Method and apparatus for determining the condition of a biological specimen

• US 4,203,035 A
• Filed: 07/25/1977
• Issued: 05/13/1980
• Est. Priority Date: 01/14/1976
• Status: Expired due to Term

• Current Assignee: Picker International, Inc. (Marconi Holdings Company Limited)
• Original Assignee: Baird Corporation
• Inventors: Grenier, Raymond P.
• Primary Examiner(s): Dixon, Harold A.
• Application Number:
  US05/818,735
• Time in Patent Office: 1,023 Days
• Field of Search: 250/367, 250/363 S, 250/366, 250/461 B
• US Class Current: 250/363.02
• CPC Class Codes: G01T 1/1647 Processing of scintigraphic data not related to a particular imaging system G01T1/2992

Abstract

A computer controlled high resolution radiaoactivity distribution detection system is provided for sensing radioactive events in a biological specimen. The system includes a rotating disc memory which contains instructional data for controlling the computer. Radiation emitted from a subject positioned on programmable XY platform is directed through a collimator and is detected by means of an array of sensing devices and front end electronics. The detected radioactive events are temporarily held in a buffer memory under control of the computer for storage. The temporarily stored data is fed via the computer to a disc memory for long term storage, a disc controller constitutes an interface to the disc memory. The stored data is then applied to a display via computer for presentation.

Claims

1. A method for determining the condition of a selected organ in a biological specimen containing a diagnostic amount of radioactive sample, said method comprising the steps of:

(a) sensing radioactive events that are emitted from the sample within the specimen, said events sensed by a multi-crystal array having a plurality of unique address locations;

(b) temporarily storing and accumulating the sensed events in a buffer memory;

(c) applying signals defining said accumulated sensed events in said buffer memory to a disc memory;

(d) transferring said signals in said disc memory between said disc memory and a general purpose computer;

(e) generating raw data signals of said sensed events, said raw data signal defining a first raw data curve;

(f) generating a smooth data curve corresponding to said raw data curve;

(g) generating data points defining the maximum positive and negative slopes of the smooth data curve by determining the first derivative of a primary curve of the maximum number of detected events;

(h) generating a second raw data curve by linear extrapolation of the rising side of a primary curve of said first data curve from data points about said data point defining the maximum positive slope to a base line of said first raw data curve and by exponential extrapolation of the falling said of said primary curve of said first data curve from data points about said data point defining the maximum negative slope to said base line of said first raw data curve; and

(i) generating data signals defining the condition of the biological specimen by reduction of the biological specimen by reduction of said second raw data curve to find the centroid of said second raw data curve which is the mean transit time or volume divided by flow in the selected organ undergoing diagnosis; and

(j) applying said data signals to a display for presentation of indica defining the condition of said biological specimen, said method utilizing a sampling rate in the order of 0.05 second.