Short Description
OFF is an optical (visible light) camera system that is connected to a a fluoroscopy machine, in such a way that the optical images allow the user to anticipate and align the medical image prior to using radiation. The system can also be used to preset collimation, watch for patient events like urination and ingestion, and even follow a moving patient. The primary envisioned use is with fluoroscopy; however, patent protection has also been sought on other modalities.
The Prototype
The prototype was built for fluoroscopy and was used in a feasibility study at El Paso Children's Hospital.
The prototype consists of:
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Two optical video cameras
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Connected to the fluoroscopy machine and wired to a separate monitor.
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Calibrated to show the centrality of the expected fluoroscopy image.
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One camera shows the patient’s left to right position marking centrality.
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One camera shows the patient’s cranial to caudad position marking centrality.
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Single two-view monitor
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Attached to the imaging intensifier allowing easy visualization by the fluoroscopist.
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Markings on both views showing centrality.
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Power supply to the cameras and monitor
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Waterproof and shock-resistant for patient and operator safety.
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The image shows two cameras. One at the caudad aspect of the imaging intensifier and another to the patient’s left just below the imaging intensifier. The monitor is attached just above the control panel.
The monitor shows both camera views. The left image shows the patient’s position (head to foot) with a target marking the center of the expected fluoroscopy image. The right image shows the patient’s position left to right with a target marking the center of the expected fluoroscopy image.
How the Device is Used
These two animations compare aligning the patient for fluoroscopy with the device and without the device.
Traditionally, the fluoroscopist uses radiation to center over the region of interest. Essentially fluoroscopy is used to align the fluorscopic images. This creates non-diagnostic dose. This is the current standard method of aligning patients under fluoroscopy. It has been termed "fluoro-hunting" in the scientific literature.
With OFF, the fluoroscopist uses optical video to center over the region of interest which reduces the required fluoroscopy time and thus dose to the patient. No non-diagnostic dose is needed to align the image.
This is a short video of me summarizing the traditional fluorosocpy technique and how it differs from the technique used with OFF.
This is a short video of me using the prototype. The patient is a mannequin with a heart-shaped pin over the chest. I maneuver the image intensifier to center over the heart while using the optical imaging device for guidance. Once aligned, I then use fluoroscopy.
Results/Benefits
Results from Using the Prototype
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Use of the optical imaging prototype resulted in >80% dose reduction on pediatric fluoroscopy exams.
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Parents reported increased confidence that the radiologist was monitoring the child during the exam.
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Physicians in training reported an improved learning curve in developing fluoroscopic skill.
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Accelerated technologist-radiologist communication regarding patient positioning.
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Improvement in fluoroscopy timing when visualization of contrast ingestion or urination was desired.
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Tighter monitoring of and adjustment for patient movement.
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Overall decreased fluoroscopy exam times allowing larger patient turnover in the fluoroscopy suite.
Potential Improvements Upon the Prototype
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Ideally the device will be integrated into fluoroscopy machines or manufactured as part of new fluoroscopy systems.
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An integrated device could allow for visualization of the expected collimation on the monitor which would further reduce dose.
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Integration will also decrease the footprint of the device and secure permanent calibration with the fluoroscopic image.