Methods to shorten calibration times for powered devices
A calibration method for a hand-held surgical instrument is disclosed. The hand-held instrument includes a drive motor, a firing rod controlled by the drive motor and having at least one indicator, and a sensor configured to detect the at least one indicator. A microcontroller includes a pulse modulation algorithm stored therein to control the drive motor. The microcontroller executes a calibration algorithm to adjust at least one program coefficient in the pulse modulation algorithm.
1. A method for calibrating a hand-held surgical instrument having a drive motor, a firing rod, a sensor, a microcontroller, and a memory having a pulse modulation algorithm stored therein, the method comprising:
initiating translation of the firing rod;
detecting at least one indicator on the firing rod;
determining a time between when translation of the firing rod is initiated and when the at least one indicator is detected;
comparing the time with a predetermined time; and
adjusting at least one program coefficient in the pulse modulation algorithm based on the comparison between the time and the predetermined time.
2. The method of claim 1 , further comprising:
determining a linear speed of the firing rod; and
selecting the predetermined time based on the determined linear speed of the firing rod.
3. The method of claim 2 , wherein if the time is less than the predetermined time, the at least one program coefficient is adjusted so that the firing rod is translated a relatively shorter distance.
4. The method of claim 2 , wherein if the time is greater than the predetermined time, the at least one program coefficient is adjusted so that the firing rod is translated a relatively longer distance.
5. A hand-held surgical instrument comprising:
a drive motor;
a firing rod controlled by the drive motor and having at least one indicator;
a sensor configured to detect the at least one indicator; and
a microcontroller having a pulse modulation algorithm stored therein, the pulse modulation algorithm being configured to control the drive motor; and
a position calculator configured to determine a time between when the firing rod begins translation and when the sensor detects the at least one indicator,
wherein the microcontroller executes a calibration algorithm to adjust at least one program coefficient in the pulse modulation algorithm.
6. The hand-held surgical instrument of claim 5 , wherein the indicator is a bump, groove, indentation, magnet, notch, or at least one thread on the firing rod.
7. The hand-held surgical instrument of claim 5 , wherein the sensor is a linear displacement sensor.
8. The hand-held surgical instrument of claim 5 , wherein the microcontroller receives the time from the position calculator and compares the time to a predetermined time.
9. The hand-held surgical instrument of claim 8 , wherein the microcontroller adjusts the at least one program coefficient based on the comparison between the time and the predetermined time.
10. The hand-held surgical instrument of claim 9 , wherein the sensor determines a linear speed of the firing rod.
11. The hand-held surgical instrument of claim 10 , wherein the microcontroller selects the predetermined time based on the linear speed of the firing rod.