Oxitone 1000M User manual

CAT.NO.OM2002 25.01.2021
Rev. 1.2
User Manual
Oxitone 1000M
Spot check wrist worn pulse oximeter

Oxitone 1000M
User Manual Rev. 1.
2
Page 2 of 39
Important
This user guide is subject to periodic review, update and revision. Customers are cautioned to
verify that the manual's information applies to the software and hardware present in the
equipment.
The product performs as described and in accompanying labels when assembled, operated,
maintained and repaired in accordance with the instructions provided.
This product must be cleaned and checked periodically. Do not use a defective product. Parts that
are broken, missing, plainly worn, distorted or contaminated should be replaced immediately. Do
not repair this product or any of its parts other than in accordance with written instructions
provided by Oxitone.
The user of this product shall have the sole responsibility of any malfunction that results from
improper use, faulty maintenance, improper repair, unauthorized service, damage or alteration by
anyone other than Oxitone.
Oxitone Medical Ltd. Is liable for the safety, reliability or the performance of this instrument only if:
 The instrument has been used according to the accompanying operating instructions.
 Any fittings, readjustments, changes or repairs have been carried out by Oxitone Medical
Ltd. authorized representatives or agents.
Information provided by Oxitone is believed to be accurate and reliable. However, Oxitone
assumes no responsibility for the use of such information nor for any infringement of patients or
other rights for third parties, that may result from its use.
This user guide is intended to provide the necessary information for proper operation of the
Oxitone 1000M Caution: Federal law (U.S.) restricts this device to sale by or on the order of
a licensed physician.
For further information contact:
Oxitone Medical Ltd.
17 Atir Yeda Street - Kfar Saba, Israel 4464312
Office: [phone] Fax: [phone]
Email: [e-mail]
E-mail: [e-mail]
Web Site: http://www.Oxitone-medical.com

Oxitone 1000M
User Manual Rev. 1.
2
Page 3 of 39
CE Notice
Marking by the CE symbol indicates compliance of this device with the European Medical Device
Directive 93/42/EEC concerning Medical Devices. This non-invasive pulse oximeter is designed
according to the international standard ISO13485:2016, medical devices.
EC
REP
EU authorized representative for Oxitone Medical Ltd.:
MedNet EC-REP GmbH
Borkstraße 10 | 48163 Münster | Germany
www.mednet-eurep.com
UDI: (01) 07290017350004
Rev. Date History Change
1.0 4 April 2020 Initial Document
1.1 16 Aug 2020 Correct and add that under normal conditions, the battery will lose
less than 25% capacity after lasts for approximately 300
charge/discharge cycles instead of 250 charge/discharge cycles.
Correct capacity to Approximately 24 hours after full charge.
Update Logo
1.2 25 Jan 2021 Update EC REP name, Update Logo, Correct UDI, update charger
label and monitor label.
Disclaimer
Information provided by Oxitone Medical Ltd. is believed to be accurate and reliable. However,
Oxitone Medical Ltd. assumes no responsibility for the use of such information, nor for any
infringements of patents or other rights of third parties, that may result from its use.
PLEASE READ THIS USER MANUAL BEFORE OPERATING THE SYSTEM.

