is actively destroying surrounding brain cells. A benign tumor is a mass or swelling that is growing, but is not destroying the surrounding brain cells. While a benign tumor in other organs is not ordinarily cause for alarm, a benign brain tumor is cause for alarm.
The brain is encased in the cranium. The cranium is a dome-like vault of bone and cartilage that is essentially unyielding. Surrounding the brain is cerebrospinal fluid under a pressure, which supports the brain and protects it from injury. Cerebrospinal fluid is essentially incompressible, and thus the introduction of a tumor, even a benign one, into the cranial vault will require compression of the structures which can be compressed: the cells of the brain. Such compression ultimately will result in brain injury, and thus even benign tumors must be removed as quickly as possible. Thus, even a benign tumor can cause severe damage and must be removed quickly and in its entirety. Thus, irrespective of whether a brain tumor is malignant or benign, an active course of treatment must be engaged in to remove the tumor.
Unfortunately, this is easier proposed than done, for brain tumors are significantly different from other types of tumors, and hence are uniquely difficult to remove. There are several reasons for this, but perhaps the most significant is that brain tumors are in/on the brain, and thus reaching and removing the tumor with surgical instruments gives rise to the risk that eloquent brain areas will be damaged in either the process of reaching the tumor or removing it. A second reason is that brain tumors aren't like ordinary tumors: brain tumors are polyclonal, which means that what appears to be one tumor is actually many (sometimes over a thousand) tumor clones colocated in one area. Consequently, true tumor margins do not exist and consequently total removal by local therapy (surgery, radiation, heat, cold, etc.) is not possible. A third reason is that the brain is separated from the blood-stream by the blood-brain barrier, and consequently many blood-born chemotherapeutic agents cannot reach the brain via the blood-stream. A fourth reason is that many brain tumor cells live in a low oxygen (hypoxic) environment, and it has been found empirically that these hypoxic cells are: (1) radio-resistant; (2) often chemotherapy resistant; and (3) far from the blood supply. Thus, brain tumors prove to be exceedingly difficult to treat as compared with other tumors, as the following simple example will make clear.
Imagine that a particular tumor weighs about 100 grams. Consider the following: 100 gm of tumor typically has approximately 100 billion cells. Because a typical tumor can double in size and volume in a matter of weeks, from a course of treatment standpoint it makes sense to decrease the size of the mass of the tumor right away. Surgery is the preferred way of radically reducing the volume of a tumor, removing anywhere from 80 to 90% of the tumor mass. Recent advances in surgical technologies have aided in the removal of brain tumor tissue with a newer, higher net percentage tumor reduction of 90-99%. These include computer assisted stereotactic surgery, laser instrumentation (carbon dioxide, argon, and Yag), ultrasonic aspiration, operative phototherapy, focused beam radiotherapy proton beam radiation—the Gamma knife, linear accelerator—the “X-knife,” brachytherapy—radiation seeds implanted into the tumor bed, cryotherapy, thermal therapy, ultrasonic therapy, phototherapy, drug and immunotherapies injected locally into the tumor bed via an Omaya reservoir, intraarterial therapy—selective exposure of involved brain via angiography
Bracewell & Patterson L.L.P.
International Business Machines - Corporation
Nguyen Dinh X.
Salys Casimer K.
Yu Mickey
LandOfFree
Method and system for providing artificial intelligence for... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and system for providing artificial intelligence for..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and system for providing artificial intelligence for... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2876421