MEANS AND METHOD FOR PICTORIAL PRESENTATION OF PHYSIOLOGICAL SIGNALS WHICH VARY WITH TIME AND POSITION

• US 3,707,147 A
• Filed: 08/13/1970
• Issued: 12/26/1972
• Est. Priority Date: 08/13/1970
• Status: Expired due to Term

• Current Assignee: Ernest E. Sellers
• Original Assignee: Ernest E. Sellers
• Inventors: Sellers, Ernest E.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/063,394
• Time in Patent Office: 866 Days
• Field of Search: 128/2A,2R,2V,2.5Q,2.5R,2.6G,2.6R,2.6V,2.6B,2.1B,2.1R
• US Class Current: 600/525
• CPC Class Codes: A61B 5/303 Patient cord assembly, e.g. cable harness
• CPC Class Codes: A61B 5/339 Displays specially adapted therefor
• CPC Class Codes: G01R 13/245 for generating more than one, not overlapping time-intervals on the screen

Abstract

A method and apparatus are disclosed for recording and displaying in a single picture the value of a signal, such as an electrocardial voltage, which varies as a function of time and position on a body. The display may be formed on an oscilloscope and is like a television picture in that an entire area is filled with information and each point in the area and the overall pattern are meaningful. The display shows signal value as a function of time along one axis and shows signal value as a function of position along another axis. The beam of the cathode ray tube is deflected through multiple sweeps along one axis while deflecting it through a single sweep along the other axis with traces which effectively fill the area bounded by the axes. The deflection along the respective axes are correlated with time and position on the body and the beam is continuously modulated in accordance with the amplitude of the signal. Preferably, the beam is deflected with multiple traces along the position axis and the signal is measured at discrete positions. The value of the signal at intermediate positions is derived by interpolation and the modulation is preferably accomplished by intensity modulation of the beam to achieve various shades of grayness.

Claims

1. The method of making a two-dimensional display of the value of a variable quantity which is continuously varying with time and position on a body comprising the steps of establishing a first axis on a recording medium with displacement therealong from the origin corresponding to time, establishing a second axis on the recording medium with displacement therealong from the origin corresponding to position, moving a recording element through multiple sweeps along one of Said axes of the recording medium while moving it through a single sweep along the other of said axes, producing during said multiple sweeps multiple traces of sufficient intensity to be continuously visible on the medium each of which is effectively contiguous with the adjacent trace, said traces thereby occupying substantially all of the area bounded by said axes on said recording medium, the motion of the recording element along one of said axes being a function of time and the motion along the other of said axes being a function of position on said body, and continuously modulating a recording characteristic of said recording element in accordance with the continuously varying value of the variable quantity whereby said area has a continuously modulated quality and every point therein represents a value of said quantity at a given time and position.

2. The invention as defined in claim 1 wherein the motion along the first axis is a function of position on said body and the motion along the second axis is a function of time and wherein said recording characteristic is light intensity.

3. The method of making a two-dimensional display representing the variation of the value of a continuously varying variable quantity which is variable with time and position on a body comprising the steps of:

producing a continuously varying signal corresponding to the value of the variable quantity at different positions during equal time intervals, establishing a first axis on a recording medium with displacement therealong from the origin corresponding to time, establishing a second axis on the recording medium with displacement therealong from the origin corresponding to position, displacing a recording element along one of said axes of the recording medium as a function of time so that the maximum displacement corresponds to said time interval, displacing the recording element along the other of said axes in correspondence with the sequence of selection of positions on said body, generating a trace of multiple sweeps along one of said axes during a single sweep along the other of said axes, continuously recording the trace of said recording element during its forward scan along one of said axes and continuously modulating in a continuously variable manner a recording characteristic of said recording element in accordance with the continuously varying value of said signal, said trace being of sufficient intensity to be continuously visible on the medium with the multiple sweeps thereof being effectively contiguous with the adjacent sweep so that the trace occupies substantially all of the area bounded by said axes on said recording medium, whereby said area has a continuously modulated quality and the value of the variable quantity for any position is displayed as a substantially continuously variable function of time along one axis and the value of the variable quantity at a given time is displayed as a function of position along the other axis in a single picture.

