Current Projects of the Low-Frequency Instrumentation Laboratory:

Project Name: The Eso-Pill™: A Non-Invasive MEMS Capsule for Bolus Transit Monitoring in the Esophagus.

Lead by: Dr. M. Mintchev and Dr. K. Kaler

Conducted by: Mr. Ray Jui

Description:

Monitoring bolus transit in the esophagus has been pivotal for the diagnosis of achalasia, diffuse spasm, motor abnormalities associated with systemic disorders, and gastro-esophageal reflux disease. Despite recent advances in X-Ray imaging and the introduction of multichannel intraluminal impedancometry, these studies remain moderately invasive. Barium radiography subjects the patient to X-Ray radiation, while the new technique of impedance monitoring employs catheters introduced either transnasally or transorally. Rapid developments in microelectronics, micro-electromechanical systems (MEMS) and wireless radio-frequency (RF) transmission created the possibility of suggesting a conceptually different and completely non-invasive technique for esophageal bolus transit testing. In the present study, the concept of the ESO-Pill ™ is introduced, a non-invasive swallowable “smart” microelectronic capsule, which can monitor in real time its acceleration, velocity of propagation, position, and the contractile force that pushes it as it passes through the esophagus. The capabilities and the limitations of the ESO-Pill ™ are discussed in the context of the radically different type of measurements that such device could offer, while every attempt is made to associate these measurements with the presently available bolus transit monitoring standards in esophageal testing.

Sponsored by: Natural Science and Engineering Research Council of Canada.

Project Name: Correction of susceptibility difference artifacts due to the
presence of metallic implants in magnetic resonance images

Lead by: Dr. M. Mintchev and Dr M. Smith

Conducted by: Mr. Yves Pauchard

Description:

Geometric and intensity distortions arise in the presence of metallic implants in magnetic resonance imaging often precluding meaningful interpretation of acquired patient images. The presented method uses a point-based thin-plate spline image registration algorithm to calculate the necessary correction function to account for the geometric and intensity distortions. The reference image (without distortion) is obtained by imaging a specially designed three-dimensional (3D) grid phantom. The corresponding test image (containing the distortion) is acquired with the same imaging parameters, after positioning a specific metallic implant in the grid phantom. The algorithm able to align the test image with the reference image can describe the implant distortions and can therefore be used to correct any image containing the same distortions. Additionally, the test image is used to automatically identify 3 areas: (1) the non-recoverable area; (2) the distorted but recoverable area; and (3) the unaffected area. Image information in the non-recoverable area is removed for further evaluation, whereas the distorted but recoverable area is corrected.

Sponsored by: Natural Science and Engineering Research Council of Canada and the University of Calgary.

Project Name: Evaluating the dynamics of EGG and GEA signals using the Chaos Theory.

Lead by: Dr. M. P. Mintchev and Dr. D. Westwick

Conducted by: Mr. Charles Newton Price

Description:

A study of the external factors affecting the recordings of EGG/GEA signals through the quantitative assessment of the number of embedding dimensions; calculation of Recurrence Quantification Analysis (RQA) parameters to detect electrical uncoupling on EGG/GEA signals; use of the False Nearest Neighbour (FNN) dynamics to facilitate classification of deterministic, chaotic and random model signals, and to re-state chaotic nature of EGG/GEA signals.

Sponsored by: Natural Science and Engineering Research Council of Canada.

Project Name: Integrated Esophageal Pressure, pH and Bolus transit sensor.

Lead by: Dr. M. Mintchev and Dr. K. Kaler

Conducted by: Mr. Jose Luis Gonzalez Guillaumin

Description:

The last comprehensive statistics provided by the National Institutes of Health suggests that esophageal motility disorders (e.g. gastro-esophageal reflux, achalasia, dysphagia and diffuse spasm) affect about 10% of the population. Integrated catheters for combined monitoring of all variables of interest for comprehensive esophageal motility studies are still lacking. A catheter probe that integrates novel techniques for monitoring all variables of interest for esophageal motility studies is been developed.

Sponsored by: Natural Sciences and Engineering Research Council of Canada and the Gastrointestinal Motility Laboratory (Edmonton);

Project Name: Implantable, Transcutaneously Powered Neurostimulator System to Restore Gastrointestinal Motility.

