A medical tactile sensing instrument for detecting embedded objects, with specific application for breast examination

Tactile Perception Technologies and Their Applications in Minimally Invasive Surgery: A Review

Minimally invasive surgery (MIS) has been the preferred surgery approach owing to its advantages over conventional open surgery. As a major limitation, the lack of tactile perception impairs the ability of surgeons in tissue distinction and maneuvers. Many studies have been reported on industrial robots to perceive various tactile information. However, only force data are widely used to restore part of the surgeon’s sense of touch in MIS. In recent years, inspired by image classification technologies in computer vision, tactile data are represented as images, where a tactile element is treated as an image pixel. Processing raw data or features extracted from tactile images with artificial intelligence (AI) methods, including clustering, support vector machine (SVM), and deep learning, has been proven as effective methods in industrial robotic tactile perception tasks. This holds great promise for utilizing more tactile information in MIS. This review aims to provide potential tactile perception methods for MIS by reviewing literatures on tactile sensing in MIS and literatures on industrial robotic tactile perception technologies, especially AI methods on tactile images.

Latest technology in minimally invasive thoracic surgery

From the introduction of video-assisted thoracoscopic surgery (VATS) in the 1990s, to performing major lung resections using a uniportal VATS approach, technology has paved the way for the development of minimally invasive thoracic surgery. Natural orifice access to achieve a 'no port' approach, is also on the rise, with advancements in bronchoscopic techniques for diagnosis and therapy, as well as development of soft robotics to achieve desired flexibility, dexterity and stability in future platforms, which may involve in vivo deployment to bring the surgeon totally inside the body. Development of haptic feedback in robotic platforms to enhance the surgical experience is also a major goal, with vibrotactile and mechanical feedback generation, to replicate the traditional touch. In addition, the aid of technology in the form of procedural guidance mechanisms, like augmented reality, will further improve the safety and accuracy of future operations.

Real-Time Vision-Based Stiffness Mapping †

This paper presents new findings concerning a hand-held stiffness probe for the medical diagnosis of abnormalities during palpation of soft-tissue. Palpation is recognized by the medical community as an essential and low-cost method to detect and diagnose disease in soft-tissue. However, differences are often subtle and clinicians need to train for many years before they can conduct a reliable diagnosis. The probe presented here fills this gap providing a means to easily obtain stiffness values of soft tissue during a palpation procedure. Our stiffness sensor is equipped with a multi degree of freedom (DoF) Aurora magnetic tracker, allowing us to track and record the 3D position of the probe whilst examining a tissue area, and generate a 3D stiffness map in real-time. The stiffness probe was integrated in a robotic arm and tested in an artificial environment representing a good model of soft tissue organs; the results show that the sensor can accurately measure and map the stiffness of a silicon phantom embedded with areas of varying stiffness.

Feasibility of spatial frequency-domain imaging for monitoring palpable breast lesions

In breast cancer diagnosis and therapy monitoring, there is a need for frequent, noninvasive disease progression evaluation. Breast tumors differ from healthy tissue in mechanical stiffness as well as optical properties, which allows optical methods to detect and monitor breast lesions noninvasively. Spatial frequency-domain imaging (SFDI) is a reflectance-based diffuse optical method that can yield two-dimensional images of absolute optical properties of tissue with an inexpensive and portable system, although depth penetration is limited. Since the absorption coefficient of breast tissue is relatively low and the tissue is quite flexible, there is an opportunity for compression of tissue to bring stiff, palpable breast lesions within the detection range of SFDI. Sixteen breast tissue-mimicking phantoms were fabricated containing stiffer, more highly absorbing tumor-mimicking inclusions of varying absorption contrast and depth. These phantoms were imaged with an SFDI system at five levels of compression. An increase in absorption contrast was observed with compression, and reliable detection of each inclusion was achieved when compression was sufficient to bring the inclusion center within ∼12  mm of the phantom surface. At highest compression level, contrasts achieved with this system were comparable to those measured with single source-detector near-infrared spectroscopy.

A Magnetoresistive Tactile Sensor for Harsh Environment Applications

A magnetoresistive tactile sensor is reported, which is capable of working in high temperatures up to 140 °C. Hair-like bioinspired structures, known as cilia, made out of permanent magnetic nanocomposite material on top of spin-valve giant magnetoresistive (GMR) sensors are used for tactile sensing at high temperatures. The magnetic nanocomposite, consisting of iron nanowires incorporated into the polymer polydimethylsiloxane (PDMS), is very flexible, biocompatible, has high remanence, and is also resilient to antagonistic sensing ambient. When the cilia come in contact with a surface, they deflect in compliance with the surface topology. This yields a change of the GMR sensor signal, enabling the detection of extremely fine features. The spin-valve is covered with a passivation layer, which enables adequate performance in spite of harsh environmental conditions, as demonstrated in this paper for high temperature.

