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.

Device Description

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.

AI/ML Overview

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.

Summary

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JUN 8 1999

K98 3629

Date Summary was prepared;

October 13, 1998

Submitter's Name:

Varian Oncology Systems 3045 Hanover Street Palo Alto. CA 94304

Contact Person:

Linda S Nash Regulatory Compliance & Radiation Safety Manager Phone (650) 424-6990 (650) 424-4830 FAX E-Mail linda.nash@os.varian.com

Device Name:

RPM Respiratory Gating System

Classification Name:

Radiographic ECG/Respirator Synchronizer, 90IXO

Predicate Device:

NIMS Respitrace System, K864886

Product Description:

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.

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Before the operator can work with the system, the operator must create or select patient and session data records from a patient information database. The operator then records new data or displays recorded data for the current patient and session.

When the system is used for planning, the treatment is simulated. The operator sees live fluoroscopic images of the simulated treatment field, which are used to set the gating thresholds applied to the motion plots simultaneously generated by tracking the respiration motion. When used for treatment, 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.

Intended Use:

To obtain tracking of the subject respiratory pattern for radiation therapy treatment.

Technological Characteristics:

See the attached "Comparison of Characteristics and Specifications Table".

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Table 2 shows substantial functional equivalence of RPM Respiratory Gating System and Respitrace technologies as respiratory monitoring devices. Only the specifications that respirated woman of RPM Respiratory Gating System are compared in the table.

Characteristic/Specification	RPM RespiratoryGating System	Respitrace	Comments
Objects physicallyattached to patient	Light foam blockwith retro-reflectivemarker on itattached to upperabdomen area	Respiband inductivecoil ribbon wrappedaround the patientstomach or rib cage
Wire connectionsmade to patient	None	Wires connectingRespiband to thecomputer andcontrol box
Measured parameter	Vertical position ofthe marker attachedto abdomen in videocamera field of view	Respitrace outputvoltage is a measureof inductance ofRespiband coilwrapped around theabdomen or ribcage. Inductancevaries with thelength of the coil,which in turn varies,with circumferenceof the band wrappedaround the body.	RPM RespiratoryGating Systemresponds to themotion of the wholebody as well asrespiratory motion,while Respitraceresponds to motiononly due toabdomen or rib cagesize change.
Maximum signalrange	0 to 479 (rowposition in verticalfield of view ofvideo image) forNTSC videocamera.	-5V to +5V	RPM RespiratoryGating Systemvertical camera fieldof view varies as afunction of camera-marker blockdistance. For theRPM RespiratoryGating Systemoptics the verticalFOV as a functionof distance is:V-FOV = 0.12 *Distance.
			For example at 250-cm distance the V-FOV is 30 cm.
Measurementresolution	0.1 pixels standarddeviation	1 mV	The RPMRespiratory GatingSystem resolution isequivalent to 1 /4800 of V-FOV.This translates to$0.1 * 30 / 480 =$0.00625 cm, or0.0625 mm at 250cm distance.
Measurement drift	None	10 mV per second
Sampling rate	30 Hz	200 samples/sec forA/D converter. TheRespitrace outputsignal bandwidth is25 Hz.
Distance to patient	15 Ft Maximumpatient-cameradistance	10 Ft Respitracecable length

Table 2 – Comparison of characteristics and specifications of RPM Respiratory Gating System and Respitrace

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Food and Drug Administration 9200 Corporate Boulevard Rockville MD 20850

1999 JUN

Linda Nash Regulatory Affairs & Quality Assurance Manager Varian Oncology Systems 3045 Hanover Street M/S H055 Palo Alto, California 94304-1129

Re:

K983629 RPM Respiratory Gating System Dated: March 8, 1999 Received: March 10, 1999 Regulatory Class: II 21 CFR 892.5050/Procode: 90 LNH Regulatory Class: I 21 CFR 892.1970/Procode: 90 IXO

Dear Ms. Nash:

We have reviewed your Section 510(k) notification of intent to market the device referenced above and we have determined the device is substantially equivalent (for the indications for use stated in the enclosure) to legally marketed predicate devices marketed in interstate commerce prior to May 28, 1976, the enactment date of the Medical Device Amendments, or to devices that have been reclassified in accordance with the provisions of the Federal Food, Drug, and Cosmetic Act (Act). You may, therefore, market the device, subject to the general controls provisions of the Act. The general controls provisions of the Act include requirements for annual registration, listing of devices, good manufacturing practice, labeling, and prohibitions against misbranding and adulteration.

If your device is classified (see above) into either class II (Special Controls) or class III (Premarket Approval), it may be subject to such additional controls. Existing major regulations affecting your device can be found in the Code of Federal Regulations, Title 21, Parts 800 to 895. A substantially equivalent determination assumes compliance with the Current Good Manufacturing Practice requirements, as set forth in the Quality System Regulation (QS) for Medical Devices: General regulation (21 CFR Part 820) and that, through periodic QS inspections, the Food and Drug Administration (FDA) will verify such assumptions. Failure to comply with the GMP regulation may result in regulatory action. In addition, FDA may publish further announcements concerning your device in the Federal Register. Please note: this response to your premarket notification submission does not affect any obligation you might have under sections 531 through 542 of the Act for devices under the Electronic Product Radiation Control provisions, or other Federal laws or regulations.

This letter will allow you to begin marketing your device as described in your 510(k) premarket notification. The FDA. finding of substantial equivalence of your device to a legally marketed predicate device results in a classification for your device and thus, permits your device to proceed to the market.

If you desire specific advice for your device on our labeling regulation (21 CFR Part 801 and additionally 809.10 for in vitro diagnostic devices), please contact the Office of Compliance at (301) 594-4613. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at (301) 594-4639. Also, please note the regulation entitled, "Misbranding by reference to premarket notification"(21 CFR 807.97). Other general information on your responsibilities under the Act may be obtained from the Division of Small Manufacturers Assistance at its toll-free number (800) 638-2041 or (301) 443-6597, or at its internet address "http://www.fda.gov/cdrh/dsma/dsmamain.html".

Sincerely yours,

CAPT Daniel G. Schultz, M.D. Acting Director, Division of Reproductive, Abdominal, Ear, Nose and Throat, and Radiological Devices Office of Device Evaluation Center for Devices and Radiological Health

Enclosure

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Varian Oncology System

Indications For Use

510(k) Number (if known):

Device Name: RPM Respiratory Gating

Indications for Use:

(PLEASE DO NOT WRITE BELOW THIS LINE-CONTINUE ON ANOTHER PAGE IF NEEDED)

Concurrence of CDRH, Office of Device Evaluation (ODE)

Prescription Use	OR	Over-The-Counter Use
(per 21 CFR 801.109)

(Division Sign-Off)

Division of Reproductive, Abdominal, ENT,
and Radiological Devices

510(k) Number	K983629
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Regulation Number and Section

§ 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.