Project Outcomes

During our final meeting with our user, we provided her with the tool that now perfectly fit her pipette and qualitatively evaluated her comfort and level of upper-limb strain with and without the pipette. We saw a visible reduction in her use of her wrist tendons, and to quantify this value, we conducted tests with EMG electrodes. Despite having limitations such as a lack of pipette knob support, non-squishy material and a smooth surface (our user prefers a textured pipette to increase her grip), this add on was able to reduce our user’s hand intensity when handling her pipette while also being lightweight and sterilizable, all of which make it a helpful tool that can be further iterated to make optimal to many individuals that have upper-limb musculoskeletal disorders.

DBTL #9 (continued)

User Conversation

It is important to note that although you can see a difference in use of her palmaris longus muscles (the two visible tendons on the inner part of your wrist), this is essentially negligible in grip-related discussions as this muscle is very weak and only really helps with wrist flexion ([1]). Many people do not have it and function just fine. Grip force depends on a variety of things, including the normal angle of the thumb with respect to the grip as well as the positioning of fingers over a given surface area. Our design increases grip aperture (how much the hands open) which increases the force needed to hold a given object ([2]). However, the idea is that with this, the fingers also rest over a larger surface area which, our hypothesis was, decreases the total pressure on the palm and wrist. This hypothesis supported by a study that found grasping large cylindrical objects distribute the forces involved on the palm which reduces the degree of a “power grip” ([3]). But also, the counterintuitive benefit behind this increase in aperture is that although there is more force, this larger diameter places major opposing forces from the finger tips and thumb against each other, thereby reducing the total grip and force on the palm. Although there are multiple explanations for how gripping works, these are possible ones that describe why our user felt more comfortable with our MSK tool.

Given that the majority of these interpretations were qualitative, to test our hypothesis, we wanted to quantify the amount of contraction involved with gripping with and without our MSK tool. To do this, we used EMG electrodes and tested the mean percent muscle contraction with and without our MSK tool.

Test #6

EMG Electrode Measurements

As seen in the results, the EMG electrode measurements show a significant lower median EMG activity (contraction/gripping noted as maximal voluntary contraction (MVC)) in one subject and inconclusive results for the other two. They also show a significant reduction in % MVC when holding the pipette with the tool for Subject 1 and a significant increase in % MVC when pipetting for Subject 2, with insignificant differences in all other categories.

These results mostly support our qualitative observations with regards to gripping in our user, but the insignificant difference between the presence and lack of our tool can be accounted for by multiple things. One reason could be that measuring muscle activity not being the most standard and/or only way to quantify improvements in pipetting. Furthermore, our user expressed soreness and pain arises from repetition and continuous strain in the lab, however our EMG testing was not conducted at that equivalent level of strain, due to being tested before any lab work. Perhaps if measurements were taken after a substantial amount of repetition, there would be a notable result in alleviating muscle use.

However, the presence of a significant difference between mean percent MVC for one subject and differences in the median “mean percent MVC” among the remaining two subjects makes it important to further investigate the visible difference in muscle tendons used between pipetting with the tool and without as previously shown. Additionally, our user stated that she found the tool made holding the pipette more comfortable. She also expressed interest in incorporating this into her daily lab work as well as sharing it with her old lab. The aforementioned significant difference in mean percent MVC in one of our subjects coupled with the comfort our user has expressed with our add on makes this design a significant one that is worth taking through more iterations, ultimately yielding an optimal design that is able to help a diverse set of individuals.

Unexpected Benefit

In particular, one significant aspect of our design is that it is universal in terms of fitting onto various pipettes. We tested our latest print on four different brands of pipettes commonly found in labs, and our tool clicked onto all. Additionally, the curvature proved to hold onto each pipette without the addition of straps. This improves ease of use as well as reduces additional weight added onto the tool, and the PLA itself is also very lightweight, a quality our user also enjoyed. Although we initially thought to print in polyurethane, our tool was printed with PLA, which meets the threshold to be sterilizable according to a study ([4]), so it is functional in a laboratory setting.

