Haptic Feedback in the Da Vinci Surgical System

The Da Vinci Surgical System is a robot built by Intuitive Surgical. After being approved for use by the FDA in 2000, it has been adopted by surgeons performing a wide range of minimally invasive procedures, including prostatectomies, cardiac valve repair, and gynecologic procedures. As of June 30, 2014, approximately 3,100 Da Vinci robots were installed worldwide, with each unit costing roughly $2 million. The primary innovation of the Da Vinci system is the surgeon’s console: an immersive visualization system that takes an ordinary laparoscopic image and projects it to a binocular display, enhancing the dexterity with which a surgeon can perform several procedures. For the patient, the Da Vinci system typically provides a reduced amount of pain and blood loss, frequently resulting in a shorter hospital stay and faster recovery period. Continue reading “Haptic Feedback in the Da Vinci Surgical System”

Getting Started with Haptic Feedback (Arduino Guide)

The DRV2605 breakout board from Adafruit.
The DRV2605 breakout board from Adafruit.

Adafruit provides a breakout board for the DRV2605 haptic driver from Texas Instruments. Although the example tutorial included with the product describes a quick way to set up the driver with an eccentric rotating mass (ERM) motor, we prefer using a linear resonant actuator (LRA) for increased precision and enhanced haptic feedback. You can use the breakout board with an Arduino Uno to quickly make a prototype of a system that delivers precise vibrotactile cues.

Materials & Supplies

Hardware

Software

Additional Resources

Creating Haptic Feedback

Step 1: Soldering

The DRV2605 breakout board attached to a LRA.
The DRV2605 breakout board attached to a LRA.

Solder the header strip onto the breakout board, and solder the LRA onto the breakout board. After this step, your DRV2605 breakout board should look like this:

Step 2: Wiring and Hookup

  • Connect VIN on the DRV2605 to the 5V supply of the Arduino
  • Connect GND on the DRV2605 to GND on the Arduino
  • Connect the SCL pin to the I2C clock SCL pin on your Arduino, which is labelled A5
  • Connect the SDA pin to the I2C data SDA pin on your Arduino, which is labelled A4
  • Connect the IN pin to an I/O pin, such as A3

Step 3: Testing and Creating Effects

Adafruit provides a very useful Arduino library for the DRV2605 that you can use to get started. In particular, we recommend looking through the example code to get an idea of the effects you can produce. In page 57 and 58 of the DRV2605 datasheet, you can find a table of all the effects you can produce “out of the box.”

Step 4: Creating Your Own Waveforms

Since you can also set the intensity of the LRA in realtime, you can design your own waveforms and effects by changing the value over time. Adafruit also provides an example for setting the value in realtime on Github. You can combine this example code with a waveform design tool like Macaron to customize the feedback provided by your new Arduino-powered haptic device!

How We Filmed our Crowdfunding Video for Under $2,000

We’re a small startup, and we don’t have a large marketing budget. When we started working on our crowdfunding campaign, we took a look at a few of the most successful crowdfunded products:

We asked ourselves: what do they all have in common? They all had a video with excellent production value – a video that could cost anywhere from $25,000 to $100,000 or more depending on whether or not the actors were paid.

As a startup that’s bootstrapped and hasn’t raised a large round of investment, we needed to get creative. We used $2,000 of our savings to film a video that could have easily cost 10x as much. We recruited a bunch of our talented friends who are musicians, dancers, researchers, and body builders. Then, we filmed footage and edited until we reached our final iteration:

Continue reading “How We Filmed our Crowdfunding Video for Under $2,000”

3D Printing: Ready for mass market?

Shrek 3D Print

While revising the 3D design for Moment, I started off using a Makerbot Replicator at TechShop. These machines were the first to usher in an era of accessible consumer 3D printing. The bundled software is easy to use, and the printers generally work well. That said, with a $2,000 price tag, they aren’t truly accessible to the average consumer, and a TechShop membership can also be expensive if you don’t use it regularly. With affordable rapid-prototyping in mind, I began asking “Can you get started 3D printing for less?”.

Now, with the Monoprice MP Select Mini, you can. At an MSRP of $200, I decided to get one and try it out for myself. It doesn’t disappoint. It works with a wide range of filaments (ABS, PLA, XT Copolyester, PET, TPU, TPC, FPE, PVA, HIPS, Jelly, Foam, Felty), including a PLA-based wooden filament from Hatchbox. After 3D printing a few models of Shrek and some geometric Pokemon, I was impressed.

