A goniometric robotic arrangement

Abstract: In a robotic arrangement an elongate telescope(10) is provided adapted to be inserted into a patient(6). A drive arm(8) is connected to the telescope and means(7) are provided to rotate the drive arm about a substantially vertical axis. Drive means are provided associated with the drive arm(8) to adjust the angle of inclination of the cannula. This may comprise means to adjust the angle of inclination of the drive arm(8) itself.

Description: THE PRESENT INVENTION relates to a goniometric robotic arrangement and more particularly relates to a goniometric robotic arrangement intended for use in a medical environment. EP-A-0571827 discloses a goniometric robotic arrangement which incorporates a telescope adapted to be inserted into a patient through an incision. The described arrangement includes a support which supports a horizontal beam so that a terminal portion of the beam can be located above the patient. The support incorporates a drive mechanism to effect upward and downward movement of the beam. The beam itself supports a drive arm by means which are adapted to rotate the drive arm about a substantially vertical axis which, in use of the arrangement, is coincident with an incision in the patient through which the telescope is inserted into the patient. According to this invention there is provided a goniometric robotic arrangement incorporating a telescope adapted to be inserted into a patient through an incision in the abdomen of the patient, the arrangement comprising a support arrangement supporting a support beam so that a terminal portion of the support beam can be located above the patient, the support arrangement incorporating a drive mechanism to effect upward and downward movement of the support beam, the support beam supporting a drive arm by means adapted to rotate the drive arm about a substantially vertical axis which, in use of the arrangement, is coincident with the incision in the abdomen of the patient, there being a loose articulation connecting the free end of the drive arm to part of the telescope, wherein drive means are provided to adjust the angle of inclination of the drive arm relative to the horizontal, there being control means to synchronise the upward and downward movement of the support arrangement supporting the support beam and the change of angle of inclination of the drive arm such that the movement of the lower end of the telescope which, in use, is passed through the said incision in the patient, is goniometric, there being two light sources generated intersecting beams of light, the intersecting beams of light being adjusted to intersect at a position a predetermined distance beneath the upper end of the drive arm to define the point of incision of the patient. Preferably the means adapted to adjust the angle of inclination of the drive arm comprise a crown wheel-and-pinion device. Conveniently the crown wheel-and-pinion device is driven by a low torque motor. Advantageously the means adapted to rotate the drive arm comprise a motor contained within a motor housing, a substantially vertical drive shaft driven by the motor being connected to one end of the drive arm. Conveniently the lower end of the telescope is optically cranked, and means are provided to rotate at least the lower end of the telescope relative to the axis of the telescope. In order that the invention may be more readily understood, and so that further features thereof may be appreciated, the invention will now be described, by way of example, with reference to the accompanying drawings in which FIGURE 1 is a perspective view of one embodiment of the invention, and FIGURE 2 is a side view of part of the embodiment of Figure 1. Referring initially to Figure 1, a goniometric robotic apparatus in accordance with the invention comprises a housing 1, which may be mounted on rollers or casters 2 for ease of movement. A vertical support column 3 extends upwardly from the housing and telescopically receives an elongate vertical support member 4. The elongate support member 4 may be driven upwardly and downwardly by an appropriate mechanism. The mechanism may comprise a hydraulic mechanism, but preferably comprises a low torque electric motor associated with a direct drive mechanism such as a re-circulating ball drive. The elongate support member 4 supports, at its upper end, a horizontally extending support beam 5. The horizontal support beam 5 extends laterally beyond the housing 1 so that a terminal portion of the support beam can be located above a patient 6. The beam 5 carries, at a position located directly above the patient, a motor housing 7. A drive arm 8 extends from beneath the motor housing 7, the free end of the drive arm 