Technogym 0WR00914AA User manual

H
He ea ar rt t R Ra at te e
N
No oi is se e D De et te ec ct to or r
R EV . 1.1

HR Noise Detector: quick reference – rev. 1.1
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Contents
1. INTRODUCTION....................................................................................................................................................1.1
2. TECHNICAL NOTES ON CARDIO RECEIVERS.............................................................................................2.1
2.1. GENERAL INFORMATION............................................................................................................................2.1
2.2. ELECTROMAGNETIC INTERFERENCE FIELDS........................................................................................2.2
2.3. MECHANICAL VIBRATIONS........................................................................................................................2.2
2.4. POSITION OF THE RECEIVER......................................................................................................................2.3
3. HOW TO USE THE NOISE DETECTOR............................................................................................................3.4
3.1. DEVICE MAIN PARTS....................................................................................................................................3.4
3.2. FIRST START-UP ............................................................................................................................................3.4
3.3. FINDING ELECTROMAGNETIC NOISE.......................................................................................................3.4
3.4. NOISE DETECTOR SATURATION................................................................................................................3.5
3.5. ADDITIONAL NOTES.....................................................................................................................................3.5
3.6. POSSIBLE SOLUTIONS IN THE PRESENCE OF ELECTROMAGNETIC FIELDS ..................................3.6
3.7. HR NOISE DETECTOR BATTERY REPLACEMENT...................................................................................3.6
3.8. EXAMPLE OF USAGE: CASE HISTORY.......................................................................................................3.7

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HR Noise Detector: quick reference – rev. 1.1
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1. INTRODUCTION
Electromagnetic interference are increasing due to the increase of electronic equipments in
general, and the widest presence of our equipment on many facilities (hospitals, private
customers…). This could affect, most of the time, correct heart rate reception on our machines and
it could become really difficult to find out the real cause/source of the problem.
That’s why we developed the next device, that’s very useful to find out electromagnetic noises and
to understand the areas affected by it. We could finally prove the problem at customer, we could
move machines on a “free of noise” area, or we could find the source of the noise, so that customer
could find a way to switch it off or shield it, when possible.
We could also use this device as a preventive instrument, to check in a site, before the
installations, if any electromagnetic noises are present.
This manual contains notices and symbols which have a specific meanings:
Information about the operation in progress.
Observation about the operation in progress.

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2. TECHNICAL NOTES ON CARDIO RECEIVERS
2.1. GENERAL INFORMATION
Technogym utilizes Polar or Salutron technology for measuring the heart rate frequency of the
person training on the machine. The system consists of:
•a transmitter (Chest Belt), worn by the person training on the machine, which uses 2
electrodes to detect the electrical activity of the heart, and transmits the measured heart rate, by
sending an electromagnetic signal at a frequency of 5 KHz.
•A receiver, like the one in the figure below, installed in the machine, which consists of:
−an antenna a(coil), which receives the signal from the transmitter strap worn by the user.
−An integrated circuit b, which has the function of filtering the analog signal and generating a
pulse train corresponding to the received heart rate.
The receiver is connected to the CPU board by means of 3 wires used for:
−+5 Vdc power supply;
−Output signal (heart rate);
−Ground.
The output is a digital signal that is normally at 5 Vdc and goes to 0 Vdc, for a few msec., when
a heart beat is detected, as shown in the figure below.
Find more detailed information about that on all Excite Service manuals.

