kstrausser

So you want to be an intern…

It’s internship application season!  As an intern hiring manager, I have the task of reading hundreds of internship resumes every year.  Hiring interns is challenging and I find it much different from hiring full time employees.  Interns often come with little to no experience and thus we are trying to determine from their resume if they have sufficient skills to accomplish the tasks we have planned.  It is also in our best interest to utilize the internship as an extended interview, so those who would be a good fit for full time work after graduation are attractive candidates.  I often read over 500 resumes for 1-2 positions, so you can imagine that it is hard to stand out in a crowd.  In order to make yourself most attractive as a candidate, it is critical that your resume conveys what the hiring manager needs to know about you.  Askamanager.org is one of my favorite sources for all things job related, but Alison Green’s advice on resumes is a great resource.  Since she mostly focuses on full-time employment, here are some of the additional things I recommend to internship seekers.  In my next post, I’ll focus specifically on exoskeleton jobs! 

  1. Demonstrate your skills.  For full time employment, this is often done by sharing accomplishments at previous jobs.  Most interns have very few relevant job experiences, so it is critical to demonstrate this skill by talking about course projects and club projects.  Be specific about what you accomplished and what skills were required to do so. Brag! Show off!  This is your chance to tell me what you can do.
  2. Do projects.  I am hiring engineers, and while being able to pass tests and solve problem sets is indicative of skill, it is easiest for me to see how you will succeed in the role if you have been involved in hands-on projects.  If your coursework doesn’t include projects, I highly recommend joining a club or other activity that does or even apply these concepts to projects on your own.  Furthermore, it is unnecessary to list your courses.  I know what an accredited engineering curriculum looks like, so use that space to show me what those courses taught you.
  3. Demonstrate why you want the job.  I do NOT mean an objective statement that says: “I want to be an intern at X company”.  I mean show me through your projects, interests, and courses that this is an interesting field to you; that this is a potential stepping stone for your future career.  This is especially true if you are early in your college career or applying from a non-traditional major for the position.  Given the number of resumes I have to review, I don’t always have time to read full cover letters, so it is best to include this information somehow on the resume itself though expanding in a cover letter is important. 
  4. Make your resume professional.  Proofread!  This is critical for any job level, but in the sea of internship applications, small things can make your resume stand out.  Don’t let it stand out for the wrong reasons.  I recommend submitting a pdf format resume and including some minimal formatting.  Do not go overkill, but a bit of polish shows a level of professionalism and care.  
  5. Apply for THIS job.  As an intern applicant, I too took the spaghetti approach- throw out a bunch of resumes and hope one sticks.  This will sometimes work and a well-written resume will be applicable to multiple jobs; however to optimize your chances, it is worth spending some time with the job description and the company webpage to make sure that you have addressed the concerns that this hiring manager may have.  I, unfortunately, will get to the phone screen level with a far fewer percentage of intern candidates than full time candidates, so it is even more critical that you sell yourself through your resume.

Applying for internships among problem sets, exams, projects, and other college life can be challenging.  It can also be very frustrating when you know that you are just one of many applicants in a pool.  However, taking the time to put your best foot forward can reward you with a great summer experience and open the door to future opportunities.  

Advice from Rosie

During World War 2, many women joined the war effort by taking jobs traditionally held by men.  The women worked in factories and shipyards as drafters, welders, boilermakers, and more.  These women became known as “Rosies”.  The now iconic image of the rosie with the red bandana and the words “We Can Do It!” was an inspirational image to boost worker morale at the time, but now lives on as a symbol of women in the workplace, women’s empowerment, and the grit and determination of women. 

The iconic Rosie the Riveter image

My office is located around the corner from the Rosie the Riveter WWII Home Front National Historic Park, in the home of the original Ford Factory.  It is an inspiration to work where these women broke down so many barriers.  

