A Real-Time Wearable Electromyography Measurement System for Small Animals

This method seeks to measure EMG in small animals without the need for a tethered connection to measurement equipment. Tethering can restrict the animal's movement and lead to certain disadvantages. We started with the question of whether we could address these limitations.

We are currently developing and testing an electrical stimulation device for treating muscles and nerves. Unlike traditional methods that use open loop stimulation for recovery, our approach incorporates closed loop feedback to monitor the effect in real-time. This integration aims to enhance the therapeutic outcomes.

Our focus is on miniaturizing the device so it can be used on live animals without restricting their movement. While some experienced engineering teams may perform similar tests casually, it is challenging for teams with a purely scientific background to achieve this. Our study specifically aims to use a wireless wearable system, and we designed the device with that goal in mind.

One of the key advantages is that we have miniaturized the connectors and the device itself. This design helps to reduce the burden during measurement experiments, especially when working with animal subjects. Our lab aims to advance the research on small animal treatments by developing a bio signal measurement system with closed loop feedback monitoring.

This system enables us to achieve more precise and adaptive therapeutic outcomes, enhancing the effectiveness of treatments. To begin, cut a polytetrafluoroethylene-coated stainless steel wire into a length of 140 millimeters and 60 millimeters. Tie three overhand knots on a 140 millimeter long wire, placing them at 40 and 100 millimeters relative to the knot.

Leave a two millimeter gap from the knot on the short side of the 140 millimeter wires. Then use a soldering iron to partially strip off two millimeters of insulation. On the long side, fully strip off two millimeters of insulation from the end.

For the 60 millimeter wire, remove two millimeters of insulation from one end and 10 millimeters from the other end. After fully removing the insulation, fix the wire by soldering it to the connector accessory. Assemble the metal part connected to the wire into the plastic housing.

Attach the connector to a 3D-printed plastic guide with holes for securing it to the animal skin. Apply biocompatible cyanoacrylate to prevent the soldered part from contacting the incision site. Cut a 0.2 millimeter thick nickel plate and bend it around the connector to shield it, preventing potential damage from the animal.

To begin, using a surgical scissor, make an incision of 5 to 10 millimeters around the lumbar region of the anesthetized rat where the connector will be attached. Then make an incision of approximately 10 to 15 millimeters on the skin over the target muscle, and remove the fascia underneath the skin to expose the muscle. Use sterile trocar to create a passage for the wire to pass from the lumbar incision to the target muscle position.

After preparing the wire electrode and connector assembly, use the trocar to pinch the wire electrodes at the lumbar incision, and carefully pull them through to the target muscle incision. Use a suture needle to insert the electrode wire into the target muscle. Guide the wire that has passed through the muscle back to its insertion point.

Secure it with an overhand knot and cut the remaining wire. After securing the wire electrode in the target muscle, suture the incision site using a 4/0 suture thread. Suture the incision under the connector, ensuring that the entire wire is inserted into the body and securely sutured.

Finally, secure the connector to the rat's dorsal skin using suture thread.