Lead by: Dr. M. Mintchev

Conducted by: Mr. Denis Onen

Description:

Background: Neural electrical stimulation has been applied to restore the functionality of impaired gastrointestinal organs from disorders such as chronic constipation and gastroparesis. However, no substantial progress has been made until microprocessor-controlled movement of gastrointestinal content using sequential electrical stimulation was reported (by this laboratory). Although a portable version of a microprocessor-based neurostimulator has been successfully utilized in acute and chronic animal studies, an implantable version of the device is not yet available.
Aims: This study aims at investigating an optimal design solution for an implantable transcutaneously-powered gastrointestinal neurostimulator system. The ultimate goal of this project is to ensure that the implantable, transcutaneously-powered stimulator can be efficiently utilized in chronic animal and human experiments.
Methods: A software tool that models transcutaneously delivered power was used to analyze the best- and worst-case load voltages delivered to the implant under variable physical orientations of the transmitting and receiving coils. These variable orientations include: separation distance, axial misalignment, and angular misalignment. An analysis was performed to compare the power consumption of the system controller when using a Complex Programmable Logic Device (CPLD) to an implantable microprocessor-based solution in various voltage regulation scenarios. An analysis was also performed to estimate and optimize the power consumption of other critical parts of the implantable circuitry, including the receiving coil, the full-wave bridge rectifier; and the analog and digital circuitry. A prototype is being built to verify the results of the analysis and to provide the opportunity to test the neurostimulator in vivo.

Sponsored by: Natural Sciences and Engineering Research Council of Canada and the Department of ECE

Project Name: Wavelet Analysis in a Model of Gastric Electrical Uncoupling

Lead by: Dr. M. Mintchev and Dr. V. Dimitrov

Conducted by: Mr. Renato Cintra

Description:

Pending...

Sponsored by: National Council for Scientific and Technological Development - CNPq

Project Name: Implantable Multi-Channel Stimulator for Recreation of Impaired Gastrointestinal Motility.

Lead by: Dr. M. Mintchev and Dr. G. Jullien

Conducted by: Mr. Ehsan Jalilian

Description:

The purpose of this project is to develop an implantable gastrointestinal stimulator that can accelerate or decelerate gastric and colonic emptying. Four subserosally-implanted electrode sets are positioned longitudinally (in the case of colonic stimulation) or circumferentially (for gastric stimulation) along the axes of the organs. The stimulator induces artificial peristalsis by delivering
multi-channel overlapping electrical pulses to the organs.

Using a microprocessor and a wireless module allows reprogramming the stimulation parameters (such as the length of a stimulation session or the voltage amplitude of the stimulating pulses) and provides ease of use for patient trials.

Sponsored by: Natural Sciences and Engineering Research Council of Canada

Project Name: Electronic Mosquito: A Semi-Invasive MEMS for Blood Sampling and Analysis

Lead by: Dr. M. Mintchev and Dr. K. Kaler

Conducted by: Mr. Giorgio Gattiker

Description:

For many years reliable blood sampling has been the main problem precluding the development of real-time systems for blood analysis and subsequent closed-loop physiological function control. While the analysis of a static blood sample in laboratory conditions has been rapidly advancing in reliability and blood volume reduction, non-invasive real-time blood analysis performed in vivo (while the blood is circulating in the body) has been elusive and unreliable.

At a miniature scale the proposed system does penetrate the skin to extract a static blood sample for further analysis, but the extent of this penetration, and particularly the fact that it can be made painless, is particularly attractive for such applications as automated glucose analysis for closed-loop control of insulin infusion (artificial pancreas), continuous drug monitoring, or even periodic DNA analysis for security and identification purposes. The major building blocks of the proposed microelectromechanical system consist of (1) MEMS-based microactuator; (2) microneedle, integrated with the actuator; (3) microsensor (blood analysis); (4) microelectronics (signal amplification and conditioning, analog-to-digital conversion and wireless data transfer); (5) power supply module; and (6) associated matrix packaging. An array of single-use e-mosquitoes forms a disposable patch attachable to the body via an adhesive antiseptic layer. The devices in the patch are individually actuated and have an area of approximately 5mm2. A matrix of 180 e-mosquitoes implemented on a 3cm x 3cm patch could therefore provide periodic blood sampling for more than 1 week, even if blood monitoring is required every hour.

