Pulsate is an open system[1] that generates screen from human pulse cycles. It captures sequential heartbeats and represents them into changing patterns. Thus, Its display can be seen as a visible form of heart sounds that are varied by the changing tones.

There was an assumption derived from my previous work[2], there might be mute tones in heartbeats. The tones are not counted in commercial and some medical heart readers. The further research on cardiopulmonary function showed that the tones cannot be beard with human ears, but may be useful for medical diagnostics[3]. Also, with auscultatory[4] method, I heard lub (peak) and dub (faint) sounds in every pulsation. It means the regular heart reader machines subjectively count only the peak tones. I therefore decided to create Pulsate as a DIY pulse reader in serving 2 purposes. One was to amplify the sceptical tones, and another was to return the regular heart rate (bpm) close to the result from regular devices.

Pulsate consists of body system: heart, hand and eyes, technological system: a microphone, a computer and keyboard, Processing software with Sonia plugged-in, and a display: a projector and a 2D plane. The user’s heart is employed as data supplier feeding pulse signals to the machines. Processing is the co-processor (with heart) ruling all the changes that appear on the display. The microphone is a transducer bridging the body, machines and the display giving an organic loop[5] character to the whole system.

Figure 1: System map of Pulsate

My research on heart anatomy and explorations on different types of pulse readers i.e. Pulse-rate Monitor Kit[6] showed that a tie-clip microphone was the most appropriate device to serve the brief. It captured all tones the heart created when hooked up with Sonia and the method LiveInput.start() was executed. It also showed the order of peak and faint volumes in cycles with function getMeterLevel().

Figure 2:  Method map base on methods used in Processing code

Yet, the value of bpm was still problematic. It led to observations on the sequential volumes of heart tones seen in Processing console[7], and further research on 4 sounds in single blood flow[8], which are created by Bicuspid, Tricuspid, Aortic and Pulmonic valves in the heart[9]. These gave an idea to divide the total number of beatCounter++ by 4 and limit the white noise with minValue; the system has succeeded in returning the regular bpm rates.

Figure 3: Blood flow between heart chambers included 4 valves. Taken from
<http://www.smm.org/heart/heart/pumping.htm> [Accessed 8 March 2008]

There have been several projects generating displays from heartbeats[10] [11] [12] [13]. One of the well-known artworks is Simon Tegala’s Anabiosis (1998), which publicly broadcasted the artist’s heartbeats over 2 weeks on an electronic board in London. It displayed the text ‘Simon Tegala’s heart rate is…125’[14]. Unlike Anabiosis that made a one-to-all dialogue from the artist to the audiences, Pulsate is central to its single user and represents an intimate relationship between the user and the work, and between the user, other audiences and the space.

The function void keyPressed() opens the two-way dialogue from the second screen allowing the user to type their id i.e. name and age. The texts are translated into numbers and used as primitive values to control size, colour and stroke of geometric shapes forming pattern based on Gestalt principle[15]. With ability to turn an empty surface to live, the display of Pulsate can be projected on any surface i.e. walls in users’ house, dancing floors, a display in a yoga room, spa ceilings or in any environment that engages user’s body and visual cognition[16].

However, the system and display of this work still require refinements. The condition in forming patterns and colours involves more research on Processing code and generative art theories[17] [18]. Also, the development on designing prototype and additional components i.e. a potentiometer and alternative pulse readers are needed. Nake and Grabowski ask, ‘How important an aesthetic perspective is for understanding and designing interaction?’  (Nake and Grabowski, 2006, p.53), this will be the starting point for development[19].

Last Update 20 March 2008