DBTL #10

Mark 6

Although we initially believed the smaller prints we had (mark 2 and mark 4) were too small to be beneficial, our user liked them the most when testing without the pipette. She also said that while pipetting she did still like pipetting with the larger tool (mark 6), she thought it was slippery and requires some texture. We asked what would be the ideal size decrease, and she said the thicker side should be half of it’s current size; so that’s what we did.

Although this print failed, it is a perfect opportunity to visually show how we have a 10% in fill. All of our prints are 10% in fill, leading them to be very light, which is perfect for our user.

As well, this gave us time to come across a study that helps us greatly. It was found that greater contact area reduces pain in the hand caused by high pressure and pinching, and it also found that the contact area was greatest at the handle diameter of 51 mm or 58 mm ([3]). Our current mark 5 has a handle diameter of 59.26 mm, being only slightly larger than the optimal 58 mm. However, our mark 6 is has a handle diameter of 46.5 mm, which substantially smaller than the optimal 51 mm. Therefore, we decided to make a Mark 7 that is the same as Mark 6, just that it had a handle diameter of 51mm.

DBTL #11

Mark 7

Qualitative statements from Wet Lab Team

Considering a part of Inclusive Designs are to broaden to a larger audience after developing a tool that works for a representative of a group, we asked our Wet Lab Team for feedback on their thoughts. We showed them Mark 5 and Mark 7.

We learnt that although it can fit on other pipette’s it may not always fit well to work with the function of the pipette. For the Pipetteman brand model, the print made it more difficult to eject the pipette tip. However, they did say they enjoyed the shape, especially the smaller size. One person did say that the mark 5 was too slippery, and preferred the ribbing on mark 7, which indicates that ribbing design choice aided in the use of the tool

Based on this conversation, we knew that more work needs to be done to broaden the use of the tool. However, our team only had the capacity to target the MSK tool for our user and for the Rainin-Lite XLS pipette. Therefore, we encourage other teams to build from where we left off and modify the design to their own users needs, including for their own team members. That is why we included our CAD’s on our Gitlab to be accessed by anyone. All of our CADs, including mark 5, mark 6, and mark 7 can be found in there. As well, to make it easier for future teams, we also made a mark5_ribbed CAD, which is the mark 5 with the same ribbing found on mark 6 and mark 7.

Limitations of the Design

Although our MSK tool can attach onto a standard pipette produced by various different companies, we quickly recognized one drawback that would not be possible is making it universal in terms of functionality. As well, one of the requirements is that the volume number on a pipette is not obstructed by our MSK tool. However, different pipettes have different placements of their volumes, with some pipettes even having their designs to the side of the pipette, meaning one design will not be able to accommodate every companies placement. We therefore, targeted our design for our user’s specific needs such as the exact pipette she uses in her lab, yet did not have enough time to create a open space for the volume to be shown. Further limitations of our design include comfort aspects. Our user expressed the PLA was firmer than she would have liked, and making the tool softer would also make it easier for her to grip. Some potential materials we explored included polyurethane, as well as making a mold of the tool then filling it with silicone to create a silicone model of our tool. Unfortunately we did not have these materials accessible to our team, and were not able to order these supplies in our given time frame. Nonetheless, we explored the logistics of these materials but could not ultimately pursue physical prototypes of them.

Conclusion

Although there were some aspects of our design that still require improvements, we had successfully printed a tool that we may give to our user for her to incorporate into her wet lab work. There is still much to be explored. Feedback regarding long term use of the tool is still needed, and additional changes to the design will improve it’s functionality in the wet lab. Regardless, our main aim was to increase the visibility of inclusive design projects within the iGEM community, and inspire others to follow suit and use the same design framework for future projects. That is why we also documented the next two wiki pages; Alternative Inclusive Design Projects, which were project ideas that we did not pursue, and Best Practices for Inclusive Design Project, which describes the Inclusive Designs framework in detail, and includes what we learnt going through this process. All in all, we hope the principles we investigated can help future iGEM teams carry out more inclusive design projects so we can all collectively work towards making wet lab more accessible to all.