Diagnostic accuracy of tactile imaging in selecting patients with palpable breast abnormalities: a prospective comparative study

Unnecessary referrals of patients with breast lumps represent a significant issue, since only a few patients actually have lumps when examined by a breast specialist. Tactile imaging (TI) is a novel modality in breast diagnostics armamentarium. The aim of this study was to assess TI's diagnostic performance and compare it to clinical breast examination (CBE). This is a prospective, blinded, comparative study of 276 consecutive patients. All patients underwent conventional imaging and tissue sampling if either a radiological or a palpable abnormality was present. Sensitivity, specificity and positive and negative predictive values for CBE and TI were calculated. Radiological findings and final diagnosis based on histology and/or cytology were used as reference standards. Receiver operator characteristic (ROC) curve analysis was also performed for each method. Sensitivity and specificity of TI in detecting radiologically proven abnormalities were 85.5 % and 35 %, respectively. CBE's sensitivity was 80.3 % and specificity 76 %. In detecting a histopathological entity according to histology/cytology, sensitivity was 88.2 % for TI and 81.6 % for CBE. Specificity was 38.5 % and 85.7 % for TI and CBE, respectively. These results suggest a trend towards higher sensitivity of TI compared to CBE but significantly lower specificity. Subgroup analysis revealed superior sensitivity of TI in detecting a histological entity in pre-menopausal women. However, CBE's overall performance was superior compared to TI's according to ROC curve analysis. Although further research is necessary, the use of TI by the primary care physician as a selection tool for referring patients to a breast specialist should be considered especially in pre-menopausal women.

A proof-of-principle robot with potential for the development of a hand-held tactile instrument for minimally-invasive artery cross-clamping

One of the most common diseases of the vascular system is abdominal aortic aneurysm (AAA), for which the most definitive treatment is surgery. Minimally invasive aorta surgery is a novel method of surgery performed through small incisions and offers significant advantages including less pain, shorter hospital stay, faster patient recovery, less possibility of infection, etc. However, lack of sense of touch is the main drawback of this type of aorta surgery that would incapacitate the surgeon to exactly distinguish the aorta from its surrounding tissues which could cause various problems during the aorta cross-clamping process. One of the most important drawbacks is that it makes the aorta cross-clamping process the most time-consuming process of aortic repair surgery. The artificial tactile sensing approach is a novel method that can be used in various fields of medicine and, more specifically, in minimally invasive surgeries, where using the 'tactile sense' is not possible. In this paper, considering the present problems during aortic-repair-laparoscopy and imitating the movement of surgeons' fingers during aorta cross-clamping, a novel tactile-based artery cross-clamping robot is introduced and its function is evaluated experimentally. It is illustrated that this new tactile-based artery cross-clamping robot is well capable of dissecting an artery from its adjacent tissues in a short time with an acceptable accuracy.

The tactile sensation imaging system for embedded lesion characterization

Elasticity is an important indicator of tissue health, with increased stiffness pointing to an increased risk of cancer. We investigated a tissue inclusion characterization method for the application of early breast tumor identification. A tactile sensation imaging system (TSIS) is developed to capture images of the embedded lesions using total internal reflection principle. From tactile images, we developed a novel method to estimate that size, depth, and elasticity of the embedded lesion using 3-D finite-element-model-based forward algorithm, and neural-network-based inversion algorithm are employed. The proposed characterization method was validated by the realistic tissue phantom with inclusions to emulate the tumors. The experimental results showed that, the proposed characterization method estimated the size, depth, and Young's modulus of a tissue inclusion with 6.98%, 7.17%, and 5.07% relative errors, respectively. A pilot clinical study was also performed to characterize the lesion of human breast cancer patients using TSIS.

