Int J CARS (2017) 12:1333–1343
Grasper having tactile sensing function using acoustic reﬂection
for laparoscopic surgery
Hiep Hoang Ly
· Yoshihiro Tanaka
· Tomohiro Fukuda
· Akihito Sano
Received: 11 January 2017 / Accepted: 19 April 2017 / Published online: 28 April 2017
© CARS 2017
Purpose: In current minimally invasive surgery techniques,
the tactile information available to the surgeon is limited.
Improving tactile sensation could enhance the operability
of surgical instruments. Considering surgical applications,
requirements such as having electrical safety, a simple struc-
ture, and sterilization capability should be considered. The
current study sought to develop a grasper that can measure
grasping force at the tip, based on a previously proposed tac-
tile sensing method using acoustic reﬂection. This method
can satisfy the requirements for surgical applications because
it has no electrical element within the part that is inserted into
the patient’s body.
Methods: We integrated our acoustic tactile sensing method
into a conventional grasping forceps instrument. We designed
the instrument so that acoustic cavities within a grasping
arm and a fork sleeve were connected by a small cavity in
a pivoting joint. In this design, when the angle between the
two grasping arms changes during grasping, the total length
and local curvature of the acoustic cavity remain unchanged.
Thus, the grasping force can be measured regardless of the
orientation of the grasping arm.
Results: We developed a prototype sensorized grasper
based on our proposed design. Fundamental tests revealed
that sensor output increased with increasing contact force
applied to the grasping arm, and the angle of the grasping
arm did not signiﬁcantly affect the sensor output. Moreover,
the results of a grasping test, in which objects with different
softness characteristics were held by the grasper, revealed
Department of Electrical and Mechanical Engineering,
Graduate School of Engineering, Nagoya Institute of
Technology, Gokiso-cho, Showa-ku, Nagoya 466-8555, Japan
that the grasping force could be appropriately adjusted to
handle different objects on the basis of sensor output.
Conclusions: Experimental results demonstrated that the
prototype grasper can measure grasping force, enabling safe
and stable grasping.
Keywords Tactile sensor · Grasper · Minimally invasive
surgery · Acoustic reﬂection
In recent years, minimally invasive surgery (MIS), such as
laparoscopic surgery, has become an increasingly standard
surgical procedure in addition to traditional open surgery.
MIS provides numerous advantages to patients, including
less pain, faster recovery time, and better cosmetic healing,
compared with open surgery. However, MIS has several lim-
itations. In particular, the tactile information available to the
surgeon is minimal, causing difﬁculty in the manipulation
of surgical instruments. Semere et al.  and Wagner et al.
 reported that the absence of tactile information such as
force feedback leads surgeons to apply greater force to the tis-
sue. Moreover, surgery with force feedback can signiﬁcantly
reduce the surgeon’s visual fatigue . Thus, the provision
of tactile information to the surgeon might enable safer and
more accurate surgery.
A number of force/tactile sensing systems for MIS have
been developed . Regarding the piezoresistive principle,
King et al.  developed a force sensor using a piezoresistive
array to the forceps tip. On the same principle, Kuwana et
al.  developed a triaxial micro-electro-mechanical systems
tactile sensor using piezoresistive layers and then attached it
to the tip of a grasper for the measurement of grasping force.
Similarly, a triaxial force sensor using p-type piozoresistors