Final Design

Figure 1: Current Design of G-machine

            For the final design of the cross-sectional area measurement device, several components have been changed from the previous device.  This device has been dubbed “the G-machine” by the design team.  As seen in Figure 10,  the tendon is still squeezed into a square as it was in the previous design.  However, the height of the square is no longer determined by tick marks but a hall effects sensor.  The hall effect sensor sends a signal to the micro-controller, represented by the arduino block in the diagram. The arduino takes this signal, and calculates the cross-sectional area of the square the tendon is being squeezed into.  The arduino then sends a signal to an LCD screen that displays the cross-sectional area of the device. 

For securing the measurement attachment to the latch, initially a screw was considered.  However, this was inconvenient and did not translate to a surgery setting. The screw was abandoned for the jig-saw shape that is seen in the diagram.  Another plate is attached to the exposed side when the device is in use.  Therefore the latch and measurement attachment are locked in together by way of this jig-saw design.  The constant force spring is stretched and secured to the back end of the latch by means of a 4-40 screw.  A tendon is therefore strung between the measurement attachment, then the measurement attachment is secured to the latch, and the component is then let go and the spring pulls the whole component back towards the hall effect sensor.  The final result is that the tendon’s cross-sectional area is measured in a standardized method that was not present when calipers were used to measure the cross-sectional area.