8 being connected by a loose articulation 9 to a central part of a telescope 10, comprising part of a laparoscope. The drive arm 8, as will be described in greater detail below, has one end on the vertical axis of the rotation of a drive shaft of a motor, and the other end offset, both horizontally and vertically, so the drive arm 8 is inclined to the vertical and to the horizontal. The telescope 10 is associated with a camera 11 provided at the upper end of the telescope. The lower end of the telescope 10 is inserted through an appropriate incision 12 into the abdomen of the patient 6. The incision 12, which forms the entry point into the patient, lies on a notional extension of the vertical axis of the drive shaft of the motor. The telescope may pass through a short cannula in the region of the incision 12, the cannula forming a gas-tight seal between the telescope and the patient. Typically the abdomen of the patient will be insufflated with a gas such as nitrogen or carbon dioxide, thus separating the individual organs within the abdomen of the patient. This permits some movement of the end of the telescope within the abdomen of the patient. The gas-tight seal provided at the incision by the cannula prevents unintentional deflation of the patient. The motor housing 7 contains motors, one of which is adapted to rotate the drive arm 8 about a vertical axis 13, this being the axis of the drive shaft driving the drive arm 8 at its upper end. The axis 13 is coincident with the incision 12. The loose connection 9 thus effects a circular motion as indicated by the dotted line 14, about the axis 13. The telescope thus describes the exterior of a conical surface. The point where the telescope 10 passes through the incision into the abdomen of the patient effectively comprises a goniometric point. Since the connection 9 is a loose connection, as the drive arm 8 is rotated, the telescope 10 associated with the camera 11 is rotated in such a way that no stress is placed on the entry point to the patient. It is to be appreciated that by rotating the drive arm 8 about the vertical axis 13 in the manner described, the lower end of the telescope, within the abdomen of the patient will execute a "pan" action. As can be seen more clearly from Figure 2, the motor housing 7 is provided with an arrangement, schematically illustrated at 15 which can alter the angle 16 between the drive arm 8 and the lower surface of the motor housing 7. The arrangement 15 may comprise a crown wheel-and-pinion-type arrangement, with a motor driving the pinion, and the crown wheel being connected to the drive arm 8. Consequently, it is possible for the angle of inclination of the drive arm 8 to be adjusted. The drive arm 8 is inclined relative to the vertical axis 13 and relative to the horizontal axis. The degree of inclination may be adjusted by the motor driving the pinion of the crown wheel-and-pinion arrangement. If the elongate support member 4 is moved upwardly, thus moving the horizontal support beam 5 upwardly, and if the angle 16 is increased at an appropriate rate, the telescope 10 will occupy the same angle of inclination, but the lower part of the telescope 10 will be inserted more deeply into the abdomen of the patient. Consequently a "zoom" effect is achieved. The loose coupling 9, and the alignment of the entry point or incision 12 on the axis of rotation of the drive arm 8 ensures that the movement is goniometric movement. It is also to be appreciated that if the elongate support member 4 is moved upwardly, thus lifting the horizontal support beam 5, and if the angle 16 between the drive arm 8 and the under-surface of the motor housing 7 is increased at a relatively fast rate, the telescope 10 may be tilted to have a more vertical orientation. Conversely, by a lowering of the support beam 5 and decreasing the angle 16, the telescope 10 may be tilted to have a less vertical orientation. Thus a "tilt" function can be achieved. Again, because of the loose connection 9 and the alignment of the incision 12 with the axis of rotation of the drive arm 8 the movement is a goniometric movement. With appropriate control a "zoom" and a "tilt" may be effected simultaneously. Both of these movements, when effected simultaneously, will be goniometric. It is to be appreciated that the pan, zoom and tilt function will be achieved by appropriate controls operated by a surgeon or other operative. Appropriate software within a control arrangement will synchronise the upward movement of the elongate element 4 and any change of the angle 16 to achieve the required zoom or tilt effect. The three motors referred to above, namely the motor that drives the support member 4, the motor which rotates the drive arm 8, and the motor