NHLBI SBIR/STTR Contract Topic

069 Wireless Physiologic Telemetry for Interventional MRI

(Fast-Track proposals will be accepted)

Number of anticipated awards: 1

Background

Magnetic resonance imaging (MRI) has potential to revolutionize minimally invasive surgery and interventional procedures by affording improved tissue visualization without conventional surgical incisions. Many such procedures will be conducted under both X-ray and MRI guidance. Such procedures require high fidelity hemodynamic recording of physiological signals such as electrocardiography and invasive blood pressure, with seamless bidirectional transfer between X-ray and MRI. To date there are no suitable commercial solutions.

A wireless telemetry system would allow acquisition of hemodynamic signals (multichannel electrocardiography, invasive blood pressure, noninvasive hemoglobin saturation, temperature, etc.) safely in both the MRI and X-ray fluoroscopy environments, and allow continuous monitoring during transportation between the two.

Specifications

The system must conform to the following specifications:

• The system must operate safely at MRI field strengths of 1.0T to 3.0T. • The system must record and transmit signals with the patient inside the magnet bore during imaging.
• The system should filter MRI-specific noise (e.g. radiofrequency pulses and gradient switching) and be robust to a range of rapid pulse sequences with continuous duty cycle, including single and multi-slice real-time, three-dimensional gradient echo, balanced steady state free precession, and (non-real-time) turbo spin echo techniques. The system must be able to filter noise from low frequency events, such as spoiler gradients or magnetization preparation sequences.
• The system should provide ten electrodes for diagnostic electrograms (four limb, six chest) under an X- ray environment and at least six (four limb, two chest) under an MRI environment. The electrode and lead system should be safe for operation under MRI, resistant to inadvertent loop formation, and should be radiolucent for operation under X-ray.
• The system should allow transduction of two simultaneous channels of invasive blood pressure from fluid- filled catheters, ideally with commonly used clinical invasive blood pressure transducers.
• The system should measure continuous noninvasive hemoglobin oxygen saturation.
• All physiological signals should be aggregated in a single unit for wireless telemetry. Signals must be received in at least one base station in each modality, (one in X-ray and another in MRI), with automatic handoff from one to the other. Base stations should connect to popular commercial hemodynamic recording systems (specifically Siemens Sensis and General Electric MacLab).
• The system should provide for uninterrupted operation for at least 6 hours.
• The system should NOT generate radiofrequency noise that interferes with MRI. The system should not interfere with common commercial Bluetooth and other common radiofrequency patient physiologic telemetry systems used during MRI.

Proposals to address electrocardiogram artifacts from magnetohydrodynamic effects are welcomed but not required.

The sponsoring NIH laboratory is willing to provide access to acquired physiological signals without preprocessing; alternatively the offeror should have access to such a laboratory independently for development and for testing.

Deliverables

The Phase I deliverable is a working prototype to support investigational X-ray and MRI guided interventional procedures in patients. This includes ten ECG leads for use in X-ray and at least six ECG leads for use in MRI, two invasive pressure transducers, and hemoglobin saturation.

The Phase II deliverable is a commercial-grade clinical system.

For more information, see the FY2012 Contract Solicitation or contact OTAC.

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Last Updated December 2011