Haptics · Medical applications

Haptic feedback in medical applications


This second blog post about haptics as an interaction modality, will be devoted the area of medicine. During recent years haptics has become more and more important in medical applications, when it comes to both training, simulation and image analysis. An important rationale behind using the haptic modality in medical training applications is, of course, that you can get “the real feeling” and practice motor skills without actually having to practice on a patient.

There are several examples of cases in which the addition of haptic feedback to a visual interface has proven to make a positive difference in medical simulators. I will just bring up two examples here to illustrate the potential of haptic feedback.

A group of Chinese researchers developed a simulator for training Chinese acupuncture (reference is, sadly, behind a pay wall). Places where a simulated needle (controlled by the haptic device I described here) could be inserted were highlighted on a virtual patient’s back and when inserting the needle it was also possible to feel the difference between different tissues (the stiffness varied). By using this simulator students could not only learn where needles should be inserted but also how it should feel when the needle was at the correct place.

A haptic simulator, named the Kobra, for extraction of wisdom teeth, was actually developed at KTH, by Ph. D. Jonas Forsslund. This simulator is shown in the image above (source: Forsslund Systems). In this simulator the user can perform an entire wisdom tooth extraction procedure by using a virtual drill, operated by pedals. During the procedure, a semitransparent mirror is used for hand-eye coordination and a pair of 3D glasses gives the depth perception. In the image above you can also see the haptic device (shown as the drill in the virtual environment) and the mannequin placed under the semitransparent mirror. The positions of the mannequin and of the virtual head are synchronized so that the hand can rest on the mannequin while using the virtual drill on one of the wisdom teeth! The Kobra project actually started off as a master’s thesis project in 2008 and has now become a commercial product! You can read a lot more about this simulator on: Forsslund Systems.

Both of the above examples illustrate one of the important functions haptic feedback can play in medical simulators – you can practice motor skills and certain procedures without having to be dependent on involving patients. This is extra important in the dental simulator case, where it is possible to practice procedures which are not that easy to describe in theory. You can practice the same procedure over and over again without wearing out a material or risk hurting a patient. During initial evaluations it was shown that it was indeed possible to simulate the procedure of bone drilling, but effects on performance could not be shown. I think there is a good chance that future evaluations could show a positive effect on learning outcome.

Another area, not brought up yet, where haptic feedback can be an aid within the medical domain is surgical planning. I performed research myself within that area during my Ph. D. studies at KTH, when I evaluated an application for surgical planning, developed by Jonas Forsslund, with doctors at the Karolinska Hospital. I will, however, get back to that particular study in a later blog post, when results from the study have been published. Those who are curious can read about some pre-studies and the haptic application here (only the abstract is shown, but if you have access to IEEE-publications you can follow the provided DOI to find the paper).