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2.2. ELECTROMAGNETIC INTERFERENCE FIELDS
There are 2 types of problems which can typically occur on the heart rate signals:
1) Electromagnetic interference: caused by disturbances from sources of electromagnetic noise.
This problems could cause:
•higher heart rate signal: HR deviate from the real value, typically making it higher.
•Saturation: in this case the disturbances from sources of electromagnetic noise is so high
that receiver is no longer able to detect any heart rate signal.
Interference may occur near high voltage power lines, overhead lines of electrical railway, electric
bus lines or trams, television, stereo speakers, neon lights, motors, computers, cell phones, air
conditioning systems, electro-medical devices.
Several pieces of equipment with electronic or electrical components, such as LED displays,
motors, and electric brakes, may cause interference with stray signal.
2) Cross-talk: similar to the interference problem, but this is caused by reception of a signal from
another Chest Belt, typically worn by users on adjacent machines, if they are too close together
(less than 1mt radius, on average). This cause HR beats incorrect reading, with usually higher
values, because the 2 signal received from the Chest Belts, can be summed together by the HR
receiver.
2.3. MECHANICAL VIBRATIONS
Mechanical vibrations may cause slight shifting of the coil, giving rise to transient impulses. If these
transients occur only occasionally they can be easily filtered by SW. However, if the mechanical
vibrations are periodic, they can produce periodic pulses which may be interpreted as correct heart
rate values.
To eliminate or reduce the effects of vibration the receiver is usually housed into a sponge (see pic.
below).

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2.4. POSITION OF THE RECEIVER
Carefully position the receiver according to the specifications below:
•the coil must be directed toward the user;
•the coil must be positioned well away (even a few centimeters) from the LEDs;
•the cable must be folded immediately after the connection on the receiver, so that it does not
pass near the coil;
•the cable, from the receiver to the CPU board connector, should be properly routed in order to
not pass over LEDs or electronic components that may cause interference.
•the receiver must be directed in such a way that its axis of reception is parallel to that of the
transmitter, as shown in the figure below:

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3. HOW TO USE THE NOISE DETECTOR
3.1. DEVICE MAIN PARTS
If you tap your finger on the Noise Detector casing, when device is ON, Red LED will
blink at each hit. This is because the noise generated by the vibration on the chassis, and can be
used to check if unit is ON and battery works.
Battery not included: refer to par.3.7 to install the battery the first time on the device.
3.2. FIRST START-UP
First always check if Noise Detector is properly working attending the next steps:
1. Switch it ON and check if LED is blinking when tapping on the casing, as explained before.
2. Wear a wet Chest Belt transmitter and check if LED regularly flash on.
Each LED blinking correspond to each heart rate beat detected.
3.3. FINDING ELECTROMAGNETIC NOISE
The HR Noise Detector is really sensitive to all electromagnetic fields produced by the switching
of LEDs, motor brushes, the commutation of power devices, monitors, neon lights, stereo
equipment, etc…
Indentification label
Coil side/ position
Red LED
Switch on/off butto
n

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This Noise Detector causes the LED to light for every heart beat and/or transient 5Khz frequency
detected: in this way it is possible to determine whether there is electromagnetic noise, and identify
its source.
Keep the Noise Detector in your hand, with the coil to the front, and check around the TG
machine and, in general, into the room to find possible electromagnetic noises.
When you can see red LED repeatedly flashes, that means an electromagnetic noise has been
found. Faster is the LED blinking frequency nearest is the electromagnetic noise source.
The presence of electromagnetic noises is easily recognizable, respect standard Chest Belt
HR beats, because generally accompanied by fast and irregular blinking of the LED. While
Chest Belt beats are always regular in time (same blinking speed/same duty cycle).
3.4. NOISE DETECTOR SATURATION
If an area is affected by high level of electromagnetic noise the Noise Detector may become
completely saturated. This phenomenon, depending on its intensity, may cause the device
impossible to receive any signal (LED always OFF), even if you wear a Chest Belt in front of it.
In this case it’s really important to have a well working and tested Chest Belt to test the
Noise Detector, to avoid any doubts: if no signal is received by the Chest Belt as well, the Noise
Detector is saturated. To prove it you can move into another room/ area to check when HR beats
are detected again.
3.5. ADDITIONAL NOTES
•HR Noise Detector is very sensible. You can find at all the 5Khz spurious transient or
periodic noise pulses. If you keep it nearby an ARM display, for example, LED will flash
fast because display’s LEDs and uP create electromagnetic noise. That’s why HR receiver, on
our cardio machine, is always housed in a fixed and pre-tested position, far enough from
ARM display or the other source of noise produced by our machines (mains power cables,
AT/ALE driver, WTV/ Visio electronic boards…)
•You can use the Noise Detector to check if distance from machine to machine is enough to
avoid cross talk phenomenon: when a user, wearing the Chest Belt, is training on one
machine, you can check at which distance the Noise Detector can still display beats. This to
prove at customer to respect the minimum machines required distance to avoid cross talking
issues.
Noise Detector, because its sensibility, can show beats even if you are far than 1mt
from the user wearing the Chest Belt. Cardio receivers installed on machines instead have

