Investigation into the Effects of Backrest Angle and Stick Location on Female Strength

Objectives: The purpose of this study was to investigate the effects of backrest angle and hand maneuver direction on maximum hand strength and to recommend a strength value for the hand-controlled stick of an aircraft. Methods: Forty-eight female subjects were recruited to perform simulated forward–backward and adduction–abduction maneuvers using control sticks. Each subject was free from musculoskeletal disorders and pain. The independent variables included four control maneuvers (forward, backward, adduction, abduction), two right-hand control stick locations (central, side), and three backrest angles (90°, 103°, 108°). The dependent variable was maximum hand strength. Results: The maximum strength for forward maneuvers with both central and side sticks was strongest at a 90° backrest angle (p < 0.001). The maximum strength for adduction maneuvers with both central and side sticks was also strongest at a 90° backrest angle (p < 0.001). On the other hand, the highest strength was observed at a 108° backrest angle when pulling the stick backward (p < 0.001). The abduction strength was significantly stronger than the adduction strength with a central stick (p < 0.001), but the adduction strength was significantly stronger than the abduction strength with a side stick (p < 0.001–p = 0.017). The forward and abduction strength were significantly different in different locations (p < 0.001). The recommended strength in the Code of Federal Regulations (CFR) by the US FAA is higher than the strength values observed in this study. Conclusions: The backrest angle, directions, and location affected the muscular strength. The recommended values should be reevaluated and adjusted for Taiwanese pilots.

A Fully 3D-Printed Steerable Instrument for Minimally Invasive Surgery

In the field of medical instruments, additive manufacturing allows for a drastic reduction in the number of components while improving the functionalities of the final design. In addition, modifications for users’ needs or specific procedures become possible by enabling the production of single customized items. In this work, we present the design of a new fully 3D-printed handheld steerable instrument for laparoscopic surgery, which was mechanically actuated using cables. The pistol-grip handle is based on ergonomic principles and allows for single-hand control of both grasping and omnidirectional steering, while compliant joints and snap-fit connectors enable fast assembly and minimal part count. Additive manufacturing allows for personalization of the handle to each surgeon’s needs by adjusting specific dimensions in the CAD model, which increases the user’s comfort during surgery. Testing showed that the forces on the instrument handle required for steering and grasping were below 15 N, while the grasping force efficiency was calculated to be 10–30%. The instrument combines the advantages of additive manufacturing with regard to personalization and simplified assembly, illustrating a new approach to the design of advanced surgical instruments where the customization for a single procedure or user’s need is a central aspect.

Pengembangan Adaptive Hand Control Drive pada Mobil untuk Disabilitas Daksa

Disabilitas daksa merupakan kondisi adanya kerusakan atau gangguan pada tulang dan otot yang menghambat kegiatan individu. Adanya hambatan menyebabkan disabilitas daksa membutuhakan layanan khusus untuk memudahkan mobilitasnya. Salah satu caranya melalui pengembangan adaptive hand control drive pada mobil. Pengembangan alternative hand control pada mobil untuk disabilitas daksa inilah yang melatarbelakangi penelitian ini. Tujuannya adalah mengembangkan dan memodifikasi produk yang sudah ada sebelumnya. Metode yang digunakan dalam penelitian ini adalah metode penelitian dan pengembangan (R&D) yang menggunakan lima tahap dalam pelaksanaannya. Lima tahap tersebut antara lain; pengalaman lapangan dan kajian literatur, pengembangan desain awal, uji coba produk, revisi, validasi yang dilakukan oleh para ahli, kemudian pembuatan prototype modifikasi mobil dengan hand control drive. Subjek dalam penelitian ini adalah 3 orang dengan disabilitas daksa yang memiliki karakteristik berbeda. Teknik pengumpulan data yang digunakan adalah teknik wawancara dan dokumentasi, sedangkan untuk analisis data menggunakan teknik analisis data yang disajikan dalam bentuk deskriptif kualitatif. Dari hasil penelitian diperoleh data bahwa model 1 tuas yang diletakkan di sebelah kiri lebih aman dan memudahkan disabilitas daksa dalam mobilitas. Oleh karena itu, dalam memodifikasi alat transportasi bagi disabilitas daksa perlu diperhatikan karakteristik dan tingkat kebutuhan masing-masing individu, juga memperhatikan keamanan dan keselamatan.

Analyzing Midair Object Pointing Mappings for Smart Display Input

One common task when controlling smart displays is the manipulation of menu items. Given current examples of smart displays that support distant bare hand control, in this paper we explore menu item selection tasks with three different mappings of barehand movement to target selection. Through a series of experiments, we demonstrate that Positional mapping is faster than other mappings when the target is visible but requires many clutches in large targeting spaces. Rate-based mapping is, in contrast, preferred by participants due to its perceived lower effort, despite being slightly harder to learn initially. Tradeoffs in the design of target selection in smart tv displays are discussed.

In Usufruct to the Living

An especially underappreciated problem regarding philanthropic power concerns the way in which charitable gifts exercise control over future generations. Charitable bequests and trusts, which are popular instruments of donation, bind future generations to respect the wills of past donors. This chapter draws on views of Thomas Jefferson—noted critic of institutions that favor the dead over the living—to illustrate the problem of “dead-hand control.” Jefferson’s perspective helps us to appreciate that donations meant to benefit future persons may also mistreat them by imposing conditions on their use of resources. The chapter argues that generations have an interest in sovereignty over their common affairs that qualifies how resources can be donated across time. Though it ultimately defends the practice of intergenerational philanthropy, the chapter also shows how taking the value of sovereignty seriously recommends restrictions on the duration that donors can expect to have their wills honored.