search.noResults

search.searching

dataCollection.invalidEmail
note.createNoteMessage

search.noResults

search.searching

orderForm.title

orderForm.productCode
orderForm.description
orderForm.quantity
orderForm.itemPrice
orderForm.price
orderForm.totalPrice
orderForm.deliveryDetails.billingAddress
orderForm.deliveryDetails.deliveryAddress
orderForm.noItems
Sensors & transducers


technologies such as in- depth finite element analysis (FEA), 3D printing and rapid prototyping. The team should also include electrical engineers capable of designing instrumentation solutions to meet strict signal conditioning requirements. This multidisciplinary approach results in a sensor element that meets the specifications in terms of nonlinearity, hysteresis, repeatability and cross-talk, as well as an electronic instrument that delivers analog and digital output, high sampling rate and bandwidth, high noise-free resolution and low power consumption, both equally necessary for a reliable turnkey haptics measurement solution. When it comes to the production floor,


material expansion, gage factor coefficient variation and other undesirable effects on the measurement result. For this reason, temperature compensation is paramount to ensure accuracy and long-term stability even when exposed to severe ambient temperature oscillations. The measures to counteract temperature effects on the readings are (a) the use of high-quality, custom and self-compensated strain gauges compatible with the thermal expansion coefficient of the sensing element material; (b) use of half or full Wheatstone bridge circuit configuration installed in both load directions (tension and compression) to correct for temperature drift and (c) fully internally temperature compensation of zero balance and output range without the necessity of external conditioning circuitry. In some special cases, the use of custom strain


gauges with reduced solder connections helps reduce temperature impacts from solder joints. Usually, a regular force sensor with four individual strain gages has upwards of 16 solder joints, while custom strain elements can reduce this down to less than six. This design consideration improves reliability as the solder joint, as an


Figure 2: Potential benefits for the healthcare stakeholders of a MIRS powered by haptics feedback


opportunity for failure, is significantly reduced. During the design phase it is also imperative to


consider such sensors to meet high reliability along with high-volume manufacturability, taking into consideration the equipment and processes that will be required should a device be designated for high-volume manufacturing. After all, the automated, high-volume processes could be slightly or significantly different than the benchtop or prototype equipment used for producing lower volumes. The scalability must maintain focus on reducing failure points during the manufacturing process, along with failure points that could occur on the field. Testing for medical applications is more related


to the ability of a measurement device that can withstand a high number of cycles rather than resist to strenuous structural stress. In particular for medical sensors, the overload and fatigue testing must be performed in conjunction with the sterilisation testing in an intercalated process with several cycles of fatigue and sterilisation testing. The ability to survive hundreds of overload cycles while maintaining hermeticity translates into a failure-free, high-reliability sensor with lower MTBF and more competitive total cost of ownership.


PRODUCT DEVELOPMENT GOES BEYOND SENSOR DESIGN CHALLENGES


Although understanding the inherent design challenges of the haptic autoclavable sensor is imperative, the sensor solution provider has to be equipped with a talented multidisciplinary engineering team, in-house manufacturing capabilities supported by fully developed quality processes and product/project management proficiency to handle the complex, resource-limited, and fast-paced new product development environment. A multi-discipline engineering team identifies


and translates customer needs into a cross- functional design as well as deploys novel approaches to old problems whose solutions are not easily found by a single, one-sided technical view. From this perspective, a design team must be compounded by mechanical engineers and able to navigate through the latest machine design


62


a comprehensive in-house manufacturing capability enables the sensor design company to control all aspects of the production process to better meet the demanding schedule and quality requirements. Moreover, strategic control of all manufacturing processes (machining, lamination, wiring, calibration), allows the design company to engineer sensors with a Design for Manufacturability (DFM) mentality. This strategic control of manufacturing boils down to methodically selecting the bill of material, defining the testing plans, complying with standards and protocols and ultimately strategising the manufacturing phase based on economic constraints. Quality is expensive, but lack of quality costs


even more. In medical applications where failure is not an option and tolerances are tight, the project stakeholders cannot afford to have quality as a meager department of testers whose job is to find defects before the customer does, but rather a rigorous and relentless commitment to a culture of excellence which permeates throughout all company processes, from design to shipping. Needless to say that the sensor solution provider must demonstrate its quality system is effectively implemented and maintained thru ISO 13485 certification as well ISO 17025 accredited testing and calibration laboratories. Time to market and cost control is paramount


when developing a medical device, and it also holds true for a haptic feedback sensor, considering the latter as part of the complex surgical robot supply chain. With that in mind, the company product managers must be fluent in agile/waterfall project management practices to integrate and streamline project activities, track controllable costs and, most importantly, ensure that information flows among multiple stakeholders promptly.


CONCLUSION


Surgical robotic companies are pursuing a marketable product that incorporates haptic feedback whereas few specialised sensor technology companies combine the competences to offer a measurement solution that meets all design requirements imposed by intra-abdominal force measurement in MIRS: miniaturisation, biocompatibility, autoclavability, high reusability and measurement accuracy.


FUTEK www.futek.com April 2019 Instrumentation Monthly


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68  |  Page 69  |  Page 70  |  Page 71  |  Page 72  |  Page 73  |  Page 74  |  Page 75  |  Page 76  |  Page 77  |  Page 78  |  Page 79  |  Page 80