International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 5, Issue 2, February 2015)
Electromyography Monitoring Using Bluetooth Technology
Shweta A. Borkar1
1
ME, Department of Electronics & Tele Communication, Rajendra Mane College of Engineering & Technology, Ambav
Abstract— The design of portable systems for remote
monitoring of muscle activity is one of the most important
fields in telemedicine and telecare. We proposed the
peripheral nerve stimulator with electromyography which is
used for monitoring of muscle relaxation during the conduct
of anesthesia for surgical procedure which is a integral part of
patient safety. In this paper we present a low cost, portable
system with wireless transmission for real time EMG
acquisition, archiving and visualization in a mobile phone .
We have implemented the acquisition module and the
visualization tool for the mobile device.
II. NERVE CONDUCTION
Nervous system is basically divided into Peripheral
nervous system and Central Nervous system. The Central
Nervous system consist of brain and spinal cord while the
Peripheral nervous System consist of all the nerves outside
brain and spinal cord. The smallest functional unit to
describe the neural control of the muscular contraction
process is called a Motor Unit [8]. An ionic equilibrium
between the inner and outer spaces of a muscle cell forms a
resting potential at the muscle fiber membrane
(approximately -80 to -90 mV when not contracted). This
difference in potential which is maintained by
physiological processes (ion pump) results in a negative
intracellular charge compared to the external surface. The
activation of an alpha-motor anterior horn cell (induced by
the central nervous system or reflex) results in the
conduction of the excitation along the motor nerve. After
the release of transmitter substances at the motor endplates,
an endplate potential is formed at the muscle fiber
innervated by this motor unit. The diffusion characteristics
of the muscle fiber membrane are briefly modified and Na+
ions flow in. This causes a membrane Depolarization which
is immediately restored by backward exchange of ions
within the active ion pump mechanism, the repolarization.
The depolarization – repolarization cycle forms a
depolarization wave or electrical dipole which travels along
the surface of a muscle fiber on the surface and negatively
charged from inside the membrane. With the stimulus
generated by the axon or external stimulus these charges
are reversed thus creating a temporary reversal of potential
which in medical terminology is called an
impulse(stimulus).The axon of motor nerve coming from
spinal cord ends at or near the muscle. It transmits impulse
to muscle fiber . The junction between the terminal fibers
of motor axon and the muscle fiber is called neuromuscular
junction[9]. This process of transmitting impulse from
motor axon to muscle fiber occurs with the help of release
of a chemical substance called acetylcholine from nerve
ending, leading to contraction of muscle.
Keywords— Electromyography (EMG), Bluetooth, Nerve
Stimulation, Precision, Electrodes.
I. INTRODUCTION
The progresses achieved by electronics in medical field
during these last decades are undoubtedly completely
remarkable. Use of simple Peripheral Nerve Stimulator is a
common practice in Anesthesia where drugs are used to
paralyze patients under anesthesia so that they will not
move during a surgery and hence the operation result is
successful. The present practice today is assessment of
degree of neuromuscular block produced by these drugs is
by simple visual impression of finger movement due to
muscle contraction secondary to motor nerve stimulation
by Peripheral Nerve Stimulator
and hence merely
subjective in nature. Muscle relaxants are employed in
anesthesia to provide muscle relaxation and/or abolish
patient movement. Monitoring the magnitude of
neuromuscular block is accomplished by delivering an is
template. electrical stimulus externally near a peripheral
motor nerve and evaluating the evoked response of muscle
contraction innervated by that nerve.
In this paper, we proposed PNS with electromyography
to stimulate motor nerve which leads to contraction of a
muscle of hand or leg and thus the resultant magnitude of
muscle contraction (action potential) is sensed by EMG
sensor more precisely. This data is then transmitted via
Bluetooth to mobile device of the doctor.
85
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 5, Issue 2, February 2015)
As a result any signal that is ―common‖ to both detection
sites will be removed and signals that are different at the
two sites will have a ―differential‖ that will be amplified.
The low values typical of the EMG acquired by the sensors
(values between 1 and 3 mV) require the use of an
amplifier with a gain of 1000, a bandwidth between 0,05
and 200 Hz and a CMRR greater than 110 dB.
III. DESIGN
The architecture of stimulator is as described as follows.
Mobile Phone/PC
Bluetooth
Keyboard
dsPIC
D. Signal Conditioning
This module consists of a band pass filter to eliminate
the continuous component and high frequency noise.
Surface
electrodes to
patient’s body
E. ECG Signal Digitization
There are many microcontrollers used in ECG monitors,
from 8-bit to 32-bit microcontrollers, as well as DSPs. In
this design, we propose the use of dsPIC microcontrollers
(dsPIC30F3010/3011), which are able to acquire and
process the signals needed in monitoring applications.
