The document provides instructions for storing, cleaning, maintaining, and disposing of a wearable product. Key details include:
- The product should be stored away from direct sunlight, extreme temperatures, dust, dampness, fires, electromagnetic fields, and vibrations.
- Clean the product surface with a dry lint-free cloth and do not use water. Clean electrodes with alcohol or disinfectants.
- Replace the battery if out of power or immersed in water for long periods. Replace damaged or expired electrodes. Seek help for mechanical damage.
- Dispose of the product according to local regulations after expiration, or recycle by returning to retailer or manufacturer.
1. Product manual part
Storage
The product should be stored in locations where is:
• No direct exposure to sunlight,
• No subject to extreme heat or high humidity,
• No exposure to dusts or dampness,
• Far away from fires or open flames,
• No exposure to strong electromagnetic fields,
• No exposure to strong mechanical vibration.
Cleaning and sterilization (for wearable units)
1. Clean the product surface using dry lint- free cloth each time before using.
2. Do not clean the product using poured water to avoid liquid from entering
the device. However, to prevent damage from salt or other electrolyte in
the sweat, cloth damped with clean water can be used for cleaning.
3. Clean the electrodes frequently using ethyl alcohol or other disinfectants.
4. Clean the product using alcohol-based sanitizer with special concern if the
product is going to be applied to other users to avoid cross-infection.
5. The product is not for surgical application thus needs no special
sterilization.
Maintenance (for wearable units)
1. Replace the battery when the battery is:
• Out of power,
• Immersed in water for a certain long time.
It is strongly recommended that the battery be checked regularly for
integrity and safety to avoid leakage or other potential hazards.
2. Replace the electrodes if any there is any damage or after the expiration.
3. If cracks, splits or other mechanical damages are observed, look for help
from the retailer or service center.
4. Check the product for accuracy especially after it undergoes any
mechanical damage. Checking service is available from the service center.
Recycle and disposal
The product shall be disposed into specific waste disposal subject to local
regulation after expire date. (Do not discard in the normal trash!)
Recycling by returning back the product to the retailer or mailing to the
company is optional.
2. Literature review (following 3.2)
(There seems to be no section for 3.3 in our previous report… I am wondering
put this part into the section 3.3 (between 3.2 and 3.4) with the subtitle of
‘Justification and determination for 3-lead ECG in chest aid monitoring’ and
the market review part right after what Max has written last time.)
Executive Summary
ECG (electrocardiogram) is the current “gold standard” for cardiac event
measurement and pathological diagnosis. Computer programs for
interpretation of ECG signals have been optimized to yield accuracy and
diagnostic value comparable to that of cardiologists 1
. In clinical evaluation
setting, 12-lead ECG has been a routine method for clinicians to make the
decision whether a patient shall be sent to the emergency room (ER) or not.
The accuracy in pre-hospitalization diagnosis by ECG would help in saving
time for determining the optimal treatment as well as directing more
sophisticated diagnosis. Here we justify the necessity and reliability of using
ECGs with reduced lead number (three) for pre-hospital diagnosis rather than
anatomically applicable and skill-required 12-lead ECGs.
Introduction
The critical need for 12-lead ECG arises from its diagnostic value in ST
elevation myocardial infarction (STEMI) 2
, one major type of coronary artery
disease (CAD, also termed ischemic heart disease). STEMI is now the no.1
killer in the U.S. as well as globally 3
and makes up for 25%~40% of the
patients diagnosed with acute myocardium infarction (AMI) in U.S, slightly
lower than NSTEMI annually 4
. Even with lower prevalence than angina
pectoris, another subtype of CAD, AMI has a much higher morbidity,
especially in males diagnosed with CAD 5
. Even though, STEMI has caused
millions of death and is expected to continue to cause more patients to die in
the coming future.
Discussion
The reason why some clinicians emphasize the importance of a 12-lead ECG
for diagnosis is that if there is any possibility of STEMI in patients, it could
lead to more accurate evaluation and prepare both the patients and the
physicians for necessary acute treatment since not all the hospitals would be
equipped with techniques to treat such disease 6,7
. Tough a 3-lead ECG can
also detect abnormality ST segment elevation, decreased detection rate and
duration of ST episode limits its diagnostic value in ischemia 11
.
