Posted 02/06/2015

Community Update 2: The twists and turns of a washable cover

It’s been a month since our last update and we are excited to share with you our progress from the past four weeks.



This week we received the latest version of our Wi-Fi + BLE module (see image below), which contains a broadcom chip and all the components to make the radio work.

The blue object is a built-in antenna and the round piece is a connector for an external antenna. It’s relevant to highlight the FCC logo printed in the module, which means the component is pre-certified.



Remember when we shared with you a first look at how our sensors were picking up a sleeper’s heart rate? Well, we have made a lot of progress since then, in testing and refining our filtering algorithms for accuracy. This required comparing the performance of our sensors to that of other medical health-grade sensors and products in the market.

What were the challenges? Most medical health-grade sensors and products that we have been using to compare our sensors with are not designed to be integrated with third-party software, so we had to do a lot of work to have them play nicely with our data collection.

What is our progress? We have been gathering movement, heart and respiratory rate information from both our sensors and health-grade products like an accelerometer, an ECG, and a pneumograph. We have compared several data points and it is looking like our sensors and algorithms, when compared to health-grade technology, have a very comparable level of accuracy in movement detection and they are relatively close in heart and breathing rate detection (see images below).


Here is an image of Massimo’s (our CTO) heart rate and breathing rate at rest extracted from the piezo sensor signal in the Eight cover.


Readings of the heart rate signal.


This is great news, because we can still optimize the filtering in our algorithms and have our own sensors’ readings be even more accurate.  It is a great achievement for product development, and we can now iterate on the data analysis software and measure how much we are improving and how scientifically accurate we are when compared to devices that measure heart and breathing rate through direct body contact such as the pneumograph and ECG. We expect to keep refining and improving the quality of our data and provide reliable metrics by the time we will ship. During an upcoming beta test we also want to run comparative tests supervised by sleep physicians at sleep clinics.

The next step in this is to collect and classify a lot of data samples from different individuals, and automate accuracy testing of our algorithms on all the data samples.



As we mentioned in our last update, the smart box is a key element of the whole Eight system, and it will serve certain functions in communicating different queues to the user. In our previous update you got a glimpse of the light behavior and how it is already working in conjunction with the Eight app, but the final placement of the light was still pending.

What were the challenges? The industrial design of the smart box was practically done since our last update, so the challenge now was to include the light placement without disrupting the ID, but still ensuring that we were accommodating enough to have a light behavior that serves its function while looking elegant and seamless in any room and over any type of surface. Our mechanical engineers and industrial design team spent the past weeks working on this leds placement and testing all the options, until finding a solution that works well and looks nice.

What is our progress?  We have completed a new version of the smart box that displays the final setup for the lights, and also the venting. You can see this new iteration in the pictures below.

A Luna Smart Box prototype placed on a night stand.

An Eight Smart Box prototype placed on a night stand.


The Luna Smart Box with the button pressed down and the light on. On the right, the light shines in a darker room.

The Eight Smart Box with the button pressed down and the light on. On the right, the light shines in a darker room.



The bottom part of the smart box prototype, showing the ventilation holes.



The smart box prototype placed over the cover.


We are really excited by this, and we are moving on to outstanding decisions on the smart box which are related mainly to user experience: light colors, button behavior, etc. This puts us on the right track to lock down design and move into the next stages of prototyping and testing.



Manufacturing a mattress cover might seem easy, but the reality is that there are a lot of small details to keep into consideration. One of these details is the fit of the cover, as every brand of mattresses is different – even among those of the same size. There is no standard that guarantees 100% proper fit of a cover or linen, which makes fabric selection even more challenging.

What were the challenges? When we began working on Eight we tested many of the existing heating pads in the market, and we found that one of the most recurring problems is that after a couple of days of use the fabric ‘gives in’ and becomes loose. When the top fabric feels loose it begins to bulk up under your fitted sheet and that is definitely not a nice feeling to have. When selecting our fabrics we have been extremely focused on avoiding this issue. This means that we must find a side fabric with the right elasticity so that it can fit on different mattress brands, but also that it can keep the top fabric firm and tight. In addition to this, the fabric must be high-quality and cost-effective.

What is our progress?  We completed a new iteration of the cover in which we tested and found a new side fabric with the right elasticity. We tested this new prototype in several mattress brands and have found it to be a great fit and feel for all sizes and brands.



A bedding product is a delicate product, because it is set in an environment that is personal and very intimate. We want to deliver on the promise of a cover that is just like any other cover, and that means it should be washable. Before launching our Indiegogo campaign we had run successful tests on the washability of the sensor strip, but the more and more we test on this the more concerned we get about the durability of the product after a few first washes, for the reasons highlighted below.

What were the challenges?  Making a washable mattress cover that has sensors and a power management box in it is quite a challenge. We always knew that the sensors and electronics could be waterproof, and we designed and tested for them to achieve that. The bigger issue though is the stress under which the sensor strip comes when being washed in a regular washing machine. The twisting and tumbling of the washing machine presents a real threat to the sensor strip, because the sensor strip is long and can get tangled and eventually break.

What is our progress? We have continued testing the washability of the sensor strip to mixed results. We have seen that after 10 washing cycles the sensor gets damaged enough to present a threat to the product’s performance. So we are now seeking a seamless solution that doesn’t compromise the functionalities and look of the cover but that it also makes it washable.

One solution we found in conjunction with our industrial designers, is to design the cover so that you don’t have to wash the whole thing but rather just a top fabric layer.

