good afternoon everyone uh thank you for
being here for this talk today um I
remember being here at the same stage s
years ago and that has in fact been my
last talk uh ever and U so many things
on the way and this is the next
one um so I wanted to talk about uh a
project that uh we entered into the
2017 hackaday prize called healthy pie
it's uh open-source vital science
monitoring system for the for for human
vital science and uh where it went from
there what we ended up doing what
we uh what mistakes we ended up doing
and where we are
today so 2017 we had uh two projects in
the finals uh uh one was uh the first
one which was named as connected Health
later became healthy pie and the second
one was a wearable system called Hardy
patch um so healthy P won the second
price and uh hearty patch was selected
as a runner up for the best
product um so with two of these uh
Awards uh we we wondered what next I
mean people were asking us okay with the
price money are you going to celebrate
are you going to go to Disneyland and no
I said no I need to pay back all my
loans which I which we took out to build
these things so for us this
was uh a question of how to make these
into devices and sell them so in this as
far as the selling is concerned um there
are two things that we could do I mean
we got approached uh the hacker price
really pushed our ideas forward right so
we got
known um in a lot of different
communities and people started
approaching us uh most were investors
and I don't have any idea how to talk to
investors I'm not a business guy so two
two paths are available one is you
accept funding from whoever wants to
invest in you and the second was to just
still stay open and somehow manage to
sell devices and still stay alive and uh
we ended up trying both of
them what we did not do is sell the idea
to another company and because we were
sure that we still wanted to develop the
product on our own and also maintain the
open source nature of the
projects so with with with hearty
patch um so with hearty patch uh we
decided okay so let's let's just let's
explore the Venture funding route and uh
let's let's start making
devices
um so the problem with when you have a
device that is open source and you just
want an award and you go and ask people
for funding I mean let alone investors
even Banks uh first thing asked how many
patterns do you have and we said we
don't have any patterns so they said
then what did you build he said we built
this device and it works it gives
results but still they just har on the
no patterns issue second thing is uh
what this is this was a new term that I
learned after doing that it's called
freedom to operate and it the second
question we got asked is okay are you
infringing on any other patterns so we
said so far as I mean as much as we know
we are not but it's all out there it's
on hacker day everyone can check it out
and let us know if we are doing
something wrong and the last one was
finally we found someone who was willing
to
invest uh because the way that we saw
hearty patch was it was a variable
device which was ready for the market it
can monitor your heart rhythm in real
time it can detect different types of
arhythmia and all that so the natural
path that we saw was to take it to the
market because people started asking us
about okay how do I get one how do I get
one from my father how do I get one from
my mother so we did run a crowdfunding
campaign on crowd Supply but that was
quite limited it was limited only to
developers so we really thought that
taking it to the market would be uh
more
impactful
so yeah we found an investor who did
invest and so some of the pros and cons
of going to an investor is yeah of
course the obvious things are uh you get
instant funding and you get the funding
to scale but the cons are the we had a
certain change of culture that there
were no more sharing of designs uh every
meeting you went to had an India to sign
otherwise people don't talk to you and
um we are not allowed to talk to each
other either so it was kind of strange
for us because uh coming from an open
source um from an open- Source team and
integrating with such a thing was
difficult um so but we did succeed um
Hardy patch became a company called
patch um
based in we are based in
Boston um but uh I mean it was conceived
in Boston at least with one of my
friends and but we operated completely
out of our home base uh India and it is
currently being used we were successful
in developing a product um getting it
through I mean one of the main
challenges of making a medical Pro
device is getting through all the
regulations and the testing
which is probably the biggest cost year
we were successful in getting through uh
all the medical regulations uh um
including the FDA in the us but we
thought India would be a best place to
uh start so after this so so currently
it is available in the Indian market
although I'm not involved completely in
the marketing and sales which I find
kind of dull um and I want to stay away
