Todd Mainprize at Sunnybrook Hospital has, for the first time, delivered chemotherapy directly to a brain tumor, by breaking through the blood-brain barrier using tightly focused ultrasound.
The patient’s bloodstream was infused with a chemotherapy drug, as well as microscopic bubbles, which are smaller than red blood cells and can pass freely through blood. MRI-guided, low intensity sound waves targeted blood vessels in the blood-brain barrier, near the tumor site. The ultrasound waves vibrated the microbubbles, loosening the tight cell junctions of the blood-brain barrier. The loosened junctions allowed the chemotherapy drug to flow past the barrier and deposit within the targeted tumor site.
This breakthrough could also lead to new treatments for brain diseases such as Parkinson’s and Alzheimer’s.
Click to view Sunnybrook Hospital video.
NEUROTECH SAN FRANCISCO – APRIIL 6, 2016 @ THE MISSION BAY CONFERENCE CENTER
Salk‘s Sreekanth Chalasani‘s “sonogenetics” technique uses ultrasound to stimulate individual brain cells. A nature paper describes the technology as tested on worms. The goal is noninvasive stimulation of specific cell types or individual neurons in humans, with out using implanted electrodes or fiber-optic cables.
Current optogenetics therapies rely on inserting light-sensitive channel proteins into neurons. When hit by the correct color of light, usually sent by a fiber-optic cable, the channels open, allowing ions to flood in.
The new technique relies on touch-sensitive “channel” proteins, which can be added to specific brain cells through genetic engineering. The channels open when hit by an ultrasonic pulse, allowing ions to flood into a neuron and cause it to turn on.
Click to view Salk Institute video.
University of Maryland researchers are using MRI-guided focused ultrasound on the globus pallidus to treat Parkinson’s symptoms. The ExAblate Neuro system was developed by Israel’s Insightec. The treatment is non-invasive, as it does not require a cut, but its ultrasound impacts a deep region of the brain, which is not with out risk.
Currently, drugs and (implanted) deep brain stimulation techniques treat tremor, rigidity and dyskinesia in Parkinson’s patients.
According to Professor Howard Eisenberg, this treatment could “help limit the life-altering side effects like dyskinesia to make the disease more manageable and less debilitating.”
During the 2-4 hour outpatient procedure, patients lie in an MRI scanner with a head-immobilizing frame fitted with a transducer helmet. Ultrasonic energy is targeted through the skull to the globus pallidus, and images acquired during the procedure give physicians a real-time map of the area being treated. Patients are fully awake and able to interact with the treatment team, allowing the physicians to monitor immediate effects and make necessary adjustments.
Butterfly Network‘s Jonathan Rothberg wants to make a “super-low-cost version of a $6 million (ultrasound) machine, to make it 1,000 times cheaper, 1,000 times faster, and a hundred times more precise.” This will depend on software and extensive AI image research to extract key features to automate diagnoses.
Butterfly’s patent applications describe compact, hand held ultrasound scanners that create 3D images in real time. Rothberg want to create a cheap system that can be used in the poorest nations.
Current ultrasound machines use piezoelectric crystals or ceramics to generate and receive sound waves. They are wired and attached with cables to a signal processing box. Butterfly wants to integrate ultrasound elements on a computer chip, cheaply produce them, and simplify the creation of the arrays needed to produce 3D images.
Ultrahaptics uses ultrasound waves to make one feel as if he/she is touching virtual objects and surfaces with bare hands.
It’s creator, a University of Bristol graduate student, claims that it improves upon touch-free interfaces such as Kinect and Leap Motion by reflecting air pressure waves off the hand to create different sensations for each fingertip.
Applications could include interacting with moving objects in virtual reality games, or improving navigation for the visually impaired by projecting the sensation of Braille letters onto fingers in midair.
University of North Carolina Professor Nancy Klauber-Demore has improved the resolution and tumor-detecting ability of ultrasound scans.
Combining ultrasound with a contrast agent composed of tiny bubbles that pair with an antibody that many cancer cells produce at higher levels than do normal cells, Klauber-Demore was able to visualize lesions created by angiosarcoma. By binding to the protein SFRP2, the contrast agent may help distinguish malignant from benign masses found on imaging. Since SFRP2 is expressed in many cancers – including breast, colon, pancreas, ovarian, and kidney tumors – the technique could potentially be useful for a broad range of cancer types. As the level of SFRP2 in tumors increases as tumors develop, the team will also investigate whether the technique can be used to track tumor growth.
Virginia Tech Carilion Research Institute scientists, led by Professor William Tyler, have demonstrated that ultrasound directed to a specific region of the brain can boost performance in sensory discrimination. This is the first example of low-intensity, transcranial-focused ultrasound modulating human brain activity to enhance perception.
The scientists delivered focused ultrasound to an area of the cerebral cortex that corresponds to processing sensory information received from the hand. To stimulate the median nerve, they placed an electrode on the wrist and recorded brain responses using EEG. Before stimulating the nerve, they began delivering ultrasound to the targeted brain region. The ultrasound decreased the EEG signal and weakened the brain waves responsible for encoding tactile stimulation.
Subjects were then given two neurological tests: the two-point discrimination test, which measures a one’s ability to distinguish whether two nearby objects touching the skin are truly two distinct points, rather than one; and the frequency discrimination task, which measures sensitivity to the frequency of a chain of air puffs. The subjects receiving ultrasound showed significant improvements in their ability to distinguish pins at closer distances and to discriminate small frequency differences between successive air puffs.
Navy sonar technology is being miniaturized by University at Buffalo professor Tommaso Melodia to be applied inside the human body to treat diseases like diabetes and heart failure in real time.
A network of wireless body sensors that use ultrasounds could be used to wirelessly share information between medical devices implanted in or worn by diabetic/heart failure patients.
Previously, researchers focused on linking sensors together via electromagnetic radio frequency waves – the same type used in cellular phones, GPS and wireless devices. Radio waves can be effective, but they generate heat and require large amounts of energy to propagate through skin, muscle and tissue. Ultrasound may be a more efficient way to share information as 65 percent of the body is composed of water. This suggests that medical devices, such as a pacemaker and a blood oxygen level monitor, could communicate more effectively via ultrasounds compared to radio waves.
Melodia highlights the technology’s use in diabetes patients, where wireless blood glucose sensors could be connected to implantable insulin pumps. The sensors would monitor the blood and, via the pumps, control the dosage of insulin as needed in real time.