Apparatus for rapid cooling of the brain and method of performing same
Rather than cooling the brain by the relatively slow heat conduction through the low heat conductivity of the bony skull and hair covering the head, the present invention teaches the use of a light weight, easily applied neck encircling collar in firm contact with the soft tissue of the neck, and particularly in good thermal contact with the carotid arteries traversing the neck. A coolant flowing through channels embedded in the collar rapidly cools the blood flowing through the carotid arteries which branch into blood vessels throughout the brain providing vascular access and attendant rapid internal cooling throughout the brain including its deepest recesses. Placing the collar on the patient's neck is easily and quickly accomplished simultaneously with other emergency medical techniques, such as CPR, which maintain the patient's heart and lung activity. The collar of the invention contains no metallic parts; the collar, including the coolant channel, may be non-metallized fabric or plastic. This allows X-ray, Cat scan, or MRI procedures to be used while the collar is in place without impairing the effectiveness of the procedure. In a second embodiment, a conventional endotracheal tube, inserted into the trachea is provided with an toroidal bladder surrounding the tube. The toroidal bladder is positioned at the back of the oral cavity, and a coolant flowing through the toroid cools blood vessels in the oral cavity which traverse the brain, providing cooling of the brain tissue.
This application claims the benefit of U.S. Provisional Application No. 60/030,030 filed Nov. 4, 1996.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates to apparatus and method for cooling the brain, and in particular to apparatus and method for inducing hypothermia throughout the tissues of the brain.
2. Description Relative to the Prior Art
It is well known in the medical art that depriving the brain of oxygen for even a short period of time results in irreversible damage to the brain tissue. Such deprivation occurs during stroke, respiratory arrest, cardiac arrest, trauma and other severe bodily disturbances that slow or otherwise hinder the flow of oxygenated blood to the brain. However, it is also known that lowering the temperature of the brain (hypothermia) slows its metabolic activity, and reduces the chance of tissue damage when the oxygen supply is diminished.
At present, operative neurosurgery and cardiac surgery is done in many cases using hypothermia for the specific purposes of maintaining cerebral and cardiac function. In an operating room, this requires use of a cooling module in conjunction with heart/lung bypass techniques by which the patient's blood, and resultantly the patient's brain tissue, is cooled. This widespread ability to rapidly lower brain temperature by as little as four or five degrees can make an enormous difference in preservation of function. However, out in the field, when medical emergencies occur, brain cooling must quickly and expeditiously take place without access to the sophisticated equipment available in the hospital operating room. A portable brain cooling apparatus usable in the field is described in U.S. Pat. No. 5,261,399, issued in the names of Klatz et al. For use on an injured or disabled patient, the patent discloses a helmet and back plate containing cavities in which a coolant flows to cool the brain by means of heat conduction through the skull and upper spinal column.
SUMMARY OF THE INVENTIONRather than cooling the brain by the relatively slow heat conduction through the low heat conductivity of the bony skull and hair covering the head, the present invention teaches the use of a light weight, easily applied neck encircling collar in firm contact with the soft tissue of the neck, and particularly in good thermal contact with the carotid arteries traversing the neck. A coolant flowing through channels embedded in the collar rapidly cools the blood flowing through the carotid arteries which branch into blood vessels throughout the brain providing vascular access and attendant rapid internal cooling throughout the brain including its deepest recesses. Placing the collar on the patient's neck is easily and quickly accomplished simultaneously with other emergency medical techniques, such as CPR, which maintain the patient's heart and lung activity.
The collar of the invention contains no metallic parts; the collar, including the coolant channel, may be non-metallized fabric or plastic. This allows X-ray, Cat scan, or MRI procedures to be used while the collar is in place without impairing the effectiveness of the procedure.
In a second embodiment for rapid internal cooling of the brain, a conventional endotracheal tube, inserted into the trachea, is provided with an toroidal bladder surrounding the tube. The toroidal bladder is positioned at the back of the oral cavity, and a coolant flowing through the toroid cools blood vessels in the oral cavity which also traverse the brain, providing cooling of the brain tissue.
The endotracheal tube and the bladder are made from materials including non-metallic fabric or plastic materials, such that these components are compatible with X-ray, MRI or CAT scan procedures.