from those people as much as possible in
order to uh avoid any more fights so um
so I'm so I I once the product was
delivered it was in the market and
people started using it I kind of moved
away
and and this is the story of healthy pie
so healthy pie also was in
2017 and this product we decide to keep
it open no no matter
what um uh again um the pros are uh
quite obvious but the main ones are
there's no lawyers involved I mean at
least not until now and uh we went the
crowdfunding route for this to make it
into a product because there's no point
in just making an idea if it's just
going to sit on the Shelf so we wanted
to go the crowd funding route and we
launched a campaign on crowd
Supply um the good thing about
crowdfunding is that you already have
your customers so you don't have to pay
to figure out who your customers are um
but of course the cons are the funding
is severely limited you have only a some
money way way lower than what you would
get from Venture
funding um and
and you always keep getting getting
asked the question okay how do you make
money well that's what I'm going to
answer and this I'm talking to you about
this the how do you make money part
because uh this is my full-time job we
run an open-source hardware company
called protoc Central Electronics based
in Bangalore
India
um so just a story of healthy pip
how it came to be and what it is now uh
how it came to be is in 2017 we thought
okay we were already in uh the medical
development field I mean my background
is in biomedical electronics and I have
developed uh medical devices before for
for various uh different companies
including the Indian defense uh and
everything so so this was kind of a
natural trans for me and in 2017 we
wanted to for with the first version of
healthy P we wanted to just prove the
idea that okay can you make an open
source a fully open source working vital
science monitor these are the same vital
science monitor that you find in near
the hospital bed or in the
ICU um so we proved that it could be
done um uh essentially it was a hat for
the raspberry pie and and it uses the
Raspberry Pi uh 7in display and um it
was able to capture ECG respiration spo2
temperature or any anything else that
you wish to add to
it um so so though that was 2017 and
that was called revision 3 I mean
although it was one revision one and two
failed so it's three is the one they
started with um and and
so uh so we ran a Crouch Supply campaign
as I told you and uh uh we sold quite a
few
devices and but still the concept was
that it was still a open source patient
monitor so so but people started asking
so what um but but still we had a lot of
inquiries for for example medical
education and even monitors in uh third
thir world countries uh we Supply to a
lot of countries in uh
Africa
um and uh even to some people who wanted
to build their own in war
zones um notably not recently but during
the previous uh Gaza conflicts some of
them are used for medical
monitoring uh so in 2019 we thought okay
why don't we just make it Wireless and
we called it unplugged and we ran
another crowdfunding
campaign um and this so also sold quite
a bit but in between we had to stop
mainly because the 2020 we had covid and
uh we had the shortage of components but
but incidentally we also reserved some
stock for covid research and uh I have
as far as we know at least five research
teams used it to monitor um covid
related
uh uh changes in the vital signs and
correlating that with long covid there
was this symptom called long covid where
the it just uh continued so so that was
used and uh then we ran out of
components so so we didn't know what to
do and people were still asking us I
mean how what are you going to come up
with and then we go decided to go for a
completely I mean we we we stopped
depending on most of these
uh uh highly integrated chips especially
from ti ti had a severe uh chip shortage
and uh we started making things
discretely uh like ECG amplifiers and uh
especially power SE power circuits for
some reason they all uh I mean some of
you might be aware that power integrated
power management I were all sold out and
there was no way to get them at least
not for us so so all that happened and
in this year we came up with uh revision
five uh revision five is based on an
rp240 chip which is our become our uh uh
favorite chip right now and uh and an
esp32 for uh radio and we also have a
new version coming up called healthy by
move um we call it move because it's a
variable version of this and that is
I'll be talking more about that with
hearty patch unfortunately I cannot
share anything about the evolution and
this is the problem right this is this
is what I meant
by keeping it open so that I can still
come and talk to you about this today so
the evolution was pretty much this we
had the hearty patch from the hack price
it goes into a black box and it produces
this device uh which is currently in the
market um I don't think my investors
would be happy if I showed what H
happens inside the
Box uh so so we ran three crowdfunding
campaigns on uh crowd Supply the latest
one uh ended uh uh in June this year um
that is almost after four four year uh
Gap we launched a new one and uh uh
we've been successful to some extent
although there have been a lot of
questions about okay will you be
delivering on time and uh is there still
any issues related to availability and
things like that but uh we're happy to
say that uh couple of days ago we sent
our first shipment to crowd Supply and
uh this should be uh delivered next
week um so this is the one
so again this is from a lot of different
features I'm not going to go into the
details but uh uh we decide to make it
into something that is actually F usable
um if people want a display they can use
a display or if
they just want to record stuff it can it
has an onboard uh flash memory for
recording days of data or they can be
wirelessly
transmitted uh so so I just wanted to
quickly go through some of what we
encountered again I'm not an expert in
product development but I wanted to just
show you what uh issues we faced during
the product development process
um first is listening to people who
would potentially buy your product um
this is we dropped the ball on this a
couple of times um we made something and
um looks like people didn't want it and
I'll go into more detail about that um
here the hacker day Community helped
quite a lot they came with a lot of
ideas and uh we integrated most of
them um and the rest is all uh
straightforward uh so yeah this is the
first thing that I said I mean listen to
your customers and
learn um and you will also be surprised
because sometimes you don't
know what ideas will come up these are
actually two comments that came
up uh on our crowd Supply page um asking
if they can buy devices to do this one
guy wanted to use it
for um he was a sniper and he wanted to
use it for measuring his uh heart rate
in the rate of
milliseconds um before pulling the
trigger before releasing the trigger
actually and he said can we use it for
that we thought okay we never we never
thought about sniping before but yeah
okay sure and uh that was that was quite
out there but I I guess he was
successful in doing what he wanted
because he wrote to us with a field
report uh the second one is I mean this
is just two of the ones that I picked
out of the lot of comments
and second was to measure arthia
apparently for cats I did not know cats
had arthia before um apparently they do
and uh cats have uh Rhythm issues so
this guy I guess he snapped it onto his
cat and collected some data and these
these people were two that actually used
it and who wrote to us uh about it so
you'll be surprised at uh what customers
come up with so so this is the power of
keeping it open source right I mean you
show what can be done and you get new
use cases for
it yeah and and
uh and the second um advice that I have
is freeer design early on uh unless you
want to end up with so many revisions uh
we had
5.0 uh which we never ended up send
sending it to fabrication then we had
5.1 and somebody asked okay um the SD
card we we sent it out to a few testers
and they said okay the SD card here
keeps falling out change it to a
different slot and we did and U I wish
we would have uh compiled all this in
the beginning to avoid so many
revisions and the others were related to
position positions of LEDs simple things
and uh somebody else wanted okay how do
you ensure Security in this uh device so
is there a um there are these chips
called secure element that are used to
store uh uh keys and so on so we added a
secure element where we store the keys
and that also does the encryption and
decryption so so that was added in 5.6
and finally we settled on 5.7 which
which was the one that we shipped uh
last
week uh some of our tools and uh our our
latest favorite thing to use is zeper
and uh almost all of our software is
based in on
zeper um yeah and
chips uh a little bit about the firmware
design uh I'm obviously I'm not going to
talk about the that ji was written in uh
processing which is open source
crossplatform easy to use and still
surprisingly powerful and for the mobile
apps we used
flutter um which is also surprisingly
powerful given that it's so simple to
use and it's crossplatform
um so flutter compiles natively on
Android and iOS but and there is no
interpreter involved so these are our
apps where you can monitor uh I'd be
happy to show some of these I have some
devices with me if somebody's interested
I can show it after the talk
and U yeah just a little bit about the
architecture because um I feel that
reusability of code is very important so
um so here we had a architecture right
for healthy Pi 5 we we had this kind of
an architecture where we have an rp240
on one side and uh which does not have
radio or Bluetooth and we had an esp32
C3 module on the other side which runs
both of them run zephir and one runs the
zeper uh controller stack the at the HCI
