06-09-2012, 03:32 PM
Portable Telemedicine Monitoring Equipment
[attachment=33542]
Design Introduction
For our design, we wanted to provide a specialized in-home medical monitoring system. The following
sections provide background information about health issues and telemedicine.
Background
Our project focuses on several issues, including:
■ Medical—In medicine today, the focus has shifted from disease treatment to prevention and
health care. People care more about their health, and while disease prevention and health care have
become an indispensable part of their lives, daily care for current physical conditions can
eliminate problems and pain that could result from untreated conditions.
■ Social—With increasing attention on health and technological progress both home and abroad,
home health care engineering (HHCE) is an emerging discipline. It advocates the concepts of
medical treatment at home, self health care, and remote diagnosis, and combines technology with
medical treatment. While addressing the trends of an aging society, soaring medical expenses, and
increasing health demands in the 21st century, HHCE enables medical resource sharing and
improves medical care in remote areas, making it well received by society.
Telemedicine
Telemedicine, which integrates network and medical technology, generally comprises remote
diagnosis, expert consultation, information service, online checkups, remote communication, etc.
Based on computers and network communication, it implements remote transfer, storage, query,
comparison, display, and sharing of medical data, video, and audio information.
Function Description
The design offers an effective, convenient medical monitoring solution for home, community, and
home-care doctors. Designed mainly for user terminals, the monitoring equipment allows individuals
to easily check and analyze their health conditions by themselves and obtain physical information (e.g.,
biomedical signals such as ECG, EEG, EMG, respiration, temperature, etc). The equipment displays
these signals in graphics or waveforms so that individuals know intuitively whether their health
indicators are normal. Additionally, the caretaker can make preliminary pathological diagnosis using
the equipment’s analysis function. The system stores the physical information for subsequent data
analysis and processing. With the development of telemedicine, the system can connect patients to
medical service (e.g., a hospital, private practitioner, or monitoring center) and deliver the physical
information in real time to a remote database or doctor through the network. This feature helps manage
medical information databases and provides remote monitoring and diagnosis, allowing individuals to
enjoy timely and effective diagnosis without leaving home. See Figure 2.
Biomedical Signal Regulation Card Design
The biomedical signals are collected modularly, including the medical sensor, signal filtering
amplifying modulation circuit, and A/D sampling circuit. The modulation circuit selects different filters
and the amplified circuit according to the spectrum and scope of different biomedical signals. Using
ECG as an example, the signal is amplified via the pre-amplification block, including a right leg driver
to suppress common mode interference, a shield wire driver to eliminate lead wire interference, and the
tenfold set gains.
We designed the pre-amplification block using the Analog Devices AD620 medical amplifier. The
AD620 device is based on a modification of the classic three operational amplifier approach and is
integrated using a co-phase differential amplifier in parallel. The AD620 device has a wide power
supply range (± 2.3 V to ± 18 V), small size, and low power (it uses only a 1.3 mA maximum supply
current), making it a good fit for low-voltage, low-power applications. Other advantages include a high
common-mode rejection ratio, sound temperature stability, amplified bandwidth, and low noise. The
amplified signal is further magnified using filtering and a 50-Hz trap filter. The post gain is set as 1 to
100. Because the maximum ECG signal is several mV and the A/D conversion input signal is over 1 V,
the total gain is set as 1 to 1,000. Filtering uses a voltage-controlled voltage source second-order high
(low) pass filter to eliminate signals interference such as myoelectricity beyond 0.05 to 100 Hz, as well
as other high-order industrial frequency harmonics. Additionally, we used an active twin-T band-stop
filtering circuit to curb the 50-Hz industrial frequency interference.
[attachment=33542]
Design Introduction
For our design, we wanted to provide a specialized in-home medical monitoring system. The following
sections provide background information about health issues and telemedicine.
Background
Our project focuses on several issues, including:
■ Medical—In medicine today, the focus has shifted from disease treatment to prevention and
health care. People care more about their health, and while disease prevention and health care have
become an indispensable part of their lives, daily care for current physical conditions can
eliminate problems and pain that could result from untreated conditions.
■ Social—With increasing attention on health and technological progress both home and abroad,
home health care engineering (HHCE) is an emerging discipline. It advocates the concepts of
medical treatment at home, self health care, and remote diagnosis, and combines technology with
medical treatment. While addressing the trends of an aging society, soaring medical expenses, and
increasing health demands in the 21st century, HHCE enables medical resource sharing and
improves medical care in remote areas, making it well received by society.
Telemedicine
Telemedicine, which integrates network and medical technology, generally comprises remote
diagnosis, expert consultation, information service, online checkups, remote communication, etc.
Based on computers and network communication, it implements remote transfer, storage, query,
comparison, display, and sharing of medical data, video, and audio information.
Function Description
The design offers an effective, convenient medical monitoring solution for home, community, and
home-care doctors. Designed mainly for user terminals, the monitoring equipment allows individuals
to easily check and analyze their health conditions by themselves and obtain physical information (e.g.,
biomedical signals such as ECG, EEG, EMG, respiration, temperature, etc). The equipment displays
these signals in graphics or waveforms so that individuals know intuitively whether their health
indicators are normal. Additionally, the caretaker can make preliminary pathological diagnosis using
the equipment’s analysis function. The system stores the physical information for subsequent data
analysis and processing. With the development of telemedicine, the system can connect patients to
medical service (e.g., a hospital, private practitioner, or monitoring center) and deliver the physical
information in real time to a remote database or doctor through the network. This feature helps manage
medical information databases and provides remote monitoring and diagnosis, allowing individuals to
enjoy timely and effective diagnosis without leaving home. See Figure 2.
Biomedical Signal Regulation Card Design
The biomedical signals are collected modularly, including the medical sensor, signal filtering
amplifying modulation circuit, and A/D sampling circuit. The modulation circuit selects different filters
and the amplified circuit according to the spectrum and scope of different biomedical signals. Using
ECG as an example, the signal is amplified via the pre-amplification block, including a right leg driver
to suppress common mode interference, a shield wire driver to eliminate lead wire interference, and the
tenfold set gains.
We designed the pre-amplification block using the Analog Devices AD620 medical amplifier. The
AD620 device is based on a modification of the classic three operational amplifier approach and is
integrated using a co-phase differential amplifier in parallel. The AD620 device has a wide power
supply range (± 2.3 V to ± 18 V), small size, and low power (it uses only a 1.3 mA maximum supply
current), making it a good fit for low-voltage, low-power applications. Other advantages include a high
common-mode rejection ratio, sound temperature stability, amplified bandwidth, and low noise. The
amplified signal is further magnified using filtering and a 50-Hz trap filter. The post gain is set as 1 to
100. Because the maximum ECG signal is several mV and the A/D conversion input signal is over 1 V,
the total gain is set as 1 to 1,000. Filtering uses a voltage-controlled voltage source second-order high
(low) pass filter to eliminate signals interference such as myoelectricity beyond 0.05 to 100 Hz, as well
as other high-order industrial frequency harmonics. Additionally, we used an active twin-T band-stop
filtering circuit to curb the 50-Hz industrial frequency interference.