that drives the crown wheel of the crown wheel-and-pinion arrangement 15 are all low torque motors, preferably being direct drive motors with a sufficiently low gearing to permit back driving. If it is desired, for example in an emergency, to move the telescope 10 by hand, this can be done in an easy manner. Alternatively, fluid clutches, or some other form of "slippery" clutch could be incorporated in the drive mechanism to provide the same effect. As can be seen from Figure 2, the horizontal support beam 5 is provided with two spaced apart lights 20,21, the lights emitting sharply defined light beams 22,23 which are inclined inwardly towards one another. The beams intersect at a point on the axis 13. The arrangement is such that when the beam 5 is a predetermined distance above the abdomen of a patient, a position which may be termed an "initialising" position, the two light beams intersect each other on the skin of the patient. It is thus possible to move the horizontal support beam to a predetermined position relative to the skin of the patient, the two light beams each illuminating the part of the skin of the patient that will be where the incision 12 is located. This initial "initialising" of the apparatus is linked to controlling software to cause appropriate combinations of vertical motions of support member 4 and inclination of drive arm 8, to produce zoom or tilt motion of the telescope. These motions will be goniometric. It is to be appreciated that some laparoscopes have optically cranked lower ends. Thus, the field of view of the laparoscope is not axially aligned with the laparoscope, but is off-set to one side. It may, therefore, be desirable to rotate the laparoscope constituted by the telescope and the camera about its longitudinally axis in order to obtain a desired view of the interior of a patient. Consequently, the camera 11 may be provided with a motor adapted to rotate the entire camera and telescope as indicated schematically by the arrow 63 in Figure 1. The motor provided to rotate the camera 11 may be located in the camera housing or may preferably be located in the motor housing 7 being connected to the camera by a drive such as a Bowden cable.

Claims: A goniometric robotic arrangement incorporating a telescope (10) adapted to be inserted into a patient (6) through an incision (12) in the abdomen of the patient, the arrangement comprising a support arrangement (4) supporting a support beam (5) so that a terminal portion of the support beam (5) can be located above the patient (6), the support arrangement incorporating a drive mechanism to effect upward and downward movement of the support beam (5), the support beam supporting a drive arm (8) by means (7) adapted to rotate the drive arm about a substantially vertical axis (13) which, in use of the arrangement, is coincident with the incision (12) in the abdomen of the patient (6), characterised in that there is a loose articulation (9) connecting the free end of the drive arm (8) to part of the telescope (10), there being drive means (15) provided to adjust the angle of inclination of the drive arm (8) relative to the horizontal, there being control means to synchronise the upward and downward movement of the support arrangement (4) supporting the support beam (5) and the change of angle of inclination of the drive arm (8) such that the movement of the lower end of the telescope (10) which is passed through the said incision (12) in the patient (6), is goniometric, there being two light sources (20, 21) generated intersecting beams of light (22, 23), the intersecting beams of light being adjusted to intersect at a position a predetermined distance beneath the upper end of the drive arm (8) to define the point of incision (12) of the patient. An arrangement according to Claim 1 wherein the means adapted to adjust the angle of inclination of the drive arm comprise a crown wheel-and-pinion device. An arrangement according to Claim 2 wherein the crown wheel-and pinion device is driven by a low torque motor. An arrangement according to any one of the preceding Claims wherein the means adapted to rotate the drive arm (8) comprise a motor contained within a motor housing (7), a substantially vertical drive shaft driven by the motor being connected to the upper end of the drive arm. An arrangement according to any one of the preceding Claims wherein the lower end of the telescope is optically cranked, and means are provided to rotate at least the lower end of the telescope relative to the axis of the telescope.

Inventors: ANDERSON PETER, ANDERSON, PETER
Applicants: ARMSTRONG HEALTHCARE LTD, ARMSTRONG HEALTHCARE LIMITED
Application year: 1996
Main classification: A61B19
IPC codes: B25J17, A61B19, B25J18, A61B1