It is worth considering that even with a 12-lead ECG, additional tests such as
X-ray are still required for diagnostic decision and improvement after the
primary treatment 8
. And even for STEMI, a 12-lead ECG can still lead to
3. measurement with false. For other cardiac conditions, a 12-lead ECG
provided less consistency with the clinical findings in detecting abnormalities
than a 3-lead ECG, suggesting a higher false positive or negative for 12-lead
ECGs 8
.
Moreover, when we target elder individuals, such as those who are over 55 or
60, a 12-lead ECG is expected to have decreased benefit. A 12-lead ECG
requires more time is more difficult to determine and thus is hard for patients
to self-administer 9
. Thus a 12-lead device appears to be less desirable (then
a 3-lead design) for daily monitoring especially for elder people or people with
certain disabilities.
From the prevalence use of 3-lead ECGs in portable medical devices and
during patient transport to the ER, no technical problems having been
reported in most medical diagnosis or tests and no clinical difference has
been observed between a 12-lead ECG and a 3-lead one. There are previous
clinical researches studying the correlation between 3-lead and 12-lead ECG
in diagnosis, which sometimes draw contrary conclusions10 11 12 13
. However,
after proper transformation and recovery of raw signals collected by the 3-lead
ECG, a 12-lead ECG-similar output can be achieved in many studies 14
.
Diseases that can be diagnosed by 3-lead ECG include right atrial
enlargement, advanced interatrial block, advanced superoanterior hemi- and
bifascicular block, inferior myocardial infarction, valve prolapse and some
other common cardiac diseases 15
. According to the significant overlap of
efficacy between 12-lead and 3-lead ECG in disease detection and diagnosis,
using 3-lead ECG in our product, for simplicity, seems a reasonable choice.
For commercialized cardiac monitors, the implanted ECGs with reduced leads
are of much more convenience for customers in applying, adjusting and
detaching the product. Many current cardiac monitoring (or diagnostic)
products use single-lead ECG. In such case, the products are limited to
detecting merely one disease 16
. Some other conditions including atrial
fibrillate (which can be detected even by a 2-lead ECG), AV conduction block
and etc. could be missed with these products.
Summary
A 3-lead ECG has multiple superiorities over the single-lead ECG and shows
considerable competitiveness in monitoring cardiac events as a 12-lead ECG
does (Table 1.). Accordingly, our product uses 3-lead ECG for detecting and
diagnosing for cardiac disorders.
4. ECG
type
Pros Cons
3-lead
ECG
• Convenience to USE
• Considerable diagnostic
information for most cardiac
diseases
• Higher cost-efficiency *
• Poor performance in
specifying MI subtypes
• Less information
12-
lead
ECG
• Detailed information for pre-
hospital diagnosis
• Better performance in specifying
MI subtypes
• Complexity for placing
• More difficult in
designing and
manufacturing
Table 1. Pros and cons of 3-lead and 12-lead ECG.
References
1. Willems, Jos L., et al. "The diagnostic performance of computer programs
for the interpretation of electrocardiograms." New England Journal of
Medicine325.25 (1991): 1767-1773.
2. James J. Augustine. The critical need for 12-lead EKG programs in EMS.
http://www.ems1.com/cardiac-care/articles/1343325
3. Martin, Joyce A., et al. "National vital statistics reports." National Vital
Statistics Reports 61.1 (2012).
4. White, Harvey D., and Derek P. Chew. "Acute myocardial infarction." The
Lancet 372.9638 (2008): 570-584.
5. US Department of Health and Human Services, and National Heart Lung
and Blood Institute. "Morbidity and Mortality (2012) Chartbook on
Cardiovascular."Lung and Blood Diseases (2012).
6. Tom Bouthillet. (2012, Apr 24). Who should receive a prehospital 12-lead
ECG? http://www.ems1.com/cardiac-care/articles/1276633
7. Su, Li, and Stefan Borov. "12-lead Holter
electrocardiography."Herzschrittmachertherapie+ Elektrophysiologie 24.2
(2013): 92-96.
8. Macfarlane, P. W., A. R. Lorimer, and T. D. Lawrie. "3 and 12 lead
electrocardiogram interpretation by computer. A comparison on 1093
patients." British heart journal 33.2 (1971): 266.
9. Antonicelli, Roberto, et al. "Validation of the 3-lead tele-ECG versus the 12-
lead tele-ECG and the conventional 12-lead ECG method in older
people."Journal of telemedicine and telecare 18.2 (2012): 104-108.
10. Tomasic, I., and Roman Trobec. "Electrocardiographic Systems With
Reduced Numbers of Leads—Synthesis of the 12-Lead ECG." Biomedical
Engineering, IEEE Reviews in 7 (2014): 126-142.
