Electrocardiographic recording method and apparatus

A method of controlling a D.C. drive motor and the supplying of digital data to the chart of a recorder to produce a constant time scale chart record regardless of temporary variations in the preselected nominal D.C. drive motor speed comprising:

• storing sensed digital data by means of a buffer memory;
• controlling the speed of the D.C. drive motor in accordance with the amount of data stored in the buffer memory, so that the motor speed is increased if the buffer memory is storing more than a preselected amount of data, and so that motor speed is decreased if the buffer memory is storing less than the preselected amount of data;
• and
• outputting sensed data from the buffer memory and supplying such data to the chart at a rate proportional to the speed of the D.C. drive motor, so as to produce a constant time scale chart record of such data regardless of temporary variations in the D.C. drive motor speed.

A method of controlling a D.C. drive motor and digital printhead of an electrocardiogram to produce a chart record at a constant time scale regardless of temporary variations in the preselected nominal D.C. drive motor speed comprising:

• storing sensed digital ECG data;
• controlling the speed of the D.C. drive motor in accordance with the amount of the ECG data stored, so that the motor speed is increased if the amount of data stored is more than a preselected amount of data, and so that motor speed is decreased if the amount of data stored is less than the preselected amount of data;
• and
• outputting ECG data to the printhead for recording at a rate proportional to the speed of the D.C. drive motor, so as to produce a constant time scale chart record of such data regardless of temporary variations in the D.C. drive motor speed.

Apparatus employing a D.C. drive motor and digital printhead for recording electrocardiographic data on a chart at a constant time scale, regardless of temporary variations in the preselected nominal D.C. drive motor speed, comprising:

• buffer memory means for storing sensed digital ECG data, including a preselected amount of data;
• means for controlling the speed of the D.C. drive motor in accordance with the amount of data stored in said buffer memory means, so that the motor speed is increased if the buffer memory means is storing more than said preselected amount of data, and so that motor speed is decreased if the buffer memory means is storing less than said preselected amount of data;
• and
• means for outputting ECG data from the buffer memory means to the digital printhead for recording at a rate proportional to the speed of the D.C. drive motor, so as to produce a constant time scale chart record of said data regardless of temporary variations in the D.C. drive motor speed.

Apparatus employing a D.C. drive motor and means for supplying digital data for recording on a chart at a constant time scale, regardless of temporary variations in the preselected nominal D.C. drive motor speed, comprising:

• buffer memory means for storing the digital data, including a preselected amount of data;
• means for controlling the speed of the D.C. drive motor in accordance with the amount of data stored in said buffer memory means, so that the motor speed is increased if the buffer memory means is storing more than said preselected amount of data, and so that motor speed is decreased if the buffer memory means is storing less than said preselected amount of data;
• and
• means for outputting data from the buffer memory means to the means for supplying digital data for recording at a rate proportional to the speed of the D.C. drive motor, so as to produce a constant time scale chart record of said data regardless of temporary variations in the D.C. drive motor speed