The main advantage of this technique is that it offers a significantly less invasive approach. Generally, individuals new to this method will struggle because the implantable device development is a discipline which requires experience both in hardware and software design. Visual demonstration of this method is critical as the endoscopic submucosal implantation is an experimental procedure currently not used in daily practice.
To begin this procedure, place the PCBs on a flat surface. Use a solder paste dispenser with a 0.6 millimeter needle and 60 PSI pressure to manually dispense less than 15 microliters of the soldering paste onto every metallic pad on the PCB. Begin with the top side of the PCB.
With a pair of anti-static tweezers, place all components on the top layer of the PCB. Assign the component positions and components to their numbers. After that, use a PCB hot airgun station at 260 degrees Celsius to solder all components.
Wait until all the solder paste melts. Put away the hot airgun and allow the board to cool to room temperature. Connect the PCB to all other electrical components except for the battery.
Solder the wireless charging communication coil to pads two and three, then connect the antenna to pad one and the PCB electrodes to pads number four and five. Following that, solder the CG-320 battery to pads six and seven. The negative terminal of the battery must be soldered on pad seven.
Be careful while performing the next steps. The device is now powered and is sensitive to short circuits and contact with metallic objects. Next, shrink the tubing with a hot airgun heated to 150 degrees Celsius and then allow it to cool.
After that, apply epoxy glue to the left end to seal one side of the tubing, then glue the electrode to the back of the PCB with tubing. Subsequently, seal the other end of the tubing. In this step, place the PCBs on a flat surface.
Use a solder paste dispenser with 0.6 millimeter needle and 60 PSI pressure to manually dispense less than 50 microliters of the soldering paste onto every metallic pad on the PCB. With a pair of anti-static tweezers, place all components on the top layer of the PCB. Assign the component position and the components to their numbers.
Use a PCB hot airgun station preset to 260 degrees Celsius to solder all components. Wait until all the solder paste melts. Put away the hot airgun and allow the board to cool to room temperature.
Next, the 12-volt power supply is connected to the wall and the USB connector is inserted to the PC.After that, open the PuTTY software. Select Serial as the connection type, then enter COMX as a serial line where X is the number of the COM Port of the device. If no other COM Port device was installed, this number will be one.
Enter 38, 400 as speed. Click Open. The charger transmitter device is now ready to be used.
In order to perform the implantation and visualization, insert an animal model dedicated endoscope with the implantable device grasped into a snare into the stomach. When in the stomach, release the device. After that, extract the endoscope.
Equip it with a dissection cap and then reinsert it to the stomach. In order to implant the device to submucosa, apply saline solution mixed with methylene blue into the submucosal layer using an injection therapy needle catheter. Make a horizontal incision to create an opening in the submucosa using an electrosurgical knife with a knob-shaped tip.
Insert an affixed cap into the newly created space and with the use of an electrosurgical knife, continue disrupting, dilating, and dissecting the submucosal layer to create a large enough pocket to insert the stimulation device. Grasp the device which is lying freely inside the stomach with correctly oriented electrodes with a grasper and navigate it into the submucosal pocket. After that, use two hemostatic clips to secure the device in place inside of the submucosal pocket.
Then pull out the endoscope. Put the Ovesco clip on the endoscope and reinsert it into the stomach. Orientate the endoscope towards the pocket, grasp both sides of the pocket and apply the Ovesco.
After that, check the correct placement of the Ovesco. After successful implantation, place the charger transmitter coil in proximity of the implanted device, then plug in the RTL2832 dongle in the PC.Run the HDSDR software and set the center frequency to 432 megahertz. Subsequently, select the LO frequency to 431.95 megahertz, then select the Tune frequency to 432.00 megahertz.
Select Bandwidth to 960, 000. Transmit a Manchester-coded sequence from the charger transmitter by pressing the R key in the PuTTY terminal and receive the OOK modulated reply from the implant shown in the main HDSDR window. Shown here is the top copper layer of the PCB.
The component names are indicated on the top layer. And here is the bottom copper layer of the PCB. The component names are on the bottom layer.
And this figure shows the composite picture of all PCB layers. Once mastered, this technique can be done in four hours for the implantable device manufacturing and one hour for device implantation and testing if performed properly. While attempting this procedure, it's important to verify all functions of the implantable device prior to implantation.
Following this procedure, other methods like further development of algorithm and data processing can be performed in order to answer additional questions like the efficiency of the method. After its development, this technique paved the way for researchers in the field of gastroenterology to explore third space in gastrointestinal tract. After watching this video, you should have a good understanding of how to perform an endoscopy implantation of autonomous gastric micronuerostimulator in submucosa.
Don't forget that working with soldering paste and electronics manufacturing including working with hot airgun can be hazardous and precautions such as gloves and safety glasses should always be worn while performing this procedure.
