MXPA97002287A

MXPA97002287A - Lever from ma

Info

Publication number: MXPA97002287A
Application number: MXPA/A/1997/002287A
Authority: MX
Inventors: A Luce David
Original assignee: Leica Inc
Priority date: 1994-10-28
Filing date: 1997-03-26
Publication date: 1997-06-01

Abstract

The present invention relates to an improved ophthalmologist instrument having optical means for testing an eye of a patient, characterized in that it comprises: a frame, a support for the optical means connected to the frame, a motor for moving support in any vertical direction, the motor It works in response to a means of communication, lever means to control the movement of the support in the three dimensions, those of lever are inclined for the horizontal movement of the support and rotated for the movement of the support, and an actuator connected to the means of and which are positioned to operatively engage the switching means during the rotation of the lever in any direction, whereby the verical movement is controlled by the rotation of the lever and is independent of the amount of rotation.

Description

CONTROL LEVER BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved control lever, used for the alignment of a three-dimensional ophthalmic instrument, and more particularly, to a control lever that requires a minimum rotational movement. 2. Description of the Previous Technique Many ophthalmic instruments require alignment of a test axis with the center of an eye of the patient and an element of the instrument that is to be spaced at a selected distance from the eye. One of such instruments, the non-contact tonometer, has been used by physicians in their ophthalmic practice for more than 20 years. The initial contactless tonometers, manufactured by the American Optical Corporation, used a joystick, a handle or sleeve extending from a mounted ball to provide pivotal movement around the center of the ball, to move the instrument in a plane horizontal (XZ). To move the test axis Ref.24401 horizontally in the X direction towards the center of the 0 0 of the patient, the control lever is inclined in a corresponding direction.To move the element in the Z direction toward or away from the eye, the joystick is inclined in the corresponding direction Obviously, the compound horizontal movement can be obtained by moving the joystick in a direction between the orthogonal directions mentioned above.The movement in the vertical axis Y in these initial contactless tonometers, was provided by a separate knob attached or linked by a belt or band to a threaded shaft mounted for rotation on the carrier and which engages a nut on the support to provide vertical movement of the test shaft .The "on" button used to drive the burst of air of the initial contactless tonometers, was located in the center of the knob used to control movement on the Y axis, vertical The later models of the contactless tonometers produced by Reichert-Jung Ophthal ic Instruments (a successor of American Optical Corporation) and Tokyo Optical Company (Topcon) combined the control of the vertical Y-axis and the "on" button on the lever of command. An example of this type of joystick is taught by Japanese Publication No. 4-50562. Such controls have several disadvantages as taught by the Japanese publication mentioned above. A problem encountered resulted from the twisting of the wires used to connect the "on" button to the electronic devices of the instrument and the cost associated with eliminating the problem of twisted wires or cables. Another disadvantage of rotating the control lever to control vertical movement was that the physician could not perform vertical movement when he is holding the control lever in the conventional manner because vertical movement frequently required one or more revolutions of the Joystick to vertically place the test axis in the center of the eye. Also, many physicians find it difficult to maintain a horizontal location while adjusting the vertical location of the instrument. A system for determining the position of a test axis relative to the center of the eye, as well as the distance of an element from the eye, is taught in U.S. Pat. No. 4,881,807 commonly owned. This patent describes an optical alignment system having a visual indicator to indicate the relative position of the test axis, and teaches the use of a joystick to manually place the test axis or the use of three electric motors controlled by the information obtained from the optical alignment system for the automatic placement of the instrument.

BRIEF DESCRIPTION OF THE INVENTION An optical instrument includes a lever mounted on a ballmanually controlled, or joystick, for collating the optical means of the instrument, including a test axis, in relation to a patient's eye. The optical means are fixed to a vertically movable support which in turn is carried by a horizontally movable carrier. The joystick mechanically moves the carrier in a horizontal plane relative to a target, to the center of the test axis and spaced the optical averages at an appropriate distance from the eye. The control lever is connected to a motorized driving means having a lifting motor for moving the support and optical means in any vertical direction. An actuator extends from the control lever and is arranged or arranged to alternately couple a pair of switches connected to the motorized drive means, so that the activation of the lifting motor and its direction of rotation can be controlled with a rotary movement minimum of the control lever around its longitudinal axis. Accordingly, the physician can now hold the control lever in a conventional manner and is not required to change its grip to achieve vertical movement of the test axis during the alignment process.

