Assisting control of forces in laparoscopy using tactile and visual - - PowerPoint PPT Presentation

Assisting control of forces in laparoscopy using tactile and visual sensory susbtitution

Thomas HOWARD Jérôme SZEWCZYK

Sorbonne Universités, UPMC Univ. Paris 06, ISIR, CNRS, UMR 7222, INSERM, U1150, Agathe-ISIR, F-75005, Paris, France e-mail: howard@isir.upmc.fr

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Laparoscopic surgery

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Laparoscopic surgery

• Reduced trauma
• Reduced incidence of

complications

• Reduced hospitalization

time

• Reduced convalescence

time

• Better cosmesis
• Reduced cost
• Improved diagnosis

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

[02] H. Xin, J. S. Zelek, H. Carnahan, “Laparoscopic surgery, perceptual limitations and force: A review” [01] O.S. Bholat et al. "Tactile feedback is present during minimally invasive surgery," J Am Coll Surg., vol. 189, pp. 349-355, 1999.

Limitations in perception and action

[01][02]

Laparoscopic surgery : a complex task

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

[02] H. Xin, J. S. Zelek, H. Carnahan, “Laparoscopic surgery, perceptual limitations and force: A review” [01] O.S. Bholat et al. "Tactile feedback is present during minimally invasive surgery," J Am Coll Surg., vol. 189, pp. 349-355, 1999.

Limitations in perception and action

[01][02]

Visual Haptic Dexterity

Laparoscopic surgery : a complex task

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

[02] H. Xin, J. S. Zelek, H. Carnahan, “Laparoscopic surgery, perceptual limitations and force: A review” [01] O.S. Bholat et al. "Tactile feedback is present during minimally invasive surgery," J Am Coll Surg., vol. 189, pp. 349-355, 1999.

Limitations in perception and action

[01][02]

Visual Haptic Dexterity

Hand-eye coordination Partial loss of depth cues Limited FoV Partial loss

• f tactile

perception Distorsions

• f tactile and

kinaesthetic perception Loss of 2 DoF at trocar, inversion of movements, varying lever effect

Laparoscopic surgery : a complex task

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• In laparoscopy, surgeons almost exclusively rely on vision and use the

sense of touch only very little

• Some safety-critical information (interaction forces, position of

instruments within patient) are not available to the surgeon or are available in low quality

• Feed back relevant information to the surgeon in order to assist his/her

gesture,

• Provide said information through the haptic sensory modality as it has a

limited « natural » use in laparoscopy

General problem Observation : Idea :

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

When tightening an intra-corporeal knot in laparoscopy,

• Does feeding back information on the amplitude of the resulting

distal interaction forces allow the surgeon to better control of those forces?

• What are the advantages and drawbacks of various modes of

presentation of this force information?

Controlling distal interaction forces

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

When tightening an intra-corporeal knot in laparoscopy,

• Does feeding back information on the amplitude of the resulting

distal interaction forces allow the surgeon to better control of those forces?

• What are the advantages and drawbacks of various modes of

presentation of this force information?

Controlling distal interaction forces

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Safe zone

Insufficient force Knot may come undone Excess force Thread may break / Tissue may tear Thread tension force [N]

When tightening an intra-corporeal knot in laparoscopy,

• Does feeding back information on the amplitude of the resulting

distal interaction forces allow the surgeon to better control those forces?

• What are the advantages and drawbacks of various modes of

presentation of this force information?

Controlling distal interaction forces

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Safe zone

Insufficient force Knot may come undone Excess force Thread may break / Tissue may tear Thread tension force [N]

When tightening an intra-corporeal knot in laparoscopy,

• Does feeding back information on the amplitude of the resulting

distal interaction forces allow the surgeon to better control those forces?

• What are the advantages and drawbacks of various modes of

presentation of this force information?