During the past weeks we prototyped a new version of the cover in with the top fabric is removable, allowing you to wash the fabric without washing the sensor and electronics. We have prototyped several versions that allow for a removable top: attached with buttons, clasps, or one zipper. We need to continue testing the different options but so far the zipper alternative seems to be the most seamless, convenient, and aesthetically pleasing, while serving its function and achieving the goal of having a washable cover (see image below).


The top fabric attached to the rest of the cover by an invisible zipper.


The top detachable and washable fabric, when unzipped at one corner.

The top detachable and washable fabric, when unzipped at one corner.


Now we are going to get a little more technical with other updates on achievements in our software and firmware.



We have finally completed the design and build of our development board, with all the devices of the final product. It took us a month from idea to final version of the board, so we are very excited to have it finally in our hands. Having our own and final development board allows us to write the entire firmware in parallel with the development of the hardware product, and particularly without having to carry around a mattress cover with us all the time! This should help us to run faster on the development of the software, and test more in details the algorithms and data analysis.

What were the challenges?  The electronics in our development board are quite complicated, and we had to build into the board some additional devices to be able to measure the effects of the behaviors of the firmware. As we mentioned before, it took us a month to get the final board in our hands, and we even had to source separately the final version of the wifi chips from a taiwanese company.

What is our progress?  We just received the final development board (see image below). The board is a very flexible development platform and has a lot of power (runs on an ARM Cortex M4 168MHz). It has all the sensors of the final product on board (except the biometrics sensors which are being tested separately). It also includes an SD card slot for test data logging. Now we have to test the board and all of the devices to make sure that the hardware works as it’s supposed to and include support for it in our toolchain.



We have made our firmware cross-platform, which means:

  • We implemented HAL (Hardware Abstraction Layer)
  • Wrote C drivers for all the final product peripherals integrated with HAL
  • Made our toolchain cross-platform

This means that we can continue implementing features in our firmware and test them with earlier versions of the hardware without having to re-implement them for the final product.

What were the challenges? Our toolchain is very complicated and depends on software provided by different manufacturers. It’s not a trivial task to get our software to work the same on hardware versions that have very different specs.

What is our progress? As we have achieved this compatibility, the next steps are to improve our toolchain even more and implement versions of the HAL for specific hardware platforms.



We have integrated a popular C unit testing framework (cmocka) into our firmware. This allows us to run automated testing for the embedded software of the product, to render development faster while keeping it at a very high quality standard.

What were the challenges? It is highly uncommon for firmware to be tested this way, but it is a technique that we imported from backend software development and it implied designing our own strategy to do it.

What is our progress? We have fully integrated this C unit testing framework, and now we must implement unit-tests for all the drivers and integration tests for the high level product features.

We’ve made a lot of progress on Eight – But we also need a little more time

As you read in our update, we have been hard at work building a product that delivers the best customer experience: from fabric selection and testing to firmware and hardware iterations. Eight’s experience is seamless and we want to ensure the Eight cover you receive is the Eight cover you were promised, with no sacrifice in functionality, reliability or look and feel. So we want to be upfront and tell you that we are behind schedule.

There is one main reason for being behind:

  • The sensor array structure in the cover is less durable in washing cycles than we originally expected.

During our testing over the past weeks, we found that the very aggressive washing cycle (i.e, washing the Eight cover in a washing machine) stressed the sensor array in the cover. This added stress over time could prevent the sensors from functioning properly and even make them break, which would affect the tracking power of the product. The washability of the cover is a critical part for moving forward with the manufacturing process and therefore we made the decision to extend the shipping date and get time to fix this properly.

In this case, the decision to find a better solution to the washability of the cover was placed above the delivery schedule to ensure the highest level of product quality.

Here is a table showing the original and updated shipping dates for Eight. In the table you will see two groups: people who purchased the product during the Indiegogo campaign (from January 27th to March 26th) and people who purchased after the campaign ended (from March 27th forward).


If you don’t remember when you purchased your cover, feel free to email us at [email protected] and we will look it up for you.

We know this news is disappointing and we apologize for that, but we value our supportive community and want to bring you the best Eight cover possible.

We are taking key steps to find a better solution to the washability issue. In this blog post we show you an alternative solution which we have prototyped already. The new washable solution of the cover has a top fabric that is removable, allowing you to wash the fabric without washing the sensor and electronics. We have prototyped different versions of this new design for a removable top, including an attachment with buttons, clasps, or one zipper. We need to keep testing the different options but so far the zipper alternative is the most seamless, convenient, and aesthetically pleasing, while serving its function and achieving the goal of having a washable cover



Over the past weeks, a lot has been happening at the office – and outside of it. Among the many happenings of May, we completed the three month program at Stanford’s StartX accelerator. We were happy to have learned from the amazing community of mentors, advisors, and fellow entrepreneurs. Take a look at the images below for a sneak peak into how things have been going for the Eight team:


Matteo, Eight’s CEO, presenting at StartX’s investor mixer on May 21.



Designing a smart a mattress cover means that we get to make beds very often.



David testing the latest sensor array prototype at our office’s demo room



There is not a lot of time for taking naps around here, so the product just watches over us.


Regan testing different lamination solutions to improve the cover’s washability.

Regan testing different lamination solutions to improve the cover’s washability.


Our software team at work.

Our software team at work.


Wrapping up, we are sorry to announce the delays in the shipment of your Eight cover. The team worked hard to meet the original schedule, but we just could not get it done without sacrificing product quality. However, please rest assured that we are making good progress towards production. Thanks, as always, for your support of Eight and please reach out if you have any questions or concerns.


The Eight Team