(236 days)
The Varian RPM Respiratory Gating device is an attachment to the radiation therapy simulator and Varian Clinac radiation therapy treatment system. It is to be used to characterize (in simulation) the patient's respiratory patterns and then, in treatment, to trigger beam-hold and limit the beam-on time to those points in the respiratory cycle where the target volume is within acceptable motion limits.
The video-based RPM Respiratory Gating System provides a respiration gating signal to a Clinac radiation therapy machine to "hold" the beam during planned intervals of the respiration cycle. The system derives beam-hold signals from the patient chest motion, which it tracks using a video camera connected to a PC workstation. The computer includes real-time and multi-channel video digitization and display hardware controlled by digital image analysis and video tracking software that runs as a Windows NT application. The PC also includes a relay and I/O board that under software control opens and closes the Clinac gating switch for beam-hold control. The RPM Respiratory Gating System receives live video images from a monochrome CCD video camera equipped with an infrared ring illuminator. When used for planning, the RPM Respiratory Gating System receives images from both the camera and a simulator or fluoroscope. For treatment use, the RPM Respiratory Gating System receives images from the camera.
The provided text describes the RPM Respiratory Gating System and compares its characteristics to a predicate device, the NIMS Respitrace System. However, it does not include specific acceptance criteria, a study proving device performance against those criteria, or details regarding sample sizes, expert involvement, or ground truth establishment for such a study.
Therefore, many of the requested sections will be marked as "Not provided in the text."
Here's the breakdown of the information extracted from the provided text:
1. Table of Acceptance Criteria and Reported Device Performance
Acceptance Criteria: Not provided in the text.
Reported Device Performance: The text provides a comparison of technical specifications between the RPM Respiratory Gating System and the predicate device. These specifications, while indicative of performance, are not explicitly framed as "acceptance criteria" against which the device's performance was measured in a study.
| Characteristic/Specification | RPM Respiratory Gating System Performance (as reported) | Predicate Device (Respitrace) Performance (for comparison) | Comments (from text) |
|---|---|---|---|
| Objects physically attached to patient | Light foam block with retro-reflective marker on it attached to upper abdomen area | Respiband inductive coil ribbon wrapped around the patient stomach or rib cage | |
| Wire connections made to patient | None | Wires connecting Respiband to the computer and control box | |
| Measured parameter | Vertical position of the marker attached to abdomen in video camera field of view | Respitrace output voltage is a measure of inductance of Respiband coil wrapped around the abdomen or rib cage. Inductance varies with the length of the coil, which in turn varies with circumference of the band wrapped around the body. | RPM Respiratory Gating System responds to the motion of the whole body as well as respiratory motion, while Respitrace responds to motion only due to abdomen or rib cage size change. |
| Maximum signal range | 0 to 479 (row position in vertical field of view of video image) for NTSC video camera. | -5V to +5V | RPM Respiratory Gating System vertical camera field of view varies as a function of camera-marker block distance. For the RPM Respiratory Gating System optics the vertical FOV as a function of distance is: V-FOV = 0.12 * Distance. For example at 250-cm distance the V-FOV is 30 cm. |
| Measurement resolution | 0.1 pixels standard deviation | 1 mV | The RPM Respiratory Gating System resolution is equivalent to 1 / 4800 of V-FOV. This translates to $0.1 * 30 / 480 =$ 0.00625 cm, or 0.0625 mm at 250 cm distance. |
| Measurement drift | None | 10 mV per second | |
| Sampling rate | 30 Hz | 200 samples/sec for A/D converter. The Respitrace output signal bandwidth is 25 Hz. | |
| Distance to patient | 15 Ft Maximum patient-camera distance | 10 Ft Respitrace cable length |
2. Sample size used for the test set and the data provenance (e.g. country of origin of the data, retrospective or prospective)
Not provided in the text. The document describes the system and compares its technical specifications to a predicate device, but does not detail a specific study with a test set of data.
3. Number of experts used to establish the ground truth for the test set and the qualifications of those experts
Not provided in the text.
4. Adjudication method (e.g. 2+1, 3+1, none) for the test set
Not provided in the text.
5. If a multi reader multi case (MRMC) comparative effectiveness study was done, If so, what was the effect size of how much human readers improve with AI vs without AI assistance
Not provided in the text. The RPM Respiratory Gating System appears to be an automated system for tracking respiratory patterns and controlling a radiation beam, rather than a diagnostic tool requiring human reader interpretation or augmented by AI in a traditional MRMC study context. The document does not mention any AI components or human reader studies.
6. If a standalone (i.e. algorithm only without human-in-the-loop performance) was done
The device itself is described as a system that "derives beam-hold signals from the patient chest motion, which it tracks using a video camera connected to a PC workstation." and "the radiation beam is actively gated by the system, so that the beam is held (not irradiating) when the motion is outside the thresholds set in the planning session." This implies a standalone algorithm-driven function. However, the text does not provide details of a specific "standalone performance study" with metrics. The presented information focuses on technical specifications and functionality.
7. The type of ground truth used (expert consensus, pathology, outcomes data, etc.)
Not provided in the text. No study or ground truth establishment method is described. The comparison is based on technical parameters of the device itself and its predicate.
8. The sample size for the training set
Not provided in the text.
9. How the ground truth for the training set was established
Not provided in the text.
§ 892.5050 Medical charged-particle radiation therapy system.
(a)
Identification. A medical charged-particle radiation therapy system is a device that produces by acceleration high energy charged particles (e.g., electrons and protons) intended for use in radiation therapy. This generic type of device may include signal analysis and display equipment, patient and equipment supports, treatment planning computer programs, component parts, and accessories.(b)
Classification. Class II. When intended for use as a quality control system, the film dosimetry system (film scanning system) included as an accessory to the device described in paragraph (a) of this section, is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to the limitations in § 892.9.