Enhancer mask lite

Description

The mask constantly records the biomedical data of the wearer and, if necessary, supplies medicine, neurotransmitters, stimulants, etc. via a syringe pump, which is absorbed by the skin via a carrier substance, for example, dimethyl sulfoxide. The mask is also equipped with a head-up display, a CO gas sensor, an ultrasonic microphone, a voice changer, and maybe more.

Details

Introduction

A cyborg is a living being that has been technically supplemented or enhanced. It is thus a manifestation of human enhancement. This serves the increase human possibilities and increases human efficiency and thus the improvement and optimization of humans. Furthermore, by my own definition, a cyborg must have at least one bio-feedback in both directions that provides the cyborg with a superhuman ability. I have chosen the head and thus a mask because most senses are located in the head and almost all important biomedical parameters can be measured at the head. Secondly, man has been using masks since the beginning of mankind. The oldest mask found is about 11,000 years old and comes from Israel. Remains of stone or metal masks were found - but drawings show that less durable materials such as cloth, plants, feathers, leather, or papyrus were also used to make masks. Masks are worn for very different reasons. For example, in the days before plastic surgery, masks were the best solution for veterans with faces scarred by war. And last but not least, almost every superhero or superheroine wears a mask.

Design starting point

To avoid complex design and high 3D printing costs, I decided to use smartphone VR glasses as the starting point of the design. These are cheap, mostly made of ABS, and therefore easy to modify. First, I removed the optics and all unnecessary parts. I will salvage parts of the optics later.

The mask could look something like that:

To attach something to the VR glasses skeleton, I designed two identical mounting brackets and had them printed using the SLS process. I'm not quite sure yet, but I think I'll make the rest of the mask entirely out of PCBs.

Syringe pump

For the second prototype of the enhancer mask, I do not use a peristaltic pump, but a syringe pump. The peristaltic pump has three disadvantages: There is no feedback like a rotary encoder, you need an extra container for the medium and the pump is quite heavy due to the relatively large gear motor. All these disadvantages are eliminated by the syringe pump. For this reason, I have designed a mini syringe pump that uses a 5ml syringe. It consists of the following components. The white parts are laser sintered and made of PA12.

The syringe pump works flawlessly and I'm pretty happy with the design.

Of course, the pump needs a motor driver. Since the motor spindle already rotates quite slowly, PWM is obsolete. However, the motor must be able to rotate in both directions. My choice has fallen on the BD6736FV. The single H-bridge driver works with a motor power supply voltage of 2 to 9V, the same for the logic. Since I want to use a 3.3V microcontroller and 5V for the motor and the logic of the motor driver, level shifters are necessary. The bidirectional level shifters are a little overkill because INA and INB are just inputs. Two voltage dividers would have done as well, but this has the consequence that you can't change the power supply voltage so easily anymore.

The PCB is mounted directly under the pump and therefore has a special shape.

A stencil was used to populate the PCB since the BD6736FV has an SSOP-B20 package with a pin-to-pin distance of only 0.65mm. The slider pot will be soldered after testing.

Since there was no magic blue smoke during the function test, I mounted the PCB below the syringe pump.

Optics

I still like the idea of using a transparent OLED as AR glasses. However, we need a lens if we don't want to mount the OLED 10 to 15 cm away from the eye. Since the salvaged lens of the VR glasses is predestined for this, I have designed an appropriate bracket that holds the lens, the OLED, and the associated circuit board. The bracket was printed using the SLS process and dyed black.

The plan is not to place the optics directly in front of the eye but to turn to the side so that you only look at the display when you turn your eye to the corresponding side....

Project Logs

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Extended hearing

M. Bindhammer • 05/17/2023 at 14:59 • 0 comments

Humans can only perceive sound in a frequency range of 16 Hz to 20,000 Hz with pressure fluctuations of 0.00002 Pa to 20 Pa. This range is referred to as the human hearing range. The following circuit can be used to make ultrasound audible to humans. The following circuit can be used to make ultrasound audible to humans. The circuit was developed by Burkhard Kainka. I have only modified it a little bit. So I use only one supply voltage and added a MOSFET switch so that you can enable and disable the circuit. It is basically a bat detector with an AM/FM radio chip (CD2003) in its core.

The PCB is completely designed with SMD components.

The speaker will later sit directly on the ear.

Of course, you can also use it to make the emitted ultrasonic waves of the HC-SR04 ultrasonic sensor audible. They are heard as a loud, knocking noise.

Microfluid pad

M. Bindhammer • 05/14/2023 at 08:29 • 0 comments

The microfluid pad is used to distribute neurotransmitters, stimulants, medicine, etc. dissolved in a carrier substance (penetration enhancer) on the skin. While in the first prototype, I cast an ABS filament structure in silicone and then dissolved it with acetone to make a microfluid pad, I now want to try another option. For this, three 1mm thick clear acrylic glass sheets are cut out with the laser and glued together in sandwich construction. To do this, I have drawn the three sheets in Inkscape.

Gas sensor

M. Bindhammer • 05/12/2023 at 11:36 • 0 comments

I plan to use the MiCS5524 gas sensor, mainly because it is sensitive to carbon monoxide. Carbon monoxide is a highly toxic, colorless, odorless, and tasteless gas. The gas sensor can also detect other gases, but except for hydrogen, our sense of smell can detect and assign them with the exception of methane, propane, and iso-butane, which smell very similar. Here is an excerpt from the data sheet showing the resistance Rs as a function of the concentration of the various gases:

In the laboratory, a steady stream of carbon monoxide can be produced by dropping formic acid into warm, concentrated sulfuric or phosphoric acid:

That will help us to calibrate the sensor. In fact, we need a second point to calculate the straight-line equation. The sensor must be aged for 24 hours before any characterization or calibration. That is, it must run in clear air for 24 hours.

The two-point form of the linear equation is given by:

y is thereby the analogRead() value and x is the concentration. To calculate the concentration, we need to solve the linear equation for x:

The experimental setup for calibration was as follows. I used 96% sulfuric acid and 70% formic acid. As soon as the formic acid comes into contact with the sulfuric acid, carbon monoxide is produced:

The highest analogRead() value I obtained was 1005 in the carbon monoxide stream. In clean air, the analogRead() value is about 25. If we assume that an analogRead() value of 25 corresponds to 1ppm and an analogRead() value of 1005 corresponds to 1000ppm, we can plug the numbers into the straight line equation and get:

Of course, the whole thing is not particularly accurate, but I'll settle for it for now.