Single scan microprocessor-controlled densitometer

Abstract

A microprocessor-controlled densitometer system for optically scanning a blood sample or the like and generating an electric analog signal which is a function of the optical density of the scanned sample. The electrical analog signal is processed and converted into digital data for storage in a memory as raw sample data to be retained until the next given sample is scanned. Under microprocessor control, a CRT device displays a re-constructed optical density analog waveform pattern representative of the generated electrical analog signal and may be normalized for full-scale readings. While the optical density analog waveform pattern is displayed on the CRT device, the operator may visually inspect and edit the analog waveform pattern by manually positioning a cursor signal along the CRT displayed analog waveform pattern for addressing selected positions thereon and modify the analog waveform pattern by keyboard entries which add, delete, or modify fraction boundary locations, delete portions of the analog waveform pattern from computations, etc., via keyboard entries and under microprocessor control. Once the operator is satisfied with the edited analog waveform pattern and the various fraction boundaries displayed on the CRT device, a keyboard command to the microprocessor enables the displayed and edited optical density waveform pattern or any integral or selected portion thereof to be graphically recorded as an analog profile trace on a fixed record medium and may, under microprocessor control, cause a printer to print fraction identifying information and numerical data such as ratios or percentages involving the area under the analog waveform pattern or particular fractions thereof, amplitude ratios, or scaled values calculated by the microprocessor onto the record medium and preferably in a position proximate to the fraction or portion of the profile traced to which such data pertains. The method and apparatus of the present system enables the displaying and editing of the analog waveform pattern, the calculation of desired numerical data, the recording of the profile trace and the printing of the calculated data without requiring that the sample be scanned a second time and without disturbing the digital data stored in the memory which represents the originally generated electrical analog waveform since the reconstruction of the display, the editing, and the numerical calculations are done under microprocessor control using only stored data and operator-entered keyboard commands.