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Shlay is a redesigned laparoscopic monopolar hook used for cauterization. This hand controlled medical device was designed from the ground-up through an extensive research and co-design process with surgeons. Shaly takes into account the need for more ergonomically designed devices that take into consideration the surgeon and patient.


Surabhi Khanna


Design Research

Anthropometric Studies





Undergraduate Thesis

Bio-Tech Incubation

Medical Device Innovation


MEDIC, IIT-Bombay '18


The Monopolar hook is an essential device used in laparoscopic surgery but has been known to cause harm and discomfort to both surgeon and patient. The existing system had issues with

  • Precision and control over device in a small space 

  • ​The need of a contact plate on the patient end (patients with pacemakers can use this as a method of surgery) ​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

  • ​Unwanted cauterization due to  surgeon movement​​​​​​​​​​​​​​​​

  • ​Post-surgery trauma for the patient​​​​​​​​​​​​​


The ideation process began with visits to hospitals and talking to surgeons using the hook. A SWOT analysis was conducted to better understand the current landscape. Through numerous interviews and feedback sessions a concept was developed with three surgeons. The main aim of this stage was to make the procedure more comfortable for both surgeon and patient, whilst increasing the efficiency of the process and reducing complications.


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Shlay for the surgeon:

  • Provides a medical tool that requires lesser instances of failure

  • Removes the need to use a foot-pedal to generate heat via electricity​​​​​​​​

  • ​Increases efficiency by taking away the need to remove the device during off-gassing​​​​​​​​​​​​​​​​​​​​​​​​ and reducing number of devices inside the laparoscopic cavity

  • ​Introduces a device made for ambidextrous use in a space dominated by tools made for right-handed use usage​​​​

Shlay for the patient:​​​​​​​​​​​​​​​​​​​​​​

  • Removes the need for a contact plate, hence eliminating contact burns

  • ​Provides a way forward for patients with pacemakers to benefit from this type of device​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​


View thesis paper


Through various iterations in foam and 3D prints, a simple form was chosen to support an ambidextrous grip. This also included the spring loaded mechanism that would actuate and mimic the linear play of the device, along with balanced weights to give the surgeons a better feel of the potential device.


The design for the grip was driven by hand movements used in calligraphic writing and other high precision dexterous movements.

  • Driven by an ergonomic study, the dynamic quadrupod grip was chosen as it allows for the forefinger to rest on the device and be used for other features

  • ​To combat and remove the need of a contact plate on the patient end, a linear movement shaft was designed to be engaged by the forefinger which heats the curved tip in order to perform cauterization​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​​

  • ​The shaft also has a passageway that allows for smoke to travel out from inside the laparoscopic area (due to differential pressure)​​​​​​​​​​​​ and increase visibility in the region

An analysis of the form's mass, volume and surface are were done to estimate the weight of the device, which was used in future tests with surgeons.​​​​​​​​​​​​​​​​​​​​​​