Methods and apparatus for quantifying tissue damage, determining tissue type, monitoring neural activity, and determining hematocrit
First Claim
1. A method for quantifying cellular damage in a tissue sample, comprising:
- measuring average sodium ion concentration in the entire tissue sample ([Na]t);
measuring average potassium ion concentration in the entire tissue sample ([K]t);
obtaining a value equal to [Na]t -[K]t ; and
comparing said value to the value of [Na]t -[K]t in normal tissue,whereby the degree of deviation from normal values is a quantitative indication of cellular damage.
1 Assignment
0 Petitions
Accused Products
Abstract
Tissue damage may be quantified, tissue type identified, neural activity monitored or blood hematocrit determined by measuring the difference between the total tissue sodium and potassium concentrations in the area in question. Comparison of these measurements with standard values permit evaluation of the amount of tissue damage in cells of the same type or the tissue type in non-necrotic cells. Evaluation over time of normal brain cells permit monitoring of neural activity. By directly and simultaneously measuring sodium and potassium ion concentrations, for example, a nuclear magnetic resonance spectrometer can image areas of different tissue type in differing colors. In this manner tumors and lesions can be clearly delineated. Measurement of total potassium concentration of a blood sample and the potassium concentration of the cell-free plasma will permit determination of cellular volume fraction (hematocrit).
35 Citations
36 Claims
-
1. A method for quantifying cellular damage in a tissue sample, comprising:
-
measuring average sodium ion concentration in the entire tissue sample ([Na]t); measuring average potassium ion concentration in the entire tissue sample ([K]t); obtaining a value equal to [Na]t -[K]t ; and comparing said value to the value of [Na]t -[K]t in normal tissue, whereby the degree of deviation from normal values is a quantitative indication of cellular damage. - View Dependent Claims (2, 3, 4, 5, 6, 8, 9, 10, 11)
-
-
7. A method for determination of kind of tissue, comprising:
-
measuring sodium ion concentration in the total tissue sample ([Na]t); measuring potassium ion concentration in the total tissue sample ([K]t); obtaining a value equal to [Na]t -[K]t ; and comparing said value to the value of [Na]t -[K]t in tissue of known type, whereby obtaining a value equal to that of tissue of known kind is an indication that the tissue sample comprises tissue of that known kind.
-
-
12. A method for monitoring neural activity in an undamaged portion of brain tissue, comprising:
-
measuring average a sodium ion concentration in the portion of brain tissue being studied ([Na]t) at predetermined intervals of time; measuring average potassium ion concentration in the portion of brain tissue being studied ([K]t) at the same predetermined intervals of time; obtaining a value equal to [Na]t -[K]t at each said time interval; and comparing said values obtained over time, whereby variation of said values over time is an indication of neural activity in the brain tissue being studied. - View Dependent Claims (13, 14)
-
-
15. A method for determining the volume fraction of cells in a tissue sample, comprising:
-
measuring potassium ion concentration or total potassium weight present in the tissue sample ([K]t); measuring or assuming extracellular potassium ion concentration ([K]e); and using a predetermined value for the ionic gradient across cell membranes (G) in the tissue sample, calculating cell volume fraction (Vi /Vt), using the formula Vi /Vt =([K]e -[K]t)/G. - View Dependent Claims (16)
-
-
17. An apparatus for determining and displaying a value representative of the amount of cellular damage in a tissue sample or the tissue type of a non-necrotic tissue sample, comprising:
-
first measuring means for measuring the total tissue sodium ion concentration in the tissue sample; second measuring means for measuring the total tissue potassium ion concentration in the tissue sample; processor means for subtracting the measured value of potassium ion concentration obtained from said second measuring means, from the measured value of sodium ion concentration obtained from said first measuring means, to obtain a value for the calculated difference; and display means for displaying the calculated difference obtained by said processor means. - View Dependent Claims (18, 19, 20, 21, 22)
-
-
23. An apparatus for determining the volume fraction of cells in a tissue sample, comprising:
-
potassium measurement means for determining the total potassium content or potassium ion concentration of a tissue or fluid sample; calculator means connected to said potassium measurement means, for calculating cellular volume fraction from the values obtained by said potassium measurement means; and output means connected to said calculator means, for outputting the calculated values of cellular volume fraction. - View Dependent Claims (24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35)
-
-
36. A method for measuring the average Na and K gradient across cellular membranes (G) in tissues that have been removed from the body, comprising:
-
measuring or estimating the cell volume fraction (Vi /Vt) of the tissue sample; measuring the potassium ion concentration in the tissue sample ([K]t); measuring the sodium ion concentration in the tissue sample ([Na]t); measuring or assuming a value of extracellular potassium ion concentration ([K]e); measuring or assuming a value of extracellular sodium ion concentration ([Na]e); and calculating G using the formula;
space="preserve" listing-type="equation">G=(([Na].sub.t -[K].sub.t)-([Na].sub.e -[K].sub.e))/2·
(V.sub.i /V.sub.t).
-
Specification