Application of artificial palpation in vascular surgeries for detection of peripheral arterial stenosis

Palpation is one of the applied methods that surgeons usually use during surgery in order to verify the health condition of a tissue/organ. In fact, most of surgical assessments are based on analysis of the force feedback received from tissue/organ via palpation. Although palpation has a key role in efficient progress of surgery operations, it depends very much on the experience and skill of the surgeons. This limits the application of this technique in some cases to a large extent. In this regard, an artificial tactile sensing approach is an innovative technology that tries to make tactile data more available for surgeons, especially in situations where doing the palpation is not possible or is too difficult. In this paper, having considered the present problems of artery bypass surgery in peripheral arterial occlusive disease (PAOD), applicability of a new tactile sensory system capable of detecting arterial stenosis during surgery was evaluated. Presenting the modelling and numerical solution of the problem, it was demonstrated that the artificial tactile sensing approach is not only capable of detecting the presence of an arterial stenosis in an artery, but also its type. Furthermore, it was shown that the new tactile sensory system (previously designed, fabricated and tested in laboratory) is efficiently capable of detecting the simulated artery in the simulated biological tissue as well as diagnosis of the stenosis occurred inside it.

A triple-jaw actuated and sensorized instrument for grasping large organs during minimally invasive robotic surgery

BACKGROUND

Secure grasping and effective manipulation of delicate large organs during robotic surgery operations needs especially designed instruments that can enclose a large amount of tissue and feed back the pinch forces.

METHODS

A large organ triple-jaw grasper was instrumented using practical force sensory and actuating systems. A force tracking scheme was proposed to facilitate auto-grasping of large organs during robotic teleoperation surgery. An on-site force commanding/reflecting mechanism was also implemented to use the device as an independent hand-held robotic instrument. The efficacy of the robotic grasper was examined in phantom tests.

RESULTS

The instrument grasped large soft objects effectively and safely with accurately measured and controlled pinch forces. Furthermore, it could characterize the overall mechanical behavior of the grasping objects.

CONCLUSIONS

The instrument designed provides a potential solution for the safe and effective grasping and manipulation of large abdominal organs, either as a hand-held device, or in a teleoperation framework.

Reviewing the technological challenges associated with the development of a laparoscopic palpation device

Minimally invasive surgery (MIS) has heralded a revolution in surgical practice, with numerous advantages over open surgery. Nevertheless, it prevents the surgeon from directly touching and manipulating tissue and therefore severely restricts the use of valuable techniques such as palpation. Accordingly a key challenge in MIS is to restore haptic feedback to the surgeon. This paper reviews the state-of-the-art in laparoscopic palpation devices (LPDs) with particular focus on device mechanisms, sensors and data analysis. It concludes by examining the challenges that must be overcome to create effective LPD systems that measure and display haptic information to the surgeon for improved intraoperative assessment.

Artificial tactile sensing approach in aortic-repair-laparoscopy: aorta cross clamping during surgery

Abdominal aortic aneurysm is one of the most common diseases of the vascular system for which the most definitive treatment is surgery. Laparoscopy is a primary method of minimally invasive surgery that could be useful in aortic repair surgeries. Although this method of surgery has significant advantages, the difficulty of exactly distinguishing the aorta from its surrounding tissues is its main drawback; this can cause many problems during the aorta cross clamping process. One of the most important limitations is that it is a time-consuming process; aorta cross clamping leads to increases in surgery duration. Artificial tactile sensing is an innovative technology aiming to make tactile data more available for surgeons, especially in situations where developments in technology make the surgeons less efficient. In this paper, considering the present problems during aortic repair laparoscopy, applicability of a novel tactile robotic system capable of cross clamping an artery during laparoscopy was evaluated. Having considered a small, 5-degree-of-planar-freedom robot and imitated surgeon's palpation using software, the path followed by the tip of the new tactile robotic system was extracted. It is shown that this new tactile robotic system is well capable of dissecting an artery from its adjacent tissues in a short time with an acceptable accuracy. The functional principles of the tactile robotic system capable of cross clamping the aorta during laparoscopy will also be presented.

Design and fabrication of a novel tactile sensory system applicable in artificial palpation

Force and position feedback are the two important parameters that are employed in different medical diagnoses and more specifically surgical operations. Furthermore, during different minimally invasive procedures, the ability of touch and force and position feedback are absent. In this regard, artificial palpation is a new technology that is employed to obtain tactile data in situations where physicians/surgeons cannot use their tactile sense. One of the most valuable achievements of artificial palpation are tactile sensory systems that have various applications in the detection of hard objects inside the soft tissue. Considering the present problems and limitations of kidney stone removal laparoscopy, the aim of this research is to design and fabricate a novel tactile sensory system capable of determining the exact location of stones during laparoscopy. This new tactile sensory system consists of four main parts: The sensory part, the mechanical part, the electrical part, and the display part. In this new system, due to the use of both displacement and force sensors, the usage limitations of previous tactile sensory systems are eliminated. The new tactile sensory system is well capable of finding the stone in the laboratory models through physical contact with the model's surface.