At the Visitor Center, I have had the privilege of hearing Ranger Betty Reid Soskin (https://en.wikipedia.org/wiki/Betty_Reid_Soskin) share her story as a black woman working on the home front during the war.  We frequently hear about the welders and riveters, but we don’t hear about the Rosies, quietly toiling away in the offices, segregated because of their race.  Betty emphasizes how important it is that everyone’s stories are told and remembered.  She has remarked “what gets remembered is a function of who’s in the room doing the remembering”, and these words continue to ring true.  Her legacy and the legacy of so many other black women is known because she fought for her seat at the table to tell her story.  After hearing Betty’s story, I have been inspired to not only share her story but also to hear others and to try to spread their message.

I was also able to hear Mae Krier (https://www.washingtonpost.com/lifestyle/2020/07/21/mae-krier-rosie-riveter/) share her story.  Mae and other Rosies were on their way to the Pearl Harbor anniversary in December 2021 and made a stop in California.  I asked Mae what she would have me share with other young women who want to follow in her footsteps.  Her advice was simple and yet poignant: “We have brains too.” This statement, which seems so obvious, speaks to a time when women’s abilities were doubted with such regularity that just reminding women that they too can think is critical.  Have we come far enough from this?  We are so often plagued by imposter syndrome or told by others that we are not enough.  In these instances, remember Mae’s words.  She also said: “Don’t give up.  We learn more from our mistakes”.  As an engineer, this advice resonated with me.  The difference between an ok engineer and a great engineer is one who can take the lessons from the failures and learn from them.  Whether it be a failed component or a bug in code, if we don’t use these as learning opportunities, we are missing chances to grow, improve, and embrace the spirit of the Rosies that paved our way. How you learned from your mistakes to make your project or yourself better makes for great reading on resumes.

Me with 3 other Rosies at the Mae Krier event.

Failure is not the opposite success; it is part of success.

                           -Arianna Huffington

Time for Rehab

In physical therapy, time is everything.  Studies have shown that increased repetitions of exercises improve outcomes, which suggests more and longer therapy sessions.  However, time costs money in the form of therapists, rehabilitation gym space, and time away from other activities.  Therefore, any device which seeks to improve rehabilitation through higher repetitions must do so in the constraints of time requirements. Time is the enemy, but it is also an opportunity.  Rehabilitation robotics are able to address many of the challenges to repetition with the allotted time, but care must be taken to not lose those benefits with setup costs. The timer on the therapy session doesn’t start when the patient starts walking, but when he or she enters the gym. 

One of the most fundamental concepts is that walking in an exoskeleton can increase the number of steps that a patient can take during a session.  The device does this by minimizing the need for therapist support (manually moving the leg, providing trunk support, etc) and by providing enough assistance to allow the patient to be successful in each rep.  I see patients who had struggled to take 10 steps in parallel bars walk hundreds of steps in their first EksoNR session!  They are upright, moving, retraining those neural pathways to execute a step, and are supported to keep their body in the proper alignment while minimizing strain on the therapist.  

There is much more than walking that we must consider while designing a robotic exoskeleton around donning and doffing the device, programming it, and making clinical decisions that optimize outcomes.   We as engineers cannot overlook these aspects that contribute to or detract from our product..

One summer internship,  I was tasked with timing every step on the manufacturing floor to determine where time could be saved.  While those I was observing didn’t appreciate the teenager with a stopwatch scrutinizing their every move, I learned a lot from this experience.  I saw the importance of breaking down each part of the process to understand where time is used and I learned the importance of doing that in the real environment.  So often, we speak to therapists and they say “Oh, it doesn’t take long to set up.” And that’s true when I know my settings and have tools in hand.  But in the clinic, as you observe a session (stopwatch in hand), you see the seconds tick by as they search for a tool or as they have to re-check the sheet for a setting after being interrupted by a colleague asking about the next patient.  By breaking down these time losses into small pieces, we can find solutions.  Sometimes it is as easy as redesigning a  form so that it is easy to glance at a setting or adding a hook for a tool.  Other challenges may require more complex solutions, but the more we focus on solving these challenges, the more time that therapists can spend with upright and walking patients.