Oxitone 1000M
User Manual Rev. 1.
2
Page 4 of 39
Table of Contents
1. About This User Manual 5
1.1. TYPES OF WARNINGS, CAUTIONS AND NOTES ................................................................................................ 5
2. Overview of System 6
2.1. DESCRIPTION OF DEVICE ........................................................................................................................................ 6
3. Conditions for Use 7
3.1. INDICATIONS FOR USE ............................................................................................................................................ 7
3.2. CONTRAINDICATIONS ............................................................................................................................................ 7
3.3. OXITONE 1000M BLE CONNECTIVITY………………………………………………………………………………………………………………. 7
4. Safety 8
4.1. ELECTRICAL SAFETY ............................................................................................................................................... 8
4.2. EMC COMPLIANCE .............................................................................................................................................. 8
4.3. SAFETY INSTRUCTIONS ........................................................................................................................................... 8
5. Setting Up the System 12
5.1. SYSTEM COMPONENTS ........................................................................................................................................ 12
5.2. PREPARING FOR USE............................................................................................................................................ 13
5.2.1. Initial setup ........................................................................................................................................... 13
5.3. PUTTING ON THE WRIST WORN DEVICE .................................................................................................................... 14
Correct placement .......................................................................................................................................... 14
Incorrect placement ....................................................................................................................................... 15
5.4. POWER ON AND DISPLAY STARTUP SCREEN ............................................................................................................. 15
6. Monitoring 16
6.1. MONITORING SCREEN AND DISPLAY SYMBOLS .......................................................................................................... 16
6.2. NUMERIC DISPLAY – SPO2 .................................................................................................................................. 18
6.3. NUMERIC DISPLAY – PULSE RATE .......................................................................................................................... 18
6.4. TIME SCREEN ..................................................................................................................................................... 18
6.5. STEPS SCREEN .................................................................................................................................................... 19
6.6. ALARM AND MESSAGES ........................................................................................................................................ 20
7. Labels and Symbols 21
7.1. DEVICE LABEL .................................................................................................................................................... 21
7.2. CHARGER LABEL ................................................................................................................................................. 21
7.3. SYMBOLS ......................................................................................................................................................... 22
8. Cleaning and Disinfecting 23
9. Service and Maintenance 24
9.1. CHARGING THE BATTERY ...................................................................................................................................... 24
9.2. ACTIVATE BLUETOOTH RADIO ............................................................................................................................... 24
9.3. SERVICE AND REPAIR POLICY ................................................................................................................................. 27
10. Troubleshooting 29
11. Specifications and compliance standards 30
11.1. ACCURACY TESTING .......................................................................................................................................... 32
11.1.1. Manufacturer's Declaration (EMC) .................................................................................................... 33
11.1.2. Warranty ............................................................................................................................................. 39
11.2. LIMITED WARRANTY ......................................................................................................................................... 39

Oxitone 1000M
User Manual Rev. 1.
2
Page 5 of 39
1. ABOUT THIS USER MANUAL
This User Manual provides the information necessary to operate and maintain the Oxitone 1000M
wrist worn pulse oximeter device.
PLEASE READ THIS USER MANUAL BEFORE OPERATING THE SYSTEM. If any part of this User Manual
is not clear, contact Customer Support for assistance.
1.1. TYPES OF WARNINGS, CAUTIONS AND NOTES
Three types of special message appear in this User Manual:
Warning: A warning indicates precautions to avoid the possibility of personal injury or
death.
Caution: A caution indicates a condition that may lead to damage to equipment, or a lower
quality of treatment.
Note: A note provides other important information.
PLEASE RETAIN THIS USER MANUAL FOR FUTURE REFERENCE.

Oxitone 1000M
User Manual Rev. 1.
2
Page 6 of 39
2. OVERVIEW OF SYSTEM
2.1. DESCRIPTION OF DEVICE
The Oxitone 1000M wrist worn pulse oximeter is a small, lightweight, portable device that non-
invasively monitors and displays numeric values of arterial blood functional oxygen saturation of
arterial Hemoglobin (%SPO2) and pulse rate (P.R.). It is intended for spot-checking on adult patients
(18 years and above) in the hospital, clinics, long-term care and home use. It is not provided sterile
nor can it be sterilized.
Auxilary measurement
The Oxitone 1000M direct mode skin temperature sensor is designed for use in routine continuous
monitoring of skin temperature when the other sensors which might better reflect core body
temperature are not available. The sensor is designed for placement on the surface of the wrist hand
skin.
Principles of operation
The Oxitone 1000M pulse oximeter uses a two-wavelength pulsatile system-red and infrared light-to
distinguish between oxygenated (O2Hb) and reduce (HHb) hemoglobin, each of which absorbs
different amounts of light emitted from the oximeter sensor. The system then calculates the relative
percentage of these two constituents and displays functional SpO2. The skin temperature sensor is
placed on the surface of the skin and is a part of the plastic enclosure that provides thermal
insulation (isolated from ambient temperature) for more accurate skin temperature measurement.
Important note:
Skin temperature:
Temperature of the skin of the PATIENT at a point on which the sensing device intended to measure
the temperature is placed [SOURCE: IEC60601-2-19:2009]. The Oxitone 1000M can measure skin
temperature as a relative indication of surface temperature. It is not intended to be used to
indicate core body temperature or to measure a fever.
Features and benefits
• Simple, intuitive operation
• Automatic self-test at start-up. After start-up, the monitor continuously performs background
self-tests.
• Compact, durable, lightweight, ergonomic hand wrist attached.
• Spot check tests results in up to 15 seconds.
• Recharge battery operation for approximately 24 hours.
• Easy-to-read OLED display in subdued lighting conditions.
• Battery status reporting.
• Vibration shaker (ERM) for On/Off, battery depletion and system error.
• The device requires no calibration or maintenance other than battery recharging.
Spot-on connectivity
• Easily integrates into most telemedical devices via BLE smart wireless technology (PC APP).

