El MIT repasa en sus blogs algunas de las novedades tecnológicas en robótica que se han publicado durante el año 2009. Entre ellas destacan varios robots para usos médicos y algunos para usos en rehabilitación. Voy a comentar dos de ellos.El primero es la modificación del Falcon de la empresa Novit, un mando háptico al estilo de los Phanton pero que cuesta 20 veces menos ya que se utiliza para jugar a videojuegos. De esta manera se consigue un dispositivo robótico para rehabilitación por menos de 200 euros de forma que podría utilizarse en casa en programas de telerehabilitación supervisados por internet. La tecnología háptica se refiere al conjunto de interfaces tecnológicos que interaccionan con el ser humano mediante el sentido del tacto. Algunos dispositivos desarrollados para juegos tienen estas características, sobre todo en algunos joysticks y controladores de jvideouegos. se incluyen"tabletas vibradoras" ("rumble packs") con los que el usuario siente como hay irregularidades tales como un terreno desigual cuando conduce un automóvil. Sin embargo los dispositivos hápticos más avanzados son pequeños "brazos robot" que generalmente se llaman Phamtons (de la marca SensAble). Estos dispositivos ya se han utilizado para rehabilitación del ICTUS como comentamos al hablar de CURICTUS. Otras aplicaciones médicas son la simulación de laparoscopios y artroscopios que se utilizan para aprender estas técnicas quirúrgicas.
Dos dispositivos hápticos permiten que la persona que maneja este simulador de artrospio para hombro tenga la sensación de palpar y tocar tejidos mientras observa cómo la imagen digital muestra incluso cómo se deforman. Este se llama insightARTHRO VR® y es de GMV. pdf con más información.
Lo que hacen estos dispositivos es fuerza en los tres ejes del espacio para simular una resistencia en el momento en el que un puntero que vemos en una pantalla (por ejemplo) contacta con una imagen tridimensional. De esta manera se siente que se está tocando algo que no es más que una imagen en el ordenador. Es más fácil entenderlo probándolo una vez que leyendo una explicación. Hasta ahora costaban algunos miles de euros pero la empresa Novit ha desarrollado uno de bajo coste para utilizarlo como controlador de videojuegos de la videoconsola Xbox. De esta manera al sostener una raqueta en un juego de pelota podremos sentir la resistencia del impacto con la pelota por ejemplo o el peso de levantar diferentes objetos.
Falcon Novit y una demostración en un juego sencillo. Las posibilidades de utilizar estos dispositivos hápticos en terapia ocupacional y rehabilitación del miembro superior son practicamente infinitas. Por un coste muy bajo podrían tenerse muy diferentes "juegos-ejercicios" de terapia. Además permitiría medir de forma objetiva cómo se hacen esos ejercicios de bien, cuantos se hacen y si hay mejoría. El paciente no se aburriría durante la terapia con cubos de madera de colores sino que podría variar el aspecto del juego sin cambiar realmente el ejercicio que está haciendo. El mayor problema técnico es que permite movimientos en un espacio de trabajo muy pequeño. El mayor problema real para que se aplicaran estas cosas es el desconocimiento de la tecnología por parte de los responsables de dotar los servicios de rehabilitación y el rechazo por parte de los profesionales de la rehabilitación. Una vez más rechazo a lo desconocido. Sin embargo apostamos por el éxito de la tecnología háptica en rehabilitación.
¿Quieres un paso más allá? Haptic telexistence es un concepto aún más complejo. Tus movimientos se transmiten a un robot y las sensaciones tactiles del robot se transmiten a tu cuerpo consiguiendo así un avatar robótico. ¿Podremos abrazar a alguien que esté a kilómetros de distancia? Ya nos salimos del campo de la rehabilitación para entrar en el futuro de los sueños y la poesía... Cuando te escucho en el teléfono o te miro en la pantalla de videoconferencias mi tacto llora, no me llegan tu aliento ni tu olor pero eso no es tan doloroso. El tacto dormido protesta mientras mis ojos y oídos ríen.
Una demostración básica.
Una aplicación en un videojuego.
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1- Cheaper Robot Rehabilitation
Fuente original: www.technologyreview.comResearchers at George Mason University have turned a gaming device into a rehabilitation tool.
The device, dubbed My Scrivener, guides a patient's hand as she tries to spell out letters or write equations, helping her improve fine motor control. It can record about 100 data points per second to let a doctor analyze the patient's progress.
Sue Palsbo, founder of Obslap Research, modified Falcon, a 3-D force-feedback game controller made by Novint, a company based in Albuquerque, NM. A hinged arm (called a pantograph) attaches to the device and fastens on top of a regular pen or pencil, leaving room for a user to write with a comfortable grip. A physical therapist then uses My Scrivener software to decide on an exercise for the patient that lets her work toward creating clear, legible script (see video below).
Therapists regularly use this kind of repetitive training to improve motor control in patients, and the new prototype showed "dramatic" improvement for children with ADHD, according to the company, which says that it plans clinical trials this year. It adds that the device could even help diagnose mild physical or cognitive impairments.
Rehabilitation robots tend to be bulky and expensive, but the Falcon costs around $200 and sits on the corner of a desk or table. Another relatively cheap solution is the Wii, which is being used more and more in rehabilitation.
Etiquetas: robotics, rehabilitation
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La segunda novedad del año consiste en pequeños robots para una sola articulación a coste bajo, lo suficiente una vez más para plantearse poder tener estas máquinas en el domicilio o en un centro de rehabilitación rural o mediano.