Exo or Not?

There are a lot of types of robots out there, and while I’m partial to exoskeletons, which one I would choose to build depends fully on the task at hand.  There are many places where other robots have the advantage over exoskeletons.  In more static environments, arm robots provide speed and accuracy that humans cannot match.  In robotic-assisted surgery, robots enable smaller incisions and more stable control of the end effector.  And in terrains where humans may not be able to go, such as space or the bottom of the ocean, robots become our means to access these places.  To our credit, we engineers have built robots that have extended our reach on Earth and throughout the universe and augmented our human skills to perform incredible feats. However, there are some instances where we engineers have missed the mark..

When carrying supplies into a warzone, we thought it was a waste of energy to have a soldier carry their own gear.  In response, Boston Dynamics developed Big Dog, a robot that could carry a lot of weight to ease a soldier’s burden of carrying.  Big Dog was a brilliant robot with complex sensing and actuation that allowed it to remain stable when kicked and move over rough terrain. However, it turned out that Big Dog was too noisy for the job and soldiers wanted to keep their essential gear on their bodies where they cannot be separated from it.

Big Dog Robot, Boston Dynamics (bostondynamics.com/legacy)

In response, HULC and GaurdianXO (Sarcos) were created to allow soldiers to carry the load right on their bodies, keeping it safe and close.  Utilizing some of the power of the soldier’s body to accomplish the tasks meant less power was needed by the robot, which resulted in a quieter device that fulfilled the user’s needs.

Fulfilling the user’s needs should be our priority. For some assembly environments, we have created robots that can paint, move parts, tighten bolts, and weld seams. These robots fulfill the user’s needs usually by sitting in one place and doing mind-numbing, joint-damaging repeated work.  In other environments, this is not what is needed. When assembling a ship, for example, a base for an arm robot cannot be erected just to finish the welds along the inside corridor or to carry the cabling from one end to the other.  In this instance, exoskeletons fulfill the user’s needs. Exoskeletons fit close to a person and allow for assistance without the large footprint or installation requirements.  The lack of large footprint and installation is also a benefit in the medical rehabilitation setting. Exoskeletons can fulfill the user’s needs in a wide variety of situations.

One of the most important reasons to utilize exoskeletons and other robotic devices is to leverage the user. As with all engineering, and robotic engineering in particular, it is critical that we first examine the requirements of the user before determining what type of robot to build, what that robot will do, and what the robot needs to look like.  The best way to do that is get out from behind our computers, get out of our labs, get out of our offices and visit our users in the environment they need our device. We need to listen carefully to what they are saying and ask them questions and listen to their answers. This is difficult, expensive, and time consuming, but the effort pays off in the product people want to use.

Do Robots get the “Twisties”?

In watching some of the Olympic events and the Paralympic events, you can’t help but be amazed at the human body.  There has been a lot of discussion about Simone Biles experiencing the “twisties” and how that  danger puts an athlete in danger..  While my own experience as a gymnast didn’t get much past cartwheels, I am acutely aware of what this phenomena can do.  Humans utilize proprioception, which is the awareness of the position of the body, to control our bodies.  When that awareness is altered, we can have trouble with a host of things such as reaching, balance, and walking (not to mention executing multiple aerial flips).  Robots also have a concept of proprioception through sensors and calculations.  Exoskeletons aren’t doing backflips (though you can see some impressive gymnastics from Boston Dynamics’ Atlas here: https://www.bostondynamics.com/atlas), but accuracy and control of the motion they are executing is still important.  When I design the gait trajectory of an exoskeleton, the placement of the foot in space throughout the gait is very important.  If it is too high and the human cannot match the awkward high-step gait; too low and the human will trip when their foot does not clear the ground.   Toe clearance can be as low as about ½”, so there is not a lot of room for mistakes.