Oxitone 1000M
User Manual Rev. 1.
2
Page 7 of 39
3. CONDITIONS FOR USE
3.1. INDICATIONS FOR USE
The Oxitone Model 1000M Pulse Oximeter is a small, wrist-worn device indicated for use in
measuring and displaying functional oxygen saturation of arterial hemoglobin (% SpO2) and pulse
rate. It is intended for spot-checking of adult patients with wrist between 13-22 cm circumferences
in hospitals, clinics, long-term care, and home use.
3.2. CONTRAINDICATIONS
See Sec' 4.3 Safety Instructions
3.3. OXITONE 1000M BLE CONNECTIVITY
BLE Technology
BLE (Bluetooth Low Energy) technology allows wireless connections between electronic devices. The
technology is based on a radio link that offer fast and reliable data transmissions. BLE uses a license-
free, globally available frequency range in the ISM band-intended which ensures communication
compatibility worldwide.
Oxitone's use of BLE technology allows all the device's measurements to be transmitted compatible
BLE-enabled device. BLE connectivity gives patients increased ability to move freely.
Oxitone 1000M use of BLE wireless technology allows SpO2 and pulse rate data to be transmitted
through a Bluetooth radio to a compatible Bluetooth-enable device.

Oxitone 1000M
User Manual Rev. 1.
2
Page 8 of 39
4. SAFETY
4.1. ELECTRICAL SAFETY
The device complies with requirements of IEC/EN 60601-1 for general requirements for safety of
medical electrical equipment:
 Class II Equipment type BF applied part
 Mode of operation: Spot check
 Degree of mobility: Portable.
4.2. EMC COMPLIANCE
This device has been tested and found to comply with the IEC60601-1-2:2007 standard and with
CISPR 11:2009+A1(10) Group 1 Class B limits
4.3. SAFETY INSTRUCTIONS
Warnings
Do not use with patients with significant deformity, swelling, irritation, degenerative changes or
edema of the hand wrist.
Do not use with patients with localized infection, ulceration or skin lesions involving the wrist.
Do not use with patients that have restricted blood flow e.g. tourniquet, pressure cuff or IV line.
Do not use with patients with tremors or convulsions.
Do not use with patients with peripheral vascular disease affecting the hands.
Do not use with neonatal or pediatric patients.
This device is not defibrillation proof per IEC60601-1.
Do not use the device in an MR environment or in an explosive atmosphere.
In case of discomfort, inspect the device sensor application site to ensure correct sensor
alignment and skin integrity.
Avoid excessive pressure to the sensor application site as this may cause damage to the skin
beneath the sensor (device straps tighten).
The Oxitone 1000M is located on the patient wrist to activate the device properly. Check the
application site every 4 hours for skin integrity. If there is any concern, remove the Oxitone
1000M and replace with another pulse oximeter with a different application site.
Patient sensitivity varies depending on medical status or skin condition.
This device is intended only as an adjunct in patient assessment it must be used in conjunction
with other methods of assessing clinical signs and symptoms.

