Real-time intraoperative visualization of myocardial circulation by augmented reality temperature display
2010 (English)In: Minimally invasive therapy and allied technologies, Informa Healthcare, 2010, 61-61 p.Conference paper, Abstract (Other academic)
Background: Intraoperative ischemia during coronary surgery may have severe consequences for the patient and may also pose a difﬁcult diagnostic problem to the surgeon. There is no clinically used direct method to evaluate the effect on the circulation of various therapeutic maneuvers to the heart. Augmented (mixed) reality using projection of color- coded infra-red (IR) images onto the imaged tissues in real time may give an intuitive representation of the tissue surface temperature and thus, information about myocardial perfusion on the surface of the organ itself.
Purpose: To demonstrate in animal experiments the feasibility of presenting IR tissue temperature images reﬂecting myocardial perfusion into the surgical ﬁeld with augmented reality.
Method: We have constructed a system consisting of an IR camera and a projector integrated in such a way that they have identical optical axes, solving the geometrical correspondence problem in an easy way. In 5 pigs (weight = 57.5 ± 7 kg), the thorax was opened by median sternotomy. After exposing the heart, an elastic vessel loop was placed around the middle of the left descending coronary artery. A 2 mm ultrasound probe was inserted distally around the LAD for ﬂow velocity measurements. Subsequent ischemia-reperfusion periods were induced using a ﬁxed protocol.
Results: The time course of an occlusion was clearly seen in quantitative curves as well as in color-coded temperature maps on the surface of the heart. The difference in surface temperature between the three areas more or less affected by the ischemia was also clearly demon- strated. During ischemia, the surface of the myocardium showed concentrically arranged zones of different temperatures (IR penumbra) potentially cor- responding to different degrees of severity of ischemia.
Conclusion: Surface temperature changes due to ischemia can be assessed quantitatively and visualized in situ during occlusion of a coronary artery and subsequent reperfusion of the myocardium. This method shows potential as a fast and simple way of following myocardial perfusion during surgery. The change of the extension of the penumbra zone is a potential monitoring device for the thera- pies used in the salvage or prevention of ischemia in experimental or clinical cardiac surgery and may introduce new practices in monitoring duringcardiac and vascular anesthesia.
Place, publisher, year, edition, pages
Informa Healthcare, 2010. 61-61 p.
, Minimally Invasive Therapy, ISSN 1364-5706 ; 19 Suppl 1
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-93659DOI: 10.3109/13645706.2010.500867OAI: oai:DiVA.org:liu-93659DiVA: diva2:625579
22nd International Conference of the Society for Medical Innovation and Technology (SMIT), 2-4 September 2010, Trondheim, Norway