MATRIX – A COMPLETELY BODY POWERED ACTIVE PROSTHETIC MECHANICAL FINGER
Author: Hiren Babariya (Prosthetist & Orthotist- Gold medalist)
To improve and restore the function to the optimal level is the basic goal of any kind of hand prosthesis.
Disclosed is a MATRIX- completely body powered active prosthetic mechanical finger for the patient with a partial/ full finger or multiple finger amputation, helps to mimic the functions of a normal human finger providing active flexion and extension of both PIP and DIP joints. Depending on amputation level, this finger is controlled by the remaining or adjacent finger. When patient flexes residual stump, it flexes PIP and DIP joints simultaneously providing complete finger flexion.
In this prosthetic finger, there is a said PIP joint section, socket attachment proximal to it, DIP joint section with distal phalanx, middle phalanx connecting both PIP and DIP joint section, wrist band; and a metacarpal band connecting both wrist band and prosthetic finger assembly on the dorsal aspect of the hand for its function.
PIP and DIP joint axes are located centrally in joint sections with small pins circulating them to direct the path of strings (control cables) and rubber extension assist. Middle phalanx, near-like hollow tubular structure; connected to the PIP and DIP joint sections on each side with a central joint axis to provide articulation.
Socket, connecting PIP joint section is donn over the residual stump.
Adjustable metacarpal band is proximally attached to the wrist band and distally to middle phalanx via control cable, guided by the housing over the socket and small pins around PIP joint axis. There is an another kinematic inter-linkage between PIP and DIP joint sections via control cable and rubber extension assist
In matrix finger, when patient flexes residual stump; it creates tension in control cable providing flexion of the PIP joint. At the same time because of inter-linkages, during PIP joint flexion; it also flexes DIP joint simultaneously providing complete finger flexion. During extension of the residual stump, rubber extension assist helps to assist in extension of finger assembly.
· Very low profile design with a good biomechanical concept.
· Because of its innovative design and centrally located joint axes, its system length is very low (only 4-5 mm).
· Because of its centrally located axis, the length of the finger remains same either in flexion or extension and doesn’t create any gape at joint levels during its movement.
· Made up of high durable/ carbon fiber reinforced plastics so it is light in weight and durable.
· Cosmetically more acceptable as available in different color shades as per the skin tone and even easy to make silicone cover over it.
· Very easy to adjust and fit to the patient because of adjustable wrist band and metacarpal band and more comfortable to wear.
· Quick alterations are possible like PIP/ DIP joint flexion angle, tightening or loosening of rubber extension assist or control string as per need at delivery.
· Same finger can also works on tenodesis or anti-tenodesis principle for patient with partial hand amputation.
· Requires Very less maintenance.