Overview Of Rx-1 Device Operation; Connecting To The Cellular Network And Signal Strength - VivaQuant Rhythm Express RX-1 User Manual

Chapter 4: Using the RX‐1 to Monitor a Patient
Overview of RX‐1 Device Operation
The device acquires a two‐channel ECG, continuously evaluates the incoming signals to remove noise, and detects
bradycardia (brady), tachycardia (tachy), pause, and atrial fibrillation (AF) using an on‐board embedded algorithm. RX‐1
can also mark patient triggered events and offers the patient the ability to select from a menu of common symptoms to aid
in assessment of symptom‐rhythm correlation. RX‐1 uses standard DIN40 ECG lead wires to connect to standard
commercially available skin electrodes to sense the patient's ECG. A cellular modem embedded within the RX‐1 is used to
establish a secure communications link to a server that is accessible from a monitoring center or clinic. Auto‐ and patient‐
triggered ECG arrhythmia strips are communicated to the server for viewing and incorporation into a report by a medical
professional.

Connecting to the Cellular Network and Signal Strength

To maximize cybersecurity, all communications with the server are originated by the device. The device attempts to
communicate with the server upon the following conditions: (Note that for a connection to be established, cellular service
must be available. If no cell service is available, the device will retry until a connection is established.)

Expiration of the server connection interval timer. This timer, built into the device, causes the device to attempt a
connection at regular intervals (i.e. every 30 minutes). Whenever the device connects, all rhythm information is
transferred to the server.

Upon a patient triggered event. When the device is actively recording, and the patient presses the Red PTE button (for
5 seconds) on the device, the device marks the time of button press and initiates communication with the server via
the cellular modem.

When the device detects an arrhythmia meeting urgent criteria, it attempts to establish a communication link with the
server to avoid the potential delay of waiting for expiration of the server connection interval timer. Auto detection of
an arrhythmia that meets urgent criteria. Urgent criteria are determined by a physician and are selected for clinical
import. For example, a physician may have selected a routine tachycardia threshold to be 140 bpm but selected urgent
tachycardia threshold to be 180 bpm.

A connection can be manually initiated by pressing the red PTE button for more than 5 seconds if the device is in
Standby, Charging, or Recording. If the device just connected, or tried and failed to connect, the device will wait about
1 minute before attempting to connect.
When the device is connected or attempting to connect to the server, the cloud icon appears on the display. The cellular
signal icon is updated when the modem first connects to the tower and continues to display signal strength until
disconnected. When the device is not connected, the cell signal strength icon is not updated and the cloud icon disappears.
11