E-finger: a tactile diagnostic device with microscale resolution

An approach is proposed to the in vivo assessment of soft tissue quality using multi-scale mechanical measurements. The approach is applied to prostate gland compliance (as measured by dynamic modulus, E) using a micro-engineered probe for the detailed assessment of prostate cancer (PCa) building on our earlier work applied to benign prostatic hyperplasia (BPH). We have previously shown for the first time that a relationship exists between the mechanical and histological characteristics of the prostate in vitro. We wish to apply our findings to the in vivo setting, with the development of a remote palpation instrument for in vivo measurement of prostatic compliance in malignant disease. Such a device is likely to lead to major advances in the diagnosis, assessment and surveillance of men with PCa and emphasis is therefore placed on minimum levels of invasiveness. It is also expected that the study will result in a novel medical instrument and associated design paradigm of generic value for other applications where a remote or minimally-invasive measure of tissue quality is desired. The work will emphasise the importance of probe size and will investigate the interface between meso- and micro-scale measurements (tissue-level) and micro- to nano-scale measurements (cell-level) and a simple method for producing a range of probe sizes and levels of resolution is outlined.The projected is expected to deliver:- the first in vivo mechanical measurement of dynamic modulus- the first micro-scale in vivo mechanical measurement- the first approach applied to prostate compliance which integrates trans-urethral, trans- rectal and laparoscopic measurements- the first study of mechanically-assessed prostate tissue quality which uses a large number of patients A major feature of the work is the co-operation of clinicians and medical and engineering academics focused onto a problem with potential huge implications for the ageing population. The impact plan aims top exploit the immediate application to urology through two key industrial partners and a strong engagement with the UK and European urological community. A separate group will be established to examine the transfer of the findings to other medical specialisms, including hepato-biliary surgery and gastro-enterology.

The primary beneficiaries of the work are ultimately the patients who suffer from prostate cancer. Development of a successful device would represent a significant advance in PCa diagnosis, assessment and surveillance. This guide to therapeutic decision-making would assist the urologist in avoiding the situation where a man with a clinically insignificant cancer may undergo radical treatment unnecessarily, whilst others may not receive the treatment they require. A longer-term benefit of tissue quality assessment associated with assessing the positive surgical margin during radical prostatectomy is also likely. Here, this technology may lead to improved results from radical prostatectomy, both in terms of oncologic outcome and the effect upon the patient's quality of life. A more general benefit in tissue quality assessment in minimally invasive surgery generally, providing a degree of force feedback to the surgeon, is also possible and the significance of this will become clearer as the project progresses and we engage with specialisms outside the area of urology. Finally, the most exciting potential benefit is in further miniaturisation to improve the resolution of the assessment as this will provide motivation for further research. Manufacturers of cystoscopes and laparoscopic surgical devices will benefit through exploitation of any probes designed specifically to complement their range of products. It may be anticipated that the current indications for local anaesthetic cystoscopy will be increased if it can be shown that such an examination can provide detailed diagnostic information allowing better direction of therapeutic interventions. Similarly force feedback devices that can be delivered along laparoscopic ports providing quantitative tissue quality measures during surgery can help to improve decision-making during such interventions. Similarly, TRUS system manufacturers will benefit through the development of current applications of TRUS-based assessment of the prostate. The device would allow more detailed TRUS prostate assessment both with and without needle biopsy and other methods of assessing tissue quality, such as electrical impedance tomography [48] can also benefit from benchmarking against an absolutely-calibrated technique. Ultimately, the difference between the palpation device and any other elastography system is in the imaging of the strain, here done directly using a displacement measurement with high spatial resolution. The scientific benefits are in improved medical diagnostics, including the development of the notion of structure-property relationships for tissue quality assessment, and an increased understanding of the issues involved in the design and fabrication of microdevices for real-world applications and in dealing with the interfacing and packaging issues. The project team will use two main groups to engage users and beneficiaries; a high-level Advisory Committee and a Steering Group, to be co-ordinated by the Commercialisation Officer, who will keep records of the Steering Group and Advisory Committees and the Focus Group and Brainstorming Events, and also attend relevant conferences and visit companies in pursuit of the interests of the project. The project will create a large number of new cross functional collaborative links between industry / academia in the field of medical device design, micro-mechanics and sensing. Results of the project will be disseminated in the normal way, through conferences and publications in the engineering and medical literature. Our publication strategy will engage with the international communities in the three specialist areas; medical engineering, microengineering and urology, but in a co-ordinated and integrated way to the extent that some publications will involve both of the project partners. There is now a growing world-wide community in mechanical-based medical diagnostics and we expect to continue to cite and be cited by these groups.