level it's called
H4 and
um and the rp240 just runs the regular
stack like almost as if it had um B
radio built in and this was pretty easy
to achieve and it's surprisingly fast
and it is low power so this was what
really made us uh closer to zepher we
have used zepher before in different
things starting from the days when it
was called it came from
minute but things were really difficult
at that
time um so again uh I I I don't work for
zir I'm not marketing zir but I just
wanted to show you that how it is uh
it's uh it's although it is uh
architecturally equivalent to Linux
kernel and everything it is surprisingly
high performance it's it's very high
performance compared to anything else
that we've done so what this means for
healthy pie is
uh um so we have healthy Pi 5 uh which
is the latest version uh it's got an
rp240 plus esp32 that I showed you just
now and we have a healthy P move which
is the variable version I have a
prototype of that also if anybody's
interested it's like it's a watch uh
kind of setup um and it also does the
same thing uh it's got ECG from um I
think I have a slide on that if not I
can explain it later but the cool thing
here is that we still share the same
healthy py code
base um and when I say share the code
base it's exactly the same except the
sizes of the screens it's exactly the
same and this the same code runs um on
rp240 as it runs on a NRF 5340 from
Nordic if you don't know it is it's got
two cores and and it's also we found out
that it's internally connected I mean
it's internally connected through
different protocols open amp and
everything but essentially it runs as a
HCI host and a HCI controller which is
the same thing that what we did so we
puted the same thing there and the same
code compiles and runs which is pretty
amazing in embedded systems because
things rarely work that way although
they say it's portable and everything
you still have something to
rewrite and um so this gives us
confidence and uh so we intend to build
more application specific versions maybe
the one for the cat um and future
versions just based on this code
base uh yeah uh this is what I said so
no pting um there are these uh DTS board
definition files which are very similar
to the DTs files and the overlay files
in uh in the Linux kernel and uh it's
pretty amazing that it's the it works
exactly the same way on an embedded
device as well and and overlay files
yeah we can use that to um compile
binaries native binaries for all of our
platforms from the same code base um
modular applications and the
applications itself can be modular in
fact recently I we tried out something
called uh zepher can load linked modules
at
runtime so which means that it can
actually load programs in runtime from
Flash and run it um which was pretty
amazing to us given that it's only an
embed system with a single
microcontroller um yeah another thing we
learned during the process of making
this production ready
um I've not gone into the details of how
we call this production ready but what
would be required to get your production
ready is to make sure you comply with
all the um environmental Emi EMC and the
basic requirements that are required for
a
c um or a ukca Mark um so this was we
have done this for hay patch before but
that was at uh but that was a different
thing because that was at a different
lab we had a a ton of money and uh we
just kind of outsourced that part uh but
here we had to do it ourselves um I mean
with a local lab um so the first picture
that you see is in anic chamber to test
uh the emissions um radio emissions
second one for ESD and then the third
one is for a line testing so this is
when you get surprised right
um so we take this board so we've
already reworked on this board so many
times so this is version 5.6 which is
what we decide to
freeze um as the final
board uh we were very confident we had
taken EMC considerations early in the uh
design itself but as we went along
through the designs we got so lost in
working on new features that we kind of
let it
slip um basic rules are yeah every
signal should have a short return path
to ground right I mean that's that's
almost the basic thing but as we kept
adding components we kind of lost track
of that and we go for our final
compliance testing and we see these two
nasty p
on the uh this is a I think this is a
horizontal sweep of uh 30 to 200 Megs I
mean um uh emitted
radiations which means that this failed
we we cannot ship this
device um so this happened because again
we went too fast we added stuff too fast
and uh we
lost um track of Emi my
guidelines so so yeah the lesson here is
yeah be ready for failures and fixes um
so what we did uh luckily there was only
one version in between from 5.6 to 5.7
we were able to fix those Peaks and you
can see everything is under control here
uh so what we did is we kind of ripped
up the entire board and relay all the
traces and um it's uh some people think
it's as as simple as
relocating a couple of inductors and the
