Feasibility of Shape Memory Alloy Wire Actuation for an Active Steerable Cannula

Konh, Bardia; Datla, Naresh V.; Hutapea, Parsaoran

doi:10.1115/1.4029557

Cited by 19 publications

(11 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The amount of heat required for the SMP element and the consequent temperature that would be generated due to a specific voltage have been discussed in our previous study [8]. Also, there are some other information about the amount of current, duration, temperature-load, required time for deformation/recovery listed in our previous work [1]; via a different prototype but similar actuators.…”

Section: Methodsmentioning

confidence: 98%

See 1 more Smart Citation

Design and Fabrication of a Robust Active Needle Using SMA Wires

Konh

Podder

2017

2017 Design of Medical Devices Conference

Self Cite

View full text Add to dashboard Cite

Shape memory alloy (SMA) based active needles [1] have shown the potential to introduce remarkable improvements to many percutaneous needle-based procedures such as thermal ablation, brachytherapy and breast biopsy. Brachytherapy for instance is a common procedure to treat early stage prostate cancer because its superior clinical outcome. Prostate cancer is sex specific and only affects males; it is more prevalent in elderly males, ages 65–74 years old [2]. There is projected to be a 24% increase in cancer cases for men by 2020, this would mean approximately 1 million new cases each year [3]. There was a study in 2015 [4] that examined the needle placement accuracy for brachytherapy procedure while implementing the use of a 3D navigation system, Surgical Planning and Orientation Computer System. The study examined the Target Registration Error (TRE) for single and multiple needle placements. Analysis of the 250 different targets showed a mean Target Registration Error for single needle applications of (1.1 ± 0.4 mm), (0.9 ± 0.3 mm), and (0.7 ± 0.3 mm) in the x, y, and z directions, respectively. The maximum deviation was found 2.3 mm. In another study by Podder et al. [5], the effects of dose distribution has been discussed which has a high influence on the clinical outcome. The study shows that the curvilinear approach by the active needle would introduce the potential for improving dose distribution, reducing number of needles and resulting is better clinical outcome. Actuating the surgical needles for higher accuracy, SMAs are considered as suitable actuators [6] because of their lightweight, high force and energy density. However, SMA actuated needle will be more complex and may incur additional inaccuracy; thereby after development of a robust active needle, control studies sound very necessary. The focus of this work is to introduce an innovative design of an active needle, and to fabricate the device to demonstrate its capability of creating a high maneuverability at the needle tip. This design of the active needle privileges from actuation of a comparatively long SMA wire to create a considerable amount of deflection, while minimizing the tissue rupture. Most of the needles today are made of stainless steel, titanium or Nitinol; they are ensured to be sturdy enough to puncture the tissue and overcome its resistance during insertion. This would limit the flexibility of the needles. In our previous designs [7,8], a joint element was included in design to provide more dexterity to the needle’s structure. Despite of the fact that this soft element increased the needle’s flexibility; the design introduced a high tissue rupture during actuation because of the gap between the body of the needle and the SMA actuator. The amount of rupture was increasing with larger deflection of the needle. This work decreases the rupture to a reasonable amount while even a higher deflection compared to our previous design is achieved. Table 1 lists general specifications and approximations of dimensions and requirements that have been tried to be addressed in the current design as much as possible. There will be still future work to meet some other factors discussed at the end of this study.

show abstract

Section: Methodsmentioning

confidence: 98%

“…Shape memory alloy (SMA) based active needles [1] have shown the potential to introduce remarkable improvements to many percutaneous needle-based procedures such as thermal ablation, brachytherapy and breast biopsy. Brachytherapy for instance is a common procedure to treat early stage prostate cancer because its superior clinical outcome.…”

Section: Introductionmentioning

confidence: 99%

Design and Fabrication of a Robust Active Needle Using SMA Wires

Konh

Podder

2017

2017 Design of Medical Devices Conference

Self Cite

View full text Add to dashboard Cite

show abstract

“…The primary concept of active surgical needle ( Fig. 1) was suggested by Konh et al [6] where the feasibility of using SMA wires to actuate the surgical needles was shown. The SMA wires, i.e., Nitinol wires in our design, supply bending forces to the needle body to guide the needle through desired trajectories inside the tissue.…”

