Table of Contents IMPR PROVI VING M MED EDICAL CAL D DEVI - PDF document

Table of Contents IMPR PROVI VING M MED EDICAL CAL D DEVI VICES CES W WITH TH F FORCE S CE SEN ENSING T TECHN HNOL OLOG OGY ................................ ................................................. ................. 3 S UMMARY .............................................................................................................................................. 3 M EDICAL D EVICE A DVANCEMENT ...................................................................................................................... 3 T HE I MPORTANCE OF Q UANTIFIABLE D ATA ............................................................................................................ 3 S HIFT T OWARDS I NTELLIGENCE ....................................................................................................................... 4 F ORCE S ENSING T ECHNOLOGIES ....................................................................................................................... 4 T HE R OLE OF F ORCE S ENSORS ........................................................................................................................ 5 S URGICAL D EVICES .................................................................................................................................... 5 M EDICAL T RAINING D EVICES .......................................................................................................................... 8 C ONCLUSION ........................................................................................................................................... 9 REF EFER EREN ENCES CES ................................ ................................................................ ................................................................ .................................................. .................. 10 10 05/14/13 Improving Medical Devices with Force Sensing Technology (Rev A) 2

IMPROVI ROVING NG M MEDICA CAL D L DEVI VICES W S WITH FORCE FORCE SE SENSING T NG TECH CHNOL NOLOG OGY SUMMARY Design engineers integrate force sensors into medical devices to create smart tools that produce quantifiable and actionable data. These intelligent devices help to eliminate guesswork, create consistency, and improve patient outcomes. Force feedback is an increasingly valuable feature in the medical device market and a large array of products and applications use force feedback. MEDICAL DEVICE ADVANCEMENT The medical device market in the United States is a $60 billion industry and still growing significantly today. The main target demographic for the medical device market is not the patients themselves, but healthcare providers who are seeking new and innovative medical devices to improve basic procedural outcomes and patient quality of life. In the past, physicians relied heavily on simple tools and their own interpretations to best diagnose their patients. During these times, resources were scarce, and the variety of medical devices doctors have available to them today simply did not exist. Today, with the progressive nature of healthcare, the world of modern medicine is transforming. Over the past century, the innovative minds behind designing new medical devices have narrowed the focus toward designing tools that produce quantifiable data that in turn helps improve the integrity of the medical practice. In recent years, the growing partnership of the engineering and medical sciences has sparked numerous advances in medical devices and technologies across the board. THE IMPORTANCE OF QUANTIFIABLE DATA Although there have been many significant advancements in the field of medicine in past decades, some medical examinations and diagnoses are still based solely on subjective interpretations and the studied knowledge of the physician. As the medical field continues to evolve, so does the need for a more systemic approach to treating patients efficiently and effectively. Engineers, alongside physicians, have learned that technology can help mimic the actions of doctors while also measuring the specific assessment variables. For example, in the case of physical therapy; specifically, manual evaluations, the amount of force applied by practitioners can vary as greatly as 500% and reach potentially dangerous levels. Therefore, consistency among therapists in order to obtain adequate feedback without harming their patients is crucial (Jacuinde, G. & Tuttle, N). This hands-on treatment involves skilled hand movements, taking into account both location and speed, applied by the therapist to improve the mobility and function of the targeted muscles and tissues. In recent years, medical researchers and therapists have sought after a device that would provide minimal interference to their techniques, while ensuring the proper amount of applied force to a patient. Design engineers were able to construct a glove incorporating small, thin force sensors, simple wiring, and custom software, to develop a way to measure the force applied between the user and the patient directly. When applying the glove to a surface, the sensors in the glove relay a signal that the custom software interprets and converts into a force value. The software displays a force reading as both an instantaneous value and time series graph. These outputs allow the user to not only feel, but also see the amount of force they are applying, and adjust appropriately. Doctors have become increasingly dependent on medical devices to assist them in their field studies and day-to-day practice. The design and function of these tools allow doctors and surgeons a clearer view of their patients’ health and progress. These medical devices are ultimately able to produce quantifiable data that leads to more supportive diagnoses and better data-driven adjustments. The overall quality of life improves as a direct result of studying the data yielded. 05/14/13 Improving Medical Devices with Force Sensing Technology (Rev A) 3

SHIFT TOWARDS INTELLIGENCE The ability to integrate and apply electronics to simple medical tools has changed the face of the medical device industry dramatically. Adding intelligence to these devices increases the effectiveness of patient care and provides constant, consistent monitoring of a patient’s health. The growing field of biomedical engineering is a key attribute to these innovative advances in surgical tools, as well as assisted living and medical training devices. When it comes to designing a new product or tool, design engineers focus greatly on the most efficient, cost effective components to integrate into their medical device design. Whether using the tool for a diagnostic, therapeutic, or surgical purpose, the engineer must consider a variety of factors when constructing a new device. These factors include accuracy, size, cost, and more importantly to the medical world, safety and consistency. Doctors are looking for reliable tools with high accuracy, so design engineers must find a product that fits the needs of both the doctor and themselves. FORCE SENSING TECHNOLOGIES One of the most important elements of a medical device is the feedback it provides the person using the tool, whether it is a primary care physician, surgeon, or patient. The device design must support a flow of communication between the patient’s body, the tool used, and the doctor reading and analyzing the output. Force feedback has become an important focus in the design of new medical devices due to these factors. The human body is a sensitive object, so the amount of force applied by a doctor or medical instrument, whether it is the case of physical therapy or surgery is a key factor for consideration. There are a few ways that force can be measured, but depending on the context of the application, some force sensing technologies prove more ideal than others do. Figu Fi gure 1 e 1: Lo Load C Cel ell Fi Figu gure 2 e 2: St Strain G Gauge M ge Mea easurem emen ent Load cells, strain gauges, and piezoresistive elements are devices used to measure force. The most well known device used to measure force amongst researchers and engineers is the load cell. Load cells can use a variety of technologies to sense loads, but are bulky in size; making them difficult to design into an application where lightweight and small size are priority. To obtain force measurements, engineers commonly use strain gauges. Strain gauges are smaller than load cells, but yield measurements that are a result of indirect force measurement drawn by correlating the strain of an assembly with a load. Both technologies also require expensive electronics to obtain accurate force readings. In recent years, a different approach to force sensing technology has become commercially available. The generic term for this device is the tactile force sensor. Typically built on a flexible circuit material, these sensors are sensitive to touch. Tactile sensors are thin, lightweight, and flexible; making them ideal for integrating into a variety of products, including medical devices. 05/14/13 Improving Medical Devices with Force Sensing Technology (Rev A) 4