Oxitone 1000M
User Manual Rev. 1.
2
Page 9 of 39
The device must be able to measure the pulse properly to obtain an accurate SPO2
measurement. Verify that nothing is hindering the pulse measurement before relying on the
SPO2 measurement.
Operation of this device below the minimum amplitude of 0.3% modulation may cause
inaccurate results.
General operation of the device may be affected by the use of an electrosurgical unit (ESU). This
device should not be used adjacent to other equipment. If adjacent use is necessary, the device
should be observed carefully to verify normal operation.
Keep the oximeter away from young children.
Oxitone 1000M monitor is intended for indoor operation.
The monitor should not be used as a substitute for laboratory blood analyzer.
Do not use before reading and understanding this user guide.
Not for use in shower, bath tub, sink or pool.
Excessive device wearing pressure for prolonged periods can induce pressure injury.
Only apply the device on clean, intact wrist skin.
Do not use the Oxitone 1000M outside the declared environmental conditions (see Section
Error!
Reference source not found.). Operating the device outside the declared environmental
conditions can lead to incorrect measurements.
Do not use the device when alarms are required.
Cautions
The device is designed to determine the percentage of arterial oxygen saturation of functional
hemoglobin. Factors that may degrade pulse oximeter performance or affect the accuracy
of the measurement include the following:
* Improperly applied device * Anemia or low hemoglobin
* Jewelry or ornaments on the tested hand wrist concentrations
* Poor pulse quality * Carboxyhemoglobin (COHB)
* Excessive motion * Venus pulsation
* Methemoglobin (Met Hb) * Dysfunctional hemoglobin
* Cardio green or indocyanine and other intravascular dyes
* Avoid Excessive light such as sunlight or direct home lighting and pulsating strobe lights
The device has no audible alarms and is intended for spot-checking.
The device may not work when circulation is reduced. Warm or rub the hand wrist area to
increase perfusion.
The device is designed to be attached to either hand wrist.

Oxitone 1000M
User Manual Rev. 1.
2
Page 10 of 39
To avoid the risk of confusing or misinterpreting patient data when transmitting data via
Bluetooth, verify the device is paired with the correct display unit.
Clean the device before applying it to a new patient (See section 8. Cleaning and Disinfecting)
Do not sterilize, autoclave, or immerse this device in liquid. Do not pour or spray any liquids
into the device.
Do not use caustic or abrasive cleaning agents, or any cleaning products containing ammonium
chloride or isopropyl alcohol.
Do not use cleaning solutions other than those recommended here, as permanent damage
could result (See Section 8. Cleaning and Disinfecting).
The device should not be used as a replacement or substitute for ECG based arrhythmia.
Pulse rate measurement is based on the optical signal detection of a peripheral blood flow pulse
and therefore may not detect certain arrhythmias.
Do not expose the Oxitone 1000M to excessive moisture such as direct exposure to rain.
Excessive moisture can cause the monitor to perform inaccurately or fail.
This device is a precision electronic instrument and must be repaired by Oxitone qualified
technical professionals. Field repair of the device is not possible. Do not attempt to open the
case or repair the electronics. Opening the case may damage the device and void the warranty.
A functional tester on the market cannot be used to assess the accuracy of the pulse oximeter
monitor.
The equipment complies with IEC60601-1-2 Class B for electromagnetic compatibility for
medical electrical equipment and / or systems. This standard is designed to provide reasonable
protection against harmful interference in a typical medical installation. However, because of
the proliferation of radio frequency transmitting equipment and other sources of electrical
noise in health care and other environments, it is possible that hig
h levels of interference due to
close proximity or strength of a source might disrupt the performance of this device. Medical
electrical equipment needs special precautions regarding EMC, and all equipment must be
installed and put into service according to the EMC information specified in this manual – see
Section 11.1.1. Manufacturer's Declaration (EMC).
Radios and cellphones can affect the device and must be kept at least 10 meters (33 feet) away
from the device.
Portable and mobile RF communications equipment including CT, MRI, diathermy, RFID, and
electronic article security systems can affect medical electrical equipment.
Follow local, state, and national governing ordinances and recycling instructions regarding,
disposal or recycling of the device and device components, including batteries.
In compliance with the European Directive on Waste Electrical and Electronic equipment (WEEE)
2002/96/EC, do not dispose of this product as unsorted municipal waste. This device contains
WEEE materials; please contact your distributor regarding return or recycling of the device. If
you are unsure how to reach your distributor, please call Oxitone Medical Ltd. for your
distributor’s contact information.
Do not disassemble any part from the device.
Do not use if the device casing is damaged.
This monitor is not user-serviceable.

Oxitone 1000M
User Manual Rev. 1.
2
Page 11 of 39
Not for use in the presence of a flammable anesthetic.
Oxitone 1000M use of Bluetooth wireless technology allows SpO2 and pulse rate data to be
transmitted through a Bluetooth radio to a compatible Bluetooth device giving patience
increased ability to move freely – without being hindered by cables. Oxitone 1000M module
uses a Bluetooth radio with a range of about 10 meters (33 feet) (spherical radius). Moving
outside this range may cause missing or lost data.
Skin temperature values is not body core temperature (vital sign).

