Untethered Microgrippers Sample Biologic Tissue
By HospiMedica International staff writers Posted on 13 May 2013 |
Image: A single μ-gripper next to a catheter (Photo courtesy of Johns Hopkins University).
A new study describes thermally activated microgrippers that can reach narrow conduits in the body and be used to excise tissue for diagnostic analyses and biopsies.
Researchers at Johns Hopkins University (JHU; Baltimore, MD, USA) designed the submillimeter endoscopic microgrippers (μ-grippers) to resemble biological appendages, such as hands, with rigid phalanges and flexible joints. The residual stress powered actuators allow them to close and grasp without the need for tethers, while the rigid phalanges of the μ-grippers are composed of nickel, and hence, respond to an applied magnetic field. A thermo-sensitive polymer trigger layer on the joints keeps the μ-grippers flat at 4 °C, but softens at 37 °C, causing the μ-grippers to close.
The μ-grippers are small enough that hundreds can be deployed at a time and actuated en masse, and could therefore form the basis for a more statistically efficient means to screen large surface area organs such as the colon. To test the feasibility of biologic tissue sampling with μ-grippers, the researchers used a swine colon in ex vivo studies. They uniformly spread hundreds of μ-grippers by rotating the endoscope during the deployment. The arms of each millimeter-long μ-gripper is composed of chromium and gold actuators that naturally want to bend inwards, but are held back by the thin layer of polymer coating.
To simulate the normal human temperature, the colon was submerged in a water bath kept at 37 °C, whereupon the coating dissolved and the talons snatched up cells at close proximity; the researchers then visually verified the closure of the μ-grippers using endoscopic imaging. After closure, the vast majority of μ-grippers were retrieved using a magnetic catheter inserted through the endoscope. The researchers found that the μ-grippers identified the lesion 45% of the time; when the swarm was boosted up to 1,500 μ-grippers, the efficiency rose to 95%. The study was published in the April 2013 issue of Gastroenterology.
“Our results suggest a new paradigm in medicine whereby large numbers of small, tether-free microsurgical tools could complement individual, large, tethered biopsying devices,” concluded lead author Evin Gultepe, PhD, and colleagues of the department of chemical and biomolecular engineering. “The tissue retrieved by the μ-grippers is of sufficient quality and quantity to allow DNA and RNA extraction, as well as polymerase chain reaction (PCR) amplification in an effort to look for previously identified disease-diagnostic markers.”
Related Links:
Johns Hopkins University
Researchers at Johns Hopkins University (JHU; Baltimore, MD, USA) designed the submillimeter endoscopic microgrippers (μ-grippers) to resemble biological appendages, such as hands, with rigid phalanges and flexible joints. The residual stress powered actuators allow them to close and grasp without the need for tethers, while the rigid phalanges of the μ-grippers are composed of nickel, and hence, respond to an applied magnetic field. A thermo-sensitive polymer trigger layer on the joints keeps the μ-grippers flat at 4 °C, but softens at 37 °C, causing the μ-grippers to close.
The μ-grippers are small enough that hundreds can be deployed at a time and actuated en masse, and could therefore form the basis for a more statistically efficient means to screen large surface area organs such as the colon. To test the feasibility of biologic tissue sampling with μ-grippers, the researchers used a swine colon in ex vivo studies. They uniformly spread hundreds of μ-grippers by rotating the endoscope during the deployment. The arms of each millimeter-long μ-gripper is composed of chromium and gold actuators that naturally want to bend inwards, but are held back by the thin layer of polymer coating.
To simulate the normal human temperature, the colon was submerged in a water bath kept at 37 °C, whereupon the coating dissolved and the talons snatched up cells at close proximity; the researchers then visually verified the closure of the μ-grippers using endoscopic imaging. After closure, the vast majority of μ-grippers were retrieved using a magnetic catheter inserted through the endoscope. The researchers found that the μ-grippers identified the lesion 45% of the time; when the swarm was boosted up to 1,500 μ-grippers, the efficiency rose to 95%. The study was published in the April 2013 issue of Gastroenterology.
“Our results suggest a new paradigm in medicine whereby large numbers of small, tether-free microsurgical tools could complement individual, large, tethered biopsying devices,” concluded lead author Evin Gultepe, PhD, and colleagues of the department of chemical and biomolecular engineering. “The tissue retrieved by the μ-grippers is of sufficient quality and quantity to allow DNA and RNA extraction, as well as polymerase chain reaction (PCR) amplification in an effort to look for previously identified disease-diagnostic markers.”
Related Links:
Johns Hopkins University
Latest Surgical Techniques News
- Miniaturized Ultrasonic Scalpel Enables Faster and Safer Robotic-Assisted Surgery
- AI Assisted Reading Tool for Small Bowel Video Capsule Endoscopy Detects More Lesions
- First-Ever Contact Force Pulsed Field Ablation System to Transform Treatment of Ventricular Arrhythmias
- Caterpillar Robot with Built-In Steering System Crawls Easily Through Loops and Bends
- Tiny Wraparound Electronic Implants to Revolutionize Treatment of Spinal Cord Injuries
- Small, Implantable Cardiac Pump to Help Children Awaiting Heart Transplant
- Gastrointestinal Imaging Capsule a Game-Changer in Esophagus Surveillance and Treatment
- World’s Smallest Laser Probe for Brain Procedures Facilitates Ablation of Full Range of Targets
- Artificial Intelligence Broadens Diagnostic Abilities of Conventional Coronary Angiography
- AI-Powered Surgical Visualization Tool Supports Surgeons' Visual Recognition in Real Time
- Cutting-Edge Robotic Bronchial Endoscopic System Provides Prompt Intervention during Emergencies
- Handheld Device for Fluorescence-Guided Surgery a Game Changer for Removal of High-Grade Glioma Brain Tumors
- Porous Gel Sponge Facilitates Rapid Hemostasis and Wound Healing
- Novel Rigid Endoscope System Enables Deep Tissue Imaging During Surgery
- Robotic Nerve ‘Cuffs’ Could Treat Various Neurological Conditions
- Flexible Microdisplay Visualizes Brain Activity in Real-Time To Guide Neurosurgeons