STAMAS Images

STAMAS Workshop

STAMAS Workshop 29th October Spain

STAMAS Workshop

STAMAS Group Photo

New EU project STAMAS launched with a kick-off meeting at DLR.Preliminary design of the suit, upper and lower limb

STAMAS Group Photo

Suit

Preliminary design of the suit, upper and lower limb

Suit

Objectives

Goal

The consortium involved in STAMAS project has identified the need for developing a new type of astronaut’s suit, so called intelligent suit, with at least two functionalities: biofeedback monitoring and musculoskeletal degradation countermeasures based on feedback forces.

To address this goal, the consortium considers taking advantage of the promising benefits offered by smart technologies to make the electromechanical actuators developed for biofeedback suits more efficient, safer, smaller and lighter in order to adapt the technology to the on-board requirements for space.

 

Overall Objective

The overall objective of the project is to analyse the suitability and bring experience on the SMA and EAP based actuation technologies addressing terrestrial applications to research in new concepts of artificial muscles for biofeedback suits for astronauts, as an alternative to currently used technologies. To this end, the project Team proposes to focus on designing, developing and testing both a lower and an upper limb biofeedback suit demonstrator. Such demonstrators will incorporate two different types of artificial muscles subsystems in complementary configuration in order to attack the different pathologies originated due to microgravity (muscle atrophy, bone loss, and shifting of blood from the limbs to the chest and head). In practical terms, a biofeedback leg and hand will be developed. These parts of the human body have been selected for being the most critical and representative – in terms of engineering  complexity. In other words, a successful demonstrator of those devices will for sure represent an important achievement for the design and development of the whole intelligent suit.

A biosensor system will also be integrated. Its role will consist in alimenting in real time the control system of the suit with information about the user’s conditions, as far as both physiological and dynamic aspects is concerned, with the aim of regulating and optimizing the operational behavior of the actuators.

 

Specific Objectives

  • To give the scientific basis to provide an intelligent suit for on-board spacecraft use which is able to control, mitigate and even treat the health problems that could arise owed to microgravity and lack of mobility.
  • To bring experience on SMA/EAP technologies in the space domain, adapting the existing terrestrial technologies to space domain contributing to the substitution of the conventional hydraulic actuators.
  • To make progress in those control aspects dealing with artificial muscles, in order to stimulate its application in new and innovative frameworks, mainly in the space one.
  • To adapt different biometric sensors to the on-board space requirements to promote their applicability as an integral part of the astronaut’s equipment, improving its functionality and safety.
  • To develop two functional prototypes (active biofeedback leg and hand) which show the suitability of the selected technologies to be used in artificial muscles in space environment.
  • To analyse the feasibility and costs of the development of the complete suit, strengthening the future potential for these technologies in the space domain.
  • To generate innovative, valuable and beneficial results for the consortium and for the participating SMEs in particular.
  • To contribute to enhance the overall SME participation in FP7, and particularly in the Theme Space.
  • To obtain a significant technological demonstrator that will enable partners to show their technological capabilities, which will represent an important advantage at commercial level.
  • To carry out networking activities with important partners in the aerospace sector.

 

State of the Art

Human exploration of the Solar System is one of the most challenging targets included in the space programmes of the most important space agencies in the world. Specifically, in the last few years missions aiming at exploring beyond Low Earth Orbit such as the Red Planet complete the current missions programme of European Space Agency (ESA) and National Aeronautics and Space Agency (NASA). In these sense, exploring the Solar System beyond the Low Earth Orbit implies planning long space missions.

A critical aspect to take into account while preparing the long-term expeditions is to make sure that astronauts are prepared mentally and physically for the demands of long exploration missions before the launching and it is also imperative to maintain them in good health during and after the mission.

Unfortunately, nowadays the impact of the hazardous space environment on cosmonauts’ health is inevitable, consequently affecting the operational capabilities of the astronauts. So that, the development of the necessary elements which mitigate the pernicious effect of microgravity and motor inactivity is essential. For that purpose, before proposing any technical approaches, a better understanding of the pathologies associated to long stays in space is recommendable.

 

Detrimental Effects of Space Environment on the Human Body

The effects of weightlessness on the human body are well documented; in particular two valuable references are Dr. Gilles Clement’s edited books on the topic. Prolonged exposure of humans to a weightlessness environment can lead mainly to significant loss of bone and muscle mass, cardiovascular and sensory-motor deconditioning, and hormonal changes. Space biomedical researchers have been working for many years to develop countermeasures to reduce or eliminate the deconditioning associated with prolonged weightlessness. ESA Topical Team on artificial gravity formed in 2004 and held a Workshop at ESTEC in November 2005, chaired by Dr. Gilles Clement. Also, a Workshop on Artificial Gravity sponsored by NASA was organized in 1999 at Ohio, leaded by Laurence Young and William Paloski. Finally, IAA organized a Study Group on Artificial Gravity. However, despite current countermeasures (mainly pharmacological and regular exercises), most astronauts experience problems with balance orientation and fainting when standing during the first few days after landing. They also risk muscle tears and bone fractures and therefore must exercise and added degree of caution during their recovery period. Reducing the effects of microgravity on human body functions is therefore an open challenge.

 

Progress Beyond the State of the Art

The main challenge of this project is therefore the adaptation of mature SMA and EAP based technologies addressing terrestrial applications to develop new concepts of feasible artificial muscles integrated in biofeedback suits for astronauts, as an alternative to currently used technologies. This new active Biofeedback suit developed by the STAMAS consortium is based on the utilization of well-established SMA and EAP actuation technologies equipped. Next, a detailed description is offered explaining the principle of the technology and it provides progress beyond the existing technology.

It is outstanding the utilization of SMA / EAP technologies for designing an active system constantly operating and actuating on the human body as a function of the information received from integrated sensors. The integration of a set of sensors, the actuators and a precise control system will allow the suit to counteract the irregular distribution of the blood in the body during the mission.

It is also challenging the integration (through SMA /EAP actuation technology) of innovative and active functionalities into a space suit. Currently, space suits incorporate exclusively passive functionalities for the improvement and protection of the astronaut’s health. In this sense, the Biofeedback suit, will have the necessary autonomy to exert compressing or decompression on soft tissues. The magnitude of the exerted effort, its periodicity and its segmentation will be previously determined by the active suit according to the parameters and information provided by sensors.

In conclusion, by acting on different portions of the legs with the artificial muscles in the suit, it will be possible to modulate blood volume distribution between the upper and the lower part of the body. Thus the suit will serve at the same time as negative or positive pressure chamber although producing a compression of underlying soft tissues in any case. The effect could also be modulated acting separately on the two legs.

The functionalities previously described are primarily focused to counteract cardiovascular deficiencies during the mission. Regarding the deterioration of muscles and bones, the Biofeedback suit would be conceived as a structure with strands of modifiable stiffness able to oppose resistance to joint movement. This impediment would force muscle to contract vigorously.

As mentioned before, the set of sensor is a key part of the Biofeedback suit. These provide constant feedback to the control system, which will connect or disconnect the SMA / EAP actuators. The set of sensor consists of:

  • O2 saturation (reflective pulsoxymetry), two channels ECG, temperature.
  • Blood pressure meter based on the oscillometric method.
  • 2D echography system.
  • Surface electromyography.
  • Volume sensors for big groups of muscles (i.e. legs, chest, abdomen).