FIELD OF THE INVENTION

The present invention generally relates to medical systems and in particular, to a medical system with multiple operating modes for steering a medical instrument through linked body passages.

BACKGROUND

One type of medical instrument that is steered through body passages is an endoscope. Endoscopes allow physicians to capture images of and diagnose problems with internal body organs by inserting the device either through a natural orifice or a surgeon created opening and guiding it to a target site within a patient. In some cases, it may also be used to perform medical procedures on the internal body organs. It may be steerable so that its distal tip is controllably oriented for navigation purposes. An image capturing device such as a stereoscopic or monoscopic camera may be provided at its distal tip so that images captured by the camera from that perspective may be viewed on a display screen by the surgeon. To perform various medical procedures at the target site, surgical tools, such as those used for cutting, grasping, cauterizing, etc., may extend out of the endoscope's distal tip.

Specialized endoscopes may be named for where they are generally intended to look. Examples include: cystoscopes for looking in the bladder, nephroscopes for looking in the kidney, bronchoscopes for looking in bronchi of the lung, laryngoscopes for looking in the larynx, otoscopes for looking in the ear, arthroscopes for looking at joints, laparoscopes for looking inside the abdomen, and gastrointestinal endoscopes. In order to look at their intended organs, endoscopes may move through linked body passages in the body to a target area.

Another type of medical instrument that is steerable through body passages is a catheter. Catheters are long slender flexible tubes that are inserted into a natural bodily cavity or passage for introducing or withdrawing fluid. Its uses include the drainage of urine from the bladder through the urethra or insertion through a blood vessel into the heart for diagnostic purposes. Catheters may also be inserted in a passage to keep the passage open.

Still other types of medical instruments that are steerable through body passages are surgical and diagnostic tools. Examples include such common medical implements as forceps for taking tissue samples and electrodes used for cauterization of tissue.

Body passages through which such medical instruments are steered may be circuitous and have varying widths along their lengths. Further, they may be multi-branched and narrow so that navigation to target areas in the body is difficult. Also, the passage may comprise sensitive tissue that is easily harmed by excessive physical contact with the medical instrument. As an example of linked body passages, U.S. Pat. No. 7,901,348 B2 describes visual-assisted guidance of an ultra-thin flexible endoscope to a predetermined region of interest within the bronchial tree of a lung during a bronchoscopy procedure. As other examples of linked body passages, U.S. 2005/0182319 A1 describes image guided surgery techniques applicable to the blood circulatory system as well as the air circulatory system of the lung, the digestive system, and the urinary system.

When an operator is inserting a medical instrument through linked body passages to a target area in an anatomical structure of a patient, it may be desirable to assist the operator in navigating the medical instrument to the target area. In retracting the medical instrument back out of the linked body passages, care must be taken to avoid harming the passage walls by excessive physical contact with the medical instrument. Safety for the patient is a primary concern at all times while controlling movement of the medical instrument in the patient.

OBJECTS AND SUMMARY

Accordingly, one object of one or more aspects of the present invention is a medical system, and method implemented therein, for controlling the movement of a medical instrument through body passages without causing harm to a patient.

Another object of one or more aspects of the present invention is a medical system, and method implemented therein, for providing navigation assistance when useful to an operator for steering a medical instrument to and/or from a target area through linked body passages in a safe and efficient manner.

Still another object of one or more aspects of the present invention is a medical system, and method implemented therein, for providing automatic navigation assistance with manual override to a target area through linked body passages.

These and additional objects are accomplished by the various aspects of the present invention, wherein briefly stated, one aspect is a medical system comprising: a steerable medical instrument; at least one actuator; and control means for commanding the at least one actuator to cause the medical instrument to be steered according to an insertion control mode after movement of the medical instrument is detected in an insertion direction and commanding the at least one actuator to allow the medical instrument to move in compliance with forces exerted against the medical instrument after movement of the medical instrument is detected in a retraction direction.

Another aspect is a method for controlling the steering of a medical instrument, the method comprising: detecting movement of the medical instrument; and commanding at least one actuator to cause the medical instrument to be steered according to an insertion control mode after movement of the medical instrument is detected in an insertion direction and commanding the at least one actuator to allow the medical instrument to move in compliance with forces exerted against the medical instrument after movement of the medical instrument is detected in a retraction direction.

Another aspect is a medical system comprising: an input device; a medical instrument; at least one actuator; and control means for commanding the at least one actuator to cause the medical instrument to be steered according to a programmed navigation path in a normal control mode and for commanding the at least one actuator to cause the medical instrument to be steered according to movement of the input device commanding such steering when the normal control mode is manually overridden by an operator of the input device.

Yet another aspect is a method for controlling the steering of a medical instrument, the method comprising: commanding at least one actuator to steer the medical instrument according to a programmed navigation path while being moved in an insertion direction; receiving a manual override indication; and commanding the at least one actuator to steer the medical instrument according to movement of an input device.

Additional objects, features and advantages of the various aspects of the present invention will become apparent from the following description of its embodiments which description should be taken in conjunction with the accompanying drawings.

