A patent filed by Nintendo for a┬áÔÇ£Training Implement, Training System, and Input DeviceÔÇØ has surfaced on the internet, which was originally filed for in October, 2014.┬áIt had an international filing back on September 18, 2015, and publication yesterday via the World Intellectual Property Organization.
Information from the Japanese patent translated to English includes:

Cita:ÔÇ£A training implement (10) comprises a hollow body (12) formed from an aluminum alloy. The body is configured from two grips (12a) provided facing each other across a space, and a connecting section (12b) connecting the two grips. A load sensor (16) is disposed in the connecting section inside the body. The load sensor is a load cell, the strain gauge is bonded on the inside of the body, and the portion of the body to which the strain gauge is bonded functions as a strain element. Consequently, when a user applies force so as to bring the two grips towards each other or applies force so as to separate the two grips, the load thereof is detected by the load sensor.ÔÇØ

HereÔÇÖs some images of the device and their annotations below:





[1] Figure 1 is an illustrative view showing an outline of an embodiment in which the training device and the partial configuration of the present invention, FIG. 1 (A) is a front view of the training device from the front, FIG. 1 (B) is a top view of the training device from the top, FIG. 1 (C) is a schematic diagram showing a schematic configuration of a socket portion provided in the training equipment.

Cita:[25] FIG 25 is an illustrative view showing one example of an input device using a training device shown in FIG. 1

You can check out the original NeoGAF post containing the patent information here.

Fuente

Tiene más pinta de producto QoL que para juegos, y ya recuerdo la infamia que fue ESTO: