Comfort and learnability assessment of a new soft robotic manipulator for minimally invasive surgery

Laparoscopic surgeons perform precise and time consuming procedures while holding awkward poses in their upper body and arms. There is an ongoing effort to produce robotic tools for laparoscopic surgery that will simplify these tasks and reduce risk of errors to help both the surgeon and the patient. STIFF-FLOP is an ongoing EU FP7 project focusing on this by creating a stiffness controllable soft robotic manipulator. This paper reports on a study to test the soft manipulator's learnability and the effort associated with its use. The tests involved a limited prototype of the manipulator with a custom built test rig and EMG acquisition system. Task times and video recordings along with EMG waveforms from the forearm muscles of participants (n=25) were measured for objective assessment. A questionnaire was also provided to the participants for subjective assessment. The data shows that in average EMG levels were 25.9% less in RMS when using the STIFF-FLOP arm than when conventional laparoscopic tools were used. In terms of learnability, from the first to the second attempt on the STIFF-FLOP manipulator, elapsed time was reduced by an average of 32.1%. Further details and analysis of the EMG signals as well as time and questionnaire results is presented in the paper.

A dual-centre, cohort comparison of open, laparoscopic and robotic-assisted radical cystectomy

INTRODUCTION

The role of minimally invasive radical cystectomy as opposed to open surgery for bladder cancer is not yet established. We present comparative outcomes of open, laparoscopic and robotic-assisted radical cystectomy

MATERIAL AND METHODS

Prospective cohort comparison of 158 patients from 2003-2008 undergoing open radical cystectomy (ORC) (n = 52), laparoscopic radical cystectomy (LRC) (n =58) or robotic-assisted radical cystectomy (RARC) (n = 48) performed by a team of three surgeons at two hospitals. Peri-operative data, complication rates, length of hospital stay, oncological outcome (including lymph node status) and survival were recorded. Statistical analyses were adjusted to account for potential confounding factors such as ASA grade, gender, age, diversion type and final histology.

RESULTS

RARC took longer than LRC and ORC. Patients were about 30 times more likely to have a transfusion if they had ORC than if they had RARC (p < 0.0001) and about eight times more likely to have a transfusion if they had LRC compared with RARC (p < 0.006). Patients were four times more likely to have a transfusion if they had ORC as compared with LRC (p < 0.007). Patients were four times more likely to have complications if they had ORC than RARC (p = 0.006) and about three times more likely to have complications with LRC than with RARC (p = 0.02). Hospital stay was mean 19 days after ORC, 16 days after LRC and 10 days after RARC.

CONCLUSIONS

Despite study limitations, RARC had the lowest transfusion and complication rates and the shortest length of stay, although taking the longest to perform.

An indentation depth-force sensing wheeled probe for abnormality identification during minimally invasive surgery

This paper presents a novel wheeled probe for the purpose of aiding a surgeon in soft tissue abnormality identification during minimally invasive surgery (MIS), compensating the loss of haptic feedback commonly associated with MIS. Initially, a prototype for validating the concept was developed. The wheeled probe consists of an indentation depth sensor employing an optic fibre sensing scheme and a force/torque sensor. The two sensors work in unison, allowing the wheeled probe to measure the tool-tissue interaction force and the rolling indentation depth concurrently. The indentation depth sensor was developed and initially tested on a homogenous silicone phantom representing a good model for a soft tissue organ; the results show that the sensor can accurately measure the indentation depths occurring while performing rolling indentation, and has good repeatability. To validate the ability of the wheeled probe to identify abnormalities located in the tissue, the device was tested on a silicone phantom containing embedded hard nodules. The experimental data demonstrate that recording the tissue reaction force as well as rolling indentation depth signals during rolling indentation, the wheeled probe can rapidly identify the distribution of tissue stiffness and cause the embedded hard nodules to be accurately located.

Robotic assisted radical cystectomy: short to medium-term oncologic and functional outcomes

PURPOSE

To report short- and medium-term oncological and functional outcomes of the first robotic-assisted laparoscopic radical cystectomy (RARC) series from the UK.

MATERIALS AND METHODS

Thirty patients underwent RARC between 2004 and 2007 at our unit. We report oncological and functional outcomes of this procedure in 20 patients (17 ileal conduit and three Studer Pouches), who have completed at least 6 months of follow up.

RESULTS

There were 17 men and three women, median age 66 years (range 38-77 years). Median operating time was 330 min (range 295-510 min), and median blood loss 150 ml (range 100-1150 ml). There were two major complications (10%); a port site bleed and a rectal injury. The median follow up of this cohort is 23 months (range 7-44 months). One patient died of distant metastases at 8 months, and another developed a right ureteric tumour at 7 months. None of the patients had local pelvic or port site recurrence. The overall and disease-free survival are 95% and 90% respectively. Functional complications included a neovesico-urethral stricture at 3 months, a left upper ureteric stricture at 6 months and an incisional hernia at 12 months.

CONCLUSION

Robotic-assisted laparoscopic radical cystectomy is an emerging minimally invasive procedure which at short- to medium-term follow up, in our experience, is oncologically and functionally equivalent to open radical cystectomy.

Robotic renal surgery

Robotic surgery is being increasingly used for prostatectomy. Its use in renal surgery has been limited by a perception that it does not offer any extra benefit. This article explores the use of robot assistance in renal surgery. Extensive literature search undertaken using Medline and PubMed. The following keywords were used during the search: robot, robotic, kidney, renal, nephrectomy, partial nephrectomy, pyeloplasty. Relevant articles were extracted and data from these articles presented in the review. Comments on relevant aspects of either technique or results are provided. Apart from initial feasibility studies, little has been published on robot assisted laparoscopic nephrectomy (RALN) for diseased kidneys. Most of the cases of RALN has been carried out in live donors for renal transplantation in a few enthusiastic centres. Experience with robot assisted laparoscopic pyeloplasty (RALP) is more mature. Robot assisted laparoscopic partial nephrectomy (RALPN) is continuing to evolve. Robotic NOTES is currently experimental. Robot assistance seems to have a role in reconstructive renal procedures such as pyeloplasty and partial nephrectomy, due mainly to the precise suturing ability.

Complications in robotic urological surgery

Robotic technology is having a considerable impact on urological practice at the moment. With the increasing penetration of the da Vinci surgical system into hospitals around the world, surgeons are availing of the opportunities to use this technology to perform complex laparoscopic procedures. Nowhere is this more evident than in urology, where robotic-assisted laparoscopic radical prostatectomy is the most frequently performed robotic procedure of any kind. With the proliferation of this technology there are a number of questions raised. Apart from issues regarding efficacy and economics, complication rates specific to the technology as well as the procedure need to be addressed. This article reviews the current status of complications in robotic urological surgery with respect to both machine-related issues, and procedure-related issues.