Joint and digit
This disclosure relates to the field of prosthetics, more specifically to a pinless anthropomorphic hinge or joint, and a digit comprising one or more phalanges connected by and articulating around pinless joints, whereby the joints provide compliant movement in more than one plane. This disclosure also relates to modular prosthetic systems comprising multiple digits, in particular for partial-hand replacements.
1. An external prosthetic biomimetic digit comprising:
a first phalange comprising a proximal end, a palmar side, a dorsal side, and a first hole positioned towards the proximal end of the palmar side of the first phalange;
a second phalange comprising a distal end, a palmar side, a dorsal side, and a second hole positioned towards the distal end of the palmar side of the second phalange; and
a stabilizing cylinder comprising a length, a diameter, and a third hole passing through the length, wherein:
the proximal end is positioned adjacent to the distal end,
the palmar side of the proximal end of the first phalange is rounded to form a first arc,
the palmar side of the distal end of the second phalange is rounded to form a second arc such that the first arc and the second arc form a nip,
the stabilizing cylinder is positioned in the nip, and
the proximal end is movably attached to the distal end by a first loop secured through the first hole and the second hole, a second loop secured through the first hole and the third hole, and a third loop secured through the second hole and the third hole such that the first loop, the second loop, and the third loop form a triangular formation.
2. The digit of claim 1 , wherein the stabilizing cylinder further comprises:
a first end and a second end;
a first flange positioned at the first end; and
a second flange positioned at the second end.
3. The digit of claim 1 , further comprising:
a base comprising a third hole; and
a fourth loop, wherein:
the second phalange further comprises a proximal end and a fourth hole positioned towards the proximal end of the palmar side of the second phalange, and
the proximal end of the second phalange is movably attached to the base by the fourth loop secured through the third hole and the fourth hole.
4. The digit of claim 1 , further comprising:
a first tension guide positioned along the dorsal side of the first phalange;
a second tension guide positioned along the dorsal side of the second phalange; and
a tension cord comprising a first end and a second end, wherein:
the first phalange further comprises a distal end with a fifth hole positioned towards the dorsal side and the distal end of the first phalange,
the base further comprises a sixth hole,
the tension cord is positioned in the first tension guide and the second tension guide,
the first end of the tension cord is secured to the fifth hole, and
the second end of the tension cord is secured to the sixth hole.
5. The digit of claim 1 , further comprising:
a cord comprising a first end and a second end, wherein:
the first phalange further comprises a seventh hole positioned towards the palmar side and the distal end of the first phalange,
the base further comprises an eighth hole,
the first end of the cord is secured to the seventh hole,
the second end of the cord is secured to the eighth hole, and
the cord passes over the stabilizing cylinder.