Fluid jet device, drive device of fluid jet device, surgical instrument, and method of driving fluid jet device

Abstract

A fluid jet device including a fluid chamber with variable capacity and a capacity varying section adapted to vary the capacity of the fluid chamber in response to supply of a drive signal. A drive waveform section making the capacity varying section operate so as to compress the capacity of the fluid chamber and a restoring drive waveform section making the capacity varying section operate to restore the capacity of the fluid chamber before compressing the capacity in a signal waveform. The drive signal supply section controls supply content of the drive signal to provide a restoring period adapted to restore a steady state of the fluid flowing toward an inside of the fluid chamber in a period from when the compressing drive waveform section in the drive signal is supplied to when a subsequent compressing drive waveform section is supplied.

1 . (canceled) 
     
     
         2 . A surgical instrument comprising:
 a fluid chamber with a variable capacity;   a capacity varying section configured to vary the capacity of the fluid chamber in response to the supply of a drive signal;   a nozzle configured to eject fluid supplied from the fluid chamber; and   a drive signal supply section configured to supply the capacity varying section with the drive signal, the driving signal including a compressing drive waveform section, causing the capacity varying section to compress the capacity of the fluid chamber, and a restoring drive waveform section, causing the capacity varying section to restore the capacity of the fluid chamber before compressing the capacity in a signal waveform of one cycle,   wherein the drive signal supplied by the drive signal supply section to the capacity varying section also includes a constant waveform section between the compressing drive waveform section and the restoring drive waveform section, the constant waveform section forming a constant signal level.   
     
     
         3 . The surgical instrument according to  claim 2 , wherein the drive signal supplied by the drive signal supply section to the capacity varying section has the signal waveform of one cycle configured by combining a part of a sine wave that forms the compressing drive waveform section and whose one-cycle time length is T1, and a part of a sine wave that forms the restoring drive waveform section and whose one-cycle time length is T2, where T1<T2. 
     
     
         4 . The surgical instrument according to  claim 3 , wherein the time length of T2 is equal to or more than five times of the time length of T1. 
     
     
         5 . The surgical instrument according to  claim 4 , wherein the signal level of the constant waveform section is equal to the maximum level of a signal level of the compressing drive waveform section. 
     
     
         6 . The surgical instrument according to  claim 2 , wherein the signal level of the constant waveform section is equal to the maximum level of a signal level of the compressing drive waveform section. 
     
     
         7 . The surgical instrument according to  claim 5 , wherein the signal level of the constant waveform section is equal to the maximum level of the signal level of the restoring drive waveform section. 
     
     
         8 . The surgical instrument according to  claim 6 , wherein the signal level of the constant waveform section is equal to the maximum level of the signal level of the restoring drive waveform section. 
     
     
         9 . The surgical instrument according to  claim 2 , wherein the signal waveform of the one cycle is in the shape of a trapezoidal wave. 
     
     
         10 . The surgical instrument according to  claim 2 , wherein the drive signal supply section varies the time length of the constant waveform section in response to the variation of a fluid jet emission intensity 
     
     
         11 . The surgical instrument according to  claim 2 , wherein the capacity varying section includes:
 a diaphragm configured to seal an end of the fluid chamber, and   a piezoelectric element connected to the diaphragm, wherein the piezoelectric element performs one of expanding and shrinking in a direction perpendicular to a seal surface in response to the supply of the drive signal, and   wherein the drive signal supply section causes the expansion of the piezoelectric element to deform the diaphragm toward an inside of the fluid chamber by supplying the compressing drive waveform section in the drive signal, and causes the shrinking of the piezoelectric element to restore the diaphragm in a deformed state to the diaphragm in a state prior to the deformation in the deformed state by supplying the restoring drive waveform section in the drive signal.