Peaks go away they don't we tried that
they don't and uh we had to re uh um lay
the entire board and there are some
things specific to medical devices um
FDA whether it is in us or in India or
in other countries wherever you're from
um these set of I 60 601 D2 d there
there are a bunch of Standards which
have got observed naming
conventions um and then you get a
consultant and give him a lot of money
to tell you what to do but you can
anyway get asked a lot of questions
sometimes you'll get a question or we
got 48 of them which we had to answer in
3 months and for which for each question
the consultant charges this right so so
these are are some typical barriers to
medical devices and by medical
devices I mean if you're really
targeting medical devices for use in the
hospital uh crowdfunding may not really
work out so a quick road
map
um so we've come until healthy P 5 and
people have already started using it for
field research clinical research
applications where uh I mean we started
with the patient monitor concept and
where we ended up is uh produ this is
what we meant by production grade right
so it can be used in field applications
for recording human Vital Signs uh it is
certified so it has been used in a lot
of uh clinical uh research applications
all over the world um everything ranging
from uh we've seen we we've seen the
most common is cardiac studies and
everything and also
where you put all these Vital Signs
together and there was a recent
challenge about can you actually detect
septic shock using this so we we we
demonstrated that we can actually run a
small uh machine learning model on the
device uh we used Edge impulse uh this
device now supports Edge impulse with a
native API for that so
so we can collect the data push it to
Edge impulse and and uh take the
resulting model and put it on here to
run uh the tens oflow model uh this is
all possible because of and this all
works on the
rp240 um and the one in yellow is the
one that we're working on right now
healthy by
move uh we some of some of the questions
we got asked from the people who have
used it for field uses can you make one
that is varable and still collect all
the data that is being
collected um so we took on that
challenge and
uh uh this is a watch based device I
mean I have a prototype if you want to
see um so it it doesn't calculate heart
rate from PPG because the from the
optical um pulse rate because there are
known uh in consistencies between them
right so so this uh Records ECG from uh
similar to how all these commercial
smartw watches do they have two
electrode pads that touch the um and you
take the second thing to Second uh hand
and that gives you a left arm and right
arm configuration and that gives this
kind of an ECG Peak um and we were able
to successfully filter that out to give
uh this
quality um and it's also got spo2 but um
we're not again the SP2 that we get from
here is not accurate and there are a lot
of studies to prove that so which means
that the commercial watches cannot be
used for clinical studies so we are
actually running a
device a small PCB up to the fingertip
and collecting data through uh through
an ice sare
interface and using the ECG and PPG we
also calculate blood pressure Trends not
not not absolute blood pressure but uh
the variations in blood pressure over
the clinical trial or this how however
long the study may be um and
temperature um so again it's the same
code base we're building on top of
it um a quick summary uh
yes it is possible
to take both
paths um although taking it from an open
source uh I would like to remind you
that that's the original hearty patch
design is still open source it's still
available on GitHub and it's still
available on um hacker it's just that we
are not making and selling them anymore
so instead we are making and selling
patch um crowdfunding is a a very
sustainable way to raise
funding um and of course winning the
hacker day price was much more fun than
writing business plans and I really
hated that um so and listening to
customers but uh all said and done right
now um I I've told you that we we we
finished our commitment of uh getting
hearty patch to the market so after that
I uh have a back seat and I'm back into
working full-time on Open Source
Hardware um and that's where I planed to
be um and also things like zeper and all
the new tools that come up make Hardware
much more accessible than it was before
7 years ago building something like that
with a Nat Mill uh chip was quite a
challenge now it doesn't feel like a
challenge anymore which which is kind of
disappointing in a way that it is uh
it's not a challenge right so but but
still uh makes things
easier and uh yeah listen to your
customers unless you want to spend a lot
on multiple prototypes I
think yeah that's my talk and uh you can
you can write to me if you have any
questions and I'll be around and that's
our crowd funding Campaign which is is
now closed but um it'll be available
soon
thank
[Applause]