Sponsored by: Canadian Microelectronic Corporation and Natural Sciences and Engineering Research Council of Canada

Project Name: Transcutaneous power and data telemetry for an implantable gastrointestinal stimulation system.

Lead by: Dr. M. Mintchev and Dr. G. Jullien

Conducted by: Mr. James Doherty

Description:

The purpose of this research is to investigate the use of a transcutaneous inductive coupling for transferring power and data to an implanted gastrointestinal stimulation system. Two distinct implementations are being investigated. The first involves transcutaneous power transfer to a single multi-channel implanted device with bi-directional data telemetry, while the second involves transcutaneous power transfer to multiple single-channel implanted microstimulators with integrated downlink. In order to expedite the design process, a software tool was developed to explore link behaviour under suboptimal coupling conditions. Bench testing of both implementations is ongoing.

Sponsored by: iCORE and the Alberta Ingenuity Fund

Project Name: Wavelet Analysis in a Model of Gastric Electrical Uncoupling

Lead by: Dr. M. Mintchev and Dr. V. Dimitrov

Conducted by: Mr. Ilian Tchervensky

Description:

Abnormal gastric motility function could be related to gastric electrical uncoupling, the lack of electrical, and respectively mechanical, synchronization in different regions of the stomach. Therefore, non-invasive detection of the onset of gastric electrical uncoupling can be important for diagnosing associated gastric motility disorders. The aim of the study is to provide a wavelet-based analysis of electrogastrograms (EGG, the cutaneous recordings of gastric electrical activity), to detect gastric electrical uncoupling.

Sponsored by: : Natural Science and Engineering Research Council of Canada

Project Name: Improved Measurement-While-Drilling and Directional Horizontal Navigation Utilizing Gyroscope-Based Inertial Navigation Systems

Lead by: Dr. M. Mintchev

Conducted by: Mr. Efraim Pecht, Mr. Justin Cloutier

Description:

Contemporary surveying in Measurement-While-Drilling (MWD) processes incorporates measurements from three-axes accelerometers and magnetometers. Unfortunately, magnetometer-related problems limit the navigational capabilities of this technique. The introduction of a fiber optic gyroscope (FOG) based inertial navigation systems (INS) in MWD aims at overcoming these limitations. However, drifts in the measurements provided by the INS might be prohibitive for the long-term utilization of this modern navigational method downhole. The purpose of this project is to search for methods that can improve the INS performance in MWD processes and particularly during the horizontal drilling phase. One of the methods being evaluated is the implementation of the In-Drilling Alignment (IDA). The IDA is employed to excite in a controllable fashion latent states and increase the  observability of the entire INS. Theoretical and experimental work is ongoing.

Sponsored by: : Natural Science and Engineering Research Council of Canada

Other On-going Work:

1. Real-time data acquisition and monitoring of low frequency signals;
2. Real-time signal conditioning and processing;
3. Development of infralow frequency electronic amplifiers;
4. Real-time 3-D modelling of internal organs for the purpose of functional stimulation;
5. Extraction of quantitative information from human electrogastrograms;
6. Development of biomedical force and pressure sensors;
7. Real-time azimuth monitoring using fiber-optic gyroscopes;
8. Non-linear adaptive compensation in non-ideal noise environments;
9. Methods for reduction of susceptibility artifacts in MR imaging;
10. Design and implementation of real-time functional stimulation systems for internal organs;
11. Design and implementation of multichannel systems for gastrointestinal motility measurements;
12. Modelling of fiberoptic gyroscopes for instrumentation applications;
13. Real-time monitoring of the direction in horizontal drilling processes for the oil industry;
14. Fiberoptic gyroscope-based Measurement-While-Drilling processes for the oil industry;
15. Emission estimation and emission control for stationary internal combustion engines;
16. Sensor validation systems for stationary internal combustion engines;
17. Neural network applications in low frequency instrumentation systems.
18. Tele-medical applications.