“Wanjiku” Ventilator Do it yourself (DIY) using a Direct Current (DC) Motor

“Wanjiku” Ventilator Do it yourself (DIY) using a Direct Current (DC) Motor

For construction of the “Wanjiku”ventilator using direct current(DC) motor we need:

  • A piece of wood
  • A hinge
  • A dc motor bracket
  • Apiece of “shock absorbers”
  • DC motor.

Assembling the parts together:

  1. Cut the wood in two pieces as desired to make the pressing arm and the base of the ventilator. 


  1. Hinge the pieces of wood together one side.
  • Cut a piece of “shock absorber” and place it on the wood as a base for the Ambu bag.
  1. After assembling the parts together:

For rotating the dc motor we need to connect the Arduino circuit.

The components required are as follows:

  • Arduino Duemilanov
  • DRV8871 dc motor driver
  • Potentiometers
  • Breadboard and Jumper wire
  • 12v 2A Adaptor

The DRV8871 device is an optimized 8-pin device for driving DC motors with 6.5 to 45 V and up to 3.6- A peak current. Check out its data sheet for more info: http://www.ti.com/lit/ds/symlink/drv8871.pdf?&ts=1589266356250

The electrical connections are as shown in the circuit diagram below:

Connection description:

  1. PIN 1 and PIN 2 from the driver connected to red and white terminals of the dc motor.
  2. The blue wire of the motor to Arduino 5v, green to ~3 of the Arduino, Black to the GND of Arduino and yellow is open. 
  3. IN1 and IN 2 pins of the driver are connected to the pin 8 and pin 9 of the Arduino.
  4. +VE and -VE of the driver connected to power supply.
  5. Vm and GND pin of the driver connected to Vin and GND of the Arduino. This is used to power the Arduino board
  6. The wipers of the potentiometers connected to pins A0 and A1 of the Arduino. The other two pins of the potentiometer to 5V and GND.

Here’s the Arduino circuit connection diagram:

The total Cost of assembling the ventilator is less than KES 20, 000 .

For commercial production or incase one needs us to assemble the ventilator for them you can reach us on below contacts

“Wanjiku” Ventilators

The stark reality of the COVID-19 pandemic has exposed the cracks in health care systems to adequately provide support to the affected patients. 

We realize the importance of ventilators as critical for the care of people with lung failure, one of the complications suffered by patients with severe COVID-19 attacks. The scarcity of ventilators is worsened by the fact that hospitals have to reserve ventilators to treat non-COVID-19 cases such as heart attacks, strokes and other emergency cases even at this time of the pandemic.

While we appreciate that the time at hand is not adequate to develop a fully compliant ventilator based on the government specifications, we believe that developing a low-cost portable automatic respirator with minimum features available to Wanjiku would save lives. Among other features, the machine should have invasive and non-invasive feature, and supports 400-700 mL tidal volume, with a continuous working capability for 2-3 days. Furthermore, any innovation must be attentive to the needs of the larger group of the population as opposed to the few. 

To tackle this imminent shortage, at DewCIS we envision a simply home-made ventilator, a mechanical breathing device that is able to blow both air and oxygen into the lungs. Rather than reinventing the wheel, our innovation is to reuse locally available parts to assemble a ventilator. Our vision is to empower every homestead to own a ventilator at minimum cost, using a simple one-page instruction DIY manual.

The device is made of an automatic motor pulling a tough string pulley tied to the board, which then squeezes the bag-valve mask, often called  ‘Ambu Bag,’ used for resuscitation in emergency situations, to push oxygen and air into the lungs.

 Assembling “Wanjiku” Ventilator, I Prototype

The device can be assembled from locally readily reusable parts, and consumer off-the-shelf components

Motor & Motor ControllerA basic direct current (dc) motor with 7 kg torque is preferable. A car wiper motor would do. The motor controller gives the various modes of operating the motor. 
Tough string1-meter long tough nylon string, easily available from a used clothe
Bag-valve maskoften called  ‘Ambu Bag,’ used for resuscitation in emergency situations, available at local chemists 
12V direct current (dc) supplya car battery would do, an old computer power supply module or an adaptor for the 240V alternating current (ac) supply
Arduino MicrocontrollerSupports programmable features of the apparatus. 

Other parts including casing can be crafted at home or from local jua kali kiosks.

This Wanjiku ventilator is portable, and therefore adoptable in villages and other low cost residential areas without reliable power supply, and is inexpensive enough to scale up in bulk production. In dire situations, an ingenious 4-way valve splitter can be used to serve upto 4 different patients.

