ANNEX 3.4: Summary of System Technologies
Current technology for measuring blood pressure (i.e. oscillometric method) is extremely sensitive to movement and vibrations and therefore limited to situations where significant vibration or acoustic noise is not present. These situations make it virtually impossible to use current systems for blood pressure measurement aboard ambulances, helicopters or search and rescue operations. To counter the sensitivity of current BP systems to noise and vibrations, Dr. Stergiopoulos’ adaptive auscultatory method [J8, 1, P5-P7, P11] provides a novel device that effectively removes noise and vibration effects from the audible heartbeats (i.e. Korotkoff sounds).
Sponsors: Defence R&D Canada Thrust 6ca, Work Unit# 6ca19, NSERC Discovery Grant,
Commercial Product: The commercialization process for the above technology has been completed and the end result is the Non-Invasive Blood Pressure (NIBP) ambulatory product entitled Piesometer Mk-1 (http://www.canamet.com/piesometer_mk-1.html) , which is an Automated Blood Pressure (ABP) monitor for Stress Test ECG, Ambulances, and 24-hour ambulatory applications. It includes a Graphic User Interface and telemedicine functionality that allows verification of the ABP measurements (if needed) and for records to be transmitted over land or wireless phones. It addresses the market sectors for Stress Test ECG, Home Care, Ambulances, Cardiologists, and Primary Care Physicians. The Piesometer Mk-1 has achieved the necessary benchmarks, including FDA 510K (K041169) marketing clearance for the USA (Registration# 3004793673), the CSA/UL, CE marks, marketing clearance in Canada (Registration# 67375), Europe, China and the rest of the world. The Piesometer Mk-1 is motion and noise tolerant and includes functions for use in single and continuous measurement application, 24-hour ambulatory monitoring, and integration with Stress Test ECG systems (monitoring patients on a treadmill).
Sponsors: European Commission Grants #26764-New Roentgen, EC-IST-2000-28168 MRI-MARCB, Ontario Challenge Fund (ORDCF), NSERC CRD grant
Industrial Collaborator: CANAMET Inc., SIEMENS (Germany), PHILIPS (Germany)
Commercial Product: The commercialization process for the above technology has been completed and the end result (http://www.canamet.com/ct_cat.html) is a software package that can be integrated with single or multi-slice CT scanners. It upgrades the functions of a single-slice or low-end multi-slice CT scanner into a state-of-the-art multi-slice CT scanner. It has the equivalent cardiac and 3D imaging capabilities (necessary for the detection of coronary calcification, calcium scoring) as a high end multi-slice CT scanner at a fraction of the cost. Clinical testing for FDA-510K marketing clearance has not been initiated yet.
The present investigation aims to develop a signal processing structure for a non-invasive intracranial ultrasound system technology including signal processing techniques that monitor relative density fluctuations in the brain, which are directly related to intracranial pressure (ICP) changes, and provide diagnosis of traumatic brain injuries, hemorrhage and stroke. The proposed system concept differs fundamentally from other techniques in that it uses multi-frequency transmissions to identify the dispersive properties of the brain or contained fluids for classification and a relative phase estimation approach instead of time delay in monitoring density fluctuations while maintaining high sensitivity estimation. This approach is immune to the time delay (or phase) in estimates caused by changes in skull dimensions due to thermal effects and/or deformation that may be perceived as density fluctuations. To the best of our knowledge, there are no publications in experimental development of non-invasive diagnostic intracranial ultrasound technology, although there are numerous publications in Journals of Neurosurgery and Neurology addressing intracranial pathological cases.
Sponsors: Defence R&D Canada Thrust 6ca, Work Unit# 6ca19, NSERC Discovery Grant
Impact of the Work: The US Marines and the US Army Walter Reed Medical Research Center have expressed interest to collaborate and provide clinical assessment for the above technology.
3D imaging technology further enhances the value of imaging techniques such as CT, MRI and ultrasound. Although 3D CT and MRI are more widely used today, by 2006, 50% of the 3D imaging market will be dominated by 3D ultrasound systems. The present investigation provides a unique adaptive ultrasound 3D beamforming technology that will address the fundamental image resolution problems of current 3D ultrasound systems. This adaptive beamforming technology can be integrated into existing 2D ultrasound systems and it can form the basis for a complete stand-alone portable 3D ultrasound solution.
This investigation focuses on the definition of a next generation fully digital ultrasound system technology that includes the development of an advanced 3D adaptive-synthetic aperture beamfoming ultrasound signal processing structure with unique 3D ultrasound visualization technology and a computing architecture development as an embedded system for linear and planar phased array ultrasound probes.
3D adaptive beamforming is applicable in a variety of next generation system applications. Although in all the following applications the signal processing technology is conceptually identical, the differentiation between these systems is in their employed frequency regime that defines the application area and the array configuration in terms of sensor spacing and sensor technology.
- Wireless communication frequency regime for echo cancellation and signal distribution by directional antennas,
- Volumetric ultrasound frequency regime for medical imaging,
- Sonar high-frequency regime for 3D underwater camera for divers, mine hunting, underwater inspection,
- Acoustic frequency regime for 3D tomography visualization, non-destructive quality inspection of materials.
Therefore, the results of this investigation are applicable in all the above system applications. However, for practical, commercial and marketing rationale, our current project efforts had to focus at a particular system application; and this was chosen to be volumetric ultrasound medical imaging to assist medical diagnostic and non-destructive imaging system applications.
Sponsors: Defence R&D Canada TIF fund, European Commission EC-IST-1999-10618 MITTUG, EC-IST-2001-34088 ADUMS
Industrial Collaborator: CANAMET Inc., ESAOTE (Italy), ATMEL (Italy)
Impact of the Work: A portable 3D ultrasound prototype has been build and the imaging results are shown at the following web-site.
The UWB is not a mature technology and IEEE standards have not been established yet since there is a competing environment by the existing proprietary technologies of MOTOROLA and INTEL to dominate the wireless consumer market. However, the wide varieties of UWB applications, demonstrate the unstoppable trend in wireless communications and networking, which transits from licensed narrowband systems to unlicensed wideband systems. The mutual interference of co-located UWB transmissions must then be considered; and this defines the scope of this investigation in the UWB wireless communication technology. It is important to note also that the proposed concept of our UWB technology investigation was first defined and experimentally tested successfully at the Electromagnetic (EM) Chamber of the University of Toronto, on board the strong interference EMC field of a Black Hawk helicopter for MED-EVAC and in hospital environments, as part of a contract by the US-Marines for a feasibility study on UWB medical applications for MED-EVAC.
The processing for removing Narrow Band Interference (NBI), and Multiple Access Interference (MAI) is crucial for the commercial exploitation of Ultra Wideband (UWB) wireless communications technologies. Classical digital communication systems are designed for narrow band communications. When applied in wideband communications, the existing techniques leave the large degree of wideband freedom unexploited. We hereby present a method and apparatus of adaptive time-frequency-space interference cancellation for UWB wireless systems, which find an elegant balance between performance and implementation complexity.
This investigation borrows from the experience of our team from the 3D ultrasound adaptive beamforming of our European-Canadian project ADUMS, and the signal processing expertise in radar, sonar, and medical imaging systems [B1], where a rich set of techniques for (adaptive) wideband processing are available. It is, therefore, the objective of our current development to effectively cancel the NBI and MAI in UWB communications, by utilizing adaptive wide band signal processing techniques.
It is, yet, another objective of our current project to achieve an elegant balance between performance and implementation complexity, so as to enable real time processing.
It is, further, an objective of our current project to be a platform technology, which can give boosts to the anti-interference performance of diverse existing UWB communication techniques.
Sponsors: Grant support from US-Marines, IRAP grant
This investigation makes use of a microwave radiometry technique to provide temperature information at a depth of up to several centimeters in subcutaneous tissues. In particular, an apparatus for non-invasively measuring temperature distribution within a human body, including the human skull for brain intracranial diagnostic applications is presented. The novelty of the proposed methodology includes the deployment of an ellipsoidal cavity to achieve maximum peak of radiation pattern in order to measure the intensity of the microwave energy, radiated by the human brain or other internal vital organs of interest, by using two microwave total power radiometers and relevant non-contacting antennas within the range of 1-4GHz. In a sense, the ellipsoidal conductive wall cavity is actually operating as a three dimensional analog beamformer. This requires that the human skull is placed at one focal point of the ellipsoida cavity while a receiving microwave antenna is placed at the other focal point that will sense the convergence of the radiated thermal energy from the human brain in the microwave frequency regime.
The basis of the theoretical analysis of this work is the fundamental law of the chaotic radiation emerging from material objects (i.e. microwave electromagnetic thermal noise). Green’s function theory is used for the estimation of the electric field measured and the qualitative explanation of the radiometric data acquired. The numerical results of a 2 Dimensional Finite Difference Time Domain code constitute a quantitative complementary to the theoretical analysis. In this investigation, the developed prototype system and its modules are fully described, as well as the results from phantom and animal experiments.
Sponsors: Defence R&D Canada Thrust 6ca, Work Unit# 6ca19