you so I think I finished within time so
if I have some time
for uh questions I can take
them
no
yeah yeah yeah yeah
yeah yeah no I still yeah I'm
sorry
experience um I'm still running a
business right so so this Open Source
Hardware business is is also a business
although you keep getting asked okay how
are you making money is this a charity
and all that but uh but in the end
people still buy these uh devices so so
my experience is is
that I mean in in Open Source Hardware
and with crowdfunding especially you get
to answer to your customers which is
which is much more um straightforward
and more fun than answering to investors
investor meetings are dull right so um
so I think that way uh coming back to
open source has
been um
it's a shock in a little bit uh in a few
ways because um you're suddenly faced
with
okay funding wise you're back where you
are and uh and all that but uh so we've
been we finished anti Pat all the
development last year so it's been the
second year we're back into open source
and healthy P 5 is the result of
that
okay so is your hard
yeah
yeah so here in the road map I forgot to
mention that on healthy P 5 we' we've
created a modular system so you get to
add more stuff right so EMG is for
electromyography GSR for for studying
emotions and stuff like that and EG for
uh um for for uh brain wave activity and
and we have been doing a side project
now that we are open so nobody asks us
question so we've been doing a side
project on uh brain computer interfaces
using healthy
pie uh in fact one was uh a recent thing
that we helped out a student team uh
they made a brain I mean an easy
controlled wheelchair for uh for people
on
processis yes so let's say someone wants
to build um some application that is not
open but they want to use your for do
you see something like work poti
or say you have a platform but then
someone wants to build something very
they don't want to like they want to
build a business in
non can that combination work in your
opinion yeah yeah I mean um if they want
to take a healthy Pi five and this has
also happened before people have taken
healthy Pi not the not the five the
previous
versions and built their own product
around it and sold it I mean and and the
and we follow the licenses that I forget
which license we we keept updating the
licenses but um um we make sure that
this these are not restrictive licenses
because uh as long as it grows it grows
I mean we don't restrict uh that it has
to be open-
sourced unless there are any other
software components that are distributed
under GPL or something like
that so yeah there's no restrictions and
people have used it and people have also
asked us can you do small modules I mean
right now if you see most of the patient
monitors that are coming from Philips
and G and everything they are all based
on one OEM module which takes ECG
respiration and spo2 and they plug it
into their uh patient monitors and that
pretty much poers everything which is
there so people have asked us can you
make something like that and provide and
we said sure I mean if that is a real
requirement then we can make OEM uh
modules but but these o modules you can
also tune the software according to your
own
applications one one very common issue
that we Face always is uh people coming
back to us saying SP2 is not accurate
now for those of you who have worked on
spo2 and PPG
devices um SP2 is a very it's it's not
as straightforward as ECG where you see
the Peaks measure the Peaks measure the
timing SP2 is kind of like a a
derived uh thing it's more of an
empirical uh calculation so if you
really want to I mean now the best way
to validate an SP2 device is only
compare it against another device uh
that's the only thing that's available
right now there is no measurement of
intervals no meas mement of amplitude
nothing so so if they really want and it
also varies according to skin color
right so what that we calibrated on the
Indian population may not work here so
that requires something called a breathe
down test where you get a bunch of
subjects in a room and ask them to hold
their breath
until until they don't die I guess and
uh and then measure and for even lower
perfusion um lower blood flow lower
perfusion things that mainly happen
during covid the testing is even more
rigorous but yeah you do compare against
some other device called the gold
standard
so
yeah okay anything else yes do you use a
feature of zeper that lets you update
your product in the field yeah yeah yeah
we of course we use MCU boot um which is
the main Bootloader for this and we use
uh uh uh the dfu is done through uh
Bluetooth or USB the Bluetooth has the
smpp service which is very well
supported in zir and it's very reliable
also and the addition of the secure uh
element which is used to store the keys
makes it more uh secure as well makes
MCU Bo more
secure um I mean it's getting better
every day I mean recently zeper 3.5 was
released and it was it really took me
back so
yeah thank you
[Applause]