A wireless sensor little sufficient to be implanted in the capillary of the human brain could assist clinicians assess the healing of aneurysms — bulges that can trigger death or severe injury if they break. The stretchable sensor, which runs without batteries, would be twisted around stents or diverters implanted to manage blood circulation in vessels impacted by the aneurysms.
To lower expenses and speed up production, fabrication of the stretchable sensing units utilizes aerosol jet 3D printing to develop conductive silver traces on elastomeric substrates. The 3D additive production method enables production of extremely little electronic functions in a single action, without utilizing conventional multi-step lithography procedures in a cleanroom. The gadget is thought to be the very first presentation of aerosol jet 3D printing to produce an implantable, stretchable noticing system for wireless tracking.
“The beauty of our sensor is that it can be seamlessly integrated onto existing medical stents or flow diverters that clinicians are already using to treat aneurysms,” stated Woon-Hong Yeo, an assistant teacher in Georgia Tech’s George W. Woodruff School of Mechanical Engineering and the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. “We could use it to measure an incoming blood flow to the aneurysm sac to determine how well the aneurysm is healing, and to alert doctors if blood flow changes.”
Placed utilizing a catheter system, the sensor would utilize inductive coupling of signals to enable wireless detection of biomimetic cerebral aneurysm hemodynamics. The research study was reported August 7 in the journal Advanced Science.
Keeping an eye on the development of cerebral aneurysms now needs duplicated angiogram imaging utilizing contrast products that can have hazardous negative effects. Since of the expense and prospective unfavorable results, usage of the imaging method need to be restricted. Nevertheless, a sensor put in a capillary could enable more regular assessments without the usage of imaging dyes.
“For patients who have had a procedure done, we would be able to tell if the aneurysm is occluding as it should without using any imaging tools,” Yeo stated. “We will be able to accurately measure blood flow to detect changes as small as 0.05 meters per second.”
The six-layer sensor is made from biocompatible polyimide, 2 different layers of a mesh pattern produced from silver nanoparticles, a dielectric and soft polymer-encapsulating product. The sensor would be twisted around the stent or circulation diverter, which need to be less than 2 or 3 millimeters in size to suit the capillary.
The sensor consists of a coil to get electro-magnetic energy transferred from another coil situated outside the body. Blood streaming through the implanted sensor alters its capacitance, which changes the signals travelling through the sensor on their method to a 3rd coil situated outside the body. In the lab, Yeo and his partners have actually determined capacitance modifications 6 centimeters far from a sensor implanted in meat to imitate brain tissue.
“The flow rate is correlated really well with the capacitance change that we can measure,” Yeo stated. “We have made the sensor very thin and deformable so it can respond to small changes in blood flow.”
Usage of the aerosol jet 3D printing method was important to producing the stretchable and versatile electronic devices needed for the sensor. The method utilizes a spray of aerosol particles to develop patterns, enabling narrower function sizes than standard inkjet printing.
“We can control the printing speed, the printing width, and the amount of material being jetted,” Yeo stated. “The parameters can be optimized for each material, and we can use materials that have a broad range of viscosities.”
Due to the fact that the sensor can be made in a single action without expensive cleanroom centers, it could be produced in greater volume at lower expense.
The next stage of the aneurysm sensor will have the ability to determine high blood pressure in the vessel in addition to the circulation rates. “We will be able to measure how pressure contributes to flow change,” Yeo discussed. “That would allow the device to be used for other applications, such as intracranial pressure measurements.”
Yeo’s research study group has actually likewise established a versatile and wearable health monitor able to supply ECG and other details. He states the success of the tracking method shows the capacity for wise and linked wireless soft electronic devices based upon nanomaterials, stretchable mechanics, and artificial intelligence algorithms.
“We are excited that people are now recognizing the potential of this technology,” Yeo included. “There are a lot of opportunities to integrate this sensing mechanism into ultrathin membranes that are implantable within the body.”
Assistance for this research study originated from the Korea Institute of Industrial Technology, and a seed grant from the Georgia Tech Institute for Electronic Devices and Nanotechnology. This work was carried out in part at the Institute for Electronic Devices and Nanotechnology, a member of the National Nanotechnology Coordinated Facilities, which is supported by the National Science Structure (Grant No. ECCS 1542174).