Oxitone 1000M
User Manual Rev. 1.
2
Page 12 of 39
5. SETTING UP THE SYSTEM
5.1. SYSTEM COMPONENTS
The components of the Oxitone 1000M system are shown below:
Wrist device – front view 5.1.1
Device enclosure
OLED screen
Attachment Velcro
(wristband)
Power On/Off

Oxitone 1000M
User Manual Rev. 1.
2
Page 13 of 39
Wrist device – rear view 5.1.2
Battery charger
5.2. PREPARING FOR USE
To operate the Oxitone 1000M effectively, the operator must:
 Be familiar with its controls and operation.
 Understand its status and messages (see Section 6.1. Monitoring Screen and Display Symbols
and Section Error! Reference source not found.).
Caution: The Oxitone 1000M is designed to operate on adult patients with wrist
between 13-22 cm circumferences.
5.2.1. INITIAL SETUP
 Inspect the Oxitone 1000M case for damage.
 Fully charge the device – see Section 9.1. Charging the Battery.
Note: The initial battery charge can take up to 2 hours. The battery should be
recharged as needed, before the Oxitone 1000M can be used.

Oxitone 1000M
User Manual Rev. 1.
2
Page 14 of 39
5.3. PUTTING ON THE WRIST WORN DEVICE
Note: Make sure the device is fully charged before wearing it. See Section 9.1.
Charging the Battery for charging instructions.
Place the device on your hand wrist with the optical aperture elastic concave surface (see below) on
top of the Ulna bone (the knobby protrusion of the wrist). The ON/OFF switch and the company logo
will face towards you.
Then secure the oximeter device by fastening the straps for stable and comfortable use. Avoid
excessive pressure to the monitor application site as a result of fastening the straps too tightly.
Optical aperture elastic concave surface left-hand Ulna bone
Note: If the device does not turn on, refer to “troubleshooting” for additional information.
CORRECT PLACEMENT
Correct placement of device, with the U-shaped part of device on top of the Ulna bone
Caution: Proper placement on your wrist is essential for SpO2 measurements.
Note: The device cannot be worn with the battery charger.

Oxitone 1000M
User Manual Rev. 1.
2
Page 15 of 39
INCORRECT PLACEMENT
Incorrect – device upside down
5.4. POWER ON AND DISPLAY STARTUP SCREEN
To start the system, press the Power On button on the front of the device for ½ a second:
The OLED screen will be illuminated and after releasing the button, the Oxitone logo will briefly
appear:
The Measurement in Progress screen will be displayed for a few seconds, during which the user
must stay still in order to get a first measurement:
Power On button

Oxitone 1000M
User Manual Rev. 1.
2
Page 16 of 39
6. MONITORING
6.1. MONITORING SCREEN AND DISPLAY SYMBOLS
Note: After 30 seconds, the screen display will automatically turn off. To switch display on,
press the button. Alternatively, you may turn your wrist in the natural motion of viewing a
watch, and the display will become visible.
After a brief pause, while the system is collecting information, the monitoring screen displays:
Monitoring screen – active monitoring Monitoring screen –oxygen monitoring inactive
1
Blue Tooth connection status
Blue Bluetooth symbol, indicates the device is connected to
another device.
Red Bluetooth symbol, indicates there is a problem with the BLE
component, if the indication persists after a power cycle, the
device needs servicing at Oxitone's service center.
White Bluetooth symbol, indicates the BLE is functioning but not
connected.
2
Battery charge level indicator
Low battery. Recharge battery
Critical battery depleted. After the device will issue a warning,
it will turn off after 30 seconds
Full charged battery
Note: When the system is
not monitoring a value, the
value is grayed-out.