If we want to know where the exo’s toe is, there are a number of ways to do this.  One is to directly measure the distance from the ground.  To do this while walking, you need something like a laser range sensor or sonar sensor.  These can be difficult to ensure that your measurements are accurate on a variety of surfaces. 

You can also use IMUs (inertial measurement units).  These utilize accelerometers and gyroscopes to calculate orientation and acceleration and these measurements can be integrated to determine position.  These sensors are subject to drift, though there is extensive research on how to mitigate this problem which I will not cover here (but it’s worth a Google search if you’re interested!).

One of the most common ways to measure toe location uses forward kinematics.  Forward kinematics takes the known position of one link of an object and calculates the end position using the known lengths and angles of each.  

Take for example, a 2-link robot arm.  The base is fixed on the ground, so we’ll call that (0,0).   Each of the links have an angle and a length associated with them.  If we want to calculate the position of the end of the robot, we use trigonometry to calculate the X and Y component of each link and then add them together.

A 2-link arm

    \[x = l_1cos(\theta_1) + l_2cos(\theta_1+\theta_2)\]

    \[y = l_1sin(\theta_1) + l_2sin(\theta_1 + \theta_2)\]

But what if the robot has the “twisties” and the measurement of the first angle is off by just a little bit?  Maybe the sensor calibration wasn’t quite right or the mechanism got loose and slipped a bit or the beam isn’t perfectly stiff and so it sags a bit through the length?  Let’s a assume an error of just 5°.  It may not look like much to our eye, but it can mean the difference between successfully picking up an object or colliding with it.

Let’s put some numbers in just to see what difference a mere 5 degrees makes. Let:

    \[l_1 = 12 in\]

    \[l_2 = 10 in\]

    \[\theta_1 = 30^{\circ} \]

    \[\theta_2 = 15^{\circ} \]

In our original calculation, y = 13.07 inches.

However, if sensor is off by 5°, we have to adjust the measured angles…

    \[\theta_1 = 25^{\circ}\]

    \[\theta_2 = 15^{\circ}\]

Now y = 11.5 in.

When we look at the kinematics of a body, we usually start from a foot that we know is on the ground and work our way up that leg and down the other to determine the foot position.  Over this many links, small errors in our perception can cause big problems.  5° is as simple as not measuring the flexibility of a link or accumulated small errors due to the inaccuracy of sensors.  Given this, I am constantly amazed by our bodies and our ability to do things as seemingly simple as walk across a room to as complex as flips on the balance beam.  We engineers have quite a challenge ahead of us!

Fitting an Exoskeleton

Exoskeletons derive their name from the exoskeletons we find in nature.  Those seen on insects fit precisely along the body, enhancing the strength of the insect while allowing for motion.  The walking stick shown here gains strength from this supportive structure, but the joints are intricately developed to work with the muscles and tendons to allow for a very large range of motion at the joint.

photos: ©Matthew Strausser IG: @strausserphotography

A rehab exoskeleton must likewise become an extension of the patient, working with both their own muscles and the actuation of the device.  Therefore, the joint alignment and sizing is critical to comfort and functionality.  But our challenge of time remains and we must consider the tradeoffs between accurate sizing and speed.  If we adjust every aspect of the device perfectly, the device will fit snugly, but each patient will either need custom pieces or set up times will become prohibitive.  If we do not have sufficient resolution, however, we risk pressure sores, abrasion, discomfort, or muscle strain.  We as engineers are thus challenged to develop adjustments that are fast, accurate, and secure and use compliance where rigid attachment may not be necessary.

EksoNR utilizes adjustments at the upper and lower leg and hip width as well as velcro soft goods to achieve a safe and comfortable fit while being relatively quick to set up. 

