Determination of finger position
A prescription is provided which specifies constraints, e.g., the type (revolute and/or prismatic) and the number of joints which may be included between any two position-sensing elements (PSEs), where the joints connect the links of a kinematically constrained multi-articulated structure, whereby the defining parameters of the structure may be determined using the spatial placement of the two PSEs and the kinematic constraints of the multi-articulated structure, and where at least the spatial placement of one link is not directly measured. Also provided are preferred placements of PSEs and goniometers on a kinematically constrained multi-articulated structure which will allow determination of the spatial placement of the links, where at least the spatial placement of one link is not directly measured. Revolute joint models of the articulations of the entire human body, as well as preferred PSE and goniometer locations, are provided. An algorithm is provided for determining the joint angles for a finger modeled as a 4-link planar manipulator with one PSE affixed to the fingertip and one PSE affixed to the metacarpus.
1. A system, comprising:
a mount configured to be coupled to an appendage;
a position sensor including a position sensing element coupled to the mount, the position sensor configured to send a signal associated with a spatial position of the position sensing element with respect to a predetermined reference point; and
a data processor configured to generate an output signal associated with the spatial position of the position sensing element based on the signal, said data processor configured to determine a spatial position of the mount, the spatial position of the mount indicative of a distance and a direction from the predetermined reference point.
2. The system of claim 1 , wherein the mount includes a ring.
3. The system of claim 2 , wherein the ring includes an elastic band.
4. The system of claim 1 , wherein the mount includes a clip having flexible and separable portions.
5. The system of claim 1 , wherein the mount includes a thimble.
6. The system of claim 5 , wherein the thimble includes elastic material.
7. The system of claim 1 , wherein the mount includes an artificial fingernail having a support configured to be adhesively attached to a fingernail on the appendage.
8. The system of claim 1 , wherein the position sensing element includes at least one of an electromagnetic energy transmitter and an electromagnetic energy receiver.
9. The system of claim 1 , the position sensing element being a first position sensing element, the system further comprising a second position sensing element configured to be positioned apart from the first position sensing element.
10. The system of claim 1 , the position sensing element being a first position sensing element configured to be positioned on a distal link of the appendage, the system further comprising a second position sensing element configured to be positioned on a proximal link of the appendage and separated from the distal link by an intermediate link.
11. The system of claim 10 , wherein the data processor is configured to calculate the spatial position of the intermediate link based on the first position sensing element and the second position sensing element.
12. The system of claim 1 , further comprising a support structure configured to apply a force reflection.
13. A method, comprising:
generating a signal associated with a spatial position of a position sensing element with respect to a predetermined reference point, the position sensing element being coupled to a position sensor, the position sensor being coupled to a mount configured to be worn on an appendage;
transmitting the signal to a data processor;
generating an output signal associated with the spatial position of the position sensing element based on the transmitted signal; and
calculating a spatial position of the mount based on the output signal, the spatial position of the mount indicative of a distance and a direction from the predetermined reference point.
14. Processor executable code stored on a processor-readable medium, the code comprising:
code to generate a signal associated with a spatial position of a position sensing element with respect to a predetermined reference point, the position sensing element being coupled to a position sensor, the position sensor being coupled to a mount configured to be worn on an appendage;
code to transmit the signal to a data processor;
code to generate an output signal associated with the spatial position of the position sensing element based on the transmitted signal; and
code to calculate a spatial position of the mount based on the output signal, the spatial position of the mount indicative of a distance and direction from the predetermined reference point.