Ossur i-digits User manual

i-digits™
Component Assembly Guide

This document provides instruction for prosthetists in the assembly of i-digits™ components necessary for
the fabrication of i-digits™ prostheses. The instructions within should be read in full prior to fabrication. It
is highly recommended that the use of this manual is made in conjunction with instruction from a clinician
experienced in the use of i-digits™.
Refer to www.touchbionics.com/downloads/document-library to ensure you have the latest copy of this docu-
ment.
This symbol signifies important information and is used throughout the manual.
i-digits™ component assembly guide

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1.0 Wristband, Dummy Positioning and Digit Assembly 4
1.1 Positioning of the Socket Terminal Dummy 4
1.2 Removal of the Digit from the Knuckle 5
1.3 Extra Small and Medium Digit Assembly 5
1.4 Knuckle Mounting Plate 6
1.5 Attachment of the Knuckle Mounting Plate 7
1.6 Attachment of the Digit to the Knuckle Assembly 7
2.0 Transfer of Alignment 8
2.1 Thumb Alignment 8
2.2 Knuckle Dummies 8
3.0 Inputs and Finishing Options 10
3.1 LP Remote Electrode Domes 10
3.2 Check Socket Electrodes 10
3.3 LP Compact Electrode 11
3.4 FSR 11
3.5 Knuckle Fairing Options 12
4.0 Assembly 13
4.1 Thumb Rotator Assembly – Setting and Assembly 13
4.2 Attaching the Thumb 14
4.3 Wristband Wiring Connections 16
4.4 Connecting the Digits to the Wristband 17
4.5 Removing the Digit Wires 18
4.6 Connecting the Electrodes to the Wristband 18
4.7 Removing the Electrode Cables 20
4.8 FSR PCB 21
4.9 Completing the Wristband Assembly 22
5.0 Digit Covers 24
5.1 Attaching the Digit Covers 24

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1.0 Wristband, Dummy Positioning and Digit Assembly
1.1 Positioning of the Socket Terminal Dummy
Place the Socket Terminal Dummy on the Dorsal surface
of the positive cast (fig. 1). The position should be central
to the midline of the wrist and elbow joints. A distance of
30mm should be left between the Socket Terminal Dum-
my and the center of the wrist joint to enable good range of
movement at the wrist (fig. 2).
Fig. 1:
Final position of Wristband
Fig. 3:
Midline
Fig. 2:
30mm

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1.2 Removal of the Digit from the Knuckle
Use the T6 Screwdriver to remove the M3 Grub Screw from
the Knuckle Assembly (fig. 4).
The digit can now be freely disengaged from the Knuckle
Assembly.
Fig. 4:
Fig. 5:
Fig. 6:
1.3 Extra Small and Medium Digit Assembly
Depending on the size of the kit, the Knuckle Mounting
Plate will vary in shape.
Figure 5 shows a Medium Digits Assembly.
Figure 6 shows an Extra Small Digit Assembly.

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1.4 Knuckle Mounting Plate
The Knuckle Mounting Plate will support 4 digits.
This Mounting Plate can be cut to suit the number of digits
required for the user (fig. 7).
Knuckle Mounting
Modified Knuckle Mounting
Fig. 7:

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1.5 Attachment of the Knuckle Mounting Plate
Use the T6 Screwdriver to attach the Knuckle Assembly to
a Multiple Knuckle Mounting Plate using three M2 x 6mm
Torx Screws.
Lamination tabs can be bent or shortened as appropriate.
Consider fabrication before cutting and removing tabs,
since some tab length will be needed for fixation of the
plate to the frame (fig. 8).
Take care not to over tighten screws.
Attach each digit using the supplied screws.
Screws are recommended to be single use.
1.6 Attachment of the Digit
to the Knuckle Assembly
Firmly place the digit into the Knuckle Assembly.
Fig. 8:
Fig. 9:
Pre-flex the digit slightly to aid the attach-
ment of the digit.
Screws supplied are recommended for
single use only. Always use new screws for
final assembly.
Insert the M3 grub Screw using the T6
torque driver provided, set to 1.0Nm (fig. 9).

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2.0 Transfer of Alignment
2.1 Thumb Alignment
The use of the Thumb Alignment Plate is to aid the position
of the Thumb Mounting Plate (fig. 10).
Screw the thumb alignment plate onto the index position
Knuckle Mounting Plate using three M2x5 mm screws.
Depending on the handedness, attach the thumb rotation
assembly to the correct side of the alignment plate (fig. 11)
using three M2x5 mm screws.
2.2 Knuckle Dummies
Single knuckle dummies are used to aid transfer of align-
ment. Attach the Single Knuckle Dummies to the Knuckle
Mounting Plate using three M2x16mm Countersunk Torx
Screw and the T6 Screwdriver (fig. 12).
Fig. 10:
Left hand
Right hand
Fig. 11:
Fig. 12:

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Insert the Alignment Bars into the Single Knuckle Dum-
mies and lock each in place using M2 x 5mm Countersunk
Torx Screw and the T6 Screwdriver (fig. 13).
Fig. 13:

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3.0 Inputs and Finishing Options
3.1 LP Remote Electrode Domes
The electrode domes will be assembled into the silicone
using the parts shown in figure 14.
Figure 15 shows how the dome will look once fabricated
into the silicone.
3.2 Check Socket Electrodes
During the check socket process, the check socket elec-
trodes shown in figure 16 may be used.
This allows the position of the electrode to be moved dur-
ing the test fitting stage.
Lamination
Dome Dummy
Silicone
Dome Dummy
Single Suspension
Double Suspension
Fig. 14:
Fig. 15:
Fig. 16:

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Fig. 17:
3.3 LP Compact Electrode - available 2019
Figure 17 shows the LP Compact electrodes along with the
corresponding dummies in figure 18.
3.4 FSR
Figure 19 shows the FSR control method.
LP Compact
Lamination Dummy
LP Compact
Suspension Dummy
Fig. 18:
Fig. 19:

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Fig. 21:
Fairing
Knuckle Dummy
3.5 Knuckle Fairing Options
Components for direct lamination are shown in figure 20.
Components for non-laminated fairings are shown in fig-
ure 21.
Fig. 20:

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Fig. 22:
Fig. 23:
Clutch Plate
4.0 Assembly
Hand tighten with fingers and then turn a further 120 to
150° to give the desired thumb friction depending on pa-
tient preferences (fig. 23), using the 8mm Spanner. The
wire will now travel down through the centre of the spigot.
4.1 Thumb Rotator Assembly –
Setting and Assembly
The full thumb rotator assembly is illustrated (fig. 22). To
increase the force required to rotate the thumb, remove
the Nut Cap and use the 8mm Spanner to tighten the M4
Locking Nut. The grub screw will need to be loosened to
tighten the nut.
Ensure the Clutch Plate is not contaminated,
as this will aect performance.

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4.2 Attaching the Thumb
Remove the base cap on the thumb rotator assembly by
removing the two M2x5mm Screws (fig. 24).
Remove the knuckle cover from the thumb assembly by
removing the two M2x4mm Screws (fig. 25).
Remove the knuckle assembly from the thumb assembly
by removing the M3 Grub Screw (fig. 26).
Screw the knuckle onto the thumb rotator assembly using
3 M2x5 mm Screws (fig. 27).
Fig. 24:
Fig. 25:
Fig. 26:
Fig. 27:

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Fig. 28:
Fig. 29:
Fig. 30:
Fig. 31:
Using a torque driver set to 1Nm, re-attach the thumb to
the single knuckle assembly (fig. 28).
Slide the knuckle fairing over the back of the thumb and
attach using two M2x5 mm Screws (fig. 29).
Thumb digit wire should be fed through the central hole
in the thumb assembly exiting at the base cap end.
Re-attach the base cap, using the screws previously re-
moved (fig. 24).
Add connector onto each of the thumb digit wires as
shown. Ensuring ‘tooth’ is fully secured into connector
(fig. 30)
After diagnostic fitting thumb wire connector should be
removed to enable fabrication of definitive prosthesis.
To remove connector from thumb wire; place small flat
screwdriver under tab of connector and lift up. Gently pull
on digit wire to release from connector.
When inserting the M3 grub Screw into
the single knuckle a T6 torque driver, set to
1.0Nm, must be used (fig. 28).
Screws supplied are recommended for
single use only. Always use new screws for
final assembly.
After each time of removal of a connector,
a new connector should be used on the
thumb wires.

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4.3 Connecting the Digits to the Wristband
Fig. 32:
Index ThumbMiddle RingLittle
Fig. 33:
Fig. 34:
Slide the protective PCB cover out of the bellows assembly
(fig. 33).
4.4 Wristband Wiring Connections
Remove the bellows by pulling them over the socket end of
the assembly, as shown, to expose the PCB (fig. 32).
Take care not to damage the PCB.
3
4

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Slide the digit wires through the aperture at the front of the
bellows assembly (fig. 35).
Fig. 37:
The digit wire connectors should be inserted into the bel-
low PCB. A click should be felt when fully inserted.
Fig. 35:
Fig. 36:
Fig. 38:

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Create slack in the digit wires, so that the bellow assembly
flexes without tension in the digit wires (fig. 39).
Fig. 39:
If there is not enough slack, flexing of the
bellows may lead to failure of the digit wire
connection.
4.5 Removing the Digit Wires
To remove a digit wire, pull on connector piece to remove
the digit wires of the required digit.
Once the digit wires are connected, slide the electrode ca-
bles through aperture shown in figure 41.
Connect the cables following the mapping shown in figure
40.
To mate the connectors, the mating axes of both con-
nectors must be aligned aand then pushed together. The
“click” will confirm fully mated connection.
Do not attempt to insert on an extreme
angle or the connector will break.
Take care not to damage the PCB.
Signal 1
Ground
Signal 2
4.6 Connecting the Electrodes to the Wristband
Fig. 40:
Fig. 41:

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The signal cables inserted in signal 1 position should be
routed as shown in figure 42.
Fig. 42:
Check that there is no tension in the cables when flexed as
shown in figure 43 (similar to the digit wires approach as
shown in figure 39).
Before completion of the next stage, check
that digits and electrodes are all functioning
correctly.
Fig. 43:

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Fig. 44:
Fig. 45:
Fig. 46:
4.7 Removing the Electrode Cables
If the electrode cables need to be repositioned, use the ex-
traction tool supplied (fig. 44).
Insert the end portion of the tool under the connector
flanges and pull o vertically, in the direction of the con-
nector mating axis (fig. 45 and 46).
Pull the connector up vertically with the re-
moval tool or the connector will be damaged.