Controlling distal interaction forces

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Safe zone

Insufficient force Knot may come undone Excess force Thread may break / Tissue may tear Thread tension force [N]

Setup : Task to be performed :

• Define a target force between 1 and 3N

(for practical reasons) Feedback corresponding to the studied condition is provided

• 1 Force reach task:

Having changed the instrument orientation, aim for the target as precisely as possible

• 1 Force hold task (duration = 20s)
• 3 Force repeat tasks:

Controlling distal interaction forces - protocol

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Setup : Task to be performed :

• Define a target force between 1 and 3N

(for practical reasons) Feedback corresponding to the studied condition is provided

• 1 Force reach task:

Having changed the instrument orientation, aim for the target as precisely as possible

• 1 Force hold task (duration = 20s)
• 3 Force repeat tasks:

Controlling distal interaction forces - protocol

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Setup : Task to be performed :

• Define a target force between 1 and 3N

(for practical reasons) Feedback corresponding to the studied condition is provided

• 1 Force reach task:

Having changed the instrument orientation, aim for the target as precisely as possible

• 1 Force hold task (duration = 20s)
• 3 Force repeat tasks:

Controlling distal interaction forces - protocol

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

EXPERIMENT

Performance comparison between : Conventional laparoscopy (L), with visual force feedback (V), continuous vibrotactile force feedback (T), three variants of pulsed vibrotactiles force feedback (Uf, Up, Uq), and visuel+tactile combinations (TV, UV)

POPULATION

16 subjects (all novices in laparoscopy)

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Controlling distal interaction forces - protocol

RANDOMIZATION

Full Randomization of conditions : L – V – T – Uf –Up – Uq – {One variant of visual+tactile combination}

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

Experimental conditions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Experimental conditions

• [L] Reference – Laparoscopy :

Closed laparo-trainer, simple endoscopic image, no feedback of force magnitude

• [V] Visual feedback

Feedback of force magnitude through on-screen bar-graph

• [T] Continuous proportional vibrotactile feedback

Provided by an ERM motor strapped to the subject’s hand

• [U Pulsed vibrotactile feedback

– F]: fixed pulse length, interval between pulses varying proportionally to the exerted force – P]: pulse length and interval jointly vary proportionally to the exerted force – Q]: fixed pulse interval, pulse length varying proportionally to the exerted force

• TV, UfV, UpV, UqV : Combinaisons de retours visuels+vibrotactiles

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Some examples of obtained force curves

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Some examples of obtained force curves

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

(a) Mean distance to target force after aiming, divided by subject performance in condition (L) [dimensionless] Medians : light blue horizontal lines Means : red horizontal lines (b) Mean distance to target after aiming [mN]

Results : Accuracy of aiming for a target force

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

(a) Mean distance to target force after aiming, divided by subject performance in condition (L) [dimensionless] Medians : light blue horizontal lines Means : red horizontal lines (b) Mean distance to target after aiming [mN]

Results : Accuracy of aiming for a target force

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

(a) Mean distance to target force after aiming, divided by subject performance in condition (L) [dimensionless] Medians : light blue horizontal lines Means : red horizontal lines (b) Mean distance to target after aiming [mN]

Results : Accuracy of aiming for a target force

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

(a) Mean distance to target force after aiming, divided by subject performance in condition (L) [dimensionless] Medians : light blue horizontal lines Means : red horizontal lines (b) Mean distance to target after aiming [mN]

Results : Accuracy of aiming for a target force

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Speed of aiming for a target force (Target force / TCT) of subjects divided by final aiming error, normalized by subject’s performance in condition L [dimensionless]

Results : Speed of aiming for a target force at constant accuracy

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Speed of aiming for a target force (Target force / TCT) of subjects divided by final aiming error, normalized by subject’s performance in condition L [dimensionless]

Results : Speed of aiming for a target force at constant accuracy

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Speed of aiming for a target force (Target force / TCT) of subjects divided by final aiming error, normalized by subject’s performance in condition L [dimensionless]