The coolant flowing through the channels of the collar or the toroidal bladder may be any of the well known liquid or gaseous refrigerants, for example, gaseous CO2, freon, or ice water, pumped through the channels of the collar or toroidal bladder in a manner known in the refrigeration art.
The invention will be described with respect to the drawings, of which:
Referring to
Referring to
In
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention. For example, the first embodiment of the invention may be incorporated into a neck support collar used for supporting an injured patient's head.
Claims
1. Apparatus for inducing hypothermia in a patient's brain, said apparatus comprising:
- a) an endotracheal tube having a first end and second end,
- b) a toroidal shaped bladder surrounding said tube proximate said first end of said tube, said first end for insertion into said a patient's trachea whereby said bladder contacts the tissues and blood vessels of said a patient's oral cavity,
- c) a source of liquid or gaseous coolant, said source for providing coolant to said bladder,
- d) inlet and outlet coolant conducting elements connected to said toroidal shaped bladder, whereby said coolant from said source flowing through said inlet and outlet coolant conducting elements cools said bladder, further whereby when said first end of said endotracheal tube is inserted into said a patient's trachea, said coolant flowing in said bladder lowers the temperature of said the tissues and blood vessels of said a patient's oral cavity in contact with said bladder, said the tissues and blood vessels further acting as heat conducting paths from said a patient's brain to said bladder whereby the temperature of said the brain is lowered.
2. The apparatus of claim 1 wherein said endotracheal tube and said bladder comprises non-metallic fabric or plastic materials, whereby said apparatus is compatible with X-ray, MRI or CAT scan procedures.
3. The apparatus of claim 1 further comprising refrigeration means supplying said coolant.
4. A method of inducing hypothermia in a patient's brain comprising the step of:
- a) cooling said brain by lowering the temperature of the blood flowing in blood vessels located in said patient's oral cavity,
- b) inserting an endotracheal tube into contact with said patient's trachea, said endotracheal tube having a toroidal bladder surrounding said endotracheal tube, said bladder being in contact with blood vessels located at the rear of said patient's oral cavity,
- c) flowing coolant through said bladder by means of an inlet tube to said bladder and an outlet tube from said bladder, whereby said blood vessels are lowered in temperature to cool said brain.
5. The method of claim 4 further comprising the steps of:
- a) inserting an endotracheal tube into contact with said patient's trachea, said endotracheal tube having a toroidal bladder surrounding said endotracheal tube, said bladder being in contact with blood vessels located at the rear of said patient's oral cavity and
- b) flowing coolant through said bladder by means of an inlet tube to said bladder and an outlet tube from said bladder, whereby said blood vessels are lowered in temperature to cool said brain.
6. A method of inducing hypothermia in a patient's brain, comprising the steps of:
- a) inserting a coolant contact comprising a bladder, an inlet coolant conducting tube and an outlet coolant conducting tube into the oral cavity of the patient, the bladder being in contact with tissues proximate blood vessels located at the rear of the patient's oral cavity; and
- b) flowing coolant through the bladder by means of the inlet coolant conducting tube and the outlet coolant conducting tube, whereby the tissues and blood vessels are lowered in temperature to cool the brain.
7. The method of claim 6 wherein the bladder is a toroidal bladder and the coolant contact further comprises an endotracheal tube, wherein the toroidal bladder surrounds the endotracheal tube.
3976065 | August 24, 1976 | Durkan |
4423725 | January 3, 1984 | Baran et al. |
4552149 | November 12, 1985 | Tatsuki |
5261399 | November 16, 1993 | Klatz et al. |
5314456 | May 24, 1994 | Cohen |
5480417 | January 2, 1996 | Hascoet et al. |
6149624 | November 21, 2000 | McShane |
6321121 | November 20, 2001 | Zelickson et al. |
6325818 | December 4, 2001 | Werneth |
WO 91/05528 | May 1991 | WO |
- Critical Care Medicine, 1996, vol. 24, No. 6, pp. 911-914.
Type: Grant
Filed: Jun 27, 2001
Date of Patent: May 22, 2007
Inventor: George R. Schwartz (Santa Fe, NM)
Primary Examiner: Lee S. Cohen
Attorney: Peacock Myers, P.C.
Application Number: 09/895,623
International Classification: A61F 7/12 (20060101);