Mechanical interface for a computer system
A mechanical interface for providing high bandwidth and low noise mechanical input and output for computer systems. A gimbal mechanism includes multiple members that are pivotally coupled to each other to provide two revolute degrees of freedom to a user manipulatable about a pivot point located remotely from the members at about an intersection of the axes of rotation of the members. A linear axis member, coupled to the user object, is coupled to at least one of the members, extends through the remote pivot point and is movable in the two rotary degrees of freedom and a third linear degree of freedom. Transducers associated with the provided degrees of freedom include sensors and actuators and provide an electromechanical interface between the object and a computer. Capstan band drive mechanisms transmit forces between the transducers and the object and include a capstan and flat bands, where the flat bands transmit motion and force between the capstan and interface members. Applications include simulations of medical procedures, e.g. epidural anesthesia, where the user object is a needle or other medical instrument, or other types of simulations or games.
1. An apparatus, comprising
a base;
a first extension member having a first end and a second opposed end, the second end coupled to the base, the first extension member pivotable about a first axis;
a second extension member having a first end and a second opposed end, the second end coupled to the base, the second extension member pivotable about a second axis, wherein the first axis and second axis intersect;
a first central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the first extension member;
a second central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the second extension member, the first end of the first central member and the first end of the second central member converge toward one another at an interface region to form a closed loop, the interface region adapted to receive a removable user graspable object, wherein the user graspable object is moveable with respect to the base;
a sensor configured to measure position of the user graspable object, the sensor configured to provide at least one sensor signal associated with the position of the user graspable object to a processor; and
an actuator coupled to a portion of the linkage and configured to output a force to one or more of the members based on the an activating signal received from the processor, wherein the activating signal is based at least partially on the sensor signal.
2. The apparatus of claim 1 , wherein each of the first extension member, the second extension member, the first central member and the second central member are configured to move when the user graspable object is moved.
3. The apparatus of claim 1 , wherein the user graspable object is configured to be moved in a linear degree of freedom with respect to the base.
4. The apparatus of claim 1 , wherein the activating signal is operative to compensate for a gravitational force resulting from a weight of the actuator to allow the user graspable object to be moved substantially free from gravitational force.
5. The apparatus of claim 1 , further comprising a computer system coupled to the sensor and the actuator, the computer system configured to execute a video game simulation, wherein the host computer is configured to output display signals adapted to display images of the video game to a display screen, wherein the host computer is configured to manipulate a graphical object in the video game simulation in response to receiving the sensor signal.
6. The apparatus of claim 1 , further comprising a computer system coupled to the sensor and the actuator, the computer system configured to execute a medical simulation, wherein the host computer is configured to output display signals adapted to display images of the medical simulation to a display screen, wherein the host computer is configured to manipulate a graphical object in the medical simulation in response to receiving the sensor signal.
7. The apparatus of claim 1 , further comprising a band drive mechanism coupled to the actuator and one or more of said members, the band drive mechanism configured to transmit the force generated by the actuator to the user graspable object, the band drive mechanism configured to transmit the movement applied to the user graspable object to the sensor.
8. A method, comprising:
providing an interface apparatus having a base, the interface apparatus including a closed loop linkage mechanism coupled to the base and having a first extension member having a first end and a second opposed end, the second end coupled to the base, the first extension member pivotable about a first axis, the linkage mechanism including a second extension member having a first end and a second opposed end, the second end coupled to the base, the second extension member pivotable about a second axis, wherein the first axis and second axis intersect, the linkage mechanism including a first central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the first extension member and a second central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the second extension member, the first end of the first central member and the first end of the second central member located proximate to one another and adapted to receive a removable user graspable object, wherein the user graspable object is moveable with respect to the base;
measuring a position of the user graspable object as the user graspable object is moved via a sensor coupled to the interface apparatus; and
outputting a force that is to be felt on the user graspable object using an actuator coupled to said interface apparatus, wherein the actuator outputs the force based on at least on the measured position of the user graspable object from the sensor.
9. The method of claim 8 , wherein each of the first extension member, the second extension member, the first central member and the second central member are configured to move when the user graspable object is moved.
10. The method of claim 8 , wherein the user graspable object is configured to be moved in a linear degree of freedom with respect to the base.
11. The method of claim 8 , wherein the activating signal is operative to compensate for a gravitational force resulting from a weight of the actuator to allow the user graspable object to be moved substantially free from gravitational force.
12. The method of claim 8 , further comprising executing a video game simulation on a computer system coupled to the sensor and the actuator, wherein the host computer is configured to output display signals adapted to display images of the video game to a display screen, wherein the host computer is configured to manipulate a graphical object in the video game simulation in response to receiving the sensor signal.
13. The method of claim 8 , executing a video game simulation on a computer system coupled to the sensor and the actuator, the computer system configured to execute a medical simulation, wherein the host computer is configured to output display signals adapted to display images of the medical simulation to a display screen, wherein the host computer is configured to manipulate a graphical object in the medical simulation in response to receiving the sensor signal.
14. The method of claim 8 , further comprising transmitting the force from the actuator to the user graspable object via one or more of said members using a band drive mechanism, wherein the band drive mechanism is configured to transmit the movement applied to the user graspable object to the sensor.
15. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a method, the method comprising:
sensing movement of a user graspable object with respect to a ground, the user graspable object coupled to an interface of an interface apparatus having a base, the interface apparatus including a first extension member having a first end and a second opposed end, the second end coupled to the base, the first extension member pivotable about a first axis, the interface apparatus including a second extension member having a first end and a second opposed end, the second end coupled to the base, the second extension member pivotable about a second axis, the interface apparatus including a first central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the first extension member and a second central member having a first end and a second opposed end, wherein the second end is pivotably coupled to the first end of the second extension member, the first end of the first central member and the first end of the second central member configured to converge at a location proximate to one another at the interface;
measuring a position of the user graspable object as the user graspable object is moved via a sensor coupled to the interface apparatus; and
outputting a force signal to an actuator coupled to the user graspable object, wherein the actuator outputs a force corresponding to the force signal to be felt on the user graspable object, wherein the actuator outputs the force based on at least on the measured position of the user graspable object from the sensor.
16. The method of claim 15 , wherein each of the first extension member, the second extension member, the first central member and the second central member are configured to move when the user graspable object is moved.
17. The method of claim 15 , wherein the user graspable object is configured to be moved in a linear degree of freedom with respect to the base.
18. The method of claim 15 , wherein the activating signal is operative to compensate for a gravitational force resulting from a weight of the actuator to allow the user graspable object to be moved substantially free from gravitational force.
19. The method of claim 15 , further comprising executing a video game simulation on a computer system coupled to the sensor and the actuator, wherein the host computer is configured to output display signals adapted to display images of the video game to a display screen, wherein the host computer is configured to manipulate a graphical object in the video game simulation in response to receiving the sensor signal.
20. The method of claim 15 , executing a video game simulation on a computer system coupled to the sensor and the actuator, the computer system configured to execute a medical simulation, wherein the host computer is configured to output display signals adapted to display images of the medical simulation to a display screen, wherein the host computer is configured to manipulate a graphical object in the medical simulation in response to receiving the sensor signal.
21. The method of claim 15 , further comprising transmitting the force from the actuator to the user graspable object via one or more of said members using a band drive mechanism, wherein the band drive mechanism is configured to transmit the movement applied to the user graspable object to the sensor.