Owing to the cost-effectiveness of the devices, it is
economically feasible to embed any number of them within
a machine or process. In the system design, the speed of
computation and memory capacity are considered as the
two most important characteristics. Since the
dsPIC30F6010 device has these properties, it has been
chosen for our design.
Sensor with
Preamplifier
Fig.1. Block diagram of EMG monitoring with Bluetooth
A. PNS Keyboard
It is used to set current and provide various stimulations
with various parameters such as pulse duration, pulse width
etc. which are required to stimulate the motor nerve.
Facility is provided for incrementing and decrementing the
current to be set..
F. Bluetooth Data Transmission
Several wireless technologies can be used to transmit
ECG signals, such as GSM/GPRS, Bluetooth, ZigBee,
WLAN IEEE 802.11, and so on .In this proposal we choose
Bluetooth technology and other possibilities can be tested
in future works. To provide Bluetooth we choose
BlueSmirf module. It is a class 1 model that has an
approximate range of 100 meters. The asynchronous data
from the dsPIC microcontroller are delivered to the
BlueSmirf Bluetooth module on the serial port. The
Bluetooth module is configured as a slave and the mobile
phone is considered to be functioning as a master.
The signal acquisition unit sends data to the Bluetooth
module, which transmits data continuously, in blocks of
EMG samples. Both the microcontroller and the Bluetooth
chip are involved in this process. Packets that contain
signal information are sent to the chip, using their USART
module as interface.
B. Surface Electrodes
These are silver chloride electrodes generally used in
EMG which are easily available in market. The impulse
delivered by the proposed PNS is applied to skin via these
electrodes.
C. Preamplifier
The design of preamplifier is most critical aspect of this
device. It is desirable to obtain an EMG signal that contains
maximum amount of information from EMG electrodes
and minimum amount of contamination from electrical
noise. For this purpose OP07 instrumentation amplifier
which acts as an differential amplifier is used. In order to
eliminate the potentially much greater noise signal from
power line sources, a differential detecting configuration is
employed. The signal is detected at two sites by two
electrodes, preamplifier circuit subtracts the two signals
and then amplifies the difference.
86
International Journal of Emerging Technology and Advanced Engineering
Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 5, Issue 2, February 2015)
IV. RESULT
The wireless EMG system presented in this work was
able to detect and transmit the basic elements of the EMG
waveform with high quality and efficiency. The current
system has the advantages of low cost and low power
consumption. In this, PIC microcontroller enables to make
easy, fast and flexible design and implementation. It
generates PWM depending on selection of stimulation
which stimulates motor nerve. The action potential
obtained from muscle contraction is sensed by EMG
sensor, amplified and sent to mobile using Bluetooth. The
magnitude of contraction is displayed in numerical format
thereby making the device highly objective in terms of
getting accurate results during anesthesia and surgery.
REFERENCES
[1]
[2]
[3]
[4]
[5]
[6]
Fig.2. Simulation result for Instrumentation amplifier
V. CONCLUSION
[7]
In this paper, we presented the design of a mobile
personal electromyography monitoring system. An EMG
signal acquisition circuit was integrated in a module that
communicates with a smart mobile phone via Bluetooth.
[8]
[9]
87
H.Kailanto, E. Hyvarinen ‖Mobile ECG measurement an a Analysis
System Using Mobile Phone as the Base Station.
S. Arslan, K Kose ‖A Design of DSPIC Based Signal Monitoring
and Processing System.‖ JOURNAL OF ELECTRICAL and
ELECTRONICS ENGINEERING, Istanbul, number 1, volume 9.
2009.
C.Rodriguez, S. Borromeo ‖Wireless ECG based on Bluetooth
protocol: design and implementation‖
Steffan Pavel, Michal Pavlik. ‖Smart differential pressure sensor
with Bluetooth communication interface‖. Third International
Conference on Systems, IEEE 2009.
T. K. Kho, Rosli Besar, Y. S. Tan, K. H. Tee, K. C.Ong, ―Bluetooth
enabled ECG Monitoring System‖,Tencon 2005 IEEE Region 10,
2005, pp.1-5.
I. Romero Legameta, P.S.Addisson, N. Grubb, CE Cobertson, KAA
Fox, J.N. Watson, "Real-Time Classification of ECGs on a PDA,"
IEEE Trans. On Information Technology in Biomedicine.,vol. 30,
pp. 565--568, 2003.
P.Bifulco, G. Gargiulo ‖Bluetooth Portable Device for Continuous
ECG and Patient Motion Monitoring During Daily Life .‖ Medicon
2007, IFMBE Proceedings 16, pp.369-372, 2007.
Anne Waugh and Allison Grant,Anatomy and Physiology in Health
and Illness
Angela Forster and Nigel Palastanga,2002.Clayton’s Electrotheraphy
Theory and Practice