11. Klootwijk, P., et al. "Comparison of usefulness of computer assisted
continuous 48-h 3-lead with 12-lead ECG ischaemia monitoring for detection
and quantitation of ischaemia in patients with unstable angina." European
heart journal 18.6 (1997): 931-940.
12. Jernberg, Tomas, Bertil Lindahl, et al.. "ST-segment monitoring with
continuous 12-lead ECG improves early risk stratification in patients with
5. chest pain and ECG nondiagnostic of acute myocardial infarction." Journal of
the American College of Cardiology 34.5 (1999): 1413-1419.
13. Murray, R. G., et al. "Comparison of 12-lead and computer-analysed 3
orthogonal lead electocardiogram in coronary artery disease." British heart
journal 38.8 (1976): 773-778.
14. Tsouri, Gill R., and Michael H. Ostertag. "Patient-Specific 12-Lead ECG
Reconstruction From Sparse Electrodes Using Independent Component
Analysis." Biomedical and Health Informatics, IEEE Journal of 18.2 (2014):
476-482.
15. Wojciech, Zareba, et al. Noninvasive Electrocardiology in Clinical Practice.
New York: Futura Publishing Company, Inc. 2001. Print
16. Galloway, Connor D., David E. Albert, and Saul B. Freedman. "iPhone
ECG application for community screening to detect silent atrial fibrillation: a
novel technology to prevent stroke." Int. J. Cardiol. 165 (2013): 193-194.
6. Market summary
Current products Overview
Following the previous work on market for medical/fitness devices last
semester, we have been keeping an eye on the highly expanded market and
some typical and prevalent products that perform similar functions as our
device. Among the almost countless products that have been commercialized
during recently years, we pick some and tabulate them (Table 1.) for better
comparison and determination on market niche, and helping improve our own
design.
Category Product Compan
y
Highlights Deficiency Price ($)
Wearable
ECG
monitors
V-patch Intelesen
s
Medical-grade
Options for
1/3/12-lead ECG
Customer
-
depende
nt based
on
consultin
g
ZephyrLI
F™
(Home/H
ospital)
ZephyrLI
F™
Home-based or
hospital-based
options;
Chronic disease
and risk
management
supported by its
own portal
Only ECG
signals
collected
Customer
-
depende
nt based
on
consultin
g
VitalJack
et®
Biodevice
s
Options 1/5-lead
ECG
635.44
Intelligent
shirt
Ambiotex Multiple tech-
units;
Biofeedback;
User-friendly
display
Customers
have to wear
the shirt for
monitoring;
Noise by
movement;
~300
Vitaliti™ Cloud DX
(Xprize)
Actionable advice 355 (199
for pre-
order)
Ritmo
Beats
Nuvo Customer-
targeting
ECG and
acoustic sensors
Still under
investigation;
Unknown
accuracy or
diagnostic
value
250
PregSens
e
Medical user
targeting
130
7. Wristband
(Or using
by finger-
touch)
AliveCor
Heart
Monitor
AliveCor
®
AliveECG app
connected;
Convenience
AF detected
only (1-lead);
Practice for
good
conductivity;
74.99
Fitness
tracker
Samsung
Gear™
Fit
Samsung Curved 1.84”
Super AMOLED®
display
Limited
monitoring
function (heart
rate only)
149.99
iWatch Apple Micro-computer
on the wrist
Limited
medical value
(Watch)
399/599
/>12,000
Research
Kit
Large data
possible
conducive to
medical research
Unknown
benefit for
customers in
short term
N/A
Table 1. Overview and comparison of selected commercialized medical products on
the market
Apple watch and other medical app emerges
As one of the most press-interested news this year, launch of Apple Watch
and its ResearchKit seem to grab much attention and market share.
According to Apple’s advertisement and comments from many presses, the
ResearchKit targets more at help in revolution in medical study rather than
improving detection and monitoring of individual health conditions. Other apps
are still under testing and there is, no wonder, continuously deluged
complaints from customers. Moreover, the wristwatch itself has little difference
from similar products designed by other brands such as SamSung and
considering its personal health tracking function it is nothing more than a
fitness gadget. Yet overall Apple Watch has surged a revolution in
smartphones in attempt to compact high-tech within wearable products.