Results : Speed of aiming for a target force at constant accuracy

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Speed of aiming for a target force (Target force / TCT) of subjects divided by final aiming error, normalized by subject’s performance in condition L [dimensionless]

Results : Speed of aiming for a target force at constant accuracy

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Results : Drift and cumulative deviation

Mean drift angles during the force hold task [N/s], divided according to drift direction The number of observations for each case is indicated above or below the respective box-plots

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Results : Drift and cumulative deviation

Mean drift angles during the force hold task [N/s], divided according to drift direction The number of observations for each case is indicated above or below the respective box-plots

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Results : Drift and cumulative deviation

Mean drift angles during the force hold task [N/s], divided according to drift direction The number of observations for each case is indicated above or below the respective box-plots

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Results : Drift and cumulative deviation

Mean drift angles during the force hold task [N/s], divided according to drift direction The number of observations for each case is indicated above or below the respective box-plots

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Results : Drift and cumulative deviation

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Cumulative deviations during the force hold task [N.s]

Results : Drift and cumulative deviation

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Cumulative deviations during the force hold task [N.s]

Results : Drift and cumulative deviation

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Cumulative deviations during the force hold task [N.s]

Results : Drift and cumulative deviation

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Cumulative deviations during the force hold task [N.s]

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

• Feeding back information (tactile, visual or combined) improves :

– Accuracy of aiming for a target force (up to 85.8% in error reduction) – Repeatability (up to 84% reduction in spread of errors in final force error during aiming) – Speed of aiming for a target force at equal accuracy (up to 18-fold speed increase)

• Concerning holding a force level over time:

– Reduction of the mean force error during holding – Reduction of drift and cumulative deviation

• Best results were obtained by using visual feedback
• However, pulsed vibrotactile feedback (Uf and Up) provide promising

performances

• Combination of visual and vibrotactile feedback does not seem to yield

any systematic improvement over either form of feedback by itself

General conclusions

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

– Presence of additional reference information (distance to max. and min. of the range of forces) – Speed of information delivery – Experimental bias => Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

– Feedback of absolute force level (as presented here) – Feedback of absolute force level with explicit target as a reference – Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

• Presence of additional reference information (distance to max.

and min. of the range of forces) – Speed of information delivery – Experimental bias => Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

– Feedback of absolute force level (as presented here) – Feedback of absolute force level with explicit target as a reference – Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

• Presence of additional reference information (distance to max.

and min. of the range of forces)

• Speed of information delivery

– Experimental bias => Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

– Feedback of absolute force level (as presented here) – Feedback of absolute force level with explicit target as a reference – Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

• Presence of additional reference information (distance to max.

and min. of the range of forces)

• Speed of information delivery
• Experimental bias

=> Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

– Feedback of absolute force level (as presented here) – Feedback of absolute force level with explicit target as a reference – Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

• Presence of additional reference information (distance to max.

and min. of the range of forces)

• Speed of information delivery
• Experimental bias

Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

– Feedback of absolute force level (as presented here) – Feedback of absolute force level with explicit target as a reference – Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

The clear superiority of visual feedback could be due to:

• Presence of additional reference information (distance to max.

and min. of the range of forces)

• Speed of information delivery
• Experimental bias

Currenlty, an similar experiment including a concurrent visual task (better ecological validity) is being set up

Upcoming work : Comparison of performances between:

• Feedback of absolute force level (as presented here)
• Feedback of absolute force level with explicit target as a

reference

• Feedback of force error with respect to a pre-defined target

Current and future work

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

Thank you for your attention !

"Assisting control of forces in laparoscopy using tactile and visual sensory substitution“ T. Howard, J. Szewczyk; MESROB 2015, 8 - 10 juillet 2015, Nantes

This work was supported by French state funds managed by the ANR within the Investissements d’Avenir programme (Labex CAMI) under reference : ANR-11-LABX-0004

Contact e-mail: howard@isir.upmc.fr