Next, the patient must get into the device.  For some devices, the patient can put on pieces while sitting or may need to put an AFO or similar brace into their shoe.  In others, they transfer into the device, and still for others a bodyweight support system may be used to help get that patient in. Locking in the adjustments may require specialized tools, and we must consider their maintenance as well.  It is advantageous to have adjustments that an untrained user, such as a therapy aid, can make as this decreases the time out of the therapists’ session.  We also consider what adjustments may need to be made during the session and how to accomplish those with minimal disturbance.  We also have to provide the therapist a way to determine if the adjustments are correct whether through visual clues, messages from the device itself, or tests that can be run to check.

Currently, most devices use traditional mechanisms for locking and positioning, such as nuts and bolts, friction clamps or pins.  Improved materials and manufacturing processes will provide us new opportunities for improving and streamlining adjustments. For example, printing carbon fiber or even metal components allows us to gain strength while using intricate patterns for tool-less locking.  There are also soft sensors and soft actuators in development that will improve fit and self-adjust support and bracing.  The challenge here becomes balancing the complexity and cost with the benefits gained in terms of therapy outcomes.  As these technologies advance, the balance may come to tip in the favor of additional sensing and robotic controlled adjustment, but I will leave that for a future design project.

The Legacy

The Legacy

I was introduced to exoskeletons as a graduate student at the University of California, Berkeley where I was fortunate enough to study with Professor Kazerooni whose work focuses on enhancing human capability through exoskeletons.  The lab developed devices like BLEEX, which give able-bodied individuals added strength by wrapping a mechanical structure around the body and adding power.  

The initial devices were large and required offboard power or loud engines which limited their use.  Then the lab developed HULC, the Human Universal Load Carrier, which was a breakthrough exoskeleton developed to help soldiers carry load through unknown terrain. 

 It followed the same model of BLEEX and other exos in mimicking and adding to the body’s structure, but it utilized gravity and joint alignment and actuation in a way that enabled the device to be run off of on-board power.  HULC’s design transfers the load weight around the human body to the ground and added power to the legs only where needed. Professor Kazerooni saw that this technology could be extended to add power where there was a deficit, not just where excess power was needed.  My colleagues and I began work in developing the concept of a medical exoskeleton and were met with many challenges- some expected, some not.  I was excited by this challenge and the potential to help those who had suffered from a stroke or spinal cord injury, and while I knew the challenge would not be an easy one, it took some time to understand the difficulty of transitioning from developing a device for able-bodied load-carriage applications to one that provides mechanisms for gait rehabilitation.  

An exoskeleton for load carriage does not need to provide assistance in all directions.  Gravity helps with knee flexion (like when squatting down), so power can be limited to extension.  In a rehabilitation device, the patient lacks power or control in both flexion and extension so both must be powered.

In a device built for rugged terrain, the soldier must have full flexibility.  Therefore, joints that are not controlled must be free, such as hip abduction to allow for side-stepping.  In therapy, we must control all joints even at the cost of reduced freedom by locking them out completely.  

HULC was built for use by the army, to be used outside and with trained soldiers.  Service could be completed by the users, so regular maintenance was not an issue therefore allowing us to utilize hydraulics to optimize the location of components.  In the medical setting, however, regular maintenance and potential leaks were not acceptable while the distribution of weight was less critical, so a more traditional motor system was chosen.  

A soldier must be able to quickly take off the exoskeleton for full maneuverability in case of emergency or attack, thus the robot has minimal connection points.  In a clinical setting, the patient must be tightly coupled to the device for safety and while donning and doffing must be fast, it does not require the speed a military device does.  However, the user must be able to transfer into it with limited to no motion in the legs.

There are many additional challenges that face rehabilitation exoskeletons.  While some are similar to those faced in the military or industrial applications, many are unique to the users and settings found in rehab.  When I entered that lab more than a decade ago, I did not realize how much this problem would draw me in and become my passion.  The challenge of building a robot for gait rehab is one that challenges the engineering mind while never letting us forget who we create for.