Hydraulic systems for applications in laparoscopic surgical tools, as well as tools for other surgical procedures, are known. Current laparoscopic surgical instruments typically have considerable limitations, however, including difficulties in accessing portions of the body obstructed by organs or other objects, difficulties in sterilizing all or portions of such tools, and difficulties in ease of use. Further, while such existing laparoscopic surgical instruments can perform invasive surgical procedures, the instruments are often awkward to manipulate and have problems performing complicated movements often necessary in surgery. In particular, such instruments can be difficult to manipulate around corners, obstacles and to use in obstructed or otherwise difficult to reach environments.
In addition, existing laparoscopic surgical instruments may either have a fairly limited range of motion and/or are not capable of performing certain sophisticated and delicate operations or motions with precision. Further, such instruments may also be fairly limited in their flexibility to accommodate unexpected or unanticipated motion. Also, existing laparoscopic surgical instruments often lack an intuitive connection between motion initiated by the user in the control portion of the device and corresponding motion actuated remotely in the slave portion of the device.
Moreover, existing laparoscopic surgical instruments typically use cables and hydraulic lines to manipulate the surgical tip of the instruments. The hydraulics often require the use of special hydraulic fluid that is not necessarily amenable to surgical environments or other special environments. For example, the use of conventional hydraulic oils in surgical environments is ill-advised and may create an assortment of hazards, especially if the system leaks or the hydraulic conduits are prone to rupture. While more medically compatible hydraulic fluid may be used (e.g., water, mineral oils, etc.), such fluid tends to evaporate at a significant rate. Monitoring and replenishing such fluid manually can be costly and labor intensive. Further, the consequences of not being vigilant concerning fluid levels could be severe, particularly in a surgical environment.
In addition, the tools used by the device can be expensive and difficult to clean and sterilize. Since the cleaning and sterilization procedure must be performed after each use, any expense incurred can substantially add to the cost of use of the device. Alternatively, if disposable tools are used, the need for their continual replacement can add to the cost of the overall system. Also, disposable tools may be made from less robust materials as those meant for multiple uses, leading to increased potential for problems due to equipment malfunction and/or fracture.
Moreover, laparoscopic surgical instruments using cables and hydraulic lines to remotely manipulate the surgical tip of the instruments can be vulnerable to accidental misuse or user overcompensation sometimes due to a lack of direct tactile feedback. This danger is especially significant when the apparatus is not in deliberate use (e.g., when the device is dormant during a critical portion of surgery where other equipment is being used), is being serviced/stored or is not being operated by a skilled practitioner. Inadvertent and potentially damaging maneuvers are possible, for example, when the device is moved in between operating theaters or when routine maintenance is being performed. In particular, problems can arise when a user moves a control for a laparoscopic surgical device in such a way that can cause damage either to the device itself, to ancillary devices and/or to the patient.