System and Method for Improved Start-Up of Self-Oscillating Electro-Mechanical Surgical Devices

• US 20110241786A1
• Filed: 03/30/2010
• Published: 10/06/2011
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Tyco Healthcare Group LP (Medtronic Plc)
• Inventors: Gilbert, James A.
• Granted Patent: US 8,258,886 B2
• Time in Patent Office: Days
• US Class Current: 331/34
• CPC Class Codes: A61B 17/320092 with additional movable means for clamping or cutting tissue, e.g. with a pivoting jaw
• CPC Class Codes: A61B 2017/00017 Electrical control of surgical instruments
• CPC Class Codes: A61B 2017/0015 applied simultaneously
• CPC Class Codes: A61B 2017/320093 additional movable means performing cutting operation
• CPC Class Codes: A61B 2017/320095 with sealing or cauterizing means

Abstract

An oscillating circuit for determining a resonant frequency of an electro-mechanical oscillating device and for driving the electro-mechanical oscillating device at the determined resonant frequency includes a driving circuit and a start-up, impetus injection circuit. The driving circuit is configured to receive one or more reference signals and further configured to provide a driving signal related to the reference signals to the electro-mechanical oscillating device. The start-up, impetus injection circuit is operably coupled to the electro-mechanical oscillating device and configured to selectively provide a start-up excitation signal to the electro-mechanical oscillation device. The start-up, impetus injection circuit is activated upon start-up of the oscillating circuit to drive the electro-mechanical oscillation device and the driving circuit determines a resonant frequency by measuring a parameter related to the resonant frequency of the electro-mechanical oscillating device.

Claims

1. An oscillating circuit for determining a resonant frequency of an electro-mechanical oscillating device and for driving the electro-mechanical oscillating device at the determined resonant frequency, the oscillating circuit comprising:

a driving circuit configured to receive at least one reference signal and further configured to provide a driving signal related to the at least one reference signal to the electro-mechanical oscillating device; and

a start-up, impetus injection circuit operably coupled to the electro-mechanical oscillating device, wherein the start-up, impetus injection circuit is configured to selectively provide a start-up excitation signal to the electro-mechanical oscillation device, and wherein the start-up, impetus injection circuit is activated upon start-up of the oscillating circuit to drive the electro-mechanical oscillation device,

wherein the driving circuit determines a resonant frequency by measuring a parameter related to the resonant frequency of the electro-mechanical oscillating device.

2. The oscillating circuit of claim 1, wherein the driving circuit determines a resonant frequency of the electro-mechanical oscillating device within one-half cycle of the resonant frequency.

3. The oscillating circuit of claim 1, wherein the driving circuit determines a resonant frequency of the electro-mechanical oscillating device within three cycles of the resonant frequency.

4. The oscillating circuit of claim 1, wherein the parameter related to the resonant frequency and related to motion of the electro-mechanical oscillating device.

5. The oscillating circuit of claim 4, wherein the parameter related to the resonant frequency is selected from a group consisting of current, voltage and mechanical position.

6. The oscillating circuit of claim 1, wherein the oscillating circuit further includes:

an excitation signal generating circuit, and

a start-up switch configured to selectively couple the excitation signal generating circuit to the electro-mechanical oscillating device.

7. The oscillating circuit of claim 6, wherein the excitation signal generating circuit further includes:

a DC voltage source; and

an energy storage device operatively coupled to the DC voltage source in a first condition and operatively coupled to the start-up switch in a second condition,

wherein in the first condition, the DC voltage source charges the energy storage device, and, in the second condition, the energy storage device drives the electro-mechanical oscillating device to a position related to a point of maximum amplitude.

8. The oscillating circuit of claim 7, wherein the energy storage device includes a capacitor.

9. The oscillating circuit of claim 6, where the excitation signal generating circuit further includes:

an digital-to-analog signal converter configured to generate a time-frequency varying driving signal operatively coupled to the start-up switch,

wherein the electro-mechanical oscillating device is driven by the time-frequency varying driving signal generated by the digital-to-analog signal converter.

10. The oscillating circuit of claim 9, wherein the frequency of the time-frequency varying driving signal varies linearly with respect to time.

11. The oscillating circuit of claim 9, wherein the frequency of the time-frequency varying driving signal varies exponentially with respect to time.

12. The oscillating circuit of claim 6, wherein the excitation signal generating circuit further includes:

a narrowband, pseudo-random noise generator circuit configured to generate the excitation signal within a resonant bandwidth.

13. The oscillating circuit of claim 12, wherein the narrowband, pseudo-random noise generator circuit further includes a bandpass filter.

14. The oscillating circuit of claim 12, wherein the bandpass filter includes an analog circuit.

15. The oscillating circuit of claim 12, wherein the pseudo-random noise generator is a digital excitation sequence predetermined to be within the bandwidth of resonance of the electro-mechanical oscillator.

16. A method for starting an electro-mechanical oscillating device, the electro-mechanical oscillating device having a varying resonant frequency, the method comprising the steps of:

generating a start-up excitation signal;

applying the start-up excitation signal to an electro-mechanical oscillating device;

driving the electro-mechanical oscillating device to a position related to a point of maximum amplitude;

removing the excitation signal from the electro-mechanical oscillating device when the electro-mechanical oscillating device is at a position related to the point of maximum amplitude;

measuring at least one parameter related to a resonant frequency of the electro-mechanical oscillating device;

determining a resonant frequency of the electro-mechanical oscillating device; and

driving the electro-mechanical oscillating device at the determined resonant frequency.

17. The method of claim 16, wherein the at least one parameter is selected from the group consisting of current, voltage and mechanical position.

18. A method for starting an electro-mechanical oscillating device, the electro-mechanical oscillating device having a varying resonant frequency, the method comprising the steps of:

generating a time-frequency varying start-up excitation signal;

applying the time-frequency varying start-up excitation signal to an electro-mechanical oscillating device;

measuring at least one parameter related to a resonant frequency of the electro-mechanical oscillating device while driving the electro-mechanical oscillating device with the time-frequency varying excitation signal;

determining the resonant frequency of the electro-mechanical oscillating device; and

driving the electro-mechanical oscillating device at the determined resonant frequency.

19. The method of claim 18, wherein the at least one parameter is selected from the group consisting of current, voltage and mechanical position.

20. A method for starting an electro-mechanical oscillating device, the electro-mechanical oscillating device having a varying resonate frequency, the method comprising the steps of:

generating a start-up excitation signal from a pseudo-random noise sequence signal within the resonant bandwidth;

driving the electro-mechanical oscillating device with the start-up excitation signal;

measuring at least one parameter related to a resonant frequency of the electro-mechanical oscillating device;

determining the resonant frequency of the electro-mechanical oscillating device; and

driving the electro-mechanical oscillating device at the determined resonant frequency.

21. The method of claim 20, wherein the at least one parameter is selected from the group consisting of current, voltage and mechanical position.