Besides, there is a common problem lying in those wristwatches, questionable
accuracy. When the measurement actually takes place at the wrist, customers
should never expect much accuracy from it not alone for doctors and
clinicians who would want useful data conducive to their diagnosis. Instead,
direct measurement in the chest is more beneficial with less interruption from
noise from other organs or signal transmission from the heart to the sensor.
Thus those are not potential competitors to our product even for its
remarkable sales volume, which mostly comes from admiration by its fans and
fashionable groups.
Wearable ECG products –can we really trust them?
Multiple versions of ECG-embedded medical devices are commercialized
every season. Companies spare no expense on promoting their products by
claiming the high-tech implantation and long-term benefits in their products.
They do work, but also perplex choices with so much overlap in their medical
8. value and diverse fancy exteriors. Furthermore, their actual medical or clinical
value might be not that remarkable even some might advertise that their
techniques are in a class of their own. In order to make comparison between
those current products and our own device, we just look into their core
techniques and target markets, and make a brief comparison between them.
We also make a tabular product review to make it easier for comparison with
our own design.
Accuracy and reliability concern
Emergence of wearable ECG devices for long-term monitoring and
measurement does not guarantee a perfect solution to the problem discussed
above when the abnormal sensations do not necessarily rise from cardiac
problems. Some products have already taken this problem into account and
make adjustment in design concept. Most of them attempt to address this
issue by embodying respiratory measurement in their devices. Yet the furthest
they can reach usually ends up with detection of respiratory rate rather than
other quantified measurement of real medical-value.
Another concern is that most commercialized ECG devices are equipped with
only one single-lead ECG from which customers or the clinicians need to get
all information ready for self-assessment or diagnosis (information like heat
rate and respiration, and etc.). Thus the reliability in such products remains
questionable, and it restrains diagnostic value of the products to an
indispensable extent. The justification of three-lead ECG we employ in our
device is illustrated later and relative testing has been proposed.
Emergence of vest/shirt-like products
An emerging type is the vest-/shirt-like product that may aim to realize the real
‘wearability’ in medical devices. ECG and other sensors are embedded inside
the vest where they can monitor and analyze instantaneous physiological
conditions by signal collection and programming while at the meantime, users
would not feel that they are actually wear something for such monitoring. In
another way, it seems that such products are easy to get FDA approved
compared with patch-like ECG monitors.
However, here comes the question. Much noise can be expected due to
intervention from other organs as well as that from friction or motion occurring
between inserted patch and skin since poor fixation is available here. There is
no reason to sacrifice efficiency to pursue increased wearability that should be
an add-on feature for medical devices.
There might be more concern about the prevalence and marketability of those
vest-like ECG-embedded products. Since the market is no longer limited to
the elderly, it is hard to expect all those who concern about their
cardiac/pulmonary conditions to wear something that makes them feel
confortable while look like a patient. Anyway, it is a phenomenon that even
9. aged people are more likely to care about how they are dressed, making
those products more difficult to reach the market as they might predict.
Our product combines multiple measurement methods and is able to collect
quantitative information of both cardiac respiratory events. Lung sound
detected and recorded with the microphone would add to higher diagnostic
value and together with the base station expected to be developed in the
future the whole system shall be superior to most other products already on
the market and offer more benefits for customers in no doubts.
Extension of market
Based on their market share and sales records, fitness products are mostly
targeted at young or middle-aged people. Those more diagnosis-centered
products, instead, hold their market mainly in patients with disease history and
the elderly.
Recent years have witnessed an extension of the market in both fitness and
health products as female, especially pregnant women, pay more attention to
their health and become a noteworthy part in the market. PregSense is one
among those and still under FDA investigation for commercialization. It could
a long way to go but may be worth trying since there is likely to be a
saturation in the market for them.
Our product differs in that we would not claim to target at any patients. Instead,
we try to help people to become the patients by predicting any possible
conditions risky to their health. More detail would be included in the business
plan.
FDA concern: lower the risk for customers
Due to increased market demanding for medical devices, FDA is taking
actions to slacken its restriction on medical devices if they could be justified
for low-risk. Yet no cue shows an easier approval has been granted on
cardiac monitors or any products with the purpose to give or help in diagnosis.
One important concern here is the false negative (FN) and false positive (FP),
which have already raised lawsuits between customers and medical
companies. Since the FN and FP can be hard to estimated with finite testing
and data, devices aiming at improving efficiency of diagnosis may find it
especially hard to get the ‘easy pass’. Conclusively, we cannot account for a
highly flexible standard or policy in the coming future to accelerate the
marketing of diagnosis-facilitated medical devices.