RPM RESPIRATORY GATING SYSTEM

K983629 · Varian Medical Systems, Inc. · LHN · Jun 8, 1999 · Radiology

Device Facts

• Record ID: K983629
• Device Name: RPM RESPIRATORY GATING SYSTEM
• Applicant: Varian Medical Systems, Inc.
• Product Code: LHN · Radiology
• Decision Date: Jun 8, 1999
• Decision: SESE
• Submission Type: Traditional
• Regulation: 21 CFR 892.5050
• Device Class: Class 2

Intended Use

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

Device Story

The RPM Respiratory Gating System tracks patient respiratory motion to control radiation therapy delivery. A monochrome CCD camera with an infrared ring illuminator captures video of a retro-reflective marker placed on the patient's upper abdomen. A PC workstation performs real-time video digitization and image analysis to track marker position. During simulation, the system correlates respiratory motion with fluoroscopic images to establish gating thresholds. During treatment, the system monitors the marker; when motion exceeds defined thresholds, the PC sends a signal via a relay/IO board to the Clinac system to hold the radiation beam. This ensures radiation is delivered only when the target volume is within acceptable motion limits. The system is operated by clinical staff in a radiation therapy environment.

Clinical Evidence

No clinical data provided. Substantial equivalence is based on bench testing and technical comparison of performance specifications (sampling rate, resolution, drift, and signal range) against the predicate device.

Technological Characteristics

System consists of a monochrome CCD camera with infrared illuminator, retro-reflective marker block, and a PC workstation. Connectivity via relay/IO board to Clinac radiation therapy system. Software runs as a Windows NT application. Sensing principle: video-based motion tracking of marker position. Sampling rate: 30 Hz. Measurement resolution: 0.1 pixels standard deviation.

Indications for Use

Indicated for use as an attachment to radiation therapy simulators and Varian Clinac treatment systems to characterize patient respiratory patterns and trigger beam-hold during radiation therapy to limit beam-on time to specific points in the respiratory cycle where the target volume is within acceptable motion limits.

Regulatory Classification

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.

Predicate Devices

• NIMS Respitrace System (K864886)

Submission Summary (Full Text)

{0}------------------------------------------------

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 [phone] [phone] FAX E-Mail [e-mail]

# Device Name:

RPM Respiratory Gating System

#### Classification Name:

Radiographic ECG/Respirator Synchronizer, 90IXO

#### Predicate Device:

NIMS Respitrace System, K864886

#### Product 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.

{1}------------------------------------------------

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".

{2}------------------------------------------------

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 Respiratory<br>Gating System | Respitrace | Comments |
|-------------------------------------------|--------------------------------------------------------------------------------------------------------|---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| Objects physically<br>attached to patient | Light foam block<br>with retro-reflective<br>marker on it<br>attached to upper<br>abdomen area | Respiband inductive<br>coil ribbon wrapped<br>around the patient<br>stomach or rib cage | |
| Wire connections<br>made to patient | None | Wires connecting<br>Respiband to the<br>computer and<br>control box | |
| Measured parameter | Vertical position of<br>the marker attached<br>to abdomen in video<br>camera field of view | Respitrace output<br>voltage is a measure<br>of inductance of<br>Respiband coil<br>wrapped around the<br>abdomen or rib<br>cage. Inductance<br>varies with the<br>length of the coil,<br>which in turn varies,<br>with circumference<br>of the band wrapped<br>around the body. | RPM Respiratory<br>Gating System<br>responds to the<br>motion of the whole<br>body as well as<br>respiratory motion,<br>while Respitrace<br>responds to motion<br>only due to<br>abdomen or rib cage<br>size change. |
| Maximum signal<br>range | 0 to 479 (row<br>position in vertical<br>field of view of<br>video image) for<br>NTSC video<br>camera. | -5V to +5V | RPM Respiratory<br>Gating System<br>vertical camera field<br>of view varies as a<br>function of camera-<br>marker block<br>distance. For the<br>RPM Respiratory<br>Gating System<br>optics the vertical<br>FOV as a function<br>of distance is:<br>V-FOV = 0.12 *<br>Distance. |
| | | | For example at 250-<br>cm distance the V-<br>FOV is 30 cm. |
| Measurement<br>resolution | 0.1 pixels standard<br>deviation | 1 mV | The RPM<br>Respiratory Gating<br>System resolution is<br>equivalent to 1 /<br>4800 of V-FOV.<br>This translates to<br>$0.1 * 30 / 480 =$<br>0.00625 cm, or<br>0.0625 mm at 250<br>cm distance. |
| Measurement drift | None | 10 mV per second | |
| Sampling rate | 30 Hz | 200 samples/sec for<br>A/D converter. The<br>Respitrace output<br>signal bandwidth is<br>25 Hz. | |
| Distance to patient | 15 Ft Maximum<br>patient-camera<br>distance | 10 Ft Respitrace<br>cable length | |

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

{3}------------------------------------------------

·

{4}------------------------------------------------

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 [phone]. Additionally, for questions on the promotion and advertising of your device, please contact the Office of Compliance at [phone]. 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 [phone] or [phone], 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

{5}------------------------------------------------

# Varian Oncology System

# Indications For Use

# 510(k) Number (if known):

Device Name: RPM Respiratory Gating

Indications for Use:

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.

# (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 |
|---------------|---------|
|---------------|---------|