Future models & improvements

  1. Craft a more durable base and casing to offer sturdy mechanism.
  2. Introduce gears and pulleys for a smooth air flow and eliminate jerking.
  3. Program the motor motions to allow supports of a range of tidal volumes.
  4. Include user interface to allows selection of preset inspiratory:expiratory ratios.

Physical Exercises To Do During Isolation While Keeping Social Distance

We are creatures of habit in what we eat, where we work, what TV shows we watch, when we work out etc. Right now with Covid-19, all those habits have been shoved out of the window. The extensive social distancing policies put in place to limit the spread of COVID-19 means most people will have to spend much, if not all, their time at home.

With new terms as “keeping social distance “, gyms have closed their doors, but does that mean we stop exercising and keeping fit? Remember one of the things you should do to fight this Covid-19 monster is to be physically fit. So, as we still keeping our social distance and quarantine ourselves, we can still exercise and maintain a healthy routine.  Here are a few exercise routines you can embrace and practice.

Take a walk

There are a million and one benefits of walking, which have, long been documented, this benefits include reducing the risk of heart disease, strengthening bones and muscles, and improving your mood according to medical gurus. Walking just for 30 minutes a day can make a difference. 

There is a question of how to take a walk while still maintaining social distance? Well that should not worry you if you follow simple instructions of keeping a six-foot distance between yourself and others and also wearing a mask as you take the walk.

Stairs climbing 

Using the stairs is an extremely time-efficient way to maintain fitness, and of course it’s free. If you live in an apartment with lifts, how about avoiding that uncomfortable lift encounters with other self-isolating neighbors by using the staircase for any necessary outdoor journeys. While at it, take care to avoid much contact with handrails.

Online exercise Classes.

Take advantage of the wealth of online exercise classes. Many of these are free and can be found on YouTube. With the quarantine and social distance directives, we can create our own gym through YouTube, with over a thousands of exercise videos available online. Since so many of us have smart TVs these days, one great way to build a library is to save a number of workouts into playlists you can easily stream onto the sets around your house.

Make sure to gather workout clips that cover the whole body: upper body workouts, lower body, abs, butt, cardio, strength, yoga, balance, flexibility and stretching.


Dancing is an excellent way to protect your heart lowering anxiety, reduce stress, and increase your flexibility amongst other many benefits.

Dancing also has established mental health benefits to help us cope with the coronavirus-imposed solitude. We can all agree staying at home weather working or not with this pandemic can easily stress and break anyone, even the strongest.

That said we can use this isolation time and experience the magic of music whether its reggae, Rock, local music which ever floats your boat, it will not be difficult to turn up the volume of your stereo a little higher and turn your lounge or kitchen into a little dance hall and lets dance the COVID-19 blues away at home like nobody’s watching.


With the Covid -19 crisis almost every one has been left worried, stressed and lonely with no routine. There is no better time to start practicing yoga.

It can be practiced in the comfort of your own home, at any level, regardless of how silly you may feel.

Doing Yoga on a regular basis can be extremely beneficial for your flexibility, help you boost your strength and improve your overall fitness.

With a focus on self-care, deep breathing, meditation and exercise, yoga has proven benefits for both mind and body.

Setting aside time for yoga also provides routine in your day and gives your mind a break while working from home.

Total beginners or experts could follow YouTube Videos, or purchase a book of yoga poses to work from.

Music Is The Universal Language Of Mankind

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There is always Music playing at DewCIS

.. We do this because Music has the power to quench mental anguish; is a form of art, which is universally accessible and has instantaneous effects on our minds. 

One time, when eavesdropping on a conversation of two colleagues discussing why he listens to Reggae, I found his response reaffirming at the least “ that Reggae cleanses from within and helps my mind achieve new potential, unlocking unlimited resilience when writing software codes.” His view was attested to by the ancient Hindus who believed that suffering caused by man’s uncontrolled thinking could be soothed by music therapy.

Expressive musical activities, often visible amongst some colleagues in the office singing along to streaming music, enhance the positive self-image and improve coping skills. Visibly so, because singing is a unique exercise calling upon our concentration, meditation, and breathing exercises all taking place unconsciously and simultaneously.

Nevertheless, listening to music of different genres and musical patterns affect the brain in different ways, firing disparate rush of emotions and behavioural patterns. Study has shown that listening to classical music can expand ones spatial reasoning, while listening to jazz helps with stress management. Traditional rhythmic music including chants, stringed instruments, drums and horns are very relaxing, appealing to our spirituality when played moderately loud.