Oxitone 1000M
User Manual Rev. 1.
2
Page 17 of 39
6.1.1 BLE Roles:
BLE roles are split into pre-connection and post-connection.
Pre-connection
At startup the Oxitone 1000M is either a peripheral or a central.
 A peripheral advertises itself and waits for a central to connect to it.
 A central scans for other devices, a central is usually a smartphone PC.
After a peripheral makes a connection it's called a slave, after a central makes a connection it's
called a master.
Post connection
After a BLE connection has been established, devices can be either a client or a server.
 A client accesses remote resources, a client is usually the master (host).
 A server has a local database of resources (profiles/services/characteristics), if provides
resources to the remote client. A server is usually a slave.
A client sends read and write operations to the server, and the server responds with data.
A server can send data to the client without a read/write request using indicate and notify
operations.
Oxitone 1000M has the role of a peripheral (server/slave).
3
Amount of oxygen in your blood (functional oxygen saturation of arterial
hemoglobin)
98 % System is monitoring OK
98 % System is not monitoring (value is grayed-out)
4 Your pulse rate. Pulse rate is the number of times your heart beats per minute.
65 System is monitoring OK
65 System is not monitoring (value is grayed-out)
5
Signal strength indicator
Relative signal strength

Oxitone 1000M
User Manual Rev. 1.
2
Page 18 of 39
6.1.2 Spot Checking
The oximeter device will start to measure and display values of % SpO2 and pulse rate (bpm) at
refreshing intervals of one second (SpO2 averaging time is 12 seconds). In order to insure optimum
accuracy, please note the following:
 Do not secure the device with tape.
 Ensure that the tested hand has unrestricted blood flow.
 Do not select a testing site near potential electrical interference.
FREQUENCY OF INSPECTION OF APPLICATION SITE FOR SKIN INTEGRITY
Inspect the application site, for intact skin, every four hours. If there is any change in the skin
integrity, remove the Oxitone 1000M to alternate wrist site.
6.2. NUMERIC DISPLAY – SPO2
A SpO2 reading is associated with correct device placement, measuring small physiological changes
during the measurement, and acceptable levels of arterial perfusion at the measurement site.
Inaccurate measurements may be caused by:
• Elevated levels of carboxyhemoglobin (COHb)
• Elevated levels of methemoglobin (Met Hb)
• Intravascular dyes such as indocyanine green or methylene blue
• Elevated levels of Bilirubin
• Severe anemia
• Low arterial perfusion
• Motion artifact
6.3. NUMERIC DISPLAY – PULSE RATE
The pulse rate displayed on the Oxitone 1000M may differ slightly from the heart rate displayed on
ECG monitors due to differences in averaging times.
Power off NA Strong click, aprox. 200msec
6.4. TIME SCREEN
A brief tap on the button will display the Time screen:

Oxitone 1000M
User Manual Rev. 1.
2
Page 19 of 39
If you tap the button again, the Steps screen will display (see below). Otherwise, after 30 seconds the
Measurement screen will automatically be displayed.
6.5. STEPS SCREEN
While viewing the Time screen, tap briefly on the button to display the Steps screen:
Note: Steps are calculated for the current day, from 12 am to 12 pm. At 12 am the
Steps value is automatically reset to zero.
After 30 seconds, the Measurement screen will automatically be displayed.
Note: steps monitoring defines as general wellness product. Intended for only general wellness use.
6.5.1 Skin Temperature
SKIN TEMPERATURE SCREEN
While viewing the Steps screen, tap briefly on the button to display the Skin Temperature screen:
The skin temperature value is updated every one second.
In case of temperature sensor malfunction, dashes will be displayed.
After 30 seconds, the Measurement screen will automatically be displayed.

Oxitone 1000M
User Manual Rev. 1.
2
Page 20 of 39
6.6. ALARM AND MESSAGES
Event Message type and duration Vibration type and duration
Power on Oxitone logo and version number is
displayed for aprox. 5 seconds
Strong vibration for 1 second
Signal acquisition on
power up
"Stay still measurement in progress"
message displayed until first
measurement is obtained
NA
Battery depleted "Low battery level" Pop up message
for 15 seconds (or button press).
Strong buzz for aprox. 350msec
Battery Critical "Please recharge battery" Pop up
message, until auto power off after 30
seconds.
Strong buzz for aprox. 350msec
BLE connection request "Press button to connect to…" Pop up
message for 15 seconds (or button
press if user confirms).
Strong buzz for 750msec
No power to charger "Please connect charger to wall
outlet" Pop up message until power
applied
Strong buzz for aprox. 350msec
Charger fault "Charger fault detected" Pop up
message until charger disconnects
Strong buzz for aprox. 350msec
System Error "#xxx Service required" Pop up
message, requires reset to remove.
1 Second