BRIEF DESCRIPTION OF THE DRAWINGS The nature and mode of operation of the present invention will now be described more fully in the following detailed description of the preferred embodiments, taken with the figures of the accompanying drawings, in which: Figure 1 is a perspective view of an improved ophthalmic instrument, formed in accordance with the present invention; Figure 2 is a top plan view of a control lever and switch means of the pre-sentate invention; Figure 3 is a sectional view taken generally along line 3-3 in Figure 2; Figure 4 is a side sectional view of a lifting motor and the limit limit detector associated with the present invention; Figure 5 is a sectional view taken generally along the line 5-5 in Figure 2; and Figure 6 is a bottom plan view of the control lever.

DETAILED DESCRIPTION An improved ophthalmic instrument in the form of a non-contact tonometer (NCT) is shown in Figure 1 and generally designated 10. The NCT 10 is conventional in that it includes a frame 12 having a movable hopzontal carrier 14, a support 16 having axes 18 slidably mounted by the carrier tubes 20 for movement of the support vertically relative to the carrier 14 and horizontally with the carrier, optical means 22 fixed to the support 16 for testing an eye of a patient centered along a test axis 23 of the optical means, and a joystick 24 for controlling the movement of the optical means 22 in three dimensions. The NCT 10 is preferably equipped with an optical alignment system of a type described in U.S. Pat. No. 4,881,807 commonly owned. In accordance with the present invention, an elongation motor 26 is provided for vertical upward and downward, automatic movement of the support 16 and the optical means 22 in response to a lift switch 28a and a descent switch 28b triggered or alternatively activated by an actuator 30. The actuator 30 extends radially from the control lever 24 and activates the incident switching means 28a, 28b for a minimum rotation of the control lever in any direction about its longitudinal axis, so which facilitates the vertical positioning of the test axis 23 in relation to the eye. As best seen in Figures 2, 3, and 6, the joystick 24 is generally of a conventional structure except for the actuator 30. The joystick 24 includes a handle portion 31 and is mounted in a known manner on the carrier 14 by a teflon ball 32 received inside a complementary cavity 34 and having slot means 36 for accommodating a set screw 38 which allows the coupled rotation of the control lever and the receptacle about the longitudinal axis of the lever of control in addition to the movement of inclination of the control lever inside the cavity or receptacle. The control lever 24 also includes a rounded Teflon leg 40, arranged to engage a flat platform 42 fixed to the structure 12 throughout the range of movement of the carrier 14, and ignition switching means 44 connected to a cable 46 to activate the optical means 22. As shown in FIG. 6 only, a retaining arm 48 is fixed to a bottom side of the carrier 14 for accommodating below the incident platform 42 for the lifting movement exerted on the joystick 24 The actuator 30 is fixed to a cavity or receptacle 34 to extend radially outward from the control lever 24 between the switches 28a, 28b in a rotational reference position, such that the same operatively couples a switch damper 50a to the switch. activating the incident lifting switch 28a with respect to a slight rotation of the control lever 24 in a direction in the clockwise direction of the hands; loj and the same operatively couples an a ort. switch guide 50b for activating the incident down switch 28b with respect to the light rotation of the control lever 24 in a clockwise direction. The commuters 28a, 28b are preferably normally aperture switches of the general type known as "nucro" switches. Obviously, other similar switches are possible; . The switches 28a, 28b are connected by wires 51 to suitable electronic motor control devices (not shown), preferably of a type described in U.S. Pat. cope-tooth, commonly owned, entitled "Joystick Override Control" which has the proxy registration number B6724. Referring now to Figures 2, 4, and 5, the hoisting motor 26 is fixed to a lower element 52 of the bracket 16 and includes an internally threaded rotor (not shown) for engagement with a threaded rod 54 that holds a portion. upper fixed to the carrier 14 by a mounting bracket 55 and a lower portion extending downward through the carrier 14 and the lower element 52. A motor suitable for use in the practice of the present invention is a stepper motor bidirectional, 4.6 Watt, 12 Volt DC, 36343-12 available from Haydon Switch and Instrument, Inc. An upper limit switch 56 and lower limit switch 58 are mounted on a brace or platform 57 and connected to the devices electronic motor control cables 59, and a tab 60 is fixed for travel with the lower element 52 to interrupt the light sensors on the upper limit switch 56 once a more upper travel limit and a lower limit switch 58 is reached once it reaches a lower travel limit, whereby the respective limit switch is sent a signal to the electronic control devices of the motor to disable the lifting motor 26 when any limit of travel is reached. A preferred limit switch is the HOA 1881-11 optical transmissive switch model number manufactured by Honeywell. As can be seen from the above description, the NCT is significantly easier to operate than the ophthalmic instruments of the prior art, particularly with respect to the vertical positioning of the test axis 23. To raise the test axis 23, an operator only rotates the control lever 24 in the clockwise direction through a minimum angle, until the actuator 30 operatively couples the switch damper 50a, on the switch 28a, whereby the internally threaded rotor is caused to ] lift motor 26 rotates in a first direction forcing the motor and support 16 fixed thereto to travel upwards along a threaded rod 54. Depending on the type of switch 28a, the upward travel of optical means 22 it can be stopped either by returning the control lever to its original reference position by moving away from the coupling with the switch 50a of the switch, or by repeating the We are going through a "turn and come back" cycle used to start the upward movement. The downward positioning of the test axis 23 is started in a similar but opposite manner by the rotation of the control lever 24 in the counterclockwise direction from its reference position until the actuator 30 operatively couples the switch 50b of the commutator. Accordingly, the present invention allows an operator to move the optical means 22 and the test axis 23 through its full range of vertical travel with a light wrist movement and without changing the grip on the joystick. Although the present invention is directed to the motorized movement activated by the switch in the opposite vertical directions (Y), the motorized movement in all three dimensions has been described previously, for example in U.S. Pat. No. 4,881,807 mentioned above, in column 6, lines 31-44 and figure 7, and therefore it is contemplated to provide similar switching means for motorized movement in the horizontal X and Y directions. It is noted that in relation to this date, the best method known by the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects to which it relates. Having described the invention as above, it would revert as property contained in the following

