(63 Total References)
Faculty Members | Department of Anesthesia
JOSEPH A. ...
JOSEPH A. FISHER
Dr. Fisher is a co-founder of Thornhill Research and Professor in the faculty of Medicine at the University of Toronto.
He is currently a Staff Anaesthetist at the University Health Network and Senior Scientist, Human Physiology & Clinical Investigation, at Toronto General Research Institute.
has published over 120 papers in peer-reviewed journals, and designed and consulted on products for NASA
, Government of Canada, United States Marine Corps
, and various companies.
He is an inventor on over 25 issued and pending patents, including the core technology behind Thornhill's technologies.
Click here to search Pubmed for Dr. Fisher's research
or here for Dr. Fisher's
Steve Iscoe, a collaborator of Dr Fisher since 1994, was a founding shareholder and president of one of the companies that became Thornhill Scientific.
Dr. Joe Fisher, Q-Collar ...
Dr. Joe Fisher, Q-Collar Co-Inventor
Staff Anesthesiologist, University Health Network
Professor, Faculty of Medicine, University of Toronto
Department of ...
Department of Anesthesia
Over the last 15 years Dr. Fisher's
laboratory has developed the theory and technology for control of blood gases in spontaneously breathing and ventilated subjects.
This work has facilitated a number of scientific and clinical advances.
First, using controlled changes of carbon dioxide and oxygen, plus MRI imaging, his
team developed unique functional images of cerebral blood flow, or cerebrovascular reactivity.
They also developed new image processing methods, which in turn let to new understandings of how brain blood flow is controlled, and has enabled the evaluation of the risk of stroke and the effectiveness of brain vascular bypass surgery in patients with cerebrovascular disease.
Second, Dr. Fisher's
research team applied blood gas control to develop a novel fully automated respiratory Fick measure of cardiac output.
They believe this is the most accurate known method of measuring cardiac output (see Klein et al. BJA 2015; PMID 25488304).
Third, they have developed methods to accelerate the respiratory elimination of hydrocarbons such as anesthetics and carbon monoxide, without affecting the carbon dioxide levels.
Finally, they developed the world's first digitally controlled anesthetic delivery system, and applied it for the first time in patients, at the UHN.
For the last decade Dr. Fisher has been the Chief Scientist at Thornhill Research Inc., a spin-off company from UHN.
has developed a compact rugged life-support system for treating and transporting critically injured personnel in war and disaster conditions.
In addition, he
developed the world's first FDA
approved clinical digital in-line vaporizer for the administration of anesthetics.
Publications and Awards
View PubMed search of this faculty member's recent publications
Duffin, J., Sobczyk, O., Crawley, A. P., Poublanc, J., Mikulis, D. J., & Fisher
, J. A. (2015).
The dynamics of cerebrovascular reactivity shown with transfer function analysis.
Klein, M., Minkovich, L., Machina, M., Selzner, M., Spetzler, V. N., Knaak, J. M., . . . Fisher
, J. A. (2015).
Non-invasive measurement of cardiac output using an iterative, respiration-based method.
Br J Anaesth, 114(3), 406-413. doi:10.1093/bja/aeu377
Poublanc, J., Crawley, A. P., Sobczyk, O., Montandon, G., Sam, K., Mandell, D. M., . . . Fisher
, J. A. (2015).
Measuring cerebrovascular reactivity: the dynamic response to a step hypercapnic stimulus.
J Cereb Blood Flow Metab. doi:10.1038/jcbfm.2015.114
Sobczyk, O., Battisti-Charbonney, A., Fierstra, J., Mandell, D. M., Poublanc, J., Crawley, A. P., . . . Fisher
, J. A. (2014).
A conceptual model for CO-induced redistribution of cerebral blood flow with experimental confirmation using BOLD MRI.
doi:S1053-8119(14)00081-0 [pii];10.1016/j.neuroimage.2014.01.051 [doi]
Sobczyk, O., Battisti-Charbonney, A., Poublanc, J., Crawley, A. P., Sam, K., Fierstra, J., . . . Fisher
, J. A. (2015).
Assessing cerebrovascular reactivity abnormality by comparison to a reference atlas.
J Cereb Blood Flow Metab, 35(2), 213-220. doi:10.1038/jcbfm.2014.184
Dr. Smith approached Joe ...
Dr. Smith approached Joe Fisher, MD, anesthesiology professor at the University of Toronto, anesthesiologist at University Health Network and the chief science officer at Thornhill Research Inc., in Toronto, about ways to reduce the ability of the brain to slosh inside the skull.
Then Dr. Fisher
realized they could achieve the same effect by decreasing the blood outflow from the cranium, which would reduce compliance but not increase intracranial pressure.
Based on his
work in neuroanesthesia and lumbar puncture procedures, Dr. Fisher
knew firsthand about the effect of compression of internal jugular veins on CSF pressure.
"During those procedures, I'd ask my nurse to put a hand under the drapes and press on the patient's neck," he
In addition, the research team had hoped for a 5% to 10% reduction in damage related to the collar, but instead found an 85% reduction, Dr. Fisher
They published the findings in Neurosurgery (2012;70:740-746).
A second study in the Journal of Neurosurgery
(2012;117:1110-1118) reexamined and restained the samples for other biomarkers of brain injury.
This resulted in a 48% to 59% reduction in degenerative neurons and a 36% to 45% decrease in reactive astrocytes.
Furthermore, they saw a 44% to 65% reduction in microglial activation.
"We couldn't believe it," Dr. Fisher
and Bailes have conducted since 2012.