Heavy metal music is great for reducing negative emotions and regulating anger and depression, especially among teens seeking validation for belonging. Avid listeners of rock music on the other hand, believe in its ability to enhance creative thinking. Listening to the sounds of nature has been shown enhance cognitive function and concentration; it is no wonder writers take time away into nature to craft their stories.

When all is said and done, music needs a mind to appreciate it. The material essence of music is found in its melody, harmony, rhythm, and dynamics. Melody gives music soul, while rhythm blends the expression of harmony and dynamics with the tempo of the beat to create a recognizable pattern.

Take a shot for those who love the sounds of the beat and be blown away by the dancing waves generated using the new revolutionary ambisonics recording technology sampled here https://www.youtube.com/watch?v=pwNDNuC5XsQ.

But again, for those who love quiet, continue listening to the sounds of silence like the beats of your heart punctuated with the clatter of the keyboard produced by your dancing fingers. It’s all music!

Use Of ICT To Enable You To Work From The Comfort of Your Home.

We are so much used to waking up every morning, getting ready to go to work. Nobody knew that a time would come when we would all be forced to stay at home and work from there. Many were confused on how, we would be able to work from home especially when we are all working in different fields. Thanks to Google, all answers that we need are there. There are so many tools that we can use while working from home to accomplish the same goals that we try to achieve everyday while going to work. Some of these tools are discussed below;

Stable Internet

Stable, strong Wi-Fi at home is an important thing at this moment. A reliable Internet connection is no longer a frivolous wish, but an increasingly necessary tool now that so many employees are working from home.

With stable Internet You can check email without delay. You can go to websites and not run into unexpectedly long loading times. A stable connection is a lot like a road without traffic. With unstable Internet you could lose out on potential customers, miss important emails, or slow your employees’ efficiency down to a crawl.


Imagine you walk into your office in the morning and the first thing you do is check your emails. What makes it different while working from home? It makes it easier to communicate to clients and colleagues via mail as compared to making a phone call or sending a text message. Unlike other forms of communication, emails are more reliable when it comes to passing official communication to people. They can easily be accessed at the convenience of the recipient and are not bias to the time of day that one should send an email. It’s also fast to send official documents via email since just clicking a button does it. Emails also are more economical to use since one only spends very little to communicate.

Online document filling

We fill documents in order to store vital information for future reference. It becomes hard to fill these documents manually while working from home and send them to relevant people on time. While this is the case, filling these documents online is the easiest and most effective way of storing information. It saves on costs of printing and filing, the information is safer online since its free from loss, the information can be easily retrieved by just clicking a button and it also saves people time by sharing the document to as many people as possible using emails. 

Online accounting to enable generation of Quotations, Invoices and Receipts

Most of us think that it is only people who are in the field of IT are able to work from home. Coming to think of it, technology has not only advanced in the field of IT but it cuts across all fields accounting being one of them. There are many existing online platforms that enable the generation of quotations, invoices and receipts among other things entailed in accounting. These tools can be accessed by anyone across the globe so long as they are connected to the Internet.

Online meeting applications –Zoom

The sudden and unexpected coronavirus, or COVID-19, pandemic has had a drastic impact on the way people work in just a few months. Many organizations are relying on technology and application such as a Zoom to allow their employees to work remotely and stay safe.

Zoom is the current go-to videoconference platform, and has the best video webinar functionality. It also allows users to record meetings and has group collaboration capabilities. Users can create groups and instantly send text, image, or audio files to the members of those groups.

Online and Integrated payment Mpesa and online banking system

We are very fortunate to be living in the era where Mpesa has become the norm instead of using paper money. This has made businesses work more efficiently since one can send money through Mpesa to purchase a product regardless of where they are. Many online platforms that people use to sell and market their products have integrated payment through Mpesa, which has increased security of the money and has also made businesses grow at a very high rate. Online banking as another feature of transferring money, has saved so many businesses since one doesn’t have to go to the ATM in order to purchase a product. Both Mpesa and online banking system are very useful in enabling people work from home in a more efficient and effective manner.

Cloud hosted business applications

Just as the name “cloud” suggests, these business applications can be accessed from anywhere so long as one has Internetconnection. What this means is, even while working from home, one is able to use these applications to grow their business and share information with fellow colleagues and clients.


As an organization we have had first hand experience with most of our employees working from home and we can attest its experience, which has given us a whole new perspective.

Being an IT firm we can help your organization set up all the tools discussed above and enhance your employees to efficiently work at home be productive and observe the much needed social distance as we fight the Corona virus