2- Robo-Rehab at Home
Fuente original: www.technologyreview.comSmaller devices can help stroke patients regain function.
Friday, November 13, 2009 |
When a person suffers a stroke, the interruption of blood flow to the brain can cause lasting loss of function in the limbs. Persistent physical therapy can improve motor control by strengthening connections between the limb and brain. Now, a group at Northeastern University has developed several portable robotic devices that may aid in the rehabilitation process; unlike other rehabilitation devices, these may also let patients continue therapy at home.
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| Knee bend: This version of the AKROD knee device from Northeastern University was designed to help a patient regain motor function after a stroke. Credit: Biomedical Mechatronics Laboratory, Northeastern University | ||||||
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Stroke is the leading cause of disability in the United States; over two-thirds of stroke survivors are left with a disability, according to the National Stroke Association. Repetitive physical therapy that applies force to an affected limb can encourage motor signals to reach the brain and build new pathways of control. These exercises can help not just people recovering from a stroke, but also those suffering from other conditions, such as cerebral palsy or degenerative muscle diseases.
"It's well understood that the more you do it, the better you get," says Tariq Rahman, director of the Center for Orthopedic Research and Development at the Nemours Foundation and an associate professor at Drexel University.
Traditionally, physical therapists apply force to a limb manually: A group of therapists, for example, will help a patient walk on a treadmill by moving the legs and steadying the patient. In the last few decades, many researchers have looked to robotics for devices that provide forces to a patient's legs, arms, hands, or pelvis. Researchers hope that such devices will create smoother motion, react more precisely to patient improvements, measure progress more exactly, and make for a more comfortable, effective recovery. Several rehabilitation devices currently in use, such as Hocoma´s Lokomat machine or the University of Twente's Lopes, were designed to help people walk better--but these systems tend to be bulky and expensive.
The Northeastern researchers have developed devices for the knee, wrist, pelvis, and ankle that they say are portable and cheap enough to be rented by small rehabilitation or medical centers, and potentially even individual patients. The team kept the devices small by using a substance called electro-rheological fluid, which becomes stickier when an electric current is applied, thus creating a stronger resistive force in the device. The fluid contains particles that form chains when electricity is applied, turning the liquid into more of a gel in a few milliseconds.
"With this fluid, we are able to reduce the size of the mechanical components, like the brake," says Constantinos Mavroidis, professor and director of the Biomedical Mechatronics Laboratory at Northeastern. The group also says it's reduced the motor size by at least half compared to typical motors. In addition to the smaller size and reduced weight, the fluid-based motors also give a smoother motion, says Mavroidis. "You have the feeling that it's not really a mechanical device but a soft spring."
Rahman says that the Northeastern work looks promising. "We're always looking to make [devices] cheaper, lighter, smaller, and invisible. This is all in the right direction," says Rahman, who develops robotic rehabilitation devices for children with muscular disorders at the Alfred DuPont Children's Hospital. Most of the rehab devices Rahman sees are large and unwieldy and thus impractical for patients to use in the home.
| Smooth gripper: This robotic hand rehabilitation device uses a fluid that alters the resistance of the device when an electric current is applied. Biomedical Mechatronics Laboratory, Northeastern University |
Northeastern's second version of an active knee rehabilitation orthotic device, dubbed AKROD, uses electro-rheological fluid to create a brake on the device. AKROD consists of two lightweight circular braces above and two below the knee, with the power-generating fluid brake--containing gears and sensors--resting alongside the knee.
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An upcoming issue of the IEEE Transactions on Mechatronics reports on the Northeastern team's tests of the device on nine healthy patients. The subjects underwent standard stroke exercises and used AKROD as well. The researchers found that AKROD helped the subjects achieve comparable results to a bigger, commercial rehabilitation system called the Biodex System 3, which consists of a specially made chair, foot brace, and computer system.
A newer version of Northeastern's AKROD uses a NASA-inspired gear-based system instead of the special fluid. The gear-bearing drive lets the system lift a patient's leg to correct walking, rather than just apply resistive force. The device is still relatively small and light, due to a compact gearbox design. The device acts as if it has a virtual spring, say the researchers, using careful force to push the patient into the correct position.
The Northeastern team has also tested a rehabilitation device for the hand that's made of a gripper handle connected to sensors and gears. The device is driven by two actuators with the electro-rheological fluid, which increases or decreases its resistance as the patient uses the handle to navigate through a video game maze. The device exercises not only hand muscles but also forearm muscles, and records the force and position of the patient's hand. The researchers also created a version that can be used in an MRI to image the brain while a patient is undergoing the hand exercises. This could allow a doctor to see the effect of the exercise on a patient's brain, according to Mavroidis.
"We're so interested in this technology because it allows patients to perform repetitions of certain types of movements," says Paolo Bonato, Harvard Medical School assistant professor and director of the Motion Analysis Laboratory at the Spaulding Rehabilitation Hospital. Bonato collaborates with Mavroidis to test the devices with patients at the hospital. They are currently testing a small number of patients with the AKROD, pelvic, and hand devices, Mavroidis says.
"We can envision a home-care type of application where these devices are used by the patient in the home or the community," says Bonato.
The devices still need to go through clinical trials before they can be made available to the public.
Autor: Samuel Franco Domínguez
Etiquetas:
robotics stroke