Fluid injection device

A fluid injection device comprising:

• a pulse generation section that includes:
• a fluid chamber, which is a space enclosed by a sealing surface, an inner peripheral wall, and a diaphragm, the fluid chamber is substantially formed as a rotating body and a volume of the fluid chamber changes by extending and shrinking through the diaphragm;
• a swirl flow generation section generating swirl flow of fluid around an axis of the fluid chamber, the swirl flow generation section being formed on an exterior of the fluid chamber, and the swirl flow generation section being connected to the inner peripheral wall of the fluid chamber in a substantially tangential direction;
• and
• an outlet flow passage connected to the fluid chamber and formed at a portion which is closer to an axis of the rotating body or at the axis of the rotating body;
• a first connection flow passage connected to the outlet flow passage, having an end portion;
• a second connection flow passage connected to the swirl flow generation section;
• a fluid injection opening formed at the end portion of the first connection flow passage, having a diameter smaller than a diameter of the outlet flow passage, the fluid injection device being a surgical device and the fluid injection opening injecting fluid outside of the surgical device for dissecting or cutting out biopsy tissues;
• a connection flow passage tube including the first connection flow passage and having rigidity adequate to transmit pulses of fluid flowing from the fluid chamber to the fluid injection opening;
• a pressure generation section that supplies fluid to the swirl flow generation section;
• and
• a reinforcing plate that has an opening whose diameter is substantially equal to a diameter of the fluid chamber, and that is formed between the sealing surface on which the swirl flow generation section is formed or a swirl flow generation plate and the diaphragm, wherein the diaphragm and the reinforcing plate are stacked and attached in intimate contact with each other as an integral body.