Claims

R E I V I N D I C A C I O N S

1. "An improved ophthalmic instrument having optical means for testing a patient's eye, characterized because it comprises: a frame, a support for the optical means connected to the frame, a motor for moving the support in any vertical direction, the motor it functions in response to a switching means, lever means for controlling the movement of the support in all three dimensions, the lever means are inclined for horizontal movement of the support and rotated for vertical movement of the support, and an actuator connected to the lever means and which are positioned to operatively couple the switching means during the rotation of the lever in any direction, whereby the vertical movement is controlled by the rotation of the lever and is independent of the amount of the rotation.

2. The improved ophthalmic instrument according to claim 1, characterized in that the actuator r is an element extending from the lever means and the switching means include two switches placed on the opposite sides of the actuator, one of the two switches operates the engine in one direction and the other of the two switches operates the engine in the other direction.

3. The improved ophthalmic instrument according to claim 2, characterized in that it also includes a carrier, the holder is slidably connected to the carrier for movement in a vertical direction and the carrier is slidably connected to the frame for movement in a horizontal plane .

4. The improved ophthalmic instrument according to claim 3, characterized in that a threaded shaft extends vertically from the carrier, the motor is connected to the support and has an internally threaded rotor that operatively couples the shaft.

5. The improved ophthalmic instrument according to claim 3, characterized in that the lever means includes a ball, a cavity or receptacle for mounting the lever means to the holder, the ball is universally movable in the cavity or receptacle, a handle or sleeve extending from the ball, and a leg portion extending from the ball opposite the handle or sleeve, and the frame includes a horizontal platform that frictionally engages the leg portion.

6. The improved ophthalmic instrument according to claim 4, characterized in that the lever means includes a ball, a cavity or receptacle to mount the lever means to the holder, the ball is universally movable in the cavity or receptacle, a handle or sleeve that extends from the ball, and a leg portion extending from the ball opposite the handle or sleeve, and the frame includes a horizontal platform that frictionally engages the leg portion.

7. The improved ophthalmic instrument according to claim 6, characterized in that the leg portion has a spherical segment surface.

8. The improved ophthalmic instrument in accordance with claim 6, characterized in that it also includes switching means in the handle or sleeve to initiate a test by the instrument.