Development Team Interview:
Exploring Moving Treatment Table

B dot Medical is a medical device startup manufacturing and selling a proton beam cancer treatment system. Our ultra-compact “Phemto” system reduces the size of the system, which typically stands at around 12 meters tall, to approximately one-third. By achieving this, we aim to make proton cancer therapy more accessible to a wider population.

However, B dot Medical’s endeavors go beyond mere downsizing of the irradiation device. We also developed a moving treatment table to enhance the efficiency of treatment rooms, allowing a larger number of patients to undergo proton beam therapy.

Let’s delve into the background and key points of the design by interviewing the team.

*Patient transport must be accompanied by medical staff, initiated and fixed at the destination by the operation of medical staff.

From left to right; Mizuguchi (Product designer), Minohara and Kubota (Development team)

Kubota: In the traditional treatment process, patients change clothes, and medical staff position the patient on the treatment table, aligning the area of tumor with the intended irradiation position. After receiving proton beam irradiation, patients change clothes once again and leave the room. Typically, all these steps occur within the treatment room. However, the task that truly requires the treatment room is only the irradiation itself.

Considering that the actual irradiation time is usually short, around 1 to 2 minutes, we pondered whether we could carry out the irradiation within the treatment room and handle the other steps in a separate room. This approach would enhance efficiency per treatment room, enabling more patients to receive treatment. That was the fundamental idea behind it.

Kubota: Achieving the required precision for positioning in proton beam therapy, which is less than a millimeter, is no easy feat. Based on a survey conducted by B dot Medical at a university hospital, we discovered that the positioning needed to be redone approximately once every five attempts. If we can perform this intricate positioning task outside the treatment room, it should reduce the treatment room occupancy time.

The challenge then becomes how to transport the patient to the treatment room without disturbing their position. To address this, we came up with the concept of the moving treatment table. This table shuttles the patient between the preparation room and the treatment room seamlessly, completing the positioning process outside the treatment room.

Once the treatment table arrives in the treatment room, it is firmly secured with an accuracy of approximately 1 millimeter. Then, using an arm, the position of the tabletop is finely adjusted, striving to achieve submillimeter precision.

Minohara: When developing the moving treatment table, our primary consideration was the comfort of the patients. To begin with, I did actually sit on an existing particle therapy treatment table and experienced the movements firsthand.

The human body detects horizontal rotational acceleration through the semicircular canals and senses linear acceleration in the direction of gravity through the otolith organs in the inner ears. These sensory systems are located within the ears. When the movement of the head is minimized, people feel less motion. Taking advantage of this characteristic, we control the movement of the treatment table by minimizing the motion of the part closest to the patient’s head during table or tabletop rotation, originating the movement from the feet.

Furthermore, sudden acceleration or deceleration can cause discomfort, anxiety, and even shift the patient’s position. However, moving at a consistently slow pace would hinder the efficiency we aim to achieve. So, what is the solution? An excellent example is high-rise building elevators—they ascend and descend at high speeds, but they adjust the speed to slow down just before stopping to prevent passenger anxiety. We adopt a similar approach, making careful adjustments to control the acceleration and deceleration when starting and stopping the treatment table.

Mizuguchi: In order to provide a sense of reassurance and usability for those who are unfamiliar with the moving treatment table, it is important to ensure that intuitive expectations align with the actual functionality.

One aspect we focused on is the shape of the vehicle body. Unmanned transport vehicles used in factories for carrying parts often have a square shape, which gives them a static appearance. Contrary to this, we incorporated rounded shapes at both ends of the vehicle body to indicate the driving direction and achieve a balance between curves and straight lines, creating a sense of security. Through this design approach, we aim to utilize the power of design to evoke emotions in users.

Moreover, in the overall operability design, we pay attention not only to the patient’s experience but also to the “emotions” of technicians and hospital staff. We consider the emotions operators experience while performing their tasks and design to optimize usability without interfering with those emotions. Through multiple iterations of verification with the development team members, who have clinical experience in particle therapy, we strived to create a design that achieves optimal usability.

I can’t wait for the day it is utilized for treatments for the patients, as it embodies the experience, knowledge, and ingenuity of B dot Medical.