Section: Introductionmentioning

confidence: 99%

Design optimization study of a shape memory alloy active needle for biomedical applications

Konh

Honarvar

Hutapea

2015

Medical Engineering & Physics

Self Cite

View full text Add to dashboard Cite

“…The proposed self-actuated MitraClip locator device uses active Shape Memory Alloys (SMAs), Nitinol wires, in order to expedite surgical procedures with a higher precision. SMA wires have been used in medical devices safely and effectively [4,5]. Fig.…”

Section: Introductionmentioning

confidence: 99%

Design and Fabrication of a MirtaClip Locator Prototype for Percutaneous Transcatheter Mitral Valve Repair System

Konh

Woo

Miller

2017

2017 Design of Medical Devices Conference

Self Cite

View full text Add to dashboard Cite

Mitral Regurgitation (MR) is a malfunction of the mitral valve where the blood flows backward because of improper closure of the valve. The blood flows back through the mitral valve to the left atrium during the contraction of the left ventricle. This condition usually causes shortness of breath, fatigue, lightheadedness, and a rapid heartbeat. It is estimated that 2% of the global population have significant mitral valve disease. In US, more than 200,000 patients are diagnosed with this condition each year [1]. Current treatments include anticoagulation medication, and surgeries to replace or repair the dysfunctional mitral valve. Open heart surgery has been the conventional approach to repair or replace the mitral valve. However, for a large percentage of patients (almost 30%), open heart surgery carries increased risk of mortality and morbidity due to their advanced age and dysfunction of the left ventricle [2]. Recently, less invasive, transcatheter approaches to mitral valve disease have been developed to decrease the surgical risk for these patients. [3]. One of the approaches that has recently shown promising outcomes is the placement of a MitraClip system (Abbott Vascular, Inc., Santa Clara, California) to stop or decrease the undesired leakage. MitraClip is a metal clip coated with fabric that is implanted on the mitral valve leaflets to allow the valve to close more completely. After clip placement, blood flows in an assisted fashion as the mitral valve opens and closes on the either sides of the clip. The whole procedure for placement of the MitraClip in Transcatheter Mitral Valve Repair (TMVR) takes 2 to 3 hours under general anesthesia. A transesophageal echocardiogram is used to observe the blood flow and to trace the placement of the clip. A catheter is guided inside the femoral artery after percutaneous access is established. Then a guide wire is inserted to reach the mitral valve. At this time the MitraClip is threaded into the target position between the leaflets, and then, the guide is removed. Precise placement and orientation must be achieved at this point to best secure the clip with the minimum leakage possible. Since the implantation is being done inside a beating heart, this precise placement is the most challenging part of the surgery. Currently trial and error along with precise measurements are being utilized to find the best position. This work introduces an innovative MitraClip locator device based on the most advanced materials and actuators to assist in the positioning of the MitraClip during implantation; this would potentially facilitate the most challenging and improtant step of the procedure. Currently, doctors are spending most of their surgical time (roughly 90 min) finding the correct orientation for the clip. The proposed self-actuated MitraClip locator device uses active Shape Memory Alloys (SMAs), Nitinol wires, in order to expedite surgical procedures with a higher precision. SMA wires have been used in medical devices safely and effectively [4,5]. Fig. 1 shows the schematic picture of our novel design that includes evenly distributed SMA wires inside a shaft to enable orientations in multiple directions. This design is proposed as a scaled model for preliminary testing. After thorough testing and evaluation on this model a real size prototype will be made for the real application. This work presents a detailed design of our innovative device. This device has been fabricated and tested to show the proof of concept. The main purpose of this work is to show the feasibility of achieving movements in multiple directions using three shape memory alloy wires. As a long term plan, the authors aim to have this mechanism (while its accuracy and safety is assured) attached behind the MitraClip to facilitate controlled, accurate positioning.

show abstract

Feasibility of Shape Memory Alloy Wire Actuation for an Active Steerable Cannula

Cited by 19 publications

References 38 publications

Design and Fabrication of a Robust Active Needle Using SMA Wires

Design and Fabrication of a Robust Active Needle Using SMA Wires

Design optimization study of a shape memory alloy active needle for biomedical applications

Design and Fabrication of a MirtaClip Locator Prototype for Percutaneous Transcatheter Mitral Valve Repair System

Contact Info

Product

Resources

About