4. The invention as defined in claim 3 wherein said recording characteristic of said recording element is the intensity of the trace thereof.

5. The invention as defined in claim 4 wherein said recording element is displaced through multiple sweeps along said first axis during the single sweep of said element along said second axis and wherein said step of continuously recording the trace of said recording element is performed during the forward scan along said first axis thereby producing multiple, continuous, side-by-side lines each of which represents the continuous variation in the value of the variable quantity with time for different positions on said body.

6. The invention as defined in claim 3 including the step of producing signals corresponding to interpolated values of the variable quantity at positions intermediate said different positions and wherein said step of modulating is performed in accordance with the value of said signals including those corresponding to the interpolated values of the variable qUantity.

7. Apparatus for making a two-dimensional display representing the time variation of the value of a variable quantity at different positions on a body comprising:

signal producing means for producing signals in time succession corresponding to the values of the variable quantity at different positions during equal time intervals, a signal to light transducer having an image forming means with light producing means adapted to produce a spot of light movable along first and second axes thereof and forming a persistent trace thereon, one of said axes being calibrated in terms of time and the other being calibrated in terms of position, first deflection means connected with the light producing means for displacing said spot of light along a first axis as a function of time so that the maximum displacement corresponds to said time intervals, second deflection means connected with the light producing means for displacing said spot of light along a second axis in correspondence with said different positions, one of said deflection means producing multiple parallel sweeps of the light spot along the respective axis during a single sweep of the light spot along the other axis, means in said transducer producing a continuous spot of light and trace which is continuously visible during its said multiple parallel sweeps in the forward direction thereof, and said signal producing means being connected with the signal to light transducer and continuously modulating a characteristic of said light spot in a continuously variable manner in accordance with the value of the variable quantity.

8. The invention as defined in claim 7 wherein said variable quantity is an electrical voltage at selected positions on a human body incident to the heartbeat of said body and wherein said equal time intervals correspond to one or more cycles of said heartbeat, and said signal producing means includes plural electrodes disposed at selected positions on said body and means for sequentially connecting said electrodes with said light producing means.

9. The invention as defined in claim 8 further including modulating means connected with said signal producing means and said light producing means, said modulating means being adapted to modulate the intensity of said spot of light in accordance with the value of the variable quantity.

10. The invention as defined in claim 8 and further including modulating means connected with said signal producing means and one of said deflection means and adapted to produce a minor deflection of said spot of light in accordance with the value of the variable quantity.

11. The invention as defined in claim 7 wherein said one of said deflection means is said first deflection means thereby producing multiple continuous traces corresponding to different positions on said body, each of said traces representing the variation in time of said variable quantity at a corresponding position.

12. The invention as defined in claim 11 and further including a constant frequency oscillator connected with said second deflection means, the frequency of said oscillator being high relative to the sweep frequency along said first axis thereby effectively widening said continuous traces.

13. The invention as defined in claim 7 wherein said one of said deflection means is said second deflection means thereby producing a multiplicity of continuous parallel traces, each of which represents the value of the variable quantity at a given time at the various positions.

14. The invention as defined in claim 13 and further including interpolation means connected with said signal producing means and said signal-to-light transducer and adapted to modulate said continuous trace in accordance with interpolated values of said variable quantity at positions intermediate said different positions.

15. The invention as defined in claim 7 and further including means for exposing a light sensitive film to the signal-to-light transducer during one full cycle of the signals produced in timE succession.

16. The invention as defined in claim 7 and further including signal recording means connected with said signal producing means to record the signals electrically, whereby said signals may be played back and applied to said signal-to-light transducer for delayed viewing of said display.

17. The invention as defined in claim 8 wherein said signal-to-light transducer is a cathode ray tube.