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got an additional software filter that make them less sensible. So if machines minimum
distance is respected, no cross talking issues will be present. From the other side we need
such sensibility on Noise Detector, to face out all the possible issues (worst condition).
Find more detailed information, about machines required minimum distance, on all
Excite Service manuals.
•Usually HR on TG machines can work even if machines are a little bit too near between
them, or even if a low level of electromagnetic noise is present around. Despite the Noise
Detector sometimes flashes a little bit. This is because the additional software filter on
cardio machines, just previously mentioned, and because when HR receiver succeed to link
to the nearest Chest Belt transmitter, it properly works ignoring the noises around, when far
and low.
•Vario Excite, by having the HR receiver far from the user, because the kind of frame and
training, is more susceptible to electromagnetic noise and cross talking. In fact greater is the
distance between HR receiver and Chest Belt, more difficult is for the receiver to
succeed to link to the Chest Belt (because it can be engaged before by other HR signal or
noises). That’s why in presence of low noises, when other machines could still succeed to
work, Vario could not. In this case it’s enough to increase the distance of Vario from the
noise source or from the other machines.
3.6. POSSIBLE SOLUTIONS IN THE PRESENCE OF
ELECTROMAGNETIC FIELDS
The only effective solution in the presence of electromagnetic interference is to reduce the power
of the noise source, in 2 possible ways:
•Shielding the noise source.
•Increasing the distance between the noise source and the HR receiver, by changing the
position of the machines or moving the noise source far from them, if possible.
3.7. HR NOISE DETECTOR BATTERY REPLACEMENT
Open the back casing and replace the battery by a standard 9Volt ones.

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3.8. EXAMPLE OF USAGE: CASE HISTORY
At a private house:
•Problem: Synchro Excite has got wrong heart rate beats during the training, usually
after 10, 15 minutes of training. Wrong because higher than normal (suddenly HR freq.
peaks). In the same room (basement room), there is also Recline and Run Excite that
doesn’t give any problem at all.
•Analysis: machine tested and HR works fine so it must be a noise that comes up after a
while. Check performed by Noise Detector all around: a source of noise nearby the
ceiling has been found. It’s the floor heating plant of the upper room. Other machines
are not affected because HR receiver and user are in a lower position than Synchro, and
noise come from the high.
•Solution: ceiling has been properly shielded by a professional company committed by
the customer.
At a hospital:
•Problem: Vario Excite doesn’t pick heart rate beats at all. All other Excite machines in
the room are working fine (Run, Bike, Recline and Step).
•Analysis: check performed by Noise Detector nearby the Vario. No beats are showed at
all, even by using a tested Chest Belt transmitter. Moving around in the room, nearby
the other machines, Chest Belt beats are correctly showed. Analyzing all the area by
using the Noise Detector we found that Vario was in a position, full of electromagnetic
noise that made Noise Detector become saturated as well. Moreover Vario is much
susceptible to noise than other machines (ref. par.3.5 “Additional Note”).
•Solution: Vario has been moved in a free “electromagnetic noise area”.
In a club:
•Problem: Bike Excite has got issues with HR frequency. Frequency is not always
correct: sometimes disappears, sometimes is too high (220 beats), sometime doesn’t
change (keeps low).
•Analysis: check performed by Noise Detector. Bike is the last machine of a row, and
it’s placed at the room corner. Electromagnetic interference has been found nearby that
corner. It came from a cabinet fixed to the floor containing some voltages regulators.
•Solution: Bike has been moved far enough from this noise.

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HR Noise Detector: quick reference – rev. 1.0
TECHNOGYM S.p.A.
Via G. Perticari, 20
47035 Gambettola (FC)
ITALIA
Tel.: [phone]
Fax: [phone]
e-mail: [e-mail]