Pokemon 3D Print

The Good

  • absurdly cheap ($200)
  • heated print bed
  • compatible with many different filaments
  • solid exterior built of steel and aluminum (very few plastic parts)
  • full color LCD display on the printer
  • MicroSD card slot
  • works with Cura software from Ultimaker
  • possibly capable of connecting to wifi networks in a future firmware update
  • print bed leveled out of the box
  • active user community
  • 1-year limited warranty
  • extremely accurate Z-axis motor (possibly more than 100 micron resolution)

The Bad

  • limited print space (120x120x120 millimeters)
  • very minimal instructions – debugging can be hard
  • cheap built plate material (scratches easily)
  • imprecise temperature regulation
  • no enclosure or hood around prints
  • non-standard parts that require warranty replacement or buying a new printer

Conclusion

If you’re looking to get started with 3D printing, or want to try out different filament types inexpensively, buy this printer. Its price sets it apart from the competition. Any comparable printer is easily 3x the price, but the additional cost may also come with improved reliability—only time will tell whether the MP Select Mini is a durable product.

Macaron and the Future of Haptic Editors

Screenshot of the Macaron interface.
A screenshot of the Macaron haptic effects editor.

Earlier this week, we had the pleasure of talking to Oliver Schneider, a graduate student and researcher at the University of British Columbia. Working at the Sensory Perception & Interaction Research Group, Oliver spends most of his days developing new software and hardware interfaces that engage our sense of touch. He described various techniques he used to create development tools and interfaces for creating rich tactile effects, including Haptic Jazz – a system for taking improvisational input on a tablet and translating it in real-time into a vibrotactile sensation. Continue reading “Macaron and the Future of Haptic Editors”

The Future of 4D Home Cinema: A Haptic Effects Track

Diagram of 4D Movie Theater
Diagram of a 4D movie theater from Wikipedia.

With the rise of Netflix and Youtube as dominant platforms for video consumption, fewer people are visiting theaters to watch movies. An increasing amount of multimedia content will be designed for the home theater as these streaming services grow their libraries. Netflix users consume content on whichever screen is available: a laptop, tablet, or smartphone. As the user experience for content consumption shifts towards mobile applications and at-home viewing, the interactive elements of 3D and 4D film previously reserved for movie theaters will transition to technologies easily adopted by households.

Good video is engaging – it tells a compelling story with excellent production value. Since there is increasing competition for viewership between different streaming platforms, devices, and content production studios, there is an increasing demand for differentiated content – content that provides a unique experience to its viewers. Continue reading “The Future of 4D Home Cinema: A Haptic Effects Track”

Temperature Feedback with the Thermoelectric (Peltier) Effect

Photograph of a thermoelectric cooler (Peltier diode)
A Peltier diode available from Sparkfun Electronics.

Vibrotactile pulses (e.g. the buzzing of a cell phone or game controller) can provide users with real-time feedback in a computer interface, but it’s not the only way to transmit information through the sense of touch. Modulating the temperature of the surface of a device can also provide additional information to users.

When a current flows through a junction between two different conductors, heat can be generated or removed from the junction. This phenomenon is called the Peltier effect, named after physicist Jean Charles Athanase Peltier. Different conductive materials that exhibit a Peltier effect will generate or remove different amounts of heat proportional to the amount of current running through the junction – the Peltier coefficient measures how much heat is carried for every unit of charge flowing through the device. Continue reading “Temperature Feedback with the Thermoelectric (Peltier) Effect”

Impairments to Tactile Perception

Managing diabetes can be extremely difficult, but the risks otherwise can be severe
Managing diabetes can be extremely difficult, but the disease may otherwise cause nerve damage.

Skin sensitivity can be impaired by many different diseases and disorders. Although skin injuries (burns, incisions, etc.) and nerve lesions (from injury or restricted blood circulation) are the most commonly experienced causes of decreased sensitivity, several metabolic, toxic, and immunologic factors can influence haptic perception.
One of the most common complications of diabetes, known as diabetic neuropathy, results in damage to the nerves of the body that cause numbness, tingling, and pain. Diabetes can also slow the healing of cuts and cause rashes that alter the sensitivity of an area of skin. Continue reading “Impairments to Tactile Perception”

How Humans Explore Objects via Touch

A person holding a strawberry in their hand.

People rapidly and accurately identify 3-dimensional objects using only their sense of touch [1]. This process occurs through a sequence of exploratory procedures that underlie the cognitive strategies used to conclusively identify an object entirely through its haptic features. The following four procedures are the most common methods for tactile exploration [2]. Continue reading “How Humans Explore Objects via Touch”